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Although the positive effect that cellulose nanofibers (CNF) can have on paper strength is known, their effect on flocculation during papermaking is not well understood, and most relevant studies have been carried out in presence of only cationic starch. Flocculation is the key to ensuring retention of fibers, fines, and fillers, and furthermore floc properties have a great influence on paper quality. The aim of this research is to study the interactions between CNF and flocculants by assessing the effect of two types of CNF, from eucalyptus and corn, on the flocculation process induced by three different retention systems [a dual system, polyvinylamine (PVA), and cationic starch as reference]. The results showed that CNF interacted with the flocculants in different ways, affecting flocculation efficiency and floc properties. In general, addition of CNF increased floc stability and minimized overdosing effects. Moreover, presence of CNF increased floc size for given PVA dose; therefore, CNF addition could contribute to improve the wet end in the paper machine if combined with the optimal flocculant and dose., Economy and Competitiveness Ministry of Spain (MINECO), Depto. de Ingeniería Química y de Materiales, Fac. de Ciencias Químicas, TRUE, pub

One of the materials that has recently been used to remove environmental pollution from industrial effluents with photocatalytic technology is cobalt chromate (CoCr2O4) nanoparticles. An effective way to improve the photocatalytic properties of materials is to composite them with other photocatalysts to prevent recombination of electron-holes and accelerate the transfer of oxidation/reduction agents. Graphitic carbon nitride (g-C3N4) is an excellent choice due to its unique properties. In this research, CoCr2O4 and its composite with g-C3N4 (5, 10, and 15%) were synthesized by polyacrylamide gel method and characterized by X-ray diffraction, scanning electron microscopy, FTIR, UV–Vis spectroscopy techniques. The photocatalytic behavior of synthesized nanoparticles was investigated in the degradation process of methylene blue dye. The results showed that the composite samples have higher efficiency in photocatalytic activity than the pure CoCr2O4 sample. Using CoCr2O4-15 wt%g-C3N4 nanocomposite, after 80 min, methylene blue was completely degraded. The mechanism of degradation by CoCr2O4-g-C3N4 nanocomposite was the superoxide radical produced by the reaction of electrons with oxygen absorbed on the catalyst surface, as well as optically produced holes directly., QC 20230725

Cellulose nanofibers (CNF) have increasing relevance in different applications, for instance, in the paper industry as a sustainable strength additive. This application is especially beneficial for recycled paper, which reaches higher product quality despite its limitations. CNF change paper properties and also can affect the production process, especially the drainage stage, in which retention additives (RA) are commonly used to promote interaction of cellulose fibers. CNF probably interact with fibers and RA, affecting the drainage stage. However, these interactions vary depending on the type and flocculation mechanism of RA. This research is aimed at establishing possible synergies between CNF and RA to improve paper strength, avoiding negative effects on the drainage process. No further RA were used to retain CNF, taking advantage of the RA already used in the process. Polyvinylamine, chitosan, cationic starch, C-PAM, and C-PAM-B were selected as RA. CNF from eucalyptus kraft pulp and corn stalk organosolv pulp were tested. Strength properties of laboratory sheets were studied, and interactions were assessed by measuring Z-potential. Synergies between PVA, chitosan, C-PAM, and C-PAM-B with CNF were found. Drainage time decreased ranging between 30 and more than 40% using CNF. Strength depended on RA and formation quality. Among the studied options, CNF with C-PAM-B or chitosan resulted in the best formation and higher strengths with a significant drainage time reduction., Economy and Competitiveness Ministry of Spain (MINECO), Depto. de Ingeniería Química y de Materiales, Fac. de Ciencias Químicas, TRUE, pub

Paper packaging is commonly found in the form of paper and cardboard boxes, but recently paper packing is being used in food packaging, trays, beverage packaging and even paper straws, among others. Paper strength additives have been developed to increase the efficiency of the joint strength and the joint areas and potentially maintain bulk in paper products. In this thesis, a fundamental study of paper dry strength additives was performed involving kraft birch fibres and model cellulose materials to explore the interaction between strength additives and cellulose fibres. The same techniques used in paper strength additives were extended to the adsorption of fire-retardant polymers on fibres. Adsorption behaviours of cationic starch (CS) and anionic polyacrylamide (APAM) or anionic polyelectrolyte complexes (PECs) were studied on kraft birch fibres with different surface charges. It was found that the saturation adsorption of CS on birch fibres in 0.01 M NaCl showed a linear relationship with the surface charge of fibre, while the adsorption of APAM and PECs was independent of the surface charge of fibres. Higher surface charge of fibres expands the saturation adsorption capacity of strength additives, consequently, improves the tensile strength properties of handsheets made of kraft birch fibres with CS/APAM or CS/PECs. Bending stiffness of handsheets was improved by CS and boosted by PECs or APAM. In addition, sheet density was not significantly compromised by adding strength additives. Cationic strength additives were investigated on model cellulose surfaces, model cellulose nanofibrils filaments, and model cellulose beads. CSs produced an increase in the mass of the cellulose surface, while cationic PAMs led to a decrease in the total mass of cellulose surface determined by Quartz Crystal Microbalance with Dissipation monitoring. All types of strength additives affected the filament joints but in different ways, while most of them made filaments form intermixed, Cellulosafiberbaserade förpackningar, så som förpackningar av kartong, används flitigt för till exempel livsmedels- och dryckesförpackningar och snabbmatsförpackningar. På senare tid har även fiberbaserade material börjat an vändas för att göra sugrör. Tillsatsämnen, så som styrkeökande kemikalier, används vid tillverkning av papper och kartong för att förbättra produktens egenskaper. De styrkeökande kemikalierna är ofta utvecklade för att öka fogstyrkan och den totala fogarean, det vill säga den totala kontaktytan mellan överlappande fibrer. Detta bör helst uppnås i kombination med en hög bulk (låg densitet). Denna avhandling studerar på grundläggande nivå interaktionen mellan modellsystem av cellulosa samt cellulosafiber (sulfatfibrer från björk) och hur denna interaktion påverkas vid tillsats av en rad styrkekemikalier. Fibrer med olika initial ytladdning studerades med avseende på adsorption av katjonstärkelse, följt av efterföljande adsorption av anjonisk polyakrylamid eller anjoniska polyelektrolytkomplex. Resultaten visar att mättnadsadsorptionen av katjonstärkelse vid en jonstyrka motsvarande 0,01 M NaCl har linjärt proportionell mot fiberns ytladdning, medan den efterföljande adsorptionen av anjonisk polyakrylamid eller anjonisk polyakrylamid var oberoende av fibrernas initiala ytladdning. Högre fiberytladdning ökade mättnadsadsorptionen av styrkekemikalierna, vilket också förbättrade de mekaniska egenskaperna hos ark tillverkade efter adsorption av dessa kemikalier. Böjstyvheten hos arken förbättrades av tillsats av katjonstärkelse och ökade ytterligare vid ytterligare tillsats av både anjoniska polyelektrolytkomplex och anjonisk polyakrylamid. Arkens densitet förändrades inte nämnvärt till följd av styrkekemikalierna. Katjoniska styrkekemikalier undersöktes också på tre olika modellmaterial: filmer och kulor av regenererade cellulosa samt filament tillverkade av. På cellulosafilmerna studerades i detalj adsorptionen av styrkekemikalierna (katjonstäke, QC 2022-12-20Embargo godkänt Mikael Lindström, skolchef CBH, via e-post 2022-12-20

Paper packaging is commonly found in the form of paper and cardboard boxes, but recently paper packing is being used in food packaging, trays, beverage packaging and even paper straws, among others. Paper strength additives have been developed to increase the efficiency of the joint strength and the joint areas and potentially maintain bulk in paper products. In this thesis, a fundamental study of paper dry strength additives was performed involving kraft birch fibres and model cellulose materials to explore the interaction between strength additives and cellulose fibres. The same techniques used in paper strength additives were extended to the adsorption of fire-retardant polymers on fibres. Adsorption behaviours of cationic starch (CS) and anionic polyacrylamide (APAM) or anionic polyelectrolyte complexes (PECs) were studied on kraft birch fibres with different surface charges. It was found that the saturation adsorption of CS on birch fibres in 0.01 M NaCl showed a linear relationship with the surface charge of fibre, while the adsorption of APAM and PECs was independent of the surface charge of fibres. Higher surface charge of fibres expands the saturation adsorption capacity of strength additives, consequently, improves the tensile strength properties of handsheets made of kraft birch fibres with CS/APAM or CS/PECs. Bending stiffness of handsheets was improved by CS and boosted by PECs or APAM. In addition, sheet density was not significantly compromised by adding strength additives. Cationic strength additives were investigated on model cellulose surfaces, model cellulose nanofibrils filaments, and model cellulose beads. CSs produced an increase in the mass of the cellulose surface, while cationic PAMs led to a decrease in the total mass of cellulose surface determined by Quartz Crystal Microbalance with Dissipation monitoring. All types of strength additives affected the filament joints but in different ways, while most of them made filaments form intermixed, Cellulosafiberbaserade förpackningar, så som förpackningar av kartong, används flitigt för till exempel livsmedels- och dryckesförpackningar och snabbmatsförpackningar. På senare tid har även fiberbaserade material börjat an vändas för att göra sugrör. Tillsatsämnen, så som styrkeökande kemikalier, används vid tillverkning av papper och kartong för att förbättra produktens egenskaper. De styrkeökande kemikalierna är ofta utvecklade för att öka fogstyrkan och den totala fogarean, det vill säga den totala kontaktytan mellan överlappande fibrer. Detta bör helst uppnås i kombination med en hög bulk (låg densitet). Denna avhandling studerar på grundläggande nivå interaktionen mellan modellsystem av cellulosa samt cellulosafiber (sulfatfibrer från björk) och hur denna interaktion påverkas vid tillsats av en rad styrkekemikalier. Fibrer med olika initial ytladdning studerades med avseende på adsorption av katjonstärkelse, följt av efterföljande adsorption av anjonisk polyakrylamid eller anjoniska polyelektrolytkomplex. Resultaten visar att mättnadsadsorptionen av katjonstärkelse vid en jonstyrka motsvarande 0,01 M NaCl har linjärt proportionell mot fiberns ytladdning, medan den efterföljande adsorptionen av anjonisk polyakrylamid eller anjonisk polyakrylamid var oberoende av fibrernas initiala ytladdning. Högre fiberytladdning ökade mättnadsadsorptionen av styrkekemikalierna, vilket också förbättrade de mekaniska egenskaperna hos ark tillverkade efter adsorption av dessa kemikalier. Böjstyvheten hos arken förbättrades av tillsats av katjonstärkelse och ökade ytterligare vid ytterligare tillsats av både anjoniska polyelektrolytkomplex och anjonisk polyakrylamid. Arkens densitet förändrades inte nämnvärt till följd av styrkekemikalierna. Katjoniska styrkekemikalier undersöktes också på tre olika modellmaterial: filmer och kulor av regenererade cellulosa samt filament tillverkade av. På cellulosafilmerna studerades i detalj adsorptionen av styrkekemikalierna (katjonstäke, QC 2022-12-20Embargo godkänt Mikael Lindström, skolchef CBH, via e-post 2022-12-20

Paper packaging is commonly found in the form of paper and cardboard boxes, but recently paper packing is being used in food packaging, trays, beverage packaging and even paper straws, among others. Paper strength additives have been developed to increase the efficiency of the joint strength and the joint areas and potentially maintain bulk in paper products. In this thesis, a fundamental study of paper dry strength additives was performed involving kraft birch fibres and model cellulose materials to explore the interaction between strength additives and cellulose fibres. The same techniques used in paper strength additives were extended to the adsorption of fire-retardant polymers on fibres. Adsorption behaviours of cationic starch (CS) and anionic polyacrylamide (APAM) or anionic polyelectrolyte complexes (PECs) were studied on kraft birch fibres with different surface charges. It was found that the saturation adsorption of CS on birch fibres in 0.01 M NaCl showed a linear relationship with the surface charge of fibre, while the adsorption of APAM and PECs was independent of the surface charge of fibres. Higher surface charge of fibres expands the saturation adsorption capacity of strength additives, consequently, improves the tensile strength properties of handsheets made of kraft birch fibres with CS/APAM or CS/PECs. Bending stiffness of handsheets was improved by CS and boosted by PECs or APAM. In addition, sheet density was not significantly compromised by adding strength additives. Cationic strength additives were investigated on model cellulose surfaces, model cellulose nanofibrils filaments, and model cellulose beads. CSs produced an increase in the mass of the cellulose surface, while cationic PAMs led to a decrease in the total mass of cellulose surface determined by Quartz Crystal Microbalance with Dissipation monitoring. All types of strength additives affected the filament joints but in different ways, while most of them made filaments form intermixed, Cellulosafiberbaserade förpackningar, så som förpackningar av kartong, används flitigt för till exempel livsmedels- och dryckesförpackningar och snabbmatsförpackningar. På senare tid har även fiberbaserade material börjat an vändas för att göra sugrör. Tillsatsämnen, så som styrkeökande kemikalier, används vid tillverkning av papper och kartong för att förbättra produktens egenskaper. De styrkeökande kemikalierna är ofta utvecklade för att öka fogstyrkan och den totala fogarean, det vill säga den totala kontaktytan mellan överlappande fibrer. Detta bör helst uppnås i kombination med en hög bulk (låg densitet). Denna avhandling studerar på grundläggande nivå interaktionen mellan modellsystem av cellulosa samt cellulosafiber (sulfatfibrer från björk) och hur denna interaktion påverkas vid tillsats av en rad styrkekemikalier. Fibrer med olika initial ytladdning studerades med avseende på adsorption av katjonstärkelse, följt av efterföljande adsorption av anjonisk polyakrylamid eller anjoniska polyelektrolytkomplex. Resultaten visar att mättnadsadsorptionen av katjonstärkelse vid en jonstyrka motsvarande 0,01 M NaCl har linjärt proportionell mot fiberns ytladdning, medan den efterföljande adsorptionen av anjonisk polyakrylamid eller anjonisk polyakrylamid var oberoende av fibrernas initiala ytladdning. Högre fiberytladdning ökade mättnadsadsorptionen av styrkekemikalierna, vilket också förbättrade de mekaniska egenskaperna hos ark tillverkade efter adsorption av dessa kemikalier. Böjstyvheten hos arken förbättrades av tillsats av katjonstärkelse och ökade ytterligare vid ytterligare tillsats av både anjoniska polyelektrolytkomplex och anjonisk polyakrylamid. Arkens densitet förändrades inte nämnvärt till följd av styrkekemikalierna. Katjoniska styrkekemikalier undersöktes också på tre olika modellmaterial: filmer och kulor av regenererade cellulosa samt filament tillverkade av. På cellulosafilmerna studerades i detalj adsorptionen av styrkekemikalierna (katjonstäke, QC 2022-12-20Embargo godkänt Mikael Lindström, skolchef CBH, via e-post 2022-12-20

Paper packaging is commonly found in the form of paper and cardboard boxes, but recently paper packing is being used in food packaging, trays, beverage packaging and even paper straws, among others. Paper strength additives have been developed to increase the efficiency of the joint strength and the joint areas and potentially maintain bulk in paper products. In this thesis, a fundamental study of paper dry strength additives was performed involving kraft birch fibres and model cellulose materials to explore the interaction between strength additives and cellulose fibres. The same techniques used in paper strength additives were extended to the adsorption of fire-retardant polymers on fibres. Adsorption behaviours of cationic starch (CS) and anionic polyacrylamide (APAM) or anionic polyelectrolyte complexes (PECs) were studied on kraft birch fibres with different surface charges. It was found that the saturation adsorption of CS on birch fibres in 0.01 M NaCl showed a linear relationship with the surface charge of fibre, while the adsorption of APAM and PECs was independent of the surface charge of fibres. Higher surface charge of fibres expands the saturation adsorption capacity of strength additives, consequently, improves the tensile strength properties of handsheets made of kraft birch fibres with CS/APAM or CS/PECs. Bending stiffness of handsheets was improved by CS and boosted by PECs or APAM. In addition, sheet density was not significantly compromised by adding strength additives. Cationic strength additives were investigated on model cellulose surfaces, model cellulose nanofibrils filaments, and model cellulose beads. CSs produced an increase in the mass of the cellulose surface, while cationic PAMs led to a decrease in the total mass of cellulose surface determined by Quartz Crystal Microbalance with Dissipation monitoring. All types of strength additives affected the filament joints but in different ways, while most of them made filaments form intermixed, Cellulosafiberbaserade förpackningar, så som förpackningar av kartong, används flitigt för till exempel livsmedels- och dryckesförpackningar och snabbmatsförpackningar. På senare tid har även fiberbaserade material börjat an vändas för att göra sugrör. Tillsatsämnen, så som styrkeökande kemikalier, används vid tillverkning av papper och kartong för att förbättra produktens egenskaper. De styrkeökande kemikalierna är ofta utvecklade för att öka fogstyrkan och den totala fogarean, det vill säga den totala kontaktytan mellan överlappande fibrer. Detta bör helst uppnås i kombination med en hög bulk (låg densitet). Denna avhandling studerar på grundläggande nivå interaktionen mellan modellsystem av cellulosa samt cellulosafiber (sulfatfibrer från björk) och hur denna interaktion påverkas vid tillsats av en rad styrkekemikalier. Fibrer med olika initial ytladdning studerades med avseende på adsorption av katjonstärkelse, följt av efterföljande adsorption av anjonisk polyakrylamid eller anjoniska polyelektrolytkomplex. Resultaten visar att mättnadsadsorptionen av katjonstärkelse vid en jonstyrka motsvarande 0,01 M NaCl har linjärt proportionell mot fiberns ytladdning, medan den efterföljande adsorptionen av anjonisk polyakrylamid eller anjonisk polyakrylamid var oberoende av fibrernas initiala ytladdning. Högre fiberytladdning ökade mättnadsadsorptionen av styrkekemikalierna, vilket också förbättrade de mekaniska egenskaperna hos ark tillverkade efter adsorption av dessa kemikalier. Böjstyvheten hos arken förbättrades av tillsats av katjonstärkelse och ökade ytterligare vid ytterligare tillsats av både anjoniska polyelektrolytkomplex och anjonisk polyakrylamid. Arkens densitet förändrades inte nämnvärt till följd av styrkekemikalierna. Katjoniska styrkekemikalier undersöktes också på tre olika modellmaterial: filmer och kulor av regenererade cellulosa samt filament tillverkade av. På cellulosafilmerna studerades i detalj adsorptionen av styrkekemikalierna (katjonstäke, QC 2022-12-20Embargo godkänt Mikael Lindström, skolchef CBH, via e-post 2022-12-20

Amino-Li-resin is a new and unique polyacrylamide resin presented in the form of fibers and is found to be well suited for solid-phase peptide chemistry. Although amino-Li-resin swells much better in polar solvents, it is also compatible with some non-polar solvents. It comes with a high loading of functional amino groups, thus maximizing its productivity in terms of the amount of peptide per gram of resin. In addition to its mechanical stability, this resin shows excellent stability in basic and acidic reagents; thus, allowing its broad applicability for the synthesis of a wide range of biomolecules. Finally, the appropriateness of amino-Li-resin for solid-phase peptide synthesis (SPPS) has been demonstrated for the synthesis of several model peptides, including difficult sequences and those containing hindered amino acids, all of which afforded excellent crude purity, as shown by high-performance liquid chromatography (HPLC) analysis.

IntroductionCell structure and migration is impacted by the mechanical properties and geometry of the cell adhesive environment. Most studies to date investigating the effects of 3D environments on cells have not controlled geometry at the single-cell level, making it difficult to understand the influence of 3D environmental cues on single cells. Here, we developed microwell platforms to investigate the effects of 2D vs. 3D geometries on single-cell F-actin and nuclear organization.MethodsWe used microfabrication techniques to fabricate three polyacrylamide platforms: 3D microwells with a 3D adhesive environment (3D/3D), 3D microwells with 2D adhesive areas at the bottom only (3D/2D), and flat 2D gels with 2D patterned adhesive areas (2D/2D). We measured geometric swelling and Young's modulus of the platforms. We then cultured C2C12 myoblasts on each platform and evaluated the effects of the engineered microenvironments on F-actin structure and nuclear shape.ResultsWe tuned the mechanical characteristics of the microfabricated platforms by manipulating the gel formulation. Crosslinker ratio strongly influenced geometric swelling whereas total polymer content primarily affected Young's modulus. When comparing cells in these platforms, we found significant effects on F-actin and nuclear structures. Our analysis showed that a 3D/3D environment was necessary to increase actin and nuclear height. A 3D/2D environment was sufficient to increase actin alignment and nuclear aspect ratio compared to a 2D/2D environment.ConclusionsUsing our novel polyacrylamide platforms, we were able to decouple the effects of 3D confinement and adhesive environment, finding that both influenced actin and nuclear structure.

Fertigation using vinasse, a high nutrient residue, is a viable form of complementary soil nutrition. However, it represents a dangerous risk of contamination if not properly disposed of. The objective of this study was to evaluate the irrigation and fertigation uniformity using vinasse in a drip irrigation system with and without the addition of polyacrylamide (friction-reducing polymer) applied at a concentration of 0.01 kg m-3 (10 mg L´-1). The tests consisted of collecting flow from 16 drippers in the system. Four were selected from each of the four lateral lines (first emitter, those located at 1/3 and 2/3 of the length, and the last one). Uniformity was obtained by the coefficient of distribution uniformity (CDU), Christiansen’s uniformity coefficient (CUC), the total coefficient of variation (CVt), and the statistical uniformity coefficient (SUC). The CUC values after the addition of the polymer were 2.33% and 2.1% higher for water and vinasse, respectively. For the CDU, the addition of the polymer resulted in values of 6.07% and 5.3% higher for water and vinasse, respectively, and the SUC resulted in values of 3.99% and 3.83% for water and vinasse, respectively. We concluded that vinasse showed a lower average uniformity compared to water. However, when the friction-reducing agent was added, an increase was observed in the average uniformity in the drip irrigation system., La fertirrigación con vinaza, un residuo rico en nutrientes, es una forma viable de nutrición complementaria del suelo. Sin embargo, representa un riesgo peligroso de contaminación si no se elimina correctamente. El objetivo de este estudio fue evaluar la uniformidad del riego y fertirrigación mediante el uso de vinaza en un sistema de riego por goteo con y sin la adición de poliacrilamida (polímero reductor de fricción) aplicada a una concentración de 0.01 kg m-3 (10 mg L-1). Los ensayos consistieron en recolectar el flujo de 16 goteros en el sistema. Se seleccionaron cuatro de cada una de las cuatro líneas laterales (primer emisor, los ubicados a 1/3 y 2/3 de la longitud, y el último). La uniformidad se obtuvo mediante el coeficiente de uniformidad de distribución (CUD), el coeficiente de uniformidad de Christiansen (CUC), el coeficiente de variación total (CVt) y el coeficiente de uniformidad estadística (CUE). Los valores de CUC después de la adición del polímero fueron un 2.33% y un 2.1% más altos para el agua y la vinaza, respectivamente. Para el CUD, la adición del polímero resultó en valores de 6.07% y 5.3% más altos para agua y vinaza, respectivamente, y el CUE resultó en valores de 3.99% y 3.83% para agua y vinaza, respectivamente. Se concluyó que la vinaza presentó una uniformidad promedio menor en comparación con el agua. Sin embargo, cuando se agregó el agente reductor de fricción, hubo un aumento en la uniformidad promedio en el sistema de riego por goteo.

The specific interactions between polyacrylamide brushes composed of polyacrylamide chains tethered to montmorillonite particles (Mt-g-PAm) and the individual components of immiscible ethylene-propylene-diene modified with sorbic acid (EPDM) and methyl vinyl silicone (MVQ) blends were studied. The effect of various lengths of PAm chains and their grafting density on montmorillonite (Mt) surface was investigated. It was determined that, due to interactions generated within the system through carboxyl and amide groups the brush particles were selectively located at the EPDM/MVQ interphase and in the EPDM phase. Furthermore, the longer PAm chains resulted in an increase of the glass transition of EPDM, unification of blend morphology, and the reduction of crystallinity of the MVQ phase. Therefore, precisely designed polymer brushes could be considered as novel functional compatibilizers, that provide a new tool for the future material designing. © 2021 Elsevier Ltd

Real-time monitoring of wound healing remains a major challenge in clinical tissue regeneration, calling the need for the development of biomaterial-guided on-site monitoring wound healing technology. In this study, multifunctional double colorimetry-integrated polyacrylamide-quaternary ammonium chitosan-carbon quantum dots (CQDs)-phenol red hydrogels are presented, aiming to simultaneously detect the wound pH level, reduce bacterial infection, and promote wound healing. The hybridization of CQDs and pH indicator (phenol red) with the hydrogels enables their high responsiveness, reversibility, and accurate indication of pH variability to reflect the dynamic wound status in the context of both ultraviolet and visible light. Furthermore, these visual images can be collected by smartphones and converted into on-site wound pH signals, allowing for a real-time evaluation of the wound dynamic conditions in a remote approach. Notably, the hydrogels exhibit excellent hemostatic and adhesive properties, maintain sufficient wound moisture, and promote wound healing via their high antibacterial activity (against Staphylococcus Aureus, and Escherichia Coli) and skin repair function. Overall, the resulting hydrogels have high potential as a novel smart and flexible wound dressing platform for theranostic skin regeneration.

IntroductionCell structure and migration is impacted by the mechanical properties and geometry of the cell adhesive environment. Most studies to date investigating the effects of 3D environments on cells have not controlled geometry at the single-cell level, making it difficult to understand the influence of 3D environmental cues on single cells. Here, we developed microwell platforms to investigate the effects of 2D vs. 3D geometries on single-cell F-actin and nuclear organization.MethodsWe used microfabrication techniques to fabricate three polyacrylamide platforms: 3D microwells with a 3D adhesive environment (3D/3D), 3D microwells with 2D adhesive areas at the bottom only (3D/2D), and flat 2D gels with 2D patterned adhesive areas (2D/2D). We measured geometric swelling and Young's modulus of the platforms. We then cultured C2C12 myoblasts on each platform and evaluated the effects of the engineered microenvironments on F-actin structure and nuclear shape.ResultsWe tuned the mechanical characteristics of the microfabricated platforms by manipulating the gel formulation. Crosslinker ratio strongly influenced geometric swelling whereas total polymer content primarily affected Young's modulus. When comparing cells in these platforms, we found significant effects on F-actin and nuclear structures. Our analysis showed that a 3D/3D environment was necessary to increase actin and nuclear height. A 3D/2D environment was sufficient to increase actin alignment and nuclear aspect ratio compared to a 2D/2D environment.ConclusionsUsing our novel polyacrylamide platforms, we were able to decouple the effects of 3D confinement and adhesive environment, finding that both influenced actin and nuclear structure.

Polymers with controlled molecular weights and sequences are expected to be functional polymers. Synthesis of multi-block glycopolymers were investigated to fabricate the functional biopolymers. The glycopolymers having mannose side chain with polyacrylamide backbone were polymerized with acrylamide derivatives. We synthesized of multi-block glycopolymers consisting of up to 9 blocks. The polymerization was conducted with rapid reaction in high yield. The multi-block glycopolymers with glycoblock at the both ends were prepared with narrow molecular weights dispersity. Molecular recognition of glycopolymers were analysed using mannose recognition protein of concanavalin A.

Pyrethroid and neonicotinoid pesticides control an array of insect pests in leafy greens, but there are concerns about the off-site movement and potential water quality impacts of these chemicals. Effective on-farm management practices can eliminate aquatic toxicity and pesticides in runoff. This project evaluated an integrated vegetated treatment system (VTS), including the use of polyacrylamide (PAM), for minimizing the toxicity of imidacloprid and permethrin pesticides in runoff. The VTS incorporated a sediment trap to remove coarse particles, a grass-lined ditch with compost swales to remove suspended sediment and insecticides, and granulated activated carbon (GAC) or biochar to remove residual insecticides. Runoff was sampled throughout the VTS and analyzed for pesticide concentrations, and aquatic toxicity using the midge Chironomusdilutus and the amphipod Hyalella azteca. In simulated runoff experiments, the VTS reduced suspended sediment load by 88%, and imidacloprid and permethrin load by 97% and 99%, respectively. In runoff events from a conventionally grown lettuce field, suspended sediment load was reduced by 98%, and insecticide load by 99%. Toxicity was significantly reduced in approximately half of the simulated runoff events, and most of the lettuce runoff events. Integrated vegetated treatment systems that include components for treating soluble and hydrophobic pesticides are vital tools for reducing pesticide load and occurrence of pesticide-related toxicity.

Corneal endothelial cells (CECs) have limited proliferation ability leading to corneal endothelium (CE) dysfunction and eventually vision loss when cell number decreases below a critical level. Although transplantation is the main treatment method, donor shortage problem is a major bottleneck. The transplantation of in vitro developed endothelial cells with desirable density is a promising idea. Designing cell substrates that mimic the native CE microenvironment is a substantial step to achieve this goal. In the presented study, we prepared polyacrylamide (PA) cell substrates that have a microfabricated topography inspired by the dimensions of CECs. Hydrogel surfaces were prepared via two different designs with small and large patterns. Small patterned hydrogels have physiologically relevant hexagon densities (∼2000 hexagons/mm²), whereas large patterned hydrogels have sparsely populated hexagons (∼400 hexagons/mm²). These substrates have similar elastic modulus of native Descemet’s membrane (DM; ∼50 kPa) and were modified with Collagen IV (Col IV) to have biochemical content similar to native DM. The behavior of bovine corneal endothelial cells on these substrates was investigated and results show that cell proliferation on small patterned substrates was significantly (p = 0.0004) higher than the large patterned substrates. Small patterned substrates enabled a more densely populated cell monolayer compared to other groups (p = 0.001 vs. flat and p < 0.0001 vs. large patterned substrates). These results suggest that generating bioinspired surface topographies augments the formation of CE monolayers with the desired cell density, addressing the in vitro development of CE layers.

The specific interactions between polyacrylamide brushes composed of polyacrylamide chains tethered to montmorillonite particles (Mt-g-PAm) and the individual components of immiscible ethylene-propylene-diene modified with sorbic acid (EPDM) and methyl vinyl silicone (MVQ) blends were studied. The effect of various lengths of PAm chains and their grafting density on montmorillonite (Mt) surface was investigated. It was determined that, due to interactions generated within the system through carboxyl and amide groups the brush particles were selectively located at the EPDM/MVQ interphase and in the EPDM phase. Furthermore, the longer PAm chains resulted in an increase of the glass transition of EPDM, unification of blend morphology, and the reduction of crystallinity of the MVQ phase. Therefore, precisely designed polymer brushes could be considered as novel functional compatibilizers, that provide a new tool for the future material designing. © 2021 Elsevier Ltd

С помощью объемного варианта сорбционного метода изучена сорбция воды пленками ПАА, ПАК, ПМАК и смесями ПАА-ПАК, ПАА-ПМАК разного состава. Измерены теплоты смешения образцов с водой с использованием микрокалориметра типа Тиана-Кальве. Рассчитаны разности химических потенциалов воды ∆µ1, полимеров и смесей ∆µ2, энергии Гиббса смешения полимеров с водой ∆gm. Определены энергии Гиббса, энтальпии и энтропии смешения компонентов в полимерных композициях. Показано, что сорбционная способность систем ПАА-ПАК, ПАА-ПМАК определяется их структурой и сродством к воде. ПАК ведет себя как плотноупакованный полимер, имеющий высокое сродство к воде, а сорбция воды ПМАК свидетельствует о менее плотной упаковке цепей и меньшему сродству к воде. Сорбция воды смесями немонотонно изменяется с составом композиции. Установлено, что смешение всех систем с водой сопровождается уменьшением энергий Гиббса (Δgm < 0), величина ∂2g/∂ω22 > 0, что указывает на образование термодинамически устойчивых систем. Чем б льше сорбционная способность полимера или смеси, тем более отрицательны величины Δgm. Обнаружено, что растворение в воде всех изученных систем сопровождается экзотермическим тепловым эффектом. Отклонения энтальпий смесей от аддитивности положительны для всех систем кроме смеси ПАА-ПМАК с ωПАА < 0,2, что свидетельствует о хорошем взаимодействии полимеров друг с другом. Установлено, что энергии Гиббса смешения ПАА с ПАК и ПМАК полученные двумя методами: с помощью расчета по энергиям Гиббса растворения систем и с помощью уравнения Флори-Хаггинса, хорошо коррелируют друг с другом. Показано, что что смешение ПАА с ПАК сопровождается экзотермическим тепловым эффектом во всей области составов и уменьшением энергии Гиббса вплоть до содержания 90% ПАА. При этом ∆gx и ∆hx близки по величине, и энтропийный вклад в совместимость компонентов T∆sx очень невелик. Таким образом, термодинамическая совместимость ПАА с ПАК обусловлена, главным образом, энергетическим взаимодействием компонентов. Обнаружено, Using the volumetric version of the sorption method, water sorption was studied with PAM, PAA, PMAA films and PAM-PAA, PAM-PMAA mixtures of various compositions. The heats of mixing samples with water were measured using a Tiana-Calve type microcalorimeter. The differences between the chemical potentials of water ∆µ1, polymers and mixtures ∆µ2, Gibbs energy of mixing polymers with water ∆gm are calculated. The Gibbs energies, enthalpy, and entropy of mixing of the components in polymer compositions are determined. It was shown that the sorption ability of PAM-PAA, PAM-PMAK systems is determined by their structure and affinity for water. PAA behaves as a close-packed polymer with a high affinity for water, and the sorption of PMAA water indicates a less dense packing of chains and a lower affinity for water. Sorption of water mixtures non-monotonously changes with the composition. It was found that the mixing of all systems with water is accompanied by a decrease in Gibbs energies (Δgm <0), the value ∂2g/∂ω22> 0, which indicates the formation of thermodynamically stable systems. The greater the sorption capacity of the polymer or mixture, the more negative the Δgm values. It was found that dissolution of all the studied systems in water is accompanied by an exothermic thermal effect. Deviations of the enthalpies of the mixtures from additivity are positive for all systems except the PAM-PMAA mixture with ωPAM <0.2, which indicates a good interaction of the polymers with each other. It was established that the Gibbs energies of mixing PAM with PAA and PMAA were obtained by two methods: using the Gibbs energies of dissolution of systems and using the Flory-Huggins equation, they correlate well with each other. It was shown that the mixing of PAM with PAA is accompanied by an exothermic thermal effect in the entire composition range and a decrease in Gibbs energy up to the content of 90% PAM. Moreover, ∆gx and ∆hx are close in magnitude, and the entropy contribution to

В данной работе изучена эффективность сбора образцов на основе полиакриламида для разделения поливинилацетата флотационным методом. В ходе этого процесса были выбраны оптимальные концентрации собирающих реагентов и оптимальный диапазон рН растворов, а также оценена эффективность представленных образцов. Установлено, что коллекторы проявляют максимальную эффективность при концентрации 2 мг/л. Максимальная эффективность наблюдается в щелочной среде и может достигать 99% в зависимости от условий процесса., In this paper the effectiveness of polyacrylamide-based collecting samples for the separation of polyvinyl acetate by flotation method is studied. During this process, the optimal concentrations of collecting reagents and the optimal pH range of solutions were selected, and the efficiency of the presented samples was evaluated. It was determined that the collectors show maximum efficiency at a concentration of 2 mg/l. Maximum efficiency is observed in an alkaline environment and can reach 99% depending on the conditions of the process.

Polyacrylamide ferrogels with embedded magnetic nanoparticles of metallic nickel (Ni) and nanoparticles of nickel coated with a carbon shell (Ni@C) were synthesized by radical polymerization in water. The effect of the carbon shell on the interaction of Ni and Ni@C nanoparticles with polyacrylamide matrix and on swelling ratio of the ferrogels has been studied. The deposition of carbon on the surface of Ni nanoparticles worsens their interaction with polyacrylamide but at the same time elevates the water uptake by ferrogels.

Optimal combination of stem cells and biocompatible support material is a promising strategy for successful tissue engineering. The required differentiation of stem cells is crucial for functionality of engineered tissues and can be regulated by chemical and physical cues. Here we examined how boundary cap neural crest stem cells (bNCSCs) are affected when cultured in the same medium, but on collagen- or laminin-polyacrylamide (PAA) scaffolds of different stiffness (0.5, 1, or similar to 7 kPa). bNCSCs displayed marked differences in their ability to attach, maintain a large cell population and differentiate, depending on scaffold stiffness. These findings show that the design of physical cues is an important parameter to achieve optimal stem cell properties for tissue repair and engineering.

Optimal combination of stem cells and biocompatible support material is a promising strategy for successful tissue engineering. The required differentiation of stem cells is crucial for functionality of engineered tissues and can be regulated by chemical and physical cues. Here we examined how boundary cap neural crest stem cells (bNCSCs) are affected when cultured in the same medium, but on collagen- or laminin-polyacrylamide (PAA) scaffolds of different stiffness (0.5, 1, or similar to 7 kPa). bNCSCs displayed marked differences in their ability to attach, maintain a large cell population and differentiate, depending on scaffold stiffness. These findings show that the design of physical cues is an important parameter to achieve optimal stem cell properties for tissue repair and engineering.

Optimal combination of stem cells and biocompatible support material is a promising strategy for successful tissue engineering. The required differentiation of stem cells is crucial for functionality of engineered tissues and can be regulated by chemical and physical cues. Here we examined how boundary cap neural crest stem cells (bNCSCs) are affected when cultured in the same medium, but on collagen- or laminin-polyacrylamide (PAA) scaffolds of different stiffness (0.5, 1, or similar to 7 kPa). bNCSCs displayed marked differences in their ability to attach, maintain a large cell population and differentiate, depending on scaffold stiffness. These findings show that the design of physical cues is an important parameter to achieve optimal stem cell properties for tissue repair and engineering.

A comparative study of polyacrylamide and potato starch as selective flocculants for the beneficiation of low-grade iron-ore slimes (head sample: 52.6% Fe) from Barsua mines, Sundergarh, Odisha, India is presented. Characterisation of the slimes is performed using chemical analyses, particle size distribution, optical microscopy, X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis and scanning electron microscopy/energy-dispersive X-ray spectroscopy. Using a feed size of -75 micrometres, the effects of pulp density, flocculant dosage and pH on the settling rate, grade, recovery, and separation efficiency are described. The results indicate that, under optimum conditions of pH 9, pulp density 20% and polyacrylamide dosage 45 ppm, an iron grade of 65.90% and recovery of 91.04% with a separation efficiency of 69.59% are achieved. A statistical analysis of the experimental data using ANOVA and a mechanistic investigation of the adsorption of the flocculants on the mineral surfaces (haematite and goethite) by measuring the FTIR spectra and XRD patterns of the feed sample and concentrates are discussed., A comparative study of polyacrylamide and potato starch as selective flocculants for the beneficiation of low-grade iron-ore slimes (head sample: 52.6% Fe) from Barsua mines, Sundergarh, Odisha, India is presented. Characterisation of the slimes is performed using chemical analyses, particle size distribution, optical microscopy, X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis and scanning electron microscopy/energy-dispersive X-ray spectroscopy. Using a feed size of -75 micrometres, the effects of pulp density, flocculant dosage and pH on the settling rate, grade, recovery, and separation efficiency are described. The results indicate that, under optimum conditions of pH 9, pulp density 20% and polyacrylamide dosage 45 ppm, an iron grade of 65.90% and recovery of 91.04% with a separation efficiency of 69.59% are achieved. A statistical analysis of the experimental data using ANOVA and a mechanistic investigation of the adsorption of the flocculants on the mineral surfaces (haematite and goethite) by measuring the FTIR spectra and XRD patterns of the feed sample and concentrates are discussed.

Organic binders have been used as alternative to bentonite in the iron ore pelletising process mainly because it burns without leaving residue in the pellet. There are two main types of organic binders, those based on cellulose and those based on polyacrylamide structures. The purpose of this investigation was to explore how an organic binder based on carboxymethyl cellulose structure improves the compressive strength of wet and dry pellets. Thus, the interaction between the binder Peridur and the mineral surface and the content of goethite in two Brazilian pellet feed were investigated. This work has found that the same organic binder performs differently depending on the type of iron ore processed. (Authors.), Organic binders have been used as alternative to bentonite in the iron ore pelletising process mainly because it burns without leaving residue in the pellet. There are two main types of organic binders, those based on cellulose and those based on polyacrylamide structures. The purpose of this investigation was to explore how an organic binder based on carboxymethyl cellulose structure improves the compressive strength of wet and dry pellets. Thus, the interaction between the binder Peridur and the mineral surface and the content of goethite in two Brazilian pellet feed were investigated. This work has found that the same organic binder performs differently depending on the type of iron ore processed. (Authors.)

Vid rening av avloppsvatten fås, förutom renare vatten, även slam som biprodukt under reningsprocessen. Slammet har en torrsubstanshalt i storleksordningen 1 % och det första steget vid hanteringen är att avvattna det. Slamavvattningen görs för att minska innehållet av vatten innan det behandlas vidare, till exempel förbränns eller läggs på deponi. Det har då en mindre volym och kräver mindre energi. Vid många mindre reningsverk saknas det utrustning för att utföra slamavvattning och slammet transporteras då till ett större reningsverk för avvattning. Detta innebär transport av stora mängder vatten vilket medför onödiga kostnader och negativ miljöpåverkan som följd. Intern slamavvattning vid mindre reningsverk med traditionella avvattningsmetoder hindras främst av ekonomiska skäl. Syftet med detta projekt har varit att ta reda på om geotextiltuber kan användas för att avvattna slammet vid ett mindre reningsverk istället för att det transporteras till det kommunala reningsverket. Metoden innebär kort att en tub gjord av geotextil används för att filtrera slammet. Under projektet har avvattningstester på slam från Lövsta avloppsreningsverk gjorts för att ta reda på vilken typ av polymer som krävs och vilken dosering som är optimal. Polymeren behövs för att slammet ska flocka sig, så att enbart vattnet passerar genom tuben. Metodens kapacitet har bestämts baserat på hur hög torrsubstanshalt som kan uppnås och rejektvattnet har analyserats för att undersöka om det klarar utsläppskraven som finns. Efter analyser har ett fullskaligt försök påbörjats. Slutligen har en kostnadsanalys gjorts för att avgöra om metoden är ekonomiskt hållbar. Bäst avvattning uppnåddes vid flockning med en katjonisk polyakrylamid med låg laddning och en torrsubstanshalt på 25,5 % uppnåddes, vilket liknar resultat från närliggande kommunala reningsverk. Vid analys av rejektvattnet erhölls lägre halter av BOD 7 och tot-P än de utsläppskrav som finns och metoden har beräknats kostnadsmässigt fördelaktig, Except for clean water, the treatment of wastewater gives rise to a by-product: sludge. The dry matter content of the sludge is around 1% and the first step in handling the sludge is dewatering. By lowering the water content in the sludge, the volume of sludge for further processing is lower and thus less energy-consuming. Many small wastewater treatment plants lack the ability to dewater their sludge. Transporting the sludge to bigger treatment plants for dewatering causes lots of unnecessary transportation of water that cost money and affect the climate in a negative way. Lack of dewatering equipment at small treatment plants is often due to economic reasons. The aim of the project has been to investigate if dewatering of the sludge from the wastewater treatment plant in Lövsta is possible to do by using geotextile tubes. During the project, dewatering tests have been performed to determine the optimal chemical and dosage to flocculate the particles in the sludge. The dewatering capacity was determined by how high dry matter content is was possible to achieve. Analysis of the effluent water was made to see if it meets the requirements needed to release it to the recipient. Finally, a brief economic analysis of the dewatering system has been made. The expected polymer, a cationic polyacrylamide with linear structure and low charge, was the best one for flocculation of the activated sludge from Lövsta. A dry matter content of 25.5% was achieved, a result that is close to the dry matter content the municipal wastewater treatment plant nearby achieves. The levels of phosphorus and BOD 7 in the effluent water meets the requirements and the economic analysis indicates that the method is preferred before transporting it for dewatering elsewhere. An important aspect to consider before recommending this method to other small wastewater treatment plants is if the method is environmentally sustainable.

With the design of experiments (DoE), this study analyses the influence of physical (capillary diameter and pressure drop) and chemical variables (salinity, polymer concentration, and molecular weight) on the mechanical degradation of partially hydrolyzed polyacrylamide-type polymer solutions (HPAM) used in enhanced oil recovery processes. Initially, with the help of a fractional factorial design (2k-p), the variables with the most significant influence on the polymer's mechanical degradation were found. The experimental results of the screening demonstrate that the factors that statistically influence the mechanical degradation are the molecular weight, the diameter of the capillary, and the pressure differential. Subsequently, a regression model was developed to estimate the degradation percentages of HPAM polymer solutions as a function of the significant factors influencing the mechanical degradation of polymer solutions. This model had a 97.85% fit for the predicted values under the experimental conditions. Likewise, through the optimization developed by the Box Behnken response surface methodology, it was determined that the pressure differential was the most influential factor. This variable was followed by the capillary diameter, where less than 50% degradation rates are obtained with low polymer molecular weight (6.5 MDa), pressure differentials less than 500 psi, and diameters of the capillary greater than 0.125 inches., Este estudio evaluó mediante un diseño experimental la influencia de las variables físicas (diámetro de capilar y caída de presión) y químicas (salinidad, concentración de polímero y peso molecular), en la mecánica de soluciones poliméricas tipo poliacrilamidas parcialmente hidrolizadas (HPAM) utilizadas en procesos de recobro mejorado de crudo. Inicialmente, se realizó un diseño factorial fraccionado (2k-p), para determinar las variables con mayor influencia sobre la degradación mecánica del polímero. Los resultados experimentales del cribado indican que los factores que influyen estadísticamente en la degradación mecánica son el peso molecular, el diámetro del capilar y el diferencial de presión. Posteriormente, se desarrolló un modelo de regresión que permite estimar los porcentajes de degradación de soluciones poliméricas HPAM en función de los factores significativos con influencia en la degradación mecánica de las soluciones poliméricas. Este modelo tuvo un ajuste del 97.85% para los valores predichos bajo las condiciones experimentales. Asimismo, mediante la optimización desarrollada por la metodología de superficie de respuesta Box Behnken, se determinó que el diferencial de presión fue el factor más influyente, seguido del diámetro del capilar, donde las tasas de degradación inferiores al 50% se obtienen con polímero de bajo peso molecular (6,5 MDa), diferenciales de presión inferiores a 500 psi y capilares con diámetros superiores a 0,125 pulgadas.

Optimal combination of stem cells and biocompatible support material is a promising strategy for successful tissue engineering. The required differentiation of stem cells is crucial for functionality of engineered tissues and can be regulated by chemical and physical cues. Here we examined how boundary cap neural crest stem cells (bNCSCs) are affected when cultured in the same medium, but on collagen- or laminin-polyacrylamide (PAA) scaffolds of different stiffness (0.5, 1, or similar to 7 kPa). bNCSCs displayed marked differences in their ability to attach, maintain a large cell population and differentiate, depending on scaffold stiffness. These findings show that the design of physical cues is an important parameter to achieve optimal stem cell properties for tissue repair and engineering.

Este estudio evaluó mediante un diseño experimental la influencia de las variables físicas (diámetro de capilar y caída de presión) y químicas (salinidad, concentración de polímero y peso molecular), en la mecánica de soluciones poliméricas tipo poliacrilamidas parcialmente hidrolizadas (HPAM) utilizadas en procesos de recobro mejorado de crudo. Inicialmente, se realizó un diseño factorial fraccionado (2k-p), para determinar las variables con mayor influencia sobre la degradación mecánica del polímero. Los resultados experimentales del cribado indican que los factores que influyen estadísticamente en la degradación mecánica son el peso molecular, el diámetro del capilar y el diferencial de presión. Posteriormente, se desarrolló un modelo de regresión que permite estimar los porcentajes de degradación de soluciones poliméricas HPAM en función de los factores significativos con influencia en la degradación mecánica de las soluciones poliméricas. Este modelo tuvo un ajuste del 97.85% para los valores predichos bajo las condiciones experimentales. Asimismo, mediante la optimización desarrollada por la metodología de superficie de respuesta Box Behnken, se determinó que el diferencial de presión fue el factor más influyente, seguido del diámetro del capilar, donde las tasas de degradación inferiores al 50% se obtienen con polímero de bajo peso molecular (6,5 MDa), diferenciales de presión inferiores a 500 psi y capilares con diámetros superiores a 0,125 pulgadas., With the design of experiments (DoE), this study analyses the influence of physical (capillary diameter and pressure drop) and chemical variables (salinity, polymer concentration, and molecular weight) on the mechanical degradation of partially hydrolyzed polyacrylamide-type polymer solutions (HPAM) used in enhanced oil recovery processes. Initially, with the help of a fractional factorial design (2k-p), the variables with the most significant influence on the polymer's mechanical degradation were found. The experimental results of the screening demonstrate that the factors that statistically influence the mechanical degradation are the molecular weight, the diameter of the capillary, and the pressure differential. Subsequently, a regression model was developed to estimate the degradation percentages of HPAM polymer solutions as a function of the significant factors influencing the mechanical degradation of polymer solutions. This model had a 97.85% fit for the predicted values under the experimental conditions. Likewise, through the optimization developed by the Box Behnken response surface methodology, it was determined that the pressure differential was the most influential factor. This variable was followed by the capillary diameter, where less than 50% degradation rates are obtained with low polymer molecular weight (6.5 MDa), pressure differentials less than 500 psi, and diameters of the capillary greater than 0.125 inches.

Optimal combination of stem cells and biocompatible support material is a promising strategy for successful tissue engineering. The required differentiation of stem cells is crucial for functionality of engineered tissues and can be regulated by chemical and physical cues. Here we examined how boundary cap neural crest stem cells (bNCSCs) are affected when cultured in the same medium, but on collagen- or laminin-polyacrylamide (PAA) scaffolds of different stiffness (0.5, 1, or similar to 7 kPa). bNCSCs displayed marked differences in their ability to attach, maintain a large cell population and differentiate, depending on scaffold stiffness. These findings show that the design of physical cues is an important parameter to achieve optimal stem cell properties for tissue repair and engineering.

Vid rening av avloppsvatten fås, förutom renare vatten, även slam som biprodukt under reningsprocessen. Slammet har en torrsubstanshalt i storleksordningen 1 % och det första steget vid hanteringen är att avvattna det. Slamavvattningen görs för att minska innehållet av vatten innan det behandlas vidare, till exempel förbränns eller läggs på deponi. Det har då en mindre volym och kräver mindre energi. Vid många mindre reningsverk saknas det utrustning för att utföra slamavvattning och slammet transporteras då till ett större reningsverk för avvattning. Detta innebär transport av stora mängder vatten vilket medför onödiga kostnader och negativ miljöpåverkan som följd. Intern slamavvattning vid mindre reningsverk med traditionella avvattningsmetoder hindras främst av ekonomiska skäl. Syftet med detta projekt har varit att ta reda på om geotextiltuber kan användas för att avvattna slammet vid ett mindre reningsverk istället för att det transporteras till det kommunala reningsverket. Metoden innebär kort att en tub gjord av geotextil används för att filtrera slammet. Under projektet har avvattningstester på slam från Lövsta avloppsreningsverk gjorts för att ta reda på vilken typ av polymer som krävs och vilken dosering som är optimal. Polymeren behövs för att slammet ska flocka sig, så att enbart vattnet passerar genom tuben. Metodens kapacitet har bestämts baserat på hur hög torrsubstanshalt som kan uppnås och rejektvattnet har analyserats för att undersöka om det klarar utsläppskraven som finns. Efter analyser har ett fullskaligt försök påbörjats. Slutligen har en kostnadsanalys gjorts för att avgöra om metoden är ekonomiskt hållbar. Bäst avvattning uppnåddes vid flockning med en katjonisk polyakrylamid med låg laddning och en torrsubstanshalt på 25,5 % uppnåddes, vilket liknar resultat från närliggande kommunala reningsverk. Vid analys av rejektvattnet erhölls lägre halter av BOD 7 och tot-P än de utsläppskrav som finns och metoden har beräknats kostnadsmässigt fördelaktig, Except for clean water, the treatment of wastewater gives rise to a by-product: sludge. The dry matter content of the sludge is around 1% and the first step in handling the sludge is dewatering. By lowering the water content in the sludge, the volume of sludge for further processing is lower and thus less energy-consuming. Many small wastewater treatment plants lack the ability to dewater their sludge. Transporting the sludge to bigger treatment plants for dewatering causes lots of unnecessary transportation of water that cost money and affect the climate in a negative way. Lack of dewatering equipment at small treatment plants is often due to economic reasons. The aim of the project has been to investigate if dewatering of the sludge from the wastewater treatment plant in Lövsta is possible to do by using geotextile tubes. During the project, dewatering tests have been performed to determine the optimal chemical and dosage to flocculate the particles in the sludge. The dewatering capacity was determined by how high dry matter content is was possible to achieve. Analysis of the effluent water was made to see if it meets the requirements needed to release it to the recipient. Finally, a brief economic analysis of the dewatering system has been made. The expected polymer, a cationic polyacrylamide with linear structure and low charge, was the best one for flocculation of the activated sludge from Lövsta. A dry matter content of 25.5% was achieved, a result that is close to the dry matter content the municipal wastewater treatment plant nearby achieves. The levels of phosphorus and BOD 7 in the effluent water meets the requirements and the economic analysis indicates that the method is preferred before transporting it for dewatering elsewhere. An important aspect to consider before recommending this method to other small wastewater treatment plants is if the method is environmentally sustainable.

The high content and low removal efficiency of suspended solids (SS) in wastewater derived from shale gas development via hydraulic fracturing has raised advanced treatment problems (e.g., organics removal) and environmental concerns. In this study, two kinds of suspended solids were separated from synthetic flowback wastewater (FWW) after 1 or 14 days of sedimentation. The physicochemical properties, porous structures, surface chemistry, and particle stability of the obtained 1-/14-day solids were characterized. To illustrate the specific roles of SS during radical-based FWW treatment, the removal of di-(2-ethylhexyl) phthalate (DEHP, a typical recalcitrant organic that has been identified in FWW) by a ferrous iron/peroxysulphate (Fe2+/PS) system was examined as a representative case. Results showed that DEHP was simultaneously adsorbed onto the solids and degraded by Fe2+/PS. The removal processes were governed by the phase distribution of DEHP and Fe2+, and the distribution was influenced by interactions between the 1-/14-day solids, Fe2+/PS, and various FWW components. Polyacrylamide (PAM), an anionic surfactant commonly detected in FWW, can attach to the solids and aid in maintaining the structural and compositional integrity of the solids. Due to stronger adsorption with PAM, the 14-day solids retained less DEHP and Fe2+, contributing to enhanced DEHP degradation in the solution phase as compared to the 1-day solids. Thus, sufficient sedimentation is advantageous for the degradation of recalcitrant organic contaminants (e.g., DEHP) in FWW treatment. Moreover, certain FWW components (i.e., PAM and ethylene glycol) can interact with FWW solids, creating a positive synergistic effect on organic removal efficiency.

Optimal combination of stem cells and biocompatible support material is a promising strategy for successful tissue engineering. The required differentiation of stem cells is crucial for functionality of engineered tissues and can be regulated by chemical and physical cues. Here we examined how boundary cap neural crest stem cells (bNCSCs) are affected when cultured in the same medium, but on collagen- or laminin-polyacrylamide (PAA) scaffolds of different stiffness (0.5, 1, or similar to 7 kPa). bNCSCs displayed marked differences in their ability to attach, maintain a large cell population and differentiate, depending on scaffold stiffness. These findings show that the design of physical cues is an important parameter to achieve optimal stem cell properties for tissue repair and engineering.

Dyes are classified as one of the major pollutants of water. They have negative impacts not only on environment but also on human health. In fact, wastewater that contains these harmful substances requires many types of treatments. Therefore, alternative methods and adsorption agents are needed. Herein, we propose to evaluate the decolorization of methylene blue (MB) and methyl orange (MO) as two models of soluble dyes from water using chitin and chitosan-graft-polyacrylamide. Furthermore, the applicability of these biomacromolecules as alternative adsorption agents, their sticking probability and desorption were also examined. Experimental parameters such as dye concentration, contact time, pH solution, adsorbent dosage and temperature were thoroughly examined for the grafted chitosan and chitin. The activation energy (Ea) and the thermodynamic variables (i. e., standard Gibb's free energy (D G0), standard enthalpy (D H0), and standard entropy (D S0)) were determined using the Van't Hoff and Arrhenius equations. The sticking probability (S*) model for MB and MO removal by chitin and the chitosan derivative demonstrated that both dyes were successfully removed under the proposed conditions. Desorption studies of MB and MO showed the reusability of both materials, suggesting their application for removing dyes from aqueous solution.

Dyes are classified as one of the major pollutants of water. They have negative impacts not only on environment but also on human health. In fact, wastewater that contains these harmful substances requires many types of treatments. Therefore, alternative methods and adsorption agents are needed. Herein, we propose to evaluate the decolorization of methylene blue (MB) and methyl orange (MO) as two models of soluble dyes from water using chitin and chitosan-graft-polyacrylamide. Furthermore, the applicability of these biomacromolecules as alternative adsorption agents, their sticking probability and desorption were also examined. Experimental parameters such as dye concentration, contact time, pH solution, adsorbent dosage and temperature were thoroughly examined for the grafted chitosan and chitin. The activation energy (Ea) and the thermodynamic variables (i. e., standard Gibb's free energy (D G0), standard enthalpy (D H0), and standard entropy (D S0)) were determined using the Van't Hoff and Arrhenius equations. The sticking probability (S*) model for MB and MO removal by chitin and the chitosan derivative demonstrated that both dyes were successfully removed under the proposed conditions. Desorption studies of MB and MO showed the reusability of both materials, suggesting their application for removing dyes from aqueous solution.

Effluents from pig slaughter are a source of contamination due to high concentrations of organic matter, nitrogen, phosphorus, fats, total solids and fecal coliforms. This research evaluated the effectiveness of chitosan as a coagulant in the post-treatment of wastewater from the slaughter of pigs, in order to remove the remaining recalcitrant fractions from the biological process in a sequential batch reactor. The tertiary treatment consisted of coagulation, flocculation and sedimentation. The effluent was characterized by the parameters: pH, COD, turbidity, color, total solids (ST), Kjeldahl total nitrogen (NTK), nitrite, nitrate, total phosphorus (PT) and total alkalinity (AT). The treatment was carried out by using the jar test through exploratory runs with doses between 50 and 800 mg/L of chitosan dissolved in acetic acid. The effectiveness of chitosan with conventional coagulants in the treatment of wastewater, such as aluminum sulphate and polyacrylamide, was compared. The experiment was conducted using a completely randomized design with a total of three treatments and three replicates each. The evaluated range of doses of chitosan allowed to obtain percentages of turbidity removal of 83,1%, color of 64,7%, COD of 84,6%, and 78,2% NT for initial values ​​of 15,6 NTU, 26 UC, 865 mg COD/L and 89 mg NT/L, using as optimal dose 700 mg chitosan /L. Significant differences (P≤0,05) were found between chitosan and conventional coagulants in NT removal, with chitosan being the coagulant with the highest removal efficiencies. The treatment with chitosan represents a viable option for the tertiary treatment of the effluents coming from the slaughter of pigs., Resumo Efluentes de abate de suínos são uma fonte de contaminação devido às elevadas concentrações de matéria orgânica, azoto, fósforo, gordura, sólidos totais e coliformes fecais. Nesta pesquisa foi avaliada a eficácia de quitosana como um coagulante nos efluentes porcícolas de pós-tratamento, a fim de remover restantes fracções recalcitrantes de um processo biológico em um reactor de carregamento sequencial. O tratamento terciário consistiu em coagulação, floculação e sedimentação. O efluente tratado foi caracterizado biologicamente pelos parâmetros: pH, DQO, turbidez, cor, sólidos totais (ST), nitrogênio total Kjeldahl (NTK), nitrito, nitrato, fósforo total (PT) e alcalinidade total (AT). O tratamento foi realizado usando jarro teste é executado através exploratórios com doses entre 50 e 1250 mg / L de quitosano dissolvido em ácido acético. A eficácia do quitosano com sulfato de alumínio y poliacrilamida foi comparada. O experimento foi conduzido usando um desenho completamente aleatório com um total de três tratamentos e três repetições. A gama de dose de quitosana avaliada produziu percentagens de remoção de turvação de 83,1% cor 64,7% de CQO de 84,6%, e 78,2% de NT para os valores iniciais de 15,6 NTU, 26 UC Pt-Co, 865 mg CQO / L e 89 mg de NT / L, usando dose óptima de 700 mg de quitosana/L. Diferenças significativas (P≤0,05) entre quitosano e coagulantes convencionais na remoção de NT foram encontrados para ser um tratamento com o coagulante quitosano com as eficiências mais altas de remoção. O tratamento com quitosana representa uma opção viável para o tratamento terciário do efluente opção abate de porco., Resumen Los efluentes provenientes del sacrificio de cerdos son una fuente de contaminación debido a las altas concentraciones de materia orgánica, nitrógeno, fósforo, grasas, sólidos totales y coliformes fecales. En esta investigación se evaluó la efectividad del quitosano como coagulante en el postratamiento de efluentes porcícolas provenientes de un reactor discontinuo secuencial, con el fin de remover las fracciones no biodegradables remanentes del proceso biológico. El tratamiento terciario consistió en la coagulación, floculación y sedimentación. Se caracterizó el efluente tratado biológicamente mediante los siguientes parámetros: pH, DQO, turbidez, color, sólidos totales (ST), nitrógeno total Kjeldahl (NTK), nitrito, nitrato, fosforo total (PT) y alcalinidad total (AT). El tratamiento fisicoquímico se llevó a cabo mediante el uso de la prueba de Jarra a través de corridas exploratorias con dosis entre 50 y 800 mg/L de quitosano disuelto en ácido acético. Se comparó la efectividad del quitosano (700 mg/l) con sulfato de aluminio (430mg/l) y poliacrilamida (90 mg/l), los cuales son utilizados como coagulantes de uso convencional en el tratamiento de aguas residuales. El experimento se condujo mediante un diseño completamente al azar con un total de tres tratamientos (quitosano, sulfato de aluminio y poliacrilamida) y tres repeticiones cada uno. La dosis de quitosano (700 mg/l) permitió obtener porcentajes de reducción de turbidez de 83,1%, color de 64,7%, DQO de 84,6%, y 78,2% de NT para valores iniciales de 15,6 NTU, 26 UC Pt-Co, 865 mg DQO/L y 89 mg NT/L. Se encontraron diferencias significativas (P≤0,05) entre la dosis quitosano (700 mg/l) y los coagulantes convencionales (430 mg/l de sulfato de aluminio y 90 mg/l de poliacrilamida) en la reducción de NT, siendo el tratamiento con quitosano el coagulante con las mayores eficiencias de reducción. El tratamiento con quitosano con una dosis de 700 mg/l representó una opción viable para el tratamiento terciario

Effluents from pig slaughter are a source of contamination due to high concentrations of organic matter, nitrogen, phosphorus, fats, total solids and fecal coliforms. This research evaluated the effectiveness of chitosan as a coagulant in the post-treatment of wastewater from the slaughter of pigs, in order to remove the remaining recalcitrant fractions from the biological process in a sequential batch reactor. The tertiary treatment consisted of coagulation, flocculation and sedimentation. The effluent was characterized by the parameters: pH, COD, turbidity, color, total solids (ST), Kjeldahl total nitrogen (NTK), nitrite, nitrate, total phosphorus (PT) and total alkalinity (AT). The treatment was carried out by using the jar test through exploratory runs with doses between 50 and 800 mg/L of chitosan dissolved in acetic acid. The effectiveness of chitosan with conventional coagulants in the treatment of wastewater, such as aluminum sulphate and polyacrylamide, was compared. The experiment was conducted using a completely randomized design with a total of three treatments and three replicates each. The evaluated range of doses of chitosan allowed to obtain percentages of turbidity removal of 83,1%, color of 64,7%, COD of 84,6%, and 78,2% NT for initial values ​​of 15,6 NTU, 26 UC, 865 mg COD/L and 89 mg NT/L, using as optimal dose 700 mg chitosan /L. Significant differences (P≤0,05) were found between chitosan and conventional coagulants in NT removal, with chitosan being the coagulant with the highest removal efficiencies. The treatment with chitosan represents a viable option for the tertiary treatment of the effluents coming from the slaughter of pigs., Resumo Efluentes de abate de suínos são uma fonte de contaminação devido às elevadas concentrações de matéria orgânica, azoto, fósforo, gordura, sólidos totais e coliformes fecais. Nesta pesquisa foi avaliada a eficácia de quitosana como um coagulante nos efluentes porcícolas de pós-tratamento, a fim de remover restantes fracções recalcitrantes de um processo biológico em um reactor de carregamento sequencial. O tratamento terciário consistiu em coagulação, floculação e sedimentação. O efluente tratado foi caracterizado biologicamente pelos parâmetros: pH, DQO, turbidez, cor, sólidos totais (ST), nitrogênio total Kjeldahl (NTK), nitrito, nitrato, fósforo total (PT) e alcalinidade total (AT). O tratamento foi realizado usando jarro teste é executado através exploratórios com doses entre 50 e 1250 mg / L de quitosano dissolvido em ácido acético. A eficácia do quitosano com sulfato de alumínio y poliacrilamida foi comparada. O experimento foi conduzido usando um desenho completamente aleatório com um total de três tratamentos e três repetições. A gama de dose de quitosana avaliada produziu percentagens de remoção de turvação de 83,1% cor 64,7% de CQO de 84,6%, e 78,2% de NT para os valores iniciais de 15,6 NTU, 26 UC Pt-Co, 865 mg CQO / L e 89 mg de NT / L, usando dose óptima de 700 mg de quitosana/L. Diferenças significativas (P≤0,05) entre quitosano e coagulantes convencionais na remoção de NT foram encontrados para ser um tratamento com o coagulante quitosano com as eficiências mais altas de remoção. O tratamento com quitosana representa uma opção viável para o tratamento terciário do efluente opção abate de porco., Resumen Los efluentes provenientes del sacrificio de cerdos son una fuente de contaminación debido a las altas concentraciones de materia orgánica, nitrógeno, fósforo, grasas, sólidos totales y coliformes fecales. En esta investigación se evaluó la efectividad del quitosano como coagulante en el postratamiento de efluentes porcícolas provenientes de un reactor discontinuo secuencial, con el fin de remover las fracciones no biodegradables remanentes del proceso biológico. El tratamiento terciario consistió en la coagulación, floculación y sedimentación. Se caracterizó el efluente tratado biológicamente mediante los siguientes parámetros: pH, DQO, turbidez, color, sólidos totales (ST), nitrógeno total Kjeldahl (NTK), nitrito, nitrato, fosforo total (PT) y alcalinidad total (AT). El tratamiento fisicoquímico se llevó a cabo mediante el uso de la prueba de Jarra a través de corridas exploratorias con dosis entre 50 y 800 mg/L de quitosano disuelto en ácido acético. Se comparó la efectividad del quitosano (700 mg/l) con sulfato de aluminio (430mg/l) y poliacrilamida (90 mg/l), los cuales son utilizados como coagulantes de uso convencional en el tratamiento de aguas residuales. El experimento se condujo mediante un diseño completamente al azar con un total de tres tratamientos (quitosano, sulfato de aluminio y poliacrilamida) y tres repeticiones cada uno. La dosis de quitosano (700 mg/l) permitió obtener porcentajes de reducción de turbidez de 83,1%, color de 64,7%, DQO de 84,6%, y 78,2% de NT para valores iniciales de 15,6 NTU, 26 UC Pt-Co, 865 mg DQO/L y 89 mg NT/L. Se encontraron diferencias significativas (P≤0,05) entre la dosis quitosano (700 mg/l) y los coagulantes convencionales (430 mg/l de sulfato de aluminio y 90 mg/l de poliacrilamida) en la reducción de NT, siendo el tratamiento con quitosano el coagulante con las mayores eficiencias de reducción. El tratamiento con quitosano con una dosis de 700 mg/l representó una opción viable para el tratamiento terciario

Dyes are classified as one of the major pollutants of water. They have negative impacts not only on environment but also on human health. In fact, wastewater that contains these harmful substances requires many types of treatments. Therefore, alternative methods and adsorption agents are needed. Herein, we propose to evaluate the decolorization of methylene blue (MB) and methyl orange (MO) as two models of soluble dyes from water using chitin and chitosan-graft-polyacrylamide. Furthermore, the applicability of these biomacromolecules as alternative adsorption agents, their sticking probability and desorption were also examined. Experimental parameters such as dye concentration, contact time, pH solution, adsorbent dosage and temperature were thoroughly examined for the grafted chitosan and chitin. The activation energy (Ea) and the thermodynamic variables (i. e., standard Gibb's free energy (D G0), standard enthalpy (D H0), and standard entropy (D S0)) were determined using the Van't Hoff and Arrhenius equations. The sticking probability (S*) model for MB and MO removal by chitin and the chitosan derivative demonstrated that both dyes were successfully removed under the proposed conditions. Desorption studies of MB and MO showed the reusability of both materials, suggesting their application for removing dyes from aqueous solution.

Composites based on interpenetrating networks (IPNs) of cellulose nanofibril (CNF) aerogels and polyacrylamide are prepared and exhibit robust mechanical, water retaining, and re-swelling capacities. Furthermore, their swelling behavior is not affected by an increased ionic strength of the aqueous phase. These unprecedented IPNs combine the water retaining capacity of the polyacrylamide with the mechanical strength provided by the CNF aerogel template. The CNF aerogel/polyacrylamide composites exhibit a compressive stress at break greater than 250% compared with a neat polyacrylamide hydrogel. Furthermore, the composites retain their wet compression properties after drying and re-swelling, whereas the neat polyacrylamide hydrogels fail at a significantly lower stress and strain after drying and re-swelling. These composite materials highlight the potential of CNF aerogels to strengthen the mechanical properties and reduce the number of fracture defects during the drying and re-swelling of a hydrogel. These composites show the potential of being optimized for a plethora of applications, especially in the hygiene field and for biomedical devices., QC 20180529

Climate change gives rise to rapid degradation of rural soils in sloping subtropical and tropical areas and might further threaten environmental sustainability. In this study, we conducted an integrated evaluation of the effects of wood biochar (WB) application mixed with a green waste dreg compost (GWC) on runoff quality, soil losses, and agricultural productivity for a highly weathered tropical soil. A conventional agriculture method, in which soils are treated with anionic polyacrylamide (PAM), was also conducted for comparison. The amounts of runoff and soil loss, and nutrient retention were evaluated a year after WB application. Soil fertility was also investigated through a year pot experiment with rape (Brassica campestris L.) cultivation. Our results showed that the WB application not only effectively increased soil pH, soil organic carbon (SOC) and exchangeable K+ but also increased the production of rape plants. Significant reduction of runoff and the increases of inorganic nitrogen (IN) and total phosphorus (TP) were found in the WB-treated soil. Compared to the control, the co-application of WB and GWC, particularly for the WB at 4%, decreased runoff by 16.8%, soil loss by 25%, and IN loss (via runoff) by 41.8%. Meanwhile, compared to the control and PAM treatments, the co-application of WB and GWC improved soil acidity and the contents of SOC, IN, TP, and exchangeable K+. The co-application of WB and GWC could be an alternative agricultural strategy to obtain benefits to agricultural productivity and environmental sustainability. © 2017 Elsevier B.V.

Submicron- and micron-scale structures of composite hydrogels based on bacterial cellulose (BC) and polyacrylamide (PAAm) were studied by spin-echo small-angle neutron scattering (SESANS) and cryo-scanning electron microscopy (cryo-SEM). These hydrogels possessing the structure of interpenetrating polymer network were synthesized via free-radical polymerization of acrylamide carried out in the pellicle of BC swollen in the reaction solution. No neutron scattering was observed for the samples swollen in heavy water to the equilibrium state, but the SESANS signal appeared when TbCl3 salt was added to the solvent. It is the unusual effect, which may be very helpful for SESANS studying of other hydrogel systems. The SESANS dependences obtained for these samples revealed the anisotropy of mesostructure for the hydrogels under investigation. Density inhomogeneities on the characteristic scale of 11.5 ± 0.5 μm were detected in one fixed orientation of the sample, i.e., with the growth plane of BC parallel to the plane formed by the neutron beam and the spin-echo length. The uniaxial anisotropy revealed agrees with a recently proposed model, which attributes this behavior to the existence of tunnel-like oriented structures inside BC. The evidence of such type of mesostructure anisotropy of BC and BC-PAAm hydrogels was obtained by using the cryo-SEM method., Accepted Author Manuscript, RST/Neutron and Positron Methods in Materials, Technici Pool

Theoretical consideration of the factors of the stability of metallic iron magnetic nanoparticles (MNPs) in water suspensions was done using extended DLVO (Derjaguin-Landau-Verwey-Overbeek) approach based on the balance among Van der Waals, electrostatic, magnetic and steric interactions. Magnetic and steric interactions dominate over other in suspensions of Fe MNPs. To test the theory Fe MNPs with average diameter 84 nm were synthesized by electrical explosion of wire and encapsulated by polyacrylamide in water suspension to provide steric repulsion. It was shown that encapsulation resulted in the efficient diminishing of the aggregation of metallic iron MNPs in water.

UV-C induced surface grafting has been performed on bio-degradable/bio-compatible polylactide (PLA) films, and poly(lactide-co-glycidyl methacrylate) and partially crosslinked poly(lactide-co-glycidyl methacrylate), P(LA-co-GMA) copolymer powders by employing a hydrophilic vinyl monomer, acrylamide (Am), and a crosslinker, N,Nˈ-methylene bisacrylamide (MBAm) to form a partial crosslinked structure among PAm graft chains. Three separate photo-initiators (with/without coinitiator, and thermal initiator to speed up photo-grafting reaction); riboflavin (RF) photo-initiator/ammonium persulfate (APS) thermal-initiator/N,N,Nˈ,Nˈ-tetramethylethylenediamine co-initiator (TEMED), camphorquinone (CQ) photo-initiator/N,Nˈ-dimethylaminoethyl methacrylate (DMAEMA) co-initiator, and benzophenone (BP) photo-initiator are deployed in methanol solutions of monomer-crosslinker, independently. The surface-grafted poly(lactide-graft-acrylamide-co-N,Nˈ-methylene bisacrylamide) copolymer films, P(LA-g-Am-co-MBAm) and poly(lactide-co-glycidyl methacrylate-graft-acrylamide-co-N,Nˈ-methylene bisacrylamide) copolymers particles, P(LA-co-GMA-g-Am-co-MBAm) possess a combination of unique properties of biodegradable PLA, PAm, and PGMA (only in powder samples) polymers. The success of the surface photo-grafting process on both films and powders was verified by FTIR (transmission and/or ATR mode) and 1H NMR spectroscopy. The characteristics FTIR absorption bands at around 1680 and 1599 cm−1 in the grafted copolymers’ spectra, accounted for amide I and amide II bands, respectively, confirm the presence of PAm as P(Am-co-MBAm) graft chains. Two characteristics 1H NMR signals of PAm appear at around 2.0-2.1 and 1.5-1.6 ppm (overlap with PLA methine proton) in the grafted copolymer spectra, further ensuring the existence of polyacrylamide. The evidence of grafting reaction on the PLA films is also confirmed by XPS analysis. Physicochemical changes of the blank PLA and grafted PLA films are evaluated i

In this study, the irrigation water infiltration rate (IR) is defined by input variables in linguistic terms using a fuzzy-logic approach. A fuzzy-logic model was developed using data collected from published data. The model was trained with three fuzzy membership functions: triangular (‘trimf’), trapezoid (‘trapmf’), and pi (‘pimf’). The fuzzy system considered the number of irrigation events, applied water depth, polyacrylamide application rate, water application time, water electrical conductivity, soil surface slope, and soil texture components as input variables. The inputs were classified in terms of low, medium, and high levels. The output variable (i.e., IR) was rated in terms of five levels: very low, low, medium, high, and very high. Using statistical analysis, the values of IR resulting from the developed fuzzy-logic model were compared with the observations from the experiments. The results confirm that the agreement between the observations and predictive results was acceptable, except for fuzzy ‘trimf’. The coefficient of determination provided the greatest value when using the ‘trapmf’ and ‘pimf’, with the value estimated for the ‘pimf’ slightly higher than that of ‘trapmf’. Based on the results that were obtained, irrigation managers can use the fuzzy-logic approach to modify their field practices during the growing season to improve on-farm water management.

UV-C induced surface grafting has been performed on bio-degradable/bio-compatible polylactide (PLA) films, and poly(lactide-co-glycidyl methacrylate) and partially crosslinked poly(lactide-co-glycidyl methacrylate), P(LA-co-GMA) copolymer powders by employing a hydrophilic vinyl monomer, acrylamide (Am), and a crosslinker, N,Nˈ-methylene bisacrylamide (MBAm) to form a partial crosslinked structure among PAm graft chains. Three separate photo-initiators (with/without coinitiator, and thermal initiator to speed up photo-grafting reaction); riboflavin (RF) photo-initiator/ammonium persulfate (APS) thermal-initiator/N,N,Nˈ,Nˈ-tetramethylethylenediamine co-initiator (TEMED), camphorquinone (CQ) photo-initiator/N,Nˈ-dimethylaminoethyl methacrylate (DMAEMA) co-initiator, and benzophenone (BP) photo-initiator are deployed in methanol solutions of monomer-crosslinker, independently. The surface-grafted poly(lactide-graft-acrylamide-co-N,Nˈ-methylene bisacrylamide) copolymer films, P(LA-g-Am-co-MBAm) and poly(lactide-co-glycidyl methacrylate-graft-acrylamide-co-N,Nˈ-methylene bisacrylamide) copolymers particles, P(LA-co-GMA-g-Am-co-MBAm) possess a combination of unique properties of biodegradable PLA, PAm, and PGMA (only in powder samples) polymers. The success of the surface photo-grafting process on both films and powders was verified by FTIR (transmission and/or ATR mode) and 1H NMR spectroscopy. The characteristics FTIR absorption bands at around 1680 and 1599 cm−1 in the grafted copolymers’ spectra, accounted for amide I and amide II bands, respectively, confirm the presence of PAm as P(Am-co-MBAm) graft chains. Two characteristics 1H NMR signals of PAm appear at around 2.0-2.1 and 1.5-1.6 ppm (overlap with PLA methine proton) in the grafted copolymer spectra, further ensuring the existence of polyacrylamide. The evidence of grafting reaction on the PLA films is also confirmed by XPS analysis. Physicochemical changes of the blank PLA and grafted PLA films are evaluated i

UV-C induced surface grafting has been performed on bio-degradable/bio-compatible polylactide (PLA) films, and poly(lactide-co-glycidyl methacrylate) and partially crosslinked poly(lactide-co-glycidyl methacrylate), P(LA-co-GMA) copolymer powders by employing a hydrophilic vinyl monomer, acrylamide (Am), and a crosslinker, N,Nˈ-methylene bisacrylamide (MBAm) to form a partial crosslinked structure among PAm graft chains. Three separate photo-initiators (with/without coinitiator, and thermal initiator to speed up photo-grafting reaction); riboflavin (RF) photo-initiator/ammonium persulfate (APS) thermal-initiator/N,N,Nˈ,Nˈ-tetramethylethylenediamine co-initiator (TEMED), camphorquinone (CQ) photo-initiator/N,Nˈ-dimethylaminoethyl methacrylate (DMAEMA) co-initiator, and benzophenone (BP) photo-initiator are deployed in methanol solutions of monomer-crosslinker, independently. The surface-grafted poly(lactide-graft-acrylamide-co-N,Nˈ-methylene bisacrylamide) copolymer films, P(LA-g-Am-co-MBAm) and poly(lactide-co-glycidyl methacrylate-graft-acrylamide-co-N,Nˈ-methylene bisacrylamide) copolymers particles, P(LA-co-GMA-g-Am-co-MBAm) possess a combination of unique properties of biodegradable PLA, PAm, and PGMA (only in powder samples) polymers. The success of the surface photo-grafting process on both films and powders was verified by FTIR (transmission and/or ATR mode) and 1H NMR spectroscopy. The characteristics FTIR absorption bands at around 1680 and 1599 cm−1 in the grafted copolymers’ spectra, accounted for amide I and amide II bands, respectively, confirm the presence of PAm as P(Am-co-MBAm) graft chains. Two characteristics 1H NMR signals of PAm appear at around 2.0-2.1 and 1.5-1.6 ppm (overlap with PLA methine proton) in the grafted copolymer spectra, further ensuring the existence of polyacrylamide. The evidence of grafting reaction on the PLA films is also confirmed by XPS analysis. Physicochemical changes of the blank PLA and grafted PLA films are evaluated i

UV-C induced surface grafting has been performed on bio-degradable/bio-compatible polylactide (PLA) films, and poly(lactide-co-glycidyl methacrylate) and partially crosslinked poly(lactide-co-glycidyl methacrylate), P(LA-co-GMA) copolymer powders by employing a hydrophilic vinyl monomer, acrylamide (Am), and a crosslinker, N,Nˈ-methylene bisacrylamide (MBAm) to form a partial crosslinked structure among PAm graft chains. Three separate photo-initiators (with/without coinitiator, and thermal initiator to speed up photo-grafting reaction); riboflavin (RF) photo-initiator/ammonium persulfate (APS) thermal-initiator/N,N,Nˈ,Nˈ-tetramethylethylenediamine co-initiator (TEMED), camphorquinone (CQ) photo-initiator/N,Nˈ-dimethylaminoethyl methacrylate (DMAEMA) co-initiator, and benzophenone (BP) photo-initiator are deployed in methanol solutions of monomer-crosslinker, independently. The surface-grafted poly(lactide-graft-acrylamide-co-N,Nˈ-methylene bisacrylamide) copolymer films, P(LA-g-Am-co-MBAm) and poly(lactide-co-glycidyl methacrylate-graft-acrylamide-co-N,Nˈ-methylene bisacrylamide) copolymers particles, P(LA-co-GMA-g-Am-co-MBAm) possess a combination of unique properties of biodegradable PLA, PAm, and PGMA (only in powder samples) polymers. The success of the surface photo-grafting process on both films and powders was verified by FTIR (transmission and/or ATR mode) and 1H NMR spectroscopy. The characteristics FTIR absorption bands at around 1680 and 1599 cm−1 in the grafted copolymers’ spectra, accounted for amide I and amide II bands, respectively, confirm the presence of PAm as P(Am-co-MBAm) graft chains. Two characteristics 1H NMR signals of PAm appear at around 2.0-2.1 and 1.5-1.6 ppm (overlap with PLA methine proton) in the grafted copolymer spectra, further ensuring the existence of polyacrylamide. The evidence of grafting reaction on the PLA films is also confirmed by XPS analysis. Physicochemical changes of the blank PLA and grafted PLA films are evaluated i

In this study, the irrigation water infiltration rate (IR) is defined by input variables in linguistic terms using a fuzzy-logic approach. A fuzzy-logic model was developed using data collected from published data. The model was trained with three fuzzy membership functions: triangular (‘trimf’), trapezoid (‘trapmf’), and pi (‘pimf’). The fuzzy system considered the number of irrigation events, applied water depth, polyacrylamide application rate, water application time, water electrical conductivity, soil surface slope, and soil texture components as input variables. The inputs were classified in terms of low, medium, and high levels. The output variable (i.e., IR) was rated in terms of five levels: very low, low, medium, high, and very high. Using statistical analysis, the values of IR resulting from the developed fuzzy-logic model were compared with the observations from the experiments. The results confirm that the agreement between the observations and predictive results was acceptable, except for fuzzy ‘trimf’. The coefficient of determination provided the greatest value when using the ‘trapmf’ and ‘pimf’, with the value estimated for the ‘pimf’ slightly higher than that of ‘trapmf’. Based on the results that were obtained, irrigation managers can use the fuzzy-logic approach to modify their field practices during the growing season to improve on-farm water management.

UV-C induced surface grafting has been performed on bio-degradable/bio-compatible polylactide (PLA) films, and poly(lactide-co-glycidyl methacrylate) and partially crosslinked poly(lactide-co-glycidyl methacrylate), P(LA-co-GMA) copolymer powders by employing a hydrophilic vinyl monomer, acrylamide (Am), and a crosslinker, N,Nˈ-methylene bisacrylamide (MBAm) to form a partial crosslinked structure among PAm graft chains. Three separate photo-initiators (with/without coinitiator, and thermal initiator to speed up photo-grafting reaction); riboflavin (RF) photo-initiator/ammonium persulfate (APS) thermal-initiator/N,N,Nˈ,Nˈ-tetramethylethylenediamine co-initiator (TEMED), camphorquinone (CQ) photo-initiator/N,Nˈ-dimethylaminoethyl methacrylate (DMAEMA) co-initiator, and benzophenone (BP) photo-initiator are deployed in methanol solutions of monomer-crosslinker, independently. The surface-grafted poly(lactide-graft-acrylamide-co-N,Nˈ-methylene bisacrylamide) copolymer films, P(LA-g-Am-co-MBAm) and poly(lactide-co-glycidyl methacrylate-graft-acrylamide-co-N,Nˈ-methylene bisacrylamide) copolymers particles, P(LA-co-GMA-g-Am-co-MBAm) possess a combination of unique properties of biodegradable PLA, PAm, and PGMA (only in powder samples) polymers. The success of the surface photo-grafting process on both films and powders was verified by FTIR (transmission and/or ATR mode) and 1H NMR spectroscopy. The characteristics FTIR absorption bands at around 1680 and 1599 cm−1 in the grafted copolymers’ spectra, accounted for amide I and amide II bands, respectively, confirm the presence of PAm as P(Am-co-MBAm) graft chains. Two characteristics 1H NMR signals of PAm appear at around 2.0-2.1 and 1.5-1.6 ppm (overlap with PLA methine proton) in the grafted copolymer spectra, further ensuring the existence of polyacrylamide. The evidence of grafting reaction on the PLA films is also confirmed by XPS analysis. Physicochemical changes of the blank PLA and grafted PLA films are evaluated i

The advent of next generation sequencing (NGS) has fundamentally changed genetics research. Where researchers were once focused on sequencing the genome of a species, they now can sequence the genome of a particular tumor or even a single cell. NGS has also made it cost effective to sequence the RNA transcripts found within a cell, a collection of data known as the transcriptome. Unfortunately, current protocols for sequencing the genome and the transcriptome are incompatible. This leaves researchers with a choice: for a given sample you can examine either the DNA or the RNA. The work presented here makes it so that researchers no longer have to make this choice. This dissertation describes the development of a new protocol, known as Gel-Seq, that makes it possible to sequence both DNA and RNA from as few as 400 cells. This technology will allow researchers to directly examine the ways that changes in the genome impact the transcriptome. At the heart of the Gel-Seq protocol is the physical separation of DNA from RNA. This separation is achieved electrophoretically using a newly designed combination of polyacrylamide membranes that take advantage of the size differences between these molecules.Two different device options were developed as a part of the Gel-Seq protocol. One device, designed for rapid adoption, was fabricated using standard equipment found inside of a biology laboratory. The second device, designed for separating low input samples, was fabricated using newly developed micro-scale fabrication techniques. In addition to the development of these physical devices, a biological protocol was developed to generate genome and transcriptome data using these devices. In order to validate this technology, a cell line with a stable genome and transcriptome was used. Comparing the Gel-Seq protocol to standard protocols, the results showed a high correlation for both the genome (R = 0.88) and transcriptome (R = 0.96) data. This supports the conclusion that the dev