Pitting studies of plain carbon steel in chloride containing borate buffer solution

Passivation is the process of temporary or permanent halt in degradation or corrosion rate of a metal due to the formation of different types of surface layers or films that protects the underlying metal. Pitting corrosion is the breakdown of the surface film due to presence of aggressive ions such as chloride ions. The breakdown of the passivity film is characterized by breakdown potential (Vc) which is dependent on the pH of the solution, concentration of the aggressive ions and the potential sweep rate. This study used the Point Defect Model to characterize the breakdown potential with respect to varying pH and concentration. The pH of the solution was kept a constant at 10.4. The breakdown potential is found to decrease with increasing chloride concentration and decrease with increasing pH. The cumulative distribution of the breakdown potential was found to be in well agreement with the experimentally obtained data. Optical micrographs showed stable and Meta stable pitting. The parameters from point defect model was found to be in well agreement with the experimental data

Role of acoustic radiation force impulse elastography, aminotransferase to platelet ratio index and fibrotest for the assessment of significant fibrosis and cirrhosis in chronic liver disease

Background: Accurate grading of hepatic fibrosis is important for the application of appropriate intervening strategy. Liver biopsy is the golden standard of fibrotic grading, however wide clinical application is hindered by its inherent drawbacks. Biomechanical-based ultrasonic elastography has received mass attention. However, several clinical studies found that the sole application of ultrasonic elastography may bring evident errors in diagnosing hepatic fibrosis. It is suggested that a combination of ultrasonic elastography and serum liver functions tests holds the potential to overcome those disadvantages. Aims and objectives was to study the diagnostic accuracy of ultrasonography elastography, APRI, fibrotest for significant fibrosis and cirrhosis in patients with chronic liver disease and established the correlation between ARFI elastography, APRI, Fibrotest in grading of liver fibrosisMethods: Sixty three patients with chronic liver disease were studied.  Liver stiffness was evaluated with ARFI elastography. Histologic staging of liver fibrosis served as the reference standard except a very few cirrhotic patients who were graded as cirrhotic on the basis of clinical examination. The required APRI, Fibrotest parameters and relevant clinical history was recorded.  Fibrosis stage was assessed according to the METAVIR classification.Results: ARFI, APRI, and Fibrotest demonstrated a significant correlation with the histological stage. According to ARFI and APRI for evaluating fibrotic stages more than F2, ARFI showed an enhanced diagnostic accuracy than APRI. The combined measurement of ARFI and APRI exhibited better accuracy than ARFI alone when evaluating ≥ F2 fibrotic stage that showed  significant concordance  i.e. 79.3% cases,  out of which 69.8% of total cases were correctly diagnosed on comparison with the gold standard. Fibrotest and ARFI elastography show significant concordance in grading of fibrosis i.e. 82.5%. Cases out of which 68.3% of total cases were correctly diagnosed on comparison with the gold standard.Conclusions: APRI, ARFI, and fibrotest are novel tools among non-invasive modalities to rule out significant fibrosis and cirrhosis in patients with chronic liver disease. ARFI with APRI and ARFI with fibrotest showed enhanced diagnostic accuracy than ARFI or APRI or fibrotest alone for significant liver fibrosis

A First Step Towards Automatically Building Network Representations

To fully harness Grids, users or middlewares must have some knowledge on the topology of the platform interconnection network. As such knowledge is usually not available, one must uses tools which automatically build a topological network model through some measurements. In this article, we define a methodology to assess the quality of these network model building tools, and we apply this methodology to representatives of the main classes of model builders and to two new algorithms. We show that none of the main existing techniques build models that enable to accurately predict the running time of simple application kernels for actual platforms. However some of the new algorithms we propose give excellent results in a wide range of situations

Visual, Optical and Replica Inspections: Surface Preparation of 650 MHz NB Cavity for PIP-II Linac

Surface preparation of niobium superconducting RF cavities is a critical step for achieving good RF performance under the superconducting state. Surface defect, roughness, and contamination affect the accelerating gradient and quality factor of the cavities. We report surface inspection methods used to control the surface processing of 650 MHz cavities designated for the pre-production and prototype cryomodules for PIP-II linac. The cavity surface was routinely inspected visually, with an optical camera, and by microscopic scanning of surface replicas. This article covers details on the surface inspection methods and surface polishing process used to repair the surface

Design and application of a multi-hazard risk rapid assessment questionnaire for hill communities in the Indian Himalayan region

The Indian Himalayan region (IHR) is prone to multiple hazards and suffers great loss of life and damage to infrastructure and property every year. Poor engineering construction, unplanned and unregulated development, and relatively low awareness and capacity in communities for supporting disaster risk mitigation are directly and indirectly contributing to the risk and severity of disasters. A comprehensive review of various existing survey forms for risk assessment has found that the survey questionnaires themselves have not been designed or optimised, specifically, for hill communities. Hill communities are distinctly different from low-land communities, with distinct characteristics and susceptibility to specific hazard and risk scenarios. Previous studies have, on the whole, underrepresented the specific characteristics of hill communities, and the increasing threat of natural disasters in the IHR creates an imperative to design hill-specific questionnaires for multi-hazard risk assessment. The main objective of this study is to design and apply a hill-specific risk assessment survey form that contains more accurate information for hill communities and hill-based infrastructure and allows for the surveys to be completed efficiently and in less time. The proposed survey form is described herein and is validated through a pilot survey at several locations in the hills of Uttarakhand, India. The survey form covers data related to vulnerability to earthquake (rapid visual screening), flood, high wind, landslide, industrial, non-structural falling hazards and fire hazards in the building, and climate change. SWOT (strengths, weaknesses, opportunities and threats) analysis of this study states that the proposed form has the advantages of being self-explanatory and pictorial, includes easy terminology, and is divided into various sections for better understanding by surveyors. This survey form has the weakness of being limited to specific hazards. There are opportunities for the form to be applied to other Himalayan countries like Bhutan, Nepal and Pakistan. When it is applied internationally, the options available in the questions may differ. The application process confirmed that the survey questionnaire performed well and met expectations in its application. The form is readily transferrable to other locations in the IHR and could be internationalised and used throughout the Himalayas.</p

Reliability of clinical methods in evaluating patellofemoral pain syndrome with malalignment

Background: Diagnosis of patellofemroal pain syndrome has been challenging due to lack of clinical test with better sensitivity and specificity, axial imaging has been considered as the standard modality for evaluation. Patients with anterior knee pain because of patellofemoral pain syndrome can be sub-grouped as those with or without radiological positive parameter for patellar maltracking.  The aim of the present study was to evaluate reliability of clinical tests in two subgroups of patients presenting with patellofemoral pain syndrome.Methods: 45 knees with anterior knee pain without any episode of patellar instability were evaluated clinically using four standard tests (patellar apprehension test (PAT), eccentric step test (EST), active instability test (AIT) and Waldron’s test. On the basis of CT scan finding (at least one positive radiological parameter of instability) 28 knees were categorized in Group A (potential patellar instability group) and 17 knees in Group B (PFPS).Results: All patients with 3 or more than three clinical test positive were cases with potential patellofemroal instability except two. Whereas other true patellofemroal pain patients all except 2 were have less than 3 positive clinical tests. Conclusions: Clinical test have more diagnostic accuracy in evaluating anterior knee pain due to potential patellofemroal instability in comparison to patellofemroal pain without radiological instability

Combined administration of taurine and monoisoamyl DMSA protects arsenic induced oxidative injury in rats

Arsenic is a naturally occurring element that is ubiquitously present in the environment. High concentration of naturally occurring arsenic in drinking water is a major health problem in different parts of the world. Despite arsenic being a health hazard and a well documented carcinogen, no safe, effective and specific preventive or therapeutic measures are available. Among various recent strategies adopted, administration of an antioxidant has been reported to be the most effective. The present study was designed to evaluate the therapeutic efficacy of monoisoamyl dimercaptosuccinic acid (MiADMSA), administered either individually or in combination with taurine post chronic arsenic exposure in rats. Arsenic exposed male rats (25 ppm, sodium arsenite in drinking water for 24 weeks) were treated with taurine (100 mg/kg, i.p., once daily), monoisoamyl dimercaptosuccinic acid (MiADMSA) (50 mg/kg, oral, once daily) either individually or in combination for 5 consecutive days. Biochemical variables indicative of oxidative stress along-with arsenic concentration in blood, liver and kidney were measured. Arsenic exposure significantly reduced blood δ-aminolevulinic acid dehydratase (ALAD) activity, a key enzyme involved in the heme biosynthesis and enhanced zinc protoporphyrin (ZPP) level. Clinical hematological variables like white blood cells (WBC), mean cell hemoglobin (MCH), and mean cell hemoglobin concentration (MCHC) showed significant decrease with a significant elevation in platelet (PLT) count. These changes were accompanied by significant decrease in superoxide dismutase (SOD) activity and increased catalase activity. Arsenic exposure caused a significant decrease in hepatic and renal glutathione (GSH) level and an increase in oxidized glutathione (GSSG). These biochemical changes were correlated with an increased uptake of arsenic in blood, liver and kidney. Administration of taurine significantly reduced hepatic oxidative stress however co-administration of a higher dose of taurine (100 mg/kg) and MiADMSA provided more pronounced effects in improving the antioxidant status of liver and kidney and reducing body arsenic burden compared to the individual treatment of MiADMSA or taurine. The results suggest that in order to achieve better effects of chelation therapy, co-administration of taurine with MiADMSA might be preferred

Development of bioconjugated nano-molecules against targeted microbial pathogens for enhanced bactericidal activity

The study reports development of bio-conjugated nano-molecules (BCM's) for enhanced antibacterial activity against targeted pathogens of global concern. The conjugation was achieved with biomolecular interaction of silver clusters with 3-Dichloro-5, 6-dicyano-1, 4-benzoquinone (DDQ) which was purified and characterized with TLC which displayed prominent band at R-f 0.5 and HPLC analysis displayed chromatographic peak eluting at (t(R)) 6-8 min. The LC-MS analysis displayed single major peak at t(R) = 4.610 corresponding to molecular ion peak at m/z = 227.19. The developed BCM molecule was determined with UV-Visible spectroscopy which displayed the absorbance peaks of conjugated molecules with shoulder peak observed and morphological characteristics were well defined with TEM analysis which showed cluster formation. The size ranged from 20 to 80 nm in size with majority of the BCM displaying spherical in size. The process of bio-conjugation was further studied with FTIR analysis which corresponded with different vibrational stretches owing to the presence of amide, carbonyl alkynes, nitriles and carboxylic acid groups. The presence of functional moieties was also studied using H-1 and C-13 NMR spectra. The crystalline characteristics was confirmed with XRD analysis which displayed Bragg's intensities along with additional peaks occurring at 2 theta angle corresponds to (111), (200), (220), (311) face centric cube of silver planes. The antibacterial activity of BCM's was profound against all the test pathogen which was validated and compared with standard antibiotics. Among the test pathogens, highest activity was conferred against Staphylococcus epidermidis (MTCC 435) with 29 mm. The minimal inhibition concentration of BCM's was in the range of 0.97-3.12 mu g/ml. The results of MIC were in accordance with well diffusion assay indicating the Gram + ve test pathogen Staphylococcus epidermidis to be the most sensitive. In addition, the broth dilution assay resulted in decrease in the optical density measured at 600 nm against the increase in the concentration of BCM's. The outcome of the present investigation revealed the role of bio-conjugation chemistry to increase fold activity against pathogens which can act as alternative tool to combat drug resistant menace across the globe