Correlation between the exchange bias effect and antisite disorders in Sr2−x_{2-x}Lax_xCoNbO6_6

We unravel the effect of La substitution and hence antisite disorders on the exchange bias (EB) mechanism in Sr$_{2-x}$La$_x$CoNbO$_6$ ($x=$ 0, 0.2) double perovskite samples using the detailed analysis of the field cooled magnetization isotherms (M--H) and training effect. The field dependence of the freezing temperature deviates from both Gabay-Toulouse (GT) and de Almeida-Thouless (AT) lines and the analysis suggests that the $x=$ 0 sample follows a different universality class with moderate anisotropy in the frozen spins. Interestingly, we find that the EB effect is significantly suppressed in the $x=$ 0.2 sample due to increase [decrease] in the size of ferromagnetic (FM) [cluster glass (CG)] domain, which reduces the effective disordered interface responsible for the EB. The changes in fraction of FM, AFM, and CG like interactions with the La substitution and applied magnetic field are found to be crucial in governing the EB effect in these samples. Further, the training effect measurements show the unequal shift in the left and right branches of the M--H loops and their different evolution with the field cycles ($n$). The analysis reveals that the rotatable spins relax approximately one order of magnitude faster than the frozen spins at the disordered interface. We find a possible correlation between the observed EB effect and the antisite disorders in these samples.Comment: submitte

Design & Fabrication of Manually Driven Pedal Powered Washing Machine

Cloth washing is one of the essential parts of the life but it is considered undesirable because of the involvement of efforts, time, energy and cost. Nowadays a wide variety of washing machines are available in the market and there is a tough competence among the manufacturers. The cost of washing machine varying from Rs.10,000 to 1,50,000 depending upon features and capabilities. Very costly washing machines are equipped with facility of dry cleaning too. All of the washing machines available in the market are electric power driven and basic principle of their operation depends upon creation of the turbulent flow of detergent around the dirty clothes. Drying of the clothes is based upon rotation of wet clothes at very high rpm so that water droplets can be separated out due to centrifugal action. In our country where approximately 70% population is living with very poor economic status, those people cannot have a washing machine because of cost constraints and unavailability of electricity due to any reason. The present work is an attempt to develop a concept to make a cloth washing mechanism which can meet out the requirements of above mentioned 70% population of the nation. Working principle of this concept is no more different from available similar type of machine with a difference driving mechanism of the machine. The objective of bringing down the initial cost and operating cost of washing machine is almost achieved in present work within the limitation of work as mentioned. Key word: CWT, CEA, 1. Introductio

Ultra low power high speed domino logic circuit by using FinFET technology

Scaling of the MOSFET face greater challenge by extreme power density due to leakage current in ultra deep sub-micron (UDSM) technology. To overcome from this situation double gate device like FinFET is used which has excellent control over the thin silicon fins with two electrically coupled gate, which mitigate shorter channel effect and exponentially reduces the leakage current. In this research paper utilize the property of FinFET in domino logic, for high speed operation and reduction of power consumption in wide fan-in OR gate. Proposed circuit is simulated in FinFET technology by BISM4 model using HSPICE at 32nm process technology at 250C with CL=1pF at 100MHz frequency. For 8 and 16 input OR gate we save average power 11.5%,11.39% in SFLD, 22.97%, 18.12% in HSD, 30.90%, 34.57% in CKD in SG mode and for LP mode 11.26%, 15.78% in SFLD, 19.74%, 17.94% in HSD, 45.23%, 34.69% in CKD respectivel

STEREO SELECTIVE SYNTHESIS OF NOVEL LIGNAN INTERMEDIATES AS ANTIMICROBIAL AGENTS

Objectives: The aim of the present study was to synthesize a series of new lignan intermediates as potential antimicrobial agents.Methods: Substituted benzene and aromatic acids or acid chlorides were converted to benzophenones 1(a-f). The benzophenones 1(a-f) on Stobbe condensation with and diethyl succinate in the presence of potassium t-butoxide yielded 4-(4-aryl)-4-(4-aryl)-3-ethoxycarbonyl-but-3-enoic acids (2a, 2f) and a mixture of E and Z-isomers of 4,4-diaryl-3-ethoxycarbonyl-but-3-enoic acids 2(b-e) and 3(b-e) in relatively good yields. The synthesized compounds were tested for their antimicrobial susceptibility against different fungi and bacteria species.Results: The Stobbe condensation of benzophenones 1(a-f) and diethyl succinate in the presence of potassium t-butoxide yielded 4-(4-aryl)-4-(4-aryl)-3-ethoxycarbonyl-but-3-enoic acids (2a, 2f) and a mixture of E and Z-isomers of 4,4-diaryl-3-ethoxycarbonyl-but-3-enoic acids 2(b-e) and 3(b-e) in good yields. The compounds 1a and 1f yielded only 2a and 2f but not 3a and 3f due to symmetrical substitution in the aromatic rings. The structures of the new lignan intermediates were confirmed by spectral studies and elemental analysis.Conclusions: Results of the antimicrobial activity reveal that some of the compounds particularly 2c, 2d, 3c and 3d act as potential antimicrobial agents different fungal and bacterial organisms.Â

Quarkonium spectroscopy of the linear plus modified Yukawa potential

In this article, the linear plus modified Yukawa potential (LIMYP) is used as the quark antiquark interaction potential for the approximate analytical bound state solution of the Klein Gordon equation in three-dimensional space. The energy eigenvalues and associated wavefunction are obtained by solving the Klein Gordon equation analytically using the Nikiforov Uvarov (NU) method. The mass spectra of heavy mesons such as charmonium $(c\bar{c})$, bottomonium $(b\bar{b})$, and $b\bar{c}$ for various quantum states are obtained using the energy spectra expression. In comparison to experimental data, graphical modification of acquired mass spectra of heavy mesons with the parameter employed in the energy equation and the current potential provides good results.Comment: 17 pages, 24 figures, 3 table

PSoC Based Instrumentation for H2 Sensor in the Context of Fast Breeder Reactors

To monitor very low levels of hydrogen in cover gas plenum of fast breeder reactors, thin film sensors based on tin oxide doped with palladium are developed in IGCAR. The sensor patterns are integrated on a miniature alumina substrate and necessary electrical leads are incorporated in it. The conductivity of the sensor varies with H2 concentration. The useful range of the sensor is 5 ppm to 80 ppm and the base line resistance of the sensor is around 2.5MΩ. This paper gives an outline of the PSoC based electronics developed to measure the H2 concentration and associated signal processing. Low component count and feasibility of locating the sensor conditioning components remotely are emphasized in the design. The laboratory studies on the linearity performance of the various blocks of the system are discussed