1,729 research outputs found
FESD: a Functional Element SNPs Database in human
We have created the Functional Element SNPs Database (FESD) that categorizes functional elements in human genic regions and provides a set of single nucleotide polymorphisms (SNPs) located within each area. In the FESD, the human genic regions were divided into 10 different functional elements, such as promoter regions, CpG islands, 5′-untranslated regions (5′-UTRs), translation start sites, splice sites, coding exons, introns, translation stop sites, polyadenylation signals and 3′-UTRs, and subsequently, all the known SNPs were assigned to each functional element at their respective position. With the FESD web interface, users can select a set of SNPs in the specific functional elements and get their flanking sequences for genotyping experiments, which will help in finding mutations that contribute to the common and polygenic diseases. A web interface for the FESD is freely available at http://combio.kribb.re.kr/ksnp/resd/
Physical properties of transparent perovskite oxides (Ba,La)SnO3 with high electrical mobility at room temperature
Transparent electronic materials are increasingly in demand for a variety of
optoelectronic applications. BaSnO3 is a semiconducting oxide with a large band
gap of more than 3.1 eV. Recently, we discovered that La doped BaSnO3 exhibits
unusually high electrical mobility of 320 cm^2(Vs)^-1 at room temperature and
superior thermal stability at high temperatures [H. J. Kim et al. Appl. Phys.
Express. 5, 061102 (2012)]. Following that work, we report various physical
properties of (Ba,La)SnO3 single crystals and films including
temperature-dependent transport and phonon properties, optical properties and
first-principles calculations. We find that almost doping-independent mobility
of 200-300 cm^2(Vs)^-1 is realized in the single crystals in a broad doping
range from 1.0x10^19 to 4.0x10^20 cm^-3. Moreover, the conductivity of ~10^4
ohm^-1cm^-1 reached at the latter carrier density is comparable to the highest
value. We attribute the high mobility to several physical properties of
(Ba,La)SnO3: a small effective mass coming from the ideal Sn-O-Sn bonding,
small disorder effects due to the doping away from the SnO2 conduction channel,
and reduced carrier scattering due to the high dielectric constant. The
observation of a reduced mobility of ~70 cm^2(Vs)^-1 in the film is mainly
attributed to additional carrier-scatterings which are presumably created by
the lattice mismatch between the substrate SrTiO3 and (Ba,La)SnO3. The main
optical gap of (Ba,La)SnO3 single crystals remained at about 3.33 eV and the
in-gap states only slightly increased, thus maintaining optical transparency in
the visible region. Based on these, we suggest that the doped BaSnO3 system
holds great potential for realizing all perovskite-based, transparent
high-frequency high-power functional devices as well as highly mobile
two-dimensional electron gas via interface control of heterostructured films.Comment: 31 pages, 7 figure
Influence of Polypyrrole on Phosphorus- and TiO2-Based Anode Nanomaterials for Li-Ion Batteries
Phosphorus (P) and TiO2 have been extensively studied as anode materials for lithium-ion batteries (LIBs) due to their high specific capacities. However, P is limited by low electrical conductivity and significant volume changes during charge and discharge cycles, while TiO2 is hindered by low electrical conductivity and slow Li-ion diffusion. To address these issues, we synthesized organic–inorganic hybrid anode materials of P–polypyrrole (PPy) and TiO2–PPy, through in situ polymerization of pyrrole monomer in the presence of the nanoscale inorganic materials. These hybrid anode materials showed higher cycling stability and capacity compared to pure P and TiO2. The enhancements are attributed to the electrical conductivity and flexibility of PPy polymers, which improve the conductivity of the anode materials and effectively buffer volume changes to sustain structural integrity during the charge and discharge processes. Additionally, PPy can undergo polymerization to form multi-component composites for anode materials. In this study, we successfully synthesized a ternary composite anode material, P–TiO2–PPy, achieving a capacity of up to 1763 mAh/g over 1000 cycles
Performance-Based Multiobjective Optimal Seismic Retrofit Method for a Steel Moment-Resisting Frame Considering the Life-Cycle Cost
This study proposes a performance-based multiobjective optimization seismic retrofit method for steel moment-resisting frames. The brittle joints of pre-Northridge steel moment-resisting frames are retrofitted to achieve ductility; the method involves determining the position and number of connections to be retrofitted. The optimal solution is determined by applying the nondominated sorting genetic algorithm-II (NSGA-II), which acts as a multiobjective seismic retrofit optimization technique. As objective functions, the initial cost for the connection retrofit and lifetime seismic damage cost were selected, and a seismic performance level below the 5% interstory drift ratio was employed as a constraint condition. The proposed method was applied to the SAC benchmark three- and nine-story buildings, and several Pareto solutions were obtained. The optimized retrofit solutions indicated that the lifetime seismic damage cost decreased as the initial retrofit cost increased. Although every Pareto solution existed within a seismic performance boundary set by a constraint function, the seismic performance tended to increase with the initial retrofit cost. Analysis and economic assessment of the relations among the initial retrofit cost, lifetime seismic damage cost, total cost, and seismic performance of the derived Pareto solution allow building owners to make seismic retrofit decisions more rationally
Improvement of Strength and Oxidation Resistance at High Temperature in AISI 4140 Steel by Micro-Alloying Chromium and Tungsten for Automotive Engine Applications
Increasing the operating temperature and pressure of an automotive engine and reducing its weight can improve fuel efficiency and lower carbon dioxide emissions. These can be achieved by changing the engine piston material from conventional aluminum alloy to high-strength heat- resistant steel. American Iron and Steel Institute 4140 modified steels (AISI 4140 Mod.s), which have improved strength, oxidation resistance, and wear resistance at high temperature were developed by adjusting the AISI 4140 alloy compositions and optimizing the heat treatment process for automotive engine applications. In this study, the effects of modifying alloy compositions on the microstructure, mechanical properties (both at room and high temperatures), and oxidation of AISI 4140 Mod.s were investigated. Effective grain refinement occurred due to the influence of high-temperature stable carbide forming elements such as Mo, and V. The bainite structure changed to martensite structure under the influence Cr and Ni. As the Cr and W contents increased, the oxidation resistance was improved, and the oxide layer thickness decreased after 10 hours exposure at 500°C. The AISI 4140 Mod. exhibited a 35% improvement in room temperature strength, 70% improvement in high-temperature strength, and 40% improvement in high-temperature oxidation resistance compared to conventional AISI 4140
Effect of Cooling Rate on Microstructure and Mechanical Properties According to Heat Treatment Temperature of Inconel 625
Inconel 625 is typically used in extreme environments due to excellent mechanical properties such as high strength, corrosion resistance, abrasion resistance and low-temperature toughness. When manufacturing a hot forged flange with a thick and complex shape, the cooling rate varies depending on the location due to the difference in thermal gradient during the cooling process after hot forging. In this study, to evaluate the microstructure and mechanical properties of Inconel 625 according to the cooling rate, we performed heat treatment at 950°C, 1050°C, and 1150°C for 4 hours followed by water cooling. Additionally, temperature data for each location on the flange were obtained using finite element method (FEM) simulation for each heat treatment temperature, revealing a discrepancy in the cooling rate between the surface and the center. Therefore, the correlation between microstructure and mechanical properties according to cooling rate was investigated
High Prevalence of Peripheral Arterial Disease in Korean Patients with Coronary or Cerebrovascular Disease
This prospective study surveyed the prevalence of peripheral arterial disease (PAD) in Korean patients with coronary arterial disease (CAD) or cerebrovascular disorder (CVD). From March 2010, 576 hospitalized patients in cardiovascular or stroke center were enrolled as the study group. Ankle-brachial index (ABI) was measured and the cut-off point for diagnosing PAD was ≤ 0.9 at rest. A total of 424 hospitalized patients in the Department of Surgery and aged ≥ 50 yr was enrolled as the control group. The prevalence of PAD was significantly higher in the study group than the control group (7.6% vs 1.7%; P < 0.001). To analyze the relationship of other vascular diseases and PAD, the patients were regrouped; group A (no CAD or CVD), group B (CAD only), group C (CVD only), and group D (CAD and CVD). Compared with group A, those with other vascular diseases (group B, C, D) had significantly higher prevalence of PAD, diabetes, dyslipidemia, renal insufficiency and claudication. The trend that patients with CAD or CVD are at risk of PAD is observed in this cross-sectional study in Koreans. Routine ABI measurement is recommended in these high-risk groups for early detection and proper management of PAD
Teatro e ensino da matemática: atividade desenvolvida num curso de formação docente
Anais do II Seminário Seminário Estadual PIBID do Paraná: tecendo saberes / organizado por Dulcyene Maria Ribeiro e Catarina Costa Fernandes — Foz do Iguaçu: Unioeste; Unila, 2014Este trabalho relata uma aula desenvolvida pelas alunas do Curso de Formação de Docentes
do Instituto Estadual de Educação de Londrina com a colaboração dos Bolsistas do Programa
Institucional de Bolsas de Iniciação à Docência – PIBID – Subprojeto de Matemática, para alunos de
primeiro ano do Ensino Fundamental utilizando o teatro como forma de apresentar conteúdos
matemáticos como números, sequência de números, operações básicas como adição, subtração e
conteúdos de lÃngua portuguesa como leitura e escrita de número
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