Studies on the utilization of red mud for environmental application

Red mud is a waste by product generated from alumina processing industries which creates a number of environmental problems. Reports of the utilization of the red mud for the treatment of natural, industrial and domestic waste water are available in literature. Clean water and a clean environment are the today’s requirements. The use of one waste for the removal of another waste is a challenging job. The present dissertation is an embodiment of the investigations for developing simple inexpensive adsorbents by the modification of red mud for waste water purification. In laboratory scale, neutralization of highly alkaline red mud is carried out by acid and CO2 gas treatment and modified by calcination. In another method, red mud adsorbent is prepared by surface modification with the impregnation of an anionic surfactant SDS. After modification, the red mud is called as Activated red mud (ARM) which is used as an adsorbent. The adsorbents (ARM) are used for the removal of Pb(II), Cd(II) ions and organic safranin-O dye separately from aqueous solutions in batch mode. The adsorbents, before and after treatment are characterized by XRD, SEM, EDX, TGA-DSC, FTIR, UV-Visible, BET surface area .The AAS analytical techniques is used to measure the residual metal ion concentration in treated water. The activated red mud used for the removal of hazardous Pb(II) possess the rounded shape aggregate particles with surface area 67.10 m2/g and particle size in the range of 0.1–150 µm . The maximum adsorption capacity as calculated from Langmuir isotherm model is found to be 6.0273 mg/g at pH 4. The pseudo-second-order kinetics describes the adsorption process. The adsorption process is described by ion exchange mechanism. The maximum adsorption capacities of Cd(II) on activated red mud (ARM) are found to be 12.046 and 12.548 mg/g at temperature 293 and 303 K, respectively. The endothermic, spontaneous and feasible nature of adsorption is known from the thermodynamic parameters. The external mass transfer coefficient (kf ) is found to be 0.084 ×10 -3, 0.012 ×10 -3 at temperature 293 K and 9.9 ×10 -3, 11.5 ×10 -3 at 303 K which are evaluated by the McKay et al: and Weber–Mathews equation respectively. The desorption efficiency of Cd(II) is found to be 91.29% with 0.2 mol/L HCl. The BET surface area of the SDS/RM is found to be 67.10 m2/g. The maximum adsorption capacity of modified red mud (SDS/RM) is found to be 8.94 mg/g at temperature 308 K and pH 4 obtained from Langmuir isotherm model. The external mass transfer coefficient (kf ) value as obtained from McKay et al: equation is found to be 3.49 ×10¬¬-4 , 4.61 ×10 -4 at temperature 308 K and 2.13 ×10 -4, 3.11 ×10 -4 at 328 K obtained from Weber–Mathews equation .These values indicate the faster adsorption of safranin-O on the surface of ARM at lower temperature. The response surface methodology (RSM) is applied to examine the efficiency of the removal of safranin-O dye from aqueous solution by the activated red mud neutralized by CO2 gas. A 24 full factorial central composite design (CCD) method is used to evaluate the effects of adsorption parameters. The operating parameters for maximum uptake capacity of 9.768 mg/g is; adsorbent dose (0.62 g), temperature (29.06 ℃), pH (8.3) and initial safranin-O concentration (37.3 mg/L). At this optimum condition, the adsorption of safranin-O from aqueous solution is found to be 94.5%

Motion of an air bubble under the action of thermocapillary and buoyancy forces

A novel way to handle surface tension gradient driven flows is developed in the volume-of-fluid (VoF) framework. Using an open source Navier-Stokes solver, {\it Basilisk}, and the present formulation, we investigate thermocapillary migration of drops/bubbles in a surrounding medium. Several validation exercises have been performed, which demonstrate that the present solver is a robust one to investigate interfacial flows with variable surface tension. It is well known that it is a challenging task to numerically model the tangential and normal surface forces arising due to interfacial tension. We have shown that the present method does not require the artificial smearing of surface tension about the interface, and thus predicts the theoretical value of the terminal velocity of bubble/drop migrating due to an imposed temperature gradient very well. It is also demonstrated that the present solver provides accurate results for problems exhibiting the gravity and thermocapillary forces simultaneously, and useful for systems with high viscosity and density ratios.Comment: 30 pages, 16 figures, submitted to Computers and Fluid

Performance Efficiency Measurement of Airports: A Comparative Analysis of Airports Authority of India and Public Private Partnership

This article describes how to improve the overall efficiency and effectiveness of the aviation sector and also to source extra funding, the Government of India has paved the way for private investors through to a Public Private Partnership (PPP) model since the 1980s. This liberalization step in the Indian aviation market has minimized the institutional barriers which have hindered the freedom and flexibility of air transport operations among private investors. Now, competition within the aviation sector has become fiercer; the Airports Authority of India (AAI) and Public Private Partnership (PPP) in Indian airports are not only providing varied services, but also attracting consumers with new infrastructure and full modern facilities. The importance of this article is because after privatization, no studies have been conducted to examine the efficiency of Indian airports by using Data Envelopment Analysis (DEA). An output-oriented DEA model is employed to determine the efficiency score of airports by taking a sample of 15 airports, including airports run by PPP, for comparison. Output-oriented DEA calculates the efficiency by maximizing the outputs for a given level of inputs. Therefore, this article contributes to the existing literature on Indian airports. Based on available data, three variables - length of runways, terminal size and number of check-in counters, are used as inputs and two variables - passenger movement and aircraft movement, are used as outputs.N

Clinical and Bacteriological profiles of patients with Acute Cholangitis.

INTRODUCTION : Acute cholangitis, is an infection of the biliary system with a wide spectrum of clinical presentations. In its most severe form, it is life threatening and associated with significant morbidity and mortality. Stone in the CBD is the most common cause of acute cholangitis. Other causes of cholangitis are neoplasm, benign strictures, parasitic infections, post operative conditions like sump syndrome and post choledochoduodenostomy and congenital anomalies of the bile ducts. In patients with bacterial cholangitis, bacteremia is seen in 1/3rd of blood cultures. Over two-thirds of the bile cultures show mixed infection of two or more organisms. Empiric broad- spectrum antibiotics and prompt biliary decompression, the mainstay of therapy significantly improves outcomes. There is no study from India which compares etiology, microbiological profile, interventions and outcomes in patients with acute cholangitis from different regions of the country. There is also no Indian data evaluating anaerobic cultures (blood / bile) in patients with acute cholangitis. Aims and Objectives : 1) To study the etiological profile, clinical features, interventions and outcomes in patients with acute cholangitis from different regions of the country. 2) To study the bacteriological profile (aerobic and anaerobic) and antibiotic sensitivity in a subset of prospectively enrolled patients with acute cholangitis. CONCLUSIONS : The most common cause of biliary obstruction in patients with acute cholangitis is stone disease (Choledocholithiasis). Malignant disease is responsible for obstruction in 1/3 of patients. Ultrasound examination of abdomen is an effective, inexpensive and non-invasive test for diagnosis of biliary obstruction. It should be the initial imaging test performed in patients with acute cholangitis. Bacteremia with single organisms (Gram negative) is seen in 1/3rd of patients with acute cholangitis, Gram positive organisms are rare in blood cultures. More than 90% of bile cultures show positive growth with multiple organisms in 2/3rd of the cultures. Most common organisms are E.coli and Enterococcus, followed by Klebsiella and Pseudomonas. The bacteriological profile has not changed over time. It is the same in our patients over the past 5 years. Anaerobic bacteria were not grown in bile or blood in the present study

Occurrences of thrombocytopenia with valproic acid used for psychiatric indication

Background: The main aim of this study is to find out the effect of valproic acid on platelet count and to know the possible risk factors for thrombocytopenia in patients taking valproate (VPA).Methods: On 72 patients having psychiatric indication, a longitudinal observational study was designed and conducted from February 2012 to July 2013 at Department of Psychiatry (out-patient department) of Pt. Jawahar Lal Nehru Memorial Medical College and Dr. Bhim Rao Ambedkar Memorial Hospital, Jail Road, Raipur, Chhattisgarh. Platelet count was monitored and determined using an automatic coulter analyzer. The patients were followed up to 6 months. Statistical tool standard deviation ± was used for statistical analysis. p<0.05 is considered as statistically significant.Results: Total percentage of thrombocytopenia was found to be 12.5%; among that males constitute 9.8% and females 19.04%. The maximum number of cases falls in the age group between 51 and 60 years (55.5%). The major diagnostic group was reported to be consisted of mania (40.4%), followed by resistant cases of schizophrenia (25%) and then bipolar affective disorder (23.6%). The study indicated that maximum patients suffered from mild thrombocytopenia (11.1%) and (1.4%) patients have moderate thrombocytopenia. The mean time from exposure to VPA therapy to the first episode of thrombocytopenia was reported 92 days.Conclusions: Our findings underlined the importance of monitoring platelet counts in patients treated with VPA. This monitoring should be continued indefinitely on monthly basis. The studies indicate that the demands of more vigilant monitoring of patients should occur in age of 50-60 years, and result of entire studies indicates that females were found to be subjected to incidences of thrombocytopenia especially

India’s Trade Partnership with East African Community: Exploratory Results from Trade Indices

Since the initiation of economic reforms in 1991, India adopted an outward-oriented strategy for development. After inception of World Trade Organization (WTO) in 1995, the country initially relied on multilateral trade reforms for export growth, but slow progress of the Doha Round negotiations over the last decade caused it to explore the regional trade agreements (RTAs) route as well from 2003-04 onwards. While in the initial period India focused on deeper trade relationship with Asian partners, namely, Association of Southeast Asian Nations (ASEAN), Japan, South Korea etc. as preferential trade allies, the perceived need to diversify the export markets has led the country to focus on potential trade partners in Africa, Europe, North and Latin America as well in recent times. On the other hand, the economies of East Africa are also embracing the RTA route for their trade promotion and the growing Indian market offers an opportunity for them as well. The present analysis attempts to understand the trade potential between the five East African Community (EAC) countries and India in the sphere of merchandise and services trade by looking through various trade indices. The empirical results indicate that bilateral trade between the two regions have a strong potential, which can be aided further through policy reforms at both ends

Titania coated silica nanocomposite prepared via encapsulation method for the degradation of Safranin-O dye from aqueous solution: Optimization using statistical design

AbstractTitania coated silica nanoparticles, which were synthesized via nanoparticle encapsulation route, are employed to degrade safranin-O dye from aqueous solution under UV light irradiation and were characterized by FT-IR, XRD, FESEM, N2 adsorption-desorption method and Zeta potential measurement. The results showed that the nanoparticles have a core-shell structure composed of about 100nm of diameter of silica with several TiO2 fine particles in shell. After the degradation, this process is optimized through the response surface methodology (RSM). In this response study, photodegradation efficiency was evaluated by three main independent parameters such as catalyst dose, initial dye concentration and reaction time. Parameter sensitivity studies of the degradation efficiency of titania coated silica nanoparticles have shown 93.29% degraded under the optimal conditions of catalyst dose of 89.80mg/g, initial dye concentration of 17.61mg/L and reaction time of 12min. We cross-checked the predicted values of degradation efficiency with the experimental values and were found to be in good agreement (R2=0.9983 and adj-R2=0.9967)

DEVELOPMENT OF BILAYER TABLETS FOR IMMEDIATE AND CONTROLLED RELEASE OF ALLICIN

Objective: The purpose of this study was to develop and evaluate bilayer tablet for the immediate and controlled release of Allicin (Garlic Extract) for effective treatment of Hypertension.Methods: The immediate release layer was prepared by using super disintegrants-sodium starch glycolate and binder used xantham gum and the sustained release layer was prepared by using hydrophilic polymer like HPMC K 100 and PVP. Before preparation of the tablets, all the pre-formulation parameters were checked and the tablet of Allicin were prepared by direct compression method and was evaluated for physical characteristics like hardness, weight variation, drug content and friability. In vitro release of drug was performed USP type II dissolution test apparatus using phosphate buffer (pH 7.4) as dissolution media and dissolution was continued for 8 hrs for the sustained release layer.Results: It was found that all the formulations were within the limit of the standard. The drug release of the tablet was in the range of 66%-83% in 8 h.Conclusion: It was concluded that the F4 formulation showed the optimum result as a bilayer tablet for the effective treatment of hypertension.Â