Authentication using Finger Knuckle Prints

Automated security is one of the major concerns of modern times. Secure and reliable authentication systems are in great demand. A biometric trait like the finger knuckle print (FKP) of a person is unique and secure. Finger knuckle print is a novel biometric trait and is not explored much for real-time implementation. In this paper, three different algorithms have been proposed based on this trait. The first approach uses Radon transform for feature extraction. Two levels of security are provided here and are based on eigenvalues and the peak points of the Radon graph. In the second approach, Gabor wavelet transform is used for extracting the features. Again, two levels of security are provided based on magnitude values of Gabor wavelet and the peak points of Gabor wavelet graph. The third approach is intended to authenticate a person even if there is a damage in finger knuckle position due to injury. The FKP image is divided into modules and module-wise feature matching is done for authentication. Performance of these algorithms was found to be much better than very few existing works. Moreover, the algorithms are designed so as to implement in real-time system with minimal changes.     

在500V电压等级的AC／DC应用中最优化平面型MOSFET与超大结MOSFET的竞争

仙童公司（Fairchild）面向开关电源市场推出了一款新型最优化高速平面型MOSFET，与通常的500V电压等级的MOSFET相比，它可以降低全方位的损耗。与市场上的超大结面积型的MOSFET相比，这种MOSFET可以减少开关损耗。而和通常的标准MOSFET器件相比，它的导通损耗则大大降低。因此这种500V电压等级的MOSFET可以和一部分超大面积型MOSFET展开市场争夺方面的竞争。     

Concept of an interlaced phased array for beam switching

A novel concept is described for feeding and phasing a large linear array of N antenna elements using only three or five feed points and phase shifters and still achieving beam switching. The idea consists of drastically reducing the number of input points by interlacing a small numer of serially fed subarrays which are suitably phased. This so-called interlaced phased array (IPA) concept was tested using an array of 15 four-element Yagi antennas with a spacing equal to 0.8 wavelengths and found feasible. Some of the distinct advantages of the IPA in comparison with a conventional system of beam switching are reduced power loss, reduced phasing errors, reduced cost, increased reliability resulting from greatly reduced number of phase shifters, and better symmetry of off-zenith beams     

The planar 6H-SiC ACCUFET: a new high-voltage power MOSFETstructure

A novel planar accumulation channel SiC MOSFET structure is reported in this paper. The problems of gate oxide rupture and poor channel conductance previously reported in SiC UMOSFETs are solved by using a buried P⁺ layer to shield the channel region. The fabricated 6H-SiC unterminated devices had a blocking voltage of 350 V with a specific on-resistance of 18 mΩ.cm² at room temperature for a gate bias of only 5 V. This measured specific on-resistance is within 2.5× of the value calculated for the epitaxial drift region (10¹⁶ cm^-3, 10 μm), which is capable of supporting 1500 V     

Enhancement of thermal effect in virally infected mammalian cells in vitro and its modification by chlorpromazine

Somatostatin receptor-expressing tumours are potential targets for therapy with radiolabelled somatostatin analogues. We have synthesized a number of such analogues in the past and identified [DOTA-dPhe1, Tyr3]octreotide (SMT 487) as the most promising candidate molecule because of its advantageous properties in cellular and in vivo tumour models. In the current paper we describe the radiotherapeutic effect of yttrium-90 labelled SMT 487 in Lewis rats bearing the somatostatin receptor-positive rat pancreatic tumour CA 20948. SMT 487 binds with nanomolar affinity to both the human and the rat somatostatin receptor subtype 2 (sst2) (human sst2 IC50=0.9 nM, rat sst2 IC50=0.5 nM). In vivo, 90Y-SMT 487 distributed rapidly to the sst2 expressing CA 20948 rat pancreatic tumour, with a tumour-to-blood ratio of 49.15 at 24 h post injection. A single intravenous administration of 10 mCi/kg 90Y-SMT 487 resulted in a complete remission of the tumours in five out of seven CA 20948 tumour-bearing Lewis rats. No regrowth of the tumours occurred 8 months post injection. Control animals that were treated with 30 microg/kg of unlabelled SMT 487 had to be sacrificed 10 days post injection due to excessive growth or necrotic areas on the tumour surface. Upon re-inoculation of tumour cells into those rats that had shown complete remission, the tumours disappeared after 3-4 weeks of moderate growth without any further treatment. The present study shows for the first time the curative potential of 90Y-SMT 487-based radiotherapy for somatostatin receptor-expressing tumours. Clinical phase I studies with yttrium-labelled SMT 487 have started in September 1997.     

Functional reconstitution of protein ion channels into planar polymerizable phospholipid membranes

We demonstrate that polymerizable planar membranes permit reconstitution of protein ion channels formed by the bacterial toxins Staphylococcus aureus alpha-hemolysin (alphaHL) and Bacillus anthracis protective antigen 63. The alphaHL channel remained functional even after membrane polymerization. Surface pressure measurements suggest that the ease of forming membranes depends on membrane surface elasticity estimated from Langmuir-Blodgett monolayer pressure-area isotherms. The ability to stabilize nanoscale pores in robust ultrathin films may prove useful in single molecule sensing applications.     

Role of Chain Entanglements in the Electrospinning of Wheat Protein-Poly(Vinyl Alcohol) Blends

The aim of this investigation was to determine if the rapid solvent removal evaporation that occurs during electrospinning enabled the gluten protein and poly(vinyl alcohol) (PVOH) chains to remain at least partially entangled in the final product. Natural and synthetic biopolymer blends are known to phase separate in the melt. Differential scanning calorimetry (DSC) was used to test our hypothesis, which we achieved by systematically comparing the thermal profiles of the nonwoven fibrous sheets comprising: 1) 100% commercial wheat gluten, 2) 100% PVOH, and 3) the (75/25) wheat gluten/PVOH blend. The DSC scans of the two PVOH-containing, nonwoven fibrous sheets exhibited differences in the characteristics and positions of the melting peaks (T_m) of the PVOH crystalline phase, while the DSC scans of the nonwoven fibrous sheets comprising either 100% commercial wheat gluten or the wheat gluten/PVOH blend yielded neither a measurable glass transition temperature (T_g) nor a T_m. Energy dispersive spectroscopy (EDS) was used to compare the elemental compositions of the individual fibers with the compositions of the spherical domains found in the nonwoven fibrous mats. These scans revealed that the mineral matter found in commercial wheat gluten (roughly 1% by weight) had phase-separated from the bulk gluten protein as a result of electrospinning.     

A simple single-step approach towards synthesis of nanofluids containing cuboctahedral cuprous oxide particles using glucose reduction

Enhancement of thermal properties of conventional heat transfer fluids has become one of the important technical challenges. Since nanofluids offer a promising help in this regard, development of simpler and hassle free routes for their synthesis is of utmost importance. Synthesis of nanofluids using a hassle free route with greener chemicals has been reported. The single-step chemical approach reported here overcomes the drawbacks of the two-step procedures in the synthesis of nanofluids. The resulting Newtonian nanofluids prepared contained cuboctahedral particles of cuprous oxide and exhibited a thermal conductivity of 2.852 W·m^-1·K^-1. Polyvinylpyrrolidone (PVP) used during the synthesis acted as a stabilizing agent rendering the nanofluid a stability of 9 weeks.