75 research outputs found

    EXPERIMENTAL INVESTIGATION OF TOOL WEAR AND INDUCED VIBRATION IN TURNING HIGH HARDNESS AISI52100 STEEL USING CUTTING PARAMETERS AND TOOL ACCELERATION

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    In machining of high hardness steel, vibration of cutting tool increases tool wear which reduces its life. Tool wear is catastrophic in nature and hence investigation of its assessment is important. This study investigates experimentally induced vibration during turning of hardened AISI52100 steel of hardness 54±2 HRC using coated carbide insert. In this context, cutting tool acceleration is measured and used to develop a novel mathematical model based on acquired real time acceleration signals of cutting tool. The obtained model is validated as R2= 0.93 while its residuals values closely follow the straight line. The predictions are confirmed by conducting conformity test which revealed a close degree of agreement with respect to the experimental values. The Artificial Neural Network (ANN) examination is performed to determine the model regression value. The study shows that the examined reports forecasts of ANN are more exact than regression analysis. The future directon of this investigation is towards developing a low-cost microcontroller-based hardware unit for in-process tool wear monitoring which could be beneficial for small scale industries

    Replication of Marek's Disease Virus Is Dependent on Synthesis of De Novo Fatty Acid and Prostaglandin E2

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    Marek’s disease virus (MDV) causes deadly lymphoma and induces an imbalance of the lipid metabolism in infected chickens. Here, we discovered that MDV activates the fatty acid synthesis (FAS) pathway in primary chicken embryo fibroblasts (CEFs). In addition, MDV-infected cells contained high levels of fatty acids and showed increased numbers of lipid droplets (LDs). Chemical inhibitors of the FAS pathway (TOFA and C75) reduced MDV titers by approximately 30-fold. Addition of the downstream metabolites, including malonyl-coenzyme A and palmitic acid, completely restored the inhibitory effects of the FAS inhibitors. Furthermore, we could demonstrate that MDV infection activates the COX-2/prostaglandin E2 (PGE2) pathway, as evident by increased levels of arachidonic acid, COX-2 expression, and PGE2 synthesis. Inhibition of the COX-2/PGE2 pathway by chemical inhibitors or knockdown of COX2 using short hairpin RNA reduced MDV titers, suggesting that COX-2 promotes virus replication. Exogenous PGE2 completely restored the inhibition of the COX-2/PGE2 pathway in MDV replication. Unexpectedly, exogenous PGE2 also partially rescued the inhibitory effects of FAS inhibitors on MDV replication, suggesting that there is a link between these two pathways in MDV infection. Taken together, our data demonstrate that the FAS and COX-2/PGE2 pathways play an important role in the replication of this deadly pathogen

    Delayed interval twin delivery of a fetus with a favourable neonatal outcome after a preterm delivery of the first twin: a case report

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    Assisted reproductive techniques have proved to be a boon for infertile couples. With advent of newer techniques, the incidence of successful multiple pregnancies has also risen. Considering the emotional and financial aspects of the treatment and the risk of preterm delivery in such cases, our intent is not only to salvage one of the twins in case of unfortunate preterm delivery of the other but also to deliver a viable second twin with better chance of survival and favourable neonatal outcome. The current case describes a 34-year woman with previous 2 failed IVF conceptions, on external progesterone support, carrying a twin gestation in preterm labour. Upon the inadvertent delivery of the first twin, a cervical cerclage was done, and she was given conservative management, including bed rest and head low position in view of short cervix, with an aim to delay the delivery of the other. An interval of 66 days was achieved with surgical as well as medical management, following which a healthy second twin was born

    Analysis of tool vibration and surface roughness with tool wear progression in hard turning: An experimental and statistical approach

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    The machined surface quality and dimensional accuracy obtained during hard turning is prominently gets affected due to tool wear and cutting tool vibrations. With this view, the results of tool wear progression on surface quality and acceleration amplitude is presented while machining AISI 52100 hard steel. Central Composite Rotatable Design (CCRD) is employed to develop experimental plan. The results reported that vibration signals sensed in a tangential direction (Vz) are most sensitive and found higher than the vibrations in the feed direction (Vx) and depth of cut direction (Vy). The acceleration signals in all three directions are observed to increase with the advancement of tool wear and good surface finish is observed as tool wear progresses up-to 0.136mm. The vibration amplitude is discovered high in the range 3 kHz – 10 kHz within selected cutting parameter range (cutting speed 60-180mm/min, feed 0.1-0.5mm/rev, depth of cut 0.1-0.5mm). The investigation is extended for the development of multiple regression models with regression coefficients value 0.9. These models found statically significant and give dependable estimates between a tool vibrations and cutting parameters

    Ultrastructure of the podium in Lamellidens corianus and Bellamya bengalensis.

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    Phylum mollusca comprise diverse kind of animals, which are able to live on every possible habitat present on the planet earth, except aerial one. Due to such a wide distribution all over the world, these animals showed highly evolved or specialized body characters. Adaptations made in the body characters of these animals made them fully efficient to counteract or withstand with the present atmospheric conditions. Amongst these body specializations, foot or podium of the molluscs showed highly evolved character during the course of evolution. Along with locomotion, it performs the various functions such as offensive and defensive, secretory and anchoring etc. due to such a key characters, it is become necessary to investigate the ultrastructure of the podium, so as to elucidate the detailed functions and structural adaptations made in the podium of the different class of the molluscs. In order to concered our knowledge regarding the ultrastructure, one molluscan species form class gastropoda and one from pelecypoda were investigated in detailed. Podium from these two molluscan species showed morphological differentiations along with cellular distributions. Present investigations provides the ultrastructural peculiarities of the compared molluscan species, which helps to understand the ecological impact on the development of the molluscan species

    Differentially expressed seed aging responsive heat shock protein OsHSP18.2 implicates in seed vigor, longevity and improves germination and seedling establishment under abiotic stress

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    Small heat shock proteins (sHSP) are a diverse group of proteins and are highly abundant in plant species. Although majority of these sHSPs were shown to express specifically in seed, their potential function in seed physiology remains to be fully explored. Our proteomic analysis revealed that OsHSP18.2, a class II cytosolic HSP is an aging responsive protein as its abundance significantly increased after artificial aging in rice seeds. OsHSP18.2 transcript was found to markedly increase at the late maturation stage being highly abundant in dry seeds and sharply decreased after germination. Our biochemical study clearly demonstrated that OsHSP18.2 forms homooligomeric complex and is dodecameric in nature and functions as a molecular chaperon. OsHSP18.2 displayed chaperone activity as it was effective in preventing thermal inactivation of Citrate Synthase. Further, to analyze the function of this protein in seed physiology, seed specific Arabidopsis overexpression lines for OsHSP18.2 were generated. Our subsequent functional analysis clearly demonstrated that OsHSP18.2 has ability to improve seed vigor and longevity by reducing deleterious ROS accumulation in seeds. In addition, transformed Arabidopsis seeds displayed better performance in germination and cotyledon emergence under adverse conditions as well. Collectively, our work demonstrates that OsHSP18.2 is an aging responsive protein which functions as a molecular chaperon and possibly protect and stabilize the cellular proteins from irreversible damage particularly during maturation drying, desiccation and aging in seeds by restricting ROS accumulation and thereby improves seed vigor, longevity and seedling establishment

    Association of Marek's Disease induced immunosuppression with activation of a novel regulatory T cells in chickens.

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    Marek’s Disease Virus (MDV) is an alphaherpesvirus that infects chickens, transforms CD4+ T cells and causes deadly lymphomas. In addition, MDV induces immunosuppression early during infection by inducing cell death of the infected lymphocytes, and potentially due to activation of regulatory T (Treg)-cells. Furthermore, immunosuppression also occurs during the transformation phase of the disease; however, it is still unknown how the disease can suppress immune response prior or after lymphoma formation. Here, we demonstrated that chicken TGF-beta+ Treg cells are found in different lymphoid tissues, with the highest levels found in the gut-associated lymphoid tissue (cecal tonsil: CT), fostering an immune-privileged microenvironment exerted by TGF-beta. Surprisingly, significantly higher frequencies of TGF-beta+ Treg cells are found in the spleens of MDV-susceptible chicken lines compared to the resistant line, suggesting an association between TGF-beta+ Treg cells and host susceptibility to lymphoma formation. Experimental infection with a virulent MDV elevated the levels of TGF-beta+ Treg cells in the lungs as early as 4 days post infection, and during the transformation phase of the disease in the spleens. In contrast to TGF-beta+ Treg cells, the levels of CD4+CD25+ T cells remained unchanged during the infection and transformation phase of the disease. Furthermore, our results demonstrate that the induction of TGF-beta+ Treg cells is associated with pathogenesis of the disease, as the vaccine strain of MDV did not induce TGF-beta+ Treg cells. Similar to human haematopoietic malignant cells, MDV-induced lymphoma cells expressed high levels of TGF-beta but very low levels of TGF-beta receptor I and II genes. The results confirm that COX-2/ PGE2 pathway is involved in immunosuppression induced by MDV-lymphoma cells. Taken together, our results revealed a novel TGF-beta+ Treg subset in chickens that is activated during MDV infection and tumour formation.Biotechnology and Biological Sciences Research Counci
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