A STRUCTURED RELIABILITY AND MAINTAINABILITY ASSESSMENT MODEL: AN APPLICATION TO HIGH VOLTAGE MOTORS

Motors are one of the vital equipment and generally the higher in numbers in oil and gas processing facilities. The primary function is to drive the process equipment such as compressors, fans, pumps etc. Unreliability of the motors is a threat to safety but also to production loss and high operating expenditure. Motors experience higher failure rates and maintenance costs with age due to lower focus during useful life periods. In order to properly address the long-term reliability and maintainability of the motors and associated subsystems, this paper aims to propose a structured methodology and set of tools to ensure effective assessment. The proposed model mainly consists of data collection, analysis, assessment, financial analysis and later developed actions to properly address the concerns. Equipment failure and repair data is a challenge to any reliability assessment; hence, proposed methodology was introduced to collect, verify and validate the data. Later, multiple tools such as Pareto Analysis, Failure Mode and Effect Analysis and Root Cause Analysis were used to perform a detailed assessment. Weibull analysis was also explored to understand the failure modes, which ultimately helped in improving the availability of the motors. The proposed methodology has been applied to high-voltage motors to observe the effectiveness of the tools and proposed model in addressing reliability and maintainability. The results show significant reliability improvements of 12% (from 58% to 70%) and prove that the structured method can be effectively used in complex process facilities with significant benefits

Availability estimation and management for complex processing systems

“Availability” is the terminology used in asset intensive industries such as petrochemical and hydrocarbons processing to describe the readiness of equipment, systems or plants to perform their designed functions. It is a measure to suggest a facility’s capability of meeting targeted production in a safe working environment. Availability is also vital as it encompasses reliability and maintainability, allowing engineers to manage and operate facilities by focusing on one performance indicator. These benefits make availability a very demanding and highly desired area of interest and research for both industry and academia. In this dissertation, new models, approaches and algorithms have been explored to estimate and manage the availability of complex hydrocarbon processing systems. The risk of equipment failure and its effect on availability is vital in the hydrocarbon industry, and is also explored in this research. The importance of availability encouraged companies to invest in this domain by putting efforts and resources to develop novel techniques for system availability enhancement. Most of the work in this area is focused on individual equipment compared to facility or system level availability assessment and management. This research is focused on developing an new systematic methods to estimate system availability. The main focus areas in this research are to address availability estimation and management through physical asset management, risk-based availability estimation strategies, availability and safety using a failure assessment framework, and availability enhancement using early equipment fault detection and maintenance scheduling optimization

Determination of mercury (Hg) in two sea cucumber species Ohshimella ehrenbergii (Selenka, 1868) and Stolus buccalis (Stimpson, 1855) from the Karachi coast

In this study the amounts of mercury (Hg) were determined in tentacles and muscle tissues of O. ehrenbergii and S. buccalis from two coastal sites of Karachi; Buleji and Sunehri during Southwest monsoon (August and September) and Northeast monsoon (December and January) seasons of the year 2018. The mean amounts of Hg in edible tissues of sea cucumbers were as follows: O. ehrenbergii (0.0176 mg/kg dry wt.) and S. buccalis (0.0155 mg/kg dry wt.). Hg amounts in muscles of both species are much lower than the maximum permissible limits (0.5 mg/kg wet wt.). Estimated Daily Intakes for adults consuming O. ehrenbergii and S. buccalis are lower than published RfD values. Total Target Hazard Quotient (TTHQ) values (0.00787) are also lower than 1, it may be concluded that the consumption of these sea cucumbers from Karachi, do not pose any health hazards to human as Hg amounts were concerned

Culture‑proven disseminated Mycobacterium Bovis infection (BCG‑Osis) following intravesical BCG immunotherapy in a patient with bladder carcinoma‑in‑situ: ‘Case report’.

We are reporting a case of culture-proven disseminated Mycobacterium Bovis infection (BCG-Osis), involving lung, bone-marrow and urinary tract, after intravesical Bacillus Calmette–Guérin (BCG) immunotherapy for bladder carcinoma-in-situ. A 71-year-gentleman presented with fever shortly after intravesical BCG instillation. He was initially treated for presumed Urinary Tract Infection, but negative urine culture and persistent fever prompted us to consider alternative diagnoses. Empirical treatment for BCG-Osis was commenced after initial negative workup including blood culture, echocardiography, computed tomography (CT) Chest, and Kidney-Ureter-Bladder (KUB). However, he remained febrile and leukopenic, so bone-marrow examination was performed along with repeating CT Chest, which revealed non-caseating granulomas and small nonspecific pulmonary nodules, respectively, supporting our provisional diagnosis. Interestingly, Mycobacterium Bovis was finally isolated from one of his urine specimens, confirming our diagnosis

Comprehensive Energy Footprint Benchmarking of Strong Parallel Electrified Powertrain

In this paper we present a benchmark solution with higher number of continuous and discrete states and control levers using validated powertrain component models, where DP fails due to exponential rise in the computation time. The problem involves 13 states and 4 control levers, with complex interactions between multiple subsystems. Some of these variables are discrete while some are continuous. Some have slow dynamics while some have fast dynamics. A novel three step PS3 algorithm [1] which is presented in our prequel paper is used to obtain a near-optimal solution. PS3 algorithm makes use of pseudo spectral method for accurate state estimations. We present three scenarios where only fuel is minimized, only emissions are minimized and, lastly a combination of both fuel and emissions are minimized. All three cases are analyzed for their performance and computation time. The optimal compromise between fuel consumption and emissions are analyzed using a Pareto-front study. This large-scale powertrain optimization problem is solved for a P2 parallel hybrid architecture on a class 6 pick-up & delivery truck.Comment: Fixed typos, added discussio

Outcomes of Patients on Maintenance Hemodialysis Admitted to a Tertiary Care Hospital with COVID-19

Background: The coronavirus disease-2019 pandemic has caused a disastrous world health crisis. The patients with renal disease, particularly those who are receiving regular dialysis therapy have elevated risk of COVID-19 infection-associated complications as well as poor prognosis including enhanced risk of hospital admission, mechanical ventilation and mortality.Objective: The objective of the study is to assess the outcomes of patients on maintenance dialysis admitted to a tertiary care hospital with COVID-19.Material and Methods: This retrospective study was performed in a Tertiary Care Hospital from March 2020 to August 2020. A total of 44 patients were included in the study. Data collected through questionnaire was analyzed using the computer software SPSS 24.0. Frequencies and percentages were calculated for categorical data while mean+SD was calculated for quantitative data.Results: Among 44 patients, 63.6% were males and the mean age was 46.86+12.413 years. Mean number of dialysis were 3.57+2.214. The mean ferritin level was 2067.05+788.412 ng/ml and mean C-reactive protein level was 111.59+32.998 mg/L. Among these patients, 65.9% were discharged and 34.1% patients expired.Conclusion: Study concluded that elevated levels of inflammatory markers such as ferritin and CRP are found among patients on maintenance dialysis with COVID-19

Composition of major zooplanktonic groups in Shahbunder creek system - Indus deltaic area

A study was conducted in Shahbunder creek system, Indus deltaic area to observe the composition of major zooplanktonic groups during October – December, 1997 (post monsoon period). Total fourteen (14) major groups of zooplankton were recorded from two stations. Three groups copepod, chaetognatha and zoea constituted the major component of zooplankton at both the stations. Copepod was the most dominant group, constituting 50.50% at station # 1 and 46.12 at station # 2. Highest mean (15182.0±1402.14), (9343.66±4246.11) were measured in copepods at station# 1 and station# 2 respectively. This is the first attempt on ecological and zooplanktonic studies in Shahbander creek system. Hence, this study will enhance our knowledge on the creek ecosystem of Indus delta

Abundance and diversity of major zooplankton groups during premonsoon season in the Port Qasim creek system - Karachi

A preliminary study was conducted on the occurrence and faunastic composition of zooplankton in two creeks of Port Qasim creek system during January to April 1998 (pre-monsoon season). Total 14 major groups were recorded during the study period. Despite the importance of zooplankton in aquatic food web meager information is available on the assemblage of zooplankton in the port Qasim creek system. Highest mean (%) compositions (38.96) were recorded in copepod at station # 1 and chaetognath (23.95) at station # 2. Copepods, chaetognath and zoea were the major component of zooplanktonic groups at both the stations. The hydrographic parameters such as air temperature (oC), water temperature (oC), salinity (ppt), dissolved oxygen (mg/L), pH, and transparency (cm) were recorded on monthly basis. No significance correlation at (P < 0.05) was observed in between zooplankton with hydrographic parameters, locality and months. The number of zooplankton/100m3 found in order at station #1: copepod > chaetognath > zoea > penaeid PL > amphipoda > hydromedusae > caridean PL > fish larvae > lucifer > megalopa > fish eggs > mysids > acetes > squilla larvae. At station # 2: chaetognath > copepod > zoea > mysids > Lucifer > hydromedusae > megalopa > penaeid PL > fish larvae > fish eggs > amphipoda > caridean PL > others > acetes > squilla larvae

Tuberculosis verrucosa cutis in a patient with keloid over ear lobule

Tuberculosis (TB) is a global health problem with predominance in resource-poor countries. Extrapulmonary TB constitutes approximately 10% of the cases and can present as different forms depending on the route of entry. Cutaneous TB is a small subset of the extrapulmonary TB. Cutaneous TB can either be of primary origin or secondary origin or it can be a part of a systemic infection. TB verrucosa cutis (TBVC) is the exogenous reinfection of TB in a previously sensitised patient. Routine cultures do not have a high yield in TBVC due to the paucibacillary nature of the organism. Here we are presenting a rare case of a patient who developed in a keloid over the right ear lobule following ear piercing. This has only been presented once in the previous literature and for the first time in the head and neck region