Root cause analysis (RCA) of fractured ASTM A53 carbon steel pipe at oil & gas company

Incident involving failures of ASTM A53 carbon steel (CS) pipe, connected to pressure safety valve (PSV) and carrying raw gas has caused serious supply disruption. This study was performed to identify the most probable cause of the pipe failure. It was conducted by reviewing the existing design, construction data and pipe material analysis using non-destructive techniques such as VT, PT, MT and UT along with metallographic, hardness and microscopic analysis. The investigation revealed that excessive material loss has occurred in both failure and its adjacent regions due to abrasive grinding, resulting in the formation of a through thickness flaw. These grindings were performed to accommodate the pre-installed piping spool to avoid alteration in the pipe position. RCA demonstrated that this rapid thinning of the steel pipe body later led to its failure. Metallurgical study using photomicrograph shows that the morphology of the steel material was consistent and did not show any evidence of internal corrosion or micro fractures. Further damage to the surface of already excessively reduced thickness occurred due to nominal pipe vibration and atmospheric effect during service. The research work described in the paper has a significant meaning to recognize the root cause of such failures in CS pipes and through given recommendations to eliminate future such happenings

Echocardiographic parameters and renal outcomes in patients with preserved renal function, and mild- moderate CKD

Abstract Background Echocardiographic characteristics across the spectrum of chronic kidney disease (CKD) have not been well described. We assessed the echocardiographic characteristics of patients with preserved renal function and mild or moderate CKD referred for echocardiography and determined whether echocardiographic parameters of left ventricular (LV) and right ventricular (RV) structure and function were associated with changes in renal function and mortality. Methods This retrospective cohort study enrolled all adult patients who had at least one trans-thoracic echocardiography between 2004 and 2014 in our institution. The composite outcome of doubling of serum creatinine or initiation of maintenance dialysis or kidney transplantation was the primary outcome. Mortality was the secondary outcome. Results 29,219 patients were included. Patients with worse renal function had higher prevalence of structural and functional LV and RV abnormalities. Higher estimated glomerular filtration rate (eGFR) was independently associated with preserved LV ejection fraction, preserved RV systolic function, and lower LV mass, left atrial diameter, pulmonary artery pressure, and right atrial pressure, as well as normal RV structure. 1041 composite renal events were observed. 8780 patients died during the follow-up. Pulmonary artery pressure and the RV, but not the LV, echocardiographic parameters were independently associated with the composite renal outcome. In contrast, RV systolic function, RV dilation or hypertrophy, LV ejection fraction group, LV diameter quartile, and pulmonary artery pressure quartile were independently associated with all-cause mortality. Conclusions Echocardiographic abnormalities are frequent even in early CKD. Echocardiographic assessment particularly of the RV may provide useful information for the care of patients with CKD.https://deepblue.lib.umich.edu/bitstream/2027.42/144773/1/12882_2018_Article_975.pd

Enhanced He-alpha emission from "smoked" Ti targets irradiated with 400nm, 45 fs laser pulses

We present a study of He-like 1s(2)-1s2p line emission from solid and low-density Ti targets under similar or equal to 45 fs laser pulse irradiation with a frequency doubled Ti: Sapphire laser. By varying the beam spot, the intensity on target was varied from 10(15) W/cm(2) to 10(19) W/cm(2). At best focus, low density "smoked" Ti targets yield similar to 20 times more He-alpha than the foil targets when irradiated at an angle of 45 degrees with s-polarized pulses. The duration of He-alpha emission from smoked targets, measured with a fast streak camera, was similar to that from Ti foils

X-ray Photoelectron Spectroscopy (XPS) and Magnetization Studies of Iron–Vanadium Phosphate Glasses

Vanadium phosphate glasses containing Fe2O3 with the chemical composition [(Fe2O3)x(V2O5)0.6−x(P2O5)0.4], where x=0.00, 0.10, 0.20, 0.25 and 0.30, have been prepared and investigated by X-ray photoelectron spectroscopy (XPS) and magnetic susceptibility measurements. The core level binding energies of V 2p, Fe 2p, P 2p and P 2s in the Fe2O3–vanadium phosphate glasses have been measured and shifts from the corresponding binding energies measured for V2O5, Fe2O3 and P2O5 powders are accounted for by changes in the next-nearest neighbor environment of these atoms in the P4O10 local structure. The O 1s spectra for the glasses are single, symmetric peaks arising from nearly 95% of the oxygen sites being occupied by non-bridging oxygen atoms. In addition, the broadened V 2p3/2 and Fe 2p3/2 spectra for the glass samples are decomposed into two peaks that are associated with the presence of V5+ and V4+ and Fe3+ and Fe2+, respectively. The magnetic susceptibility data appear to follow a Curie–Weiss behavior (χ=C/(T−θ)) for temperatures above ∼15 K with negative paramagnetic Curie temperatures indicative of antiferromagnetic interactions between the magnetic Fe3+, Fe2+ and V4+ ions. The experimentally determined Curie constants from the susceptibility data are in good agreement with the calculated values based on the Fe3+, Fe2+ and V4+ concentrations determined from the XPS analyses. Other qualitative features in the magnetic susceptibility results can be explained in terms of the formation of various magnetic clusters (single, dimer and trimer) with the introduction of the magnetic ions onto the P sites of the P4O10 structure

Degradation assessment of nuclear power plant extraction steam piping after long term service

Degradation due to ageing in a Nuclear Power Plant’s Extraction Steam Piping has been assessed. Samples of twelve years old seamless carbon steel SA 106B pipe have been taken and subjected to metallographic examination, hardness testing, radiographic examination and ultrasonic thickness measurement to investigate and analyze ageing in piping material. Metallographic examination of aged sample revealed irregularly distributed graphite nodules in ferrite grains and on grain boundaries as well, the reduction in pearlite phase has also been observed from 40% to 25%. This Transformation in microstructure has reduced hardness of steel. Reduction in hardness has found 20.4% and 0.7% on inner and outer layer of the pipe material respectively. Corrosion pits having average depth of 0.07 mm have been found on external surface. Radiograph of aged pipe revealed material removal and wall thinning due to erosion on inner surface of pipe. The extent of erosion had been checked, which has found 8.7%

A novel framework for software defined wireless sensor networks

© 2017 IEEE. A novel framework for software defined Wireless Sensor Networks (SDWSNs) is presented that draws on Software Defined Networking (SDN) concepts and capabilities to enhance control, management, and security, whilst reducing device complexity. These inherent complexities pose significant challenges toward the advancement of ubiquitous sensing and sensory data access through Sensing-as-a-Service (S2aaS) model. Therefore, it is advantageous to utilize SDN to decouple the control and the data forwarding planes and incorporate greater control over dynamic virtualization and approaches to improve the quality of experience. Enhanced algorithms can be applied on improved knowledge of the network conditions that is attainable when SDN is employed. We run simulations based on sensor flow model and provide a comprehensive analysis of the SDWSN framework, architecture and implementation constraints

Potential Drug-Drug Interactions in Psychiatric Ward of a Tertiary Care Hospital: Prevalence, Levels and Association with Risk Factors

Purpose: To identify the prevalence of potential drug-drug interactions (pDDIs) in a psychiatric ward, their levels and association with risk factors.Methods: This study was conducted in the psychiatric ward of Ayub Teaching Hospital, Abbottabad, Pakistan. Medical records of 415 patients were retrospectively reviewed for pDDIs using Micromedex Drug-Reax software. Logistic regression was applied to determine association of pDDIs with age, gender, hospital stay and number of drugs.Results: In our study, we identified total number of 825 pDDIs of 126 types, with median number of 1 pDDIs per patient. Overall 64.8 % of the patients had at least one pDDI; 27.2 % at least one major pDDI; and 58.5 % patients at least one moderate pDDI. Among 825 identified pDDIs, most were of moderate (75.6 %) or major (20.8 %) severity, good (66.4 %) or fair (29 %) type of scientific evidence; and delayed onset (71 %). The most frequent major and moderate pDDIs included haloperidol + procyclidine (127 cases), haloperidol + olanzapine (49), haloperidol + promethazine (47), haloperidol + fluphenazine (41), diazepam + divalproex sodium (40), haloperidol + trihexyphenidyl (37), lorazepam + divalproex sodium (34), fluphenazine + procyclidine (33) and olanzapine + divalproex sodium (32). There was significant association of occurrence of pDDIs with hospital stay of 7 days or longer (p = 0.005) and taking 7 or more drugs (p < 0.001).                                                       Conclusion: A high prevalence of pDDIs in the psychiatric ward was recorded, a majority of which were of moderate severity. Patients with long hospital stay and increased number of drugs were more exposed to pDDIs.Keywords: Drug-drug interactions, Potential drug-drug interaction, Prescriptions screening, Drug-related problems, Clinical pharmacy