Effect of Pulse Shapes on the Weldability of High Conductivity Copper ‎C101 by Nd-YAG Laser

تم لحام وصلات تراكب مماثلة من صفائح رقيقة من النحاس النقي C101 باستخدام اللحام بالليزر النبضي. تم دراسة تأثير معاملات اللحام بالليزر على الخواص الميكانيكية. أظهرت النتائج التجريبية أنه يمكن الحصول على وصلات خالية من عيوب الصوت من وصلات نحاسية - نحاسية مماثلة حيث يحدث الكسر بعيدًا عن خط اللحام. يقترح العمل الحالي تحسين التحكم في التصميم لثلاثة أشكال مختلفة للنبض؛ مستطيلة (عادية)، منحدرة لأسفل ومعدلة وتستخدم في لحام ست عينات نحاسية مختلفة لتحقيق أقصى قوة شد وقص للمفاصل. أوضحت النتائج أن شكل النبضة المعدلة هو الأمثل في اختبار شد القص. كان لشكل النبضة المنحدرة تأثير أقل أهمية على قوة المفصل النحاسي عند مقارنته بشكل النبضة المستطيلة. تم الحصول على العلاقة بين معلمات الإدخال والإخراج من خلال استخدام برنامج Minitab، وتم استخدام برنامج Matlab للوصول إلى الحل الأمثل. أظهرت الخوارزمية الجينية أن المقدار الأمثل الذي تم تحقيقه لقوة القص كان 77.9 ميجا باسكال، وكانت معلمات الإدخال المثلى هي طاقة النبضة البالغة 39 جول وعرض النبضة 8.5 وتردد 10 هرتز والسرعة الخطية 160 ملم / دقيقة. Similar lap joints of pure copper C101 thin sheets were welded using pulsed laser welding. The effect of laser welding parameters on mechanical properties was investigated. The experimental results revealed that sound defect-free joints could be obtained from similar copper-copper joints where the fracture occurs away from the weld line. The present work proposes improved design control for three different pulse shapes; rectangular (normal), ramped-down and modulated which are used to weld six different copper samples to achieve the optimum tensile-shear strength of the joints. Results showed that modulated pulse shape has the optimum in the shear-tensile test. Ramped-down pulse shape had a less significant effect on the strength of the copper joint when compared with the rectangular pulse shape.  The relationship between the input and output parameters was obtained by employing Minitab software, and the Matlab software was used in order to reach the optimum solution. The genetic algorithm showed that the optimum magnitude achieved for the shear strength was 77.9 MPa, and the optimum input parameters were pulse energy of 39J, the pulse width of 8.5, frequency of 10Hz and linear speed of 160mm/min.&nbsp

Laparoscopic Management of Intra-Abdominal Testis: 5-Year Single-Centre Experience—A Retrospective Descriptive Study

Background. Undescended testis is one of the most common urological problems in children, affecting about 1% of boys at age of 1 year. Of these, about 20% have a nonpalpable testis with a very high probability that the testis is absent. This may have a significant impact on the possibility of malignancy in these testes, as well as on the later fertility of these subjects. Methods. We retrospectively analyzed the demographic and clinical findings, as well as immediate and 6-month outcomes, in 91 patients diagnosed with impalpable undescended testes between January 2006 and December 2010. Results. Of the 91 patients, 9 had bilateral and 82 had unilateral impalpable testes. All 100 testes were managed laparoscopically. The largest group of intra-abdominal testes in this series, 42 testes, was entering the internal ring; in these, laparoscopic exploration and standard open orchiopexy resulted in a 66% success rate. The total success rate was 63.3%. Conclusion. Laparoscopy is extremely useful in both the diagnosis and treatment of impalpable testes. Objectively measured mobility of the testis towards the contralateral internal inguinal ring is an excellent intraoperative indicator for type of orchiopexy. Standardization of management may increase the success rate of orchiopexy

Genetic and morphological identification of some crabs from the Gulf of Suez, Northern Red Sea, Egypt

AbstractMost crab species inhabiting the Red Sea have not been characterized morphologically and genetically. In the current work, five different crab species were collected from the northern part of the Egyptian Red Sea. They were morphologically identified through description of colors, dentations of the carapace and shapes of chelipeds and pereiopods. They were also genetically characterized by the partial sequencing of the barcode region in the mitochondrial cytochrome oxidase subunit I (COI) gene, which is known to be hypervariable among different crab species. Morphological and genetic characterization identified the crab species as: Charybdis (Charybdis) hellerii (A. Milne-Edwards, 1867), Charybdis (Charybdis) natator (Herbst, 1794), Portunus (Portunus) pelagicus (Linnaeus, 1758), Liocarcinus corrugatus (Pennant, 1777), and Atergatis roseus (Rüppell, 1830). This is the first record of L. corrugatus in the Egyptian Red Sea, despite being previously recorded in the Indian and Atlantic Ocean as well as in the Mediterranean Sea. DNA barcoding with precise morphological identification was effective in characterizing the crab species collected from the Egyptian Red Sea water

Endozoochory by goats of two invasive weeds with contrasted propagule traits

Invasive plants have very important ecological and socioeconomic impacts. Producing and dispersing many viable seeds are key plant functional traits for invaders. Ungulate grazing plays an important role in the endozoochorous seed dispersal within grasslands and rangelands. Grazing can be applied as a practical and economical control method for plant invasions. We analyzed the effects of seed passage through the goat digestive system on the germination and viability for Sorghum halepense and Malva parviflora, common invasive species with contrasted propagules and seed traits. Both studied species produced seeds able to survive, in a small percentages (c. 0.80-1.70%), after being eaten by goats. Most of the seeds (c. 40-55%) of both species were retrieved between 24-48 h after ingestion. Goat passage provoked a decrease (> 60%) in the germination percentage and seed viability of S. halepense that was higher with longer gut retention times. In M. parviflora, the goat gut passage did not break its primary physical dormancy, since no retrieved seed germinated with similar viability as the uneaten seeds (c. 90%). In view of our results, goat grazing can be applied as a useful method to control S. halepense and M. parviflora invasions. Goats should be kept in corrals for at least 4 days after grazing to prevent transferring viable seeds to uninfected areas.Deanship of Scientific Research King Khalid University R.G.P.1/210/4

The effects of the ambient liquid medium on the ablation efficiency, size and stability of silver nanoparticles prepared by pulse laser ablation in liquid technique

Silver (Ag) nanoparticles (NPs) were synthesized by pulsed laser (Nd:YAG, 1064 nm) ablation of individual target in various solutions. The influence of deionized water (DIW), ethanol and Polyvinylpyrrolidone (PVP) as ambient medium on the fundamental aspects such as ablation efficiency, particle size and stability of Ag NPs was studied. UV-vis spectrophotometer and transmission electron microscopy (TEM) were used to study the optical characterization and morphological analysis of all the synthesized samples, respectively. Preparation in DIW was carried out as a reference sample. The experiments demonstrated that ablation efficiency and stability of NPs in ethanol medium are lowest than those prepared in PVP medium and the reference sample. PVP medium led to higher stability, lower ablation efficiency and finer average particle size compared to reference sample

Genotypic and Phenotypic Structure of the Population of Phytophthora infestans in Egypt Revealed the Presence of European Genotypes

Late blight disease of potato and tomato, caused by Phytophthora infestans, results in serious losses to Egyptian and global potato and tomato production. To understand the structure and dynamics of the Egyptian population of P. infestans, 205 isolates were collected from potato and tomato plants during three growing seasons in 2010–2012. The characterization was achieved by mating-type assay, metalaxyl sensitivity assay, and virulence pattern. Additionally, genotyping of 85 Egyptian isolates and 15 reference UK isolates was performed using 12 highly informative microsatellite (SSR) markers David E. L. Cooke and five effector (RxLR) genes. Mating-type testing showed that 58% (118 of 205) of the isolates belonged to mating type A1, 35% (71 isolates) to mating type A2, and the rest 8% (16 isolates) were self-fertile. The phenotype of metalaxyl response was represented as 45% resistant, 43% sensitive, and 12% as intermediate. Structure analysis grouped the 85 identified genotypes into two main clonal lineages. The first clonal lineage comprised 21 isolates belonging to A2 mating type and 8 self-fertile isolates. This clonal lineage was identified as Blue_13 or EU_13_A2. The second main clonal lineage comprised 55 isolates and was identified as EU_23_A1. A single isolate with a novel SSR genotype that formed a distinct genetic grouping was also identified. The effector sequencing showed good correspondence with the virulence data and highlighted differences in the presence and absence of loci as well as nucleotide polymorphism that affect gene function. This study indicated a changing population of P. infestans in Egypt and discusses the findings in the context of late blight management

Effect of bio-degradation on the physical properties of Palm Oil Mill Effluent (Pome) using mixed culture of fungi

This study investigated the effects of biodegradation by the mixed culture of fungi(Pithomyces sacchari and Pestalotiopsis maculans) on selected physical properties of palm oil mill efluent(POME). Mixed culture innoculum(4% v/v) was added to autoclaved and raw POME samples, which were subjected to biodegradation at 120 rpm and 35 degree Celsius ofr six days. The pH, electrical conductivity, total dissolve solids and biosolids of the digested samples were quantified at 24 h intervals. These parameters for the auoclaved sample, at the end of the digestion period, were 6.88, 4.38mS/cm, 2.28g/L, respectively. The kinetics studies of the degradation of Pome, based on the concentration of the biosolids were also investigated. The kinetic studies show that the degradation of the raw POME sample best fits the zero order kinetic model(R^2=0.96) while the degradation of the autoclaved POME samples best fits the first order kinetic model(R^2=0.83). However, the digested POME may require Further treatment in order to meet standard suitable for discharge into the water body

Casirivimab and imdevimab in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Background: Casirivimab and imdevimab are non-competing monoclonal antibodies that bind to two different sites on the receptor binding domain of the SARS-CoV-2 spike glycoprotein, blocking viral entry into host cells. We aimed to evaluate the efficacy and safety of casirivimab and imdevimab administered in combination in patients admitted to hospital with COVID-19. Methods: RECOVERY is a randomised, controlled, open-label platform trial comparing several possible treatments with usual care in patients admitted to hospital with COVID-19. 127 UK hospitals took part in the evaluation of casirivimab and imdevimab. Eligible participants were any patients aged at least 12 years admitted to hospital with clinically suspected or laboratory-confirmed SARS-CoV-2 infection. Participants were randomly assigned (1:1) to either usual standard of care alone or usual care plus casirivimab 4 g and imdevimab 4 g administered together in a single intravenous infusion. Investigators and data assessors were masked to analyses of the outcome data during the trial. The primary outcome was 28-day all-cause mortality assessed by intention to treat, first only in patients without detectable antibodies to SARS-CoV-2 infection at randomisation (ie, those who were seronegative) and then in the overall population. Safety was assessed in all participants who received casirivimab and imdevimab. The trial is registered with ISRCTN (50189673) and ClinicalTrials.gov (NCT04381936). Findings: Between Sept 18, 2020, and May 22, 2021, 9785 patients enrolled in RECOVERY were eligible for casirivimab and imdevimab, of which 4839 were randomly assigned to casirivimab and imdevimab plus usual care and 4946 to usual care alone. 3153 (32%) of 9785 patients were seronegative, 5272 (54%) were seropositive, and 1360 (14%) had unknown baseline antibody status. 812 (8%) patients were known to have received at least one dose of a SARS-CoV-2 vaccine. In the primary efficacy population of seronegative patients, 396 (24%) of 1633 patients allocated to casirivimab and imdevimab versus 452 (30%) of 1520 patients allocated to usual care died within 28 days (rate ratio [RR] 0·79, 95% CI 0·69–0·91; p=0·0009). In an analysis of all randomly assigned patients (regardless of baseline antibody status), 943 (19%) of 4839 patients allocated to casirivimab and imdevimab versus 1029 (21%) of 4946 patients allocated to usual care died within 28 days (RR 0·94, 95% CI 0·86–1·02; p=0·14). The proportional effect of casirivimab and imdevimab on mortality differed significantly between seropositive and seronegative patients (p value for heterogeneity=0·002). There were no deaths attributed to the treatment, or meaningful between-group differences in the pre-specified safety outcomes of cause-specific mortality, cardiac arrhythmia, thrombosis, or major bleeding events. Serious adverse reactions reported in seven (<1%) participants were believed by the local investigator to be related to treatment with casirivimab and imdevimab. Interpretation: In patients admitted to hospital with COVID-19, the monoclonal antibody combination of casirivimab and imdevimab reduced 28-day mortality in patients who were seronegative (and therefore had not mounted their own humoral immune response) at baseline but not in those who were seropositive at baseline. Funding: UK Research and Innovation (Medical Research Council) and National Institute of Health Research

Global burden of respiratory infections associated with seasonal influenza in children under 5 years in 2018: A systematic review and modelling study

Background: Seasonal influenza virus is a common cause of acute lower respiratory infection (ALRI) in young children. In 2008, we estimated that 20 million influenza-virus-associated ALRI and 1 million influenza-virus-associated severe ALRI occurred in children under 5 years globally. Despite this substantial burden, only a few low-income and middle-income countries have adopted routine influenza vaccination policies for children and, where present, these have achieved only low or unknown levels of vaccine uptake. Moreover, the influenza burden might have changed due to the emergence and circulation of influenza A/H1N1pdm09. We aimed to incorporate new data to update estimates of the global number of cases, hospital admissions, and mortality from influenza-virus-associated respiratory infections in children under 5 years in 2018.Methods: We estimated the regional and global burden of influenza-associated respiratory infections in children under 5 years from a systematic review of 100 studies published between Jan 1, 1995, and Dec 31, 2018, and a further 57 high-quality unpublished studies. We adapted the Newcastle-Ottawa Scale to assess the risk of bias. We estimated incidence and hospitalisation rates of influenza-virus-associated respiratory infections by severity, case ascertainment, region, and age. We estimated in-hospital deaths from influenza virus ALRI by combining hospital admissions and in-hospital case-fatality ratios of influenza virus ALRI. We estimated the upper bound of influenza virus-associated ALRI deaths based on the number of in-hospital deaths, US paediatric influenza-associated death data, and population-based childhood all-cause pneumonia mortality data in six sites in low-income and lower-middle-income countries.Findings: In 2018, among children under 5 years globally, there were an estimated 109·5 million influenza virus episodes (uncertainty range [UR] 63·1-190·6), 10·1 million influenza-virus-associated ALRI cases (6·8-15·1); 870 000 influenza-virus-associated ALRI hospital admissions (543 000-1 415 000), 15 300 in-hospital deaths (5800-43 800), and up to 34 800 (13 200-97 200) overall influenza-virus-associated ALRI deaths. Influenza virus accounted for 7% of ALRI cases, 5% of ALRI hospital admissions, and 4% of ALRI deaths in children under 5 years. About 23% of the hospital admissions and 36% of the in-hospital deaths were in infants under 6 months. About 82% of the in-hospital deaths occurred in low-income and lower-middle-income countries.Interpretation: A large proportion of the influenza-associated burden occurs among young infants and in low-income and lower middle-income countries. Our findings provide new and important evidence for maternal and paediatric influenza immunisation, and should inform future immunisation policy particularly in low-income and middle-income countries.Funding: WHO; Bill & Melinda Gates Foundation