Effects of limestone and super-plasticizer on the fresh properties of self-compacting concrete

The free flow ability of fresh self-compacting concrete (SCC), capable of overcoming obstacles and penetrating into difficult joints is one of the special properties that differentiate SCC from normal concrete. It can then be rightly said that the fresh property of self compacting concrete (SCC) is the most important factor that distinguishes SCC from conventional concrete. Due to the importance of this property to the overall performance of self-compacting concrete, the tests of fresh SCC must be gotten right since any mistake will compromise the essence of recurring to SCC in place of normal concrete. This research attempts to enhance the flow-ability of SCC via replacement of cement with varying dosage of limestone and super-plasticizer. To validate the improvement of SCC fresh properties, slump test is used to assess workability, L-box test for passing ability and V-funnel test for filling ability. Test results analyzed with statistical tools confirmed that the workability and rheological properties of self-compacting concrete can be improved through the adoption of various dosages of limestone powder. Keywords: Self-Compacting Concrete, Limestone powder, Fresh properties

NFRP strengthening of reinforced concrete beams

Publisher PD

Assessment of Compressive Strength of Concrete Produced from Different Brands of Portland Cement

Concrete is basically a mixture of two components: aggregates and paste. The paste, comprised of Portland cement and water, binds the aggregates (usually sand and gravel or crushed stone) into a rocklike mass as the paste hardens because of the chemical reaction of the cement and water. In our society today some of the cement brands that are being sold are not up to standard and this may be traced to negligence on the part of the manufacturers by paying very little attention to the quality and also the regulatory body does not put strict measures to enforce the required standard. This problem has led to the production of poor quality concrete that increases the risk of collapse of building structures. This research determined the cement brands that have the highest compressive strength to enhance the quality and durability of the structures being built in the country. Different brands of Portland cement were used to produce concrete varying with1:2:4 and 1:3:6 mix ratio respectively with a curing date of 3, 7, 14, 21, and 28 days respectively. No additive was used in any of the mix. The tests carried out include slump test at its fresh state while compressive strength was carried out for the hardened concrete, also the vicat test was carried out on the cement brands to determine the setting time. Compressive strength at 28 days showed that Dangote 3X cement produced 25.27N/mm2, Ibeto cement 38.89 N/mm2, Purechem cement 24.58 N/mm2, Unichem cement 21.16 N/mm2 and Elephant cement 27.9 N/mm2 for 1:2:4 mix ratio respectively. For 1:3:6 mix ratio at 28 days Dangote cement produced 18.89 N/mm2, Ibeto cement 22.07 N/mm2, Purechem cement 11.63 N/mm2,Unichem cement 15.86 N/mm2 and Elephant cement 16.71 N/mm2 respectively. The study concluded that Ibeto cement has the highest strength at 28 days for 1:2:4 and 1:3:6 mix ratios respectively. Keywords: Cement, Compressive strength, Concrete, Fresh Property, Portland Cemen

Assessment of Compressive Strength of Concrete Produced from Different Brands of Portland Cement

Concrete is basically a mixture of two components: aggregates and paste. The paste, comprised of Portland cement and water, binds the aggregates (usually sand and gravel or crushed stone) into a rocklike mass as the paste hardens because of the chemical reaction of the cement and water. In our society today some of the cement brands that are being sold are not up to standard and this may be traced to negligence on the part of the manufacturers by paying very little attention to the quality and also the regulatory body does not put strict measures to enforce the required standard. This problem has led to the production of poor quality concrete that increases the risk of collapse of building structures. This research determined the cement brands that have the highest compressive strength to enhance the quality and durability of the structures being built in the country. Different brands of Portland cement were used to produce concrete varying with1:2:4 and 1:3:6 mix ratio respectively with a curing date of 3, 7, 14, 21, and 28 days respectively. No additive was used in any of the mix. The tests carried out include slump test at its fresh state while compressive strength was carried out for the hardened concrete, also the vicat test was carried out on the cement brands to determine the setting time. Compressive strength at 28 days showed that Dangote 3X cement produced 25.27N/mm2, Ibeto cement 38.89 N/mm2, Purechem cement 24.58 N/mm2, Unichem cement 21.16 N/mm2 and Elephant cement 27.9 N/mm2 for 1:2:4 mix ratio respectively. For 1:3:6 mix ratio at 28 days Dangote cement produced 18.89 N/mm2, Ibeto cement 22.07 N/mm2, Purechem cement 11.63 N/mm2,Unichem cement 15.86 N/mm2 and Elephant cement 16.71 N/mm2 respectively. The study concluded that Ibeto cement has the highest strength at 28 days for 1:2:4 and 1:3:6 mix ratios respectively. Keywords: Cement, Compressive strength, Concrete, Fresh Property, Portland Cemen

The use of peripheral blood cells as an assessment of inflammation in prostate cancer in patients attending in surgery department at ESUT teaching hospital, Parklane, Enugu, Nigeria

Background: Full blood count (FBC) is a prerequisite investigation requested from all prostate cancer (PCa) patients pre and post treatment, poor parameter influences the outcome of cancers.Methods: Total subjects consisted of 84 male subjects between the ages 41 to >80 years. Longitudinal study was conducted. Controls and test samples were collected at diagnosis and at different stages of the treatment. Demographic information was obtained using a questionnaire. The data was analyzed using IBM statistical package for social sciences (SPSS) PC, version 20.0; SPSS Inc., Chicago, III., USA; the receiver operating characteristic curve (ROC) curve was obtained via neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR) and platelet-to-lymphocyte ratio (PLR) ratios cut-off determinations. Cox proportional-hazards regression analyses the prognostic factors (duration, ratios) and overall survival (diagnosis to death or last follow-up). A paired sample t-test compared test of significance in pre/post treatment results. The analysis of variance (ANOVA) and Tukey HSD post-hoc, test susceptibility within age groups was done.Results: Increased NLR and LMR were significantly associated with increased hazard ratio (HR) and OS at p0.05 in PCa. In complete blood count (CBC) and erythrocytic sedimentation rate (ESR), control and treatment period, all red blood cell (RBC) parameters showed a significant decrease at p<0.05 in treatment results compared to the pre-treatment results while total platelet (TPLT), total white blood cells (TWBC), NC, LC, ESR showed significant increase at p<0.05 in treatment results compared to pre-treatment results. Age group 41-50 years showed more susceptibility than other age groups with significant decrease at p<0.05 in NC, LC and increased MC.Conclusions: This study supports CBC and ESR biomarkers as a prognostic tool in early detection, treatment and monitoring of disease progression in these subjects

Detection of IL28B SNP DNA from Buccal Epithelial Cells, Small Amounts of Serum, and Dried Blood Spots

Background &amp; Aims: Point mutations in the coding region of the interleukin 28 gene (rs12979860) have recently been identified for predicting the outcome of treatment of hepatitis C virus infection. This polymorphism detection was based on whole blood DNA extraction. Alternatively, DNA for genetic diagnosis has been derived from buccal epithelial cells (BEC), dried blood spots (DBS), and genomic DNA from serum. The aim of the study was to investigate the reliability and accuracy of alternative routes of testing for single nucleotide polymorphism allele rs12979860CC. Methods: Blood, plasma, and sera samples from 200 patients were extracted (400 mL). Buccal smears were tested using an FTA card. To simulate postal delay, we tested the influence of storage at ambient temperature on the different sources of DNA at five time points (baseline, 48 h, 6 days, 9 days, and 12 days) Results: There was 100 % concordance between blood, plasma, sera, and BEC, validating the use of DNA extracted from BEC collected on cytology brushes for genetic testing. Genetic variations in HPTR1 gene were detected using smear technique in blood smear (3620 copies) as well as in buccal smears (5870 copies). These results are similar to those for whole blood diluted at 1/10. A minimum of 0.04 mL, 4 mL, and 40 mL was necessary to obtain exploitable results respectively for whole blood, sera, and plasma. No significant variation between each time point was observed for the different sources of DNA. IL28B SNPs analysis at these different time points showed the same results using the four sources of DNA

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p&lt;0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p&lt;0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

Studies of crystalline CdZnTe radiation detectors and polycrystalline thin film CdTe for X-ray imaging applications.

The development of a replacement to the conventional film based X-ray imaging technique is required for many reasons. One possible route for this is the use of a large area film of a suitable semiconductor overlaid on an amorphous silicon readout array. A suitable semiconductor exists in cadmium telluride and its tertiary alloy cadmium zinc telluride. In this thesis the spectroscopic characteristics of commercially available CZT X- and gamma-radiation detectors are established. The electronic, optical, electro-optic, structural and compositional properties of these detectors are then investigated. The attained data is used to infer a greater understanding for the carrier transport in a CZT radiation detector following the interaction of a high energy photon. Following this a method used to fabricate large area films of CdTe on a commercial scale is described. This is cathodic electrodeposition from an aqueous electrolyte. The theory and experimental arrangement for this technique are described in detail with preliminary results from the fabricated films presented. Attention is then turned to the CdS/CdTe films that are produced commercially for the photovoltaic industry. In this case the crystalline nature, surface topography and optical properties are investigated. A conclusion examines the progress that has been made towards the development of a large area flat panel digital imaging technique