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Environmental solid waste bioremediation is a method of treating contaminated solid waste that involves changing ecological conditions to foster the growth of a broad spectrum of microorganisms and the destruction of the target contaminants. A wide range of microorganisms creates metabolites that may break down and change solid waste-based pollution to various value-added molecules. Diverse bioremediation technologies, their limitations, and the procedure involve recycling solid waste materials from the environment. The existing environmental solid waste disposal services are insufficient and must be upgraded with more lucrative recovery, recycling, and reuse technologies to decrease the enormous expenditures in treatment procedures. Bioremediation of solid waste eliminates the toxic components. It restores the site with the advent of potential microbial communities towards solid waste valorization utilizing agriculture solid waste, organic food waste, plastic solid waste, and multiple industrial solid wastes.Bioengineering on diverse ranges of microbial regimes has accelerated to provide extra momentum toward solid waste recycling and valorization. This approach increases the activity of bioremediating microbes in the commercial development of waste treatment techniques and increases the cost-effective valuable product generation. This framework facilitates collaboration between solid waste and utilities. It can aid in establishing a long-term management strategy for recycling development with the advent of a broad spectrum of potential microbial assemblages, increasing solid waste contamination tolerance efficiency and solid waste degradability. The current literature survey extensively summarises solid waste remediation valorization using a broad spectrum of microbial assemblages with special emphasis on bioengineering-based acceleration. This approach is to attain sustainable environmental management and value-added biomolecule generation.

This study provides insights into the influence of sucrose (a water-soluble additive) on microstructure evolution in the transition region and steady-state region in ice-templated Li4Ti5O12 materials. A scanning electron microscope was employed for the two-dimensional characterization of microstructure in the transition region. Sucrose reduced the height of the transition region, caused an early alignment of ice lamellae toward temperature gradient direction, and resulted in a fine, dendritic microstructure. The overall microstructure development in the transition region was markedly different with and without sucrose. The differences were rationalized based on thermal conductivity, constitutional supercooling, and instability of the planar interface. Three-dimensional characterization of the steady-state region using X-ray computed tomography revealed that sucrose caused increased branching of the primary ice dendrites through tip splitting. A majority of the secondary dendrites turned into neighboring primary dendrites, enhancing pore path complexity. Diffusion simulations were performed to quantify pore tortuosity, which increased with sucrose content.

This paper describes novel soft dielectric elastomer composites that exhibits interesting features from the perspective of dielectric-elastomer transducer development, with enhanced actuation performance under an applied electric field that are potentially suitable for actuator applications. Materials solutions described are a combination of ceramic BN platelets, used at low loading levels, and a plasticizer (Naphthenic Oil) in a polymer matrix and synergistic effects between them that leads to enhancement in actuation strain by as high as 328% under applied electric field. Such functional dielectric composites would alleviate several issues such as size, functionality, and performance for many real-world actuator applications.

The enormous capability of microalgae for biomass production and co-products has recently been widely researched from a range of research approaches. Microalgae biomass has been discovered as a suitable feedstock for biofuel generation in the third generation. Although they may easily be cultivated in the laboratory, commercial cultivation involves several important considerations, including design, expense, contamination risk, and hygiene. This paper reviews some conventional microalgal cultivation methods along with some harvesting techniques. A short note on the disadvantages of conventional microalgal biofilm cultivation and the need for advanced cultivation techniques are also listed. Further, it highlights some of the modern techniques used for the cultivation of biofilm-based microalgae. It also gives brief information on the various factors affecting the formation of microalgal biofilm. A detailed description of the application of microalgal biofilm concerning biofuel generation is also reviewed. Graphical abstract

This study revealed that the mass ratio of large anisometric particles (platelets) to ultrafine, equiaxed particles strongly influences dynamic and quasistatic compressive response and the process of damage evolution in ice-templated alumina materials. The improved sinterability between particles of significantly dissimilar size and morphology enabled the utilization of a high mass ratio of the particles in harnessing a markedly enhanced level of strength in highly porous ice-templated ceramics. The high volume fraction of platelets increased lamellar bridge density and resulted in dendritic morphology as opposed to lamellar morphology without platelets. All the materials showed strain rate-sensitivity, where strength increased with strain rate. Materials with highly dendritic morphology exhibited the best performance in terms of maximum strength and energy absorption capacity, and the performance improved from quasistatic to dynamic regime. Direct observation of the process of damage evolution revealed the effects of both strain rate and ratio of platelets to ultrafine particles.

The central focus of this study is to investigate the influence of microstructure and direction of impact (relative to the growth direction of ice crystals) on the impact behavior of ice-templated sintered alumina materials and understand the relationship between dynamic compressive strength and impact response. All materials were fabricated using alumina suspensions of the same solid loading but at three different freezing front velocity (FFV) regimes; very-high FFV, moderately-high FFV, and low FFV. Lamella wall thickness, pore size, and pore aspect ratio decreased, and wall connectivity increased with FFV. Materials also exhibited a structural gradient along the growth direction of ice crystals. As the templated microstructure became finer with FFV, the impact resistance of the materials increased, and radius of damage crater, depth-of-penetration, and mass loss decreased. Materials also exhibited radial cracking, and the materials fabricated at very-high FFV showed a greater propensity for radial cracking for impact along the growth direction. The impact process evolved in three phases; penetration phase, dwell phase and rebound phase. Analysis of high-speed videos revealed that modifying the microstructure affected not only the impact resistance but also the duration of these phases. Variation in microstructure caused a change in the mechanism of damage evolution during impact. Dynamic compressive strength increased with FFV, and the results revealed a direct relationship between impact response and strength. For both impact and dynamic compression, energy absorption per unit volume increased with FFV, further reinforcing the relationship between impact behavior and the dynamic compressive response of ice-templated materials.

The current study investigated the effects of porosity, microstructure, and strain rate regime on the damage evolution and failure behavior under uniaxial compressive loading conditions in ice-templated alumina materials. The compressive response was investigated in dynamic and quasistatic loading regimes. Microstructural analysis revealed that in the high porosity regime, morphology was lamellar. In the lower porosity materials processed at higher freezing front velocities (FFVs), morphology was dendritic but transitioned to lamellar structure with the decreasing FFV. Ice-templated materials with higher porosity exhibited progressive crushing type damage evolution, irrespective of the FFV and strain rate regime. The origin of progressive crushing type failure was observed to be the absence of macroscopic crack evolution in the vicinity of peak stress, and subsequent to peak stress damage evolved only in the form of minimal fragmentation that gradually increased with the increasing strain. However, at comparable strain, the extent of dynamic damage was less compared to quasistatic damage, which suggests enhanced resistance to brittle fracture at high-strain rates. With the decreasing porosity damage evolution process changed, particularly under quasistatic loading in the materials processed at higher FFVs. Up to peak stress materials were intact, whereas upon reaching peak stress significant damage evolved causing complete loss of compressive load-bearing capacity. Whereas, damage evolution under dynamic loading in the vicinity of peak stress was significantly limited and damage accumulated progressively with the increasing strain, which strongly suggests greater structural stability in the ice-templated porous ceramic materials at high-strain rates.

This study investigated the compressive response of ice-templated composites and provides an understanding of their mechanical behavior based on the properties of templated ceramic and epoxy. Results suggested a dependence of properties on the microstructure of the templated porous ceramic, whereas more interestingly composites exhibited catastrophic and progressive types of failure. Compressive strength was found to be markedly greater relative to the strength of templated ceramic and polymer, and irrespective of the failure type, strength was greatly enhanced under dynamic loading relative to quasistatic loading. Compressive strength was also calculated based on the rule of mixtures and mode of failure in ice-templated ceramic. The analysis suggested that the axial mode of failure was not dominant in composites, and failures resulted from the fracture of lamella walls, possibly due to elastic instability. Fragments of the composite specimens were analyzed using scanning electron microscopy to study the fracture characteristics and rationalize the catastrophic and progressive types of failure.

This paper describes nonlinear dielectric composite passive components on flexible metallic substrates for transient protection of electronic devices, most notably against electrostatic discharge (ESD) and electrical overstress (EOS) conditions. In this case, the passive device comprises a polymer composite that contains nonlinear inorganic fillers, an electric field switchable dielectric ceramic Calcium Copper Titanate (CaCu3Ti4O12, CCT), in a metal insulator metal (MIM) configuration. Compatibility with PCB (printed circuit board) in line processing is demonstrated since the fabrication process described is a relatively low temperature process. Advantageously, the construction of such components are such that they can be embedded within a PCB (printed circuit board), thereby allowing miniaturization of the circuit design and can potentially be adopted in an industrial roll to roll manufacturing process. The dielectric characteristics of the CCT filler polymer composites are compared with well-known high dielectric constant Barium Titanate filler polymer composites for capacitor applications. Theoretical models based on effective medium theory are used to predict the dielectric properties of the CCT epoxy composites as a function of filler loading fractions. Maxwell Garnett model was found to provide the best fit to experimental data.

The present work deals with the compensation of third-order dispersion (TOD) in view of parabolic pulse (PP) generation in standard normal dispersion-decreasing fiber (NDDF) links by using phase modulator (PM) at certain position within the link. Since the inherent TOD in the fiber leads to an asymmetric pulse shape and thus degrades the PP formation, there is a strong requirement to minimize the TOD within the fiber link. It is seen that insertion of PM at the estimated critical length reduces misfit parameter satisfactorily at the output end and an equivalent PP is regenerated. A three-stage cascaded system comprising the first section of NDDF, dispersion-shifted fiber (DSF) and a normal dispersion fiber (NDF) may also be useful to mitigate TOD by showing the equivalent performance as that obtained by employing PM in the previous case.

Three different silica based normal dispersion fibers are designed to identify the best possible one for efficient parabolic pulse generation. Two of them resemble commonly used single core fibers and optimized in such a way that one has lower dispersion and nonlinear coefficient whereas the other possesses higher dispersion and lower nonlinearity. A silica based multi-cladded highly nonlinear fiber (ND-HNLF) is designed as well by successfully restricting its effective area to a very lower value. The comparative analysis among the three fibers suggests that the ND-HNLF would be the best choice for fiber optic manufacturers for parabolic similariton formation due to its smaller optimum length, no effect of higher order dispersion, high nonlinearity and less input power requirement. From our proposed ND-HNLF, a highly nonlinear dispersion decreasing fiber (HN-NDDF) is also designed and optimized by properly varying different fiber parameters as a function of fiber length. Our study also reveals that the HN-NDDF with a typical property of virtual gain would be beneficial for producing parabolic self-similar pulses at smaller optimum lengths with adequate spectral broadening in comparison to that of ND-HNLF.

In order to supplement the need for alternative energy resources within the near future, enhancing the production of biohydrogen with immobilized Clostridium beijerinckii NCIMB8052 was investigated. Magnetite nanoparticles were functionalized, with chitosan and alginic acid polyelectrolytes using a layer-by-layer method, to promote bacterial attachment. Cultivating C. beijerinckii with these nanoparticles resulted in a shorter lag growth phase and increased total biohydrogen production within 100-ml, 250-ml and 3.6-L reactors compared with freely suspended organisms. The greatest hydrogen yield was obtained in the 250-ml reactor with a value of 2.1 ± 0.7 mol H2/mol glucose, corresponding to substrate conversion and energy conversion efficiencies of 52 ± 18 and 10 ± 3 %, respectively. The hydrogen yields obtained using the immobilized bacteria are comparable to values found in literature. However, to make this process viable, further improvements are required to increase the substrate and energy conversion efficiencies.

To identify the best possible normally dispersive optical fibers (NDF) in view of efficient triangular pulse (TP) generation, the optimization of several passive NDFs are reported in this work. The study shows that TPs, which sustain over a reasonably good fiber length, can be generated at shorter length when higher values of dispersion and nonlinearity are considered. A suitable NDF with high value of dispersion and nonlinearity is chosen and renamed as normally dispersive highly nonlinear fiber (ND-HNLF). The fiber parameters and pulse conditions are optimized here in such a way that the pulse maintains its triangular shape throughout a longer length in transient state. A detail analysis is performed on generation and stability of triangular pulses through the ND-HNLFs in absence and in presence of gain. When compared, the ND-HNLF with gain is found to be preferable due to their lower input power requirement and lesser broadening of the output triangular pulses whereas passive ND-HNLF performs better in terms of formation of TPs at shorter length and sustainability of those pulses over moderately larger fiber length. It is also shown that the suggested fibers, competent enough to generate stable TPs can be potentially applied in the area of optical signal doubling and a new fiber based approach is mentioned as well for saw-tooth pulse formation.

The present work deals with the performances of straight and bent active normal dispersion decreasing fibers (NDDFs) to create parabolic pulses. Since these optical fibers are generally kept in the form of fiber rolls, they may suffer from unavoidable bend losses. For the NDDFs, the core radius and hence transverse field distribution inevitably change along the fiber length; thereby bend loss is no longer an invariable quantity throughout the NDDF length. The spatial variation of bend loss for a parabolic index NDDF is incorporated for the first time to investigate the effect of bend loss analytically and numerically on parabolic pulse generation. It is illustrated that suitable choice of relative refractive index difference and bend radius of curvature of the fibers would lead to parabolic pulse formation by a bent NDDF. The comparative study on the straight and bent NDDFs will be helpful for the fiber optic manufacturers to design and fabricate NDDFs with proper choice of optimized parameters and index differences so that parabolic pulses can be generated even under the influence of practically unavoidable bending.

The purpose of this study was to prepare low molecular weight alginic acid (LMWA) nanoparticles by cation-induced, controlled gelification of depolymerized alginic acid for effective drug delivery to drug resistant bacteria. The depolymerization reaction was performed using potassium persulfate oxidation at an optimized condition. The optimized conditions for depolymerization were anticipated to be 37°C, pH 4, 2 days reaction time, and a 0.075 M concentration of potassium persulphate containing 0.001 M silver nitrate in the final reaction mixture. Gel permeation chromatography showed depolymerized alginic acid had an average molecular weight of 20.95 ± 0.49 kDa. Depolymerized alginic acid was also characterized for its structural integrity by X-ray diffraction, nuclear magnetic resonance, and Fourier transform spectroscopy. Depolymerized alginic acid was used to prepare low molecular weight nanoparticles with a particle size of 54 ± 0.41 nm, and a zetapotential of −32.2 ± 3.91 mV. The nanoparicles were then subjected to tetracycline loading. In vitro drug loading and drug release efficiencies after 100 h were determined to be 66.56 ± 1.88 and 61.8 ± 0.141%, respectively. Finally, the minimal inhibitory concentration and a putative mode of action for the tetracycline nanoparticles were determined using tetracycline resistant bacteria, Escherichia coli XL-1.

Study was focused to effectively suppress the agglutinability of human A and B type erythrocyte by concerted chemical oxidation approach. Consequently some major bio-physiological consequences of human erythrocytes were analyzed.Concerted chemical oxidation of human A and B type erythrocyte were done by potassium permanganate (KMnO(4)) in presence of ethylene diamine tetra-acetic acid (EDTA). All the chemical reactions were carried out at 37°C temperature and pH 7.4 in phosphate buffer. Finally, suppression of agglutinability were determined by using anti-A and anti-B antisera.A marked suppression in agglutinability was observed after chemical treatment on human A and B type erythrocytes in vitro. Effective suppression of agglutinability was observed in 0.57 mM concentration of KMnO(4) in presence of 0.9 mM EDTA at optimum condition.Results showed that KMnO(4)-EDTA concerted action is feasible. The future work is directed towards the universal human erythrocytes preparation from A and B type human erythrocytes.

Dramatically rising oil prices and increasing awareness of the dire environmental consequences of fossil fuel use, including startling effects of climate change, are refocusing attention worldwide on the search for alternative fuels. Hydrogen is poised to become an important future energy carrier. Renewable hydrogen production is pivotal in making it a truly sustainable replacement for fossil fuels, and for realizing its full potential in reducing greenhouse gas emissions. One attractive option is to produce hydrogen through microbial fermentation. This process would use readily available wastes as well as presently unutilized bioresources, including enormous supplies of agricultural and forestry wastes. These potential energy sources are currently not well exploited, and in addition, pose environmental problems. However, fuels are relatively low value products, placing severe constraints on any production process. Therefore, means must be sought to maximize yields and rates of hydrogen production while at the same time minimizing energy and capital inputs to the bioprocess. Here we review the various attributes of the characterized hydrogen producing bacteria as well as the preparation and properties of mixed microflora that have been shown to convert various substrates to hydrogen. Factors affecting yields and rates are highlighted and some avenues for increasing these parameters are explored. On the engineering side, we review the potential waste pre-treatment technologies and discuss the relevant bioprocess parameters, possible reactor configurations, including emerging technologies, and how engineering design-directed research might provide insight into the exploitation of the significant energy potential of biomass resources.

Genetically encoded antibiotic peptides are evolutionarily ancient and widespread effector molecules of immune defence. Mammalian defensins, one subset of such peptides, have been implicated in the antimicrobial defence capacity of phagocytic leukocytes and various epithelial cells, but direct evidence of the magnitude of their in vivo effects have not been clearly demonstrated. Paneth cells, specialized epithelia of the small intestinal crypt, secrete abundant alpha-defensins and other antimicrobial polypeptides including human defensin 5 (HD-5; also known as DEFA5). Although antibiotic activity of HD-5 has been demonstrated in vitro, functional studies of HD-5 biology have been limited by the lack of in vivo models. To study the in vivo role of HD-5, we developed a transgenic mouse model using a 2.9-kilobase HD-5 minigene containing two HD-5 exons and 1.4 kilobases of 5'-flanking sequence. Here we show that HD-5 expression in these mice is specific to Paneth cells and reflects endogenous enteric defensin gene expression. The storage and processing of transgenic HD-5 also matches that observed in humans. HD-5 transgenic mice were markedly resistant to oral challenge with virulent Salmonella typhimurium. These findings provide support for a critical in vivo role of epithelial-derived defensins in mammalian host defence.

Paneth cells (PCs) were described over a century ago as granulated cells located at the base of small intestinal crypts, the 'crypts of Lieberkühn.' Various histochemical staining procedures were developed that identified PCs based on their distinctive granule-staining pattern. Early on, PCs were proposed to perform a specialized function other than absorption of digested nutrients, the predominant task of the small intestinal epithelium. Since then, many constituents of the PC granules have been biochemically characterized. The presence of various granule-associated antimicrobial substances and their release upon microbial challenge suggest that PCs function as specialized defense cells in the small intestine. Altered resistance to microbial infection in animal models with disrupted or augmented PC function provides further support for the host defense role of PCs. Other PC components suggest that PCs may also participate in the regulation of lumenal ionic composition, crypt development, digestion, and intestinal inflammation.

Co : Al2O3nanocermets are synthesized by co-reducing Co2+-cations dispersed in a mesoporous AlO(OH) · αH2O matrix (amorphous) in a pure H2atmosphere at 850–1150 K. The dispersed Co2+-cations in pores co-reduce to separated Co-particles of controlled size, as small as 50 nm, encapsulated in thin Al2O3films, which are formed in-situ by molecular decomposition of the matrix, 2AlO(OH) · αH2O → Al2O3+ (2α + 1)H2O. The Al2O3film which coats Co-particles has an amorphous structure. This is possible only if it is extremely thin limited to a thickness of t< 2rc, with rc∼ 1.9 nm the critical size of its nucleation and growth into a stable crystallite. The thin Al2O3surface film supports the formation and existence of Co-particles in a modified FCC or BCC crystal structure. As a result, unusually, large crystallites of an average 100 nm diameter could be observed. Normally, such large particles of pure Co-metal exist in an HCP structure which undergoes a reversible martensitic transformation to FCC structure at 695 K. The results are analyzed and discussed in terms of microstructure, x-ray diffraction and XPS studies of nanocermets prepared under selected conditions.

Residual strains in ferroelectrics are known to adversely affect the material properties by aggravating crack growth and fatigue degradation. The primary cause for residual strains is strain incompatibility between different microstructural entities. For example, it was shown in polycrystalline ferroelectrics that residual strains are caused due to incompatibility between the electric-field-induced strains in grains with different crystallographic orientations. However, similar characterization of cause-effect in multidomain ferroelectric single crystals is lacking. In this article, we report on the development of plastic residual strains in [111]-oriented domain engineered BaTiO(3) single crystals. These internal strains are created due to strain incompatibility across 90° domain walls between the differently oriented domains. The average residual strains over a large crystal volume measured by in situ neutron diffraction is comparable to previous X-ray measurements of localized strains near domain boundaries, but are an order of magnitude lower than electric-field-induced residual strains in polycrystalline ferroelectrics.

Prior research has investigated the influence of decision maker characteristics on decision choice. This research examines the effect two personality traits of taxpayers, attitude towards risk and ethical standards, on intentional noncompliance. A taxpayer who is more (less) ethical will have lower (greater) intentional noncompliance, while a taxpayer who is more (less) risk averse will have lower (greater) intentional noncompliance. However, this study also found significant correlation between risk attitudes and ethical standards. This is because tax evasion is not just a gamble which can be explained by merely considering the risk variable. To understand tax evasive behavior better requires incorporation of noneconomic factors in the analysis, such as ethical standards, although risk attitudes may be an important explanatory factor. The current research suggests that individuals with lower ethical standards will have more intentional noncompliance. However, since ethical standards are correlated with attitude toward risk, the Internal Revenue Service (IRS) can partially overcome the influence of ethics by making the tax audit environment more uncertain. Thus, the research results justify the decision of the IRS not to release all its audit parameters because it makes the audit environment less uncertain.