41 research outputs found
Guidelines for the application of recycled concrete aggregate in the Egyptian construction Industry
Construction industry is one of the most important fractions of economy worldwide. This industry consumes enormous amounts of raw materials and produces considerable waste. The optimization of construction material usage not only saves costs but also can significantly contribute towards sustainable development. The concept of recycling the construction and demolition rubble is being addressed in this study as a solution. The recycling of concrete, resulting from both the construction activities and the demolition activities, in order to be used as a source of aggregate is being focused upon in this study. Although the idea of using recycled concrete has been implemented widely in the United States and European construction industries, one can find that the idea is still limited in most of the developing countries and Egypt is one of these nations as well. This study raises the questions of: Why the use of recycled concrete, as a source of aggregate, is still limited in Egypt and why are contractors and consultants still not encouraged to adopt the Recycled Concrete Aggregate notion even in small construction jobs? In order to address these questions, a survey has been performed within a wide range of entities that are involved in the construction and demolition waste industries in Egypt. Most of those entities have figured out that the absence of the codes of practices, field experiences, and the know-how, and the environmental and economic concerns are some of the main reasons behind these questions. The study introduces the problem and an overview on the situation in Egypt concerning the recycling of concrete. It tackles the development of the concept of concrete recycling and presents the past world experiences in the field of concrete recycling. Moreover, a survey questionnaire is being presented covering the situation in the Egyptian construction and demolition waste industries. It also provides the know-how of recycling concrete in the form of the layout of production plants, recycling process and crushing mechanisms. In addition, the material (Recycled Concrete Aggregate) performance and the environmental and economic concerns in recycling concrete are being tackled in the study. The study attempts to develop both an economic model to assess the national savings that could result from recycling concrete waste and also to evaluate the viability of creating markets for recycled concrete aggregate. Moreover, some specification limits for recycled aggregate properties are being proposed by the study. The overriding conclusions of the study reveal that the government should address codes of practices and should also address taxes, levies, and subsidies in order to encourage the application of concrete recycling. Some recommendations for future studies are also presented
Guidelines for the application of recycled concrete aggregate in the Egyptian construction Industry
Errors Analysis in Distance Relay Readings with Presence of FACTS Devices
This paper presents studying the performance of distance impedance relay with the presence of FACTS devices .Also the measured impedance at the relaying point in the presence of series FACTS device SSSC , and shunt FACTS device called STATCOM are obtained. A detailed model of both SSSC and STATCOM is introduced and then the faulty system is studied analytically , where the errors in the measured impedance of distance impedance relay are introduced as a result of the presence of series and shunt FACTS devices. The analysis results show the effect of impacting the FACTS devices location, the values of inserted SSSC and STATCOM voltages (operational conditions) and also the fault resistance values. Keywords: Distance Relay, FACTS, STATCOM, SSSC
Management for failed back surgery syndrome: three-in-one procedure versus percutaneous spinal fixation alone
Objectives: To evaluate the short-term outcome of a 3-in-1 procedure including percutaneous facet radiofrequency, percutaneous spinal fixation and steroid with hyaluronidase enzyme injection versus percutaneous spinal fixation alone for cases with failed back surgery syndrome (FBSS).Patients and methods: The study included 50 patients who had had previous spinal surgery since a mean duration of 39.7 ± 8.5 months and developed recurrent back pain since a mean duration of 10 ± 2.1 months. Patients were randomly allocated into two groups; group A underwent percutaneous spinal fixation only and group B underwent the 3-in-1 procedure. Outcome was evaluated at the end of six months postoperatively (PO) using a pain numeric rating scale (NRS), the Oswestry Disability Index (ODI) and Odom’s criteria for evaluation of surgical outcome with evaluation of patients’ satisfaction by outcome.Results: All patients showed progressive decrease of NRS pain and ODI scores compared with preoperative scores. However, patients in group B showed significantly lower postoperative NRS pain scores and ODI with significantly higher frequency of patients having had > 50% reduction of both scores compared with patients in group A. PO analgesic consumption rate in both groups was significantly lower than the preoperative rate with a significant reduction of mean total scoring compared with preoperative scoring. The frequency of patients who found the provided therapeutic procedure satisfactory and its outcome good-to excellent was significantly higher among patients in group B compared with group A.Conclusion: Short-term outcomes of the applied 3-in-1 procedure are promising for improvement of symptoms secondary to FBSS and may ultimately prove to be recommended as the therapeutic modality for such a challenging clinical problem.Keywords: failed spinal surgery, percutaneous facet radiofrequency, percutaneous spinal fixatio
Laparoscopic ovarian drilling-plus: a one-stop management approach for PCO-associated infertility
Background: The current study aims to estimate additional values of laparoscopic intervention for diagnosis and treatment of concomitant pelvic pathologies among infertile women with clomiphene-resistant polycystic ovarian syndrome (PCOS) subjected to laparoscopic ovarian drilling (LOD) in comparison to non-PCOS infertile women subjected to diagnostic/therapeutic laparoscopy.Methods: A prospective cross sectional observational study was carried out in the Endoscopic unit of a tertiary care university hospital. The study included 232 infertile women planned for laparoscopy were divided into a study group A (116 cases) with clomiphene-resistant PCOS and a control group B (116 cases) without PCOS. Each group was further subdivided into two subgroups according to the presence and absence of risk factors (RF) for adhesion formation. Diagnostic/operative laparoscopy was done. The main study outcome was the prevalence of any pelvic abnormalities seen during laparoscopy.Results: Both groups showed insignificant difference regarding socio-demographic history and basic data. Laparoscopy detected pelvic pathologies in 44 cases (37.9%) and 86 cases (74.1%) in both groups respectively. In group A, we diagnosed pelvic pathologies in 29 (32.6%) and 15 (55.6%) cases with and without RF respectively while in group B they were diagnosed in 76 (84.4%) and 10 (38.5%) cases with and without RF respectively. If compared to women with unexplained infertility, PCO patients without risk factors have an insignificant but higher prevalence of pelvic abnormalities. All concomitant pelvic pathologies in both groups were treated on a one-stop (see and treat) basis.Conclusions: Detection and proper management of associated pelvic pathologies at laparoscopy is a valuable additional advantage of LOD particularly in women with positive risk factors. LOD plus see and treat associated pathologies is a time saving and prompt management approach for women with PCO–associated infertility
An efficient electric charged particles optimization algorithm for numerical optimization and optimal estimation of photovoltaic models
The electric charged particles optimization (ECPO) technique is inspired by the interaction (exerted forces) between electrically charged particles. A developed version of ECPO called MECPO is suggested in this article to enhance the capability of searching and balancing the exploitation and exploration phases of the conventional ECPO. To let the search agent jumps out from the local optimum and avoid stagnation in the local optimum in the proposed MECPO, three different strategies in the interaction between ECPs are modified in conjunction with the conventional ECPO. Therefore, the convergence rate is enhanced and reaches rapidly to the optimal solution. To evaluate the effectiveness of the MECPO, it is executed on the test functions of the CEC’17. Furthermore, the MECPO technique is suggested to estimate the parameters of different photovoltaic models, such as the single-diode model (SDM), the double-diode model (DDM), and the triple-diode model (TDM). The simulation results illustrate the validation and effectiveness of MECPO in extracting parameters from photovoltaic models
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
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
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Summary
Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally.
Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies
have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of
the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income
countries globally, and identified factors associated with mortality.
Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to
hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis,
exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a
minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical
status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary
intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause,
in-hospital mortality for all conditions combined and each condition individually, stratified by country income status.
We did a complete case analysis.
Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital
diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal
malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome
countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male.
Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3).
Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income
countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups).
Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome
countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries;
p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients
combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11],
p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20
[1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention
(ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety
checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed
(ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of
parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65
[0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality.
Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome,
middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will
be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger
than 5 years by 2030