214 research outputs found
State of the mineral component of rat bone tissue during hypokinesia and the recovery period
Experiments were conducted on young growing rats. Hypokinesia lasting from 20 to 200 days caused retarded gain in weight and volume of the femur and delayed development of the cortical layer of the diaphysis. In contrast, the density of the cortical layer of the femoral diaphysis increased due to elevation of the mineral saturation of the bone tissue microstructures. Incorporation of Ca into the bone tissue in hypokinesia had a tendency to reduce. Partial normalization of the bone tissue mineral component occurred during a 20 day recovery period following hypokinesia
Pathomorphological Changes in Poultry Pasteurellios, Pullorosis and Colibacteriosis Diseases
The organism of chicken infected with individual pathogens exhibits relatively simple patho-anatomical modifications in the presence of two or three separate bacterial pathogens. Because it is highly challenging to differentiate between mixed bacterial infections based just on clinical symptoms, pathologoanatomical examination and distinction are preferred. These disorders will be accurately diagnosed promptly and without delay if the pathologo-anatomical investigations are properly examined, and preventive measures will be consistently applied
Application of aquatic plants for the treatment of selenium-rich mining wastewater and production of renewable fuels and petrochemicals
Aquatic plants aggressively colonising wetlands are widely used for the biosorption of the soluble contaminants from wastewater and represent an attractive feedstock for biofuel production. Three common Australian aquatic plants, duckweed (Landoltia punctata), elodea, (Elodea canadensis) and water clover (Marsilea quadrifolia), colonizing different depths of wetlands were tested for their ability to treat the selenium-rich mining wastewater and for their potential for production of petrochemicals. The results showed that these plants could be effective at biofiltration of selenium and heavy metals from mining wastewater accumulating them in their fast growing biomass. Along with production of bio-gas and bio-solid components, pyrolysis of these plants produced a range of liquid petrochemicals including straight-chain C14-C20 alkanes, which can be directly used as a diesel fuel supplement or as a glycerine-free component of biodiesel. Other identified bio-oil components can be converted into petrochemicals using existing techniques such as catalytic hydrodeoxygenation. A dual application of aquatic plants for wastewater treatment and production of value-added chemicals offers an ecologically friendly and cost-effective solution for water pollution problems and renewable energy production
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Sustainable hydrogen production
This report describes the Sustainable Hydrogen Production research conducted at the Florida Solar Energy Center (FSEC) for the past year. The report presents the work done on the following four tasks: Task 1--production of hydrogen by photovoltaic-powered electrolysis; Task 2--solar photocatalytic hydrogen production from water using a dual-bed photosystem; Task 3--development of solid electrolytes for water electrolysis at intermediate temperatures; and Task 4--production of hydrogen by thermocatalytic cracking of natural gas. For each task, this report presents a summary, introduction/description of project, and results
Dual application of duckweed and azolla plants for wastewater treatment and renewable fuels and petrochemicals production
Shortages in fresh water supplies today affects more than 1 billion people worldwide. Phytoremediation strategies, based on the abilities of aquatic plants to recycle nutrients offer an attractive solution for the bioremediation of water pollution and represents one of the most globally researched issues. The subsequent application of the biomass from the remediation for the production of fuels and petrochemicals offers an ecologically friendly and cost-effective solution for water pollution problems and production of value-added products. Results: In this paper, the feasibility of the dual application of duckweed and azolla aquatic plants for wastewater treatment and production of renewable fuels and petrochemicals is explored. The differences in absorption rates of the key wastewater nutrients, ammonium and phosphorus by these aquatic macrophytes were used as the basis for optimization of the composition of wastewater effluents. Analysis of pyrolysis products showed that azolla and algae produce a similar range of bio-oils that contain a large spectrum of petrochemicals including straight-chain C10-C21 alkanes, which can be directly used as diesel fuel supplement, or a glycerin-free component of biodiesel. Pyrolysis of duckweed produces a different range of bio-oil components that can potentially be used for the production of "green" gasoline and diesel fuel using existing techniques, such as catalytic hydrodeoxygenation. Conclusions: Differences in absorption rates of the key wastewater nutrients, ammonium and phosphorus by different aquatic macrophytes can be used for optimization of composition of wastewater effluents. The generated data suggest that the composition of the petrochemicals can be modified in a targeted fashion, not only by using different species, but also by changing the source plants' metabolic profile, by exposing them to different abiotic or biotic stresses
Fungal-assisted algal flocculation: Application in wastewater treatment and biofuel production
Background The microalgal-based industries are facing a number of important challenges that in turn affect their economic viability. Arguably the most important of these are associated with the high costs of harvesting and dewatering of the microalgal cells, the costs and sustainability of nutrient supplies and costly methods for large scale oil extraction. Existing harvesting technologies, which can account for up to 50% of the total cost, are not economically feasible because of either requiring too much energy or the addition of chemicals. Fungal-assisted flocculation is currently receiving increased attention because of its high harvesting efficiency. Moreover, some of fungal and microalgal strains are well known for their ability to treat wastewater, generating biomass which represents a renewable and sustainable feedstock for bioenergy production. Results We screened 33 fungal strains, isolated from compost, straws and soil for their lipid content and flocculation efficiencies against representatives of microalgae commercially used for biodiesel production, namely the heterotrophic freshwater microalgae Chlorella protothecoides and the marine microalgae Tetraselmis suecica. Lipid levels and composition were analyzed in fungal-algal pellets grown on media containing alternative carbon, nitrogen and phosphorus sources from wheat straw and swine wastewater, respectively. The biomass of fungal-algal pellets grown on swine wastewater was used as feedstock for the production of value-added chemicals, biogas, bio-solids and liquid petrochemicals through pyrolysis. Co-cultivation of microalgae and filamentous fungus increased total biomass production, lipid yield and wastewater bioremediation efficiency. Conclusion Fungal-assisted microalgal flocculation shows significant potential for solving the major challenges facing the commercialization of microalgal biotechnology, namely (i) the efficient and cost-effective harvesting of freshwater and seawater algal strains; (ii) enhancement of total oil production and optimization of its composition; (iii) nutrient supply through recovering of the primary nutrients, nitrogen and phosphates and microelements from wastewater. The biomass generated was thermochemically converted into biogas, bio-solids and a range of liquid petrochemicals including straight-chain C12 to C21 alkanes which can be directly used as a glycerine-free component of biodiesel. Pyrolysis represents an efficient alternative strategy for biofuel production from species with tough cell walls such as fungi and fungal-algal pellets
Theory of shot noise in space-charge limited diffusive conduction regime
As is well known, the fluctuations from a stable stationary nonequilibrium
state are described by a linearized nonhomogeneous Boltzmann-Langevin equation.
The stationary state itself may be described by a nonlinear Boltzmann equation.
The ways of its linearization sometimes seem to be not unique. We argue that
there is actually a unique way to obtain a linear equation for the
fluctuations. In the present paper we treat as an example an analytical theory
of nonequilibrium shot noise in a diffusive conductor under the space charge
limited regime. Our approach is compared with that of Schomerus, Mishchenko and
Beenakker [Phys. Rev. B 60, 5839 (1999)]. We find some difference between the
present theory and the approach of their paper and discuss a possible origin of
the difference. We believe that it is related to the fundamentals of the theory
of fluctuation phenomena in a nonequilibrium electron gas.Comment: 17 pages, no figure
Studying of 2D Titanium Carbide Structure by Raman Spectroscopy after Heat Treatment in Argon and Hydrogen Atmospheres
Here in we show the effect of heat treatment of two dimensional layered titanium carbide structure (Ti3C2Tx), so called MXene. As prepared MXene has functional groups -OH, -F, -Cl. In order to remove the functional groups we heat treated the MXene in Ar (with 0.01% O2) and H2 (with 0.01% H2O) atmospheres. We discovered the significant decrease in the amount of functional groups (-F and -Cl) and increase in the -O content, which refers to the oxidation of the material. Also we determined the optimal regime for Raman spectroscopy in order to avoid any changes in the structure of the material. We revealed that titanium carbide changes its structure at 700 °C and 900 °C into two different titanium dioxide modifications like rutile and anatase in Ar (with 0.01% O2) atmosphere. Also there are small changes occurred in Ti3C2Tx structure and formation of amorphous carbon after 700 °C treatment in H2 (with 0.01% H2O) atmosphere and formation of TiO2 (rutile) at 900 °C. Energydispersive X-ray spectroscopy (EDX) revealed the reduction of functional groups at 700 °C in both atmospheres and total disappearance of –F and –Cl and increasing the
oxygen at 900 °C. The huge increase of oxygen by atomic percent, can be explained by the initial oxygen content in argon and hydrogen gases
Comparative dynamics of the level of cortisol during general anesthesia with the use of the laryngial mask and intubation of the trachea in patients operated for nodular thyroid gland formations
The results of the examination of the cortisol content in the blood during general anesthesia in 60 patients operated on for thyroid nodular formations are analyzed. The first group (main group) -40 patients in whom ALV was carried out using the laryngial mask (LM); The 2nd (control) group - Ventilation was performed with intubation of the trachea (IT). The level of cortisol in the blood in both groups was determined in 4 stages: 1- the day before the operation; 2- when applying LM and IT; 3- with stromectomy and 4 th stage - with the application of the last sutures to the wound of the neck. The results of the studies showed that in both methods of ventilation the sympathetic-adrenal system is adequately protected, however, anesthesia with LM causes less stress response; so if during the imposition of LM the level of cortisol increased by 33% from the initial index, then in the second group (intubation of the trachea) this reached up to 35.7% (P <0.05). Similar proportions were more or less characteristic in the 4th stage. However, during the peak of the operation (stage 3 of the examination) in both groups, the level of cortisol in the blood was approaching the baseline, which proved the adequacy of anesthesia in both groups. In addition, the use of LM in the replacement of tracheal intubation, along with the least response of the stressful response of the body, can reduce the occurrence of unwanted symptoms in the postoperative period in the upper respiratory tract.Анализируется результаты обследования содержание кортизола в крови в течении общей анестезии у 60 больных , оперированных по поводу узловыми образованиями щитовидной железы, которые распределены в две группы: первая (основная) группа -40 больных у которых ИВЛ проводилась с использованием ларенгиальной маски (ЛМ); 2-я (контрольная) группа – ИВЛ осуществлен с интубацией трахеи (ИТ).Уровень кортизола в крови в обеих группах определялись в 4 этапа: 1- за день до операции; 2- при наложении ЛМ и ИТ; 3- при струмэктомии и 4-й этап – при наложении последних швов на рану шеи. Результаты проведенных исследований доказали, что в обеих методах вентиляции легких в достаточном уровне оберегается симпатико-адренальовый система , однако проведение анестезии с ЛМ вызывает меньше стрессового ответа ; так если во время наложения ЛМ уровень кортизола повышалась на 33% от исходного показателя, то во второй группе (интубация трахеи) этот показатель достигала до 35,7%(P<0,05).Подобное соотношение в той или иной степени были характерными и в 4-м этапе . однако во время «пика» операции (3-й этап обследования) в обеих группах уровень кортизола в крови приближалась к исходному, что доказывал адекватности анестезии в обеих группах. кроме этого применение ЛМ в замен интубации трахеи наряду с наименьшей реакцией стрессого ответа организма , позволяет уменьшить появление нежелательных симптомов в послеоперационном периоде в верхних дыхательных путях
Coulomb drag between ballistic one-dimensional electron systems
The presence of pronounced electronic correlations in one-dimensional systems
strongly enhances Coulomb coupling and is expected to result in distinctive
features in the Coulomb drag between them that are absent in the drag between
two-dimensional systems. We review recent Fermi and Luttinger liquid theories
of Coulomb drag between ballistic one-dimensional electron systems, and give a
brief summary of the experimental work reported so far on one-dimensional drag.
Both the Fermi liquid (FL) and the Luttinger liquid (LL) theory predict a
maximum of the drag resistance R_D when the one-dimensional subbands of the two
quantum wires are aligned and the Fermi wave vector k_F is small, and also an
exponential decay of R_D with increasing inter-wire separation, both features
confirmed by experimental observations. A crucial difference between the two
theoretical models emerges in the temperature dependence of the drag effect.
Whereas the FL theory predicts a linear temperature dependence, the LL theory
promises a rich and varied dependence on temperature depending on the relative
magnitudes of the energy and length scales of the systems. At higher
temperatures, the drag should show a power-law dependence on temperature, R_D
\~ T^x, experimentally confirmed in a narrow temperature range, where x is
determined by the Luttinger liquid parameters. The spin degree of freedom plays
an important role in the LL theory in predicting the features of the drag
effect and is crucial for the interpretation of experimental results.Comment: 25 pages, 14 figures, to appear in Semiconductor Science and
Technolog
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