243 research outputs found

    Determination of optimal tool path in drilling operation using Modified Shuffled Frog Leaping Algorithm

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    Applications like boilerplates, food-industry processing separator, printed circuit boards, drum and trammel screens, etc. consists of a matrix of a large number of holes. The primary issue involved in hole-making operations is a tool travel time. It is often necessary to find the optimal sequence of operations so that the total processing cost of hole-making operations can be minimized. In this work, therefore an attempt is made to reduce the total tool travel of hole-making operations by applying a relatively new optimization algorithm known as modified shuffled frog leaping for determining the optimal sequence of operations. Modification is made in the existing shuffled frog-leaping algorithm by introducing three parameters with their positive values to widen the search capability of existing algorithms. A case study of the printed circuit board is considered in this work to demonstrate the proposed approach. Obtained results of optimization using modified shuffled frog leaping algorithm are compared with those obtained using particle swarm optimization, firefly algorithm and shortest path search algorithm

    A multifunctional phosphite-containing electrolyte for 5 V-class LiNi 0.5Mn1.5O4 cathodes with superior electrochemical performance

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    We report a highly promising organophosphorus compound with an organic substituent, tris(trimethylsilyl)phosphite (TMSP), to improve the electrochemical performance of 5 V-class LiNi0.5Mn 1.5O4 cathode materials. Our investigation reveals that TMSP alleviates the decomposition of LiPF6 by hydrolysis, effectively eliminates HF promoting Mn/Ni dissolution from the cathode, and forms a protective layer on the cathode surface against severe electrolyte decomposition at high voltages. Remarkable improvements in the cycling stability and rate capability of high voltage cathodes were achieved in the TMSP-containing electrolyte. After 100 cycles at 60 ??C, the discharge capacity retention was 73% in the baseline electrolyte, whereas the TMSP-added electrolyte maintained 90% of its initial discharge capacity. In addition, the LiNi 0.5Mn1.5O4 cathode with TMSP delivers a superior discharge capacity of 105 mA h g-1 at a high rate of 3 C and an excellent capacity retention of 81% with a high coulombic efficiency of over 99.6% is exhibited for a graphite/LiNi0.5Mn1.5O 4 full cell after 100 cycles at 30 ??C.close8

    Blunt abdominal trauma: the experience in rural India and review of literature

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    Background: Blunt Abdominal trauma is one of the most common injuries caused due to road traffic accidents. The rapid increase in number of motor vehicles and its aftermath has caused rapid increase in number of victims due to blunt abdominal trauma. As the care of patients with blunt abdominal injuries is largely a surgical responsibility and abdominal injuries involving major hemorrhage from solid viscera constitute surgical emergencies. Abdominal blunt traumas represent a real diagnostic and therapeutic challenge to even a most experienced surgeon, thereby representing importance of its study. Early diagnosis and effective management help in decreasing mortality in blunt abdominal trauma.Methods: Prospective study of 50 patients admitted to the institute with history of Blunt Abdominal Trauma. After initial resuscitation of the patients, thorough assessments for injuries were carried out in all the patients. Documentation of patients, which included identification, history, clinical findings, diagnostic test, operative findings, operative procedures and complications during the stay in the hospital were all recorded on a Performa specially prepared. The management was decided depending upon history, clinical examination and investigations.Results: Males were predominantly affected, and most cases were between the age group of 21-40 years (76%). Majority of the patients (90%) presented with the complaint of abdominal pain followed by abdominal distension (56%). 36(60%) patients were managed conservatively while operative interventions were required in 24(40%) patients. The common surgeries performed in the patients included splenectomy, primary closure of perforation and resection and anastomosis of bowel. Majority of the patients (80%) were discharged within 20 days of admission. The mortality in present study was 13.3%.Conclusions: Blunt Abdominal Trauma is one of the important causes of morbidity and mortality in young adults. Immediate resuscitative measures, management of associated injuries and appropriate operative intervention are important parts of management of such cases

    Optimal sequence of hole-making operations using particle swarm optimization and modified shuffled frog leaping algorithm

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    Tool travel and tool switch scheduling are two major issues in hole-making operations. It is necessary to find the optimal sequence of operations to reduce the total processing cost of hole-making operations. In this work therefore, an attempt is made to use both a recently developed particle swarm optimisation algorithm and a shuffled frog leaping algorithm demonstrating in this way an example of plastic injection mould. The exact value of the minimum total processing cost is obtained by considering all possible combinations of sequences. The results obtained using particle swarm optimisation and shuffled frog leaping algorithm are compared with the minimum total processing cost results obtained by considering all possible combinations of sequences. It is observed that the results obtained using particle swarm optimisation and shuffled frog leaping algorithm are closer to the results of the minimum total processing cost obtained by considering all possible combinations of sequences presented in this work. This clearly shows that particle swarm optimisation and shuffled frog leaping algorithm can be effectively used in optimisation of large scale injection mould hole-making operations

    Quantifying Capacity Loss due to Solid-Electrolyte-Interphase Layer Formation on Silicon Negative Electrodes in Lithium-ion Batteries

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    Charge lost per unit surface area of a silicon electrode due to the formation of solid-electrolyte-interphase (SEI) layer during initial lithiation was quantified, and the species that constitute this layer were identified. Coin cells made with Si thin-film electrodes were subjected to a combination of galvanostatic and potentiostatic lithiation and delithiation cycles to accurately measure the capacity lost to SEI-layer formation. While the planar geometry of amorphous thin films allows accurate calculation of surface area, creation of additional surface by cracking was prevented by minimizing the thickness of the Si film. The cycled electrodes were analyzed with X-ray photoelectron spectroscopy to characterize the composition of the SEI layer. The charge lost due to SEI formation measured from coin cell experiments was found to be in good agreement with the first-cycle capacity loss during the initial lithiation of a Si (100) crystal with planar geometry. The methodology presented in this work is expected to provide a useful practical tool for battery-material developers in estimating the expected capacity loss due to first cycle SEI-layer formation and in choosing an appropriate particle size distribution that balances mechanical integrity and the first cycle capacity loss in large volume expansion electrodes for lithium-ion batteries.Comment: 15 pages, 9 figures; Journal of Power Sources, 201

    Floating tablets of hydralazine hydrochloride: optimization and evaluation

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    Hydralazine hydrochloride has a half-life of 2 to 4 hours with an oral bioavailability of 26-50%. Since hydralazine has a demethylating effect on various suppressor genes, it can be used in various types of cancer to support chemotherapy. The purpose of this study was to optimize and evaluate floating tablets of hydralazine hydrochloride designed to prolong the gastric residence time and to provide controlled release of the drug for 14 h. The floating tablets of hydralazine hydrochloride were prepared by the wet granulation method. Semi-synthetic polymers of hydroxy propyl methyl cellulose (HPMC K100M) and ethyl cellulose were used as the release retarding agents. A 2² factorial design was applied to systematically optimize the drug release profile. The concentrations of HPMC K100M and ethyl cellulose were optimized to provide controlled release of hydralazine for 14h. Non-Fickian diffusion release transport was confirmed as the release mechanism for the optimized formulation and the predicted values agreed well with the experimental values. Drug excipient compatibility studies were investigated by FTIR, DSC and XRD. These data indicate that there were no chemical interactions between the drug and the polymer. In vivo X-ray imaging showed floating tablet performance in rabbits
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