Installation of high resistance grounding system on the ungrounded system at offshore platform

Single line to earth fault usually can be seen in the ungrounded system. The ungrounded system is used widely in offshore platforms due to its advantages over the overvoltage whenever a fault occurs in the power systems. Continuous production with less interruption is vital in the oil and gas industry to achieve the production rate target. The grounding system has evolved for the past years and improvements have been made to the ungrounded system that has been around the years in the industry. The ungrounded system has been the best grounding system when the power system needs to maintain its operation with the presence of tolerable fault such as the single line to earth fault. Some facilities have included the feature of tripping the main circuit breaker whenever there is ground fault on the non-critical equipment. This has been unproductive to the operation and time consuming in restarting the plant facility after power failure or shutdown. Kikeh offshore platform is having the same situation whenever the ground fault occurs the main circuit breaker tripped and affects the operation badly. The High Resistance Grounding (HRG) design has proved to be able to sustain the fault and at the same time allows the plant to continue operating without any unnecessary shutdown. This improves the downtime and increases productivity. Furthermore, arc hazards to personnel and the classification flammable gas area can be minimized

Study the Thermal Effect on Low Cost Lithium ions Battery

Lithium ions battery is a popular choice of battery to many smartphones manufacturer. Despite the constant revolution of smartphones in terms of hardware, batteries remained one of the most underdeveloped aspects. The surface temperature of the battery increased during charging of smart phone or phone left in the car in the hot and sunny days. It can cause fire hazard and explode, therefore it is important to understand temperature distribution in battery surface during heating and cooling. Under this project, low cost lithium ions batteries surface temperature distributions were studied to understand the risk during heating and cooling. There are three different capacities (1500 mAh; 2100 mAh and 2600 mAh) lithium ions batteries were used during experiments and analysis the result the determine the risk. It was found that battery capacities, time of heating and heating place have significant effect on thermal distribution that increases the risk of fire hazard and explosion

A prospective cohort study of the long-term effects of CPAP on carotid artery intima-media thickness in Obstructive sleep apnea syndrome

<p>Abstract</p> <p>Objective</p> <p>To examine the long-term effect of CPAP on carotid artery intima-media thickness (IMT) in patients with Obstructive sleep apnea syndrome(OSAS).</p> <p>Methods</p> <p>A prospective observational study over 12 months at a teaching hospital on 50 patients newly diagnosed with OSAS who received CPAP or conservative treatment (CT). Carotid IMT was assessed with B-mode Doppler ultrasound from both carotid arteries using images of the far wall of the distal 10 mm of the common carotid arteries at baseline, 6 months and 12 months.</p> <p>Measurements and results [mean (SE)]</p> <p>Altogether 28 and 22 patients received CPAP and CT respectively without significant differences in age 48.8(1.8) vs 50.5(2.0)yrs, BMI 28.2(0.7) vs 28.0(1.2)kg/m2, ESS 13.1(0.7) vs 12.7(0.6), AHI 38(3) vs 39(3)/hr, arousal index 29(2) vs 29(2)/hr, minimum SaO₂75(2) vs 77(2)% and existing co-morbidities. CPAP usage was 4.6(0.3) and 4.7(0.4)hrs/night over 6 months and 1 year respectively. Carotid artery IMT at baseline, 6 months, and 12 months were 758(30), 721(20), and 705(20)micron for the CPAP group versus 760(30), 770(30), and 778(30)micron respectively for the CT group, p = 0.002.</p> <p>Among those free of cardiovascular disease(n = 24), the carotid artery IMT at baseline, 6 months and 12 months were 722(40), 691(40), and 659(30)micron for the CPAP group (n = 12) with usage 4.5(0.7) and 4.7(0.7) hrs/night over 6 months and 12 months whereas the IMT data for the CT group(n = 12) were 660(20), 685(10), and 690(20)micron respectively, p = 0.006.</p> <p>Conclusions</p> <p>Reduction of carotid artery IMT occurred mostly in the first 6 months and was sustained at 12 months in patients with reasonable CPAP compliance.</p

The distinctive gastric fluid proteome in gastric cancer reveals a multi-biomarker diagnostic profile

<p>Abstract</p> <p>Background</p> <p>Overall gastric cancer survival remains poor mainly because there are no reliable methods for identifying highly curable early stage disease. Multi-protein profiling of gastric fluids, obtained from the anatomic site of pathology, could reveal diagnostic proteomic fingerprints.</p> <p>Methods</p> <p>Protein profiles were generated from gastric fluid samples of 19 gastric cancer and 36 benign gastritides patients undergoing elective, clinically-indicated gastroscopy using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry on multiple ProteinChip arrays. Proteomic features were compared by significance analysis of microarray algorithm and two-way hierarchical clustering. A second blinded sample set (24 gastric cancers and 29 clinically benign gastritides) was used for validation.</p> <p>Results</p> <p>By significance analysyis of microarray, 60 proteomic features were up-regulated and 46 were down-regulated in gastric cancer samples (<it>p </it>< 0.01). Multimarker clustering showed two distinctive proteomic profiles independent of age and ethnicity. Eighteen of 19 cancer samples clustered together (sensitivity 95%) while 27/36 of non-cancer samples clustered in a second group. Nine non-cancer samples that clustered with cancer samples included 5 pre-malignant lesions (1 adenomatous polyp and 4 intestinal metaplasia). Validation using a second sample set showed the sensitivity and specificity to be 88% and 93%, respectively. Positive predictive value of the combined data was 0.80. Selected peptide sequencing identified pepsinogen C and pepsin A activation peptide as significantly down-regulated and alpha-defensin as significantly up-regulated.</p> <p>Conclusion</p> <p>This simple and reproducible multimarker proteomic assay could supplement clinical gastroscopic evaluation of symptomatic patients to enhance diagnostic accuracy for gastric cancer and pre-malignant lesions.</p

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

A new high pressure equation of state for seawater

A new high pressure equation of state for water and seawater has been derived from the experimental results of Millero and coworkers in Miami and Bradshaw and Schleicher in Woods Hole. The form of the equation of state is a second degree secant bulk modulus K = Pv 0 (v 0−v p =K 0+AP+BP 2 K = K w 0+aS+bS 3 2 A = A w+cS+dS 3 2 B = B w+eS where ν 0 and ν P are the specific volume at 0 and P applied pressure and S is the salinity (ℵ). The coefficients K W O , A W , and B W for the pure water part of the equation are polynomial functions of temperature. The standard error of the pure water equation of state is 4.3 × 10 −6 cm 3 g −1 in ν W P . The temperature dependent parameters a, b, c, d, and e have been determined from the high pressure measurements on seawater. The overall standard error of the seawater equation of state is 9.0 × 10 −6 cm 3 g −1 in ν P . Over the oceanic ranges of temperature, pressure, and salinity the standard error is 5.0 × 10 −6 cm 3 g −1 in ν P . This new high pressure equation of state has recently (1979) been recommended by the UNESCO Joint Panel on Oceanographic Tables and Standards for use by the oceanographic community

Optimizing speedup performance of computational hydrodynamic simulations with UPC programming model

In this study, we exploit the advantages of Berkeley's Unified Parallel C (UPC) programming model to optimize the speedup performance of computational hydrodynamic (CHD) simulations, which constitute an important class of modelling tool for hydraulic engineering applications. A two-dimensional (2D) numerical model, termed UPC-CHD, is developed using the conservative forms of the Navier-Stokes (NS) continuity, momentum, and energy equations for viscous, incompressible, and adiabatic flow cases with the UPC model. The following numerical schemes are adopted for discretization in UPC-CHD: (1) a 2-step Lax-Wendroff explicit scheme for the temporal term; (2) a Roe linear approximation with a 3rd-order upwind biased algorithm for the convective fluxes; and (3) a central-differencing scheme for the viscous fluxes. The obtained speedup results demonstrate that UPC-CHD with the affinity principle achieves good speedup performance when compared to the serial algorithm, with an average value of 0.8 per unit core (thread) until 100 processor cores when simulating the Couette, Blasius boundary layer, and Poiseuille flows on a 2D domain of 100 million grids. Finally, we also investigate the effects of varying domain size on the speedup performances of UPC-CHD for the same flow conditions.Nanyang Technological UniversityThis research study is funded by the internal core funding from the Nanyang Environment and Water Research Institute (NEWRI),Nanyang Technological University (NTU), Singapore

Computational flood modeling with UPC architecture

Demand for effective flood modeling and forecasting based on the two-dimensional shallow water equations has increased due to uncertainties with climate changes and the need for further accuracy in the urbanized environment. In this study, an alternative parallel computing architecture is presented that uses the Unified Parallel C (UPC) architecture, which combines the respective advantages of message passing interface (MPI) scalability with the direct memory access of OpenMP. A second-order Godunov-type monotone upstream scheme flood model, called ParaFlood2D, is developed using UPC as the first approach. The computational efficiency of ParaFlood2D is investigated with two cases of flood wave propagation on shared-memory and distributed-memory systems. In both cases, the simulation results demonstrate reasonably good accuracy when compared with the respective analytical solutions. At the same time, the obtained speed-up performance of UPC is generally more favorable when compared with that of MPI and OpenMP in their respective basic designs. Overall, the study indicates that UPC parallel architecture can be a viable alternative for large-scale flood modeling simulations.Nanyang Technological UniversityThis research study is funded by the internal core funding from the Nanyang Environment and Water Research Institute, Nanyang Technological University (NTU), Singapore. The first author is grateful to NTU’s Interdisciplinary Graduate School for the 4-year Ph.D. scholarship for his study. The fourth author is grateful to NTU for the 4-year Nanyang President Graduate Scholarship for his current Ph.D. study