Effect Of Crumb Rubber Incorporation On The Behaviour Of Concrete Beam Subjected To Impact Load

It is well known that concrete containing crumb rubber would enhance the elastic properties of concrete as well as ability to absorb energy. However, the actual flexural energy under impact load is still questionable and debatable. Moreover, the behavior of hybrid (rubberized top-plain bottom) concrete structures under impact or static load conditions are yet to be investigated. In this study, experimental and nonlinear dynamic analysis of rubberized concrete under impact load was investigated. Rubberized concrete samples were prepared by partial substitution (5%, 10% and 20 % replacements by volume) of sand or cement by two size of crumb or powder rubber respectively, and tested under impact three-point bending load, as well as static load. Three types of specimens namely, plain concrete, rubberized concrete, and double layer concrete were loaded to failure in a drop-weight impact machine by subjecting to 20N weight from a height of 300mm, and another three similar specimens were used for the static load test. In both tests, the load-deflection and fracture energy of each specimen were investigated. Finite-element simulations were also performed to study the dynamic behaviours of the samples, by using LUSAS V.14 software. The concrete beam was modeled to be built with eight node hexahedron elements and elasto-plastic material was used to model both plain and rubberized concrete structures. Explicit nonlinear dynamic scheme was used to determine the deflection increments for each time step.In general the result was noticed that, the impact loads increased with the increase in the percentage of rubber

Effect of compost and urea nitrogen on growth and yield of sweet pepper (Capsicum annuum L.) and on some properties of the Gezira soil

       Compost is stable humus like product resulting from biological decomposition of organic matter under controlled conditions. The objective of this study was to investigate the combined effect of compost with urea nitrogen on some soil properties, growth and yield of sweet pepper. This study comprised a number of experimentations conducted over two consecutive seasons (2009/10-2010/11) at the Experimental Farm of the Faculty of Agricultural Sciences, University of Gezira and laboratories of CIRAD in France. Compost was applied at 0, 10 and 20 t ha-1 combined with N at 0, 43 and 86 kg ha-1 in the form of urea. The results showed that application of compost alone or in combination with urea nitrogen improved soil properties and hence growth and yield of sweet pepper. Improvement of those parameters was more pronounced when the urea and compost were combined, especially at the higher rates. Combination of urea and compost presumably improved availability of nitrogen from the organic source to sweet pepper and, therefore, positively affected growth and yield of the crop. The extent of improvement was less when urea nitrogen and organic manures were applied in the same season. Hence, it could be recommended to fertilize sweet pepper with compost and urea at the rate of 86 kg N/ ha

Evolution from 4f-electron antiferromagnetic to ferromagnetic order in the CeCu(Ge1-xSnx) alloy series (0≤x≤1)

We report the evolution from ferromagnetic (FM) to antiferromagnetic (AFM) state in CeCu(Ge1-xSnx) investigated by means of magnetic and heat capacity measurements. X-ray diffraction studies for all compositions indicate the ZrBeSi - type hexagonal crystal structure with space group P63/mmc (No. 194). The magnetic susceptibility, x(T) at high temperature follows the Curie - Weiss relation with an effective magnetic moment close to the value of 2.54 µB expected for free Ce3+ - ion. At low temperatures, x(T) data indicate AFM transition for alloys in the concentration range 0.7≤x≤1 and FM for x≤0.6. The magnetization, M(µ0H) of samples exhibiting AFM behaviour shows metamagnetic transition at low magnetic fields with some irreversibility in the process of increasing and decreasing magnetic field. In turn, M(µ0H) of samples exhibiting FM behaviour shows saturation in high magnetic fields. Heat capacity, Cp(T) data confirm the AFM and FM transitions observed in magnetic measurements. An additional anomaly below TC and TN is observed in Cp(T)/T, which likely arises from spin reorientation or rearrangement in FM or AFM structure. Below in FM region, Cp(T) can be well described assuming spin-waves excitations with an energy gap ∆C.Scopu

Clinical Staging and Flowcytomteric CD38 and Zap 70 Prognostic Indicators in Sudanese Patients with Chronic Lymphocytic Leukemia

Background: The clinical course of chronic lymphocytic leukemia is highly variable. The determination of ZAP70 and CD38 is increasingly utilized as prognostic factor for chronic lymphocytic leukemia. The aim of conducting this study was to investigate the frequency of CD38 and ZAP70 expression among Sudanese Chronic lymphocytic leukemia (CLL) patients and to relate them to the Binet and Rai clinical staging systems. Method: A total of 93 patients (mean age; 62.29 ± 11.68, sd) were enrolled in this cross-sectional study. CD38 and ZAP70 expression levels were measured with four color flowcytometry using the cut-off values of 20% for ZAP70 and 30% for CD38 expression. Staging was assessed by using clinical examination and CBC for all patients. Data were analyzed using the Statistical Package for Social science for Windows (SPSS), version 22. Results: There were 93 CLL patients and the median age of the group was 63 years (36–95 years). About 71% of the patients presented with lymphadenopathy, 53.8% with splenomegaly, 73.1% with anemia, and 45.2% with thrombocytopenia. There was higher frequency of Binet stage C and Rai stage IV (62 [66.6%] patients and 34 [36.5%] patients, respectively). In addition, CD38 and ZAP70 showed higher frequency among Binet and Rai advance stages. ZAP70 and CD38 positivity were detected in 21 patients (22.6%) and 31 patients (33.3%), respectively. There was no statistically significant association between ZAP70 and CD38 and clinical staging systems (P-value > 0.05). Conclusion: No significant association was observed between Flowcytometric (CD38 and Zap70) Prognostic Indicators and clinical staging systems. Keywords: chronic lymphocytic Leukemia, Flowcytometry, ZAP70, CD38, clinical staging system

Preparation and characterization of quinoxaline-pyrene-based conjugated copolymers for organic photovoltaic devices

In this study, two novel conjugated polymers, poly(4,5,9,10-tetrakis((2-ethylhexyl)oxy]pyrene-alt-2,3-bis(3-(octyloxy)phenyl)-5,8-di(2-thienyl)-6,7-difluoroquinoxaline) (PPyQxff) and poly(4,5,9,10-tetrakis((2-ethylhexyl)oxy)pyren-alt-2,3-bis(3-(octyloxy)phenyl)-5,8-di(2-thienyl)quinoxaline) (PPyQx), consisting of quinoxaline units with and without fluorine substituents, as electron-accepting moieties and pyrene flanked with dithienyl units as electron-donating moieties were prepared via Stille polymerization reactions for use as electron donor materials in bulk heterojunction (BHJ) solar cells. PPyQxff and PPyQx were characterized by X-ray powder diffraction (XRD), gel permeation chromatography (GPC), thermogravimetric analysis (TGA), cyclic voltammetry (CV), UV−VIS absorption, and nuclear magnetic resonance (NMR) spectroscopy. PPyQxff and PPyQx revealed excellent solution processability in common organic solvents. PPyQxff and PPyQx presented decomposition temperatures above 300 °C. The inclusion of F atoms to the quinoxaline moiety made a slight reduction in the highest occupied molecular orbital (HOMO) level, relative to the unfluorinated polymer, but had no impact on the lowest unoccupied molecular orbital (LUMO) level. PPyQxff and PPyQx exhibited similar physical properties with strong and broad absorbance from 400 to 700 nm and an optical band-gap energy of 1.77 eV. The X-ray powder diffraction study indicated that PPyQxff possessed a reduced π–π stacking distance relative to PPyQx

Development and Evaluation of an Expert System for Diagnosing Tinnitus Disease

Tinnitus is a common condition characterized by the perception of sound in the absence of an external source, with potential negative physical and psychological impacts. Accurate and efficient diagnosis of tinnitus is crucial for appropriate treatment and management. Traditional diagnostic methods have limitations in terms of time, cost, and accuracy. To address these challenges, expert systems have emerged as a promising tool for tinnitus diagnosis. This paper explores the application of expert systems in tinnitus diagnosis, highlighting their potential to improve accuracy and efficiency. By incorporating a knowledge base and rule-based decision-making, expert systems can provide valuable insights for accurate diagnosis and appropriate management of tinnitus. Further research and development in this area can enhance the clinical assessment and treatment of tinnitus, ultimately improving the quality of life for affected individuals

Development and Evaluation of an Expert System for Diagnosing Kidney Diseases

This research paper presents the development and evaluation of an expert system for diagnosing kidney diseases. The expert system utilizes a decision-making tree approach and is implemented using the CLIPS and Delphi frameworks. The system's accuracy in diagnosing kidney diseases and user satisfaction were evaluated. The results demonstrate the effectiveness of the expert system in providing accurate diagnoses and high user satisfactio

ZAP-70 Expression in B-Chronic Lymphocytic Leukemia in Sudanese Patients

Background: Chronic lymphocytic leukemia is the most common form of leukemia in adults. The prognostic impact of ZAP-70 in CLL has been reported in several studies. The aim of conducting this study was to investigate the prevalence of ZAP-70 in Sudanese patients with chronic lymphocytic leukemia attending Khartoum Oncology Hospital.Materials and Methods: A total of 93 newly diagnosed patients with chronic lymphocytic leukemia were enrolled in this study. Lymphadenopathy and organomegaly were assessed in all participants using clinical examination, chest radiography, and abdominal ultrasound. Full blood count was carried out by an automated hematology analyzer. ZAP-70 was evaluated using flowcytometry on peripheral blood samples. ZAP-70 was defined as positive expression at a cutoff level of 20%. Results: There were 63 (67.7%) males and 30 (32.3%) females and the median age of the group was 63 years; 68 patients (73.1%) were presented with anemia and 66(70.9%) had lymphadenopath;y. Majority of our patients 35 (37.6%) were in Rai stage IV. ZAP-70 positivity was detected in 21 patients (22.6%). There was no statistically significant association of ZAP-70 with age, sex, lymphadenopathy, organomegaly, hemoglobin concentration, total white blood cell count, platelet count and Rai staging system (p-value > 0.05). Conclusion: Only 21 patients (22.6%) were ZAP-70 positive. There was no association between ZAP-70 and the study variables. Further studies to evaluate prognostic role of ZAP-70 in Sudanese patients with chronic lymphocytic leukemia are recommended