Structural, elastic, and electronic properties of newly discovered Li2PtSi3 superconductor: Effect of transition metals

First-principles calculations within the density functional theory (DFT) with GGA-PBE exchange-correlation scheme have been employed to predict the structural, the elastic and the electronic properties of newly discovered lithium silicide superconductor, Li2PtSi3, for the first time. All the theoretical results are compared with those calculated recently for isostructural Li2IrSi3. The present study sheds light on the effect of replacement of transition metal element Ir with Pt on different mechanical, electronic, and superconducting properties. The effect of spin-orbit coupling on electronic band structure was found to be insignificant for Li2PtSi3. The difference in superconducting transition temperatures of Li2PtSi3 and Li2IrSi3 arises primarily due to the difference in electronic energy density of states at the Fermi level. Somewhat reduced Debye temperature in Li2PtSi3 plays a minor role. We have discussed the implications of the theoretical results in details in this study.Comment: Submitted for publicatio

Clear Experimental Signature of Charge-Orbital density wave in Nd1−x_{1-x}Ca1+x_{1+x}MnO4_{4}

Single Crystals of Nd$_{1-x}$Ca$_{1+x}$MnO$_{4}$ have been prepared by the travelling floating-zone method, and possible evidence of a charge -orbital density wave in this material presented earlier [PRB68,092405 (2003)] using High Resolution Electron Microscopy [HRTEM] and Electron Diffraction [ED]. In the current note we present direct evidence of charge-orbital ordering in this material using heat capacity measurements. Our heat capacity measurements indicate a clear transition consistent with prior observation. We find two main transitions, one at temperature $T_{_H}=310-314$ K, and other at $T_{_A}=143$ K. In addition, we may also conclude that there is a strong electron-phonon coupling in this material.Comment: 7 pages, 8 figure

Micro structure and Fractography of Multiwalled Carbon Nanotube Reinforced Unsaturated Polyester Nanocomposites

In this study unsaturated polyester resin (UPR) was reinforced with different concentration of predispersed multiwalled carbon nanotube (MWCNT). The rheology, structural analysis, fracture behavior, morphology, and thermal analysis of nanocomposites were carried out as a function of MWCNT content. Shear thinning behavior exhibited distinguishable dispersion quality of 0.3 wt% MWCNT in UPR matrix. Structural analysis reveals that MWCNT enhanced the nucleation of nanocomposites. The crystallinity of nanocomposites was increased by 71% after incorporation of 0.3 wt% MWCNT. Bending strength (BS) and bending modulus (BM) of nanocomposites were increased as well as 0.3 wt% MWCNT exhibited crack shielding in nanocomposites.The glass transition (Tg) and melting transition (Tm) of nanocomposites was increased by 68C and 108C respectively as compare to neat UPR. Additionally thermal stability of 0.3 wt% MWCNT incorporated nanocomposites was significantly improved as compare to UPR and nanocomposites which contained 0.1 and 0.5 wt% MWCN

Case studies of six CBFM-2 water bodies

The case studies report on how CBFM-2 interventions have affected aquatic productivity, income, employment and livelihoods in six case study sites, Beelbhora beel cluster (Kishoreganj), Sholuar beel (Narail), Chapundaha beel (Rangpur), Hamil beel (Tangail), Kutir beel (Kishoreganj) and Dikshi beel (Pabna).

Pattern of dyslipidemia in hypothyroid patients: A cross sectional study

Background: An association between thyroid dysfunction and dyslipidemia prevails. Levels of total cholesterol, low density lipoprotein cholesterol, triglycerides tend to increase as thyroid function declines.Objective: To find out the pattern of dyslipidemia in hypothyroid patients. Methods: Sixty cases were selected as a sample of convenience in this cross sectional study from in-patienl depa1tment of Medicine and Endocrinology, BSMMU. Meticulous history taking and thorough clinical examinations were done. Report of lipid profile and thyroid function tests were recorded from patients file. All the information's were recorded in a pre-designed sttuctured questionnaire. Collected data were classi­fied, edited, coded and entered into the computer for statistical analysis by using SPSS. Results: Among the 60 cases, 43 (72%) were female; 17(28%) were male. Age range was 24-59 years with a mean age of 38.80 (± I 0.35) years. Majority 38(65%) were housewife, followed by service holder 11(18.33%), 08(13.3%) were business men and 02(3.3%) had other occupations. Majority 42(70%) patients were taking thyroxin. Mean Total cholesterol (TC), LDL cholesterol, Triglycer­ide (TG) and HDL were 222.20(±42.25); 138.63(±31.51); 243.36(±83.13) and 37.30(±5.12) respectably. Conclusion: All hypothyroid subjects had dyslipidemia. The present study indicated that hypothyroidism was associated with an abnormal lipid profile, especially with respect to the levels of total cholesterol and triglyceride

A single LC tank based active voltage balancing circuit for battery management system

Nowadays, battery operated vehicles and machine power tools are becoming popular due to their simple and compact structure, low operating and maintenance costs, moreover renewable energy utilization facility etc. In order to obtain the necessary operating voltage and current of these devices, many electric cells are combined together in series and parallel combination. A series battery balancing circuit can be used to improve the efficiency of each cell charging and discharging process and consequently increase the lifespan of it. A battery management system (BMS) needs an efficient balancing circuit. This paper presents a high-speed single LC-tank DC to DC converter based electric cell balancing schemes. Since the supercapacitors are equivalent of rechargeable battery; in this research two supercapacitors have been used instead of rechargeable batteries. The voltage balance has been maintained by charging and discharging the supercapacitors through a single LC-tank circuit. As a result, the overall voltage balancing time has been reduced and improved the circuit performance. Experimental result shows that the proposed balancing circuit can reduce the voltage difference between the two supercapacitors from 350 mV to 0 V in 284 seconds, which is less time than the existing system. Satu pengubah resonan sesiri telah direka bagi mengimbangi aras voltan pada kenderaan beroperasikan bateri dan pada mesin jana kuasa yang menjadi semakin popular.Ini kerana strukturnya yang mudah dan kompak, kos operasi dan penyelenggaraan yang rendah, termasuk kemudahan penggunaan tenaga kitar semula dan sebagainya. Bagi mendapatkan voltan dan arus operasi yang sesuai, banyak sel elektrik telah digabungkan bersama dalam gabungan sesiri dan selari. Litar pengimbang bateri sesiri boleh digunakan bagi meningkatkan kecekapan setiap proses pengecasan dan penyahcas sel dan sekaligus meningkatkan jangka hayat sel. Sistem pengurusan bateri (BMS) memerlukan litar pengimbang yang cekap. Kertas ini membentangkan tentang satu pengubah DC-DC tangki-LC berkelajuan tinggi berdasarkan skim pengimbang sel elektrik. Oleh kerana supercapacitors bertindak seperti bateri boleh cas semula; penyelidikan ini telah mengguna pakai dua super-kapasitor dan bukan bateri boleh cas semula. Baki voltan telah dikekalkan dengan mengecas dan menyahcas super-kapasitor menggunakan satu litar tangki-LC. Dengan ini, masa pengimbang keseluruhan voltan dapat dikurangkan dan kecekapan litar dapat ditingkatkan. Hasil eksperimen menunjukkan litar pengimbang yang dicadangkan dapat mengurangkan perbezaan voltan antara dua super-kapasitor dari 350 mV kepada 0 V dalam tempoh 284 saat, kurang daripada masa sistem sedia ada

Design and Development of a Single Channel Analyzer with Microcontroller Based Controlled Output

Single Channel Analyzer (SCA) is a most common device used in today\u27s nuclear world. Therefore, A SCA with microcontroller based controlled output has been proposed in this article. The system comprises of Lower Level Discriminator (LLD), Upper Level Discriminator (ULD), wide dynamic range, Fast Processing and Hysteresis. The Comparator LM339N used as the key component that performs the main function of the proposed nuclear module. The multi-turn potentiometers have been used as LLD and ULD for the incoming linear pulses from shaping amplifier. The system has also employ the Hysteresis facilities so that oscillations due to stray feedback are not possible. A lower pin and less housing PIC microcontroller (P16F676) has been used to control the width and time delay of the output pulses