The closed-loop control of coupled inductor-based high-step-up-gain boost converter in continuous conduction mode has non-minimum phase behavior due to right-half-plane (RHP) zero. The crossover ...frequency of the closed loop should be designed to be less than RHP zero for stable converter operation. Hence, the converter has lower bandwidth (BW) and a poor dynamic response. Combining the interleaving technique with coupled inductor boost converter (CIBC) can improve the dynamic response. As the number of interleaved phases at the input side of CIBC increases, RHP zero moves toward higher frequency. Thus, it improves the closed-loop BW. In addition, it is simple and easy to design closed loop of interleaved coupled inductor boost converter (ICIBC). Moreover, an interleaved operation reduces the size of inductance required for the same ripple in input current and reduces voltage dip during a step change in load. This paper presents a small-signal model of a multi-phase ICIBC to verify the claim. The laboratory prototype of CIBC and three-phase ICIBC is implemented to boost 24 V to 100 V at power level of 300 W. The experimental results of CIBC and three-phase ICIBC are obtained for a change in load from 150 to 300 W to validate results of small-signal model. A single-loop voltage mode control with Type II controller is implemented to regulate output voltage and to achieve desired dynamic performance of three-phase ICIBC for a load disturbance.
Annexin A1 (ANXA1) has an important role in cell-cell communication in the host defense and neuroendocrine systems. In both systems, its actions are exerted extracellularly via membrane-bound ...receptors on adjacent sites after translocation of the protein from the cytoplasm to the cell surface of adjacent cells. This study used molecular, microscopic, and pharmacological approaches to explore the mechanisms underlying the cellular exportation of ANXA1 in TtT/GF (pituitary folliculo-stellate) cells. LPS caused serine-phosphorylation of ANXA1 (ANXA1-S²⁷-PO₄) and translocation of the phosphorylated protein to the cell membrane. The fundamental requirement of phosphorylation for membrane translocation was confirmed by immunofluorescence microscopy on cells transfected with wild-type or mutated (S²⁷/A) ANXA1 constructs tagged with enhanced green fluorescence protein. The trafficking of ANXA1-S²⁷-PO₄ to the cell surface was dependent on PI3-kinase and MAP-kinase. It also required HMG-coenzyme A and myristoylation. The effects of HMG-coenzyme A blockade were overcome by mevalonic acid (the product of HMG-coenzyme A) and farnesyl-pyrophosphate but not by geranyl-geranylpyrophosphate or cholesterol. Together, these results suggest that serine-27 phosphorylation is essential for the translocation of ANXA1 across the cell membrane and also identify a role for isoprenyl lipids. Such lipids could target consensus sequences in ANXA1. Alternatively, they may target other proteins in the signal transduction cascade (e.g., transporters).--Solito, E., Christian, H. C., Festa, M., Mulla, A., Tierney, T., Flower, R. J., Buckingham, J. C. Post-translational modification plays an essential role in the translocation of annexin A1 from the cytoplasm to the cell surface.
This paper proposes new Non-Isolated Interleaved (NII) DC–DC converter for distributed generation system to step-up voltage level of photovoltaic unit. Three winding coupled inductors (TWCIs), ...voltage tripler rectifier and voltage multiplier are integrated to derive this converter to achieve high step-up voltage gain with lower turns ratio and duty ratio. The key feature of this converter is low voltage stress on switching devices compared to existing TWCIs NII topologies for similar gain. Input side interleaved structure is employed to reduce input current ripple and to increase power density. The proposed converter can transfer energy of Coupled Inductor (CI) to output capacitors in forward and flyback modes, therefore converter can eliminate effect of right-half-plane zero. This converter can achieve high bandwidth and improve dynamic response. Three windings of CI are wound using bifilar and interleaving methods to reduce leakage inductance, therefore lossless passive clamp circuit is sufficient to recover leakage energy of CI. In this paper, operational principles and steady-state analysis of proposed topology is discussed. Small-signal-model of this converter is derived. Performance analysis and operation of proposed topology are verified via experimental results of a 250 W, 24 V input to 350 V output laboratory prototype. Single loop voltage control of this converter is implemented to achieve regulated output voltage and to further enhance dynamic response.
The present work focuses on the synthesis of fattythioic acids (FTAs) by a one-step lipase catalyzed reaction of palm oil with carbonothioic S,S-acid using Lipozyme. The product was characterized ...using Fourier transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance (1H NMR) technique and elemental analysis. The effects of various reaction parameters such as reaction time, temperature, amount of enzyme, molar ratio of substrates, and various organic solvents of the reaction system were investigated. The optimum conditions to produce FTAs were respectively, incubation time, 20 h, temperature, 40°C, amount of enzyme, 0.05 g and molar ratio of carbonothioic S,S-acid to palm oil, 5.0:1.0. Hexane was the best solvent for this reaction. The conversion of the products at optimum conditions was around 91%.
•Enhanced building operations were applied for eight large government buildings in Kuwait.•The enhanced building operations led to demand savings of 8.90MW during the national peak hour.•Nationwide ...guidelines were developed for implementing the enhanced operations in similar government buildings in Kuwait.•The peak electrical demand reduction is likely to be 488MW by the year 2030.
An approach for managing electrical demand through enhanced building operations in hot climates is evaluated and demonstrated in this paper. The approach focuses on implementing enhanced operations in government buildings, since they are easier to implement and administer. These enhanced operations included early reduction of cooling supply before the end of the occupancy period, improved time-of-day control after occupancy period and reduced lighting. A total of eight government buildings with different construction and system characteristics were selected for implementing these enhanced operations. These buildings have a total air-conditioning area of 4.39×105m2 and a combined peak electrical demand of 29.3MW. The enhanced operations resulted in demand savings of 8.90MW during the national peak hour. Temperatures build up inside the buildings were monitored and found to be within acceptable ranges.
Guidelines for nationwide implementation in similar buildings were developed based on the results of this work. Implementation is estimated to reduce demand by 488MW by the year 2030, which amounts to capital savings of $585 million. These projected values would be important to adopt energy efficient policies for the country. Additional reductions in energy and fuel consumption are added benefits, which would result in large financial and environmental savings to the country. Moreover, the enhanced building operations would be an important tool to avoid any blackouts by properly reducing the peak electrical demand as well as operating the power plants with a higher thermal efficiency.
A new grafted polymer electrode (GPE) (polystyrene as polymer) was grafted with acrylonitrile as a monomer using gamma irradiation to produce a new grafted polymer. The redox process of K
3
Fe(CN)
6
...during cyclic voltammetry was studied by the new GPE. The ratio of
I
pc/
I
pa >1 of GPE to GCE
I
pc/
I
pa = 1.7, indicating that this electrode is a reversible electrode and can be used in conductivity studies by voltammetric analysis. The physical properties of the new electrode GP have good hardness, insolubility, and stability at different high temperatures and at different pH. Also, the sensitivity under conditions of cyclic voltammetry is significantly dependent on pH, electrolyte, and scan rate. At different scan rates, two oxidation peaks and two reduction peaks of Fe(III) were observed in a reversible process: Fe(III) Fe(II), and Fe(II) Fe(0). Interestingly, the redox reaction of Fe(III) solution using GPE remained constant even after 15 cycles. It is therefore evident that the GPE possesses some degree of stability. The potential use of the grafted polymer as a useful electrode material is therefore clearly evident.
In this study, new biopolymer nanocomposites have been prepared. Fatty nitrogen compounds (FNCs); fatty amide (FA), fatty hydroxamic acid (FHA), and carbonyl difatty amide (CDFA), which were ...synthesized from palm oil, have been used as one of organic compounds to modify natural clay (sodium montmorillonite). The clay modification was carried out by stirring the clay particles in an aqueous solution of FA, FHA, and CDFA by which the clay layer distance increases from 1.23 to 2.71, 2.91 and 3.23 nm, respectively. The modified clay was then used in the preparation of the polylactic acid/epoxidized palm oil (PLA/EPO) blend nanocomposites. The interaction of the modifier in the clay layer was characterized by X-ray diffraction (XRD), and Fourier transform infrared (FTIR). Elemental analysis was used to estimate the presence of FNCs in the clay. The nanocomposites were synthesized by melt blending of the modified clay and PLA/EPO blend at the weight ratio of 80/20. The nanocomposites were then characterized using XRD, transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and tensile properties measurements. The XRD and TEM results confirmed the production of nanocomposites. PLA/EPO modified clay nanocomposites show higher thermal stability and significant improvement of mechanical properties in comparison with those of the PLA/EPO blend.
Hepatic toxicity of nickel chloride in mice Gathwan, Khalid H.; Al-Karkhi, Isam Hussain T.; Jaffar AL-Mulla, Emad A.
Research on chemical intermediates,
07/2013, Letnik:
39, Številka:
6
Journal Article
Recenzirano
The present study is to evaluate the toxic effects of nickel (Ni) on the liver structure of male mice. Male Balb/c mice weighing 30–32 g, 50 days old, were treated orally with 1–16 mg/kg (body wt.) ...NiCl
2
. The body weight, liver weight, histological examination of liver, and DNA ladder for apoptosis were studied. Ni induced increases in apoptotis and severity of necrosis. Liver weight and body weight decreased with increasing dose. Histological changes in the liver included hepatocyte degeneration, nuclear pycnosis, cellular swelling, and congestion of blood vessels. There was a marked difference in these changes among the different treatments of Ni concentrations in addition to the intensity of histological changes which were, however, influenced by the extent of the exposure period. It has been concluded that nickel caused apoptotis in liver of male mice.
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