Qualification of Indigenously Developed Special Coatings for Aero-Engine Components

The demand for higher performance and reliability of aero-engiaes necessitates its components to worksatisfactorily under severe operating conditions. The durability of various components in these environmentis often enhanced by applying suitable coatings. The development of new materials/processing methods andalso various coatings to protect the components have been driven by the ever-increasing severity of theaero-engine internal environment. While the selection of a coating is dictated by the operating conditionsand the nature of the environment and also on the substrate, the durability of the coating depends uponthe mode of degradation of the coating and substrate in service.Though certification of an aero-engine after developmt obviously includes: validation of the componentsand its coatings, indigenous substitution of an already-qualified component system requires a re-orientationof the qualification methodology. This paper describes an approach for qualification of indigenously developedspecial coatings processes for application on aero-engine components. This approach has been adoptedsuccesshlly in validating several indigenous coatingslpmcesses, viz, aluminium-silicon diffusion coating appliedby pack cementation for oxidationhot comsion resistance, cobalt-chromium carbide coating by electrodepositionfor wear resistance, chromium carbide-nickel chromium coating applied by detonation gun and yttria-stabilisedzirconia thermal barrier coating applied by plasma spray.The approaih consists of a series of validation tests configured to assess the coating-substrate system.The rationale in evolving the qualification tests based on the type of coating, coating process, operating conditionsfor the components, probable failure modes and coating-base metal interaction, are described. In addition,comparison of the test results obtained on the test specimens coated with indigenously developed coatingsand imported coatings is also enumerated to show that these coatings are comparable to the imported coatings.Documentation of satisfactory performance of the components coated with indigenously developed coatingsthrough successful engine tests and limited-service evaluation is also highlighted. In addition to the substitutionof the coatings recommended by the principal designers with those developed indigenously, a few coatings,such as polyimide coating for corrosion resistance and ceramic paint for thermal resistance solely appliedon various aero-engine components were successfully evaluated using above mentioned approach

A NOVEL APPROACH OF LOCUST BEAN GUM MICROSPHERES FOR COLONIC DELIVERY OF MESALAMINE

Objective: The objective of the present study was to formulate site-specific drug delivery of mesalamine using Locust bean gum.Methods: The core microspheres were prepared by ionic gelation method using CaCl2 solution and cross-linked with glutaraldehyde and were further coated with pH-sensitive polymer eudragit S-100(1.5-4.5 ml) to retard the drug release in the upper gastrointestinal environment (Stomach and small intestine). Microspheres were characterized by ftir spectroscopy, differential scanning calorimetry and evaluated by scanning electron microscopy (SEM), particle size analysis, entrapment efficiency and in vitro drug release studies in different simulated gastric fluids. Stability studies were carried out for one month at 40±2 °C/75±5% RH.Results: The SEM images revealed the surface morphology was rough and smooth for core and coated microspheres, respectively. The optimized batch (ILBG6) of core microspheres(for 7hr), coated microspheres and coated microspheres in presence of rat caecal contents (8%w/v) for 24hr exhibited 98.44±2.48, 73.58±3.49 % and 98.28±4.42 drug release, respectively. The drug release from all locust bean gum microsphere formulations followed higuchi kinetics. Moreover, drug release from Eudragit S-100 coated microspheres followed the korsmeyer-peppas equation with an fickian kinetics mechanism. Finally, stability studies suggested the change in entrapment efficiency and in vitro drug release of microspheres was minimal, indicating good stability of the formulation.Conclusion: The microspheres formed using natural polysaccharide locust beangum by ionic gelation method are capable of colon targeting the anti-inflammatory drug, mesalamine for the treatment of ulcerative colitis

Preparation of transversely isotropic test specimen of glass FRP composite - an innovative approach-I

FRP composites have attracted attention of researchers due to ever increasing demand for lighter and stronger materials from the industry, more so from aerospace and automotive sector. Researchers, particularly in academic institutions, are suffering due to non-availability of detailed information on fabrication techniques for preparing FRP test specimens that are equivalent to an analytical model. Accurate test specimen close to analytical model reduces the compulsion of going for unrealistic assumptions that takes the analysis away from reality. An easy to follow method to design, compute and achieve correct volume fraction is presented in this work. A technique for preparing and dismantling molds with commonly available materials is presented in detail. Using simple tools and tackles coupled with a few precautions followed as described herein, prospective researchers can fabricate FRP test specimen close to their requirement.&nbsp

Preparation of transversely isotropic test specimen of natural FRP composite - an innovative approach-II

Fiber Reinforced Plastic (FRP) composites can be broadly classified as synthetic and natural, based on the type of fibers incorporated. Abundantly available natural fibers like toddy palm, sisal, jute and banana are attracting the attention of researchers due to ever increasing demand for lighter, stronger and eco-friendly materials from the industry. However, natural fibers are limited in length, not so uniform in size and behave differently in different atmospheric conditions. Added to this, the inherent tendency of natural fibers to twist and curl in dry conditions poses many problems to researchers while preparing test specimens. Researchers in general and academicians in particular are handicapped by non-availability of relevant literature on fabrication techniques to prepare natural FRP composite test specimens close to their analytical models. Present paper addresses typical problems faced by researchers during preparation of unidirectional continuous fiber reinforced composite test specimen ensuring transversely isotropic nature. Using simple hand tools coupled with a few precautions taken as described herein, prospective researchers can condition natural fibers and prepare composite specimen to suit their requirements.&nbsp

Textural Properties of Sorghum Dough

Textural properties of dough prepared from the flours of eight sorghum cultivars were evaluated subjectively and also measured using a back-extrusion cell in an Instron Food Testing Instrument. The force and energy required for the extrusion of good quality cohesive dough were high. A poor quality dough was compressed into the cell without extrusion. The influence of flour-water-soluble components on dough conhesiveness are discusse

Prostate specific antigen: a new means as diagnostic and prognostic factor for breast cancer

ABSTRACT Prostate specific antigen (PSA) is a serine protease expressed at high levels in prostate epithelium and elevated PSA in serum is a well established marker, and also helps in management of prostate cancer. In recent times it has become widely accepted that PSA is also present in many non prostatic sources, creating doubts about the specificity of its tissue expression. Numerous studies have suggested that the molecular forms of PSA imply to signify a potential tool for the risk assessment of breast cancer. Studies have suggested new biological role of PSA in breast physiopathology. Additional studies are essential to enrol PSA indisputably as an additional means as diagnostic and prognostic tool for breast cancer. Here is the summary of how PSA has a potential to become a new diagnostic and prognostic tool

Identification of promising lines for yield from IR64/Akihikari Recombinant Inbred Lines under low nitrogen

Not AvailableFor identification of lines with promising yield under low nitrogen (N), a total of 117 Recombinant Inbred Lines (RILs) derived from IR64, an improved and released variety in Akihikari as recurrent parent, were evaluated for two seasons dry (Rabi) 2014 and wet (Kharif) 2015 under field with low and recommended N. The difference between the mean yields of the low and recommended N in both seasons was not significant indicating the differential genotypic response under low and recommended N and the difference between the means of season was about 30%, indicating the role of the season in determining the yield under differential N. Out of 50 promising lines identified for low and recommended N, six promising lines were identified with yields ranging from 11.2 ± 0.65 to 18.3 ± 1.06 (Dry 2014) and 7.1 ± 0.41 to 15.4 ± 0.89 (Wet 2015) under low N suggesting the possibility of evaluation of the mapping populations as a promising strategy for the identification of breeding lines with promising yield under low N.Not Availabl

Absence of Spontaneous Peroxisome Proliferation in Enoyl-CoA Hydratase/l-3-Hydroxyacyl-CoA Dehydrogenase-deficient Mouse Liver: FURTHER SUPPORT FOR THE ROLE OF FATTY ACYL CoA OXIDASE IN PPARα LIGAND METABOLISM

Peroxisomes contain a classical L-hydroxy-specific peroxisome proliferator-inducible beta-oxidation system and also a second noninducible D-hydroxy-specific beta-oxidation system. We previously generated mice lacking fatty acyl-CoA oxidase (AOX), the first enzyme of the L-hydroxy-specific classical beta-oxidation system; these AOX-/- mice exhibited sustained activation of peroxisome proliferator-activated receptor alpha (PPARalpha), resulting in profound spontaneous peroxisome proliferation in liver cells. These observations implied that AOX is responsible for the metabolic degradation of PPARalpha ligands. In this study, the function of enoyl-CoA hydratase/L-3-hydroxyacyl-CoA dehydrogenase (L-PBE), the second enzyme of this peroxisomal beta-oxidation system, was investigated by disrupting its gene. Mutant mice (L-PBE-/-) were viable and fertile and exhibited no detectable gross phenotypic defects. L-PBE-/- mice showed no hepatic steatosis and manifested no spontaneous peroxisome proliferation, unlike that encountered in livers of mice deficient in AOX. These results indicate that disruption of classical peroxisomal fatty acid beta-oxidation system distal to AOX step does not interfere with the inactivation of endogenous ligands of PPARalpha, further confirming that the AOX gene is indispensable for the physiological regulation of this receptor. The absence of appreciable changes in lipid metabolism also indicates that enoyl-CoAs, generated in the classical system in L-PBE-/- mice are diverted to D-hydroxy-specific system for metabolism by D-PBE. When challenged with a peroxisome proliferator, L-PBE-/- mice showed increases in the levels of hepatic mRNAs and proteins that are regulated by PPARalpha except for appreciable blunting of peroxisome proliferative response as compared with that observed in hepatocytes of wild type mice similarly treated. This blunting of peroxisome proliferative response is attributed to the absence of L-PBE protein in L-PBE-/- mouse liver, because all other proteins are induced essentially to the same extent in both wild type and L-PBE-/- mice

Increasing Trends of Leptospirosis in Northern India: A Clinico-Epidemiological Study

Leptospirosis is often not suspected by physicians in patients with acute febrile illnesses reporting from supposedly “non-endemic areas,” including north India. Clinical manifestations are protean, and complications can affect most organ systems, including liver, kidneys, lungs, and the central nervous system. Timely diagnosis and specific therapy can reduce severity of illness and, in turn, mortality. In this study conducted at a tertiary care center in north India, we find how a much-neglected disease entity has emerged as a major cause of acute febrile illness in a so called “non-endemic area.” Incidence is increasing yearly. The majority of patients were from a rural background, and were farmers or farm labourers. Poor hygiene, contact with animals, rat infestation of houses, and contact with stagnant dirty water are the major determinants of disease. Apart from the usual symptoms of intermittent fever with chill and rigor, hepatosplenomegaly, renal decompensation, muscle pain and tenderness, and conjunctival suffusion, signs and symptoms indicating involvement of the respiratory and central nervous systems were also commonly observed. Severe complications resulting in mortality do occur and is especially due to late suspicion among primary level physicians, and the resulting inappropriate therapy