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In this study, a comparison is made between the Taguchi and the GRA strategy for enhancing the machinability of AA7178 metal matrix composites that are reinforced with SiC and TiO2 nanoparticles. The composites were produced using a stir casting method, and their machinability was studied using a lathe. The investigation that was carried out with the assistance of a scanning electron microscope (SEM) revealed that the reinforcement particles were dispersed uniformly over the surface of the aluminum matrix. The machining behavior of the composites was extensively investigated using the Taguchi approach and gray relational analysis. The feed had the greatest effect on the surface roughness of AA7178 + 3wt.% SiC(S1) and AA7178 + 3wt.% TiO2(T1) nanocomposites, respectively, as determined by ANOVA. In contrast, the cutting force for S1 and T1 nanocomposite was most affected by the depth of cut and the cutting speed. An examination of the variance of gray relationship grade revealed that cutting speed had a significant effect on both surface roughness and cutting force for S1 and T1, i.e., 59.76% and 71.40%, respectively. Abrasion and built-up edge were the primary causes of tool wear for both materials. [ABSTRACT FROM AUTHOR]

The purpose of this study was to explore the effect that stir casting has on a TiO2 and SiC nanoparticles reinforced aluminium matrix composite. In order to study the development of ceramic particle reinforced aluminium matrix composite, density, tensile strength, hardness, and fracture analyses were carried out. The scanning electron microscope (SEM) investigation showed that the reinforcement particles were distributed consistently throughout the aluminium matrix. Electron backscatter diffraction (EBSD) study revealed the grain refinement of composites on inclusion of nanoparticles. The results of the experiments revealed that addition of 3 weight percent TiO2 and SiC particles to AA7178 alloy led to an increase in both the maximum strength and the hardness properties but, the elongation percentage of the manufactured composites progressively deteriorated. From the fractured surface of tensile samples, a microstructural study showed that AA7178, AA7178/TiO2, and AA7178/SiC nanocomposites were showing both ductile and brittle behaviour because of micro-cutting and micro-voids. [ABSTRACT FROM AUTHOR]

This work compares evolutionary and statistical strategies for improving the wear behaviour of AA7178 metal matrix composites reinforced with SiC and TiO2 nanoparticles. The stir casting process was used to make the composites, and a pin-on-disc device was used in order to investigate the wear behaviour of the materials. The examination carried out using a scanning electron microscope (SEM) demonstrated that the reinforcement particles were distributed consistently over the surface of the aluminium matrix. Studies conducted using electron backscatter diffraction (EBSD) demonstrated that the incorporation of nanoparticles into composites brought to a finer grain structure in the finished product. The Taguchi technique and the particle swarm optimization (P.S.O) algorithm were used in order to optimize the data and conduct an in-depth analysis of the wear behaviour of the composites in comparison to the base alloy. The results showed that the sliding distance, applied load, and speed had the greatest impact on the wear rate for the base alloy matrix, AA7178 with 3wt.% TiO2 and AA7178 with 3wt.% SiC nanocomposite, respectively. The tribological properties of the composites were significantly enhanced when nanoparticles of silicon carbide and titanium dioxide were included into the material. [ABSTRACT FROM AUTHOR]

The present work was initiated to finalize resin for the development of thermal protection system (TPS) for the external surface of a polymeric composite rocket motor case made up of Carbon roving and Epoxy resin. The temperature on the outer surface of the composite case increases due to kinetic heating caused by aerodynamic drag and vehicle velocity. These rocket motor casings are functionally required only in the ascent phase of missile trajectory till motor action time and stage separation. Due to which the experienced heat flux is relatively less, and the temperature on the external composite case is in order of 250 °C - 300 °C depending on missile configuration & trajectory, unlike extreme thermal conditions on ablative nozzle liners exposed to rocket motor exhaust. The maximum allowable temperature in the present study for the Carbon-Epoxy case is 100 °C due to degradation in mechanical properties. The thermal protection system on the external surface will function as a heat-insulating layer based on the working mechanism of ablation. The resin of the thermal protection layer has a substantial impact on the manufacturing process and curing aspects, especially compatibility with the pre-cured carbon epoxy case layer. The generation of test results for thermal stability, cure characteristics and Tg for Epoxy resin has also been included in present studies as an additional objective that provides significant inputs for process development. The test results for Epoxy resin is also used as a basis for the finalization of resin for the thermal protection layer for processing aspects apart from its basic thermal stability characteristics. The ablative thermal protection working mechanism is based on the ablation phenomenon. In the case of ablation, resin plays a vital role due to pyrolysis and other thermal characteristics. In the present experimental studies, the Phenolic resin and Silicone resin are considered as candidate resin materials for ablative thermal protection system based on available literature and in house experience. The main objective of the present studies is to evaluate thermal stability, char yield after final decomposition through DSC and TGA techniques for both resins as these are fundamental characteristics needed for the present specific application. The test results for specific grades (formulation) of phenolic and Silicone resins are generated and compared. In the present work, the experimental studies to evaluate glass transition temperature (Tg), thermal stability, and cure characteristics for Epoxy resin is also carried through DSC. The test results of specific grade Epoxy resin provides a basis to assess thermal margins for resins selected for ablative thermal protection system and inputs for process development and design requirements. The scope of the present studies is aimed to finalize the resin system for external thermal protection of composite rocket motor case based on thermal characteristics test results and other compatibility aspects with the structural layer. [ABSTRACT FROM AUTHOR]

Background: Oral submucous fibrosis (OSMF) is a crippling slowly progressive disease of oral cavity that predominantly affects people habit of consuming areca nut and its commercial preparations which generates high levels of reactive oxygen species (ROS) during their metabolism. Objective: The objective of this present study is to evaluate the role of oxidative stress in causation and progression of OSMF by measuring the levels of nonenzymatic antioxidants in OSMF patients. Materials and Methods: For this study we selected 27 newly diagnosed OSMF patients of both sex with age group between 23 to 40 years and the same number of age and sex matched healthy individuals were selected as control group. In both the groups we measured plasma non enzymatic antioxidants like vitamin A. E, C and reduced glutathione. Total antioxidant activity was also assessed in both the groups. Results and Conclusions: We observed a very low levels of plasma non-enzymatic antioxidants (p < 0.001) and at the same time a very poor antioxidant activity (p < 0.001) in OSMF patients when compared to controls. Therefore, consumption of tobacco or areca quid creates an oxidative stress environment which might plays a major role in the causation of OSMF. [ABSTRACT FROM AUTHOR]

A nine year old Graded Murrah she buffalo, with a symptom of severe hemorrhage from a skin wound on left hind limb was diagnosed to have anacquired peripheral arteriovenous fistula. Diagnosis was made based on history, physical examination and radiography. Percutaneous ligatures were applied over the distended blood vessels which yielded marginal results. [ABSTRACT FROM AUTHOR]

The article presents a study on non-adherent, mesenteric and focally developed abscess in an eight year old Pomeranian bitch. The researchers observed a bitch that was presented with a complaint of constipation, inappettance and abdominal pain for four days to a collage hospital. They prepared the dog for aseptic surgery, which they premedicated with Atropine sulphate and anesthetized with Xylazine and Ketamine hcl anesthesia. They identified an independent abscess without any adhesions.

The article discusses a case of ankyloglossia in an Ongole calf. A nine-month-old Ongole calf with difficulty in feed intake was presented to a hospital in India. Clinical examination revealed that the calf was unable to protrude the tongue normally. Frenulum was also identified on the calf's tongue. The calf was successfully treated by a minor surgical intervention.