OALib Journal期刊

ISSN: 2333-9721



匹配条件: “Atram Sandeep” ,找到相关结果约1267条。
Formulation and evaluation of immediate release tablet using response surface methodology
Atram Sandeep
Asian Journal of Pharmaceutics , 2011,
Abstract: The purpose of the present work was to develop an optimized immediate release tablet for hypertensive patients using amlodipine besylate as a model drug candidate by optimization technique to produce the intended benefits. A 3 2 factorial design was employed in formulating immediate release tablet. The independent variables selected were superdisintegrants such as sodium starch glycolate and in addition to that, effect of microcrystalline cellulose was studied. The dependent variables considered for study was DT and DP 60 . The tablets prepared were evaluated for thickness, uniformity of weight, hardness, friability, wetting time, in vitro disintegration time, and in vitro drug release study. The response surface plots differentiate the results between the independent and dependent variables. Apart from fulfilling all official and other specifications, the tablets exhibited higher rate of release.
Influence of Supernova SN Ia Rate and the Early Star Formation Rate on the Galactic Chemical Evolution  [PDF]
Sandeep Sahijpal
International Journal of Astronomy and Astrophysics (IJAA) , 2013, DOI: 10.4236/ijaa.2013.33038

Based on the recently developed numerical approach to understand the formation and the chemical evolution of the milky-way galaxy in the solar neighborhood we study the influence of the supernova type SN Ia rates on the galactic chemical evolution. Supernova SN Ia plays an important role in producing the iron inventory of the galaxy. We also study the dependence of the chemical evolution on the star formation rate prevailing during the initial one billion years of the evolution of the galaxy. This era marks the formation of the galactic halo and the thick disk. A comparison of the elemental abundance distributions of the dwarf stars in the solar neighborhood is made among the various models simulated in the present work. In order to explain the majority of the observed elemental evolutionary trends, specifically those related with the galactic evolution of iron and oxygen, it would be essential to incorporate a major component of prompt SN Ia to the galactic evolution. The prompt SN Ia would produce significant fraction of SN Ia within the initial ~100 million years from the time of star formation. The essential requirement of prompt SN Ia would result in a significant enhancement of SN Ia rates during the earliest epoch of the galaxy. The elemental evolutionary trends also favor an enhancement in the star formation rate during the initial one billion years of the galaxy at least by a factor of three compared to the trend prevailing during the latter evolutionary time of the galaxy.

Galaxy Formation and Chemical Evolution  [PDF]
Sandeep Sahijpal
International Journal of Astronomy and Astrophysics (IJAA) , 2014, DOI: 10.4236/ijaa.2014.43045

The manner the galaxy accretes matter, along with the star formation rates at different epochs, influences the evolution of the stable isotopic inventories of the galaxy. A detailed analysis is presented here to study the dependence of the galactic chemical evolution on the accretion scenario of the galaxy along with the star formation rate during the early accretionary phase of the galactic thick disk and thin disk. Our results indicate that a rapid early accretion of the galaxy during the formation of the galactic thick disk along with an enhanced star formation rate in the early stages of the galaxy accretion could explain the majority of the galactic chemical evolution trends of the major elements. Further, we corroborate the recent suggestions regarding the formation of a massive galactic thick disk rather than the earlier assumed low mass thick disk.

Isolated Anterior Pneumomediastinum as a Complication of Oesophageal Foreign Body
Kundan S Gosavi,Surbhi D Mundada,Sukriti Atram,Aniruddh Nirkhi
Indian Anaesthetists' Forum , 2011,
Abstract: A two years old child developed pneumomediastinum in the postoperative period after foreign body removel from oesophagus. He was managed conservatively without a thoracostomy tube.
A floating pulsatile drug delivery system based on hollow calcium pectinate beads
Somani V,Shahi S,Udavant Y,Atram S
Asian Journal of Pharmaceutics , 2009,
Abstract: The objective of the present work is to envisage and develop hollow calcium pectinate beads for floating pulsatile release of aceclofenac intended for chronopharmacotherapy. Floating pulsatile concept was applied to increase the gastric residence of the dosage form having lag phase followed by a burst release. The method used for the development of the beads was a simple process of acid-base reaction during ionotropic cross linking. The floating beads obtained were porous, hollow with a bulk density < 1 and had an F t50 of 14-24h. The floating beads showed a two-phase release pattern with initial lag phase during floating in an acidic medium followed by rapid pulse in phosphate buffer. The approach indicates the use of hollow calcium pectinate microparticles as a promising floating pulsatile drug delivery system for site- and time-specific release of drug acting as per chronotherapy of disease.
Nonlinear Blind Equalizers: NCMA and NMCMA  [PDF]
Donglin Wang, Sandeep Chandana
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2010, DOI: 10.4236/ijcns.2010.36070
Abstract: This paper proposes two nonlinear blind equalizers: the nonlinear constant modulus algorithm (NCMA) and the nonlinear modified constant modulus algorithm (NCMA) by applying a nonlinear transfer function (NTF) into constant modulus algorithm (CMA) and modified constant modulus algorithm (MCMA), respectively. The effect of the NTF on CMA and MCMA is theoretically analyzed, which implies that the NTF can make their decision regions much sharper so that the proposed two nonlinear blind equalizers are more robust against the convergency error compared to their linear counterparts. The embedded single layer in NCMA and NMCMA simultaneously guarantees a comparably speedy convergency. On 16-quadrature amplitude modulation (QAM) symbols, computer simulations show that NCMA achieves an 8dB lower convergency mean square error (MSE) than CMA, and NMCMA achieves a 15dB lower convergency MSE than MCMA.
Dynamic Identity Based Authentication Protocol for Two-Server Architecture  [PDF]
Sandeep K. Sood
Journal of Information Security (JIS) , 2012, DOI: 10.4236/jis.2012.34040
Abstract: Most of the password based authentication protocols make use of the single authentication server for user's authentication. User's verifier information stored on the single server is a main point of susceptibility and remains an attractive target for the attacker. On the other hand, multi-server architecture based authentication protocols make it difficult for the attacker to find out any significant authentication information related to the legitimate users. In 2009, Liao and Wang proposed a dynamic identity based remote user authentication protocol for multi-server environment. However, we found that Liao and Wang's protocol is susceptible to malicious server attack and malicious user attack. This paper presents a novel dynamic identity based authentication protocol for multi-server architecture using smart cards that resolves the aforementioned flaws, while keeping the merits of Liao and Wang's protocol. It uses two-server paradigm by imposing different levels of trust upon the two servers and the user's verifier information is distributed between these two servers known as the service provider server and the control server. The proposed protocol is practical and computational efficient because only nonce, one-way hash function and XOR operations are used in its implementation. It provides a secure method to change the user's password without the server's help. In e-commerce, the number of servers providing the services to the user is usually more than one and hence secure authentication protocols for multi-server environment are required.
On Secure Digital Image Watermarking Techniques  [PDF]
Manjit Thapa, Sandeep Kumar Sood
Journal of Information Security (JIS) , 2011, DOI: 10.4236/jis.2011.24017
Abstract: Digital watermarking is used to hide the information inside a signal, which can not be easily extracted by the third party. Its widely used application is copyright protection of digital information. It is different from the encryption in the sense that it allows the user to access, view and interpret the signal but protect the ownership of the content. One of the current research areas is to protect digital watermark inside the information so that ownership of the information cannot be claimed by third party. With a lot of information available on various search engines, to protect the ownership of information is a crucial area of research. In latest years, several digital watermarking techniques are presented based on discrete cosine transform (DCT), discrete wavelets transform (DWT) and discrete fourier transforms (DFT). In this paper, we propose an algorithm for digital image watermarking technique based on singular value decomposition; both of the L and U components are explored for watermarking algorithm. This technique refers to the watermark embedding algorithm and watermark extracting algorithm. The experimental results prove that the quality of the watermarked image is excellent and there is strong resistant against many geometrical attacks.
Genetic Algorithm for the Design of Optimal IIR Digital Filters  [PDF]
Ranjit Singh, Sandeep K. Arya
Journal of Signal and Information Processing (JSIP) , 2012, DOI: 10.4236/jsip.2012.33038
Abstract: This paper presents the design of Optimal Infinite-Impulse Response (IIR) digital filters using Genetic Algorithm (GA). IIR filter is essentially a digital filter with Recursive responses. Since the error surface of digital IIR filters is generally nonlinear and multimodal, global optimization techniques are required in order to avoid local minima. This paper presents heuristic way for the designing IIR filters. GA is a powerful global optimization algorithm introduced in combinatorial optimization problems. The paper finds the optimum Coefficients of IIR digital filter through GA. Design of Lowpass and High pass IIR digital filter is proposed to provide estimate of transition band. It is found that the calculated values are more optimal than fda tool available for the design of filter in MATLAB. The simulation result of the employed examples shows an improvement on transition band and mean-square-error (MSE). The position of pole-zero is also presented to describe stability and results are compared with Simulated Annealing (SA) method.
SYNTHESIS OF N-{[7-METHOXY-2-(4-METHOXYPHENYL)-1-BENZOFURAN -5-YL]METHYL}CYCLOPENTANAMINE BY REDUCTIVE AMINATION Synthese von N-{[7-METHOXY-2-(4-methoxyphenyl)-1-BENZOFURAN -5-yl] methyl} cyclopentanamine durch reduktive Aminierung
Bapu R Thorat, Dyaneshwar Shelke, Ramdas G Atram and Ramesh S Yamgar
Heterocyclic Letters , 2013,
Abstract: Vanillin (1) undergoes sequence of reaction forming phosphonium salt through dimethyaminomethyl derivative (Mannich reaction). The synthesis of phosphonium salt can be achieved by sequence of three steps. A solution of amino compound in acetic anhydride was refluxed for 24 hrs to give crude diacetate which is purified and reacted with HCl to give chloromethyl derivative. It is reacted with triphenylphosphine in dry benzene under reflux condition. The phosphonium salt undergoes condensation with 4-methoxybenzoyl chloride by refluxing in toluene in presence of triethylamine (Wittig reaction). The resulting 7-methoxy-2-[4- (methoxy)phenyl)-l-benzofuran-5-carboxaldehyde (4) was subjected to reductive amination and the final product N-{[7-methoxy-2-(4-methoxyphenyl)-1-benzofuran-5- yl]methyl}cyclopentanamine (5) was purified by column chromatography and characterized by NMR and Mass spectroscopy.

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