The virial equation of state based on critical constants

Results obtained from the Epstein equation of state15 i.e. equation (8), which is theoretically valid up to the critical density, are compared with the experimental values of the compressibility factor. The calculated values of compressibility factor or ethylene, ethane, propane, and n-butane were obtained using two methods of evaluation for the second and third virial coefficients. In addition, using these two methods and excluding fourth, fifth, and sixth virials in the Epstein equation of state, compressibility factors were calculated for all the four compounds to test the effect of higher virial terms. In the proposed method-(A) and method-(C), the force constants were calculated from critical properties while, in methods-(B) and (D), force constants which are based on experimental p-v-t data, were directly taken from the literature. For methods-(A) and (B), Epstein equation of state i.e. equation (8), was used. While, for methods-(C) and (D), fourth, fifth, and sixth virials were neglected in the Epstein equation of state, which reduced to equation (11). The proposed method-(A) which only requires the information on critical properties, gave results within the acceptable range of accuracy for all the four compounds. The other methods gave poor results. Epstein has suggested that his equation is valid only for non-polar and spherical molecules. It is, however, shown in this work that his equation is also valid for linear molecules, if the force constants from critical properties are used in the evaluation of second and third virial coefficients. The proposed method-(A) requires only three parameters i.e. critical constants, and is comparable in accuracy to the Beattie-Bridgeman equation

The generalized virial equation of state

A generalized three parameter virial equation of state has been developed and tested for seven pure gases having different molecular characteristics. The equation has also been tested for more than thirteen binary gas mixtures using three different mixture rules. The final equation is as follows: Z = 1 + B(T)/V + C(T)/V2 + D(T)/V3 + E(T)/V4 + VF(T)/eaV + VG(T)/ebV The expressions for E(T), F(T), and G(T) along the critical isotherm were derived in terms of critical properties and two constants, a and b which appear in the sixth and seventh terms in the above equation from the conditions that the first and second derivatives of pressure with respect to volume are zero at the critical point. The two unresolved parameters, i.e. a and b, were established from the experimental P-V-T data along the critical isotherms of pure gases, i.e. nitrogen, carbon dioxide, propane, carbon monoxide etc. A direct minimum seeking method which operates on an error function constructed below, Er = Σni=1 (Zi, obs - Zi, cal.)2/n2 was used. By minimizing the function, the best value of the parameters i.e. a and b, was obtained. The second, third, and fourth virial coefficients were calculated from the Gyorog and Obert Tables (37), using the Lennard-Jones force constants obtained from the critical properties by means of generalized relationships. The calculated compressibility factors for all of the systems were compared with the Gyorog-Obert, Redlich-Kwong, and Generalized BWR equations. The absolute average and maximum deviations from the experimental values were computed for all the systems considered in this work. Expressions for the fugacity of components in gaseous mixtures were derived for the Joffe-Zudkevitch mixture rule. The fugacities of components in:gas mixtures and the enthalpy departures from ideal gas values were calculated for three binary gas mixtures using the Joffe-Zudkevitch and the Pitzer-Hultgren mixture rules. The equation presented in this work gave excellent results when compared to the standard Redlich-Kwong, the generalized BWR, and the Gyorog-Obert equations of state, The equation developed in this work gave less than 1.5 percent average deviation for compressibility factors of pure gases and below 3 percent for compressibility factors of binary mixtures up to 1.8 times the critical density. The results for other thermodynamic properties are also superior to those obtained with the Redlich-Kwong and Gyorog-Obert equations.It is noteworthy that the range of applicability in the gaseous region of the three-parameter generalized virial equation developed in this study is the same as that of the eight constant Benedict-Webb-Rubin equation, i.e. up to 1.8 times the critical density

ISOLATION AND CHARACTERIZATION OF SHATAVARIN IV FROM ROOT OF ASPARAGUS RACEMOSUS WILLD

Objective: To develop a method for the isolation of the steroidal saponin Shatavarin IV from the root of Asparagus racemosus Willd.Methods: Powder of Asparagus racemosus dried roots were defatted with hexane and extracted with methanol. The methanolic extract was used for isolation of pure compound by column chromatography. Isolated compound was identified by melting point analysis, IR and Mass spectroscopic analysis. Purity was checked by High-performance thin layer chromatography (HPTLC).Results: The highest yield of Shatavarin IV was obtained 401.1 mg from 250 g crude powder and highest purity was achieved 66% of lower atmospheric temperature (17-22 °C).Conclusion: Shatavarin IV isolation using column chromatography was affected with the change in atmospheric temperature. Maximum yield was obtained at the lower temperature i.e. 17-22 °C, whereas at higher temperature the Shatavarin IV showed degradation in purity and yield.Â

Stevia (Meethi Patti) as an alternative form of sugar

Stevia rebaudiana (Bertoni) is a herb. Stevioside, non-caloric sweetener present in the leaves of Stevia are non-nutritive, non-toxic, high-potency sweeteners and being 300 times sweeter than sucrose may be alternate for sucrose as well as other synthetic sweeteners. This review summarizes history of Stevia, nutritional composition of Stevia, cultivation, industrial overview and biological applications. Keywords: Stevia rebaudiana, Stevioside, Sweetene

FORMULATION AND EVALUATION OF GEL CONTAING AMLEXANOX FOR MOUTH ULCER

Abstract: Objective: To formulate and evaluate mouth gel of amlexanox using an admixture of gelling agent i.e. carbopol p940 and penetration enhancer i.e. propylene glycol. Experimental work: Gel containing amlexanox was prepared by taking carbopol p934 and propylene glycol as penetration enhancer in different ratio. The concentrations of carbopol p934 and propylene glycol were optimized using 3 2 full factorial designs. The parameters determined were pH, drug content, viscosity, spradability, extrudability, in vitro drug release. Results: The pH values of gels were between 6.0 to 7.0. Drug content values were between 89% to 98%. Drug release was dependent on the concentration of carbopol and concentration of propylene glycol. The in vitro drug release time was 3 hr. Drug release from the gels increased with increase in the concentration of propylene glycol up to 10%. However, drug release decreased with further increase in the concentration of the propylene glycol to 20%. Conclusion: Formulation F6 with concentration of carbopol (1%) and concentration of propylene glycol (7%) showing maximum drug release upto 3 hr. was selected as the optimized formulatio

Virilizing ovarian steroid cell tumor in a 40 year old South Indian female: a case report

Virilism is the masculinization and enhancement of male secondary sexual characteristics in females. The etiology is usually of adrenal or ovarian origin. Here we report a case of virilizing Leydig cell type, steroid cell tumor of the left ovary, in a 40 year old female who presented with clinical signs and symptoms of virilization: deepening of voice, hirsutism (Ferriman-Gallwey score 26), clitoromegaly, and androgenic alopecia. On further evaluation, laboratory investigations revealed hyperandrogenism in the male range. Basal testosterone values were elevated. Folicle Stimulating Hormone and Luteinising Hormone levels were within normal limits. Dexamethasone suppression test did not alter cortisol or testosterone levels. An ovarian mass was confirmed radiologically. Following a total abdominal hysterectomy with bilateral salpingoophorectomy, histopathological studies confirmed a left sided steroid-cell ovarian tumor, Leydig cell type (stage T1N0M0), which proved to the etiology of virilization in this patient. Post-operatively her serum testosterone levels declined with near-complete reversal of symptoms over time

Study on character association and path analysis in little millet (Panicum sumatrense L.)

Little millet (Panicum sumatrense L.) is one of the neglected crops which is becoming popular as nutri-cereal. Development of high yielding stable cultivars may offer better economic return from this crop. Assessment of interrelationship among important economic traits helps to identify major yield component traits which could be selected for overall yield improvement hence development of superior genotypes. In this context, 50 genotypes of little millet were evaluated during kharif 2021, to identify important yield component traits through correlation and path analysis of 16 quantitative traits. Estimates of genotypic correlation coefficients were found to be higher than the estimates of phenotypic correlation coefficients, indicating that association were majorly under genetic control. It was revealed that direct selection based on fodder yield per plant, plant height and 1000 seed weight may help in augmenting grain yield in the experimental material, whereas, harvest index came out as the most important character for indirect selection

Sex‐Specific Associations of Oral Anticoagulant Use and Cardiovascular Outcomes in Patients With Atrial Fibrillation

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139084/1/jah32481-sup-0001-TableS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139084/2/jah32481.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139084/3/jah32481_am.pd

Unilateral hemothorax in a 46 year old South Indian male due to a giant arteriovenous hemodialysis fistula: a case report

In a patient undergoing regular hemodialysis through an arteriovenous fistula access, pleural effusion is a known long term complication. However, a unilateral hemothorax is relatively uncommon. Here we report a 46 year old male, end-stage renal disease patient, on maintenance hemodialysis, who presented with a giant brachiocephalic AV fistula in his left arm and progressive breathlessness. Radiological imaging revealed a left sided pleural effusion. Ultrasound guided aspiration revealed a hemorrhagic pleural fluid. A Doppler study of the fistula revealed a high velocity blood flow through the fistula, thereby establishing the cause of the unilateral hemothorax. Ligation of the fistula resulted in complete resolution of the hemothorax. The other possible causes for hemothorax in a dialysis patient are also discussed in this case report