Synthesis and Characterization of Silica from Ragi Husk Ash (Finger Millet) by a Sol-gel Method

Silica aerogel, a mesoporous material, was prepared from ragi husk ash by sol–gel method and dried under atmospheric pressure. In this method, ragi  husk ash, which is rich in silica, was extracted with sodium hydroxide solution to produce a sodium silicate solution. This solution was neutralized with acid to form a silica aerogel. The aged gel was washed carefully by de ionized water and ethanol and finally dried under atmospheric air. A temperature of 7000C was found to be optimum ashing temperature with maximum amorphous silica content. From a morphological analysis obtained by SEM and diffraction patterns (XRD), a longitudinal fibrous and amorphous structure was observed for Ragi Husk. FTIR characterization indicated the presence of silanol and siloxane groups. Thermo gravimetric was used to characterize burning behaviour and also to determine the activation energies. This economic technology, as applied to waste material, also provides many benefits to the local agro-industry. Keywords: Ragi husk Ash, Sol- gel method, Amorphous silica, Aeroge

Preparation and Characterization of Silica Material from Rice Husk Ash – An Economically Viable Method

Rice husk is a form of agricultural biomass that provides an abundant silicon source. Rice husks are widely burnt in agricultural fields in India because it is difficult to find other uses for them. Farmers burn rice hulls usually under incomplete combustion conditions to avoid accidental fires. The objective of this study was to develop a new method of amorphous silica was prepared from rice husk ash by sol - gel method. Initially received from Rice husk ash was calcined at 4000C, 5000C, 6000C and 7000C for 5 hrs to remove the volatiles in the sample and determine the amorphous structure of SiO2. Next, the thermally treated RHA was mixed with alkali solution to produce sodium silicate solution and precipitated silica was produced by the neutralization of sodium silicate solution. Rice Husks soaked in nitric acid produced the maximum amount of the sodium silicate solution and precipitated silica. Sodium oxide (Na2O) content and silica (SiO2) content in the sodium silicate solution were also determined. Extracted precipitated silica particles were characterized by Fourier transform infrared (FTIR), X-Ray diffraction and Optical microscopy techniques. The chemical composition of silica was confirmed by FTIR and SEM with EDX.. Highly pure amorphous silica was derived from rice husk ash was confirmed by XRD pattern. The morphology of the obtained materials was analyzed by SEM. At optimized conditions, a nano sized highly pure silica was produced with a high reactivity and 99.9% amorphous in form. This economic technology as applied to waste material also provides many benefits to the local agro industry. Thus this paper may be providing a low cost and simple method to prepare functional materials. Keywords: Rice husk ash, Silica gel, Minerals, Amorphous material, Agricultural bio-wast

Predictor Analysis of the Non-parametric Bulk Arrival Fuzzy Queueing System

In general, queueing methodology is most helpful for design the system and that may achieve the described performance level. This paper, we discuss the fuzzy queueing model with fuzzy parameter. First we construct the membership function of the fuzzy queueing character where the arrival and service rates are triangular fuzzy numbers. Consider the service node as k-phase and to provide the equal service rate in all the phases. Second we shows that the method for constructing the membership function of finite capacity queueing system. A pair of nonlinear program is developed to describe the family of crisp membership functions of finite capacity through which the membership functions of the system performance measures are derived. Finally, we obtain the lower and upper bound of the system performance measure at the different possibility level of alpha. Third we analyze the optimal level of the queueing system, this work extended in [13, 14]. A numerical example is solved successfully

Association between components of metabolic syndrome and elevated intraocular pressure

Background: Glaucoma is a group of eye diseases which result in damage to the optic nerve and ultimately vision loss. Elevated intraocular pressure (IOP) remains as the one major known risk factor for both the development and progression of glaucoma. Metabolic syndrome (MS) have been found to relate to elevated IOP. The aim of the study is to examine the association between MS and IOP by comparing central corneal thicknesses (CCT).Methods: The study was carried out with 169 subjects consists of 94 were clinically diagnosed MS patients and 75 are healthy controls. Serum fasting glucose, triglyceride and HDL cholesterol levels were measured, and waist circumference, body mass index and blood pressure of all patients were recorded. Ophthalmological examinations, including IOP and CCT measurements were done on everyone.Results: Higher IOP was observed in subjects with MS than those without MS. There was significant difference in the CCT values between the groups with and without MS (p<0.05). Most of the MS components were associated with IOP and CCT (p<0.05).Conclusions: The study concludes that components of MS have strong association with IOP and CCT. The prevalence of MS is increasing rapidly in developing countries and the main cause for MS is sedentary lifestyle. Since there is relationship between MS and IOP, lifestyle intervention might have therapeutic potential to reduce IOP. Further studies are warranted to bring about the possible underlying relationship between components of MS and IOP

A serological study of leptospirosis in Chennai

Background: Leptospirosis is a zoonotic disease of mammals caused by serovars belonging to the spirocheate Leptospira interrogans. Commonly occurs in tropical and sub tropical regions.Methods: A total number of 2180 suspected cases were included in the study during the period April 2014 to June 2014. All the samples were subjected to macroscopic slide agglutination test (MSAT). Suspected leptospirosis cases (n=2180) in the Chennai city and its suburbs were clinically evaluated.Results: The most common presentation involved was specific signs and symptoms including fever, myalgia and headache (99%). Fever followed by jaundice and renal failure were observed in 3.74% cases. Fever followed by chills, skin rashes, cough, vomiting were observed in 2.43% cases. About 30% of the infected people were found in the age group of above 60 years. Female (57 %) were found predominantly infected when compared to male (43 %). Out of 2180 suspected cases 534 (32%) were found infected due to leptospirosis during the summer by MSAT method. (April ’14-June’14).Conclusions: This study shows leptospirosis found more common among female than male, probably due to occupational status of leptospirosis. Based on our study we suggest that senior age group people (age more than 60 years) are highly proven to this disease probably due to the less immunity factor

The moderating effect of self-efficacy in the relationship between perceived job characteristics and work engagement / Ramesh Krishnan ... [et al.]

Although much research attention has been given to study the effect of perceived job characteristics on various work outcomes, few have specifically examined the joint effect of perceived job characteristics and self-efficacy on employee work engagement. This study aimed to examine the role of self-efficacy as a moderator in the perceived job characteristics-work engagement relationship. A total of 646 employees from the healthcare sector in Malaysia participated in this study. A moderated hierarchical regression analysis revealed a positive effect of job characteristics (autonomy, skill variety, feedback, task significance, task identity) with work engagement and a significant interaction between task identity and self-efficacy in predicting employee work engagement. Managerial implications and directions for future research are discussed

Histogenesis of Peyer’s patches in Ovine foetus (Ovis aries)

Tissue pieces of jejunum and ileum from different prenatal age groups of sheep were collected from Corporation slaughter house, Perambur, Chennai. By three months of foetal age in sheep, the Peyer’s patches appeared as an aggregation of lymphocytes in the propria submucosa of the jejunum and ileum. The lymphocytic aggregation appeared only in the antimesenteric part of the jejunum and ileum. By four months of foetal age, the circumscribed nodular aggregations of lymphocytes were found enlarged giving a follicle-like appearance. The capsular connective tissue was predominated by reticular fibres and a few collagen fibres. The dome area of the follicle consisted of closely packed small-sized lymphocytes which appeared darker than the basal area. The smooth muscle fibres of muscularis mucosae were not continuous throughout and were absent in the follicle having domes. In five months-old foetuses, the jejunal and ileal Peyer’s patches were distinctly observed as follicles. The follicle showed a distinct outer cortex and an inner lighter medulla. Numerous small-sized lymphocytes were observed in the outer cortex and few lymphoblasts, medium sized lymphocytes and reticular cells were observed in the medulla. Keywords: Histogenesis; Peyer’s patches; Ovine foetus

MORPHOGENESIS AND HlSTOMORPHOLOGY OF THE SCLERA IN LAYER AND BROILER CHICKEN*

ABSTRAC

Modulation of Hypoxia-Induced Pulmonary Vascular Leakage in Rats by Seabuckthorn (Hippophae rhamnoides L.)

Cerebral and pulmonary syndromes may develop in unacclimatized individuals shortly after ascent to high altitude resulting in high altitude illness, which may occur due to extravasation of fluid from intra to extravascular space in the brain, lungs and peripheral tissues. The objective of the present study was to evaluate the potential of seabuckthorn (SBT) (Hippophae rhamnoides L.) leaf extract (LE) in curtailing hypoxia-induced transvascular permeability in the lungs by measuring lung water content, leakage of fluorescein dye into the lungs and further confirmation by quantitation of albumin and protein in the bronchoalveolar lavage fluid (BALF). Exposure of rats to hypoxia caused a significant increase in the transvascular leakage in the lungs. The SBT LE treated animals showed a significant decrease in hypoxia-induced vascular permeability evidenced by decreased water content and fluorescein leakage in the lungs and decreased albumin and protein content in the BALF. The SBT extract was also able to significantly attenuate hypoxia-induced increase in the levels of proinflammatory cytokines and decrease hypoxia-induced oxidative stress by stabilizing the levels of reduced glutathione and antioxidant enzymes. Pretreatment of the extract also resulted in a significant decrease in the circulatory catecholamines and significant increase in the vasorelaxation of the pulmonary arterial rings as compared with the controls. Further, the extract significantly attenuated hypoxia-induced increase in the VEGF levels in the plasma, BALF (ELISA) and lungs (immunohistochemistry). These observations suggest that SBT LE is able to provide significant protection against hypoxia-induced pulmonary vascular leakage

Examining the Work Engagement-Organizational Citizenship Behavior Link: The Moderating Role of Employee Personality

Although previous researchers have paid significant attention to the effect of employee work engagement on employee involvement in organizational citizenship behavior (OCB), only a few have specifically examined the joint effects of employee work engagement and employee personality on employee involvement in OCB. Drawing upon the Social Exchange Theory, this study specifically examined the role of employee personality (agreeableness) as a moderator in the work engagement-OCB relationship. A total of 646 employees from three public healthcare institutions in Malaysia participated in this study. Moderated hierarchical regression results indicated a positive effect of work engagement with OCB and a significant interaction between work engagement and agreeableness personality in predicting OCB. However, the effect of work engagement on OCB was stronger for those respondents low in agreeableness than for those high in agreeableness personality, contrary to the hypothesis. Managerial implications and directions for future research are discussed