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2019

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Articles 31 - 60 of 421

Full-Text Articles in Physical Sciences and Mathematics

Towards Completely Automated Glycan Synthesis, Matteo Panza Nov 2019

Towards Completely Automated Glycan Synthesis, Matteo Panza

Dissertations

Carbohydrates are ubiquitous both in nature as biologically active compounds and in medicine as pharmaceuticals. Although there has been continued interest in the synthesis of carbohydrates, chemical methods require specialized knowledge and hence remain cumbersome. The need for development of rapid, efficient and operationally simple procedures has come to the fore. This dissertation focuses on the development of a fully automated platform that will enable both experts and non-specialists to perform the synthesis of glycans. Existing automated methods for the synthesis of oligosaccharides are highly sophisticated, operationally complex, and require significant user know-how. By contrast, high performance liquid chromatography (HPLC) …

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The Application Of Gray-Scale Level-Set Method In Segmentation Of Concrete Deck Delamination Using Infrared Images, Chongsheng Cheng, Zhigang Shen Nov 2019

The Application Of Gray-Scale Level-Set Method In Segmentation Of Concrete Deck Delamination Using Infrared Images, Chongsheng Cheng, Zhigang Shen

Department of Construction Engineering and Management: Faculty Publications

Conventional nondestructive delamination detection of concrete pavements through thermography is often based on temperature contrasts between delaminated and sound areas. Non-uniform backgrounds caused by the environmental conditions are often challenging for contrast-based methods to robustly differentiate the delaminated areas from the sound areas. Instead of focusing on the temperature contrast, this study proposes a temperature gradient-based level set method (LSM) to detect boundaries for delamination segmentations. A modified edge indicator function is developed to represent the normalized temperature gradient of a thermal image. The experimental study was conducted to evaluate its applicability and stability for boundary detection in terms of …

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First-Principles Simulations Of Materials Under Extreme Conditions, Kien Nguyen Cong Nov 2019

First-Principles Simulations Of Materials Under Extreme Conditions, Kien Nguyen Cong

USF Tampa Graduate Theses and Dissertations

The investigation of materials at extreme conditions of high pressure and temperature (high-PT), has been one of the greatest scientific endeavors in condensed mater physics, chemistry, astronomy, planetary, and material sciences. Being subjected to high-PT conditions, materials exhibit dramatic changes in both atomic and electronic structure resulting in an emergence of exceptionally interesting phenomena including structural and electronic phase transitions, chemical reactions, and formation of novel compounds with never-previously observed physical and chemical properties. Although new exciting experimental developments in static and dynamic compression combined with new diagnostics/characterization methods allow to uncover new processes and phenomena at high P-T conditions, …

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Why The Crackling Deformations Of Single Crystals, Metallic Glasses, Rock, Granular Materials, And The Earth’S Crust Are So Surprisingly Similar, Karin A. Dahmen, Jonathan T. Uhl, Wendelin J. Wright Nov 2019

Why The Crackling Deformations Of Single Crystals, Metallic Glasses, Rock, Granular Materials, And The Earth’S Crust Are So Surprisingly Similar, Karin A. Dahmen, Jonathan T. Uhl, Wendelin J. Wright

Faculty Journal Articles

Recent experiments show that the deformation properties of a wide range of solid materials are surprisingly similar. When slowly pushed, they deform via intermittent slips, similar to earthquakes. The statistics of these slips agree across vastly different structures and scales. A simple analytical model explains why this is the case. The model also predicts which statistical quantities are independent of the microscopic details (i.e., they are "universal"), and which ones are not. The model provides physical intuition for the deformation mechanism and new ways to organize experimental data. It also shows how to transfer results from one scale to another. …

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Fabrication And Characterization Of Electrical Energy Storage And Harvesting Energy Devices Using Gel Electrolytes, Belqasem Aljafari Nov 2019

Fabrication And Characterization Of Electrical Energy Storage And Harvesting Energy Devices Using Gel Electrolytes, Belqasem Aljafari

USF Tampa Graduate Theses and Dissertations

Redox-active materials in the bulk of gel electrolytes are unquestionably holding the primary roles in developing energy harvesting and storage technology. Both technologies are necessary in order to cope with the current challenges of the environmental crises of global warming and finite non-renewable sources while the demand for energy modern societies have been speedily increased. One of the most challenges of making a hybrid device of energy conversion and storage is the cost of the fabrication process. Therefore, gel electrolyte-based materials with redox-active properties can potentially be a promising solution to improve the performance of electrochemical and photoelectrochemical devices for …

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From Critical Behavior To Catastrophic Runaways: Comparing Sheared Granular Materials With Bulk Metallic Glasses, Alan A. Long, Dmitry Denisov, Peter Schall, Todd C. Hufnagel, Xiaojun Gu, Wendelin J. Wright, Karin A. Dahmen Nov 2019

From Critical Behavior To Catastrophic Runaways: Comparing Sheared Granular Materials With Bulk Metallic Glasses, Alan A. Long, Dmitry Denisov, Peter Schall, Todd C. Hufnagel, Xiaojun Gu, Wendelin J. Wright, Karin A. Dahmen

Faculty Journal Articles

The flow of granular materials and metallic glasses is governed by strongly correlated, avalanche-like deformation. Recent comparisons focused on the scaling regimes of the small avalanches, where strong similarities were found in the two systems. Here, we investigate the regime of large avalanches by computing the temporal profile or “shape” of each one, i.e., the time derivative of the stress-time series during each avalanche. We then compare the experimental statistics and dynamics of these shapes in granular media and bulk metallic glasses. We complement the experiments with a mean-field model that predicts a critical size beyond which avalanches turn into …

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Thermo-Oxidative Degradation Of Hdpe Geomembranes: Effect Of Phenolic Antioxidant And Hindered Amine Light Stabilizer Concentrations, Yasin Kocak Oct 2019

Thermo-Oxidative Degradation Of Hdpe Geomembranes: Effect Of Phenolic Antioxidant And Hindered Amine Light Stabilizer Concentrations, Yasin Kocak

USF Tampa Graduate Theses and Dissertations

High density polyethylene (HDPE) geomembrane is most common geomembrane which is mainly used for civil engineering applications. However, HDPE geomembrane loses its properties under oxidative degradation progress. This study aims to assess geomembranes which have different percentage of phenolic antioxidant and hindered amine light stabilizer (HALS) with under the six months of the thermal-oxidative degradation. The interactions between phenolic antioxidant, HALS and carbon black can affect the mechanical, physical and chemical properties. To monitor these properties, Differential Scanning Calorimetry (DSC), Fourier-transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy coupled with Energy Dispersive X-ray spectroscopy (SEM/EDX), Melt Index tests, …

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Progress In Solar Photocatalytic Hydrogen Production, Zhi Wu, Lan Sun, Chang-Jian Lin Oct 2019

Progress In Solar Photocatalytic Hydrogen Production, Zhi Wu, Lan Sun, Chang-Jian Lin

Journal of Electrochemistry

With the rapid development of human society and dramatically consumption of traditional energy, energy shortage and environmental pollution have become an important factor restricting the sustainable development of human society. At present, the development of clean and environmentally friendly renewable energy system has drawn much attention and becomes an important priority stratagem in the world. In many green and sustainable new energy projects, semiconductor-based photocatalytic hydrogen production technology which utilizes the available clean and renewable solar energy to prepare clean hydrogen energy is excepted to solve the crisis of energy shortage and environmental pollution, has become one of the most …

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Special Issue: Electrocatalysis And Fuel Cells, Shuangyin Wang Oct 2019

Special Issue: Electrocatalysis And Fuel Cells, Shuangyin Wang

Journal of Electrochemistry

Around electrocatalysis and fuel cell, this album contains 7 research papers and reviews written by these teams with rich accumulation and influence in related research fields. This album partly reflects the research progress in the design, synthesis and performance of electrocatalysts in China. With the publication of this special issue, it is hoped that readers will have a better understanding of the current research situation in this field in China. To promote the further development of electrocatalytic chemistry and new fuel cell research in China.

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Nickel Selenide Derived From [Ni(En)3](Seo3) Complex For Efficient Electrocatalytic Overall Water Splitting, Dan-Dan Chen, Xue-Qing Gao, Hong-Fei Liu, Wei Zhang, Rui Cao Oct 2019

Nickel Selenide Derived From [Ni(En)3](Seo3) Complex For Efficient Electrocatalytic Overall Water Splitting, Dan-Dan Chen, Xue-Qing Gao, Hong-Fei Liu, Wei Zhang, Rui Cao

Journal of Electrochemistry

Electrocatalytic water splitting is considered as a promising technology for renewable energy. The development of efficient, stable, cost-effective, and bifunctional catalysts for both water reduction and oxidation has continued to face significant challenges. Herein, we report a robust and highly active nickel selenide (NiSe) spheres grown on carbon cloth (CC) by electrodeposition from a nickel selenite complex which is a single source containing both Ni and Se. A combination of two chemicals containing, separately, Ni and Se is used in traditional preparations of metal selenides, causing possible problems in the uniformity of the products. The as-prepared NiSe-EA/CC electrode exhibited electrocatalytic …

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Three-Dimensional Porous Vn Octahedron Catalyst With High Electrocatalytic Efficiency Toward Hydrogen Evolution Reaction, Can Yin, Wei-Wei Fu, Ling Fang, Shi-Li You, Hui-Juan Zhang, Yu Wang Oct 2019

Three-Dimensional Porous Vn Octahedron Catalyst With High Electrocatalytic Efficiency Toward Hydrogen Evolution Reaction, Can Yin, Wei-Wei Fu, Ling Fang, Shi-Li You, Hui-Juan Zhang, Yu Wang

Journal of Electrochemistry

With the rapid development of China’s economy, the demand for energy is increasing, and environmental problems are becoming more and more serious. The development and utilization of highly-clean new energy fuel can effectively alleviate the energy crisis and environmental pollution. Nowadays, exploring high-efficiency, environment-friendly and low-cost catalysts remains the focus of research in the hydrogen evolution reaction (HER). In this research, firstly, we proposed a three-dimensional porous vanadium nitride (VN) with octahedral structure, which was prepared by a calcination treatment method. The VN catalyst showed a good electrocatalytic activity toward HER, involving a small overpotential of 94.0 mV at -10 …

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Influences Of Morphology And Nitrogen Doping On The Electrocatalytic Characteristics For Oxygen Reduction Reaction Of Nio/Rgo, Dong Liang, Heng-Yi Fang, Shuo Yao, Jie-Mei Yu, Zhao-Liang Zhang, Zhan-Kun Jiang, Xue-Ping Gao, Tai-Zhong Huang Oct 2019

Influences Of Morphology And Nitrogen Doping On The Electrocatalytic Characteristics For Oxygen Reduction Reaction Of Nio/Rgo, Dong Liang, Heng-Yi Fang, Shuo Yao, Jie-Mei Yu, Zhao-Liang Zhang, Zhan-Kun Jiang, Xue-Ping Gao, Tai-Zhong Huang

Journal of Electrochemistry

In this research, the reduced graphene oxide (rGO) supported sheet-like NiO (NiO/rGO) and spherical-like NiO (NiO/N-rGO) catalysts for oxygen reduction reaction (ORR) were prepared. The structures, morphologies and chemical states of the two catalysts were characterized by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrochemical catalytic performance of the two catalysts for ORR were investigated by cyclic voltammetry (CV), Tafel, linear sweeping voltammetry (LSV), rotating disc electrode (RDE) and rotating ring disc electrode (RRDE) tests. Electrochemical results showed that the current density and onset potential (about 0.89 V) …

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Preparation Of Nanostructural Mno-Porous Graphene Hybrid Material By Thermally-Driven Etching Of Mno For Lithium-Air Batteries, Juan Yang, Jun-Wei Lang, Peng Zhang, Bao Liu Oct 2019

Preparation Of Nanostructural Mno-Porous Graphene Hybrid Material By Thermally-Driven Etching Of Mno For Lithium-Air Batteries, Juan Yang, Jun-Wei Lang, Peng Zhang, Bao Liu

Journal of Electrochemistry

In this paper, improving the surface morphology of graphene(GNSs) as designed concept. we describe a MnO/porous-graphene(MnO-PGNSs) was synthesized by a simple site-localized Mn2+ on GO (Mn-GO) by charge adsorption and then driving by high-temperature calcination, growing MnO nanoparticles and etching GNSs achieved on step. And Then focus on the key factors of influenced the etch hole formation are analyzed, founded the dispersion of Mn-GO; layer number of GO and calcination temperature also affected the formation of holes. In addition, the MnO-PGNSs as lithium-air battery cathode exhibits high reversible capacity compared with GNSs and PGNs and it is able to …

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Investigations In Electrochemical Thermodynamic And Kinetic Properties Of As-Cast And As-Quenched Cemg10Ni2 Hydrogen Storage Alloys, Feng Hu, Li-Rong Luo, Yong-Zhi Li, Ting-Ting Zhai, Xin Zhao, Yang-Huan Zhang Oct 2019

Investigations In Electrochemical Thermodynamic And Kinetic Properties Of As-Cast And As-Quenched Cemg10Ni2 Hydrogen Storage Alloys, Feng Hu, Li-Rong Luo, Yong-Zhi Li, Ting-Ting Zhai, Xin Zhao, Yang-Huan Zhang

Journal of Electrochemistry

In order to improve the electrochemical hydrogen storage properties of CeMg10Ni2 alloy, the rapid quenching technology was used to prepare CeMg10Ni2 alloys with nano-crystalline and amorphous structure. The microstructures of as-cast and as-spinning sample were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The electrochemical hydrogen storage properties were investigated by an automatic galvanostatic charging/discharging, high rate discharging (HRD), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. The results revealed that the as-cast alloy was composed of multiphase structures. The as-quenched alloys were made up of nano-crystalline and/or amorphous structures, and the …

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A Facile Route To Synthesize Pt-Wo3 Nanosheets With Enhanced Electrochemical Performance For Her, Peng-Jie Jiang, Yi Lv, Chang-Miao Chen, Hong-Cheng He, Yong Cai, Ming Zhang Oct 2019

A Facile Route To Synthesize Pt-Wo3 Nanosheets With Enhanced Electrochemical Performance For Her, Peng-Jie Jiang, Yi Lv, Chang-Miao Chen, Hong-Cheng He, Yong Cai, Ming Zhang

Journal of Electrochemistry

Platinum-tungsten trioxide (Pt-WO3) nanosheets were synthesized on nickel foams (NFs) directly. As great conductive networks, NFs substrates could greatly improve the electrode performance of WO3. The modified platinum nanoparticles not only enhanced the electron transformation of catalysts, but also increased the active sites for hydrogen evolution reaction (HER). Pt-WO3/NF revealed a better catalytic activity than WO3/NFs with a smaller Tafel slope (80 mV·dec-1) and a lower overpotential of 72 mV at the current density of 10 mA·cm-2. In addition, Pt-WO3/NF showed great durability and stability during …

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Pd Nanoparticles Supported On The Etched Ni Foams As High-Performance Electrocatalysts For Direct Ethanol Fuel Cells, Chi Zhang, Cheng-Fei Li, Gao-Ren Li Oct 2019

Pd Nanoparticles Supported On The Etched Ni Foams As High-Performance Electrocatalysts For Direct Ethanol Fuel Cells, Chi Zhang, Cheng-Fei Li, Gao-Ren Li

Journal of Electrochemistry

The development of non-Pt anode electrocatalysts with high activity and long-term durability at low cost for fuel cells still remains enormous challenge. Here we report the Pd nanoparticles supported on Ni foams etched by the mixed acids (HNO3+H2SO4+H3PO4+CH3COOH) (Pd/ME-NF) that are designed and fabricated as high-performance electrocatalysts for ethanol oxidation in alkaline media. Because of the advantages of large open space, fast electrolyte penetration/diffusion and rapid electron transfer process, the Pd/ME-NF catalysts exhibited significantly improved electrocatalytic activity and durability compared with the commercial Pd/C catalysts.

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Magnetocaloric Effect Near Room Temperature In Quintenary And Sextenary Heusler Alloys, Benjamin D. White, R. I. Barabash, O. M. Barabash, I. Jeon, M. B. Maple Oct 2019

Magnetocaloric Effect Near Room Temperature In Quintenary And Sextenary Heusler Alloys, Benjamin D. White, R. I. Barabash, O. M. Barabash, I. Jeon, M. B. Maple

All Faculty Scholarship for the College of the Sciences

An inverse magnetocaloric effect is studied in Ni2Mn1+xX1-x-type Heusler alloys. Principally known for their shape-memory properties, these alloys also exhibit significant entropy and temperature changes (ΔS and ΔTAd, respectively) under adiabatic conditions when a modest magnetic field is applied. We investigated the impact on magnetocaloric properties of introducing substantial chemical disorder on the X-site (X = Si, Ga, In), of replacing Ni with nonmagnetic Ag, and of replacing a small amount of Mn with Gd. While a reduction in ΔS is observed in the first two cases, we observe a significant enhancement …

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Novel Avenues Toward Controlling The Photophysical Properties Of Ultra-Small Silicon Quantum Dots, Mohammed Abdelhameed Oct 2019

Novel Avenues Toward Controlling The Photophysical Properties Of Ultra-Small Silicon Quantum Dots, Mohammed Abdelhameed

Electronic Thesis and Dissertation Repository

Quantum dots (QDs) have attracted an increasing attention in the last decade over many conventional organic dyes. This is due to their unique optical properties including broad absorption spectra, high photostability, and size-tunable photoluminescence (PL). However, some toxicity concerns associated with traditional quantum dots have hindered their wide applicability. Interestingly, silicon quantum dots (SQDs) have been shown to be more advantageous than most of QDs thanks to their excellent biocompatibility and biodegradability, low cytotoxicity, and versatile surface functionalization capability. Thus, SQDs are promising candidates for various biological and biomedical applications such as bioimaging, biosensing, and photodynamic therapy. Unfortunately, only a …

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Competing Magnetic Phases And Itinerant Magnetic Frustration In Srco2 As2, Bing Li, Benjamin G. Ueland, W. T. Jayasekara, D. L. Abernathy, N. S. Sangeetha, David C. Johnston, Qing-Ping Ding, Yuji Furukawa, Peter P. Orth, Andreas Kreyssig, Alan I. Goldman, Robert J. Mcqueeney Oct 2019

Competing Magnetic Phases And Itinerant Magnetic Frustration In Srco2 As2, Bing Li, Benjamin G. Ueland, W. T. Jayasekara, D. L. Abernathy, N. S. Sangeetha, David C. Johnston, Qing-Ping Ding, Yuji Furukawa, Peter P. Orth, Andreas Kreyssig, Alan I. Goldman, Robert J. Mcqueeney

A. I. Goldman

Whereas magnetic frustration is typically associated with local-moment magnets in special geometric arrangements, here we show that SrCo2As2 is a candidate for frustrated itinerant magnetism. Using inelastic neutron scattering (INS), we find that antiferromagnetic (AF) spin fluctuations develop in the square Co layers of SrCo2As2 below T approximate to 100 K centered at the stripe-type AF propagation vector of (1/2, 1/2), and that their development is concomitant with a suppression of the uniform magnetic susceptibility determined via magnetization measurements. We interpret this switch in spectral weight as signaling a temperature-induced crossover from an instability toward ferromagnetism ordering to an instability …

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Computationally Aided Design Of A High-Performance Organic Semiconductor: The Development Of A Universal Crystal Engineering Core, Anthony J. Petty Ii, Qianxiang Ai, Jeni C. Sorli, Hamna F. Haneef, Geoffrey E. Purdum, Alex M. Boehm, Devin B. Granger, Kaichen Gu, Carla Patricia Lacerda Rubinger, Sean R. Parkin, Kenneth R. Graham, Oana D. Jurchescu, Yueh-Lin Loo, Chad Risko, John E. Anthony Oct 2019

Computationally Aided Design Of A High-Performance Organic Semiconductor: The Development Of A Universal Crystal Engineering Core, Anthony J. Petty Ii, Qianxiang Ai, Jeni C. Sorli, Hamna F. Haneef, Geoffrey E. Purdum, Alex M. Boehm, Devin B. Granger, Kaichen Gu, Carla Patricia Lacerda Rubinger, Sean R. Parkin, Kenneth R. Graham, Oana D. Jurchescu, Yueh-Lin Loo, Chad Risko, John E. Anthony

Chemistry Faculty Publications

Herein, we describe the design and synthesis of a suite of molecules based on a benzodithiophene “universal crystal engineering core”. After computationally screening derivatives, a trialkylsilylethyne-based crystal engineering strategy was employed to tailor the crystal packing for use as the active material in an organic field-effect transistor. Electronic structure calculations were undertaken to reveal derivatives that exhibit exceptional potential for high-efficiency hole transport. The promising theoretical properties are reflected in the preliminary device results, with the computationally optimized material showing simple solution processing, enhanced stability, and a maximum hole mobility of 1.6 cm2 V−1 s−1.

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Nonlinear Characterizing Of A New Titanium Nitride On Aluminum Oxide Metalens, Michael A. Cumming Oct 2019

Nonlinear Characterizing Of A New Titanium Nitride On Aluminum Oxide Metalens, Michael A. Cumming

Theses and Dissertations

A sample metalens generated from Titanium Nitride deposited onto Aluminum Oxide was designed to focus at 10 microns with a beam centered at 800nm, and when analyzed with high intensity illumination was found to have a focal length of 9.650 ±.003µm at an intensity of 16.93[MW/cm2 ]. Analyzing this change by comparing it to a Fresnel Lens’ physics shows that for this lens, the effective nonlinear index of refraction is certainly greater than the nonlinear index of just Titanium Nitride itself, at −1.6239 × 10−15[m2/W] compared to the materials −1.3 × 10−15[m2 …

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Demonstration Of Visible And Near Infrared Raman Spectrometers And Improved Matched Filter Model For Analysis Of Combined Raman Signals, Alexander Matthew Atkinson Oct 2019

Demonstration Of Visible And Near Infrared Raman Spectrometers And Improved Matched Filter Model For Analysis Of Combined Raman Signals, Alexander Matthew Atkinson

Electrical & Computer Engineering Theses & Dissertations

Raman spectroscopy is a powerful analysis technique that has found applications in fields such as analytical chemistry, planetary sciences, and medical diagnostics. Recent studies have shown that analysis of Raman spectral profiles can be greatly assisted by use of computational models with achievements including high accuracy pure sample classification with imbalanced data sets and detection of ideal sample deviations for pharmaceutical quality control. The adoption of automated methods is a necessary step in streamlining the analysis process as Raman hardware becomes more advanced. Due to limits in the architectures of current machine learning based Raman classification models, transfer from pure …

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Creation Of Integrated System For Registration Radio Emissions From High-Energy Extensive Air Showers At An Altitude 3340 Meters Above Sea Level, M. Nassurlla, T. Kh. Sadykov, B. A. Iskakov, Y. M. Tautayev, K. Tastanova, M. B. Khabargeldina, A. I. Zhumabayev, A. D. Beisenova, A. Haungs, O. A. Novolodskaya, T. Idrisova, N. M. Salikhov Sep 2019

Creation Of Integrated System For Registration Radio Emissions From High-Energy Extensive Air Showers At An Altitude 3340 Meters Above Sea Level, M. Nassurlla, T. Kh. Sadykov, B. A. Iskakov, Y. M. Tautayev, K. Tastanova, M. B. Khabargeldina, A. I. Zhumabayev, A. D. Beisenova, A. Haungs, O. A. Novolodskaya, T. Idrisova, N. M. Salikhov

Eurasian Journal of Physics and Functional Materials

At the High mountain station of cosmic rays at an altitude of 3340 meters above sea level in 2018, work on modernization of registration of radio emission from extensive air showers was carried out. To date, 4 radio antennas have been installed in the direction of north, south, west, east at a distance of 30 meters from the registration center. Registration is carried out in the frequency range 30 - 80 MHz. As a result of the preliminary experiment, some event candidates were selected that demonstrate the presence of a noticeable radio signal pulse in the vicinity of the nearest …

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Safety Analysis For The Wwr-K Research Reactor Converted To Leu Fuel, S. N. Koltochnik, A. A. Shaimerdenov Sep 2019

Safety Analysis For The Wwr-K Research Reactor Converted To Leu Fuel, S. N. Koltochnik, A. A. Shaimerdenov

Eurasian Journal of Physics and Functional Materials

Recently in the WWR-K water-water research reactor the former HEU fuel, enriched to 36% in Uranium- 235, was changed to LEU one, enriched to 19.7%, with substantial change of the core configuration. In view of reactor conversion, a new Safety Analysis Report (SAR) was developed for the WWR-K reactor. Substantiation of reactor safe operation under both normal operation and emergency conditions was done under thermal-hydraulic approach. In the analysis developed prior to physical start up it was assumed that a main circulation pump (MCP) provides the coolant flow rate in the core equal to 350 m 3 /h (a certified …

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Neutron-Physical Parameters At The Outlet Of The Wwr-K Reactor Beam Tube, A. B. Bauyrzhan, S. N. Koltochnik, M. T. Aitkulov, D. S. Dyussambayev, A. A. Shaimerdenov, B. Mukhametuly, N. T. Burtebaev Sep 2019

Neutron-Physical Parameters At The Outlet Of The Wwr-K Reactor Beam Tube, A. B. Bauyrzhan, S. N. Koltochnik, M. T. Aitkulov, D. S. Dyussambayev, A. A. Shaimerdenov, B. Mukhametuly, N. T. Burtebaev

Eurasian Journal of Physics and Functional Materials

The paper is devoted to the neutron-physical parameters obtained via combined calculations and experimental measurements for the exit of the WWR-K reactor beam tube. The experimentally measured values of the thermal and fast neutron flux densities at the exit comprise 9.6 × 108 and 8.4 × 107 cm-2 s-1 , respectively. The dose rate of gamma-emission is 30 Sv/h. The obtained parameters will be used in designing of the collimation and screening systems of the installation for radiography and tomography to be created at the beam tube #1.

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Investigation Of Radio-Emission From Extensive Air Shower At High Mountain Cosmic Ray Station At An Altitude Of 3340 M Above Sea Level, M. Nassurlla, T. Kh. Sadykov, B. A. Iskakov, Y. M. Tautayev, K. Tastanova, M. B. Khabargeldina, A. I. Zhumabayev, A. D. Beisenova, A. Haungs, O. A. Novolodskaya, T. Idrisova, N. M. Salikhov Sep 2019

Investigation Of Radio-Emission From Extensive Air Shower At High Mountain Cosmic Ray Station At An Altitude Of 3340 M Above Sea Level, M. Nassurlla, T. Kh. Sadykov, B. A. Iskakov, Y. M. Tautayev, K. Tastanova, M. B. Khabargeldina, A. I. Zhumabayev, A. D. Beisenova, A. Haungs, O. A. Novolodskaya, T. Idrisova, N. M. Salikhov

Eurasian Journal of Physics and Functional Materials

The complex EAS installation of the Tien Shan mountain cosmic ray station which is situated at a height of 3340 m above sea level includes the scintillation and Cherenkov detectors of charged shower particles, an ionization calorimeter and a set of neutron detectors for registering the hadronic component of the shower, and a number of underground detectors of the penetrative EAS component. Now it is intended to expand this installation with a promising method for detecting the radio-emission generated by the particles of the developing shower. The facility for radio-emission detection consists of a three crossed dipole antennae, one being …

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Energy Transfer And Defect Formation Processes In Nano Silicon Under The Influence Of Epithermal Neutrons, A. Garibli Sep 2019

Energy Transfer And Defect Formation Processes In Nano Silicon Under The Influence Of Epithermal Neutrons, A. Garibli

Eurasian Journal of Physics and Functional Materials

The neutrons scattering and capture cross-section processes has been calculated for natural28Si ,29Si ,30Si isotopes which are main part of nanosilicon samples when irradiated for 20 hours by epithermal neutron flux. The values of energies has been determined which given to nanosilicon nuclei as a result of scattering processes in the energy intervals of investigated neutrons. The cross-sections of radiation capture process and the amount of31Si radioactive isotope which can be formed by by30Si isotope in the energy interval of epithermal neutrons, the parameters of energy supply and ionization processes …

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Change Of Electrophysical Properties Of The Si(111) And Si(100) Surface In The Process Of Ion Implantation And Next Annealing, A. S. Rysbaev, I. R. Bekpulatov, B. D. Igamov, Sh. X. Juraev Sep 2019

Change Of Electrophysical Properties Of The Si(111) And Si(100) Surface In The Process Of Ion Implantation And Next Annealing, A. S. Rysbaev, I. R. Bekpulatov, B. D. Igamov, Sh. X. Juraev

Eurasian Journal of Physics and Functional Materials

The change in the electrical properties of the Si(111) and Si(100) surfaces during ion implantation and subsequent annealing was studied. The possibilities of controlling of the electrophysical properties of the Si(111) and Si(100) surface layers by the implantation of ions of alkaline and alkaline-earth elements are analyzed. Some electrophysical properties of semiconductors containing p- and n-structures and the possibilities of their application in electronics are discussed.

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The Effect Of High-Temperature Annealing On The Phase Transformations Of The Perovskite Ytio3-X System, D. A. Mustakhieva, I. Z. Zhumataeva, A. L. Kozlovsky, K. K. Kadyrzhanov Sep 2019

The Effect Of High-Temperature Annealing On The Phase Transformations Of The Perovskite Ytio3-X System, D. A. Mustakhieva, I. Z. Zhumataeva, A. L. Kozlovsky, K. K. Kadyrzhanov

Eurasian Journal of Physics and Functional Materials

This paper presents the results of a study of the structural characteristics of perovskite systems based on YTiOx. These samples were subjected to heat treatment in the process of solid-phase synthesis. The change in physicochemical properties was investigated by scanning electron microscopy, X-ray structural and energy dispersive analysis. In the course of the work, it was found that the synthesized samples are a mixture of three phases characteristic of yttrium compounds with titanium. A quantitative change in the phases during the heat treatment indicates phase transformations and a change in the basic crystallographic characteristics. The results of these …

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Dynamical Approach For Synthesis Of Superheavy Elements: Fusion Mechanism And Nuclear Structure, Y. Aritomo, N. Liyana, B. Yanagi, H. Hachikubo Sep 2019

Dynamical Approach For Synthesis Of Superheavy Elements: Fusion Mechanism And Nuclear Structure, Y. Aritomo, N. Liyana, B. Yanagi, H. Hachikubo

Eurasian Journal of Physics and Functional Materials

To synthesis of superheavy elements, the shell structure is very important not only in the stability of nuclei, but also the fusion process, especially the cold fusion reaction. We employ the Langevin equation with the microscopic transport coefficients and calculate the fusion cross section for the reaction70Zn+208Pb→278Cn. In the dynamical process, the effect of nuclear structure is discussed.

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