Effects of Speed on Draft for Selected Tractor-Driven Tillage Implements in Samaru Soil, Zaria, Nigeria

The objective of this study was to determine the effects of speed on drafts of some selected tractordriven tillage implements in Samaru soil in order to address the problem of inadequacy of local design data, inappropriateness and inadaptability of such imported implements. Three tillage implements were used at three tractor  speeds on the field at three tillage depths using two Eicher tractors (5660). The draft forces replicated, three times, were measured using dynamometer. Soil samples collected from different points in the field were analyzed for moisture content (MC), humus content and bulk density (BD). The results showed that draft of the three implements were related to the speed of the tractor. Result obtained also showed MC varies from 8.40-15.11%, BD varies from 1.62-1.77g/cm3 and humus  content from 4.207-0.625% down the soil profile. At the lowest MC of 8.40%, drafts of 3.07, 5.13 and 9.33kN at speed  2.5 m/s were obtained for the selected implements. Drafts of 2.00, 2.80 and 4.03kN were obtained at the highest MC of  15.11% at 2.5m/s speed. It is clear from the experiment that draft increases with increase in speed for disc plough, disc  harrow, tillage depths and BD, while draft decreases with increase in MC and speed of mouldboard ridger. The best speed  for tillage is 2.5 m/s obtained at optimum MC 10.67–15.11% for soil under consideration. Disc plough requires highest  draft 2.8-9.33kN followed by mouldboard ridger 4.03-5.83kN and disc harrow requires least draft 2.0-3.57kN at each of  the three speeds considered

Assessment of concentration level of some heavy metals and non -metallic ions in dumpsite soils in the Federal Capital Territory, Nigeria

The concentration of heavy metals (Fe, Cd, Cr, Cu, Pb, Mn, Ni and Zn), pH and non-metallic ions (Cl-, NO3- and SO42-) in soil samples from dumpsites and soil samples from areas without dumpsites (control) in the study area were determined at depth 0-15cm, 45-60cm and 85-100cm.The digestion of samples was done using concentrated nitric acid. The Atomic Absorption Spectrophotometer (AAS) and titration methods were used to determine heavy metals and non-metallic ions respectively. At depth 0-15cm, heavy metal concentration in the dumpsite soil in both seasons were; Fe (19.8911 and 21.8488 mg/g), Cd (0.0012 and 0.0017 mg/g), Cr (0.7610 and 0.2285 mg/g), Cu (0.3657 and 0.1259 mg/g), Pb (0.5063 and 0.9991 mg/g), Mn (6.3547 and 3.446 mg/g), Ni (0.2549 and 0.1247 mg/g), Zn (1.2057 and 3.2462 mg/g). In both seasons control Fe (18.0275 and 14.5668 mg/g), Cd (0.0078 and 0.0000 mg/g), Cr (0.1768 and 0.2643 mg/g), Cu (0.0308 and 0.0528 mg/g), Pb (0.0201 and 0.3776 mg/g), Mn (0.0824 and 0.1163 mg/g), Ni (0.0256 and 0.0000 mg/g), Zn (0.0695 and 0.8055 mg/g). Heavy metal contents for soil samples across the profile depth at 0-15cm, 45-60cm and 85-100cm were also significantly higher at P<0.05 from top down wards as well as between soil and control. Assessed parameters for dumpsite soil samples at depth 0-15cm, 45-60cm and 85-100cm all exceeded the WHO international standards in both seasons. It is therefore concluded that the waste dumpsites have negative impact on the quality of soil the study area. As such, there is need for government to overhaul her approach towards management of waste dumpsites and also to develop better waste management practices with regard to municipal solid waste management to mitigate soil pollution and its attendant implications in the FCT.Keywords: Soil Pollution, Waste dumpsite, Municipal Solid Waste Management, Sustainable Developmen

Prediction Modeling of 28-Day Concrete Compressive Strength using Artificial Neutral Network

Compressive strength of concrete at the age of 28 days is an important parameter for the design of concrete structures and waiting for that length of time to obtain the value can be tasky. This study developed an alternative approach using Artificial Neutral Network (ANN) to estimate or predict the compressive strength of concrete at 28th day from early age results. In the study concrete cubes of mix ratio 1:2:4 were cast with different water-cement ratios (0.4, 0.5, 0.6 and 0.65) and their seventh (7th) and twenty-eighth (28th) day strength were measured in the laboratory. In all, 400 cubes of 150 x 150 x 150mm of 200 sets were subjected to compressive strength test using Avery Denison Universal Testing Machine of 2000 kN load capacity at a constant load application of 15kN/s. ANN model was then developed using the time series tool of ANN in MATLAB 7.12.0 (R2011a) applying back propagation algorithm. Out of the 200 sets of results, 110 sets (55%) were used for the training of the network while 30 sets (15%) were used to validate and 60 sets (30%) to test the network. The result of the crushing test shows that the higher the compressive strength at seventh (7th) day the higher it will be at twenty-eighth (28th) day. The result of the ANN model shows a good correlation between the seventh (7th) day compressive strength and the twenty-eighth (28th) day compressive strength with training and validation correlation coefficients of 0.99751 and 0.99736 respectively. It was also found that the ANN model is quite efficient in determining the twenty-eighth (28th) day compressive strength of concreteas the predicted strength values match very well with those obtained experimentally with a correlation coefficient of 0.99675

Effects of rice husk ash on durability of self-compacting concrete made with cassava peel ash

Self-compacting concrete (SCC) is a highly flowable concrete with improved strength and surface smoothness. The preparation of SCC requires high amount of cement. This utilizes tremendous amount of energy and releases carbon dioxide into the atmosphere. It is critical to reduce CO2 emissions during Portland cement (PC) manufacture by partially replacing cement in the SCC. This study evaluates the durability characteristics of SCC produced using cassava peel ash (CPA) combined with rice husk ash (RHA) at 5, 10, 15, 20, and 25 percent cement replacement levels respectively. The effects of water absorption, H2SO4 attack, MgSO4 attack, and high heat on SCC made with CPA and RHA blends were examined. The results show that, as CPA and RHA proportions rise by approximately 5% CPA and 10% CPA+RHA substitution, SCC compressive strength equates to design strength (grade 35). It was also discovered that CPA and RHA both enhance resistance to H2SO4 and MgSO4 degradation, but perform poorly when exposed to elevated temperatures when compared to the control specimen. However, when CPA is utilized with RHA in SCC, the rate of water absorption is reduced to a minimum due to an enhanced pore structure of the CPA-SCC specimen. Generally, a 5% CPA content is considered as the optimum replacement of cement for self-compacting concrete with grade 35

A circular RNA generated from an intron of the insulin gene controls insulin secretion.

Fine-tuning of insulin release from pancreatic β-cells is essential to maintain blood glucose homeostasis. Here, we report that insulin secretion is regulated by a circular RNA containing the lariat sequence of the second intron of the insulin gene. Silencing of this intronic circular RNA in pancreatic islets leads to a decrease in the expression of key components of the secretory machinery of β-cells, resulting in impaired glucose- or KCl-induced insulin release and calcium signaling. The effect of the circular RNA is exerted at the transcriptional level and involves an interaction with the RNA-binding protein TAR DNA-binding protein 43 kDa (TDP-43). The level of this circularized intron is reduced in the islets of rodent diabetes models and of type 2 diabetic patients, possibly explaining their impaired secretory capacity. The study of this and other circular RNAs helps understanding β-cell dysfunction under diabetes conditions, and the etiology of this common metabolic disorder

Are there differences in acute phase inflammation markers regarding the type of heart failure?

This study aimed to determine if there are differences in inflammatory markers in the acute phase between systolic heart failure and heart failure with preserved systolic function. One hundred and thirty-one patients with acute heart failure were recruited consecutively. At admission, plasma fibrinogen, C-reactive protein, sialic acid, von Willebrand factor, vascular endothelial growth factor, interleukin-6 and NTproBNP were all evaluated. If the ejection fraction was 45% or over patients were included in the HF-PSF group; the remaining patients were included in the SHF group. The HF-PSF patients were older (72±10 vs 63±12 years, P<0.001), presented a higher rate of atrial fibrillation (56.1 vs 21.3%, P<0.001), and had a lower rate of hemoglobin (12.2±2 vs 13.3±2.1 g/dL, P<0.01). No significant differences were observed in the inflammation markers analyzed among SHF and HF-PSF groups. In the acute phase of heart failure there is a marked elevation of inflammatory markers but there are no differences in the inflammatory markers analyzed between the two different types of heart failure

Coherent π0 photoproduction on the deuteron up to 4 GeV

The differential cross section for 2H(γ,d)π0 has been measured at deuteron center-of-mass angles of 90° and 136°. This work reports the first data for this reaction above a photon energy of 1 GeV, and permits a test of the apparent constituent counting rule and reduced nuclear amplitude behavior as observed in elastic ed scattering. Measurements were performed up to a photon energy of 4.0 GeV, and are in good agreement with previous lower energy measurements. Overall, the data are inconsistent with both constituent-counting rule and reduced nuclear amplitude predictions

Measurements of Deuteron Photodisintegration up to 4.0 GeV

The first measurements of the differential cross section for the d(γ,p)n reaction up to 4.0 GeV were performed at the Continuous Electron Beam Accelerator Facility (CEBAF) at Thomas Jefferson Laboratory. We report the cross sections at the proton center-of-mass angles of 36°, 52°, 69°, and 89°. These results are in reasonable agreement with previous measurements at lower energy. The 89° and 69° data show constituent-counting-rule behavior up to 4.0 GeV photon energy. The 52° and 36° data disagree with the counting-rule behavior. The quantum chromodynamics (QCD) model of nuclear reactions involving reduced amplitudes disagrees with the present data.U.S. Department of Energy, National Science Foundatio

Uplift behavior of anchor plates in slope

The Geo-Institute of the American Society of Civil Engineers2013 Congress on Stability and Performance of Slopes and Embankments III, Geo-Congress 2013 --3 March 2013 through 7 March 2013 -- San Diego, CA --This paper presents the results of numerical analyses investigating the uplift capacity of anchor plates located near sandy earth slopes. Many factors, such as relative density of sand, embedment ratio of anchor plate, inclination angle of slope, and the location of the anchor plate relative to the slope crest, have been investigated using finite element analysis (FEA). The results were presented in terms of a non-dimensional uplift capacity ratio (UCR). It was clearly noted that the distance of anchor plate to the slope crest affects the uplift capacity where the uplift capacity increases as the anchor move away from the slope crest. Based on the FEA, it can be concluded that the relative density of sand and the embedment ratio of anchor plates are the main factors affecting the uplift capacity. © 2013 American Society of Civil Engineers

Investigation of effects of temperature cycles on soil-concrete interface behavior using direct shear tests

This publication was made possible by NPRP Grant NPRP-9-080-2-039 from Qatar National Research Fund (a member of the Qatar Foundation). L. M. Calado acknowledges Fundação para a Ciência e Tecnologia ( FCT ) for Ph.D. grant SFRH/BD/127341/2016 . Authors from Portugal acknowledge FCT for the additional funding under the projects UID/QUI/00100/2013 and UID/QUI/00100/2019 ; Sherwin-Williams for providing the coating formulations; Voestalpine AG for providing carbon steel; Dr. Marta Alves (Instituto Superior Técnico) for conducting the XRD tests; Dr. Sónia Eugénio (Universidade Atlântica) and Mário Vale (Instituto Superior Técnico) for performing FTIR and TG/DTG studies; Dr. Nick Laycock and Dr. Abitha Ramesh (Qatar Shell Research and Technology Centre) for the helpful technical guidance. Statements made herein are solely the responsibility of the authors.This work was made possible by an NPRP 7-725-2-270 a grant from the Qatar National Research Fund (a member of the Qatar Foundation ). The statements made herein are solely the responsibility of the authors.Scopu