Fermi–Bose Correspondence and Bose–Einstein Condensation in the Two-Dimensional Ideal Gas

The ideal uniform two-dimensional (2D) Fermi and Bose gases are considered both in the thermodynamic limit and the finite case. We derive May's Theorem, viz. the correspondence between the internal energies of the Fermi and Bose gases in the thermodynamic limit. This results in both gases having the same heat capacity. However, as we shall show, the thermodynamic limit is never truly reached in two dimensions and so it is essential to consider finite-size effects. We show in an elementary manner that for the finite 2D Bose gas, a pseudo-Bose–Einstein condensate forms at low temperatures, incompatible with May's Theorem. The two gases now have different heat capacities, dependent on the system size and tending to the same expression in the thermodynamic limit.     

Bandwidth Enhancement of a Wide Slot Antenna Using Fractal Geometry for UWB Application with Multiple Notched Bands

Wireless Personal Communications - In this paper a combination of rectangular and elliptical fractal geometry is applied on a regular hexagonal wide slot antenna fabricated using a FR4 substrate to...     

Role of Oxygen as Surface-Active Element in Linear GTA Welding Process

Although the surface-active elements such as oxygen and sulfur have an adverse effect on momentum transport in liquid metals during fusion welding, such elements can be used beneficially up to a certain limit to increase the weld penetration in the gas tungsten arc (GTA) welding process. The fluid flow pattern and consequently the weld penetration and width change due to a change in coefficient of surface tension from a negative value to a positive value. The present work is focused on the analysis of possible effects of surface-active elements to change the weld pool dimensions in linear GTA welding. A 3D finite element-based heat transfer and fluid flow model is developed to study the effect of surface-active elements on stainless steel plates. A velocity in the order of 180 mm/s due to surface tension force is estimated at an optimum concentration of surface-active elements. Further, the differential evolution-based global optimization algorithm is integrated with the numerical model to estimate uncertain model parameters such as arc efficiency, effective arc radius, and effective values of material properties at high temperatures. The effective values of thermal conductivity and viscosity are estimated to be enhanced nine and seven times, respectively, over corresponding room temperature values. An error analysis is also performed to find out the overall reliability of the computed results, and a maximum reliability of 0.94 is achieved.     

Linearized dynamic models for trajectory control of robot manipulators

To make an appropriate choice of linear model for the development of real-time control of robot manipulators, four direct linearization schemes have been studied here on the basis of computation and accuracy. Accuracy is assured in the state linearization method, whereas the rate linearization method leads to a satisfactory trade-off between computational effort and accuracy. In the case of high-velocity motions, a combination of state and rate linearization is proposed.     

Dielectrc Polarization of Animal Lung at Radio Frequencies

Dielectric properties of the inflated and deflated fceline lung in vivo were investigated at frequencies from 10 kHz to 100 MHz. A computer-controlled network analyzer and a multiring capacitive sensor were employed. It was found that in the frequency range investigated, both the dielectric constant and the conductivity of the deflated lung were higher than those of the inflated one. The analysis of the experimental data was performed using two approaches: the loss-tangent method and the curve-fitting computer program called STEPIT. It was found that in the middle band of frequencies for both inflated and deflated states of the lung, the dielectric response mainly reflects the membrane polarization of the capillary erythrocytes with possible contributions of other components, e.g., the pulmonary microphages. The dielectric relaxation time for the capillary erythrocytes in the lung is similar to that for the packed cells, which is much longer than for the erythrocytes at physiological concentrations. The dielectric parameters at low frequencies obtained using the STEPIT program differ significantly between the inflated and deflated lung. The observed dielectric data reflect at least two overlapping dispersions: of lung capillary erythrocytes and of cellular structures forming the alveoli.     

Response of calcitonin cells, parathyroid glands and bone to prolonged calcitonin administration in the Indian palm squirrel, Funambulus pennanti (Wroughton)

The administration of calcitonin (4 MRC units injected intraperitoneally daily for 42 days) caused hypocalcaemia, hypophosphataemia and a decrease in the serum acid phosphatase level in adult Indian palm squirrels, Funambulus pennanti. Hypocalcaemia and the decrease in the serum acid phosphatase level persisted up to 21 days but the hypophosphataemic effect continued throughout the experiment. The serum calcium level increased from day 28 up to day 35 and the serum acid phosphatase level reached the control level at 28 days. At the close of the experiment (42 days), both serum calcium and acid phosphatase levels were again decreased. Calcitonin-induced hypocalcaemia resulted in hypertrophy of calcitonin cells which were densely packed with secretory granules up to day 21 of the treatment. Thereafter they displayed both hypertrophy and hyperplasia till the end of the experiment. Some calcitonin cells showed degranulation after 35 and 42 days of treatment. Few lead-haematoxylin-positive calcitonin cells with collapsed membranes and pyknotic nuclei were also seen in the lumina of the thyroid follicles toweards the close of the experiment. Parathyroid chief cells showed hypertrophy from 21 to 35 days of the treatment. From day 28 to the close of the experiment they released their secretory product. After 42 days of experimental treatment a growth-promoting effect of calcitonin was observed (increase in body weight and femur weight.     

Frequency Specification Testing of Analog Filters Using Wavelet Transform of Dynamic Supply Current

Wavelet transform has the property of resolving signal in both time and frequency unlike Fourier transform. In this work, we show that time-domain information obtained from wavelet analysis of supply current can be used to test the frequency specification of analog filters efficiently. The pole/zero locations in the frequency response of analog filters shift due to change in component values with process variations. It is essential to test the filters for the shift in frequency response and fix it during production test. Wavelet analysis of supply current can be a promising alternative to test frequency specification of analog filters, since it needs only one AC stimulus and is virtually unaffected by transistor threshold variation. Simulation results on two test circuits demonstrate that we can estimate pole/zero shift with less than 3% error using only one measurement, which requires about 18 measurements in the conventional technique.Swarup Bhunia received the undergraduate degree from Jadavpur University, Calcutta, India, and the Masters degree from the Indian Institute of Technology (IIT), Kharagpur. He is currently working toward the Ph.D. degree in the Department of Electrical Engineering, Purdue University, West Lafayette, IN, USA. He has worked in the EDA industry on RTL synthesis and verification for about three years. His research interest includes design methodologies for high-performance low-power testable VLSI system, defect-based testing, noise analysis, and noise-aware design.Arijit Raychowdhury received the B.E. degree in 2001 in electronics and telecommunication engineering from Jadavpur University, India. He is currently pursuing the Ph.D. degree in electrical and computer engineering in Purdue University, West Lafayette, IN, USA. He has worked as an analog circuit designer in Texas Instruments India. His research interests include device/circuit design for scaled silicon and nonsilicon devices. He has received academic excellence awards in 1997, 2000, and 2001 and Messner Fellowship from Purdue University in 2002. Mr. Raychowdhury has been awarded the Best Student Paper Award in the IEEE Nanotechnology Conference, 2003.Kaushik Roy received the B.Tech. degree in electronics and electrical communications engineering from the Indian Institute of Technology, Kharagpur, India, and the Ph.D. degree from the Electrical and Computer Engineering Department, University of Illinois, Urbana, in 1990. He was with the Semiconductor Process and Design Center of Texas Instruments, Dallas, TX, where he worked on FPGA architecture development and low-power circuit design. He joined the electrical and computer engineering faculty, Purdue University, West Lafayette, IN, in 1993, where he is currently a Professor. His research interests include VLSI design/CAD with particular emphasis in low-power electronics for portable computing and wireless communications, VLSI testing and verification, and reconfigurable computing. He has published more than 250 papers in refereed journals and conferences, holds six patents, and is Co-Author of a book on Low Power CMOS VLSI Design (New York: Wiley). He was Guest Editor for a Special Issue on Low-Power VLSI in IEE Proceedings Computers and Digital Techniques (July 2002). Dr. Roy received the National Science Foundation Career Development Award in 1995, the IBM Faculty Partnership Award, AT&T/Lucent Foundation Award, Best Paper Awards at the 1997 International Test Conference and 2000 International Symposium on Quality of IC Design, 2003 IEEE Latin American Test Workshop, and 2003 IEEE Nano. He is on the Editorial Board of IEEE Design and Test, IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS, and IEEE TRANSACTIONS ON VLSI SYSTEMS. He was Guest Editor for a Special Issue on Low-Power VLSI in IEEE DESIGN AND TEST (1994), and for the IEEE TRANSACTIONS ON VLSI SYSTEMS (June 2000).     

Dielectric properties of breast carcinoma and the surroundingtissues

Relative permittivity of infiltrating breast carcinoma and the surrounding tissue was measured. The experiments were performed at frequencies from 20 kHz to 100 MHz at 37°C using an automatic network analyzer and an end-of-the-line capacitive sensor. Cole-Cole dielectric parameters were calculated by curve fitting using a computer program. Three main categories of tissues were considered: the central part of the tumor, the tumor surrounding tissue, and the peripheral tissue. Within each category, the large spread of the dielectric data for different specimens suggests structural and cellular inhomogeneities of the tumor tissue. However, certain consistency has been found in the dielectric relaxation time and the coefficient of the distribution of the relaxation time within each category. The results seem to indicate that RF impedance imaging can potentially be used as a diagnostic modality for the detection of human breast carcinoma     

ResearchGate and Google Scholar: how much do they differ in publications,citations and different metrics and why?

ResearchGate has emerged as a popular professional network for scientists and researchers in a very short span. Similar to Google Scholar, the ResearchGate indexing uses an automatic crawling algorithm that extracts bibliographic data, citations, and other information about scholarly articles from various sources. However, it has been observed that the two platforms often show different publication and citation data for the same institutions, journals, and authors. While several previous studies analysed different aspects of ResearchGate and Google Scholar, the quantum of differences in publications, citations, and metrics between the two and the probable reasons for the same are not explored much. This article, therefore, attempts to bridge this research gap by analysing and measuring the differences in publications, citations, and different metrics of the two platforms for a large data set of highly cited authors. The results indicate that there are significantly high differences in publications and citations for the same authors captured by the two platforms, with Google Scholar having higher counts for a vast majority of the cases. The different metrics computed by the two platforms also differ in their values, showing different degrees of correlation. The coverage policy, indexing errors, author attribution mechanism, and strategy to deal with predatory publishing are found to be the main probable reasons for the differences in the two platforms.