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1.
Tanu Sharma Sanjeev Aggarwal Shyam Kumar V. K. Mittal P. C. Kalsi V. K. Manchanda 《Journal of Materials Science》2007,42(4):1127-1130
The UV-Visible absorption spectra of virgin and gamma irradiated (20–800 kGy) CR-39 polymer have been deduced by using Shimadzu
Double beam Double Monochromator UV-Visible Spectrophotometer (UV-2550). The existence of the peaks, their shifting and broadening
as a result of gamma irradiation has been discussed. Finally the indirect and direct band gap in virgin and gamma irradiated
CR-39 has been determined. The values of indirect band gap have been found to be lower than the corresponding values of direct
band gap. 相似文献
2.
Achintya Kumar Sen Bibha Mukherjee A. S. Bhattacharya L. K. Sanghi P. P. De Anil K. Bhowmick 《应用聚合物科学杂志》1991,43(9):1673-1684
An attempt is made to develop a novel series of cable sheathing compounds with variation in chlorine content and sufficient fire retardance and unique low-smoke characteristics. These are prepared by blending PVC and functionalized polyolefins in different compositions. PE and EPDM have been functionalized by grafting dibutyl maleate (DBM) using DCP as initiator. FRLS compounds made from PVC-functionalized polyolefin blends possess the special characteristics of low-smoke, low-acid-gas generation, increased fire retardance, and improved volume resistivity, which are much better in comparison with a typical PVC sheathing compound. Thermoplastic elastomer (TPE) based nonhalogen FRLS compounds are also reported. The mechanisms for grafting, polymer-polymer and polymer-filler interactions have been presented. 相似文献
3.
Huddar Mahesh G. Sannakki Sanjeev S. Rajpurohit Vijay S. 《Multimedia Tools and Applications》2021,80(9):13077-13077
Multimedia Tools and Applications - A Correction to this paper has been published: https://doi.org/10.1007/s11042-021-10591-y 相似文献
4.
Suruchi Poddar Piyush Sunil Agarwal Ajay Kumar Sahi Neelima Varshney Kiran Yellappa Vajanthri Sanjeev Kumar Mahto 《应用聚合物科学杂志》2021,138(24):50569
The present study reports for first time the blending of psyllium husk (PH) powder/gelatin (G) in the polymer-rich composition of polyvinyl alcohol (PVA) to make an electrospinnable solution. The composite was prepared in 3 different ratios viz., 100% (wt/wt) (PVA + PH), 75% + 25% (PVA + 75PH + 25G) (wt/wt) and 50% + 50% (PVA + 50PH + 50G) (wt/wt) in 6% PVA solution. Optimum electrospinning parameters were evaluated for all the prepared blends. The fabricated nanofibers were characterized by scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared, differential scanning calorimetry, porosity percentage, and fiber orientation using ImageJ software. A qualitative in vitro degradation study at room temperature is supported by SEM images. The cellular interactions were characterized by MTT assay of NIH-3T3 fibroblast cells for 2 and 4 days with an optimum cell growth of >50% by fourth day of culture and long-term cultivation of L929-RFP cells was observed for 10 days. The nanofibers were formed in the range of 49–600 nm. PVA + 75PH + 25G when cultured with L929-RFP cells exhibited highest fluorescence intensity and thus supported cellular proliferation significantly. Based on the results obtained from various analyses, we anticipate that fabricated psyllium-based nanofiber can be used as a promising candidate for wound healing and other biomedical applications. 相似文献
5.
6.
Accuracy improvement method for flank milling surface design 总被引:2,自引:2,他引:0
Chenggang Li Sanjeev Bedi Stephen Mann 《The International Journal of Advanced Manufacturing Technology》2008,38(3-4):218-228
In this paper, a variation of the method of designing surfaces for flank milling proposed by Li et al. 2006 (Surface design for flank milling. Submitted to CAD, July) is presented. Li’s method is based on the premise that the surface flank milled by a cylindrical tool can be represented by a NURBS surface and can be used by designers to build efficient impellers, blades and other engineering parts. In the proposed method, a four control point curve is used to approximate the grazing curves and for subsequent generation of a polynomial surface. This eliminates the need of weights for the interior control points and still results in a good surface. The accuracy of the surface can be controlled by adding control points. Examples are given to demonstrate the proposed surface design method. 相似文献
7.
The present research is the first type of study in which the application of powder mixed electrical discharge machining (PMEDM) for the machining of β-phase titanium (β-Ti) alloy has been proposed. β-Ti alloys are new range of titanium alloys, which has a wide-spread application in dental, orthopedics, shape memory, and stents. The aim of the present study is to fabricate submicro- and nanoscale topography by PMEDM process to enhance the biocompatibility without affecting machining efficiency. The effect of Si powder concentration along with pulse current and duration on the surface and machining characteristics has been investigated. A significant decrease in surface crack density on the machined surface with 4 g/l Si powder concentration was observed. When β-Ti alloy was modified at 15 A pulse current, longer pulse interval with 8 g/l concentration of Si powder particles, the interconnected surface porosities with pore size 200–500 nm was observed. Moreover, at Si powder concentrations of 2 g/l and 4 g/l, the recast layer thickness is 8 µm and 2–3 µm, respectively. Elemental mapping analysis confirmed that PMEDM also generated carbides and oxides enriched surface, a favorable surface chemistry to enhance the biocompatibility of β-Ti alloy. Furthermore, PMEDM also enhances the machining performance by improving material removal rate and reducing tool wear rate. 相似文献
8.
Sanjeev K Srivastava Alireza Aghajamali 《Journal of Superconductivity and Novel Magnetism》2017,30(2):343-351
In the present work, reflectance properties of one-dimensional photonic crystal (1D PC) containing a metamaterial and high-temperature superconductor have been investigated theoretically and analyzed. The reflectance/transmittance spectrum of the proposed structure is obtained by using the characteristic or transfer-matrix method (TMM). The results show that by increasing the thickness of the metamaterial layer, the width of the second reflection band decreases while the width of the first reflection band remains almost the same though it shifts towards the higher frequency side. In addition to this, a new band gap arises in the lower side of frequency. But, when the thickness of the superconductor layer is increased, the width of both the bands increases and no additional band arises in this case. Moreover, the reflection band is also affected by varying the operating temperature of the superconducting layer and the results show that bands get narrower by increasing the operating temperature. Finally, the effect of incident angle on the reflection band has been discussed for both transverse electric (TE) and transverse magnetic (TM) polarizations. 相似文献
9.
Cost of software testing can be reduced by automated test data generation to find a minimal set of data that has maximum coverage. Search-based software testing (SBST) is one of the techniques recently used for automated testing task. SBST makes use of control flow graph (CFG) and meta-heuristic search algorithms to accomplish the process. This paper focuses on test data generation for branch coverage. A major drawback in using meta-heuristic techniques is that the CFG paths have to be traversed from the starting node to end node for each automated test data. This kind of traversal could be improved by branch ordering, together with elitism. But still the population size and the number of iterations are maintained as the same to keep all the branches alive. In this paper, we present an incremental genetic algorithm (IGA) for branch coverage testing. Initially, a classical genetic algorithm (GA) is used to construct the population with the best parents for each branch node, and the IGA is started with these parents as the initial population. Hence, it is not necessary to maintain a huge population size and large number of iterations to cover all the branches. The performance is analyzed with five benchmark programs studied from the literature. The experimental results indicate that the proposed IGA search technique outperforms the other meta-heuristic search techniques in terms of memory usage and scalability. 相似文献
10.
Sanjeev Saxena 《Information Processing Letters》2010,110(4):168-170
In this paper a linear time algorithm is proposed for preprocessing the edges of a graph. After preprocessing (in linear time), the fundamental cut set of any tree edge can be determined in time proportional to the size of that cut set. 相似文献