Numerical Simulation on the Gas Explosion Propagation Related to Roadway

AbstractBased on the combustion, explosions and air dynamics and related theory etc, this paper describes the mathematical model of gas explosion in detail, combined with the gas explosion transmission mechanism, make a research on two wave-three area structure of gas explosion and the energy change rule of the array face of precursor wave and the array face of flame wave, with the fluid dynamics analysis Fluent software, this paper makes a numerical simulation and analysis on the overpressure transmission rule when gas explosion takes place in different types roadways. The results of the study show that: Fluent software can be used to accurately simulate gas explosion condition, when explosion wave spreads in the roadway turns, the bigger of the overpressure value in corner, the stronger of the destructive power; when tunnel has bifurcation, the overpressure will release in bifurcation, but explosions wave with flame wave will produce more powerful destruction effect. The research results can be used as a certain reference for how to prevent and control the gas explosion, and how to reduce the power of the gas explosion etc

Electrospun Polymer Nanomaterials: Preparation, Characterization, and Application

This paper seeks to answer, a solution, a need for improvement in the company manifested Motors Auto Import SAC It is part of the evaluation of the level of competitiveness achieved by the company Import Auto Motors in 2015, after it was developed to level the strategic direction and proposed a set of initiatives aimed at improving the competitiveness of the company. They have participated in the investigation 14 employees of Auto Motors Import, who were administered the questionnaire and interview to obtain information related to the study variable as it was considered as part of the population to major customers of the company occasionally visit the company to receive a service auto repair shop. We used non-experimental design contrasting cross one box and the data analysis using descriptive statistics ago. The research results have established that the level of competitiveness of Auto Motors Import of Trujillo in the current year is low, the main weaknesses and threats that do not have a manager in charge of ensuring growth the company and the indiscriminate increase in small oleocentros that offer very reasonable price maintenance, as well as the increase in informal technical workshops. And the strengths and opportunities of the company are to have financial capacity and long-term debt and development agreements with corporate and public and private institutions. 8 From this we have developed a level of proposed strategic direction for the company and a series of initiatives aimed at improving the competitiveness of Auto Import Motors in the city of TrujilloTesisEl presente trabajo busca responder, con una solución, a una necesidad de mejora manifestada en la empresa Auto Motors Import S.A.C. Se parte de la evaluación del nivel de competitividad alcanzado por la empresa Auto Motors Import en el año 2015, a partir de ello se ha desarrollado a nivel de propuesta el direccionamiento estratégico y un conjunto de iniciativas orientadas a mejorar la competitividad de la empresa. Han participado en la investigación 14 colaboradores de la empresa Auto Motors Import, a quienes se les aplicó el cuestionario y a 6 clientes corporativos la entrevista para obtener información referida a la variable de estudio como también se consideró como parte de la población a los principales clientes que ocasionalmente visitan la empresa para recibir un servicio del taller mecánico automotriz. Se ha utilizado el diseño de contrastación no experimental transversal de una sola casilla y para el análisis de los datos se hace uso de la estadística descriptiva. Los resultados de la investigación han permitido determinar que el nivel de competitividad alcanzado por la empresa Auto Motors Import de la ciudad de Trujillo en el año 2015 es bajo, siendo una de las principales debilidades y amenazas que no cuenta con un gerente encargado de velar por el crecimiento de la empresa y el incremento indiscriminado de pequeños oleocentros que brindan precio muy módicos en mantenimientos, así como el incremento de talleres técnicos informales. Y las fortalezas y oportunidades que presenta la empresa son que cuenta con capacidad económica y de endeudamiento a largo plazo y el desarrollo de convenios con corporativos e instituciones públicas y privadas. A partir de ello se ha elaborado a nivel de propuesta el direccionamiento estratégico para la empresa y un conjunto de iniciativas orientadas a mejorar la competitividad de la empresa Auto Motors Import en la ciudad de Trujillo

Multi-heterostructure composites of Fe3O4 coated Janus nanoparticles and MWCNTs with high microwave absorption

Microwave-absorbing materials with heterostructure represent a major challenge and opportunity in enabling strong microwave absorption over a wide bandwidth. Here, novel hydrophilic multi-heterostructure composites (Mag@J/MWCNT) were fabricated by combining nanostructured Fe3O4 covered snowman-like Janus nanoparticles (Mag@J) with MWCNTs for enhanced microwave absorption. The good hydrophilicity and low reflection loss (RL) demonstrated the potential application of Mag@J as an effective microwave absorbent with environmentally friendly processibility. Further, the multi-heterostructure composites constructed by Mag@J (with 77.73 wt% Fe3O4) and MWCNTs exhibited strong absorption intensity (RL = −38.98 dB), wide bandwidth (6.04–8.23 GHz), and low thickness (3.5 mm). The excellent microwave absorption properties were attributed to the strong dielectric loss, magnetic loss, and good impedance matching of different components in multi-heterostructure composites, as well as multiple reflection absorption of microwave in the hollow sphere of Janus particle. Therefore, this work provides important inspiration for multi-heterostructure composites to achieve potential applications as electromagnetic wave absorbing materials

Failure Analysis Of Gate-All-Around Nanowire Field Effect Transistor Under Tlp Test

Electrostatic discharge (ESD) characters of Nanowire Field Effect Transistors have been tested and analyzed in detail in this paper. TLP (transmission line pulsing technique) and semiconductor characterization system have been used for experiments. The failure currents and leakage currents of Nanowire Field Effect Transistor are characterized. Also, physical insights and failure model are provided to analyze the failure mechanism

Enthalpy-Enhanced Janus Nanosheets for Trapping Nonequilibrium Morphology of Immiscible Polymer Blends

Janus particles are promising for self-assembly at the liquid/liquid interface due to coexistence of the Pickering effect and the different wettability of both sides. In this study, we synthesize a Janus nanosheet and evaluate its ability to trap nonequilibrium morphology by interfacial self-assembly. The Janus nanosheet was synthesized by selectively grafting polymer chains, polystyrene (PS) or polyisoprene (PI), on each side of a silica nanosheet. The selective grafting method endow the nanosheet with two different wettabilities, which make it ideal for self-assembly and further jamming at the PS/PI interface. The interfacial jamming of the nanosheet trapped the intermediate, nonequilibrium morphology during phase separation of the polymer blends. Compared to other Janus materials, the Janus nanosheet has higher interfacial activity and reduces the free energy of the system more effectively due to its 2D structure. Only 2 wt % of Janus nanosheet is required to break the threshold and reach the jammed state. The Janus nanosheet is easily scaled up and has potential as a compatibilizer in polymer materials

Synthesis of Janus Rubber Hybrid Particles and Interfacial Behavior

In this paper, Janus hybrid particles with rubber brushes have been first fabricated by successively grafting polybutadiene chains onto polydivinylbenzene (PDVB) side and polyisoprene chains onto SiO₂ side in the case of SiO₂@PDVB Janus particles as the template. The weight grafting ratios (<i>G</i>_r) of polybutadiene (PBd) and polyisoprene (PI) brushes were determined as 19.4 and 24.8 wt %, respectively. Such Janus hybrid particles contribute to not only the retardation of phase separation but also the kinetically trapped bicontinuous phase morphology in rubber blends. The interface jamming of these Janus particles supports their promising applications as compatibilizers in polymer blends

PTEN: an emerging target in rheumatoid arthritis?

Abstract Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a critical tumor suppressor protein that regulates various biological processes such as cell proliferation, apoptosis, and inflammatory responses by controlling the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (PI3K/AKT) signaling pathway. PTEN plays a crucial role in the pathogenesis of rheumatoid arthritis (RA). Loss of PTEN may contribute to survival, proliferation, and pro-inflammatory cytokine release of fibroblast-like synoviocytes (FLS). Also, persistent PI3K signaling increases myeloid cells’ osteoclastic potential, enhancing localized bone destruction. Recent studies have shown that the expression of PTEN protein in the synovial lining of RA patients with aggressive FLS is minimal. Experimental upregulation of PTEN protein expression could reduce the damage caused by RA. Nonetheless, a complete comprehension of aberrant PTEN drives RA progression and its interactions with other crucial molecules remains elusive. This review is dedicated to promoting a thorough understanding of the signaling mechanisms of aberrant PTEN in RA and aims to furnish pertinent theoretical support for forthcoming endeavors in both basic and clinical research within this domain