Synthesis of Nanocomposite Adsorbent on the Base of Polypropylene Fabric with Copper Ferrocyanide Grains

Composite adsorbents based on polypropylene fibers with chemically bound nanopartices of copper fer-rocyanide were synthesized by two-stage experiment: radiation-induced graft polymerization of acrylic acid onto non-woven polypropylene fabric followed by in-situ formation of copper ferrocyanize nanoparticles and their stabilization on the fabric surface within the grafted layer. Scanning electron microscope investiga-tions revealed a homogeneous compact layer of copper ferrocynide nanosized aggregates (65-70 nm). The synthesized composite material was stable in the base solutions (pH 10.5) and exhibited high efficiency for cesium adsorption. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3545

Synthesis of Polypropylene Fiber / Hydrated Iron Oxide Nanocomposite Adsorbent

Composite adsorbent based on the polypropylene fibers with chemically bound nanoparticles of hydrated iron (III) oxide were synthesized by two-stage experiment: radiation-induced graft polymerization of acrylic acid onto the surface of polypropylene fibers followed by the in-situ formation of hydrated iron oxide nanoparticles and their stabilization on the fibers‟ surface within the grafted layer. SEM and XRD investigations revealed a compact homogeneous layer of amorphous nanoaggregates (70-100 nm) formed by iron hydroxide on the fibers‟ surface. The synthesized nanocomposite fibers were stable in the aggressive medium for a long time and exhibited good adsorption properties for uranyl ions. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3558

Confirming anthropogenic influences on the major organic and inorganic constituents of rainwater in an urban area

Recently, rainwater composition affected by atmospheric pollutants has been the topic of intense study in East Asia because of its adverse environmental and human health effects. In the present study, the chemical composition and organic compounds of rainwater were investigated from June to December 2012 at Gwangju in Korea. The aim of this study is to determine the seasonal variation of rainwater chemical composition and to identify possible sources of inorganic and organic compounds. The volume-weighted mean of pH ranged from 3.83 to 8.90 with an average of 5.78. Of rainwater samples, 50 % had pH values below 5.6. The volume-weighted mean concentration (VWMC) of major ions followed the order Cl- > SO4 2- > NH4+ > Na+ > NO3- > Ca2+ > Mg2+ > K+. The VWMC of trace metals decreased in the order Zn > Al > Fe > Mn > Pb > Cu > Ni > Cd > Cr. The VWMCs of major ions and trace metals were higher in winter than in summer. The high enrichment factors indicate that Zn, Pb, Cu, and Cd originated predominantly from anthropogenic sources. Factor analysis (principal component analysis) indicates the influence of anthropogenic pollutants, sea salt, and crustal materials on the chemical compositions of rainwater. Benzoic acids, 1H-isoindole-1,3(2H)-dione, phthalic anhydride, benzene, acetic acids, 1,2-benzenedicarboxylic acids, benzonitrile, acetaldehyde, and acetamide were the most prominent pyrolysis fragments for rainwater organic compounds identified by pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). The results indicate that anthropogenic sources are the most important factors affecting the organic composition of rainwater in an urban area. © 2015 Author(s)open

A visibility-based lower bound for android unlock patterns

The Android pattern unlock is a widely adopted graphical password system that requires a user to draw a secret pattern connecting points arranged in a grid. The theoretical security of pattern unlock can be defined by the number of possible patterns. However, only upper bounds of the number of patterns have been known except for 3��3 and 4��4 grids for which the exact number of patterns was found by brute-force enumeration. In this letter, we present the first lower bound by computing the minimum number of visible points from each point in various subgrids. ? 2017 The Institute of Electronics, Information and Communication Engineers.11Ysciescopu

Production of Sorption Active Polypropylene Fabrics with Sulfonic Acid Groups by Radiation-Induced Modification of Polymer Surface

Sorption active material carrying sulfonic acid groups was synthesized by radiation-induced graft polymerization of styrene monomer onto the surface of non-woven polypropylene fabric followed by sulfonation of grafted polystyrene chains. The effect of the main experimental parameters on styrene grafting degree (absorbed dose, monomer concentration, reaction time) was investigated. It was found that sulfonation degree of the grafted polystyrene chains with 5% chlorosulfonic acid at room temperature depends on the reaction time and reaches 80% for the samples with a medium value of styrene grafting degree. Sorption active polypropylene fabrics with sulfonic acid group densities of 3.5–5 meq/g were obtained.Радіаційно-індукована прищеплювальна полімеризація стиролу на неткану поліпропіленову тканину з подальшим сульфуванням прищеплених ланцюгів полістиролу була використана для синтезу сорбційно-активного матеріалу. Проведено дослідження впливу основних експериментальних параметрів (поглинена доза, концентрація мономера, час реакції) на ступінь прищеплювальної полімеризації стиролу. Встановлено, що ефективність сульфування прищеплених ланцюгів полістиролу при кімнатній температурі в 5% розчині хлорсульфонової кислоти залежить від часу реакції і для зразків з середніми ступенями прищеплення досягає 80%. Були синтезовані сорбційно-активні поліпропіленові тканини з щільністю кислотних груп 3,5–5 мг-екв/г.Радиационно-индуцированная прививочная полимеризация стирола на нетканной полипропиленовой материи с последующим сульфированием привитых цепей полистирола была использована для синтеза сорбционно-активного материала. Проведено исследование влияния основных экспериментальных параметров (поглощенная доза, концентрация мономера, время реакции) на степень прививочной полимеризации стирола. Установлено, что эффективность сульфирования привитых цепей полистирола при комнатной температуре в 5% растворе хлорсульфоновой кислоты зависит от времени реакции и для образцов со средними степенями прививки достигает 80%. Были синтезированы сорбционно-активные полипропиленовые ткани с плотностью кислотных групп 3,5–5 мг-экв/г

Modeling of Ultra Low Capacitance Transient Voltage Suppression Diode for High ESD Protection

To improve key properties such as ultra-low capacitance (ULC) and high-voltage (HV) breakdown, we have performed a simulation work about transient voltage suppression (TVS) diodes. ULC-TVS diode was designed to employ a double deep trench to cut off the various parasitic effects that may degrade the device performance. The electrostatic discharge (ESD) protection is the targeting for the best applications in high-frequency and high-speed ICs. In this work, the device could present excellent performance in terms of very responsive ESD properties, high breakdown voltage, low leakage current, and very low capacitance level. The double trenches are aligned to the top electrode contact to restrict field crowding effects by the strong electric field intensity. The performance would be sufficient for the robust ESD nature up to IEC61000-4-2 (30 kV) and compatible with strong surge protection IEC61000-4-5 (10A). Their electrical properties have been evaluated for structure from simulation and the results are obtained at the device parameters. Several process of device design related effects on the electrical capability and can be optimized. Keywords: ULC-TVS diode, simulation (TCAD), characteristics, capacitance, ESD protection

Experimental and numerical investigation on cross flow in the PMR200 core

Papers presented to the 11th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 20-23 July 2015.The Prismatic Modular Reactor (PMR) is one of the major Very High Temperature Reactor (VHTR) concepts, which consists of hexagonal prismatic fuel blocks and reflector blocks made of nuclear grade graphite. However, the shape of graphite blocks could be easily changed by neutron damage during the reactor operation and the shape change can make the gaps between the blocks inducing bypass flow. Two types of gap shape should be considered. The vertical gap and horizontal gap are called bypass gap and cross gap, respectively. The cross gap complicates flow field in reactor core by connecting coolant channel and bypass gap and it could lead to loss of effective coolant flow in fuel blocks. In this paper, cross flow experimental facility was constructed to investigate the cross flow phenomena in the core of the VHTR and the experiment was carried out under varying flow rates and gap sizes. The results of the experiments were compared with CFD (Computational Fluid Dynamics) analysis results. In order to apply the CFD code to the cross flow phenomena, the prediction capability of the CFD code was verified. Good agreement between experimental results and CFD predictions was observed and the characteristics of the cross flow was discussed in detail.This work was supported by a Basic Atomic Energy Research Institute (BAERI) grant funded by the Korean government Ministry of Education and Science Technology (MEST) (NRF-2010-0018759)am201

TeV scale partial mirage unification and neutralino dark matter

We study the TeV scale partial mirage unification scenario, where the gluino and wino masses are degenerate around a TeV scale, but the bino mass is not degenerate. This scenario has phenomenologically interesting aspects. First, because of the degeneracy between the gluino and wino masses, this scenario does not have the little hierarchy problem, that is, the higgisino mass is around 150 GeV. The lightest superparticle is a mixture of the bino and higgsino, and can lead to a right amount of thermal relic density as a dark matter candidate

On Traversable Lorentzian Wormholes in the Vacuum Low Energy Effective String Theory in Einstein and Jordan Frames

Three new classes (II-IV) of solutions of the vacuum low energy effective string theory in four dimensions are derived. Wormhole solutions are investigated in those solutions including the class I case both in the Einstein and in the Jordan (string) frame. It turns out that, of the eight classes of solutions investigated (four in the Einstein frame and four in the corresponding string frame), massive Lorentzian traversable wormholes exist in five classes. Nontrivial massless limit exists only in class I Einstein frame solution while none at all exists in the string frame. An investigation of test scalar charge motion in the class I solution in the two frames is carried out by using the Plebanski-Sawicki theorem. A curious consequence is that the motion around the extremal zero (Keplerian) mass configuration leads, as a result of scalar-scalar interaction, to a new hypothetical "mass" that confines test scalar charges in bound orbits, but does not interact with neutral test particles.Comment: 18 page