Paramita Ray

Polymer Grafting and Crosslinking

Introduction (Amit Bhattacharya and Paramita Ray). 2. Basic Features and Techniques (Amit Bhattacharya and Paramita Ray). 3. Mechanism and Kinetics (Chris Fellows). 4. Analytical Evidences (Amit Bhattacharya and Paramita Ray). 5. Broader Spectrum: Examples (Inderjeet Kaur and Paramita Ray). 6. In Biomedical Arena (Gauri Misra, Eun Gil, and Tao Lowe). 7. Application in Textiles (Mohammed Rahman). 8. In Automobiles (James Rawlin and Jeremy Swanson). 9. In Cable Technology (Achintya Sen). 10. Separation and purification (Mohamed Nasef). 11. Coatings, Adhesives, and Laminates (James Rawlin and Sharath K. Mendon). 12. In Commodity Plastics (James Rawlin and James Whittermore IV) Future Directions (Amit Bhattacharya).

Polyvinyl alcohol as the barrier layer in thin film composite nanofiltration membranes: preparation, characterization, and performance evaluation.

The present paper describes the preparation, characterization, and performance evaluation of thin film composite (TFC) nanofiltration (NF) membranes having porous polysulfone as base support and polyvinyl alcohol (PVA, degree of hydrolysis 86-87% and molecular weight 125,000) as the final barrier layer. Maleic acid (MA) was used as the cross-linker of PVA. The membranes were characterized by their molecular weight cutoff, FTIR, SEM, and contact angle. The effects of variation of different parameters like concentration of polysulfone, polyvinyl alcohol, maleic acid, and cure time on the membrane performance (flux and rejection of inorganic salts) were studied and the optimum membrane composition was evaluated. From the analysis of flux and rejection data it may be concluded that membranes prepared from 17%PSF, 1%PVA, with MA solution concentration of 0.2% (w/w) cured at a temperature of 125+/-2 degrees C for 30 min give the optimum balance of flux and rejection (R). Such membranes show differential rejection among the sulfate and chloride salts. For membranes prepared under optimum conditions the average rejections of NaCl and MgSO4 are 22.8% and 83.8%, respectively; i.e., on an average 60% difference exists between the rejection of MgSO4 and NaCl. The overall trend of rejection by such membranes is R(Na2SO4) > R(MgSO4) > R(NaCl) > R(CaCl2) approximately = R(MgCl2) (R = rejection). The average MWCO of these membranes varies between 250 and 350 Da.

Separation of inorganic and organic acids from glyoxal by electrodialysis

Abstract The electrodialysis (ED) processemploying ion-exchange membranes has been used mainly for the desalination of brackish water and concentration of seawater. Of late ED has become a unique process for the separation of ionic and non-ionic substances from chemical mixtures. In such manufacturing processes, glyoxal is produced by the oxidation of acetaldehyde with nitric acid. After the reaction, the product contains nitric acid, acetic acid, glycolic acid, etc., which are to be separated from the mixture. Attempts were made to make use of ED to separate electrolytes from non-electrolytes and to separate nitric acid and weak organic acids from glyoxal. The experimental results obtained from the separation of nitric acid, organic acids and glyoxal under different experimental conditions are presented and discussed.

Nature of sexual dysfunctions in major depressive disorder and its impact on quality of life.

Background: Adequate sexual expression is an essential part of many human relationships, and may enhance quality of life and provide a sense of physical, psychological, and social well-being. Epidemiological and clinical studies show that depression is associated with impairments of sexual function and satisfaction, even in untreated patients. Most antidepressant drugs have adverse effects on sexual function, but accurate identification of the incidence of treatment-emergent dysfunction has proved troublesome. However, few investigators have reported the base rate for disturbances in sexual desire, arousal, and orgasm or ejaculation in patients with major depressive disorder (MDD) prior to antidepressant treatment. The purpose of this study is to define the frequency of sexual dysfunction (SD) in 60 patients with MDD and examine the relationship between SD and quality of life enjoyment and satisfaction variables. Materials and Methods: A consecutive series of 24 male and 36 female MDD patients diagnosed by SCID-DSM IV assessment completed a series of psychometric measures including a Sexual Function Questionnaire—Arizona Sexual Experience Scale (ASEX) which asked about change in sexual interest and function as well as quality of life of life enjoyment using QLESQ-SF. Results: Over 33.33% of men and 42% of women reported decreased sexual interest. Reduced levels of arousal were more common in both men and women (8-22%) than ejaculatory or orgasm difficulties (11–16%). In women, SDs were more than males. Quality of life was more impaired in sample with SDs than those without dysfunction showing significant impact of SD on quality of life. Limitation and Conclusion: Although limited by a relatively small sample of drug-free patients with MDD, and by the absence of a non-depressed comparison sample, these results emphasize the importance of factors beyond specific drug effects in the assessment of SD in drug naive-depressed patients.