Modeling of thermodynamic properties of an oxygenate + aromatic hydrocarbon: Excess molar enthalpy

Sanjeev Maken,Manju Rani,Sanjeev Maken,권휘웅,탁경재,문일 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.23 No.-

Excess molar enthalpy ðHEm Þ have been measured at 303.15 K for 1-propanol + benzene or toluene or o- or m- or p-xylene mixtures using flow micro calorimeter. The HEm versus x1 plots are skewed toward y-axis showing maxima at x1 0:3. At ðx1 ¼ 0:5Þ HEm vary in the order: toluene < benzene < m-xylene < pxylene o-xylene. The excess volume data have also been interpreted in terms of Graph-theoretical approach and Prigogine–Flory–Patterson theory. It has been observed that while PFP theory fails to predict the HEm values for these systems in the composition range x1 < 0:5, agreement with experimental values is reasonably good thereafter. The HEm values calculated by Graph theory compared well with the corresponding experimental values.

Synthesis and characterization of hybrid Ag-ZnO nanocomposite for the application of sensor selectivity

Sanjeev K. Sharma,Gajanan S. Ghodake,김득영,김대영,O.P. Thakur 한국물리학회 2018 Current Applied Physics Vol.18 No.4

Facile, rapid, and environmentally benign hybrid Ag-ZnO nanocomposites were synthesized by two steps from green synthesis approach at room temperature. The absence of an impurity peak in X-ray diffraction (XRD) pattern confirmed the formation of polycrystalline nanocomposite material. An additional peak (111) of Ag was detected along with ZnO crystalline wurtzite structure. The surface area electron diffraction (SAED) pattern further confirmed the crystallinity of nanocomposites. The compositional analysis of hybrid Ag-ZnO was determined by EDS-mapping and confirmed the presence of Zn, O and Ag in the composite. The room-temperature photoluminescence (PL) spectra of hybrid Ag-ZnO depict a weak ultraviolet (UV) emission at 385 nm, and the strong visible emission at ~600 nm, while increasing the Ag concentration in to ZnO matrix, the UV peak was completely disappeared and major visible peak was moved to ~500 nm indicated to the best optimal detection peak for sensors. The fluorescence spectra were measured with respect to Ag concentrations of Ag-ZnO nanocomposite at room temperature to investigate the functionality and the selectivity of nanomaterials. This work opens a notable way to fabricate Ag-ZnO nanohybrids, and makes a significant contribution to the fluorescence based sensor applications.

EXERGY ANALYSIS OF A LiBr–H2O VAPOR ABSORPTION REFRIGERATION PLANT: A CASE STUDY

SANJEEV ANAND,ANKUSH GUPTA,SUDHIR KUMAR TYAGI 대한설비공학회 2014 International Journal Of Air-Conditioning and Refr Vol.22 No.2

This communication presents the energy and exergy analysis of an actual double effect steampowered LiBr–H2O vapor absorption refrigeration plant. Exergy loss, COP, exergy efficiency andheat rate for each component of the system are calculated. The effect of generator as well asevaporator temperature on the COP and exergy efficiency is evaluated and it is found that theirreversibility rate is highest in the generator while it is found to be the lowest in the case ofabsorber and condenser. It is also found that the COP of the system increases with the increase inthe evaporator temperature while it is found to be reverse in case of exergy efficiency. Resultsrevealed that average exergy loss is highest in the generator as compared to other components. The results obtained are helpful for designers to bring changes in the actual system for performance optimization and less wastage of energy. The study clearly explain the operational andmaintenance problems in the machine and point out the areas of energy wastage which theoperational engineer should look into for the optimum operation of the plant.

Environmental Stability and Correlation of Soybean Seed Starch with Protein and Oil Contents

Sanjeev K. Dhungana,Krishnanand P. Kulkarni,김민수,하보근,강성택,송종태,신동현,이정동 한국육종학회 2017 Plant Breeding and Biotechnology Vol.5 No.4

Seed starch content (SSC) is a decisive factor influencing soy food quality. Variation in SSC affects the composition of major components, oil, and protein in soybean seeds. Therefore, understanding G × E interaction of SSC is important to produce soybeans with stable SSC. In the present study, G × E interactions of 17 soybean genotypes having different SSC (0.24-1.48%) and correlation of SSC with crude protein (CP) and crude fat (CF) were investigated. The genotypes were evaluated for SSC and other traits at two planting dates across three locations over two years (2015 and 2016). The genotype × year, genotype × location, and genotype × year × location interactions were found to be significant (P ≤ 0.001) for SSC, CP, and CF. The average SSC content was found to be higher in 2015 than in 2016. Late planted soybeans contained higher SSC than the early planting soybeans. The SSC was negatively affected by the average daily mean and minimum temperatures and cloudiness during the pod-filling stage. Based on the mean rank, IT189276 (1.39%) was observed to be the most stable genotype among the high starch containing soybeans. Significant (P ≤ 0.0001) negative correlations were found between SSC and CP as well as CP and CF contents. However, a significant (P ≤ 0.05) positive correlation was observed between SSC and CF content. Results of this study showed that SSC affects the seed protein and oil contents and is significantly influenced by the growing environments.

Identification and SWOT analysis of ecological and security issues of battery electric vehicles

Sanjeev Kumar,Amit Pal Techno-Press 2022 Advances in energy research Vol.8 No.3

Environmental sustainability is critical; else, the whole planet would face climatic disasters in the near future. A transportation system based on electric vehicles is assumed to be capable of providing long-term mobility. However, despite several attempts by national and international authorities, a great aim could not be met in India or the rest of the globe. Existing electric cars have a number of limits and obstacles. This report highlighted significant environmental and safety-related constraints that contribute to the low adoption rate of BEVs in India. A SWOT analysis was also carried out to identify the important elements influencing the future of BEV penetration in India.

Bridging the nanogap electrodes with gold nanoparticles using dielectrophoresis technique

Sanjeev Kumar,윤석왕,김길호 한국물리학회 2009 Current Applied Physics Vol.9 No.1

We report the assembling of 20 nm gold nanoparticles into the nanogap electrodes by dielectrophoresis (DEP) technique. DEP was performed on electrodes with different gap size values. While the frequency and the applied peak to peak voltage were maintained at 1 MHz and 3 V, respectively, DEP time was varied in accordance with electrodes gap size. Interestingly, some novel assembling was observed during the dielectrophoresis process and the nanogaps were bridged by nanoparticles either forming ring shaped bridges or linear bridges. The assembling of nanoparticles in different form is attributed to the positive DEP effect. This effect is seen to be influenced significantly by the time parameter during which DEP was performed. Results show the promise of dielectrophoresis in controlled engineering of nanoparticles assembly. We report the assembling of 20 nm gold nanoparticles into the nanogap electrodes by dielectrophoresis (DEP) technique. DEP was performed on electrodes with different gap size values. While the frequency and the applied peak to peak voltage were maintained at 1 MHz and 3 V, respectively, DEP time was varied in accordance with electrodes gap size. Interestingly, some novel assembling was observed during the dielectrophoresis process and the nanogaps were bridged by nanoparticles either forming ring shaped bridges or linear bridges. The assembling of nanoparticles in different form is attributed to the positive DEP effect. This effect is seen to be influenced significantly by the time parameter during which DEP was performed. Results show the promise of dielectrophoresis in controlled engineering of nanoparticles assembly.

PFC Bridge Converter for Voltage-controlled Adjustable-speed PMBLDCM Drive

Sanjeev Singh,Bhim Singh 대한전기학회 2011 Journal of Electrical Engineering & Technology Vol.6 No.2

In this paper, a buck DC-DC bridge converter is used as a power factor correction (PFC) converter for feeding a voltage source inverter (VSI) based permanent magnet brushless DC motor (PMBLDCM) drive. The front end of the PFC converter is a diode bridge rectifier (DBR) fed from single phase AC mains. The PMBLDCM is used to drive the compressor of an air conditioner through a three-phase voltage source inverter (VSI) fed from a variable voltage DC link. The speed of the air conditioner is controlled to conserve energy using a new concept of voltage control at a DC link proportional to the desired speed of the PMBLDC motor. Therefore, VSI operates only as an electronic commutator of the PMBLDCM. The current of the PMBLDCM is controlled by setting the reference voltage at the DC link as a ramp. The proposed PMBLDCM drive with voltage control-based PFC converter was designed and modeled. The performance is simulated in Matlab-Simulink environment for an air conditioner compressor load driven through a 3.75 ㎾, 1500 rpm PMBLDC motor. To validate the effectiveness of the proposed speed control scheme, the evaluation results demonstrate improved efficiency of the complete drive with the PFC feature in a wide range of speed and input AC voltage.

Characterizing Cell Death Events Using a Microfluidics-based Method

Sanjeev Kumar Mahto,윤태현,이석우 한국바이오칩학회 2008 BioChip Journal Vol.2 No.4

Cell death is the ultimate endpoint of the cellular life cycle, and the ability to distinguish different types of cell death (e.g., apoptosis and necrosis) has been a subject of intensive research. This paper demonstrates the suitability and efficiency of a microfluidicsbased method for characterization of cell death events. A multicompartmented microfluidic device was used to examine the types of cell death induced by cadmium ions at various concentrations. Annexin V-FITC in combination with propidium iodide was used to distinguish between viable, poptotic, and necrotic cells. The microfluidics-based method facilitates the performance of analysis of cell death on the basis of membrane alteration as well as morphological discrimination. In addition, this method shows high sensitivity and specificity, as evidenced by the quantification of the ratio of apoptotic and necrotic cells in the total population of cells.

Detection of Microcalcification Using the Wavelet Based Adaptive Sigmoid Function and Neural Network

( Sanjeev Kumar ),( Mahesh Chandra ) 한국정보처리학회 2017 Journal of information processing systems Vol.13 No.4

Mammogram images are sensitive in nature and even a minor change in the environment affects the quality of the images. Due to the lack of expert radiologists, it is difficult to interpret the mammogram images. In this paper an algorithm is proposed for a computer-aided diagnosis system, which is based on the wavelet based adaptive sigmoid function. The cascade feed-forward back propagation technique has been used for training and testing purposes. Due to the poor contrast in digital mammogram images it is difficult to process the images directly. Thus, the images were first processed using the wavelet based adaptive sigmoid function and then the suspicious regions were selected to extract the features. A combination of texture features and graylevel co-occurrence matrix features were extracted and used for training and testing purposes. The system was trained with 150 images, while a total 100 mammogram images were used for testing. A classification accuracy of more than 95% was obtained with our proposed method.

Thermodynamics of molecular interactions in binary mixtures containing associated liquids

Sanjeev Maken,Manju Rani 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.8

Experimentally measured data of excess molar volumes and enthalpies at 308.15 K for binary mixtures of formamide with 1-butanol or 2-methyl-1-propanol were fitted to the Redlich-Kister polynomial equation. Thermodynamics of molecular interaction in these mixtures was discussed using Prigogine-Flory-Patterson theory, Treszczanowicz-Benson association model and Graph theoretical approach. Extent of inter-molecular H-bonding in formamide and butanol in their binary mixtures was also reflected in their molar enthalpy of association of H-bonding ΔhH 0and association constant KH calculated from Treszczanowicz-Benson association model. All the three theories predict the excess property data reasonably well.