Modeling of Novel Plasma-Optical Systems

This is the review of the current status an ongoing theoretical, simulations and some experimental researches of the novel plasma dynamical devices based on the axial-symmetric cylindrical electrostatic plasma lens (PL) configuration and the fundamental plasma-optical principles of magnetic electron isolation and equipotentialization magnetic field lines. The crossed electric and magnetic fields plasma lens configuration provides us with the attractive and suitable method for establishing stable plasma discharge at low-pressure. Using plasma lens configuration in this way some novel cost-effective, low-maintenance, high-reliability plasma devices using permanent magnets were developed. In part, it was proposed and created device for ion treatment and deposition of exotic coatings, device for filtering dense plasma flow from micro-droplets, electrostatic plasma lens for focusing and manipulating wide aperture, high-current, low-energy, heavy metal ion plasma flow, and the effective lens was first proposed for manipulating high-current beams of negatively charged particles (negative ions and electrons). Here we mainly describe models and results of theoretical consideration and simulation of the novel generation cylindrical plasma devices

Linking active margin dynamics to overriding plate deformation: Synthesizing geophysical images with geological data from the Norfolk Basin

The Tonga-Kermadec subduction system in the southwest Pacific preserves a series of crustal elements and sediments which have recorded subduction initiation, rift, and back-arc basin formation. The Norfolk Basin is the farthest landward of all back-arc basins formed in the Tonga-Kermadec region and may preserve the earliest record of subduction initiation regionally. For the Norfolk Basin, we use a set of multibeam bathymetry, magnetic, and seismic reflection and refraction data to constrain basin structure and the mode and timing of formation. A structural interpretation reveals a two-stage tectonic evolution: (1) a convergent tectonic regime until 38–34 Ma, alternatively related to island arc collision or subduction initiation, and (2) lithospheric extension after 34 Ma. These observations may help to constrain mechanical models that predict rapid extension following convergence of the overriding plate during subduction initiation or arc reversals

Properties of Fibrous Scaffolds from Poly(3-Hydroxybutyrate), Polylactide, Polyglycolide and Poly(Lactide-Glycolide) with Various Methods of Electrostatic Forming

Методом электростатического формования с использованием одного или двух подающих капилляров на один собирающий коллектор получены нетканые изделия из растворов полимеров поли-3-гидроксибутирата, полилактида и полигликолида и сополимера поли(лактид-гликолида) и исследованы их характеристики. Показано, что при использовании двух подающих капилляров происходит пространственное распределение волокон, имеющих различную химическую структуру, по слоям нетканого изделия. Выявлено влияние состава используемых растворов полимеров на гидрофильно-гидрофобные свойства нетканых изделий вне зависимости от способа электростатического формованияFibrous scaffolds from polymer solutions of poly-3-hydroxybutyrate, polylactide and polyglycolide, and copolymer of poly(lactide-glycolide) were obtained using electrostatic shaping with one or two feeding capillaries on one collecting manifold and their characteristics were studied. The spatial distribution of fibers having different chemical structure in layers of fibrous scaffolds occurred when two feeding capillaries were used. The composition of polymer solutions influenced on the hydrophilic-hydrophobic properties of fibrous scaffolds, regardless of the method of electrostatic moldin

Rheology of Polyhydroxyalkanoate Solutions

Исследована реология растворов ПГА различного химического строения в хлороформе и дихлорметане. Показано, что динамическая вязкость растворов зависит от типа растворителя и типа ПГА, при этом исследуемые растворы полимеров при увеличении температуры ведут себя как ньютоновские жидкости. Повышение концентрации полимеров в растворе способствует увеличению динамической вязкости независимо от растворителя. Растворы ПГА по убыванию величины динамической вязкости можно расположить в следующем порядке: П(3ГБ) – П(3ГБ-3ГВ) – П(3ГБ-3ГГ) – П(3ГБ-4ГБ). При этом величина динамической вязкости растворов при одинаковых концентрации и температуре у растворов на основе хлороформа в 3–3,5 раза выше, чем у растворов на основе дихлорметана. Полученные значения динамической вязкости для разных типов полигидроксиалканоатов и двух основных типов растворителей свидетельствуют о зависимости исследуемого реологического параметра как от химического состава полимера, так и от характеристик (состав, температура, концентрация) используемого растворителяThe rheology of solutions of polyhydroxyalkanoates in chloroform and dichloromethane was studied. The dynamic viscosity of solutions depended on type of solvent and PHA. The polymer solutions with increase of temperature behave as Newtonian fluids. Dynamic viscosity was increasing with the concentration of polymer in solution, regardless of the solvent. Solutions of PHAs in descending order of magnitude of dynamic viscosity can be positioned in the following order: P(3HB) – P(3HB-3HV) – P(3GB-3HH) – P(3HB-4HB). The magnitude of the dynamic viscosity of solutions based on chloroform in 3-3,5 times higher than that of solutions based on dichloromethane at identical concentration and temperature. The obtained values of dynamic viscosity have demonstrated the dependence of rheological parameter on the chemical composition of the polymer, and the characteristics of solvent (composition, temperature, and concentration

The Emerging Field Trends Erosion-Free Electric Hall Thrusters Systems

The Hall-type accelerator with closed Hall current and open (that is unbounded by metal or dielectric) walls was proposed and considered both theoretically and experimentally. The novelty of this accelerator is the use of a virtual parallel surface of the anode and the cathode due to the principle of equipotentialization of magnetic field lines, which allows to avoid sputtering of the cathode surface and preserve the dynamics of accelerated ions. The formation of the actual traction beam should be due to the acceleration of ions with the accumulated positive bulk charge. A two-dimensional hybrid model in cylindrical coordinates is created in the framework of which the possibility of creation a positive space charge at the system axes is shown. It is shown that the ions flow from the hump of electrical potential can lead to the creation of a powerful ion flow, which moves along the symmetry axis in both sides from the center

Blood Pressure in Relation to Concentrations of PCB Congeners and Chlorinated Pesticides

BackgroundResidents of Anniston, Alabama, live near a Monsanto plant that manufactured polychlorinated biphenyls (PCBs) from 1929 to 1971 and are relatively heavily exposed.ObjectivesThe goal of this study was to determine the relationship, if any, between blood pressure and levels of total serum PCBs, several PCB groups with common actions or structure, 35 individual PCB congeners, and nine chlorinated pesticides.MethodsLinear regression analysis was used to determine the relationships between blood pressure and serum levels of the various contaminants after adjustment for age, body mass index, sex, race, smoking, and exercise in 394 Anniston residents who were not taking antihypertensive medication.ResultsOther than age, total serum PCB concentration was the strongest determinant of blood pressure of the covariates studied. We found the strongest associations for those PCB congeners that had multiple ortho chlorines. We found the associations over the full range of blood pressure as well as in those subjects whose blood pressure was in the normal range. The chlorinated pesticides showed no consistent relationship to blood pressure.ConclusionsIn this cross-sectional study, serum concentrations of PCBs, especially those congeners with multiple ortho chlorines, were strongly associated with both systolic and diastolic blood pressure

Lower Serum Testosterone Associated with Elevated Polychlorinated Biphenyl Concentrations in Native American Men

Background: Polychlorinated biphenyls (PCBs) and chlorinated pesticides are endocrine disruptors, altering both thyroid and estrogen hormonal systems. Less is known of action on androgenic systems. Objective: We studied the relationship between serum concentrations of testosterone in relation to levels of PCBs and three chlorinated pesticides in an adult Native American (Mohawk) population. Methods: We collected fasting serum samples from 703 adult Mohawks (257 men and 436 women) and analyzed samples for 101 PCB congeners, hexachlorobenzene (HCB), dichlorodiphenyldichloroethylene (DDE), and mirex, as well as testosterone, cholesterol, and triglycerides. The associations between testosterone and tertiles of serum organochlorine levels (both wet weight and lipid adjusted) were assessed using a logistic regression model while controlling for age, body mass index (BMI), and other analytes, with the lowest tertile being considered the referent. Males and females were considered separately. Results: Testosterone concentrations in males were inversely correlated with total PCB concentration, whether using wet-weight or lipid-adjusted values. The odds ratio (OR) of having a testosterone concentration above the median was 0.17 [95% confidence interval (CI), 0.05–0.69] for total wet-weight PCBs (highest vs. lowest tertile) after adjustment for age, BMI, total serum lipids, and three pesticides. The OR for lipid-adjusted total PCB concentration was 0.23 (95% CI, 0.06–0.78) after adjustment for other analytes. Testosterone levels were significantly and inversely related to concentrations of PCBs 74, 99, 153, and 206, but not PCBs 52, 105, 118, 138, 170, 180, 201, or 203. Testosterone concentrations in females are much lower than in males, and not significantly related to serum PCBs. HCB, DDE, and mirex were not associated with testosterone concentration in either men or women. Conclusions: Elevation in serum PCB levels is associated with a lower concentration of serum testosterone in Native American men

Composition and Formation of Gabbro-Peridotite Hosted Seafloor Massive Sulfide Deposits from the Ashadze-1 Hydrothermal Field, Mid-Atlantic Ridge

This paper presents mineralogical and geochemical data on seafloor massive sulfides (SMS) from the Ashadze-1 hydrothermal field at the Mid-Atlantic Ridge (MAR). The Ashadze-1 deposit is associated with the uplifted lower crust and upper mantle (oceanic core complex, OCC) of the MAR segment characterized by asymmetric mode of accretion. The OCC is represented by deep-seated gabbro-peridotite rocks exhumed on the rift valley slope along the detachment fault, during seafloor spreading. Hydrothermal processes in OCC environments result in different deposit composition and morphology compared to basalt-hosted systems. Abundant chimneys and enrichment in particular metals, including copper, zinc, gold, cobalt and tin are typical for this type of SMS deposit. The Ashadze-1 deposit is considered an example of a hydrothermal system in the initial stage of evolution marked by the young age of the sulfides (<7.2 kyr). The mineralogy of Ashadze-1 reflects primary ore-forming processes unaffected by post formation alteration. We propose a model for the primary ore-forming hydrothermal process in an ultramafic-hosted environment on the modern seafloor