35 research outputs found
Parametric Optimization of Taper Cutting Process using Wire Electrical Discharge Machining (WEDM)
Significant technological advancement of wire electrical discharge machining (WEDM) process has been observed in recent times in order to meet the requirements of various manufacturing fields especially in the production of parts with complex geometry in precision die industry. Taper cutting is an important application of WEDM process aiming at generating complex parts with tapered profiles. Wire deformation and breakage are more pronounced in taper cutting as compared with straight cutting resulting in adverse effect on desired taper angle and surface integrity. The reasons for associated problems may be attributed to certain stiffness of the wire. However, controlling the process parameters can somewhat reduce these problems. Extensive literature review reveals that effect of process parameters on various performance measures in taper cutting using WEDM is also not adequately addressed. Hence, study on effect of process parameters on performance measures using various advanced metals and metal matrix composites (MMC) has become the predominant research area in this field. In this context, the present work attempts to experimentally investigate the machining performance of various alloys, super alloys and metal matrix composite during taper cutting using WEDM process. The effect of process parameters such as part thickness, taper angle, pulse duration, discharge current, wire speed and wire tension on various performance measures such as angular error, surface roughness, cutting rate and white layer thickness are studied using Taguchi’s analysis. The functional relationship between the input parameters and performance measures has been developed by using non-linear regression analysis. Simultaneous optimization of the performance measures has been carried out using latest nature inspired algorithms such as multi-objective particle swarm optimization (MOPSO) and bat algorithm. Although MOPSO develops a set of non-dominated solutions, the best ranked solution is identified from a large number of solutions through application of maximum deviation method rather than resorting to human judgement. Deep cryogenic treatment of both wire and work material has been carried out to enhance the machining efficiency of the low conductive work material like Inconel 718. Finally, artificial intelligent models are proposed to predict the various performance measures prior to machining. The study offers useful insight into controlling the parameters to improve the machining efficiency
Parametric Optimization of Taper Cutting Process using Wire Electrical Discharge Machining (WEDM)
Significant technological advancement of wire electrical discharge machining (WEDM) process has been observed in recent times in order to meet the requirements of various manufacturing fields especially in the production of parts with complex geometry in precision die industry. Taper cutting is an important application of WEDM process aiming at generating complex parts with tapered profiles. Wire deformation and breakage are more pronounced in taper cutting as compared with straight cutting resulting in adverse effect on desired taper angle and surface integrity. The reasons for associated problems may be attributed to certain stiffness of the wire. However, controlling the process parameters can somewhat reduce these problems. Extensive literature review reveals that effect of process parameters on various performance measures in taper cutting using WEDM is also not adequately addressed. Hence, study on effect of process parameters on performance measures using various advanced metals and metal matrix composites (MMC) has become the predominant research area in this field. In this context, the present work attempts to experimentally investigate the machining performance of various alloys, super alloys and metal matrix composite during taper cutting using WEDM process. The effect of process parameters such as part thickness, taper angle, pulse duration, discharge current, wire speed and wire tension on various performance measures such as angular error, surface roughness, cutting rate and white layer thickness are studied using Taguchi’s analysis. The functional relationship between the input parameters and performance measures has been developed by using non-linear regression analysis. Simultaneous optimization of the performance measures has been carried out using latest nature inspired algorithms such as multi-objective particle swarm optimization (MOPSO) and bat algorithm. Although MOPSO develops a set of non-dominated solutions, the best ranked solution is identified from a large number of solutions through application of maximum deviation method rather than resorting to human judgement. Deep cryogenic treatment of both wire and work material has been carried out to enhance the machining efficiency of the low conductive work material like Inconel 718. Finally, artificial intelligent models are proposed to predict the various performance measures prior to machining. The study offers useful insight into controlling the parameters to improve the machining efficiency
Clinical and investigational study for the aetiological evaluation of patients in nontraumatic altered sensorium and its outcome
Background: Apart from head injury many patients present to the tertiary care hospital in unconscious state, the etiology of which is obscure in most of the cases. The present study was conducted with on objective to provide insight into the clinical features and diagnostic methods to know the aetiology of patients with non-traumatic cases of altered sensorium and to study the outcome of these patients.Methods: This is an observational study on 100 patients of altered sensorium of non-traumatic origin during the period from October 2012 to September 2014 conducted in the Department of General Medicine, MKCG Medical College Hospital, Berhampur, Odisha, India. All patients were selected for the study based on the inclusion exclusion criteria. Detailed history, clinical evaluation, laboratory investigations like neuroimaging studies etc. were carried out. Statistical data analysis was done using Graph pad Prism 6 and Microsoft Excel. P value <0.0001 was considered statistically extremely significant.Results: Out of 100 patients of altered sensorium, 64 were males and 36 were females. All patients were in the age group of 19 to 89 years. Cerebrovascular accident was the most common aetiology of altered sensorium followed by metabolic encephalopathy and infection. Altered sensorium in patients with CVA carries a high mortality. Metabolic causes and younger age indicated a better prognosis, patients with low (Glasgow Coma Score) GCS score of 3 to 4 had poorer prognosis.Conclusions: The results suggest that clinical assessments yield accurate predictive information about the potential for recovery in cases of altered sensorium. So, this study concludes that empirically based estimates of prognosis in the neurologically severely ill provides great reassurance to those involved in a decision-making process, including patients’ families and physicians
Association between unhygienic menstrual management practices and prevalence of lower reproductive tract infections: a hospital-based cross-sectional study in Odisha, India.
BACKGROUND: The extent to which reproductive tract infections (RTIs) are associated with poor menstrual hygiene management (MHM) practices has not been extensively studied. We aimed to determine whether poor menstrual hygiene practices were associated with three common infections of the lower reproductive tract; Bacterial vaginosis (BV), Candida, and Trichomonas vaginalis (TV). METHODS: Non-pregnant women of reproductive age (18-45 years) and attending one of two hospitals in Odisha, India, between April 2015 and February 2016 were recruited for the study. A standardized questionnaire was used to collect information on: MHM practices, clinical symptoms for the three infections, and socio-economic and demographic information. Specimens from posterior vaginal fornix were collected using swabs for diagnosis of BV, Candida and TV infection. RESULTS: A total of 558 women were recruited for the study of whom 62.4% were diagnosed with at least one of the three tested infections and 52% presented with one or more RTI symptoms. BV was the most prevalent infection (41%), followed by Candida infection (34%) and TV infection (5.6%). After adjustment for potentially confounding factors, women diagnosed with Candida infection were more likely to use reusable absorbent material (aPRR = 1.54, 95%CI 1.2-2.0) and practice lower frequency of personal washing (aPRR = 1.34, 95%CI 1.07-1.7). Women with BV were more likely to practice personal washing less frequently (aPRR = 1.25, 95%CI 1.0-1.5), change absorbent material outside a toilet facility (aPRR = 1.21, 95%CI 1.0-1.48) whilst a higher frequency of absorbent material changing was protective (aPRR = 0.56, 95%CI 0.4-0.75). No studied factors were found to be associated with TV infection. In addition, among women reusing absorbent material, Candida but not BV or TV - infection was more frequent who dried their pads inside their houses and who stored the cloth hidden in the toilet compartment. CONCLUSION: The results of our study add to growing number of studies which demonstrate a strong and consistent association between poor menstrual hygiene practices and higher prevalence of lower RTIs
Nox4 Mediates Renal Cell Carcinoma Cell Invasion through Hypoxia-Induced Interleukin 6- and 8- Production
Inflammatory cytokines are detected in the plasma of patients with renal cell carcinoma (RCC) and are associated with poor prognosis. However, the primary cell type involved in producing inflammatory cytokines and the biological significance in RCC remain unknown. Inflammation is associated with oxidative stress, upregulation of hypoxia inducible factor 1-alpha, and production of pro-inflammatory gene products. Solid tumors are often heterogeneous in oxygen tension together suggesting that hypoxia may play a role in inflammatory processes in RCC. Epithelial cells have been implicated in cytokine release, although the stimuli to release and molecular mechanisms by which they are released remain unclear. AMP-activated protein kinase (AMPK) is a highly conserved sensor of cellular energy status and a role for AMPK in the regulation of cell inflammatory processes has recently been demonstrated.We have identified for the first time that interleukin-6 and interleukin-8 (IL-6 and IL-8) are secreted solely from RCC cells exposed to hypoxia. Furthermore, we demonstrate that the NADPH oxidase isoform, Nox4, play a key role in hypoxia-induced IL-6 and IL-8 production in RCC. Finally, we have characterized that enhanced levels of IL-6 and IL-8 result in RCC cell invasion and that activation of AMPK reduces Nox4 expression, IL-6 and IL-8 production, and RCC cell invasion.Together, our data identify novel mechanisms by which AMPK and Nox4 may be linked to inflammation-induced RCC metastasis and that pharmacological activation of AMPK and/or antioxidants targeting Nox4 may represent a relevant therapeutic intervention to reduce IL-6- and IL-8-induced inflammation and cell invasion in RCC
Multi-objective optimization of WEDM taper cutting process using MOPSO based on crowding distance
Damage detection in structural elements: using adaptive Mamdani model
In real life all the structural and machine elements work under dynamic or variable loading. Application of dynamic loading leads to fluctuating stress. Due to fluctuating stress fatigue cracks initiates. These fatigue cracks are the main reason of failures. So, it is very important to detect the crack and predict the crack life. There are different types of damages but crack is one of the most encountered damage. There are different conventional methods to detect the damage but these methods are time taking and requires removal from the machines. Therefore, researchers are giving more importance to the unconventional methods to find the damage. In the present work a method has been introduced to find the damage site using Fuzzy Logic System and Regression Analysis. In particular, this paper focuses on applying statistical process control methods. A data pool has been created from the dynamic analysis of the cracked cantilever beam and then the data pool is trained in the proposed methodology to find the crack location. It has been noticed that the proposed methodology gives result within the tolerable range
Cobalt-rich lithiophorite from the Precambrian Eastern Ghats manganese ore deposit of Nishikhal, south Orissa, India
Fine-grained aggregates of lithiophorite are associated with cryptomelane, romanèchite, birnessite and graphite in the Precambrian Eastern Ghats manganese ore deposit of Nishikhal, south Orissa, India. High-cobalt lithiophorite is reported for the first time from the manganese ores. The mode of occurrence and the chemical composition of the lithiophorite are discussed. Along with manganese and aluminium, the lithiophorite contains appreciable quantities of CoO (1.59-8.56%) together with trace amounts of Cu, Ni, Zn, Ti, Ca, Mg, Na, K and P. The Nishikhal lithiophorite is a transition metal-rich lithiophorite
35 Obese microenvironmental signaling and junctional protein disruption in endometrial cells: an early pro-oncogenic change?
Objectives: The purpose of this study is to describe the impact of paracrine signaling of plasminogen activator inhibitor-1 (PAI-1) and interleukin-6 (IL-6) on endometrial epithelial junctional proteins in an obese microenvironment in order to gain insight into non-hormonal mechanisms of endometrial oncogenesis in the obese population. Methods: Immortalized endometrial epithelial cells (EM-E6/E7/TERT) were cultured and treated with PAI-1 (0.5 nM) and IL-6 (10 ng/mL). Cells were assessed for changes in junctional complex gene transcription, protein expression, and cellular proliferation and migration, via quantitative real time polymerase chain reaction (qRT-PCR), Western blotting, and Incucyte-based functional assays of proliferation. Immunofluorescence (IF) staining and confocal microscopy were used to highlight changes in connexin 32 (Cx32) encoded by the gap junction gene GJB1. These experiments were repeated in another established endometrial epithelial cell line (hEM3). Results: Transcription of GJB1 and corresponding protein connexin 32 (Cx32) levels were reduced when EME-E6/E7/TERT cells were treated with both PAI-1 and IL-6. This reduction in Cx32 levels with PAI-1 and IL-6 treatments was also seen in the hEM3 cells. Conclusions: The decline of Cx32 levels in the setting of PAI-1 and IL-6 exposure indicates that PAI-1 and IL-6 contribute to important dysregulatory changes within the endometrial epithelial junctional complex proteins. This assertion is strengthened by concordant findings in a separate endometrial epithelial cell line. Reduction in Cx32 production has previously been associated with endometrial hyperplasia and carcinoma. The findings of this study link obesity-related paracrine signaling to this phenomenon, which provides further information about causality between obesity and endometrial cancer. More research is required to investigate if IL-6 or PAI-1 would serve as a suitable therapeutic target in the management of endometrial hyperplasia or malignancy in obesity