Resolving High Vibration On a Vertical Pump

Case StudyHigh vibration were observed on the motor, pump,structure for more than 2 years with 1X dominant motor vibration. Assuming that the issue is of complete structural issue even though this motor was running well in the past, some structural modifications have been carried out at site which includes a welding a mass of 100 Kg on the structure in addition to the installation of braces to the structure which did not yield any positive results. Structural measurement along with the ODS carried out at site did not reveal a significant issue with the structure itself except for the structural natural frequency slightly closer to the running frequency of the motor. The decision to carry out an onsite balancing on the motor which was intended to remove the excitation force yielded good results which exposed additionally a mistake in the balancing activities carried out by a local vendor at work shop

Resolving High Vibration On a Vertical Pump

Case StudiesThere is a single stage vertical pump installed in Acetic Acid area in a petrochemical plant. The unit is vertical high pressure (HP) reactor feed pump (High speed single stage, 230 kW, 12338 rpm & 3.444 gear ratio) driven by induction motor through a flexible shim pack coupling. High vibration levels were observed on the motor, pump and structure for more than 2 years with 1X dominant vibration (1X motor dominant frequency). Assuming that the issue is completely structural as this motor was running well in the past, there were some structural modifications have been carried out at site with inadequate engineering calculations. The modifications were welding a total mass of 100 kg onto the structure and the installation of braces to the structure which did not yield any positive results. A systematic structural measurement along with the Operating Deflection Shape carried out at site with the help of experts did not reveal a significant issue with the structure itself except for the structural natural frequency being slightly closer to the running frequency of the motor. The timely right decision by the experts to carry out an onsite balancing on the motor, which was intended to remove the excitation force, yielded good results which exposed a mistake in the balancing activities carried out by a local vendor at work shop. This case study is designed to outline how the high vibration issue was successfully diagnosed using various tests on site including the operating deflection shape, the root cause for the high vibration and finally how it was mitigated

Resolving High Vibration On a Vertical Pump

Case StudyHigh vibration were observed on the motor, pump,structure for more than 2 years with 1X dominant motor vibration. Assuming that the issue is of complete structural issue even though this motor was running well in the past, some structural modifications have been carried out at site which includes a welding a mass of 100 Kg on the structure in addition to the installation of braces to the structure which did not yield any positive results. Structural measurement along with the ODS carried out at site did not reveal a significant issue with the structure itself except for the structural natural frequency slightly closer to the running frequency of the motor. The decision to carry out an onsite balancing on the motor which was intended to remove the excitation force yielded good results which exposed additionally a mistake in the balancing activities carried out by a local vendor at work shop

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020

Analysis of Unconfined Compressive Strength of Rammed Earth Mixes Based on Artificial Neural Network and Statistical Analysis

Earth materials have been used in construction as safe, healthy and environmentally sustainable. It is often challenging to develop an optimum soil mix because of the significant variations in soil properties from one soil to another. The current study analyzed the soil properties, including the grain size distribution, Atterberg limits, compaction characteristics, etc., using multilinear regression (MLR) and artificial neural networks (ANN). Data collected from previous studies (i.e., 488 cases) for stabilized (with either cement or lime) and unstabilized soils were considered and analyzed. Missing data were estimated by correlations reported in previous studies. Then, different ANNs were designed (trained and validated) using Levenberg-Marquardt (L-M) algorithms. Using the MLR, several models were developed to estimate the compressive strength of both unstabilized and stabilized soils with a Pearson Coefficient of Correlation (R2) equal to 0.2227 and 0.766, respectively. On the other hand, developed ANNs gave a higher value for R2 than MLR (with the highest value achieved at 0.9883). Thereafter, an experimental program was carried out to validate the results achieved in this study. Finally, a sensitivity analysis was carried out using the resulting networks to assess the effect of different soil properties on the unconfined compressive strength (UCS). Moreover, suitable recommendations for earth materials mixes were presented

Coumarin derivatives as acetyl- and butyrylcholinestrase inhibitors: An in vitro, molecular docking, and molecular dynamics simulations study

Alzheimer's disease is an irreversible and progressive brain disease that can cause problems with memory and thinking skills. It is characterized by loss of cognitive ability and severe behavioral abnormalities, and could lead to death. Cholinesterases (ChEs) play a crucial role in the control of cholinergic transmission, and subsequently, the acetylcholine level in the brain is upgraded by inhibition of ChEs. Coumarins have been shown to display potential cholinesterase inhibitory action, where the aromatic moiety has led to the design of new candidates that could inhibit Aβ aggregation. Accordingly, the present work is an in vitro activity, along with docking and molecular dynamics (MD) simulation studies of synthesized coumarin derivatives, to explore the plausible binding mode of these compounds inside the cholinesterase enzymes. For this purpose, a series of previously prepared N1-(coumarin-7-yl) derivatives were screened in vitro for acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities. The assayed compounds exhibited moderate inhibitory activity against AChE, with IC50 values ranging from 42.5 ± 2.68 to 442 ± 3.30 μM. On the other hand, the studied compounds showed remarkable activity against BChE with IC50 values ranging from 2.0 ± 1.4 nM to 442 ± 3.30 μM. In order to better understand the ligand binding site interaction of compounds and the stability of protein-ligand complexes, a molecular docking with molecular dynamics simulation of 5000 ps in an explicit solvent system was carried out for both cholinesterases. We concluded that the tested coumarin derivatives are potential candidates as leads for potent and efficacious ChEs inhibitors

Neonatal mortality in a tertiary care private set up in Saudi Arabia

To ascertain Neonatal Mortality Rate (NMR), Early NMR (ENMR), Late NMR (LNMR), Corrected NMR (cNMR), and causes of neonatal mortality in a major tertiary care private maternity and Neonatal Intensive Care Unit (NICU) set up in Saudi Arabia. This was a retrospective analysis of hospital data. We ascertained 1-year data (from January 1, 2017 to December 31, 2017) from the electronic patient medical records database as well as the annual reports of four tertiary care labor and delivery rooms and NICU’s of Sulaiman Al Habib Medical Group (HMG). We obtained the total number of deliveries and neonatal outcomes and calculated overall NMR, ENMR, and LNMR rates per 1000 live births and stratified them by Sociodemographic Index (SDI). We analyzed the data using Microsoft Excel. The electronic patient records included data on 14,339 deliveries and 14,543 births (including twins and multiple births). We observed a total of 51 neonatal deaths (30: early, 21: late) resulting in NMR of 3.5/1000, ENMR of 2.06/1000, and LNMR of 1.44/1000. The deaths due to futility were 24 (47%), giving a cNMR of 1.8/1000. We found complications of extreme prematurity and congenital anomalies incompatible with life as the two major causes of death in our dataset. There was no death due to perinatal asphyxia. The NMR and cNMR were comparable to the most recent global, regional, and national data. The cNMR of a select population with high SDI served by a major private tertiary care set up was lower than the NMR of the global high SDI group. The high incidence of major and futile congenital anomalies warrants further study