Micromagnetic Simulation of Spin Transfer Torque Switching of Full-Heusler Co2FeAl0.5Si0.5 Alloy Thin Elliptical Disc

AbstractWe report micromagnetic simulation of spin transfer torque (STT) switching of a thin elliptical disc made of full-Heusler Co2FeAl0.5Si0.5 alloy. The STT results in switching the direction of initial magnetization of the disc to a new state based on the spin-polarization factor (ƞ) of the material and magnitude of current density (J) applied. The value of J required for magnetization switching need to be reduced in the order of 106 A/cm2. In our simulation we obtained 3 × 105 A/cm2 as the critical current density (Jc) required for complete magnetization switching of the disc. We analyzed the effect of ƞ on magnetization switching time by reducing the value of ƞ by 0.10 from the actual value of 0.76. The decrement in ƞ results in the increment of time taken to switch the direction of magnetization. The change in switching time for variable disc thickness was also studied. This simulation result holds a key factor in the study of STT switching in spin-valve nanopillar

Controlled virtual time advancement in conjoined emulation and network simulation

Emulations of network services are more accurate than simulated models. However this is achieved at an increased computational cost. Combining emulation with simulation allows more accurate, controllable and repeatable evaluation of applications but such hybrid systems are generally not scalable. Virtual time systems attempt to provide a feasible solution by defining and controlling a virtual clock to alter an experiment’s notion of time. Previous works have motivated and explored the benefits of virtual time systems in improving the scalability of combined emulation-simulation testbeds. One such endeavor resulted in the development of TimeKeeper, an open source virtual time system for Linux. TimeKeeper has been integrated with popular network simulators ns-3, CORE and S3FNet. In this thesis, we extend it further by integrating TimeKeeper with the Extensible Mobile AdHoc Network Emulator (EMANE). We also demonstrate the broad applicability of TimeKeeper by implementing a Programmable Logic Controller (PLC) network emulation tool which can be used to emulate industrial Supervisory Control and Data Acquisition (SCADA) systems. Over the course of the design of these two case studies, we unearthed and fixed a subtle design flaw in TimeKeeper’s scheduling mechanism which could potentially starve some processes of CPU time during execution. The purpose of this thesis is twofold (1) to describe improvements to TimeKeeper’s design including the logic to ensure fair scheduling and (2) to describe two case studies which demonstrate the scalability and fidelity benefits of running emulations/simulations in close virtual synchrony under the control of TimeKeeper

DCS - The Best Platform for Automation of Process Industries

Process industries have gone through many changes over the years. Right from the microprocessors, PLC, SCADA the automation is steeply increasing. Many process industries are not properly automated. Hence man power, hazards, money spent and maintenance are also high. So in order to avoid all problems automation is very essential. Every process industry must be properly automated with DCS. Here we have come up with a proposal to automate cement mill in a cement industry using DCS with an interlock

DESIGN OF MANUFACTURING CELL IN THE COMPANY BOS Klášterec nad Ohří

Tato práce se zabývá návrhem výrobní buňky pro firmu BOS Automotive Products CZ s.r.o. v Klášterci a Ohří. Hlavním cílem této práce je navrhnout pro společnost novou univerzální výrobní buňku. Pomocí některých vhodných nástrojů, jako je analýza procesu, momentkové pozorování, matice produktové rodiny a s některými dalšími na základě literární rešerše byly analyzovány aktuální stavy procesů, které probíhají v BOS Automotive. Na základě požadavků společnosti BOS Automotive s.r.o. je pak navržena v nové univerzální buňky. Nový design výrobních buněk je reprezentován ve formě CAD modelů, stejně jako vývojovým diagramem procesů, multikriteriální analýzou a špagetovým diagramem.The work presented in this thesis is the design of a manufacturing cell for the company BOS Automotive Products CZ s.r.o. in Klasterec and Ohri. The main goal of this thesis is to design new universal manufacturing production cell for the company. Using some suitable tools such as process analysis, Moment analysis, Product family matrix, the current state processes that takes place in BOS Automotive has been analysed. with some literature review from the research works. Based on the requirements of the company BOS Automotive s.r.o. work consists of design of a new Universal manufacturing cell. The new design of the manufacturing cells is represented in the form of CAD models as well as with a process flow diagram, multi-criteria analysis and spaghetti diagrams

Rice endophytes and their potential applications

Endophytic microbial communities in crop plants are beginning to be explored. These microbes are either carried through seeds or establish colonization in the plants from soil based on chemotaxis of root exudates. Variability and diversity of endophytic bacteria and fungi have been observed in rice plants in different plant parts and growth stages. Genotypic variations are observed between Indica and Japonica. Pseudomonas, Bacillus, Streptomyces, Azospirillum, Azotobacter are some of the dominating genera of bacteria in internal tissues of rice plants. These endophytes provide benefits such as tolerance to abiotic stresses, defense against pest and diseases, nutrient solubilization and mobility. In addition, many metabolites are characterized from the endophytes that are useful in other branches of biotechnology including bioremediation. Complete characterization of microbiome of rice plants under various soil agro-climatic zones and understanding their population dynamics, co-occurrence and networking will help in identifying useful strains for developing new biofertilizers, plant growth promoting microbes and biopesticides

Bis(phosphinoselenoic amides) as versatile chelating ligands for alkaline earth metal (Mg, Ca, Sr and Ba) complexes: syntheses, structure and ε-caprolactone polymerisation

We report here a series of heavier alkaline earth metal complexes with N,N′-(ethane-1,2-diyl)bis(P,P-diphenylphosphinoselenoic amide) using two synthetic routes. In the first route, the heavier alkaline earth metal bis(trimethylsilyl)amides [M{N(SiMe3)2}2(THF)n] (M = Ca, Sr, Ba), when treated with phosphinoselenoic amine [Ph2P(Se)NHCH2CH2NHPPh2(Se)] (1), afforded the corresponding alkaline earth metal complexes of the composition [(THF)3M{Ph2P(Se)NCH2CH2NPPh2(Se)}] [M = Ca (2), Sr (3), Ba (4)]. The metal complexes 2–4 were also obtained from a one-pot reaction, where potassium phosphinoselenoic amide was generated in situ by the reaction of compound 1 and [KN(SiMe3)2], followed by the addition of the respective metal diiodides in THF at room temperature. The magnesium complex [(THF)3Mg{Ph2P(Se)NCH2CH2NPPh2(Se)}] (5) was also prepared. The solid-state structures of alkaline earth metal complexes 2–5 were established by single crystal X-ray diffraction analysis. In the solid state, all the metal complexes are monomeric but in complexes 2–4, ligand 1 is chelated in a tetra-dentate fashion to each metal ion but in complex 5, ligand 1 behaves as a bidentate ligand. Complexes 2–4 were tested as catalysts for the ring-opening polymerisation of ε-caprolactone and a high level of activity for the barium complex 4 was observed, with narrow polydispersity. We also report the synthesis and structure of the bis(amidophosphino borane) ligand [Ph2P(BH3)NHCH2CH2NHPPh2(BH3)] (6) and the corresponding barium complex [(THF)2Ba{Ph2P(BH3)NCH2CH2NPPh2(BH3)}]2 (7)

Impact of halogen-free flame retardant with varied phosphorus´s chemical surrounding on the properties of diglycidyl ether of bisphenol-A type epoxy resin: synthesis, fire behaviour, flame-retardant mechanism and mechanical properties

This work aimed to investigate the effect of two types of phosphorus-containing flame retardants (P-FRs) with different chemical surroundings (phenylphosphonate-based (PO?Ph) and phenylphosphoric-based (PO?OPh)) on the flame-retardant efficiency for diglycidyl ester of bisphenol-A type epoxy (EP) resin. The two series of P-FRs which were named as FPx and FPOx (x = 1, 2 and 3), respectively, showed reactivity with epoxy group that was examined by differential scanning calorimetry (DSC) and variable temperature FTIR spectroscopy (VT-FTIR). A comparative study between the FPx and FPOx (x = 1, 2 and 3) containing flame-retardant epoxy was carried out via investigating their flammability, thermal stability and mechanical properties. The most significant difference in flame retardancy between them was that FPx (x = 1, 2 and 3) endowed EP with a V-0 rating in UL 94 test at 5 wt% loading, while FPOx (x = 1, 2 and 3) showed no rating at such loading. Importantly, it is found that there was almost 10 times difference in the flame-retardant efficiency for EP between FPx and FPOx, though they had similar chemically molecular structures. Moreover, TGA-FTIR and TGA-MS coupling techniques (TGA, thermogravimetric analysis; MS, mass spectroscopy) were employed to study the thermal decomposition of FP1 and FPO1; the impacts of FP1 and FPO1 on the thermal decomposition of EP were studied by TGA-FTIR as well. Furthermore, an online temperature detection experiment was designed to collect the temperatures by thermocouples and infrared thermometers in the UL 94 test. Based on the above results, the flame-retardant mechanisms of FP1 and FPO1 in EP are discussed. In addition, the impact of P-FRs on mechanical properties of EP was studied by means of tensile test and dynamic mechanical analysis