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Sethi M.,Shoolini University of Biotechnology and Management Sciences | Varun,National Institute of Technology Hamirpur | Thakur N.S.,National Institute of Technology Hamirpur
Solar Energy | Year: 2012

An experimental investigation has been carried out for a range of system and operating parameters in order to analyse the effect of artificial roughness on heat transfer and friction characteristics in solar air heater duct which is having dimple shaped elements arranged in angular fashion (arc) as roughness elements on absorber plate. Duct has an aspect ratio (W/H) of 11, relative roughness pitch (p/e) range of 10-20, relative roughness height (e/D h) range of 0.021-0.036, arc angle (α) range of 45-75° and Reynolds number (Re) ranges from 3600 to 18,000. A considerable increase in heat transfer and friction loss has been observed. The experimental data have been used to develop Nusselt number and friction factor correlations as a function of roughness parameters and operating parameters. © 2012 Elsevier Ltd.

Sareen R.,Shoolini University of Biotechnology and Management Sciences
Current drug delivery | Year: 2013

In the present investigation chitosan microspheres loaded with flurbiprofen (FLB) were prepared by oil/oil emulsification method for colon specific drug delivery. FLB was entrapped in chitosan microspheres, following coating with Eudragit S-100 utilizing the benefits of pH dependent solubility of Eudragit S-100, so as to prevent the premature release of FLB in upper GIT. Different batches of FLB microspheres were prepared by varying FLB: chitosan ratio (1:1 to 1:4). The effect of chitosan concentration on size, entrapment efficiency, percent drug loading and degree of swelling was evaluated. DSC studies revealed the dispersion of FLB in the matrix of chitosan microspheres. SEM analysis indicated the nearly smooth surface and spherical shape of the prepared microspheres. X-ray diffract gram of FLB microspheres showed less intense peaks as compared to free FLB. In vitro release studies of uncoated FLB- chitosan microspheres showed burst release in initial 4 h, while Eudragit S-100 coated microspheres prevented the premature release of FLB and showed controlled release for 12 h following Higuchi model, thus suitable for colon specific drug delivery.

Chauhan R.,Shoolini University of Biotechnology and Management Sciences | Thakur N.S.,National Institute of Technology Hamirpur
Energy | Year: 2014

Jet impingement is an established method of convective heat transfer from the heated surface to the carrier fluid. High heat transfer rates are achieved using impinging jets in solar air heater duct but at the cost of increased friction power penalty. This paper presents thermohydraulic performance of impinging jet solar air heater in the form of effective efficiency and compared the same with that of conventional solar air heater. The study has been carried out to study the effect of Reynolds number, diameter of the jet, streamwise and spanwise pitch on effective efficiency. Based upon the study, it has been concluded that impinging jet solar air heater performs better than the conventional solar air heater for specified range of Reynolds number. The effective efficiency has been computed based upon the correlations developed by the investigators and maximum effective efficiency of 70% has been achieved for impinging jet solar air heater in the range of investigated system and operating parameters. Also, based upon the study, the design plots have been prepared for each jet parameter with temperature rise parameter in order to obtain optimum effective efficiency for desired value of temperature rise. © 2014 Elsevier Ltd.

Zhu Z.,Frederick National Laboratory for Cancer Research | Singh V.,Frederick National Laboratory for Cancer Research | Singh V.,Shoolini University of Biotechnology and Management Sciences | Watkins S.K.,Frederick National Laboratory for Cancer Research | And 4 more authors.
Cancer Research | Year: 2013

One obstacle in eliciting potent antitumor immune responses is the induction of tolerance to tumor antigens. TCRlo mice bearing a TCR transgene specific for the melanoma antigen tyrosinase-related protein-2 (TRP-2, Dct) harbor T cells that maintain tumor antigen responsiveness but lack the ability to control melanoma outgrowth. We used this model to determine whether higher avidity T cells could control tumor growth without becoming tolerized. As a part of the current study, we developed a second TRP-2-specific TCR transgenic mouse line (TCRhi) that bears higher avidity T cells and spontaneously developed autoimmune depigmentation. In contrast to TCRlo T cells, which were ignorant of tumor-derived antigen, TCRhi T cells initially delayed subcutaneous B16 melanoma tumor growth. However, persistence in the tumor microenvironment resulted in reduced IFN-g production and CD107a (Lamp1) mobilization, hallmarks of Tcell tolerization. IFN-g expression by TCRhi T cells was critical for upregulation of MHC-I on tumor cells and control of tumor growth. Blockade of PD-1 signals prevented T-cell tolerization and restored tumor immunity. Depletion of tumor-associated dendritic cells (TADC) reduced tolerization of TCRhi T cells and enhanced their antitumor activity. In addition, TADCs tolerized TCRhi T cells but not TCRlo T cells in vitro. Our findings show that T-cell avidity is a critical determinant of not only tumor control but also susceptibility to tolerization in the tumor microenvironment. For this reason, care should be exercised when considering T-cell avidity in designing cancer immunotherapeutics. © 2012 AACR.

Pathania D.,Shoolini University of Biotechnology and Management Sciences | Sharma R.,Shoolini University of Biotechnology and Management Sciences
Advanced Materials Letters | Year: 2012

The graft copolymerization of methacrylic acid onto gelatinized potato starch has been carried out at 70° C using chromic acid as initiator. The different reaction parameters such as effect of temperature, initiator and monomer concentrations were optimized to determine the maximum percentage grafting. The maximum grafting efficiency of 87.5% was optimized at reaction temperature (60°C), monomer concentration (0.81molL-1) and initiator concentration (0.02 mmol.L-1). The grafted samples were evaluated for other physico-chemical properties such as swelling behavior, moisture absorption and chemical resistance. The grafted samples were characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA) techniques. The additional peaks observed in FTIR spectra of grafted samples confirmed the grafting of monomer onto gelatinized starch. The grafted co-polymers have been successfully used for the removal metal ions and organic dyes from aqueous system. © 2012 VBRI Press.

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