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.

Facile Synthesis of Bio-Composite Films Obtained from Sugarcane Bagasse and Cardboard Waste

Sanjeev Makin,Satish Kumar Singh,Sweety Verma,Himanshu Gupta,Avneesh Kumar Gehlaut,Suantak Kamsonlian,Surya Narain Lal,Ankur Gaur 한국화학공학회 2023 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.61 No.4

In this study, we focus on the recycling of cardboard waste and sugarcane bagasse (SCB) for the preparation of carboxymethyl cellulose (CMC) and its conversion into a biodegradable film. Sodium alginate (SA) was added to form a biodegradable composite film. SA was used to increase film permeability. Glycerol, which is a plasticizer, was used to increase the tensile strength (TS) and film expansion. To characterize the CMC, X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy were used. The addition of olive oil to the CMC-SA matrix highlighted its antimicrobial property against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). A slight decrease in tensile strength was observed with the addition of olive oil (OO), which improved the functional properties of the control films as well as lowered moisture content and water solubility. But considering all other factors, the composite films obtained from sugarcane bagasse and cardboard waste incorporated with olive oil are suitable for applications in the field of food packaging.

Design, Simulation, Fabrication, Packaging and Testing of an AlGaAs/GaAs Gunn Diode at 94 GHz

Sanjeev K. Sharma,김득영 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.67 No.4

An AlGaAs/GaAs heterostructure Gunn diode was designed, simulated and fabricated at 94 GHz. First, the Gunn diode was simulated by using SILVACO in vertical mode. Thereafter, it was fabricated by using Cl2-based dry etching, metallization and MESA etching with controlled anode diameters. Current-voltage measurements were performed on the fabricated Gunn diode at room temperature, and the results closely matched with the results of the simulation. The current oscillation with transit time was simulated and found to be a coherent oscillation at 100 GHz. The peak current increased from 0.63 to 0.86 A and the oscillation amplitude increased from 75.21 to 98.09 mA as the diameter of the anode was increased from 62 to 70 μm while the threshold voltage was observed to be constant at 2.9 V. The simulation results were observed to be in good agreement with the experiment results.

Role of Heavy Metal Resistant Ochrobactrum sp. and Bacillus spp. Strains in Bioremediation of a Rice Cultivar and Their PGPR Like Activities

Sanjeev Pandey,Pallab Kumar Ghosh,Sisir Ghosh,Tarun Kumar De,Tushar Kanti Maiti 한국미생물학회 2013 The journal of microbiology Vol.51 No.1

The present study demonstrates the metal toxicity ameliorating and growth promoting abilities of three different bacterial isolates when applied to rice as host plant. The three bacterial strains included a cadmium resistant Ochrobactrum sp., a lead resistant Bacillus sp. and an arsenic resistant Bacillus sp. designated as CdSP9, PbSP6, and AsSP9, respectively. When these isolates were used as inocula applied to metaltreated rice plants of variety Satabdi, the germination percentage, relative root elongation (RRE), amylase and protease activities were increased. The toxic effect of metal was reduced in presence of these bacteria. The overall biomass and root/shoot ratio were also enhanced by bacterial inoculation. Hydroponic studies showed that the superoxide dismutase (SOD) activity and malondialdehyde (MDA) level, which had been increased in the presence of metal stress in rice roots, were lowered by the bacterial inoculation. In addition, all three strains were 1-aminocyclopropane-1-carboxylate (ACC) deaminase and catalase positive, whereas siderophore producing ability was lacking in PbSP6. However, both PbSP6 and AsSP9 were protease positive and could hydrolyse starch. The data indicate that these bacteria have promise for bioremediation as well as for plant growth promotion.

Influence of Cutting Parameters on Tool Wear and Surface Roughness in Hard Turning of AISI H11 Tool Steel using Ceramic Tools

Sanjeev Saini,Inderpreet Singh Ahuja,Vishal S. Sharma 한국정밀공학회 2012 International Journal of Precision Engineering and Vol. No.

In machining of parts, surface quality is one of the most specified customer requirements. Major indication of surface quality on machined parts is surface roughness. There are various machining parameters which have an effect on the surface roughness, but these effects have not been adequately quantified. In order for manufacturers to maximize their gains from utilizing finish hard turning, accurate predictive models for surface roughness and tool wear must be constructed. This paper utilizes response surface methodology (RSM) for modeling to predict surface roughness and tool wear for variety of cutting conditions in finish hard turning. The experimental data obtained from performed experiments in finish turning of hardened AISI H-11 steel have been utilized. Decrease in feed rate and increase in cutting speed resulted in significant increase in surface quality. However, increase in cutting speed also produced relatively higher tool wear. Also depth of cut did not significantly affect the tool wear and surface roughness.

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.

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.

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.

Expression of procaspase 3 and activated caspase 3 and its relevance in hormone-responsive gallbladder carcinoma chemotherapy

( Sanjeev Kumar Maurya ),( Mallika Tewari ),( Bechan Sharma ),( Hari Shanker Shukla ) 대한내과학회 2013 The Korean Journal of Internal Medicine Vol.28 No.5

Background/Aims: The higher incidence of gallbladder cancer (GBC) in females has been accredited to the involvement of hormones. The clinical implications of sex hormone receptors in GBC are well established. Cysteine proteases (such as caspase-3-9, etc.) are known to play a central role in the apoptotic pathway. Of these, the downstream enzyme caspase-3 is often activated in the apoptotic pathway. The aim of this work was to examine the status of apoptosis (which directly correlated with the level of active caspase-3) in hormone-responsive GBC. Methods: We used 10 androgen receptor (AR)-positive, 14 estrogen receptor (ER)-positive, 12 HER/neu-positive, eight triple positive, and 10 triple negative malignant GBC human tissue samples. We isolated the total cellular protein from tumor tissues and carried out Western blotting using antipro-caspase-3 and anti-activated caspase-3 antibodies. Results: ER and HER/neu-positive GBC exhibited high caspase-3 activity and low procaspase-3 activity, whereas AR-positive GBC showed no significant level of apoptosis. We also evaluated the apoptosis status of triple positive GBC and triple negative GBC, and found significant apoptosis in triple positive GBC. Conclusions: The results indicate that ER and HER/neu-positive GBCs had active apoptosis, whereas AR-positive GBC was highly resistant to apoptosis.

A hybrid Taguchi-artificial neural network approach to predict surface roughness during electric discharge machining of titanium alloys

Sanjeev Kumar,Ajay Batish,Rupinder Singh,T. P. Singh 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.7

In the present study, electric discharge machining process was used for machining of titanium alloys. Eight process parameters werevaried during the process. Experimental results showed that current and pulse-on-time significantly affected the performance characteristics. Artificial neural network coupled with Taguchi approach was applied for optimization and prediction of surface roughness. Theexperimental results and the predicted results showed good agreement. SEM was used to investigate the surface integrity. Analysis formigration of different chemical elements and formation of compounds on the surface was performed using EDS and XRD pattern. Theresults showed that high discharge energy caused surface defects such as cracks, craters, thick recast layer, micro pores, pin holes, residualstresses and debris. Also, migration of chemical elements both from electrode and dielectric media were observed during EDS analysis. Presence of carbon was seen on the machined surface. XRD results showed formation of titanium carbide compound which precipitatedon the machined surface.