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This study explores the blending of poly(lactic acid) (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) with rice straw micro-particles (10 to 30 wt%, ≤ 250 μm) to create biocomposites using a kinetic mixer. It examines the effects of chain extender (J) and maleic anhydride (MA) as compatibilizers on material properties. Biocomposites underwent 500 h accelerated weathering to simulate environmental conditions, with analysis via Fourier-transform infrared spectroscopy (FTIR), mechanical testing, dynamic mechanical analyses (DMA), and rheological evaluations. Results indicate that the chain extender's superior performance over MA, generating 6% insoluble content compared to 1% with MA. Scanning electron microscopy (SEM) revealed reduced interfacial voids in biocomposites treated with compatibilizers. The addition of the rice straw was found to increase the tensile modulus from 2.3 to 3.4 indicating a 43% increase after 40 wt% rice particles; all the while reducing the tensile strength and ductility. Post-weathering, Joncryl® treated samples retained properties better than MA-treated ones, showing enhanced crosslinking and less decline in tensile strength (10–19% reduction for J vs. 27–30% for MA). Compatibilizers, especially the chain extender, play a crucial role in strengthening PLA and PBAT biocomposites, particularly under accelerated weathering. [ABSTRACT FROM AUTHOR]

Digital Twins of the Ocean (DTO) are a rapidly emerging topic that has attracted significant interest from scientists in recent years. The initiative, strongly driven by the EU, aims to create a digital replica of the ocean to better understand and manage marine environments. The Iliad project, funded under the EU Green Deal call, is developing a framework to support multiple interoperable DTO using a federated systems-of-systems approach across various fields of applications and ocean areas, called pilots. This paper presents the results of a Water Quality DTO pilot located in the Trondheim fjord in Norway. This paper details the building blocks of DTO, specific to this environmental monitoring pilot. A crucial aspect of any DTO is data, which can be sourced internally, externally, or through a hybrid approach utilizing both. To realistically twin ocean processes, the Water Quality pilot acquires data from both surface and benthic observatories, as well as from mobile sensor platforms for on-demand data collection. Data ingested into an InfluxDB are made available to users via an API or an interface for interacting with the DTO and setting up alerts or events to support 'what-if' scenarios. Grafana, an interactive visualization application, is used to visualize and interact with not only time-series data but also more complex data such as video streams, maps, and embedded applications. An additional visualization approach leverages game technology based on Unity and Cesium, utilizing their advanced rendering capabilities and physical computations to integrate and dynamically render real-time data from the pilot and diverse sources. This paper includes two case studies that illustrate the use of particle sensors to detect microplastics and monitor algae blooms in the fjord. Numerical models for particle fate and transport, OpenDrift and DREAM, are used to forecast the evolution of these events, simulating the distribution of observed plankton and microplastics during the forecasting period. [ABSTRACT FROM AUTHOR]

We report the fabrication and characterisation of near-IR reflecting films and coatings based on shear-assembled crystalline ensembles of polymer composite microspheres, also known as “polymer opals”. Extension of the emulsion polymerisation techniques for synthesis of tractable larger core-interlayer-shell (CIS) particles, of up to half a micron diameter, facilitates the engineering and processing of thin-film synthetic opals, with a tunable photonic stopband spanning an extended spectral range of λ ≈ 700–1600 nm. Samples exhibit strong “scattering cone” interactions, with considerable angular dependence and angle tuning possible, as measured with a goniometric technique. These intense optical resonances in the near-IR, particularly within the important region around λ ~ 800 nm, combined with an appreciable translucency within the visible light spectrum, is indicative of the potential applications in coatings technologies and solar cells.

We report the fabrication and characterisation of near-IR reflecting films and coatings based on shear-assembled crystalline ensembles of polymer composite microspheres, also known as "polymer opals". Extension of the emulsion polymerisation techniques for synthesis of tractable larger core-interlayer-shell (CIS) particles, of up to half a micron diameter, facilitates the engineering and processing of thin-film synthetic opals, with a tunable photonic stopband spanning an extended spectral range of λ ≈ 700–1600 nm. Samples exhibit strong "scattering cone" interactions, with considerable angular dependence and angle tuning possible, as measured with a goniometric technique. These intense optical resonances in the near-IR, particularly within the important region around λ ~ 800 nm, combined with an appreciable translucency within the visible light spectrum, is indicative of the potential applications in coatings technologies and solar cells. [ABSTRACT FROM AUTHOR]

Digital Twins of the Ocean (DTO) are a rapidly emerging topic that has attracted significant interest from scientists in recent years. The initiative, strongly driven by the EU, aims to create a digital replica of the ocean to better understand and manage marine environments. The Iliad project, funded under the EU Green Deal call, is developing a framework to support multiple interoperable DTO using a federated systems-of-systems approach across various fields of applications and ocean areas, called pilots. This paper presents the results of a Water Quality DTO pilot located in the Trondheim fjord in Norway. This paper details the building blocks of DTO, specific to this environmental monitoring pilot. A crucial aspect of any DTO is data, which can be sourced internally, externally, or through a hybrid approach utilizing both. To realistically twin ocean processes, the Water Quality pilot acquires data from both surface and benthic observatories, as well as from mobile sensor platforms for on-demand data collection. Data ingested into an InfluxDB are made available to users via an API or an interface for interacting with the DTO and setting up alerts or events to support ’what-if’ scenarios. Grafana, an interactive visualization application, is used to visualize and interact with not only time-series data but also more complex data such as video streams, maps, and embedded applications. An additional visualization approach leverages game technology based on Unity and Cesium, utilizing their advanced rendering capabilities and physical computations to integrate and dynamically render real-time data from the pilot and diverse sources. This paper includes two case studies that illustrate the use of particle sensors to detect microplastics and monitor algae blooms in the fjord. Numerical models for particle fate and transport, OpenDrift and DREAM, are used to forecast the evolution of these events, simulating the distribution of observed plankton and microplastics during the forecasting period.

Methane hydration is a safe, stable and environmentally friendly technology to bind and utilize excess coalbed methane gas. However, a limiting factor of the commercial application of coalbed methane hydration technology is the sluggish hydration reaction kinetics of methane hydrate formation, which needs to be improved. In this work, different micro-particle suspensions are prepared from an initial solution containing gellan gum and L-tryptophan, along with varying mass fractions of NiMnGa, Cu and carboxylated multi-walled carbon nanotubes, and their influence on the reaction kinetics in methane hydrate formation is examined. The results show that the formation of methane hydrate is enhanced by these micro-particles to varying degrees. Micro-particles show a synergistic solubilization effect with L-tryptophan and gellan gum at 6.2 MPa. The induction times of 1 wt.% NiMnGa system and 1 wt.% Cu system are the shortest. The 2 wt.% NiMnGa system has a pronounced impact on methane gas consumption, and the average gas consumption rates of the 0.1 wt.% Cu system and 1 wt.% NiMnGa system are faster. However, as the concentration of Cu micro-particles increases, both gas consumption and the average generation rate exhibits a linear decrease. This work offers valuable recommendations for choosing the experimental settings, micro-particle types and concentrations. We also lay the groundwork for the practical and sustainable application of coalbed methane storage and transportation technology employing the hydrate approach. [ABSTRACT FROM AUTHOR]

Microplastics, or plastic particles smaller than 5 mm in size, have become ubiquitous in the environment, found in places ranging from remote deep ocean trenches to minute dust particulates. From the breakdown of larger plastic products and the release of synthetic clothing fibers, these particles enter the ecosystem and cycle through the various components including aquatic, terrestrial, and human systems. Due to their durability, capacity to adhere to other toxic compounds, and potential effects on humans and ecosystems, microplastics have recently risen to the forefront of environmental and health concerns. To address these critical issues, there has been a surge in research related to the microplastics cycle, examining where they originate, how and where they travel, and their environmental and human health impacts. Research on the microplastic cycle is often broken down into its various individual components such as sources, fate, and effect, and further scattered through the literature are focuses on specific environments such as land, oceans, and freshwater, as well as on human health. Here, we review the current state of the literature on the microplastic cycle across its various environmental reservoirs. In-depth examination of the microplastics cycle is necessary for understanding the scope of the problem and developing viable solutions or mitigation strategies, such as reducing plastic production and promoting recycling. Understanding the complex microplastics cycle is an urgent issue that necessitates multidisciplinary research and action. [ABSTRACT FROM AUTHOR]

Improper disposal of household and industrial waste into water bodies has transformed them into de facto dumping grounds. Plastic debris, weathered on beaches degrades into micro-particles and releases chemical additives that enter the water. Microplastic contamination is documented globally in both marine and freshwater environments, posing a significant threat to aquatic ecosystems. The small size of these particles makes them susceptible to ingestion by low trophic fauna, a trend expected to escalate. Ingestion leads to adverse effects like intestinal blockages, alterations in lipid metabolism, histopathological changes in the intestine, contributing to the extinction of vulnerable species and disrupting ecosystem balance. Notably, microplastics (MPs) can act as carriers for pathogens, potentially causing impaired reproductive activity, decreased immunity, and cancer in various organisms. Studies have identified seven principal sources of MPs, including synthetic textiles (35%) and tire abrasion (28%), highlighting the significant human contribution to this pollution. This review covers various aspects of microplastic pollution, including sources, extraction methods, and its profound impact on ecosystems. Additionally, it explores preventive measures, aiming to guide researchers in selecting techniques and inspiring further investigation into the far-reaching impacts of microplastic pollution, fostering effective solutions for this environmental challenge. • Improper waste disposal pollutes water bodies, creating dumping grounds. • Microplastics (MPs) threaten aquatic life through ingestion and adverse effects. • The study of MP pollution underscores the imperative to curb its harm to ecosystems. [ABSTRACT FROM AUTHOR]

Microplastics, or plastic particles smaller than 5 mm in size, have become ubiquitous in the environment, found in places ranging from remote deep ocean trenches to minute dust particulates. From the breakdown of larger plastic products and the release of synthetic clothing fibers, these particles enter the ecosystem and cycle through the various components including aquatic, terrestrial, and human systems. Due to their durability, capacity to adhere to other toxic compounds, and potential effects on humans and ecosystems, microplastics have recently risen to the forefront of environmental and health concerns. To address these critical issues, there has been a surge in research related to the microplastics cycle, examining where they originate, how and where they travel, and their environmental and human health impacts. Research on the microplastic cycle is often broken down into its various individual components such as sources, fate, and effect, and further scattered through the literature are focuses on specific environments such as land, oceans, and freshwater, as well as on human health. Here, we review the current state of the literature on the microplastic cycle across its various environmental reservoirs. In-depth examination of the microplastics cycle is necessary for understanding the scope of the problem and developing viable solutions or mitigation strategies, such as reducing plastic production and promoting recycling. Understanding the complex microplastics cycle is an urgent issue that necessitates multidisciplinary research and action.

Soil amendments containing carbonized materials increase the soil carbon reservoir, influence plant productivity, and, ultimately, help to clean the environment. There is data on the effect of such additions on soil physicochemical properties or plant growth, but few studies have focused on how these carbonized materials are distributed by termite species in the soil ecosystem. It is the first comprehensive study of the transportation of biochar (BC) by termite species under tropical environmental conditions in Pakistan. The present study was carried out to test the hypothesis that if termite species I) were involved in the distribution of biochar particles II) if yes, then how far these particles were transported during the study period (10 days) and III) check their preference between the enriched BC (EBC) and non-enriched BC. BC was enriched with the cattle slurry after its pyrolysis in the study. The results showed that EBC particles were significantly more widely distributed than non-enriched BC particles, but both types of BC were transported more than 4 cm (ring 4) within 10 days (at the end of the experiment). The current study also revealed that EBC was easily attached to the setae, cuticle, and legs of termites, implying that it could potentially be transported over a greater distance. Furthermore, transportation of EBC over larger distances indicated a potential preference of termite species between the EBC and BC particles. During the study, however, the preference among the termite species was also observed. Under the prevailing study conditions, the Coptotermes heimi and Heteroterme indicola species transported the EBC further than Microtermes obesi and Odontotermes obesus. These findings revealed that transportation preferences were observed among the four termite species. In conclusion, the current study found that termites were involved in the distribution of BC particles, with a preference for EBC and that these have the potential to transport BC particles more than 4 cm within 10 days. Furthermore, two species Coptotermes heimi and Heteroterme indicola may be more suitable candidates for EBC transpiration in Pakistani soils. It was necessary to conduct additional research into the effect of temperature on the transportation process. [ABSTRACT FROM AUTHOR]

Novel metal-free catalysts were synthesized form maleic acid (MA) and citric acid (CA) based polymers for hydrogen generation form NaBH4. Surfactant-free-self-emulsion polymerization technique was used to synthesize poly(Maleic acid)(poly(MA)), poly(Citric acid)(poly(CA)) and poly(Maleic acid-co-Citric Acid) poly(MA-co-CA)) polymeric micro-particles in a single step. The prepared catalysts were characterized by zeta potential, SEM, FTIR and TGA. The hydrodynamic diameter of the poly(MA), poly(CA) and poly(MA-co-CA) micro-particles were found to be 0.681, 1.273, 1.604 µm and the zeta potential of this micro-particles were found to be −6.90, −5.69 and −7.73 mV, respectively. Various parameters affecting the rate of H2 production of polymeric catalysts, such as the amount of microparticles, the amount of NaBH4 and the ambient temperature were investigated. Hydrogen generation rate(HGR) was calculated as 84 ± 44 ml H2 g−1 min−1 for 50 mg poly(MA-co-CA)micro-particles in the hydrolysis of 50 mM NaBH4. The activation energy(Ea) of hydrolysis of NaBH4 catalyzed by poly(MA-co-CA)micro-particles was calculated as −1.66 ± 0.76 kJ mol−1, which is much lower than similar studies reported in the literature. The prepared poly(CA), poly(MA) and poly(MA-co-CA) micro-particles were shown to be very effective catalysts in H2 generation by hydrolysis of NaBH4. [ABSTRACT FROM AUTHOR]

Separation, classification, and focusing of microparticles are essential issues in microfluidic devices that can be implemented in two categories: using labeling and label-free methods. Label-free methods differentiate microparticles based on their inherent properties, including size, density, shape, electrical conductivity/permittivity, and magnetic susceptibility. Dielectrophoresis is an advantageous label-free technique for this objective. Besides, centrifugal microfluidic devices exploit centrifugal forces to move liquid and particles. The simultaneous combination of dielectrophoretic and centrifugal forces exerted on microparticles still needs to be scrutinized more to predict their trajectories in such devices. An integrated system utilizing two categories in microfluidics is proposed: dielectrophoretic manipulation of microparticles and centrifugal-driven microfluidics, followed by a numerical analysis. In this regard, we assumed a rectangular microchannel with internal unilateral planar electrodes equipped with three equal-sized outlets placed radially on a centrifugal platform where microparticles flow toward the disc's outer edge. The effect of different coordinate-based parameters, including radial and lateral distances (X and Y offsets)/tilting angles toward the radius direction (α), on the particles' movement was investigated. Additionally, the effect of operational parameters, including applied voltage, the microchannel width, the number of enabled electrodes, the diameter of particles, and the configuration of electrodes, were analyzed, and the distributions of particles toward the outlets were monitored. It was found that enhanced particle focusing becomes possible at lower rotation speeds and higher electric field values. Furthermore, the proposed centrifugal-DEP system's efficiency for classifying red blood cells/platelets and Live/Dead yeast cells systems was evaluated. Our integrated system is introduced as a novel method for focusing and classifying various microparticles with no need for sheath flows, having the ability to conduct particles at desired routes and focusing width. Furthermore, the system effectively separates various bioparticles and offers ease of operation and high-efficiency throughput over conventional dielectrophoretic devices. [Display omitted] • A centrifugal-DEP device for various applications including biomedical engineering and diagnostics is proposed. • The proposed system can be prepared using regular methods, making it attractive for further experimental studies. • The proposed centrifugal-DEP device provides advantages over the conventional SpinDEP device. • Live and Dead yeast cells have been separated using a 1 MHz, 5 V electric field at a 70 rad/s rotating speed. • A mixture of RBCs and Platelets was successfully classified at 100 rad/s rotation speed and 15 V electrical potential. [ABSTRACT FROM AUTHOR]

This study is concerned with the theory of Cosserat thermoelastic media, whose micro-particles possess microtemperatures. The mixed initial boundary value problem considered in this context is transformed in a temporally evolutionary equation on a Hilbert space. Using some results from the theory of semigroups, the existence and uniqueness of solution is proved. In the same manner, it approached the continuous dependence of the solution upon initial data and loads. From what we have studied, neither on the internet nor in the databases, we have not found qualitative issues addressed regarding the mixed problem in the context of the theory of thermoelasticity of Cosserat environments, in which the contribution of inner structure and microtemperatures are taken into account. [ABSTRACT FROM AUTHOR]

Hypothesis: Nowadays, the growing concern over environmental pollution has attracted attentions towards development of biodegradable micro-particles to replace non-degradable micro-particles used in cosmetic products. In this regard, poly(lactic-co-glycolic acid) (PLGA) micro-particles produced by a simple technique, electrospraying, is used as biodegradable micro-particles. To obtain the maximum efficiency, especially as a drug delivery system, these particles need to be fiber-free with spherical shape and have a uniform size distribution. This goal can be achieved by controlling variables such as polymer molecular weight, solvent type, polymer solution concentration, voltage, needle size, polymer solution feed rate and distance from needle tip to collector. Methods: PLGA particles were electrosprayed considering four variables, including polymer solution concentration (at three levels), needle size (at two levels), voltage (at three levels), and polymer solution feed rate (at three levels). Then, electron scanning microscopic images were obtained from each sample to observe the morphology of particles and to study the effect of process variables on it. To understand the morphological behavior of the particles, the influence of each variable was investigated according to mechanisms involved in electrospraying process. Findings: The four variables affecting droplet size, and consequently, Peclet number and droplet charge play important roles in mechanisms involved in electrospraying process and determining the morphology of the resultant particles. Thanks to the effects of these phenomena, spherical and fiber-free micro-particles with uniform size were obtained by electrospraying PLGA solutions at concentrations of 3% and 5%, using a 27 G needle at a feed rate of 0.3 mL/h and applying a voltage of 10 kV.

Insoluble and soluble impurities, enclosed in polar ice sheets, have a major impact on the deformation behaviour of the ice. Macro- and Micro-scale deformation observed in ice sheets and ice cores has been retraced to chemical loads in the ice, even though the absolute concentration is negligible. And therefore the exact location of the impurities matters: Allocating impurities to specific locations inside the ice microstructure inherently determines the physical explanation of the observed interaction between chemical load and the deformational behaviour. Both, soluble and non-soluble impurities were located in grain boundaries, triple junctions or in the grain interior, using different methods, samples and theoretical approaches. While each of the observations is adding to the growing understanding of the effect of impurities in polar ice, the growing number of ambiguous results calls for a dedicated and holistic approach in assessing the findings. Thus, we here aim to give a state of the art overview of the development in microstructural impurity research over the last 20 years. We evaluate the used methods, discuss proposed deformation mechanisms and identify two main reasons for the observed ambiguity: 1) limitations and biases of measurement techniques and 2) the physical state of the analysed impurity. To overcome these obstacles we suggest possible approaches, such as the continuous analysis of impurities in deep ice cores with complementary methods, the implementation of these analyses into established in-situ ice core processing routines, a more holistic analysis of the microstructural location of impurities, and an enhanced knowledge-transfer via an open access data base.

Local laser heating of the liquid film leads to simultaneous self-organization of both cellular convective structures and a cluster of micron-scale particles. The cluster is formed on the free surface of the layer and consists of hexagonal structures with a size of 50-100 μm. The height of the liquid film (0.5 mm) is ten times the diameter of the convective cells. Experimental data on the distribution of particle sizes and sizes of hexagonal cells in the cluster are presented. The cluster shape may be either a circle with a diameter of 110-140 μm, or an ellipse. Due to the instability of the velocity field, the toroid is not formed, and convective cells are formed only near the heating center. Self-organization of a cluster of particles and cellular structures using local heating can be effectively used to create new promising materials, as well as in micro-biology and medicine. Unlabelled Image • Convective cells and a cluster of particles are studied at laser heating. • Perturbations at a micro-scale control the average flow at a macro-scale. • The integral convection scale reflects the intensity of heat and mass transfer. [ABSTRACT FROM AUTHOR]

The behavior of self-organization of convective flows in a thin layer of liquid under point (local) heating is investigated experimentally. The interaction of thermocapillary and thermogravitational-free convection can lead both to self-organization of a cluster of micro-vortices in the form of hexagonal structures and to its partial disintegration. Correlation analysis of the velocity field shows that the characteristic convection scales change continuously over time. The largest size of the vortex flow corresponds to the layer diameter (20 mm); the integral convection scale (2.5 mm) characterizes the established interaction of vortex structures in a wide range of sizes; and the dimensions of hexagonal convective cells (80–100 µm) show the lower limit of the characteristic scale of vortex structures. The observed flow macrostructure is determined by the complex nonlinear interaction of vortices of the specified scales. The resulting value of the average integral convection scale can be effectively used to predict the convection velocity. [ABSTRACT FROM AUTHOR]

Silkworm microparticle disease is a legal quarantine standard in the detection of silkworm disease all over the world. The current common detection method, the Pasteur manual microscopy method, has a low detection efficiency all over the world. The low efficiency of the current Pasteur manual microscopy detection method makes the application of machine vision technology to detect microparticle spores an important technology to advance silkworm disease research. For the problems of the low contrast, different illumination conditions and complex image background of microscopic images of the ellipsoidal symmetrical shape of silkworm microparticle spores collected in the detection solution, a region growth segmentation method based on microparticle color and grayscale information is proposed. In this method, the fuzzy contrast enhancement algorithm is used to enhance the color information of micro-particles and improve the discrimination between the micro-particles and background. In the HSV color space with stable color, the color information of micro-particles is extracted as seed points to eliminate the influence of light and reduce the interference of impurities to locate the distribution area of micro-particles accurately. Combined with the neighborhood gamma transformation, the highlight feature of the micro-particle target in the grayscale image is enhanced for region growing. Mea6nwhile, the accurate and complete micro-particle target is segmented from the complex background, which reduces the background impurity segmentation caused by a single feature in the complex background. In order to evaluate the segmentation performance, we calculate the IOU of the microparticle sample image segmented by this method with its corresponding true value image, and the experiments show that the combination of color and grayscale features using the region growth technique can accurately and completely segment the microparticle target in complex backgrounds with a segmentation accuracy IOU as high as 83.1%.

Herein, the preparation of polyurethane nanofibrous microfiltration membranes, with electrospinning and then dip-coating methods was reported. The study of process parameters (i.e. needle-free electrospinning and dip-coating condition) on the membrane properties was also conducted. The different pore sizes of the prepared MF membranes (e.g. 0.23, 0.33, and 0.47 μm) is orchestrated through the adjustment of various electrospinning and dip-coating parameters. The capability of these membranes to simultaneously eliminate the sources of water pollution, i.e. micro-particles and bacteria, has been demonstrated. Specifically, the prepared membranes could thoroughly reject the E. coli BL21 (DE3) bacteria (~ 97–99%) as well as micro-particles through size extrusion mechanism (~ 95–99%), while they retained a high permeation flux (~ 65,400, ~ 40,000 and ~ 25,700 (L/m2 h bar) for 0.46, 0.33, and 0.25 μm pore size, respectively). In addition, a comparison between nanofibrous MF membranes and their commercial counterparts from both utility and effectiveness standpoint was conducted and the obtained result indicated the supreme performance of these membranes in comparison with the commercial membranes of the same mean pore size, also with almost double or triple higher flux. [ABSTRACT FROM AUTHOR]

This paper addresses optimization of parameters and measuring setups for in situ computed tomography measurements on marker particle-filled adhesives. The focus of this work was to increase the detail detectability and discriminability between used marker particles and surrounding adhesive compound even for materials with a high X-ray attenuation. Therefore, it is necessary to reduce the effects of artifacts like scattered X-rays and beam hardening, respectively. A key benefit of being able to distinguish different materials clearly improves the correct interpretation of the reconstructed three-dimensional volume significantly, while a reduction of artificial disturbances enhances the possibility to visualize previously overlaid undetected details, e.g. air voids. Performing in situ computed tomography measurements by applying the optimized parameter setups, cavitation formation was observed investigating the particle behavior of specimens modified with glass beads as marker particles under applied load. An achieved bonding enhancement by using a coupling agent as pre-treatment for glass beads was also proven by means of in situ computed tomography. Furthermore, the parameter setups optimized for bulk specimen could be adapted on material combinations, e.g. single-lap shear specimen, by adjusting a few parameters. Additional experiments demonstrate that computed tomography measurements can also be used for analytical purposes, for instance to evaluate the mixing quality of the so-called QUADRO™ or 2C mixers for two-component adhesives. [ABSTRACT FROM AUTHOR]

•MSAF are prepared in batch mode using a home-made foam generating column. •Micro-particles can disperse well in surfactant diluents with the concentration of 0.25 wt.%. •The diffusions of MSAF in the Y direction and Z direction occur simultaneously. •Mathematical model of MSAF flowing in inclined fracture was derived and amended. The goaf is the location where coal mines are most prone to coal spontaneous combustion, 60 % of the spontaneous combustion fire occur in the goaf. The coal has a greater crushing degree at the top of the goaf, where the heat accumulation is not easy to dissipate and mine fires are more likely to occur. In order to prevent coal spontaneous combustion in goaf efficiently and comprehensively, the uniform and dense micro-particles stabilized aqueous foams with the bubble diameter of 350–400 micrometers are prepared in batch mode using a home-made foam generating column with an internal hollow tube. The micro-particles can disperse well in surfactant diluents with the concentration of 0.25 wt.% and have strong wettability with the contact angle of 82.2°. Similar simulation experiments for flow characteristics indicated that the foam fluid does not appear to flow as low as ordinary cement paste, the diffusions in the Y direction and Z direction occur simultaneously, and the whole high fracture of loose gangue heap can be fully accumulated and seeped by foam fluid. Based on the micro-element force analysis of foam fluid in highly inclined fractures, the relationship equations between pressure difference, time, shear force and dynamic viscosity under different fracture dip angles and azimuth angles are derived and amended. The error was compared with the residual measurement points, and the error value is 0.05 %–9.72 %, indicating the amended fitting formula has universal applicability. [ABSTRACT FROM AUTHOR]

• Displacements, microdeformations, temperature and microtemperatures are coupled in a multiphysics process. • Existence, uniqueness and continuous dependence results are shown for the mathematical model. • The plane strain problem is studied by the finite element method. In this study we formulate the mixed initial boundary value problem for a dipolar thermoelastic material whose micro-particles possess microtemperatures. Then this mixed problem is transformed in a Cauchy problem attached to a temporally equation of evolution on a specific Hilbert space, which will be suitably chosen. As such, we will be able to use certain results specific to the theory of the semigroups of contractions in order to obtain the existence and uniqueness of the solution for our problem. The theory of semigroups also facilitates our approach regarding the continuous dependence of the solution upon initial data and loads. Finally, we reduce our model to the isotropic case and perform numerical simulations for the corresponding system of partial differential equations by means of the finite element method. [ABSTRACT FROM AUTHOR]

Low-temperature energy storage system (LTESS) stores the thermal energy from the sun, exhaust gases and waste heat from industries and other sources. Phase changing materials (PCM) are used as the energy storage medium for this system. The advantage of PCM is that it has higher energy storage density, with low volume. The disadvantage of PCM for using as LTESS is that the thermal conductivity of PCM is less and this requires more time period and surface area of contact, for loading and unloading of thermal energy. A solution to this problem can be incorporating graphite micro-particles in the paraffin PCM to improve its thermal conductivity. The heat transfer of LTESS is determined experimentally. Incorporating micro-particle in the PCM has improved the heat transfer of the LTESS. Maxwell–Garnett equation is used to determine the heat transfer of PCM and J-type temperature measuring probe, and sensor apparatus is used to determine the heat transfer experimentally. The encapsulation has increased the heat-retaining ability and storage time by about 40% on average for the flow rates tested. [ABSTRACT FROM AUTHOR]

Doxorubicin and Metformin HCL is a known chemotherapeutic combination that wipes out tumors and prevents their recurrence. However, limited site specificity confines its application. Here we report Doxorubicin and Metformin HCL–loaded guar gum micro-particles prepared by emulsification cum-solidification method. Developed micro-particles were characterized as spherical shape particles with smooth surface and micro size diameter. Encapsulation of drugs in combination was confirmed by their characteristic functional groups (FT-IR), change in phase transition temperature (DSC) and X-ray diffraction pattern (XRD). Particles were observed to be stable at 25 and 5°C. The in vitro Doxorubicin and Metformin HCL release study in simulated gastric (SGF), intestinal (SIF) and colonic fluid (SCF) confirms restricted release in SGF (9.3 and 9.6%, respectively, in 2 h) and SIF (10.8 and 14.7%, respectively, in the next 3 h) and highest release in SCF (about 68 and 73.3%, respectively) in colon. Developed micro-particles showed 78% recovery in tumor volume and considerable improvement in histological changes. X-ray images confirmed good target ability of micro-particles to colon. In conclusion, the specially designed, stable micro-particles are able to target drug combination to colon and improve efficacy by ensuring maximum drug release in colon as compared with Doxorubicin and Metformin HCL combination. [ABSTRACT FROM AUTHOR]

Ascites syndrome (AS) in chickens is associated with profound vascular remodelling and increased pulmonary artery pressure as well as right ventricular hypertrophy. Classical transient receptor potential cation channels (TRPCs) are key regulators of cardiac hypertrophy that act via regulation of calcium influx in mammals. We investigated whether classical transient receptor potential channels in chickens with right ventricular hypertrophy still possess this mechanism for regulating Ca2+ flux. Intravenous injection of cellulose particles was successfully used to induce AS in chickens, and tissues were examined 22 days after treatment. The chickens in the test group showed cardiac hypertrophy with oedema of the cardiac muscle and disruption of myofilaments. The right-to-total ventricle weight ratio (RV/TV), the levels of serum aspartate aminotransferase (AST) and creatine kinase (CK) of the test group were significantly higher than in the control group. Intracellular calcium levels were significantly increased in cardiomyocytes from chickens in the test group. Gene expression of TRPC3, TRPC4, TRPC5, TRPC6 and TRPC7 in heart tissues from the test group showed no significant differences compared with controls. However, TRPC1 protein levels, as well as mRNA levels, were down-regulated in the heart muscle of AS chickens (P < 0.05). Although we observed an increase in calcium concentration, the expression of TRPC1 decreased in cardiac cells. We hypothesized that an increase in intracellular free calcium concentration could inversely regulate calcium channel expression. RESEARCH HIGHLIGHTS Intracellular Ca2+ levels were increased in the myocardium of AS broilers. Expression of TRPC1, which mediates calcium influx, was decreased in the myocardium of AS broilers. The relationship between intracellular Ca2+ levels and expression of TRPC1 requires further study. [ABSTRACT FROM AUTHOR]

It is well known that there are numerous micro-particles and micro-protrusions on electrodes surface in vacuum gaps. The vacuum breakdown mechanisms initiated by the micro-particles and the micro-protrusions have been studied during the vacuum pre-breakdown processes. However, there is no quantitative research on interaction effect between the micro-particles and the field emission electrons based on the non­ideal micro-protrusions in different vacuum gaps. In this paper, by means of a micro-protrusion model based on the fractal theory and the micro-particle dynamic equations, the anode micro-particle characteristics under the bombardment of the field emission electrons in different vacuum gaps are investigated quantitatively. The results show that the bombardment of the field emission electrons has a significant influence on the dynamic characteristics of the micro-particles. There is a close relationship between the vacuum gap and the dynamic characteristics of the micro-particles. With a vacuum gap less than 1.0 mm, the maximum temperature of the micro-particles would eventually reach the boiling point and the evaporation rate would reach 97 kg-m−2·s−1. With a vacuum gap more than 5.0 mm, the maximum temperature would not reach the boiling point and the evaporation rate would decrease to zero. Furthermore, in a vacuum gap more than 5.0 mm, there are more obvious impact phenomena occurred between the cathode and the micro-particle than that in a vacuum gap less than 1.0 mm. The results of this paper may provide some useful information to understand the physical mechanism of vacuum breakdown. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Bacterial infections represent an important drawback in the orthopaedic field, as they can develop either immediately after surgery procedures or after some years. Specifically, in case of implants, they are alleged to be troublesome as their elimination often compels a surgical removal of the infected implant. A possible solution strategy could involve a local coating of the implant by an antibacterial system, which requires to be easily applicable, biocompatible and able to provide the desired release kinetics for the selected antibacterial drug. Thus, this work focusses on a biphasic system made up by a thermo-reversible gel matrix (Poloxamer 407/water system) hosting a dispersed phase (PLGA micro-particles), containing a model antibacterial drug (vancomycin hydrochloride). In order to understand the key parameters ruling the performance of this delivery system, we developed a mathematical model able to discriminate the drug diffusion inside micro-particles and within the gel phase, eventually providing to predict the drug release kinetics. The model reliability was confirmed by fitting to experimental data, proposing as a powerful theoretical approach to design and optimize such in situ delivery systems. [ABSTRACT FROM AUTHOR]

Highlights • Novel GICs containing zirconia nanoparticles and micro-particles were formulated. • EC 50 of the GIC and both zirconia-modified GICs were similar. • Nano-zirconia GIC and GIC had no genotoxic effect to human gingival fibroblast. • Micro-zirconia GIC had higher genotoxicity to cells than nano-zirconia GIC and GIC. Abstract Objective To formulate novel glass ionomer cements (GICs) containing zirconia (nanoparticles (NPs) and micro-particles (MPs)) and investigate the genotoxic effect of their eluates on DNA double-strand breaks of human gingival fibroblasts (HGFs) in vitro using a γ-H2AX fluorescent assay. Methods GIC (control, C), 10%ZrO 2 NPsGIC (T1) and 10%ZrO 2 MPsGIC (T2) were prepared per the manufacturer's instructions (hand-mixed, P/L = 3.4:1 w/w%). Dulbecco's modified Eagle's medium (DMEM) was used as the culture medium for HGFs and for eluate preparation. Eluates were collected from all specimens (n = 5/g, 5 × 2 mm) after 24 h and used for XTT to obtain the EC 50 using Graph Pad Prism4. A γ-H2AX immunofluorescence assay was performed to detect DSBs in HGFs. The mean foci per cells and percentage of free foci cells were statistically compared (one-way ANOVA with Tamhane's post hoc and Chi-square respectively) (p < 0.05). Results (1) EC 50 ranged from 31 to 36%. 5% and 20% eluate concentrations were selected for the genotoxicity test. (2) Cells exposed to eluates from T1 had lower mean foci per cell than cells in T2 and C eluates (p < 0.05). Only cells in T1 at 5% had lower mean foci cell than medium (p < 0.05). (3) T1 and C at both concentration showed a higher, but not significant, percentage of free foci cells than negative control (medium). At 20% eluate concentration T2 had a lower percentage of free foci cells than C (p < 0.05). Significance Nano-zirconia GIC and micro-zirconia GIC were formulated. GIC and both zirconia modified GICs had no genotoxic effect on HGFs in vitro. Further studies related to physical properties should be performed to determine the future clinical applications for these novel nanomaterials. [ABSTRACT FROM AUTHOR]

Abstract The synthetic condition affects the corresponding emission intensity of up-conversion luminescence. Various morphologies of the Gd 6 O 5 F 8 :Yb3+,Tm3+ micro-particles, including size-controlled-hexagonal-prisms, certain-surface-hollow-tubes, football, spheres, ellipsoids, plates, hexagonal-flakes, snowflakes, rods, magneton, and bone, are obtained by adjusting the volume ratios of different alcohols to deionized water and the amount of additions (such as, PVP, EDTA, and EDTA-2Na) in the synthetic system. The amount and species of additions are investigated to be the dominating factors about the hexagonal-prism size and morphological evolution, respectively. Furthermore, corresponding to the up-conversion (UC) spectra of the Gd 6 O 5 F 8 :Yb3+, Tm3+ micro-particles with various morphologies and energy transfer processes between Tm3+ and Yb3+ ions have been investigated and discussed in detail. The results prove that the as-synthesized Gd 6 O 5 F 8 are good host lattices for rare earth blue UC luminescence, which could find potential applications in the fields of solid state light, advanced functional micro-device and anti-fake mark. Highlights • The synthetic condition affects the corresponding emission intensity of up-conversion luminescence. • Various morphologies of the Gd 6 O 5 F 8 :Yb3+,Tm3+ micro-particles, including size-controlled-hexagonal-prisms, certain-surface-hollow-tubes, football, spheres, ellipsoids, plates, hexagonal-flakes, snowflakes, rods, magneton, and bone, are obtained by adjusting the volume ratios of different alcohols to deionized water and the amount of additions (such as, PVP, EDTA, and EDTA-2Na) in the synthetic system. • The amount and species of additions are investigated to be the dominating factors about the hexagonal-prism size and morphological evolution, respectively. • Furthermore, corresponding to the up-conversion (UC) spectra of the Gd 6 O 5 F 8 :Yb3+, Tm3+ micro-particles with various morphologies and energy transfer processes between Tm3+ and Yb3+ ions have been investigated and discussed in detail. • The results prove that the as-synthesized Gd 6 O 5 F 8 are good host lattices for rare earth blue UC luminescence, which could find potential applications in the fields of solid state light, advanced functional micro-device and anti-fake mark. [ABSTRACT FROM AUTHOR]

Abstract The present paper develops model for evaluating the results of high energy micro-particle space debris irradiation of space structures. The closed form solution formulas for determining temperature fields, thermomechanical failure are presented. Fracture of brittle materials under local heat exposure is studied. [ABSTRACT FROM AUTHOR]

The rate of percutaneous absorption of micro-particles is very important due to its effects on human health. In this study, a new approach is proposed to investigate both the lateral and the longitudinal diffusions during the absorption of a micro-particle. The results of the current 2D model are compared with the results of a previous 1D model. According to the results, the influence of lateral diffusion on the rate of percutaneous absorption is important, especially for the lipohilic materials. On the other words, the difference between the results of the two models is more significant, at lower values of the ratio of viable-epidermis-diffusivity to the stratum-corneum-diffusivity (DVE/DSC), or at lower values of the viable epidermis to the stratum corneum partition-coefficient (kVE/kSC). For instance, when DVE/DSC equals to 1 and kVE/kSC is 0.33, for a particle with a radius of 10 µm, the steady-state-molar-flux estimated by the 2D model is 2.37 times greater than that estimated by the 1D model. Hence, the lateral diffusion should be taken into account in the percutaneous absorption of micro-particles. [ABSTRACT FROM AUTHOR]

Contact mechanical seal is a normal technology applied on middle axis of liquid rocket turbo pump, and the kinetic and static seal rings contact low temperature rocket propellant. Copper-graphite (Cu/C) composite as an excellent self-lubrication material was widely used in aerospace industry, this study took Cu/C as ball and bearing steel as disk to investigate the tribology properties, and distilled water were used to simulate the lox tribology performances. This study prepared polytrifluorochloroethylene (PCTFE) micro-particles which were coated on the oxide surfaces of bearing steel disk at temperature of 150 °C. The tribology results showed that the oxide surfaces treated with micro PCTFE particles have lower fiction coefficient and lower wear rate than original disk in water, and the wear morphology revealed that the treated surfaces obviously had less Cu/C composite transfer film than original disk. Meanwhile SEM, EDS, XRD, XPS and light microscope etc revealed that PCTFE micro-particles could associate with the oxide surfaces and caused higher water contact angle, due to the properties of the fluorine-containing composite may cause the good lubrication effect in water. Thus this technology shows great potential to enhance tribological performances for aerospace industry on a large scale. [ABSTRACT FROM AUTHOR]

The aim of our study is to transform the mixed initial boundary value problem considered in the context of micropolar thermoelastic bodies whose micro-particles possess microtemperatures in a temporal evolutionary equation on a Hilbert space. Then, with the help of some results from the theory of semigroups, the existence and the uniqueness of the solution for this equation is proved. Finally, we approach the continuous dependence of the solution upon initial data and loads, also with the help of the semigroup. [ABSTRACT FROM AUTHOR]

This study aims to protect sensitive vitamins D, E, B1 and B2 by co-encapsulation in micro and nanoparticles of water chestnut starch for synergistic effects. The encapsulation efficiency, particle size, thermal properties and molecular configuration & interactions studies were analysed. The nano-sized starch with a particle size of 362 nm showed better encapsulation potential than micro-sized starch having an average particle size of 3.47 μm. The encapsulation efficiency was found to be 35 %, 81.17 %, 83.13 %, & 76.07 % and 46.27 %, 89.29 %, 84.91 %, & 77.60 % for vitamin D, E, B1 and B2 in micro and nano-sized starch, respectively. Fluorescence spectroscopy showed higher intensity for non-covalent interactions within the internal matrix of capsules. The FTIR peak at 877 cm−1 belonging to vitamin ring structures was prominent and confirmed the presence of vitamins in encapsulated powders. The nano starch capsules of vitamins showed better thermal stability with low crystallinity than micro starch capsules of vitamins. The study suggests the use of co-encapsulated vitamins in food fortification/supplementation to overcome the issues related to vitamin deficiencies. • Vitamins D, E, B1 and B2 were encapsulated in micro and nanoparticles of starch. • The encapsulation efficiency for vitamin D was very low. • Size reduction of starch leads to better encapsulation compared to micro starch particles. • Florescence showed non-covalent interactions within the encapsulated molecules. • These capsules can help to overcome vitamin deficiencies in children, women and old people. [ABSTRACT FROM AUTHOR]

Stable and reproducible trapping in air of 1 μ m and 500 nm dielectric particles has been realized using a dual beam optical fiber tweezers with cleaved commercial single mode fibers. The influence of the interference fringes of the two coherent and counter-propagating trapping beam is investigated by controlling the fringe visibility. Optical trapping on a series of up to 10 fringes or trapping on only one to two fringes has been observed in distinct experiments. High axial trapping efficiencies of up to 1 nN μ m −1W−1 is observed. The experimental results are supported by numerical simulations. [ABSTRACT FROM AUTHOR]

Cancer cell-derived micro-particles (MPs) play important regulatory roles on cellular and system levels. These activities are attributed in part to protein factors carried by MPs. However, recruitment strategies for sequestering certain protein factors in MPs are poorly understood. In the current study, using exogenous and endogenously expressed phospholipid-binding probes, we investigated the distribution of membrane phospholipids in MPs as a potential mechanism for electrostatically enriching cationic protein factors in MPs. We detected a significant level of externalised phosphatidylethanolamine (PE) at the outer surface of MPs. This was accompanied, in the inner leaflet of the MP membrane, by a greater density of negatively charged phospholipids, particularly phosphatidylserine (PS). The local enrichment of PS in the inner surface of MPs was correlated with an elevated presence of small GTPases in a polybasic region (PBR)-dependent fashion. By employing a series of RhoA derivatives, including constitutively active and RhoA derivatives lacking a PBR, we could demonstrate that the congregation of RhoA in MPs was dependent on the presence of the PBR. A chimer with the fusion of PBR sequence alone to GFP significantly enhanced GFP localisation in MPs, indicative of a positive contribution of electrostatic interactions in RhoA recruitment to MPs. Using in silico thermodynamic simulations, we characterised the electrostatic interactions between PBR and anionic lipid membrane surface. In summary, the redistribution of membrane phospholipids in MPs has an impact on the local ionic density, and is likely a contributing factor in the electrostatic recruitment of membrane-associated proteins to MPs in a PBR-dependent fashion.

A new model is proposed for production of fine particles of Nabutemon by rapid expansion of supercritical solutions (RESS). A mathematical model is used for prediction of particle size and particle size distribution of RESS produced particles. In this model the effect of various operating parameters such as pressure and temperature of extraction and temperature and pressure of expansion on the characteristics of products were studied. The calculation results showed good agreement between the calculation results and the experimental data for Nabutemon particles.

This short communication presents a simple method of preparation of thin-metal nano-platelets utilizing metal sputtering and lift-off photolithography. The method offers complete control over size, shape and properties of nano-platelets of sub-micrometer thickness. Platelets with a thickness of 50⁻200 nm and with defined arbitrary shapes and sizes in the range of 15⁻300 μm were prepared from single or multiple metal layers by magnetron sputtering. Deposition of different metals in layers enabled fabrication of bi- or tri-metallic platelets with a magnetic core and differently composed surfaces. Highly reflective nano-platelets with a magnetic core allowed manipulation by magnetic fields, while different metallic surfaces served for functionalization by selected molecules. Submicron thin nano-platelets are extremely light (e.g., ~20 ng for a 100 μm × 100 μm × 0.1 μm gold nano-platelet) so that they can be attached to surfaces by only a few chemical bonds. At the same time their area is sufficiently large for simple optical recognition of their shape which is intended to label various characteristics depending on the specific surface functionalization of the given shape.

In the present study chicken feathers were hydrolyzed by chemical treatment in alkaline conditions. The pH value of feather hydrolyzed solution was amended accordingly the iso- electric precipitation. Two types of keratin microparticles KM1, KM2 were synthesized under acidic conditions at 3.5 and 5.5 pH respectively. The synthesized keratin microparticles possessed uniform and round surface by scanning electron microscopy (SEM). The thermal degradation of microparticles were examined by thermogravimetry (TGA). Fourier transform infrared spectroscopy (FTIR) revealed that the extracted keratin retained the most of protein backbone. The microparticles were screened for their in vitro anticancer activities by SRB bioassay towards HeLa, SK-OV-3 and A549 cancer cell lines. Futhermore, their cytotoxicity towards healthy cell lines was analyzed having Malin Darby canine kidney (MDCK) cell lines along with in vitro antioxidant activity using DPPH and ABTS methods KM1 and KM2 showed 200.31 ± 1.01 and 139.73 ± 0.94, 214.16 ± 0.29 and 153.92 ± 0.61, 328.92 ± 3.46 and 200.33 ± 2.48 μg/mL of IC 50 levels against HeLa, SK-OV-3, and A549 cell lines, respectively. Moreover, KM1 and KM2 demonstrated significant antioxidant potency with IC 50 levels 13.15 and 9.02 μg/mL as well as 8.96 and 5.60 μg/mL in DPPH and ABTS radical scavenging bioassay, respectively. [ABSTRACT FROM AUTHOR]

This research work explores the surface chemistry and drug-polymer interaction in the manufactured controlled release micro-particles. Isoniazid (INH) was used as a model anti-tubercular drug while Eudragit® S100 (S100), Eudragit® L100-55 based co-processed Acryl EZE (EZE) and Ethylcellulose ECN10 (ECN10) were used as polymeric carriers. INH containing micro-particles were prepared using a mini spray dryer B-290 (Buchi, Switzerland). The drug polymer ratios were optimized at 1:1 and 1:3 to evaluate the effect of polymers on the release of the drug from the micro-particles. Solid state characterization via SEM and particle size analysis of the manufactured micro-particles showed densely aggregated spherical particles with a mean diameter < 10 μm. The advanced surface analysis via EDS revealed a homogenous drug distribution on the spray dried micro-particles. The physico-chemical characterization carried out by using DSC and XRPD showed an increase in the amorphicity of the drug during the spray drying process while the chemical elemental analysis via XPS revealed a strong intermolecular interaction between the amine group of the drug and the carboxyl group of the polymers. As expected, the in vitro dissolution study showed a slow release pattern for the highly water soluble drug INH in acidic media (pH 1.2) for the first 2 h followed by a burst release upon changing the pH to 6.8. It was concluded that emerging spray drying processing can be used as a valuable tool to encapsulate drug for controlled release dosage forms by means of facilitating a possible drug/polymer interaction as outlined by novel XPS analysis. [ABSTRACT FROM AUTHOR]