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Made available in DSpace on 2022-05-01T11:54:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 Soil tillage is a high-cost operation in the replanting of sugarcane fields. Thus, measures to reduce this cost are desirable, provided that they promote good physical conditions for sugarcane development. The objective of this study was to evaluate the effect of chiseling in total area and in the planting row on the physical attributes of Oxisol and Ultisol after soil tillage and after sugarcane planting. The experimental design was in large and uniform plots, with two treatments and ten replicates. The Oxisol and Ultisol had clay contents of 590 and 168 g kg−1 in the 0.00–0.40 cm layer. Treatments consisted of soil tillage with chiseling in the planting row and with chiseling in total area. After soil chiseling and after planting, undisturbed soil samples were collected in each experimental plot, in three layers (0.00–0.10; 0.10–0.20 and 0.20–0.40 m) and at two sampling sites (row and interrow). In both soils, chiseling in total area was efficient to reduce soil density and increase macroporosity in sugarcane interrows, compared to chiseling in the row. The values of the physical attributes of the soils evaluated, in rows and interrows, were similar in the areas with chiseling in total area and row chiseling after sugarcane planting. Changes in Oxisol and Ultisol structure due to chiseling did not persist after sugarcane planting. The soil under row chiseling system has physical quality similar to that of the soil under total area chiseling system, regardless of texture. School of Agricultural and Veterinarian Sciences São Paulo State University (Unesp) School of Agricultural and Veterinarian Sciences São Paulo State University (Unesp)

Polymer cryogels are very promising for producing functional materials. Their porous structure makes them indispensable for some areas of medicine, catalysis, and biotechnology. In this review we focused on methods for producing cryogels based on biopolymers, interpolyelectrolyte complexes of biopolymers, and composite cryogels based on them. First, the properties of cryogels and brief theoretical information about the production of cryogels based on biopolymers were considered. The second section summarizes the latest advances in the production of cryogels based on complexes of biopolymers and composite cryogels. The features of the synthesis and the factors affecting the final properties of materials were considered. In the final part the fields of application of cryogels of the considered types in biotechnology, catalysis and medicine were studied in detail. In biotechnology cryogels are used to immobilize molecules and cells, as a basis for cell growth, and as chromatographic materials for cell separation. In catalysis cryogels are used as a matrix for the immobilization of metal nanoparticles, as well as for the immobilization of enzymes. Biocompatible cryogels and their composites are widely used in medicine for bone and cartilage tissue regeneration, drug delivery, providing a long-term profile of drug release in the body.

The paper describes the impact and importance of preprocessing methods of fabric image for detection of inter-thread pores (ITP), which is a new method of individual ITP identification. The aim of this experiment is to identify precisely every individual ITP of fabric structure by using optimal preprocessing algorithm for further quantitative, morphometric structural analysis of specialized fabrics (barriers, industrial filters, composites, others) in context of air permeability, flow resistance, UV radiation, viruses penetration, thermal comfort by estimation fabric porosity, especially macroporosity parameters and cover factor. The correct identification of individual ITP depends on the acquisition method and the preprocessing algorithm. It was conducted by analyzing the adaptation of digital image preprocessing methods for two structures of plain weave fabric in two magnification zooms, 1.25 and 0.8. Preprocessing operations were performed in the area of spatial operations of the image. The optimal preprocessing algorithm includes low-pass filtering, histogram equalization, nonlinear filtering, thresholding, and morphological operation. This algorithm was selected based on the factors developed by the author (ITP detection, RID factor—a difference between the real and model ITP areas) which rely on the ITP size, shape, and location. The graphic view of the ITP contour position on the fabric image is a verification element in the optimal preprocessing algorithm. The presented results of the air permeability of two different plain weave structures confirm the need to optimize the algorithm of pre-image processing methods to precisely detect each individual ITP in the fabric image.

International audience; A novel particle-based model is proposed to generate synthetic yet representative 3D microstructures of typical SOC electrodes. The model steps can be related to the real electrode manufacturing routes, classically via powders processing, making it a practical tool for electrodes design optimization. The representativeness of the synthetic microstructures is checked on several two-phase (LSCF, LSC) and three-phase (Ni-YSZ) electrodes reconstructed by synchrotron X-ray and FIB-SEM tomography. The validation shows a very good agreement between the real and synthetic media in terms of metric, topological and physical properties. Furthermore, the model is adapted to simulate the microstructure of a typical Ni-YSZ current collecting layer by taking into account a bimodal pore-size-distribution. In this objective, the macro-pores resulting from the burning-off of specific pore-formers are morphologically separated in the reconstruction from the micro-porosity network. Finally, the geometrical features of the macro-pores are meticulously characterized and successfully emulated by using parametric ellipsoids.

Increased soil compaction resulting from livestock treading and use of heavy machinery is a major environmental hazard often linked to degradation of the soil ecosystem and economic services. However, there is a weak quantitative understanding of the spatial and temporal extent of soil compaction and how it modifies soil properties and associated functions. To address this challenge, we developed a framework for systematic modelling soil compaction caused by grazing animals. We considered random movement of livestock in a confined field to describe the spatial variation in the soil that is discretized in square cells with given properties. We then used a rheology model based on Bingham’s law to infer compaction-induced changes in soil bulk density and porosity. An associated reduction of saturated hydraulic conductivity is obtained from soil porosity predictions by empirically accounting for macroporosity reduction using a dual-porosity permeability model. This model is coupled with an empirical model of soil structure recovery to account for biological activity (i.e., earthworms and roots). The modelling framework effectively captures primary effects of soil compaction on key soil properties despite lack of explicit consideration of complex effects of compaction such as redistribution of pore sizes and changes in pore connectivity. We tested the model using bulk density, macroporosity and saturated hydraulic conductivity data from a grazing study at the Tussock Creek experimental platform in New Zealand. Data were successfully reproduced by the model. Compaction and recovery trends can be interpreted in terms of model properties associated with management, soil texture and environmental conditions. If data are available for calibration of such properties, the model could be used in agro-ecosystem modelling applications to assess the environmental impacts (such as surface runoff and green-house gas emissions) of livestock-grazing systems and inform management strategies for ameliorating these.

Soil hydraulic properties and pore continuity are important parameters of soil quality and may differ among tillage systems, crop rotations, and change over time. However, there are some contrasting results, depending on soil type, climate and cultivation history on the spatial and temporal variations. The objective of this study was to determine spatio-temporal dynamics of soil hydraulic properties and pore characteristics (i.e., pore volume, effective porosity, and continuity) on a silt loam long-term tillage field experiment, in Agramunt, NE Spain, during two cropping years. Undisturbed soil samples were used to determine soil water retention, θ(Ψ), and soil hydraulic conductivity, K(Ψ), curves in two different tillage systems (intensive tillage, IT vs no-tillage, NT), two crop sequences (short fallow-maize, FM vs legume-maize, LM) and two positions (within the row of crops, W-row vs between the rows of crops, B-row). The results revealed that LM had greater specific hydraulic conductivity, Kpc in its macroporosity (>1000 µm) than FM due to greater number of effective pores, Npc and effective porosity, εpc. Soil water content, θ was greater under IT than under NT at higher soil water matric potential, Ψ (≥-3 cm H2O), whilst the opposite was observed at lower Ψ (≤ − 50 cm H2O). Long-term NT showed greater hydraulic conductivity, K at higher Ψ (≥ − 10 cm H2O) than IT, and no difference at lower Ψ. Although IT had greater pore volume, ϕpc than NT in the macroporosity and coarse mesoporosity (1000–60 µm) pore size classes, NT had two times greater Kpc than IT due to increased Npc, εpc, and pore continuity, Cwpc. K(Ψ) and pore characteristics showed spatial variations (W-row vs B-row). W-row had significantly greater K at higher Ψ (≥ − 3 cm H2O) than B-row. Temporal dynamics of soil hydraulic properties and pore characteristics were not evident under IT during crop succession. This study shows that LM increases specific hydraulic conductivity of soil macroporosity by increasing the number of effective macropores and the effective porosity. In a Mediterranean climate, this may improve the hydrological functions of agricultural soil and associated crop yield. Further, long-term NT formed a stable number of effective macropores and coarse mesopores, and showed a greater pore continuity in coarse and fine mesopores, resulting in improved soil water flux. The authors thank the support given by Dr. Stefan Fenner, the visiting Ph.D. candidate Mehrdad Soranj, Prof. Concha Ramos, the field and laboratory technicians Carlos Cortés and Silvia Martí, and the farmer Xavier Penella. The authors gratefully acknowledge support for this research from the Research Spanish Agency (DISOSMED Project - AGL2017-84529-C3-R). Rasendra Talukder also sincerely acknowledges the fund provided by University of Lleida to support its PhD fellowship. Daniel Plaza-Bonilla is Ramón y Cajal fellow (RYC-2018-024536-I) co-funded by MICIN/AEI/10.13039/501100011033 and European Social Fund.

Volumetric muscle loss (VML), characterized by an irreversible loss of skeletal muscle due to trauma or surgery, is accompanied by severe functional impairment and long-term disability. Tissue engineering strategies combining stem cells and biomaterials hold great promise for skeletal muscle regeneration. However, scaffolds, including decellularized extracellular matrix (dECM), hydrogels, and electrospun fibers, used for VML applications generally lack macroporosity. As a result, the scaffolds used typically delay host cell infiltration, transplanted cell proliferation, and new tissue formation. To overcome these limitations, we engineered a macroporous dECM-methacrylate (dECM-MA) hydrogel, which we will refer to as a dECM-MA sponge, and investigated its therapeutic potential in vivo. Our results demonstrate that dECM-MA sponges promoted early cellularization, endothelialization, and establishment of a pro-regenerative immune microenvironment in a mouse VML model. In addition, dECM-MA sponges enhanced the proliferation of transplanted primary muscle stem cells, muscle tissue regeneration, and functional recovery four weeks after implantation. Finally, we investigated the scale-up potential of our scaffolds using a rat VML model and found that dECM-MA sponges significantly improved transplanted cell proliferation and muscle regeneration compared to conventional dECM scaffolds. Together, these results validate macroporous hydrogels as novel scaffolds for VML treatment and skeletal muscle regeneration.

Cryogelation is a developing technique for the production of polysaccharide materials for biomedical applications. The formation of a macroporous structure during the freeze-drying of polysaccharide solutions creates biomaterials suitable for tissue engineering. Due to its availability, biocompatibility, biodegradability, and non-toxicity, chitin is a promising natural polysaccharide for the production of porous materials for tissue engineering, however, its use is limited due to the difficulty of dissolving it. This work describes the preparation of cryogels using phosphoric acid as the solvent. Compared to typical chitin solvents phosphoric acid can be easily removed from the product and recovered. The effects of chitin dissolution conditions on the structure and properties of cryogels were studied. Lightweight (ρ 0.025–0.059 g/cm3), highly porous (96–98%) chitin cryogels with various heterogeneous morphology were produced at a dissolution temperature of 20 ± 3 °C, a chitin concentration of 3–15%, and a dissolution time of 6–25 h. The crystallinity of the chitin and chitin cryogels was evaluated by 13C CP-MAS NMR spectroscopy and X-ray diffractometry. Using FTIR spectroscopy, no phosphoric acid esters were found in the chitin cryogels. The cryogels had compressive modulus E values from 118–345 kPa and specific surface areas of 0.3–0.7 m2/g. The results indicate that chitin cryogels can be promising biomaterials for tissue engineering.

The effects of oxidation in the thermomechanical response of porous titanium diboride have been investigated. An in-house quasi-static material point method tool was used to perform two -dimensional plane strain simulations on unoxidized hexagonal representative volume elements (RVEs) with macroporosity volume fractions of 10%, 40% and 70% to establish a baseline for the response due to geometric effects. Compressive strains of up to 30% were applied at room temperature. The 10% and 40% RVEs showed shear banding and subsequent shear failure of the inter-pore struts, while shear banding in 70% RVE weakened the struts, which lead to buckling failure. A snapshot oxidation model was then applied to the hexagonal RVEs in place of a transient, diffusion-based oxidation solver. Compressive strain simulations were performed on RVEs with oxide layers ranging from 5 to 50 μm. In RVEs with porosity of 40% or higher, oxide percolation in the struts reduced the effective elastic modulus and compressive strength, though further oxidation beyond the percolation point did not have a significant impact. Ramped and cyclic thermal loads were applied and the damage due to thermal expansion coefficient mismatch at the oxide-substrate interface decreased as the oxide layer was increased. Finally, the snapshot oxidation modeling approach was applied to large porous RVEs derived from micro-computed tomography images of titanium diboride foam. The effective elastic modulus decreased by 47% when the 5 μm layer was applied due to many thin, flexible struts becoming fully oxidized. Subsequent oxidation did not have a significant impact on the thermomechanical response. Master of Science Thermal loading experienced by hypersonic flight vehicles has posed significant design challenges in the development of platforms for military and re-entry applications. The advent of hypersonic strike weapons and waveriders has led to an interest in utilizing ceramics with melting points above 3000°C, called ultra-high temperature ceramics (UHTCs), that offer improved resistance to high-temperature oxidation. Beyond load-carrying applications, UHTCs imbued with macroscale porosity have been introduced as candidates for providing thermal insulation of sensitive on-board components. This thesis presents a first pass at modeling the coupled effects of oxidation and continuum damage in the thermomechanical response of such materials. Using an in-house material point method tool, two-dimensional compressive strain simulations were performed on hexagonal representative volume elements (RVEs) of titanium diboride foam with varying levels of macroporosity, along with large porous RVEs derived from micro-computed tomography images of titanium diboride foam. A snapshot oxidation model was applied to these RVEs in place of a transient, diffusion-based oxidation solver, then simulations with applied compressive strains of up to 30% were performed on RVEs with oxide layers ranging from 5 to 50 μm. Ramped and cyclic thermal loads were applied to explore the effects of thermal expansion mismatch between the substrate and oxide phases. The oxide layers were shown to reduce the effective stiffness, compressive strength, and thermal conductivity of the RVEs, with the oxidation state of the inter-pore struts having a large impact on the overall material response.

Contains fulltext : 229128.pdf (Publisher’s version ) (Open Access) Synthetic calcium phosphate (CaP) ceramics represent the most widely used biomaterials for bone regenerative treatments due to their biological performance that is characterized by bioactivity and osteoconductive properties. From a clinical perspective, injectable CaP cements (CPCs) are highly appealing, as CPCs can be applied using minimally invasive surgery and can be molded to optimally fill irregular bone defects. Such CPCs are prepared from a powder and a liquid component, which upon mixing form a paste that can be injected into a bone defect and hardens in situ within an appropriate clinical time window. However, a major drawback of CPCs is their poor degradability. Ideally, CPCs should degrade at a suitable pace to allow for concomitant new bone to form. To overcome this shortcoming, control over CPC degradation has been explored using multiple approaches that introduce macroporosity within CPCs. This strategy enables faster degradation of CPC by increasing the surface area available to interact with the biological surroundings, leading to accelerated new bone formation. For a comprehensive overview of the path to degradable CPCs, this review presents the experimental procedures followed for their development with specific emphasis on (bio)material properties and biological performance in pre-clinical bone defect models.

9 figures, 1 table.-- Supplementary material available., Carbon nanotubes (CNTs), graphene aerogels (GAs), and their hybrid (CNT-GA) prepared by hydrothermal treatment were tested in the electrocatalytic oxygen reduction reaction (ORR). The importance of porous structure derived from the combination of mesoporosity coming from CNTs with macroporosity stemming from GAs was evidenced because the hybrid carbon material exhibited synergistic performance in terms of kinetic current and onset potential. Different electrocatalysts were prepared based on these hybrids doped with nitrogen using different precursors and also supporting Fe nanoparticles. N-doped carbon hybrids showed higher electrocatalytic activity than their undoped counterparts. Nevertheless, both doped and undoped materials provided a mixed two and four electron reduction. On the other hand, the addition of a Fe precursor and phenanthroline to the CNT-GA allowed preparing an N-doped hybrid containing Fe nanoparticles which favored the 4-electron oxygen reduction to water, thus being an excellent candidate as a structured cathode in fuel cells., This research was funded by Spanish Ministry MICINN/AI under Projects PID2019-104272RB-C51/AEI/10.13039/501100011033, PID2020-119160RB-C21 and Gobierno de Aragon (Grupo reconocido DGA T03_20R,) are gratefully acknowledged.

Macroporous silica ceramic was obtained using clay and diatomite. Boric acid as a low-cost additive in the amount of 1 wt% was used. These porous materials were obtained at low forming pressure (40-80 MPa) and lower sintering temperature (850-1300 ?C) for 4h in air. The influence of boric acid, forming pressure, and sintering temperature on the microstructure, porosity parameters, and mechanical properties of obtained porous monoliths were investigated. As-received and the modified samples were characterized by X-ray diffraction, FTIR, SEM, and mercury porosimetry measurements. As for modified clay and diatomite, they were pressed at 60 MPa and then sintered at 1150 ?C, obtaining porosities of about 10 % and 60 %, respectively. Both of the analyzed samples had the pore diameter in the range of macroporous materials. The pore diameters of clay samples are ranging from 0.1-10 ?m, whereas the pore diameter of diatomite samples was slightly lower with values ranging from 0.05-5 ?m. Modified diatomite samples have a lower Young modulus in comparison to modified clay samples.

Rubble pile asteroids such as (101955) Bennu, the target of NASA’s OSIRIS-REx mission, have large bulk porosities, which are believed to result from void spaces in between the constituent boulders (macroporosity) as well as void spaces within the boulders themselves (microporosity). Instead of estimating both quantities based on comparison with analog meteorites, we use semi-empirical models for the macroporosity of multi-component mixtures (Zou+ 2011, Grott+ 2020) to determine Bennu's macroporosity based on the observed size-frequency distribution of boulders on the surface; global bulk porosity of Bennu was determined from the observed gravity field and shape. The employed size-frequency distribution covers the size range from 0.2 m to 95 m and was obtained by merging local and global particle counting sets. We find that Bennu's macroporosity can be significantly smaller than usually assumed (e.g., (Britt 2002, 2011), as the observed size-frequency distribution allows for an efficient packing of boulders, resulting in a macroporosity of 15± 3 %.. Bennu's high bulk porosity must therefore be a direct consequence of very large boulder microporosity. Furthermore, using estimates of the two main types of boulder microporosity of 52% and 31% as derived from remote-sensing thermal inertia measurements (Rozitis+ 2020), the average grain density in boulders is 2794±250 kg m³, similar to values obtained for CM, CI, and the Tagish lake meteorites. Bennu's bulk porosity corresponding to the above values is 57 %. Bennu’s macroporosity is very similar to that of Ryugu (Grott+ 2020), which we present for comparison.

Zero-tillage (ZT) is being increasingly adopted globally as a conservationist management system due to the environmental and agronomic benefits it provides. However, there remains little information on the tillage effect on soil pore characteristics such as shape, size and distribution, which in turn affect soil physical, chemical and biological processes. X-ray micro Computed Tomography (μCT) facilitates a non-destructive method to assess soil structural properties in three-dimensions. We used X-ray μCT at a resolution of 70 μm to assess and calculate the shape, size and connectivity of the pore network in undisturbed soil samples collected from a long-term experiment (~30 years) under zero tillage (ZT) and conventional tillage (CT) systems in Botucatu, Southeastern Brazil. In both systems, a single, large pore (>1000 mm3) typically contributed to a large proportion of macroporosity, 91% in CT and 97% in ZT. Macroporosity was higher in ZT (19.7%) compared to CT (14.3%). However the average number of pores was almost twice in CT than ZT. The largest contribution in both treatments was from very complex shaped pores, followed by triaxial and acircular shaped. Pore connectivity analysis indicated that the soil under ZT was more connected that the soil under CT. Soil under CT had larger values of tortuosity than ZT in line with the connectivity results. The results from this study indicate that long-term adoption of ZT leads to higher macroporosity and connectivity of pores which is likely to have positive implications for nutrient cycling, root growth, soil gas fluxes and water dynamics., Highlights • Soil macro-porosity was higher under zero-tillage than conventional tillage. • Conventional tillage increases the number of pores but decreases the connectivity between them. • Zero-tillage presented lower values of pore tortuosity, indicating better connectivity. • Long term zero tillage improves soil pore connectivity. • 3D analyses of pore shape indicated difference between tillage systems.

Macroporous and hierarchically macro/mesoporous materials (mostly monoliths and microspheres) have attracted much attention for a variety of applications, such as supporting or enabling materials in chromatography, energy storage and conversion, catalysis, biomedical devices, drug delivery systems, and environmental remediation. A well-succeeded method to obtain these tailored porous materials relies on the sol-gel technique, combined with phase separation by spinodal decomposition, and involves as well emulsification as a soft template, in the case of the synthesis of porous microspheres. Significant advancements have been witnessed, in terms of synthesis methodologies optimized either for the use of alkoxides or metal–salts and material design, including the grafting or immobilization of a specific species (or nanoparticles) to enable the most recent trends in technological applications, such as photocatalysis. In this context, the evolution, in terms of material composition and synthesis strategies, is discussed in a concerted fashion in this review, with the goal of inspiring new improvements and breakthroughs in the framework of porous materials.

Intrinsic material skills have a deep effect on the mechanical and biological performance of bone substitutes, as well as on its associated biodegradation properties. In this work we have manipulated the preparation of collagenous derived fiber mesh frameworks to display a specific composition, morphology, open macroporosity, surface roughness and permeability characteristics. Next, the effect of the induced physicochemical attributes on the scaffold's mechanical behavior, bone bonding potential and biodegradability were evaluated. It was found that the scaffold microstructure, their inherent surface roughness, and the compression strength of the gelatin scaffolds can be modulated by the effect of the cross-linking agent and, essentially, by mimicking the nano-scale size of hydroxyapatite in natural bone. A clear effect of bioactive hydroxyapatite nano-rods on the scaffolds skills can be appreciated and it is greater than the effect of the cross-linking agent, offering a huge perspective for the upcoming progress of bone implant technology. Fil: Sartuqui, Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentina Fil: Gravina, Noel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentina Fil: Rial, Ramón. Universidad de Santiago de Compostela. Facultad de Física; España Fil: Benedini, Luciano Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentina Fil: Yahia, L'Hocine. École Polytechnique de Montréal; Canadá Fil: Ruso, Juan M.. Universidad de Santiago de Compostela. Facultad de Física; España Fil: Messina, Paula Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentina

The severe limitation of agricultural land productivity induced by physical soil degradation has become a major concern in semiarid climates, especially in the Eastern Cape Province, South Africa. A randomized complete block design in a split-split-plot arrangement was used to evaluate the short-term (2012&ndash, 2015) effects of tillage (no-till (NT) and conventional tillage (CT)), rotation (maize-fallow-maize (MFM), maize-fallow-soybean (MFS), maize-wheat-maize (MWM) and maize-wheat-soybean (MWS)) and residue management (residue removal (R&minus, ) and residue retention (R+)) on bulk density (BD), penetration resistance (PR), soil hydraulic conductivity (Ks) and macroporosity hydraulic conductivity. The interaction of tillage &times, crop rotation &times, residue management was not significant (p &gt, 0.05) with respect to BD, PR, Ks and macroporosity. The MFM rotation had the highest BD (1.40 g cm&minus, 3), followed by MWM rotation (1.36 g cm&minus, 3), and the least BD was observed in the MFS rotation (1.29 g cm&minus, 3). Penetration resistance was significantly higher in CT (2.43 MPa) compared to NT (1.46 MPa). The study concludes that inclusion of MFS and MWS rotations can potentially reduce BD in the short term. Similarly, conversion from CT to NT reduces soil resistance.

Background The Zarqa River (ZR) is located in the northern part of Jordan and supplies King Talal Dam (KTD). The streamflow that discharges into KTD is composed of treated wastewater from the Khirbat Es-Samra water treatment plant (KTP) and runoff generated during the winter season. Thus, during the summer, the streamflow of the ZR is dominated by effluent from the KTP. Due to the severe scarcity of water in Jordan, a portion of the streamflow is utilized for irrigated agriculture in the ZR valley, located between the KTP and KTD. The groundwater in the vicinity of the ZR is vulnerable to contamination—a risk that may be exacerbated by the potential occurrence of preferential flow (PF). Therefore, the PF in the soils near the ZR should be carefully considered. Methods The macropore flux fraction (Qmacro) and macroscopic capillary length (λc) were determined from in situ measurements using a tension infiltrometer equipped with an infiltration disc with a diameter of 20 cm. The macropore was defined as the pore size that drains at a tension of less than —-3— cm. The λc less than 80 mm was considered to be an indication of PF. The measurements were taken at 69 sites along the ZR between the KTP and KTD. At each measurement site, the soil organic matter content (OM) and soil texture were determined using a composite soil sample obtained by excavating the soil beneath the infiltration disc to a depth of 10 cm. Results The data was split into two groups: the matrix flow group (MF), which includes data associated with λc > 80 mm, and the PF group, which includes data associated with λc < 80 mm. The Qmacro values of 0.67 and 0.57, respectively, for PF and MF were significantly different at p t-test). The flow rates at h=0 were generally well associated with λc, as attested to by a significant difference between the averages of PF (57.8 mm/hr) and MF (21.0 mm/hr) at p t-test). The OM was positively associated with PF. This was statistically confirmed by a t-test at p p Conclusion The OM was positively associated with PF. Soil texture—and clay content in particular—influenced the λcvalues. However, the association of clay content with PF was not statistically significant. Consideration of the SOC/clay ratio showed that the tendency toward PF increases as the complexation of the clay content increases. This was most obvious in soils with a clay content of greater than 8% and SOC/clay of approximately 10%. The OM either influences or is inter-correlated with the processes responsible for the formation of macropores.

Made available in DSpace on 2020-12-10T16:37:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-09-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Large expanses of riparian vegetation have been destroyed in Brazil, and few studies have focused on biological indicators of soil quality in Brazilian riparian ecosystems. The aim of this study was to assess relationships between the soil fauna and physical, chemical, and biological soil attributes in summer and winter, and to identify the indicators that most effectively distinguish between four study sites in Brazilian Seasonal Semideciduous Forest with different ages: one undisturbed site (NT), and three that have been recovering from disturbance for 5 (R05), 10 (R10), and 20 (R20) years. At each site we overlaid a grid with 30 intersections and selected 15 of them at random for soil sampling (n = 15 points per site). Physical, chemical, and biological (microbiological and soil macrofauna) analyses were performed on these samples. The soil fauna was sampled by two methods (pitfall traps and soil monoliths measuring 25 x 25 x 20 cm) and macrofaunal diversity quantified as richness, cumulated richness, and with Shannon's and Pielou's indices. Patterns in macrofaunal distribution were explored with the parallel discrimination rate and partial redundancy analysis (pRDA) to determine how physical, chemical, and biological attributes affect these patterns. We observed lower Shannon's and Pielou's indices in the winter, for both sampling methods, especially at the most recently recovered site. For monoliths, Hymenoptera were more abundant in the winter and for pitfall traps Mollusca and Chilopoda were only found during summer. Richness, Shannon's and Pielou's indices were only higher at the oldest sites (native and 20 years old) with the monolith data collected in winter. The parallel discrimination rate revealed significant separation between sites, sampling methods, and seasons and indicated Hymenoptera, Diplopoda, Coleoptera, and predators such as Araneae and Opiliones as the principal discriminatory groups. Soil chemistry explained the largest proportion of the pRDA inertia, followed by microbiological and physical attributes. Litter and soil nitrogen content, macroporosity, litter humidity, and microbiological activity and biomass were related most strongly with saprophytic groups and with the oldest sites. These results suggest that organic matter quality and physical soil attributes, in addition to management practices, can accelerate the forest recovery process. (C) 2013 Elsevier Masson SAS. All rights reserved. Sao Paulo State Univ USP, Dept Soil Sci, BR-13418900 Piracicaba, SP, Brazil Santa Catarina State Univ UDESC CEO, Dept Anim Sci, BR-89815630 Chapeco, SC, Brazil Sao Paulo State Univ USP, Dept Soil Sci, BR-13418900 Piracicaba, SP, Brazil

Structural porosity is a decisive property for soil productivity and soil environmental functions. Hydraulic properties in the structural range vary over time in response to management and environmental influences. Although this is widely recognized, there are few field studies that determine dominant driving forces underlying hydraulic property dynamics. During a three year field experiment we measured temporal variability of soil hydraulic properties by tension infiltrometry. Soil properties were characterized by hydraulic conductivity, effective macroporosity and Kosugi's lognormal pore size distribution model. Management related influences comprised three soil cover treatment (mustard and rye vs. fallow) and an initial mechanical soil disturbance with a rotary harrow. Environmental driving forces were derived from meteorological and soil moisture data. Soil hydraulic parameters varied over time by around one order of magnitude. The coefficient of variation of soil hydraulic conductivity K(h) decreased from 69.5% at saturation to 42.1% in the more unsaturated range (− 10 cm pressure head). A slight increase in the Kosugi parameter showing pore heterogeneity was observed under the rye cover crop, reflecting an enhanced structural porosity. The other hydraulic parameters were not significantly influenced by the soil cover treatments. Seedbed preparation with a rotary harrow resulted in a fourfold increase in macroporosity and hydraulic conductivity next to saturation, and homogenized the pore radius distribution. Re-consolidation after mechanical loosening lasted over 18 months until the soil returned to its initial state. The post-tillage trend of soil settlement could be approximated by an exponential decay function. Among environmental factors, wetting-drying cycles were identified as dominant driving force explaining short term hydraulic property changes within the season (r2 = 0.43 to 0.59). Our results suggested that beside considering average management induced changes in soil properties (e.g. cover crop introduction), a dynamic approach to hydrological modeling is required to capture over-seasonal (tillage driven) and short term (environmental driven) variability in hydraulic parameters., Highlights • Variability of hydraulic properties decreases from macropore to unsaturated range. • Management effects are over-seasonal, environmental effects within the season. • Mechanical disturbance has a higher impact compared to plant based measures. • Rye increases pore heterogeneity, tillage gives a temporarily higher median radius. • Wetting–drying intensity is a dominant driving force of hydraulic properties.

The present study provides evidence of the effectiveness of some termite species in restoring barren soil and in maintaining long-term soil productivity, thereby facilitating sustainable agriculture in sub-Saharan West Africa. Fungus-growers, in particular, move large quantities of soil to cover their food sources with ‘soil sheetings’, which protect the termites during foraging. We selected study sites in northern Burkina Faso from four age-stages of the traditional restoration system Zai, thus spanning three decades of soil restoration—barren, crusted land, a millet field, and two reforested sites. In a randomized block design, termites were attracted to different organic materials. The aim was to assess the impact of their foraging structures (soil sheetings, foraging holes) on the restoration progress. We quantified soil turnover by termites, macroporosity, water infiltration rate, and physicochemical soil properties. Fungus-growing Odontotermes and Macrotermes species were the decisive soil engineers throughout the year, but only Odontotermes initiated the restoration process. The dry weight of soil bioturbated during the dry season ranged between 216 and 32 tons ha−1 mon−1 in the most rehabilitated Zai forest and the barren area, respectively. By creating tunnels, the foraging activity of termites increased the water infiltration rate by a factor of 2 to 4. Sheetings built on compost and hay showed significant increase in most parameters relevant for plant growth, especially during the dry season. However, the benefits resulting from the termites’ tunnelling activities (improved water availability and soil aeration via macropores, soil turnover) are in the early stages of Zai restoration likely to be more essential than the increased nutrient contents in sheeting soil, since water deficit leads to sapling mortality much faster than nutrient shortage. Our study revealed that the impact of termites is dependent on the particular species and their ecological requirements. Further studies in other areas are urgently required to clarify how generally valid our results are.

Modelling and monitoring of hydrological processes in the unsaturated zone of the chalk, which is a porous medium with fractures, is important to optimize water resources assessment and management practices in the United Kingdom (UK). However, efficient simulations of water movement through chalk unsaturated zone is difficult mainly due to the fractured nature of chalk, which creates high-velocity preferential flow paths in the subsurface. Complex hydrology in the chalk aquifers may also influence land surface mass and energy fluxes because processes in the hydrological cycle are connected via non-linear feedback mechanisms. In this study, it is hypothesized that explicit representation of chalk hydrology in a land surface model influences land surface processes by affecting water movement through the shallow subsurface. In order to substantiate this hypothesis, a macroporosity parameterization is implemented in the Joint UK Land Environment Simulator (JULES), which is applied on a study area encompassing the Kennet catchment in the Southern UK. The simulation results are evaluated using field measurements and satellite remote sensing observations of various fluxes and states in the hydrological cycle (e.g., soil moisture, runoff, latent heat flux) at two distinct spatial scales (i.e., point and catchment). The results reveal the influence of representing chalk hydrology on land surface mass and energy balance components such as surface runoff and latent heat flux via subsurface processes (i.e., soil moisture dynamics) in JULES, which corroborates the proposed hypothesis.

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:25:56Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:41:48Z : No. of bitstreams: 1 2-s2.0-80053018494.pdf: 102604 bytes, checksum: 7d52c10432b2ebe74d52f935edc09781 (MD5) Made available in DSpace on 2014-05-27T11:25:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-07-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) With the use of no-till farming, the soil physical and chemical properties are constantly changed, directly reflecting on plant yield and composition. In 2006, in the municipality of Selvíria, Mato Grosso do Sul, Brazil, the linear and spatial correlations between the plant attributes and the attributes of a Rhodic Hapludox were analyzed. The objective of this work was to select among the analyzed soil attributes the one that best explained the variability of agricultural yield. For this, the geostatistical grid was installed for the soil and plant collection in 124 sampling points in a 4,000 m 2 area. In the soil samples, collected at three depths (0-0.10 m, 0.20-0.30 m and 0.10-0.20 m), the microporosity, macroporosity, total porosity, bulk density and organic matter content were determined. In the plant, the yield (fresh and dry matter) and the crude protein content were determined. From the spatial viewpoint, there was a direct correlation between the dry matter yield and the soil organic matter content, as well as an inverse correlation between the crude protein content and the macroporosity and total porosity of soil. Therefore, the surface organic matter content behaved as a soil chemical quality indicator to estimate the dry matter yield of Cajanus cajan L. under the conditions of this research. Universidade Estadual Paulista (UNESP) Faculdade de Ciências Agrárias e Veterinárias Campus de Jaboticabal, Av. Prof.Paulo Donato Castellane, s/n, CEP 14884-900, Jaboticabal- SP Universidade Estadual Paulista (UNESP) Faculdade de Engenharia de Ilha Solteira Departamento de Fitossanidade Engenharia Rural e Solos, Avenida Brasil, 56, Centro, CEP 15385-000, Ilha Solteira-SP Universidade Estadual de Mato Grosso Do sul (UEMS) Campus de Aquidauana, Rodovia Aquidauana/UEMS - Km 12, Rural, CEP 79200-000, Aquidauana-MS Bolsista de Doutorado da FAPESP Bolsista de Produtividade em Pesquisa Do CNPq Universidade Estadual Paulista (UNESP) Faculdade de Ciências Agrárias e Veterinárias Campus de Jaboticabal, Av. Prof.Paulo Donato Castellane, s/n, CEP 14884-900, Jaboticabal- SP Universidade Estadual Paulista (UNESP) Faculdade de Engenharia de Ilha Solteira Departamento de Fitossanidade Engenharia Rural e Solos, Avenida Brasil, 56, Centro, CEP 15385-000, Ilha Solteira-SP

A variety of cryogenically-structured polymeric materials are of significant scientific and applied interest in various areas. However, in spite of considerable attention to these materials and intensive elaboration of their new examples, as well as the impressive growth in the number of the publications and patents on this topic over the past two decades, a marked variability of the used terminology and definitions is frequently met with in the papers, reviews, theses, patents, conference presentations, advertising materials and so forth. Therefore, the aim of this brief communication is to specify the basic terms and definitions in the particular field of macromolecular science.

To test the assumption that changes to earthworm communities subsequently affect macroporosity and then soil water infiltration, we carried out a 3 year study of the earthworm communities in a experimental site having six experimental treatments: 2 tillage management systems and 3 cropping systems. The tillage management was either conventional (CT; annual mouldboard ploughing up to −30 cm depth) or reduced (RT; rotary harrow up to −7 cm depth). The 3 cropping systems were established to obtain a wide range of soil compaction intensities depending on the crop rotations and the rules of decision making. In the spring of 2005, the impact of these different treatments on earthworm induced macroporosity and water infiltration was studied. During the 3 years of observation, tillage management had a significant effect on bulk density (1.27 in CT and 1.49 mg m−3 in RT) whereas cropping system had a significant effect on bulk density in RT plots only. Tillage management did not significantly affect earthworm abundance but significantly influenced the ecological type of earthworms found in each plot (anecic were more abundant in RT). On the contrary cropping system did have a significant negative effect on earthworm abundance (104 and 129 ind. m−2 in the less and most compacted plots, respectively). Significantly higher numbers of Aporrectodea giardi and lower numbers of Aporrectodea caliginosa were found in the most compacted plots. CT affected all classes of porosity leading to a significant decrease in the number of pores and their continuity. Only larger pores, with a diameter superior to 6 mm, however, were adversely affected by soil compaction. Tillage management did not change water infiltration, probably because the increase in macroporosity in RT plots was offset by a significant increase in soil bulk density. However, cropping system had a significant effect on water infiltration (119 vs 79 mm h−1 in the less and most compacted plots, respectively). In RT plots, a significant correlation was observed between larger macropores (diameter > 6 mm) and water infiltration illustrating the potential positive effect of earthworms in these plots

El objeto del presente proyecto consiste en estudiar la variabilidad del gas contenido en el aluminio en el proceso de fabricación de llantas por moldeo a baja presión en la empresa Mapsa. Para ello se realizará un análisis centrado en las primeras etapas del proceso (en las áreas de Fusión y Moldeo), en el que se investigarán cuáles, y de qué modo, son los parámetros ambientales y de proceso que afectan al nivel de gas, y en consecuencia a la colabilidad del aluminio. Todo ello con la finalidad de implantar medidas correctoras que consigan reducir el número de rechazos de llantas, en controles de calidad, que detectan defectos asociados a niveles inadecuados de gas The purpose of this project is to study the variability of gas of aluminum in the manufacturing process of aluminum wheels in Low-Pressure Die-Cast in Mapsa factory. This requires an analysis of the early stages of the process (in the areas of Melting and Casting) where will be investigated which are the environmental and process parameters that affect the level of gas, and consequently the castability of aluminum. All of this, in order to implement corrective actions succeeds in reducing the number of rejections of tires, in quality control, which detect defects associated with inadequate gas levels Máster Universitario en Ingeniería Industrial por la Universidad Pública de Navarra Nafarroako Unibertsitate Publikoko Unibertsitate Masterra Industria Ingeniaritzan

As áreas irrigadas caracterizam-se pela intensificação dos cultivos e, por conseqüência, por uma intensa utilização do solo. Isso resulta em uma maior pressão de degradação da estrutura do solo, ocasionando muitas vezes a compactação dos solos. O objetivo deste trabalho foi realizar a caracterização física dos solos irrigados de algumas regiões do Estado do Rio Grande do Sul, com vistas a promover uma base de informações para orientar a tomada de decisões relativas ao manejo de áreas irrigadas. Os perfis dos solos foram divididos em três camadas: (superficial, intermediária e inferior), nas quais determinaram-se a textura do solo, a densidade do solo (Ds) e de partículas e porosidade. Os solos foram agrupados em faixas de teor de argila, sendo que, para cada faixa de teor de argila, estabeleceu-se um valor crítico de densidade do solo (Ds) e de macroporosidade (Macro). As amostras com valores DS maiores que o valor cítrico e com valores de macro menores que o valor cítrico foram caracterizados com indicação de compactação. As amostras de solo coletadas foram classificadas, com maior freqüência na faixa de 400-500g kg-1 de argila, nas camadas superficial e intermediária e na faixa de argila superior a 700g kg-1 na camada inferior. Do total das áreas amostradas, 66,5% apresentaram indicação de compactação do solo na camada superficial, 20,5% na camada intermediária e 9,5% na camada inferior. Irrigated areas are characterized by an intensification of the land use, and as consequence, an intense use of the soil. This usually results in a higher pressure of the soil structure degradation, causing many times soil compaction. The objective of this study was to conduct a soil physical characterization of irrigated areas of Rio Grande do Sul State-Brazil and collect informations necessary to guide soil management decisions. The soil profile was divided in to three soil layers: superficial, intermediate and inferior. The following determinations were conducted: soil texture, bulk density (Bd), particles density and soil porosity. Soil types were grouped in ranges of clay content. For each clay content, a critical value of Bd and soil macroporosity (Macro) were established (when the result of soil was the Bd and below the macro) to classify the soil as compacted. The majority of soil samples colleted was classified in the range of 400-500 g Kg-1 of clay content in the superficial and intermediate soil layers and in the range higher than 700 g Kg-1 in the inferior soil layer. Considering the entire area sampled, 66.5% of the samples presented indication of soil compaction in the superficial layer, 20.5% in the intermediate layer and 9.5% in the inferior layer.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:46:53Z No. of bitstreams: 1 S0100-204X2005001100012.pdf: 341636 bytes, checksum: 6403a66649ca30303e616f689e44df92 (MD5) Made available in DSpace on 2013-08-22T18:46:53Z (GMT). No. of bitstreams: 1 S0100-204X2005001100012.pdf: 341636 bytes, checksum: 6403a66649ca30303e616f689e44df92 (MD5) Previous issue date: 2005-11-01 Made available in DSpace on 2013-09-30T19:36:26Z (GMT). No. of bitstreams: 2 S0100-204X2005001100012.pdf: 341636 bytes, checksum: 6403a66649ca30303e616f689e44df92 (MD5) S0100-204X2005001100012.pdf.txt: 19330 bytes, checksum: a2714afc3e3dd6f3f08b69df9341989f (MD5) Previous issue date: 2005-11-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T15:09:48Z No. of bitstreams: 2 S0100-204X2005001100012.pdf: 341636 bytes, checksum: 6403a66649ca30303e616f689e44df92 (MD5) S0100-204X2005001100012.pdf.txt: 19330 bytes, checksum: a2714afc3e3dd6f3f08b69df9341989f (MD5) Made available in DSpace on 2014-05-20T15:09:48Z (GMT). No. of bitstreams: 2 S0100-204X2005001100012.pdf: 341636 bytes, checksum: 6403a66649ca30303e616f689e44df92 (MD5) S0100-204X2005001100012.pdf.txt: 19330 bytes, checksum: a2714afc3e3dd6f3f08b69df9341989f (MD5) Previous issue date: 2005-11-01 O objetivo deste estudo foi avaliar o efeito de diferentes sistemas de manejo, nos atributos físicos de um Neossolo Quartzarênico e de um Latossolo Vermelho. Foram avaliados a densidade do solo, o volume total de poros e a resistência mecânica à penetração. Todos os sistemas de manejo e uso do solo promoveram aumento na densidade, diminuição do volume total de poros e variação da resistência do solo à penetração. No Neossolo Quartzarênico houve diminuição da macroporosidade. The objective of this work was to evaluate the effect of different management systems in soils physical attributes of a Typic Quartzipisamment and of a Rhodic Hapludox. Evaluations were made for the soil density, the total volume of pores and the mechanical resistance to the penetration of the soil. Both management systems and the use of the soil promoted increase in the density of the soil, decrease of the total volume of pores and variation of the resistance of the soil to the penetration. The Typic Quartzipisamment presented decrease of the macroporosity. Universidade Estadual Paulista Dep. de Fitossanidade Universidade Federal de Goiás (UFG) Centro de Ciências Agrárias e Biológicas Laboratório de Solos Universidade Estadual Paulista Dep. de Fitossanidade

Depuis plusieurs années, la Zone Non Saturée d'une parcelle expérimentale au nord de l'Italie (plaine du Pô) a fait l'objet de nombreuses études sur les caractéristiques physiques et géologiques du milieu, ainsi que sur les modalités du mouvement des eaux d'infiltration. Le site a été équipé de 6 tensiomètres à mercure, 6 bougies poreuses pour l'échantillonnage de l'eau et d'un tube d'accès pour la sonde à neutrons.L'application des différentes méthodes d'évaluation a fourni, pour la période d'étude (Septembre 1994-Août 1995), des valeurs de l'infiltration sensiblement différentes. La méthode physique, basée sur le calcul du bilan hydrique annuel, et considérant le sol comme un unique réservoir monocouche, a indiqué que 19% du total des précipitations arrive à s'infiltrer. D'autre part, un modèle de simulation intégrant les caractéristiques hydrodynamiques du sol a permis d'évaluer la recharge à 29% des précipitations annuelles. Le calcul de la répartition de la teneur en eau sur le profil porte sur la description des fluctuations temporelles du plan de flux nul, en relation avec les épisodes pluvieux et l'intensité de l'évaporation.La méthode géochimique du "profil en ions conservés" entre l'eau de pluie et du sol a permis, quant à elle, d'évaluer la lame d'eau infiltrée à environ 12% des précipitations annuelles. La composition isotopique des eaux extraites du sol manifeste un enrichissement global en isotopes lourds (2H et 18O) par rapport aux eaux météoriques, conséquence d'une évaporation intense. L'infiltration semble être de type "piston flow" dispersif. Elle suit, seulement pendant l'hiver, un flux où la composante convective dans la microporosité est prédominante sur la composante diffusive qui a lieu, de préférence, dans la macroporosité., In groundwater management, it is necessary to define water movement, evaluate infiltration and evapotranspiration rates, and quantify the physico-chemical evolution of transported solutes throughout the unsaturated zone (UZ). Traditionally, in temperate regions, recharge rate is evaluated by the comparison between physical methods (based on direct measurements of hydrological parameters with lysimeters, tensiometers and neutron gauges) and geochemical approaches (conservative ions, stable isotope profiles and artificial tracers).In the Po Plain (Northern Italy) intensive agricultural irrigation and overexploitation of groundwater profoundly affect the quality and availability of shallow groundwater resources. The region has been intensively cultivated with corn and rice during the last 5 centuries. Irrigation canals have been constructed in order to distribute water from alpine rivers to areas more favourable to agriculture. In the past, only the water balance method has been applied to obtain recharge rates in these situations.An experimental field site has been operational since 1987 in the ENEA-EUREX Nuclear Centre of Saluggia. The experimental plot represents an unsaturated zone in fluvio-glacial deposits (Holocene) of the Dora Baltea River, formed by gravel and sand, interlayered with silt levels. The water table is usually at a depth of 200 cm but it varies as a function of the river level. The objectives of the present study were to describe water movement throughout the UZ and to evaluate infiltration and evapotranspiration rates using different physico-chemical methodologies. The Saluggia plot was equipped with six tensiometers, a neutron gauge hole and 6 porous cups, up to a depth of 160 cm.During 10 years of monitoring, the most favourable period for understanding infiltration processes and water movement through the UZ is September 1994 - August 1995. This period is characterised by an exceptional rain event (300 mm in 48 hours), followed by a river flood. Water samples collected with porous cups at various depths have been analysed for chemistry and stable isotope composition, together with rainfall and Dora Baltea River water.In October 1994 (beginning of the rainy period) and May 1995 (beginning of the dry period) soil samples were collected at different depths and water was extracted under vacuum conditions. Stable isotope analyses were performed on extracted waters. Soil samples were also analysed for granulometry, chemical and mineralogical composition.Reducing soil to an unique monolayer aquifer, the water balance method suggests that only 19% of the total precipitation infiltrates, whereas a simulation model taking into account soil hydrodynamic characteristics estimates an infiltration rate of 29% of the rainfall. The position of the Zero Flux Plane (ZFP) fluctuates seasonally between the surface and the maximum studied depth, as a consequence of precipitation events and evaporation fluxes. In some periods, the ZFP is level with the water table and direct discharge may occur.Measurements of the stable isotopic composition (δ2H and δ18O) of soil water allows a quantitative estimate of direct groundwater discharge. On a δ2H versusδ18O plot, pore waters from the UZ have an isotopic composition that differs from that of the majority of groundwater samples, plotting below the local rain water line and indicating some degree of evaporation during the recharge process. The isotopic enrichment is particularly significant at the evaporation front, suggesting that pore water in soil reflects a different recharge regime from those of the regional ground waters. Water isotope and solute composition were substantially modified from their original composition during the infiltration process within the soil, via mechanisms such as anion exchange with soil particles, salt precipitation/dissolution or isotopic fractionation.Arial recharge was also evaluated using the depth distribution of a conservative solute. Assuming that chloride is derived from precipitation alone, Cl- content in soil and in rain water suggests that 12% of total rainfall infiltrates. Therefore, the recharge rate is estimated to be less than 100 mm/a. These data are in agreement with other results obtained by the chloride concentration profile method, in areas of the Po Valley, but are considerably different from those evaluated by the traditional physical methods.

RF hydrogels were synthesized by the sol-gel polycondensation of resorcinol with formaldehyde and RF cryogels were prepared by freeze drying of the hydrogels with t-butanol. The cryogels were characterized by nitrogen adsorption, density measurements, and scanning electron microscope. Their porous properties were compared with those of the aerogels prepared by supercritical drying with carbon dioxide. RF cryogels were mesoporous materials with large mesopore volumes >5.8× 10−4m3/kg. Although surface areas and mesopore volumes of the cryogels were smaller than those of the aerogels, the cryogels were useful precursors of mesoporous carbons. Aerogel-like carbons (carbon cryogels) were obtained by pyrolyzing RF cryogels in an inert atmosphere. The carbon cryogels were mesoporous materials with high surface areas >8.0× 105m2/kg and large mesopore volumes >5.5× 10−4m3/kg. When pyrolyzed, micropores were formed inside the cryogels more easily than inside the aerogels.

Water vapor permeability is a critical parameter in textile fabric comfort evaluation as it represents the ability of the fabric to transfer perspiration coming out of the human body. Clothing materials with high water vapor permeability allow the human body to take advantage of its ability to provide cooling due to the sweat production and evaporation. The influence of several factors such as the fabric structure, thickness, porosity and fiber type on water vapor permeability of common clothing materials was observed by previous researchers. The main objective of this study was to analyze the influence of yarn properties on water vapor permeability of plain knitted fabrics. The range of various yarn structures was obtained by applying different twist intensity during spinning. From three various twisted cotton yarns the knitted fabrics were produced under controlled conditions. Water vapor permeability and air permeability of the knitted fabrics were measured. The results obtained indicated the complex impact of the yarn core and surface geometry on water vapor permeability of plain knitted fabrics. The hairiness of yarn was proved as the parameter with great potential in terms of the water vapor transfer. Propustljivost vodene pare je jedan od ključnih parametara u proceni komfora tekstilnog materijala, budući da definiše materijal u pogledu sposobnosti da propušta produkte znojenja ljudskog tela. Odevni tekstilni materijal sa većom propustljivošću vodene pare ne ometa efekte hlađenja ljudskog organizma putem znojenja i isparavanja znoja. Predmet interesovanja dosadašnjih istraživanja odnosio se na uticaj strukture, debljine, poroznosti materijala kao i vrste vlakana na propustljivost vodene pare. Osnovni cilj ovog rada bio je analiza uticaja svojstava pređe na propustljivost vodene pare glatkih pletenina. Različita struktura pređa je ostvarena primenom različitog intenziteta upredanja. Polazeći od tri različito upredene pamučne pređe u kontrolisanim uslovima su proizvedene glatke pletenine koje su podvrgnute ispitivanju propustljivosti vodene pare i vazduha. Dobijeni rezultati su ukazali na kompleksan uticaj koji geometrija jezgra i površine pređe imaju na propustljivost vodene pare glatkih pletenina. Pokazalo se da maljavost pređe predstavlja parametar koji ima veliki potencijal u pogledu prenosa vodene pare kroz tekstilne materijale.

Boyuan Yang,1 Yi Zuo,1 Qin Zou,1 Limei Li,1 Jidong Li,1 Yi Man,2 Yubao Li1 1Research Center for Nano Biomaterials, Analytical and Testing Center, Sichuan University, Chengdu, People’s Republic of China; 2State Key Laboratory of Oral Disease, West China Hospital of Stomatology, Sichuan University, Chengdu, People’s Republic of China Abstract: We incorporated ultrafine polymer fibers into calcium phosphate cement (CPC) to improve the resorption rate of CPC with fiber degradation. Different weight percentages of electrospun poly(ε-caprolactone) fibers (0%, 3%, and 7%, named as ultrafine fiber-incorporated CPC0 [UFICPC0], UFICPC3, and UFICPC7) were included into preset CPC specimens for in vitro immersion in lipase phosphate-buffered solution and long-term in vivo implantation in the femoral condyle of rabbits. The effect of the ultrafine poly(ε-caprolactone) fibers with a diameter ranging from nanometer to micrometer on CPC degradation was evaluated by measuring the pH of the medium, mass loss, porosity, and physiochemical properties. For the in vivo evaluation, histomorphometrical analysis as well as three-dimensional (3D) reconstruction was applied to assess the osteogenic properties of the CPC composite. After in vitro immersion and in vivo implantation, the total porosity and macroporosity as well as the bone formation and ingrowth increased significantly during time in the fiber-incorporated CPC specimens. After 24 weeks of implantation, the degraded space was occupied by newly formed bone, and the UFICPC3 and UFICPC7 composites showed a ~3.5 times higher fraction of bone volume than that of the pristine CPC (UFICPC0). In vitro and in vivo results proved that the introduction of ultrafine degradable fibers within a CPC matrix can be used to improve macroporosity efficiently and enhance CPC degradation and bone ingrowth largely. Keywords: ultrafine fibers, calcium phosphate cement, macroporosity, degraded space, bone ingrowth

Agarose gels have been applied as templates for the formation of macroporous metal oxide structures. The preparation of the agarose template is extremely simple, and with variation of the agarose content, control over morphology is demonstrated: The average pore size decreases from 180 to 55 nm and the surface area increases from 238 to 271 m2 g(-1) with increasing agarose content in the gel. The gelling temperature was also found to influence the final template morphology. Conducting sol-gel chemistry within the template structure followed by removal of the template by heating to 450 degrees C gives porous inorganic oxides. The technique has been demonstrated for the oxides of titanium, zirconium, niobium, and tin. The final morphology of the metal oxide is homogeneous and results from a coating of the agarose structure. The pore diameter decreased and the specific surface area of the titanium dioxide materials increased from 28 to 66 m2 g(-1) as the agarose content in the template is increased from 0.5 to 5.0 wt%. The overall pore size and surface area are lower than the original gel due to shrinkage occurring with the sol-gel process, as well as crystallization and a loss of microporosity in the final material.

Infiltration into soils is strongly correlated with macroporosity. Under agricultural land use, the properties of the macropore network are governed by the applied management and tillage system. On an experimental site with a silt loam soil partly under conventional and conservation tillage, the methods of visual inventarization of stained and unstained macropores and infiltration measurements with an infiltrometer were applied to the macropore system. Dye tracer experiments with methylene blue as tracer agent yielded a penetration depth of 120 cm on the conservation tillage plot while a penetration depth of only 50 cm was recorded on the conventionally tilled plot. For both tillage treatments, infiltration rates were lower in the topsoil than in soil depths >30 cm. The conservation tillage plot showed higher infiltration rates at 50 and 90 cm soil depth than the conventional tilled plot. For both tillage systems, the visual recording of stained and unstained macropores (1 mm) resulted in macropore densities ranging between 100 and 1,000 macropores/m, with the highest numbers in the topsoil and a gradual decrease with soil depth. At the conservation tillage plot, below 20 cm soil depth, macropore density was greater than at the conventionally tilled plot. Macroporosity obtained from the visual registering varied between 0.09% and 0.83% for the conventional tillage plot and between 0.08% and 0.6% for the conservation tillage plot. Macroporosity derived from tension infiltrometry, assuming a minimum macropore radius of 0.5 mm, range between 0.02% and 0.1%, about one order of magnitude lower than the figure obtained from visual inventarization. The results indicate a greater continuity and connectivity of the macropore system for silty soils with conservation tillage systems. Therefore, conservation tillage could possibly offer a means to reduce surface runoff and flood generation in agricultural landscapes dominated by silty-loamy soils. d 2 Infiltration into soils is strongly correlated with macroporosity. Under agricultural land use, the properties of the macropore network are governed by the applied management and tillage system. On an experimental site with a silt loam soil partly under conventional and conservation tillage, the methods of visual inventarization of stained and unstained macropores and infiltration measurements with an infiltrometer were applied to the macropore system. Dye tracer experiments with methylene blue as tracer agent yielded a penetration depth of 120 cm on the conservation tillage plot while a penetration depth of only 50 cm was recorded on the conventionally tilled plot. For both tillage treatments, infiltration rates were lower in the topsoil than in soil depths >30 cm. The conservation tillage plot showed higher infiltration rates at 50 and 90 cm soil depth than the conventional tilled plot. For both tillage systems, the visual recording of stained and unstained macropores (1 mm) resulted in macropore densities ranging between 100 and 1,000 macropores/m, with the highest numbers in the topsoil and a gradual decrease with soil depth. At the conservation tillage plot, below 20 cm soil depth, macropore density was greater than at the conventionally tilled plot. Macroporosity obtained from the visual registering varied between 0.09% and 0.83% for the conventional tillage plot and between 0.08% and 0.6% for the conservation tillage plot. Macroporosity derived from tension infiltrometry, assuming a minimum macropore radius of 0.5 mm, range between 0.02% and 0.1%, about one order of magnitude lower than the figure obtained from visual inventarization. The results indicate a greater continuity and connectivity of the macropore system for silty soils with conservation tillage systems. Therefore, conservation tillage could possibly offer a means to reduce surface runoff and flood generation in agricultural landscapes dominated by silty-loamy soils. d 2

[Abstract] The objective of this research was to study the porosity, bulk density and retention of water of an Oxisol, located in the Northwestern region of São Paulo state, Brazil. The soil was cultivated with Citrus sp., to which green manure was applied between rows for three years. Each of six species of green manure crops (Crotalaria junceaL., Mucunade eringian a Steph. & Bart., Canavalia ensiformis L. DC., Cajanus cajan L., Lablab purpureum L. and Ricinus communis L.) were seeded for three years (1995, 1996 and 1997) between Citrus rows, plus a treatment with a mix of all six species and a control (natural regrowth af vegetation). The experimental design was a randomized complete block design, with four replications for each of the eight treatments. Water retention, microporosity, macroporosity, total porosity and bulk density were analyzed in the beginning (1995) and end (1997) of the experiment, at three depth ranges (0-0.10; 0.10-0.20 and 0.20-0.40m). We concluded that there were statistically significant differences for bulk density, macroporosity, total porosity and retention of water among the different soil depth ranges; there were no significant differences among treatments though.

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Soil structure influences the soil hydraulic properties, aeration and resistance to root penetration. Many indicators can be used to investigate the changes of soil structure, but using a single indicator or method has limitations. This study evaluates the effects of 15-years tillage management on soil structure with soil bulk density (BD), penetrometer resistance (PR), soil water retention curve (SWRC), least limiting water range (LLWR) and X-ray computed tomography (CT). The treatments include no-tillage (NT), rotary tillage (RT), and mouldboard plough (MP). Soil bulk density of the 0–30 cm soil profile was measured after the establishment of tillage treatments for 7, 9, 12 and 14-years. The values of PR, SWRC, LLWR, and 3-D pore geometry of the 5–10 and 15–20 cm layers were determined in the 15th year of the experiment. The greater BD in the 0–5 cm layer of NT was not observed after 9 years, but an increased BD in the 5–20 cm layer was found in most years. Tillage had no effect on PR in wet soil. When soil had dried, the NT treatment had a greater PR and it was the lower limiting factor of LLWR, ultimately leading to a narrower LLWR of NT. Both NT and RT showed lower proportions of structural but higher textural pores. The macroporosity (> 50 µm) from X-ray CT was greater than that estimated from SWRC of the 15–20 cm layer. The characteristics of pore morphology were similar under three tillage treatments. Therefore, NT resulted in a narrower LLWR due to the denser soil layer, yet similar macropores may alleviate the negative impacts on crop growth caused by lower LLWR. It was suggested that using LLWR and characteristics of macropores from X-ray CT at the same time is a suitable way to assess soil structure under various tillage practices.