Theoretical Study of Solvent Effects on 1,3- Dipolar Cycloaddition Reaction

في هذه الدراسة تم اجراء التحليل الانحداري لثابت التفاعل 15 مع معاملات المذيبات لمجموعتين من تفاعلات الاضافة الحلقي ال1و3-ثنائي القطب. الاولى هي تفاعل الازوميثاين(1)  مع السايكلواوكتاين (2),و اليينامين(3), و ثنائي مثيل اسيتيلين كاربوكسيليت(4). والمجموعة الثانية هي تفاعل النيترونات 5و6 مع الدايبولاروفيل 7 . كما تم اجراء الحسابات الشبه تجريبية للمتفاعلات حيث رسمت القيم الكمية الناتجة ضد معاملات التفاعل وضد معاملات المذيبات. وتم الحصول على نتائج متباينة الجودة لهذه التفاعلات. واجري تحليل رج الانحداري لغرض تصحيح الشذوذ الخطي للنماذج ذات المعاملات المتعددة. الغرض من هذه الدراسة هو الحصول على نموذج او نماذج والتي بواسطتها يمكن التنبؤ بالظروف المثالية للتفاعل قبل العمل المختبري.In the present study the regression analysis of the rate constant k 15with solvent parameters, for two sets of 1,3-dipolarcycloaddition reactions were done. The first was the reaction azomethine 1 with cyclooctyne 2, ynamine 3 and dimethyl acetylenecarboxylate (4) in different nonprotic solvents. The second were the reactions of the nitrones 5 and 6 with dipolarophile 7. Semiempirical calculations (PM3) were done for the reactants. The resulting quantum descriptors HOMO-LUMO and the transition state quantum descriptors (LUMOdipolarophile - HOMOdipole (HdL) and LUMOdipole – HOMOdipolarophile (LdH)) were plotted against solvent parameters, in order to obtain predictive computational models. Good to excellent correlations were obtained for these reactions. The multiparameteric models obtained were corrected for collinearity   by using Ridge regression

Strengthening of Recycled Aggregate Concrete Slender Column with CFRP

This piece provides an overview of an experimental program that tests the structural performance of slender recycled aggregate RAC columns that are externally restrained by carbon fiber reinforced polymer (CFRP composite system). To demonstrate that the CFRP strengthening system is one of the recommended effective techniques for making up for the reduction in load-carrying capacity caused by the use of 100% RCA in combination with the slenderness of column specimens, eight slender circular RC columns were modeled and tested. To more accurately predict the structural features of the RC thin column (the ultimate carrying weight, first cracking load, load-displacement curve, and load-strain response), the findings from experiments have been analyzed and monitored. The findings indicated that the type of transverse reinforcement and the amount of external strengthening impact the degree of improvement in column performance. The strength for the tied RC columns with 100% RCA confined by (25, 50, and 100) % CFRP increased by 5.5, 44.97, and 112.85%, respectively, compared to control columns with no CFRP confinement. Similar strength improvements are seen in spirally RC columns with 100% RCA and the same external confinement coverage ratio: 10.32, 42.81, and 113.51%

Behavior of Recycled Aggregate Concrete Slender Column under Concentric Axial Loading

This investigation investigates the structural behavior of slender reinforced concrete RC containing different RCA replacement portions in addition to the slenderness effect. To perform this, eight (8) slender RC columns with two main types of transverse reinforcement (ties and spiral reinforcement) and three recycled coarse aggregate RCA replacement percentages (25, 50, and 100%) were modeled and subjected to axial concentric loading. The gathered experimental results are monitored and analyzed to better estimate the structural characteristics of the RC slender column (The ultimate carrying load, first cracking load, load-displacement curve, and load-strain response). The results showed that replacing NCA with (25, 50, and 100%) of RCA reduced the ultimate capacity of tied RC columns by (13.41, 14.07, and 23.33%), respectively, and reduced their first cracking load values by (19.64, 15.96, 22.50%), respectively. The reduction in ultimate load capacity and the first cracking load were (4.10, 17.33, 22.63%) and (12.26, 23.15, 25.00%) for spirally RC columns, respectively. Spiral transverse reinforcement slightly increases the carrying load capacity compared to tie reinforcement. It delays the fast propagation of the first cracking load, furthers the effect of spiral reinforcement in improving the deformation capacity, reducing the longitudinal and lateral mid-height strains, and developing the flexural stiffness of the load-displacement curve

Voltammetric determination of Hg²⁺, Zn²⁺, and Pb²⁺ ions using a PEDOT/NTA-modified electrode

[Image: see text] A novel electrochemical sensor for determining trace levels of Hg(2+), Pb(2+), and Zn(2+) ions in water using square wave voltammetry (SWV) is reported. The sensor is based on a platinum electrode (Pt) modified by poly(3,4-ethylenedioxythiophene) and N(α),N(α)-bis-(carboxymethyl)-l-lysine hydrate (NTA lysine) PEDOT/NTA. The modified electrode surface (PEDOT/NTA) was prepared via the introduction of the lysine-NTA group to a PEDOT/N-hydroxyphthalimide NHP electrode. The (PEDOT/NTA) was characterized via cyclic voltammetry (CV), Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). The effects of scan rates on the electrochemical properties of the polymer electrode were also investigated. The electrochemical results were used to estimate the coverage of the electrode polymer surface and its electrostability in background electrolyte solutions. Several analytical parameters, such as polymer film thickness, metal deposition time, and pH of the electrolyte, were examined. Linear responses to Hg(2+), Pb(2+), and Zn(2+) ions in the concentration range of 5–100 μg L(–1) were obtained. The limits of detection (LODs) for the determination of Hg(2+), Pb(2+), and Zn(2+) ions were 1.73, 2.33, and 1.99 μg L(–1), respectively. These promising results revealed that modified PEDOT/NTA films might well represent an important addition to existing electrochemical sensor technologies

Transient MHD Double-Diffusive Natural Convection over a Vertical Surface Embedded in a Non-Darcy Porous Medium

The problem of transient, laminar, MHD double-diffusive free convection over a permeable vertical plate embedded in Darcy and non-Darcy porous medium is numerically investigated. Nonsimilarity solutions are obtained for constant wall temperature and concentration with a specified power law of mass flux parameter. The effects of the magnetic parameter, the inertial coefficient, Lewis number, the buoyancy ratio, and the lateral mass flux on heat and mass transfer coefficients are presented and discussed

Antigenic Detection of Salmonella Infection among Pediatric Patients with Acute Gastroenteritis

Background: Diarrheal diseases are one of the social problems in developing countries. The pathogens commonly associated with childhood diarrhea are Salmonella, Clostridium difficile, Shigella, Yersinia and Escherichia coli but the highest attack rate for salmonellosis in infancy. Objective: The aim of the study was to evaluate the presence of Salmonella antigen in acute gastroenteritis in children admitted to a pediatric hospital. Material and Methods: The study was performed on freshly collected stool samples among 94 acute diarrheal children below two years admitted to AL-Khadymia and AL-Elweya pediatric hospitals from May 2015 to January 2016. A questionnaire was completed for each patient’s name, age, gender, clinical data like fever, nausea, vomiting, and abdominal pain. The criteria included hemorrhagic fresh stool sample in addition to containing parasite agent. Fresh stool samples were tested by immunochromatographic assay for antigenic detection of Salmonella. Results: Salmonella antigen identified in five stool samples one for male and four for females. All pediatric patients show fever, vomiting and abdominal pain, while the stool consistency distributed to 75.5% watery and 24.5% loosely. Stool samples show 69.1% with blood and 39.9% without blood, 16.9% with pus and 83.1% without pus, 83% with mucous and 17% without mucous. Four cases with giardiasis and 24 cases with entamebiasis and 14 cases with cyst of E. histolytica or G. lamblia in addition to absence the parasites ova in all stool samples. Conclusion: Salmonella antigen present in five stool samples, all the patients show vomiting, fever, abdominal pain, 65 cases with blood in comparison with, 29 without blood 15 cases with pus in comparison with 79 without pus. 78 cases with mucous in comparison with, 16 without mucous, four cases with goddesses and 24 cases with entamebiasis, 14 cases with cyst of E. histolytica or G. lamblia in addition to absence the parasites ova in all stool samples

The burden of unintentional drowning : global, regional and national estimates of mortality from the Global Burden of Disease 2017 Study

Background Drowning is a leading cause of injury-related mortality globally. Unintentional drowning (International Classification of Diseases (ICD) 10 codes W65-74 and ICD9 E910) is one of the 30 mutually exclusive and collectively exhaustive causes of injury-related mortality in the Global Burden of Disease (GBD) study. This study's objective is to describe unintentional drowning using GBD estimates from 1990 to 2017. Methods Unintentional drowning from GBD 2017 was estimated for cause-specific mortality and years of life lost (YLLs), age, sex, country, region, Socio-demographic Index (SDI) quintile, and trends from 1990 to 2017. GBD 2017 used standard GBD methods for estimating mortality from drowning. Results Globally, unintentional drowning mortality decreased by 44.5% between 1990 and 2017, from 531 956 (uncertainty interval (UI): 484 107 to 572 854) to 295 210 (284 493 to 306 187) deaths. Global age-standardised mortality rates decreased 57.4%, from 9.3 (8.5 to 10.0) in 1990 to 4.0 (3.8 to 4.1) per 100 000 per annum in 2017. Unintentional drowning-associated mortality was generally higher in children, males and in low-SDI to middle-SDI countries. China, India, Pakistan and Bangladesh accounted for 51.2% of all drowning deaths in 2017. Oceania was the region with the highest rate of age-standardised YLLs in 2017, with 45 434 (40 850 to 50 539) YLLs per 100 000 across both sexes. Conclusions There has been a decline in global drowning rates. This study shows that the decline was not consistent across countries. The results reinforce the need for continued and improved policy, prevention and research efforts, with a focus on low- and middle-income countries.Peer reviewe

Global injury morbidity and mortality from 1990 to 2017 : results from the Global Burden of Disease Study 2017

Correction:Background Past research in population health trends has shown that injuries form a substantial burden of population health loss. Regular updates to injury burden assessments are critical. We report Global Burden of Disease (GBD) 2017 Study estimates on morbidity and mortality for all injuries. Methods We reviewed results for injuries from the GBD 2017 study. GBD 2017 measured injury-specific mortality and years of life lost (YLLs) using the Cause of Death Ensemble model. To measure non-fatal injuries, GBD 2017 modelled injury-specific incidence and converted this to prevalence and years lived with disability (YLDs). YLLs and YLDs were summed to calculate disability-adjusted life years (DALYs). Findings In 1990, there were 4 260 493 (4 085 700 to 4 396 138) injury deaths, which increased to 4 484 722 (4 332 010 to 4 585 554) deaths in 2017, while age-standardised mortality decreased from 1079 (1073 to 1086) to 738 (730 to 745) per 100 000. In 1990, there were 354 064 302 (95% uncertainty interval: 338 174 876 to 371 610 802) new cases of injury globally, which increased to 520 710 288 (493 430 247 to 547 988 635) new cases in 2017. During this time, age-standardised incidence decreased non-significantly from 6824 (6534 to 7147) to 6763 (6412 to 7118) per 100 000. Between 1990 and 2017, age-standardised DALYs decreased from 4947 (4655 to 5233) per 100 000 to 3267 (3058 to 3505). Interpretation Injuries are an important cause of health loss globally, though mortality has declined between 1990 and 2017. Future research in injury burden should focus on prevention in high-burden populations, improving data collection and ensuring access to medical care.Peer reviewe