Study of Dynamics of Allyl Chloride-2-Butanone Binary System Using Time Domain Reflectometry

Sudake, Y.S.,Kamble, S.P.,Patil, S.S.,Khirade, P.W.,Mehrotra, S.C. Korean Chemical Society 2012 대한화학회지 Vol.56 No.1

Complex permittivity spectra of Allyl Chloride (AC), 2-Butanone (2-BU) and their binary mixtures over the entire range of concentration were obtained using the Time Domain Reflectometry (TDR) technique in microwave frequency range at various temperatures. Static dielectric constant and relaxation time are obtained from complex permittivity spectra. Density ($\rho$) and refractive index ($n_D$) are also measured. These parameters are used to determine excess dielectric constant, excess inverse relaxation time, excess molar volume, excess molar refraction, polarity, Bruggeman factor and thermodynamic parameters viz. enthalpy of activation and entropy of activation. The values of static dielectric constant and relaxation time increases while density and refractive index decreases with the percentage of 2-Butanone in Allyl Chloride increases. Excess parameters were fitted to a Redlich-Kister equation.

Interaction of Cyclohexane-Methyl Acetate Binary System through Dielectric Properties at Different Temperatures

Kamble, Siddharth P.,Sudake, Y.S.,Patil, S.S.,Khirade, P.W.,Mehrotra, S.C. Korean Chemical Society 2011 대한화학회지 Vol.55 No.3

The present paper reports the study of binary mixtures and their properties over the entire range of composition at temperatures 288, 298, 308 and 318 K. Excess dielectric constant, excess molar volume, excess refractive index, molar refraction and excess molar refraction at different temperatures have been computed from the experimentally measured values of the aforesaid parameters and fitted to the Redlich-Kister equation. Excess dielectric constant, excess molar volume excess molar polarizations are negative whereas excess refractive indices are positive over entire mole fraction of methyl acetate for all temperatures. The results are discussed in light of intermolecular interactions occurring in the binary mixture. Estimated coefficients of the Redlich-Kister polynomials and the standard error along the coefficients are also reported. 본 논문은288, 298, 308, 318 K에서 구성 요소의 전체 영역에서 이성분 혼합물과 그 특징을 발표하였다. 각각의 다른 온도에서 초과유전상수, 초과 몰 부피, 초과 굴절률, 몰 굴절, 초과 몰 굴절은 실험적으로 측정된 이전의 파라미터 값으로부터 계산되었고 Redlich-Kister 식으로 확인했다. 초과 유전상수, 초과 몰 부피, 초과 몰 편광은 음수인 반면에 초과 굴절률은 모든 온도에 대해 메틸 아세테이드의 전체 몰 분율에서 양수이다. 본 결과는 이성분 혼합물에서 발생하는 분자 사이의 상호작용을 고려하여 논의 되었다. Redlich-Kister 다항식의 예측된 계수와 계수에 따른 표준오차 또한 보고되었다.

Pharmacognostical Evaluation of Leucas aspera Link.

Vartika Rai,Manisha Agarwal,A.K. Agnihotri,S. Khatoon,A.K.S. Rawat,S. Mehrotra 한국생약학회 2005 Natural Product Sciences Vol.11 No.2

Leucas aspera Link. (Lamiaceae) is an important medicinal plant in indigenous systems of medicinecomunities find diverse medicinal properties. It is used as antipyretic, stimulant, expectorant and diaphoreticdrug. The present communication deals with the detailed pharmacognostical evaluation of whole plant of L.aspera collected from five different geographical zones of the country-Uttar Pradesh, Orissa, Karnataka, WestBengal and Gujarat. The botanical characters and TLC fingerprint profile of all the samples were quite similar butsome variations were observed in physicochemical parameters. However, some microscopical characters and TLCprofile can be used as diagnostic characters for identification of , for example amphistomachic leavesand two types of trichomes-abundant, non glandular, uniseriate, 1-3 celled and few glandular, 2-5 celled stalk withrounded tip. Presence of some components at Rfs-0.56, 0.65 and 0.76 under UV 366 and at Rfs-0.31, 0.43, 0.60,0.76 and 0.82 under visible light after derivetization in TLC profile may also be used as diagnostic character.

Dielectric Relaxation in Ethylene Glycol - Dimethyl Sulfoxide Mixtures as a Function of Composition and Temperature

Undre, P.B.,Khirade, P.W.,Rajenimbalkar, V.S.,Helambe, S.N.,Mehrotra, S.C. Korean Chemical Society 2012 대한화학회지 Vol.56 No.4

Using time domain reflectometry, the complex dielectric spectra between 10 MHz to 20 GHz has been measured in the whole composition range at 10, 20, 30 and $40^{\circ}C$ for the binary mixtures of ethylene glycol and dimethyl sulfoxide. For all the mixtures, only one dielectric loss peak was observed in this frequency range. The relaxation in these mixtures can be described by a single relaxation time using the Debye model. A systematic variation is observed in dielectric constant (${\varepsilon}_0$) and relaxation time (${\tau}$). The excess permittivity (${\varepsilon}^E$), excess inverse relaxation time $(1/{\tau})^E$, Kirkwood correlation factor (g) and thermodynamic parameters viz. enthalpy of activation (${\Delta}H$) and Gibbs free energy of activation (${\Delta}G$) have been determined, to confirm the formation of hydrogen bonded homogeneous and heterogeneous cooperative domains, the dynamics of solute - solute interaction and the hindrance to molecular rotation in the hydrogen bonded glass forming ethylene glycol - dimethyl sulphoxide system.

Preparation and Charecterization of Bromofullerenes in New Stoichiometry

Mehrotra, Reema,Lal, Darshan,Tripathi, V.S.,Mathur, G.N. Korean Carbon Society 2003 Carbon Letters Vol.4 No.4

It is well established that halogenated fullerene derivatives act as synthetic intermediates for further substitution via replacement with nucleophlies. In the present work, systematic studies were carried out on the synthesis of bromofullerenes under different experimental conditions. The effect of reaction time on the product formed was observed. We observed the formation of new compound of bromofullerenes in a different stoichiometric ratio i.e., $C_{60}Br_{14}$; in addition to previous reported bromofullerenes in the stoichiometric ratio of $C_{60}Br_6$, $C_{60}Br_8$, and $C_{60}Br_{24}$. The new derivative of bromofullerene was isolated and well characterized by various analytical techniques like FT-IR, TGA, DSC, and elemental analysis. In this paper, detail of the synthesis and characterization of the bromofullerene prepared are described. The yields obtained were better than those reported previously.

Seasonal Variation Studies and Pharmacognostic Evaluation ofAlstonia scholaris R.Br. Bark

A. S. Upadhye,Sayyada Khatoon,Shanta Mehrotra 한국생약학회 2006 Natural Product Sciences Vol.12 No.4

Pharmacognostic Evaluation of the Flower of Alcea rosea L.

Shanta Mehrotra,A. K. S. Rawat,Usha Shome 한국생약학회 1999 Natural Product Sciences Vol.5 No.1

The flowers of Alcea roses L., Malvaceae, sold in the Indian market under the trade name `Gulkhairo`, are well known for their expectorant, cooling and diuretic properties and used in many indigenous cough mixtures in India. The present paper deals with the detailed pharmacognosy of the floral parts including morphological, anatomical, phytochemical and fluorescence characters. Some of the diagnostic features of the drug are : pedicel characterized by multicellular appendages, stellate hairs, rosette crystals of Ca-oxalate. starch sheath and large sized mucilage canals; sepals having distinctive multicellular appendages arranged in a semilunar fashion present adaxialty at their base; monadelphous stamens, pollen grains pentaporate provided with dimorphic spines; placentation axile, ovules campylotropous; dark green fluorescence of the powder with nitrocellulose in amyl acetate and yellow fluorescence of trichomes under Fluorescence microscope.

Standardization and Quality Evaluation of Banafsha

Shanta Mehrotra,A. K. S. Rawat,Usha Shome 한국생약학회 1998 Natural Product Sciences Vol.4 No.1

`Banafsha` is an important herbal drug of indigenous systems of medicine. Flowers of Viola odorata L. (Violaceae) are considered to constitute the genuine drug `Banafsha`. However, due to limited distribution of this plant, another species of Viola, i.e. V. pilosa having almost similar medicinal properties, is mostly used under this vernacular instead. Ethnobotanically also different species of Viola i.e. V. odorata, V. pilosa and V. betonicifolia are used for various ailments at different places in our country. In the present study two species of Viola, namely V. pilosa and V. betonicifolia along with the commercial samples of `Banafsha` were studied and authenticated. It was observed that the market samples procured from Dehradun, Mumbai, Lucknow, Palampur, Ramnagar and Ranikhet showed close resemblance with Viola pilosa in having similar morphological characters like uniseriate hairs on the ovary, geniculate and clavate style, truncate stigma and almost similar TLC profiles. On the other hand the Almora sample was identified as Viola betonicifolia by the presence of large purple flowers, clavate style and convex stigma forming hump like structure. However, the market sample procured from Pathankot was found to be a mixture of two species of Viola namely, V. pilosa and V. odorata having dominance of the former species.

Preparation and Charecterization of Bromofullerenes in New Stoichiometry

Reema Mehrotra,Darshan Lal,V.S. Tripathi,G.N. Mathur 한국탄소학회 2003 Carbon Letters Vol.4 No.4

It is well established that halogenated fullerene derivatives act as synthetic intermediates for further substitution viareplacement with nucleophlies. In the present work, systematic studies were carried out on the synthesis of bromofullerenesunder different experimental conditions. The effect of reaction time on the product formed was observed. We observed theformation of new compound of bromofullerenes in a different stoichiometric ratio i.e., C60Br14; in addition to previousreported bromofullerenes in the stoichiometric ratio of C60Br6, C60Br8, and C60Br24. The new derivative of bromofullerene wasisolated and well characterized by various analytical techniques like FT-IR, TGA, DSC, and elemental analysis. In this paper,detail of the synthesis and characterization of the bromofullerene prepared are described. The yields obtained were better thanthose reported previously.

시간분해기법을 이용한 디메틸 술폭사이드와 디메틸 포름아미드-아닐린용액에서 온도의존 유전이완에 관한 연구

Chaudhari, Ajay,Patil, C.S.,Shankarwar, A.G.,Arbad, B.R.,Mehrotra, S.C. 대한화학회 2001 대한화학회지 Vol.45 No.3

aniline-dimethylsulphoxide(DMSO)와 aniline-dimethylformamide(DMF) 계에서 dielectric relaxation 에 관한 연구를 10MHz-10GHz 진동수 영역에서 여러 가지 다른 온도 그리고 농도에서 Time Domain Reflectometry(TDR) 방법을 이용하여 수행하였다. dielectric parameter를 정적유전율, 이완시간, Kirkwood 상관계수, 잉여유전율, 잉여 역이완시간, 그리고 열역학 parameter들의 함수로 얻었다. 검정방법으로 최소자승법을 이용하였다. dielectric parameter 들이 온도와 농도에 대해 체계적으로 변하는 것을 볼 수 있었다. The dielectric relaxation study for aniline-dimethylsulphoxide (DMSO) and aniline-dim.ethylformamide(DMF) has been carried out using the Time domain reflectometry (TDR) technique, at different temperature and concentrations, in the frequency range of 10 MHz to 10 GHz. The dielectric parameters viz. static permittivity, relaxation time, the Kirkwood correlation factor, excess permittivity, excess inverse relaxation time and thermodynamic parameters have been obtained. The calibration method based on least squares fit method has been used. The dielectric parameters show systematic change with temperature and concentrations.