124 research outputs found

    Design of an Intelligent Traffic Light Control System

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    Today, the number of cars is rapidly increasing which creates a real traffic control problem. While the conventional traffic control systems are inconvenient to provide fast and fair solutions for the congestion problem. This research addresses the traffic control problem and hence proposes an intelligent traffic light control system. In particular, the proposed system senses the presence or absence of cars on each lane, and then estimates the time to open each lane, which is proportional to the number of cars on that lane. Practically, the system circuit has been printed on a board with three main components; namely pressure sensors, microcontroller, and traffic lights. Then a C program has been developed to enable the microcontroller for receiving inputs from sensors, calculating the times to open lanes and sending appropriate logic decisions to traffic light. The obtained results prove the accuracy and reliability of the system.    In addition to the practical test, the intelligent traffic light control system has been successfully simulated, where the simulation results are found to be the same as the calculated ones

    Efficacy, persistence and vector susceptibility to pirimiphos-methyl (ActellicÂź 300CS) insecticide for indoor residual spraying in Zanzibar

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    Background Indoor residual spraying (IRS) of households with insecticide is a principal malaria vector control intervention in Zanzibar. In 2006, IRS using the pyrethroid lambda-cyhalothrine was introduced in Zanzibar. Following detection of pyrethroid resistance in 2010, an insecticide resistance management plan was proposed, and IRS using bendiocarb was started in 2011. In 2014, bendiocarb was replaced by pirimiphos methyl. This study investigated the residual efficacy of pirimiphos methyl (ActellicÂź 300CS) sprayed on common surfaces of human dwellings in Zanzibar. Methods The residual activity of Actellic 300CS was determined over 9 months through bioassay tests that measured the mortality of female Anopheles mosquitoes, exposed to sprayed surfaces under a WHO cone. The wall surfaces included; mud wall, oil or water painted walls, lime washed wall, un-plastered cement block wall and stone blocks. Insecticide susceptibility testing was done to investigate the resistance status of local malaria vectors against Actellic 300CS using WHO protocols; Anopheline species were identified using PCR methods. Results Baseline tests conducted one-day post-IRS revealed 100 % mortality on all sprayed surfaces. The residual efficacy of Actellic 300CS was maintained on all sprayed surfaces up to 8 months post-IRS. However, the bioassay test conducted 9 months post-IRS showed the 24 h mortality rate to be ≀80 % for lime wash, mud wall, water paint and stone block surfaces. Only oil paint surface retained the recommended residual efficacy beyond 9 months post-IRS, with mortality maintained at ≄97 %. Results of susceptibility tests showed that malaria vectors in Zanzibar were fully (100 %) susceptible to Actellic 300CS. The predominant mosquito vector species was An. arabiensis (76.0 %) in Pemba and An. gambiae (83.5 %) in Unguja. Conclusion The microencapsulated formulation of pirimiphos methyl (Actellic 300CS) is a highly effective and appropriate insecticide for IRS use in Zanzibar as it showed a relatively prolonged residual activity compared to other products used for the same purpose. The insecticide extends the residual effect of IRS thereby making it possible to effectively protect communities with a single annual spray round reducing overall costs. The insecticide proved to be a useful alternative in insecticide resistance management plans

    Multiple Assessments on the Gamma-Ray Protection Properties of Niobium-Doped Borotellurite Glasses: A Wide Range Investigation Using Monte Carlo Simulations

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    In this study, the monotonic effect of Ta2O5 and ZrO2 in some selected borotellurite glasses was investigated in terms of their impact on gamma-ray-shielding competencies. Accordingly, three niobium-reinforced borotellurite glasses (S1: 75TeO2 + 15B2O3 + 10Nb2O5, S2: 75TeO2 + 15B2O3 + 9Nb2O5 + 1Ta2O5, and S3: 75TeO2 + 15B2O3 + 8Nb2O5 + 1Ta2O5 + 1ZrO2) were modelled in the general-purpose MCNPX Monte Carlo code. They have been defined as an attenuator sample between the point isotropic gamma-ray source and the detector in terms of determining their attenuation coefficients. To verify the MC results, attenuation coefficients were then compared with the Phy-X/PSD program data. Our findings clearly demonstrate that although some behavioral changes occurred in the shielding qualities, modest improvements occurred in the attenuation properties depending on the modifier variation and its magnitude. However, the replacement of 2% moles of Nb2O5 with 1% mole of Ta2O5 and 1% mole of ZrO2 provided significant improvements in both glass density and attenuation properties against gamma rays. Finally, the HVL values of the S3 sample were compared with some glass- and concrete-shielding materials and the S3 sample was reported for its outstanding properties. As a consequence of this investigation, it can be concluded that the indicated type of additive to be added to borotellurite glasses will provide some advantages, particularly when used in radiation fields, by increasing the shielding qualities moderately. © 2022 H. O. Tekin et al

    Heavy metal oxide (HMO) glasses as an effective member of glass shield family: A comprehensive characterization on gamma ray shielding properties of various structures

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    Using advanced Monte Carlo simulation techniques and theoretical methodologies, a thorough investigation on the gamma-ray shielding properties of several heavy metal oxide glasses were performed. The general-purpose Monte Carlo code MCNPX (version 2.7.0) was used to simulate gamma-ray transmission to determine fundamental attenuation coefficients. The acquired findings were compared to Phy-X/PSD to confirm that the outputs were consistent. Additionally, other gamma-ray shielding parameters were computed and studied throughout a broad photon energy range of 0.015 MeV–15 MeV. From A to F glass samples, a sharp density increase from 5.99 g/cm3 to 8.9 g/cm3 was found. As a result, the F sample was found to have the highest linear attenuation coefficients. Our results indicate that increasing the amount of Bi reinforcement improved the material's overall gamma-ray attenuation properties. The F sample with the highest Bi reinforcement in its glass structure was subsequently shown to have superior gamma-ray shielding characteristics. Finally, we compared the F sample's half-value layer values to those of other commercial glass shields, various concretes, and other glass shields investigated in the literature. As a consequence of the benchmarking procedure, it has been determined that the F sample has better shielding capabilities than other shielding materials. It can be concluded that heavy metal oxide glasses offer apparent benefits in terms of more efficiently attenuating incoming gamma-rays. Additionally, it can be concluded that applying high Bi to heavy metal oxide glasses is a beneficial strategy for improving the gamma-ray attenuation capabilities of heavy metal oxide glasses. © 2022 The Author(s)Princess Nourah Bint Abdulrahman University, PNUAuthors express their sincere gratitude to Princess Nourah bint Abdulrahman University Researchers Supporting Project

    Transmission Factor (TF) Behavior of Bi2O3–TeO2–Na2O–TiO2–ZnO Glass System: A Monte Carlo Simulation Study

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    The main objective of the present work was to assess the gamma radiation shielding competencies and gamma radiation transmission factors (TFs) for some tellurite glasses in the form of Bi2O3–TeO2–Na2O–TiO2–ZnO. MCNPX general-purpose Monte Carlo code (version 2.6.0) was utilized for the determination of TF values at various well-known radioisotope energies for different glass thicknesses from 0.5 cm to 3 cm. Moreover, some important gamma ray shielding properties were also determined in the 0.015–15 MeV energy range. The results show that glass densities were improved from 5.401 g/cm3 to 6.138 g·cm3 as a function of Bi2O3 increment in the glass composition. A S5 glass sample with the maximum Bi2O3 additive was reported with superior gamma ray shielding properties among the studied glasses. It can be concluded that Bi2O3 can be used as a functional tool in terms of improving glass density and, accordingly, gamma ray shielding attenuation properties of tellurite glasses, where the role Bi2O3 is also critical for other material properties, such as structural, optical, and mechanical. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.This work was performed under Princess Nourah bint Abdulrahman University Researchers Supporting Project Number (PNURSP2022R149), Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia. The authors express their sincere gratitude to Princess Nourah bint Abdulrahman University

    Transmission factors, mechanical, and gamma ray attenuation properties of barium-phosphate-tungsten glasses: Incorporation impact of WO3

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    The purpose of this study is to conduct a thorough examination of the direct and indirect impacts of increasing the quantity of heavy WO3 on gamma-ray transmission, shielding and mechanical properties for some selected barium-phosphate-tungsten glasses. Accordingly, mechanical properties of barium-phosphate-tungsten oxides with chemical formula (50-x)P2O5-50BaO-xWO3 (x = 0.0(S1), 5.0(S2), 10(S3), and 15(S4)) mol% was evaluated using Makishima-Mackenzie model. Next, newly online Phy-X/PSD software and Monte Carlo code were used to examine the gamma radiation characteristics. Gamma-ray transmission factor (TF) values were calculated for S1, S2, S3 and, S4 glass samples for a range of well-known radioisotope energies such for 67Ga, 57Co-57, 111In-111, 133Ba, 201Tl, 99 mTc, 51Cr, 131I, 58Co, 137Cs, 60Co. The total packing density (Vt) was enhanced from 0.589 for S1 glass sample (free with WO3) to 0.605 for S4 glass sample (with highest WO3 =15 mol%). The total energy dissociation (Gt) of the investigated glasses was increased with increasing the WO3 content: from 51.7 (kJ/cm3) for S1 glasses to 52.45 (kJ/cm3) for S4 glasses. All mechanical moduli were improved with increasing the tungsten trioxide concentration in the studied glasses. Poisson's ratios were increased with increasing the WO3 concentration. The trend of linear (LAC) and mass attenuation (MAC) coefficients were followed as: (LAC, MAC) S1 < (LAC, MAC) S2 < (LAC, MAC) S3 < (LAC, MAC) S4. Half (HVL) and tenth (TVL) value layers have the trend as (HVL, TVL) S1 > (HVL, TVL) S2 > (HVL, TVL) S3 > (HVL, TVL) S4. The effective atomic number (Zeff) and electron density (Neff) have the same trend. The lowest transmission Factor (TF) values for all glass specimens were examined at a thickness of 3 cm. Furthermore, the S4 sample displayed the least transmission tendency across all glass thicknesses evaluated. © 2022 The AuthorsPrincess Nourah bint Abdul Rahman University Researchers Supporting Project Number (PNURSP2022R149)

    Promising applicable heterometallic Al2O3/PbO2 nanoparticles in shielding properties

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    Hetrometal oxides of (1 - x)Al2O3/xPbO2(NPs) nanoparticles with different PbO2content(x = 0, 0.3, 0.4, 0.5, 0.6 and 0.7) have been prepared by irradiation method. The NPs powder hasbeen checked by X-ray diffraction (XRD). XRD measurements affirmed the presence of bothpure NPs and nanocomposites of (1 - x)Al2O3/xPbO2NPs with different PbO2contents. Thecalculated structural parameters which using the experimental result of XRD charts to givea complete image of these measurements. Moreover, the results using FLUKA code showedthat the values attenuation coefficient (_m), high effective atomic number (Zeff) and neu-tron shielding parameters increase as the lead dioxide increase in the Al2O3/PbO2samples.While the values of half-value layer (HVL) and mean free path (MFP) decrease with increas-ing PbO2content. The investigated shielding features of the chosen Al2O3/PbO2would beadvantageous for exposure control. © 2020 The Authors.The authors extended their appreciation to the Deanship of Scientific Research at King Khalid University for funding this work through the research group program under grant number R.G.P.2/33/41

    Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

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    Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty

    Population‐based cohort study of outcomes following cholecystectomy for benign gallbladder diseases

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    Background The aim was to describe the management of benign gallbladder disease and identify characteristics associated with all‐cause 30‐day readmissions and complications in a prospective population‐based cohort. Methods Data were collected on consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing all‐cause 30‐day readmissions and complications were analysed by means of multilevel, multivariable logistic regression modelling using a two‐level hierarchical structure with patients (level 1) nested within hospitals (level 2). Results Data were collected on 8909 patients undergoing cholecystectomy from 167 hospitals. Some 1451 cholecystectomies (16·3 per cent) were performed as an emergency, 4165 (46·8 per cent) as elective operations, and 3293 patients (37·0 per cent) had had at least one previous emergency admission, but had surgery on a delayed basis. The readmission and complication rates at 30 days were 7·1 per cent (633 of 8909) and 10·8 per cent (962 of 8909) respectively. Both readmissions and complications were independently associated with increasing ASA fitness grade, duration of surgery, and increasing numbers of emergency admissions with gallbladder disease before cholecystectomy. No identifiable hospital characteristics were linked to readmissions and complications. Conclusion Readmissions and complications following cholecystectomy are common and associated with patient and disease characteristics

    Global overview of the management of acute cholecystitis during the COVID-19 pandemic (CHOLECOVID study)

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    Background: This study provides a global overview of the management of patients with acute cholecystitis during the initial phase of the COVID-19 pandemic. Methods: CHOLECOVID is an international, multicentre, observational comparative study of patients admitted to hospital with acute cholecystitis during the COVID-19 pandemic. Data on management were collected for a 2-month study interval coincident with the WHO declaration of the SARS-CoV-2 pandemic and compared with an equivalent pre-pandemic time interval. Mediation analysis examined the influence of SARS-COV-2 infection on 30-day mortality. Results: This study collected data on 9783 patients with acute cholecystitis admitted to 247 hospitals across the world. The pandemic was associated with reduced availability of surgical workforce and operating facilities globally, a significant shift to worse severity of disease, and increased use of conservative management. There was a reduction (both absolute and proportionate) in the number of patients undergoing cholecystectomy from 3095 patients (56.2 per cent) pre-pandemic to 1998 patients (46.2 per cent) during the pandemic but there was no difference in 30-day all-cause mortality after cholecystectomy comparing the pre-pandemic interval with the pandemic (13 patients (0.4 per cent) pre-pandemic to 13 patients (0.6 per cent) pandemic; P = 0.355). In mediation analysis, an admission with acute cholecystitis during the pandemic was associated with a non-significant increased risk of death (OR 1.29, 95 per cent c.i. 0.93 to 1.79, P = 0.121). Conclusion: CHOLECOVID provides a unique overview of the treatment of patients with cholecystitis across the globe during the first months of the SARS-CoV-2 pandemic. The study highlights the need for system resilience in retention of elective surgical activity. Cholecystectomy was associated with a low risk of mortality and deferral of treatment results in an increase in avoidable morbidity that represents the non-COVID cost of this pandemic
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