85 research outputs found
Use of Wiener’s diffusion model in economic planning
No full textDiscusses the application of Wiener’s diffusion model as applied in engineering and physics. Shows how the model can be used in dealing with problems that arise in economic planning. Describes the scope of cybernetic thinking in the problems of planning in the Indian context. Gives details of the model’s application in this connection for the trends in growth levels of gross domestic product (GDP). Outlines its application to a problem of regional development.</jats:p
Redox-Responsive Nanocapsules for the Spatiotemporal Release of Miltefosine in Lysosome: Protection against Leishmania
No full textLeishmaniasis, a vector-borne disease, is caused by intracellular parasite Leishmania donovani. Unlike most intracellular pathogens, Leishmania donovani are lodged in parasitophorous vacuoles and replicate within the phagolysosomes in macrophages. Effective vaccines against this disease are still under development, while the efficacy of the available drugs is being questioned owing to the toxicity for nonspecific distribution in human physiology and the reported drug-resistance developed by Leishmania donovani. Thus, a stimuli-responsive nanocarrier that allows specific localization and release of the drug in the lysosome has been highly sought after for addressing two crucial issues, lower drug toxicity and a higher drug efficacy. We report here a unique lysosome targeting polymeric nanocapsules, formed via inverse mini-emulsion technique, for stimuli-responsive release of the drug miltefosine in the lysosome of macrophage RAW 264.7 cell line. A benign polymeric backbone, with a disulfide bonding susceptible to an oxidative cleavage, is utilized for the organelle-specific release of miltefosine. Oxidative rupture of the disulfide bond is induced by intracellular glutathione (GSH) as an endogenous stimulus. Such a stimuli-responsive release of the drug miltefosine in the lysosome of macrophage RAW 264.7 cell line over a few hours helped in achieving an improved drug efficacy by 200 times as compared to pure miltefosine. Such a drug formulation could contribute to a new line of treatment for leishmaniasis.A. Das acknowledges SERB (India) Grants (CRG/2020/000492 and JCB/2017/000004) and DBT Grant (BT/PR22251/NNT/28/1274/2017) for supporting this research. N. Mukherjee acknowledges SERB (India) Grant PDF/2016/001437 and K. Das acknowledges the grant EMR/2015/001674 for supporting this research. Financial support from DST (DST/INSPIRE/03/2017/002477) is acknowledged by R.T. This manuscript bears CSMCRI registration no 7/2021.Pramanik, SK (corresponding author), CSIR Cent Salt & Marine Chem Res Inst, Bhavnagar 364002, Gujarat, India.
Mukherjee, N (corresponding author), CSIR Indian Inst Chem Biol, Canc Biol & Inflammatory Disorder Div, Kolkata 700032, India.
Chattopadhy, S (corresponding author), BITS Pilani, Pilani 403726, Goa, India.
Das, A (corresponding author), Indian Inst Sci Educ & Res Kolkata, Mohanpur 741246, W Bengal, India.
[email protected]; [email protected]; [email protected]
Energy Efficient Wideband Supply Interpolating Transmitter for Millimeter-Wave 5G System
No full textIn 5G transmitters, high efficiency, high linearity, and compatibility with MIMO and beamforming techniques are of utmost importance. Typically, enhancement techniques like supply modulation or load modulation are used when dealing with envelope modulated communication signals, which increasingly have high peak-to-average-power ratios (PAPR). Supply modulation is most favored in handsets. Techniques like "Envelope Tracking (ET)" or "Envelope Elimination and Restoration (EER)" are employed to generate high efficiency over a large power back-off range. These techniques are robust to antenna impedance variations compared to load modulation techniques like Doherty. However, the downside of supply voltage modulation is the need for a dynamic supply modulator. Such supply modulators are very difficult to implement for systems with video bandwidths >20MHz. For modern communication systems like 5G, video bandwidths for both the base stations and handsets are drastically increasing (up to ~1GHz). 5G communication is also going to operate at very high frequencies, commonly known as mm-wave. This degrades the efficiency of the transmitter because of increased losses in the output conductance of the active device and from any power combining network. Furthermore, due to the use of (massive) MIMO/smart-antenna techniques in these 5G base stations, there will also be undesired time-fluctuating antenna impedances due to PA back-coupling through the antenna array, which are extremely difficult to handle in efficiency enhancement techniques based on load modulation. In this thesis, a new type of wideband "supply voltage modulation" has been investigated. The aimed concept uses multiple constant supply voltages rather than a single time variant dynamic voltage supply. Several "parallel" PA devices are connected to different DC supply voltages while their RF output terminals are AC connected. The PA connected to a lower DC supply is used in the low power region, while the PA with a higher DC supply is used in the high power region. This ensures that the DC power consumption is output power dependent. By gradually controlling the amplifier branches through their RF inputs, proper transitions can be made between the different amplifier branches (i.e., from low power to high power region and vice versa)gENESIsNXP STWElectrical Engineering | Microelectronic
What is American in American Literature? Ernest Hemingway: A Case Study
No full textExamines what makes Hemingway a distinctly American author, including his pioneering vision of America, use of the quest myth, and journalistic prose style. Draws on The Sun Also Rises and The Old Man and the Sea
Synergistic effect of Fe/Co-doping and electric field in Niobium Diboride for boosting hydrogen production
No full textA primary concern towards achieving a robust and sustainable water-splitting strategy consists in the development and designing of non-precious hydrogen evolution electrocatalysts capable of operating at relatively high current densities. In the present density functional theory (DFT) based study, we explored and identified α-NbB2-based catalysts consisting of Borophene as graphene-like noble metal-free networks in Niobium-metal based networks, as promising catalysts for the hydrogen-evolution reaction (HER). Our results unveiled that Fe/Co covalent doping in α-NbB2 {001} surface provides high-efficiency HER activity sites, namely, TNb-sites in Nb-terminated Fe/Co-NbB2 {001} surface with the lowest ΔGH∗ Gibbs free energy value of about 0.264/0.278 eV, which further drops to a very optimal value in the range of ΔGH∗ ≤ ± 0.10 eV upon the implementation of an external electric field. Furthermore, it was also revealed that in contrast to the extensively used Pt-based surface catalysts, both α-NbB2 and Fe/Co-NbB2 catalysts can sustain consistently high catalytic activity for HER over a very large hydrogen coverage and thus ensure a large density of effective catalytic free sites.</p
Research Productivity in the Departments of Chemistry and Physics of The University of Burdwan during 1960 – 2000: A Comparative Study.
Get PDFDuring 1960-2000, Chemistry and Physics department of the University of Burdwan, produced 141 awarded Chemistry theses, 979 published Chemistry thesis articles and 67 awarded Physics theses, 610 published Physics thesis articles. To compare the year wise productivity, authorship pattern and collaboration, Co-authorship pattern, Impact of authors, the citation scenario of the outstanding authors and ranked list of journals they have been analysed. The highest number of thesis (30) during 1986-1990 & 1991-1995 and the highest number of thesis articles (283) during 1991-1995 was submitted by the Chemistry Department whereas Physics department submitted highest number of theses (19) and highest number of thesis articles (158) during 1986-1990. The highest degree of collaboration is found in Physics Department (0.73) followed by Chemistry Department (0.70). Considering the name of the first authors only, the most prolific author were B.N Biswas (Physics) who topped the list with 108 papers followed by G.C Bhar (Physics) with 94 publications, A.K Das (Chemistry). The most credited author (considering fractional credit of authorship at any authorship position)was A.K Das (Chemistry Department) who topped the list with 84.7502 points, followed by B.N Biswas (Physics Department). The author with highest impact (according to 1st author) was G.C Bhar (Physics Department) who topped the list with 113.87 points, followed by A.K Das (Chemistry Department)with 45.82 points. The author with highest impact (considering all authors at any authorship position with shared credit) was G.C Bhar (Physics Department) who topped the list with 75.5825 points, followed by K Bhattacharya (Chemistry Department) with 36.6250 points. B.K Ghosh (Chemistry Department) received highest number of citations (662), whereas G.C Bhar (Physics Department) received 292 citations during this period. The leading journals preferred by the researchers of Chemistry departments are Ind Jl Chem with 185 papers and Ind Jl Pure Appl Phy with 47 papers by the researchers of Physics department. Taking all the papers of the two Departments together 692(43.54%) articles are published in Indian journals and 897 (56.46%) papers are published in foreign journals
Comparative Performance Study and Analysis on Different Edge based Image Segmentation Techniques of Thermal Images
Get PDFIn this work, authors have been tried to analyse the edge-based approach for thermal image segmentation. Here, author?s have used different thermal images for the edge based analysis of image segmentation. Author?s have given studies regarding different edge operators like Prewitt, Sobel, LoG, and Canny edge detection operators for segmentation purposes and analyze their performance. This paper compares each of these operators by the manner of checking Peak signal to Noise Ratio (PSNR) and Mean Squared Error (MSE) of resultant image. It evaluates the performance of each algorithm using image quality analysis. This paper presents a comparative analysis of different edge based thermal image segmentation techniques
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