New Concrete Technology Negates Traditional Concrete Placement in Sudan

Self-consolidating concrete, also known as self-compacting concrete (SCC), is an innovative concrete that does not require vibration for placing and compaction. The mixture qualification process of Self Compacting Concrete consists from a small, well controlled laboratory batches are tested, second, the closest mixture/s is tested in production, which includes the use of batch mixing, and placing equipment, and finally a quality assurance/control plan for the fresh and hardened properties is developed. However, this paper presents a full research addressed only a small, well controlled laboratory batches and the laboratory testing phase of the mixture qualification process. For the purpose of study, a small, well controlled laboratory batches are tested using available locally aggregates in Sudan. Therefore, Slumpflow, V-funnel, L-box shape, J-ring, and Sieve stability tests of concrete mixtures were used to determine the flowability, passing ability and segregation resistance of SCC mixtures. The produced self compacting concrete is successfully confirmed the fresh properties of SCC with Slumpflow in range of 650 to 850 mm with high viscosity and excellent segregation resistance. The hardened properties of concrete were also considered and tested. The strength of SCC was found to be same or higher than that of normally vibrated concrete with the same constituent materials. SCC has relatively higher dynamic modulus of elasticity ranged between 38 to 42 GPa, in comparison to normally vibrated concrete for the same strength range of 50 to 60 MPa. Whereas the Spilt Tensile and Flexural strength of SCC are of 2.5 MPa and 10 MPa respectively. The major difficulty which was faced in development of SCC was on account of contradictory factors that the concrete should be fully flowable but without bleeding or segregation. It is required that the cement mortar of the SCC should have higher viscosity to ensure flowability while maintaining non-sedimentation of aggregates and that was achieved by using high content of powder (fine materials less than 0.15 mm includes cementitious materials). Achievement of durable concrete structures independent of the quality of construction work by using Self Compacting Concrete (SCC) has been proposed to solve the problem of the durability of concrete structures due to the gradual reduction of adequate compaction and skilled workers and for complex shape for the prestressed and precast industries in Sudan. The features of high benefit of fluidity and self consolidation will result in a variety of potential benefits for the end-user. Other benefits of the application of this new concrete technology require effort to be achieved. Moreover, areas such as quality control, mixture development, and logistics may need modification or expand resources when develop self-compacting concrete in Sudan. Keywords: Self Compacting Concrete (SCC), Sudan, Flowability, Passing ability, Segregation Resistance Slumpflow, V-funnel, L-box shape, J-ring, and Sieve stability, Powder conten

Understanding the routes of contamination of ready-to-eat vegetables in the Middle East

publisher: Elsevier articletitle: Understanding the routes of contamination of ready-to-eat vegetables in the Middle East journaltitle: Food Control articlelink: http://dx.doi.org/10.1016/j.foodcont.2015.10.024 content_type: article copyright: Copyright © 2015 Elsevier Ltd. All rights reserved

Two records of Macrophthalmus Desmarest, 1823 (Decapoda: Brachyura: Thoracotremata) from the NW of the Arabian Gulf

Specimens of two crabs Macrophthalmus dentipes Lucas, 1836 and Macrophthalmus laevis A. Milne-Edwards, 1867 were collected from the intertidal zone of the lower reaches of Shatt Al-Arab at Fao region, Basrah, Iraq, 2012. A note on the morphological features of these two species and a photograph is provided to confirm the identification of the crabs

INFLUENCE OF A LOW TEMPERATURE AGEING ON THE PROPERTIES OF AL-6.5%SI-0.35%MG ALLOY

The effect of a low temperature ageing treatment on the hardness, tensile and corrosion characteristics of sand cast Al-6.5%Si-0.35%Mg alloy was studied. The temper conditions are low temperature ageing at 90oC, 95oC, 100oCand 105oC respectively followed by ageing to 180oC for 2 hrs. This was compared with the control sample which was aged directly to 180oC for 2hrs. The hardness of the Al-6.5%Si-0.35%Mg alloy was measured using the Rockwell-HRB scale hardness tester, while the tensile characteristic was evaluated using a graphical tensometer. The corrosion resistance of the alloy was evaluated using weight loss analysis in simulated sea water environment. An increase in the hardness characteristic was observed in the low temperature ageing at 90oC (7.8 HRB) as compared with (6.0 HRB) that was obtained for the control. From the tensile results obtained, the extension value for the control samples was (1.4 mm) while the sample with a low temperature ageing of 105oC gave the highest extension of (2.26 mm). Remarkable decrease in corrosion rate was observed at 95oC (2.3373 mm/yr x10-7) as compared with the control of (5.2049 mm/yr x10-7). From the Optical Microscope (OPM) and Scanning electron microscope (SEM) results, it was observed that the microstructures were refined for low temperature ageing when compared with the control samples. From these results, it can be deduced that the low temperature ageing treatment had an appreciable influence on the properties of this alloy. http://dx.doi.org/10.4314/njt.v35i3.1

Excessive adventitial stress drives inflammation-mediated fibrosis in hypertensive aortic remodelling in mice

Hypertension induces significant aortic remodeling, often adaptive but sometimes not. To identify immuno-mechanical mechanisms responsible for differential remodeling, we studied thoracic aortas from 129S6/SvEvTac and C57BL/6J mice before and after continuous 14-day angiotensin II infusion, which elevated blood pressure similarly in both strains. Histological and biomechanical assessments of excised vessels were similar at baseline, suggesting a common homeostatic set-point for mean wall stress. Histology further revealed near mechano-adaptive remodeling of the hypertensive 129S6/SvEvTac aortas, but grossly maladaptive remodeling of C57BL/6J aortas. Bulk RNA sequencing suggested that increased smooth muscle contractile processes promoted mechano-adaptation of 129S6/SvEvTac aortas while immune processes prevented adaptation of C57BL/6J aortas. Functional studies confirmed an increased vasoconstrictive capacity of the former while immunohistochemistry demonstrated marked increases in inflammatory cells in the latter. We then used multiple computational biomechanical models to test the hypothesis that excessive adventitial wall stress correlates with inflammatory cell infiltration. These models consistently predicted that increased vasoconstriction against an increased pressure coupled with modest deposition of new matrix thickens the wall appropriately, restoring wall stress toward homeostatic consistent with adaptive remodeling. In contrast, insufficient vasoconstriction permits high wall stresses and exuberant inflammation-driven matrix deposition, especially in the adventitia, reflecting compromised homeostasis and gross maladaptation

Is the Public willing to help the Nigerian Police during the Boko Haram crisis? A look at moderating factors.

This paper sought the opinion of 200 Nigerians on their willingness to cooperate with the Police during the Boko Haram crisis. Public perceptions of Police effectiveness during the crisis, residence location, gender and religious affiliation were used as moderators. Data was analysed using an explanatory factor analysis and structural equation modelling. Results indicated a strong association between perceived effectiveness and willingness to report to the Police with respondents who question the effectiveness of the Police being less likely to be willing to report criminal activity about Boko Haram. Further to this, the impact of religion on willingness to report was at least partially mediated by perceived effectiveness of the Police with the results showing that Christian respondents perceived the Police as less effective. Females and those living in the North were significantly less willing to report criminal activity to the Police The findings are then discussed in relation to the BH crises and directions for future research are given

Outcomes 1 year after non-operative management of uncomplicated appendicitis in children: Children with AppendicitiS during the CoronAvirus panDEmic (CASCADE) study

BACKGROUND: A major shift in treatment of appendicitis occurred early in the SARS-CoV-2 pandemic with non-operative management used commonly outside research protocols and in units with limited previous experience. This study aims to compare real-world outcomes of surgery versus non-operative management of uncomplicated appendicitis in children with 1-year follow-up. METHOD: A prospective multicentre observational study of children treated for uncomplicated appendicitis at 74 hospitals in the UK and Ireland from 1 April to 31 July 2020 was performed. Propensity-score matched analysis was conducted using age, sex, C-reactive protein at diagnosis and duration of symptoms as covariates. Primary outcomes were success of non-operative management defined as achieving 1-year follow-up without undergoing appendicectomy due to recurrent appendicitis or ongoing symptoms, and occurrence of any predefined complication (intra-abdominal collection, wound infection, bowel obstruction or reintervention). RESULTS: Of 1464 children with presumed uncomplicated appendicitis, 1027 (70.2 per cent) underwent surgery and 437 (29.9 per cent) underwent non-operative management. Ninety-four children (21.5 per cent) treated by initial non-operative management required appendicectomy during the index hospital admission while recurrent appendicitis after discharge occurred in 25 (10.4 per cent) children within 1 year. The overall success rate of non-operative management at 1 year was 63.1 per cent (95 per cent c.i. 58.0 to 68.3 per cent). For propensity-score matched analyses, 688 children undergoing surgery and 307 undergoing non-operative management were included. Any predefined complication occurred in 50 (7.3 per cent) children undergoing surgery and in four (1.3 per cent) children undergoing non-operative management (OR 5.9 (95 per cent c.i. 2.1 to 16.6)) in the propensity-score matched cohort. There was no mortality or stoma formation. CONCLUSION: Non-operative management is a safe and valid alternative to appendicectomy in children with uncomplicated appendicitis

Bioavailability and Antihyperglycemic Effect of Four Glibenclamide Tablets: a Comparative Study

In this study, we compared the bioavailability and antihyperglycemic effect of glibenclamide tablets 5 mg available in Sudan. Nine healthy subjects were given a 5 mg dose of either micronized glibenclamide tablets (Euglucon®) or conventional non-micronized glibenclamide tablets (locally manufactured items). Blood samples were collected at 0, 1, 2, 3, 4, 5, 6, 7 and 8h and analyzed for glucose concentrations. The maximum mean serum concentration of the drug (Cmax) and the mean time to maximum serum concentration (Tmax) were calculated and the area under the concentration versus time curve (AUC) and the drug clearance (Cl) were also recorded. The mean glucose concentration was also determined in different time intervals. The obtained results show no significant difference in the mean Tmax between the tested items. However, the mean Cmax is significantly higher (p 0.001) when the non-micronized tablets are taken (456 ng/mL) rather than the micronized tablets (291 ng/mL). Similarly, the mean AUC0-8h is significantly higher (p 0.001) with the non-micronized tablets (1915 ng/mL.h) than with the micronized tablets (1163 ng/mL.h). After 8 h, the subjects in the micronized group had a drug clearance of 0.0430 L/Kg.h and a clearance of 0.0260 L/Kg.h is recorded in the unmicronized group. Both tablets lower the mean glucose concentrations of the 9 volunteers after 8 h, 99 mg/dL for micronized tablets and 98 mg/dL for non-micronized tablets. Overall, the non-micronized glibenclamide tablet used in this study was similarly lowers the glucose concentrations in healthy volunteer subjects to that of imported micronized glibenclamide tablets