152 research outputs found
On the contiguous relations of hypergeometric series
AbstractContiguous relations are a fundamental concept within the theory of hypergeometric series and orthogonal polynomials. Their study goes back to Gauss who gave a list of 15 “fundamental” relations for the F12 hypergeometric series. In this paper we will prove some consequences of contiguous relations of F12
Europium-Doped Tellurite Glasses: The Eu2+ Emission in Tellurite, Adjusting Eu2+ and Eu3+ Emissions toward White Light Emission
Europium-doped magnesium tellurite glasses were prepared using melt quenching techniques and attenuated total reflection (ATR) spectroscopy was used to study the glass structure. The glass transition temperature increased with increasing MgO content. Eu2+ and Eu3+ emissions were studied using photoluminescence spectroscopy (PL). The broad emission of Eu2+ ions centered at approximately 485 nm was found to decrease in intensity with increasing MgO content, while the Eu3+ emission was enhanced. The Eu3+ emission lay within the red orange range and its decay time was found to increase with increasing MgO content. Different excitation wavelengths were used to adjust Eu2+ to Eu3+ emissions to reach white light emission. The white light emission was obtained for the sample with the lowest MgO content under excitation in the near-UV range
On the Molecular Modeling Analyses of Novel HIV-1 Protease Inhibitors Based on Modified Chitosan Dimer
Impact Factors on Subcontractor's Cash Flow Management
Objective: This study aims to define how to maintain and protect the subcontractor firms' cash flow from economic fluctuation through legally sustainable solutions. Methods/Analysis: We conducted a case study in the Eastern Delta Region of Egypt. A questionnaire containing a list of 22 impact factors on subcontractors' cash flow was distributed across multiple subcontractor firms with an 82% response rate. It was designed to explore the factors causing cash flow instability and analyze them using SPSS statistics. Findings: The study finds that inflation, late payments, non-compensation for late payments, poor subcontractor cash flow management, subcontractor firms' inclination to avoid disputes, material price fluctuation, and non-compensation terms, as well as suppliers rejection of payment delays, are the most critical factors of subcontractor cash flow problems. Novelty/Improvement:The study suggests adding three sub-articles to Article 57 in "Tender Law" as legally sustainable solutions to protect and maintain the firm's growth rate from inflation, late payment, and the inclination to avoid disputes. Also, the study recommends that the owner ensure that cash is available before procuring the general contractors, as stated in Egyptian Law 182 of 2018. This study will contribute to establishing a sustainable win-win relationship between subcontractors and general contractors. Doi: 10.28991/CEJ-SP2023-09-08 Full Text: PD
The benefits of parametric design methodology in developing structural solutions for metal furniture
The parametric design methodology is an updated methodology that aims to employ computer design programs (such as Maya and Rhino programs) to find a new and important design pattern that appeared after modernity. It takes care of finding a suitable design for various areas of life, starting with architecture, product design, passing through metal furniture and the smallest details of treatments. Automatically, which saves effort and time, and is unique in its smooth handling of complex blocks and highly complex structural systems in the design of metal furniture to employ these concepts in impressive designs of very complexity adapted to the era, and is characterized by the possibility of obtaining from it a dynamic design as well as sustainable design through the principle of re-employment and the use of materials, making it an almost integrated design. This research aims to clarify the role of the parametric design methodology in upgrading the design of metal furniture. The design thinking of metal furniture has evolved from the traditional approach to the parametric design methodology, and the research found that parametric furniture is now manufactured using algorithmic thinking through certain parameters and variables that are renewable and implementable, where products are made on solid supports with unconventional creative flowing shapes. The parametric design methodology gives each metal furniture design a great level of adaptability to different materials, tools and individual preferences. The parametric design methodology for manufacturing enables manufacturers anywhere to download the design file, and modify the design to suit local materials, available CNC tools, or any specific uses or need
Pelvic exenteration and composite sacral resection in the surgical treatment of locally recurrent rectal cancer
AbstractBackgroundThe incidence of rectal cancer recurrence after surgery is 5–45%. Extended pelvic resection which entails En-bloc resection of the tumor and adjacent involved organs provides the only true possible curative option for patients with locally recurrent rectal cancer.AimTo evaluate the surgical and oncological outcome of such treatment.Patients and methodsBetween 2006 and 2012 a consecutive series of 40 patients with locally recurrent rectal cancer underwent abdominosacral resection (ASR) in 18 patients, total pelvic exenteration with sacral resection in 10 patients and extended pelvic exenteration in 12 patients. Patients with sacral resection were 28, with the level of sacral division at S2–3 interface in 10 patients, at S3–4 in 15 patients and S4–5 in 3 patients.ResultsForty patients, male to female ratio 1.7:1, median age 45years (range 25–65years) underwent extended pelvic resection in the form of pelvic exenteration and abdominosacral resection. Morbidity, re-admission and mortality rates were 55%, 37.5%, and 5%, respectively. Mortality occurred in 2 patients due to perineal flap sepsis and massive myocardial infarction. A R0 and R1 sacral resection were achieved in 62.5% and 37.5%, respectively. The 5-year overall survival rate was 22.6% and the 4-year recurrence free survival was 31.8%.ConclusionExtended pelvic resection as pelvic exenteration and sacral resection for locally recurrent rectal cancer are effective procedures with tolerable mortality rate and acceptable outcome. The associated morbidity remains high and deserves vigilant follow up
GENETIC RELATEDNESS AMONG MAIZE INBRED LINES BASED ON ISSR MARKERS AND ITS ASSOCIATION WITH HETEROSIS AND HYBRID PERFORMANCE
The objectives of the present study were to measure the genetic diversity among eight inbred lines of maize using ISSR markers and the correlation coefficients between genetic diversity and each of heterosis and mean performance of hybrids for grain yield. Ten ISSR primers were used in the detection of polymorphism of the eight inbred lines in a laboratorial experiment. Heterosis and mean performance of grain yield/ha in their F1 diallel crosses were measured in a 2-year field experiment using a randomized complete blocks design with three replications. Based on ISSR markers, the genetic similarity coefficients among the eight maize inbred lines ranged from 0.798 (between L17 and IL53) to 0.943 (between IL80 and IL84) with an average of 0.869. Unique bands associated with maize inbred lines were identified. The results revealed that the genetic diversity among the inbred lines based on ISSR markers showed a significant, and negative relationship with mid-parent heterosis and mean performance of grain yield/ha. Further, intensive investigation of a large set of maize inbred lines from diverse populations using a large number of ISSR primers is required for proper understanding of genetic diversity of maize crop. Findings will be valuable for maize breeder, to practice effective selection of parental inbred lines for obtaining maximum heterosis and high mean grain yield/ha in their hybrids
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