Effect of Cold Galvanizing Zinc Coating as a Cathodic Protection on Corrosion Rate and Bond Strength of Reinforced Concrete

This study focuses on the corrosion rate of steel in reinforced concrete and its effect on the steel rebar physical properties: Rockwell hardness, Vickers hardness, tensile strength, and yield strength. It was no noticeable effect of the corrosion rate of steel rebar on the physical properties. Tafel test was carried out to analyze the effect of pH and salinity on the corrosion rate of the reinforcement steel. Corrosion rate of reinforced concrete for uncoated and cold galvanized zinc coated steel were investigated at different pH and salinity by using weight loss method. The maximum sheer stress required to pull out the steel samples from the concrete was studied at different pH and salinity solutions by bond strength test. The results showed that at low pH ranges (acidic medium), the corrosion rate of the reinforced concrete was higher than at high pH ranges (alkaline medium), i.e. the corrosion rate is inversely proportional to pH. The corrosion rate of reinforced steel is positively proportional to the salinity until a certain salinity concentration, and then inversely proportional to the salinity due to limited oxygen diffusion. It can be concluded that the corrosion rate of the embedded rebar in reinforced concrete affects its structural performance in two ways, either by reducing its cross-section area or by deteriorating the strength of bonds between the steel and concrete.School of Chemical Engineerin

Effect of Agronomically Selenium Biofortified Hay on Oxidative Status, Metabolic and Inflammatory Biomarkers, and Immune Response of Transition Primiparous Dairy Cows and Se Transfer and Glutathione Peroxidase Activity in their Calves

During the peripartum period (3 weeks before through 3 weeks after calving, a.k.a. “transition”), high producing dairy cows experience, among others, , oxidative stress and immune suppression that compromise performance and increased incidence of diseases.Among trace minerals, supplementation of Selenium (Se) can help to improve the transition by enhancing glutathione peroxidase (GPx) activity and boosting the immune system. Thus, cows during the transition period would benefit from a high amount of Se. Among ways to supplement Se to dairy cows, use of biofortified plants (i.e., the soil is fertilized by inorganic Se that is then incorporated in plant proteins as Se-methionine and Se-cysteine) has proven to be effective in increasing the Se status and improve animals’ health and performance, including their offspring, when fed topregnant beef cows at 2.5 % BW. Different from beef cows, high-producing dairy cows need a more precisely balanced ration that requires a more complex diet; thus, it is not possible to feed only hay. Thus, it remains to be determined if feeding an increased level of Se biofortified hay can be effective in improving the Se status in peripartum high-producing dairy cows. The present dissertation aimed to assess if feeding Se biofortified hay at a level that is more typical for a ration of high-producing dairy cows is an effective way to improve the transition from pregnancy to lactation in high-producing dairy cows. To accomplish the aim, we tested if supplementing high producing dairy cows with 1 kg/100 kg BW (1% BW) of Se biofortified hay was effective in improving 1) Se status (Part 1) and 2) the transition from pregnancy to lactation (Part 2). For the experiment, we used 10 Jersey and 8 Holstein pregnantdairy heifers that were supplemented with 1% BW of Se biofortified (TRT; n=9; 3.2 mg/kg DM Se) or non-biofortified (CTR; n=9; 0.4 mg/kg DM Se) alfalfa hay mixed with the TMR from approx. 40 days prior- to 2 weeks post-partum. The objectives of Part 1 of the experiment were to assess if the aforementioned treatment improved 1) the Se concentration in whole blood, liver, milk, and colostrum; 2) the amount of Se that is transferred into the calves; and 3) the antioxidant activity of cows and calves through the determination of GPx activity. For Part 1, we hypothesized that supplementing primiparous dairy cows with a relatively low amount of Se biofortified hay during the dry period and early lactation enhances the Se concentration and antioxidant status in cows and their calves. Se concentration and other trace minerals in whole blood of cows and claves and liver, milk, and colostrum of cows were measured by using ICP-MS, and GPx activity in samples was measured via a commercial kit. Se concentration in blood was 2-fold higher (P<0.05) in TRT vs. CTR (204.5 vs. 95.0 ng/ml) which resulted in higher Se in liver (1.24 vs 0.62 µg/g dry weight) and colostrum (99.1 vs. 27.2 ng/ml) but not milk. Higher GPx activity in plasma (92.8 vs. 77.9 nmol/min/ml) and erythrocytes (549.2 vs. 260.0 nmol/min/ml) were detected, but not in milk. GPx activity in plasma samples was also higher in TRT vs. CTR (92.8 vs. 77.9 nmol/min/ml) and erythrocytes (549.2 vs. 260.0 nmol/min/ml) but not in milk. Compared to CTR, calves from TRT had higher Se in the blood (215.5 vs. 161.22 ng/ml) but only a numerically (P=0.09) larger GPx activity in plasma. A positive correlation was detected between Se in blood and GPx activity in erythrocytes and plasma in cows. Our results proved that feeding pregnant primiparous dairy heifers with one % BW of Se biofortified alfalfa hay is an efficient way to improve Se status in cows and their calves. Se supplementation increased antioxidant activity via GPx in cows and, numerically, in calves. Feeding Se biofortified hay raised Se level in colostrum but not in milk. Part 2 of the experiment aimed to examine the effect of the treatment on performance, metabolism, oxidative status, and immune response of transition primiparous dairy cows. We hypothesized that supplementing primiparous dairy cows with a relatively small amount of Se biofortified hay during the dry period and early lactation improves performance, metabolism, oxidative status, and immune response. Cows were monitored daily for health status, dry matter intake (DMI), activity, weekly for body weight, and body condition score (BCS). Blood samples were also collected to measure hematocrit (HMC) and metabolic, oxidative, and inflammatory biomarkers. Phagocytosis, white blood cell differential count, and carrageenan skin test (CST) were measured in primiparous cows. Milk yield and components, including fatty acid profile (FA), were determined. Supplementation of primiparous cows with 1% BW of Se-biofortified hay did not affect milk yield or milk components, including fatty acid profile, body weight or DMI. Se biofortified hay affected only a few of the measured parameters in the blood. Albumin level increased, and haptoglobin and urea tended to be increased by supplementation of Se-biofortified hay, indicating a better liver status, especially post-partum. The treatment increased advanced oxidation protein products (AOPP), which is a marker of protein oxidation. An improved antioxidative function of albumin by Se-biofortified hay supplementation was supported by the negative correlation of AOPP with myeloperoxidase and parameters related to inflammation but a positive association with albumin. Se biofortified hay increased hematocrit indicating either a positive effect on erythropoiesis or in lifetime of erythrocytes that could be reduced around calving and/or per effect of severe inflammations. Treatment did not affect any of the measured parameters associated with the immune system. Feeding 1% BW of Se biofortified hay had little effect on metabolic, inflammatory, and oxidative status parameters with no effect on cow’s performance or immune response. Supplementation with Se biofortified hay possibly enhanced liver function, promoted the antioxidant role of albumin, and improved level of red blood cells

An Intelligent Systems Approach to Primary Headache Diagnosis

In this study, the problem of primary headache diagnosis is considered, referring to multiple frames of reference, including the complexity characteristics of living systems, the limitation of human information processing, the enduring nature of headache throughout history, and the potential for intelligent systems paradigms to both broaden and deepen the scope of such diagnostic solutions. In particular, the use of machine learning is recruited for this study, for which a dataset of 836 primary headache cases was considered, originating from two medical centres located in Turkey. Five primary headache classes were derived from the data obtained, namely Tension Type Headache (TTH), Chronic Tension Type Headache (CTTH), Migraine With Aura (MwA), Migraine Without Aura (MwoA), followed by Trigeminal Autonomic Cephalalgia (TAC). A total of 9 machine learning based classi ers, ranging from linear to non-linear ensembles, in addition to 1 random baseline procedure, were evaluated within a supervised learning setting, yielding highest performance outcomes of AUC 0.985, sensitivity 1, and speci city 0.966. The study concludes that modern computing platforms represent a promising setting through which to realise intelligent solutions, which in turn support the space of analytical operations needed to drive forward diagnostic capability in the primary headache domain and beyond

Elektrochemische Untersuchungen an Platin- und Gold-Einkristalloberflaechen

SIGLEAvailable from TIB Hannover: DW 2272 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Comparison of Analytical and Numerical Solutions for ODE-BVP Arising in Heat Transfer Exchanger with a Fin

This research provides the analytical and numerical solution for ODE-BVP (Ordinary differential equation-Boundary value problems) arising in heat transfer exchanger with a fin, and a comparison between these solutions to arrive to a good model of heat transfer process that can use in many kinds of designs of heat exchangers with high efficiency. The comparison of calculations confirmed that the matrix and SOR methods are more accuracy to solve the equation, but they need more work, whereas; the shooting method is easier to solve, faster to converge, but it does not offer a good accuracy because it depends on assuming the initial value of theta. The results showed an agreement between the analytical and the numerical solution, which indicates that the constructed design of the fin, is appropriate to understand the principles of heat transfer by engineers

Distribution of a Fluid over a flat plate slab by diffusion and Convection

This study describes the distribution of a fluid over a flat slab by diffusion and convection. A second order differential equation, which describes this phenomenon, is selected from another paper that is mentioned in the introduction. A theoretical new model is designed in this study to get the mathematical solutions for it. This paper provides the analytical solution by using classic technique method and the numerical solution by using three methods that are matrix method, shooting method, and Successive over Relaxation Method (SOR) method. After the solutions are got, it will be a compression between the analytical and numerical solutions and also between the figure of the previous study and the figures of this study which is got from the results of the analytical and numerical solutions. In addition, there is an experiment is provided in this study to describe how to get the experimental data because the previous study has no experimental data. Finally, it can be concluded from the results that the analytical and numerical solution for equation (7) are match each other and the best step size is ( =0.1). The matrix and SOR methods are more accuracy and appropriate to solve the equation, but they need more work than shooting method

Designing an Integrated Systematic Excavator for Agricultural Land

In this research a complete design of a plough for agricultural land has been achieved. This is a heoretical study, design and invention, for it is considered like the ones available now. Precisely, it is a borne type which can be carried on a vehicle. The optimal design has been reached through making some primary designs for the research on well excavated land by using spiral digging blades which unearths the earth on both sides. These blades are fixed on a subjacent system raised by a hydraulic tool when the digging process finishes. This hydraulic tool enables to obtain a digging successive course by controlling the process of lowering the lower system gradually to perform the digging process by a control system connected to the hydraulic tool. Throughout observation of the previous researches related to plowing [2, 3], it has been found that loads are put on the most digging blades of the ploughs to increase the digging efficiency and to reach deeper points. This has been taken into account in our presented research by designing springs between the lower system mentioned above and the upper fixed system. From this we get a downward force which will be observed by detailed drawings. Besides, hindering digging blades by solid materials in the earth has been given attention for they penetrate the earth to a depth of (30 cm) by our designing the springs to raise the lower system when hindered and later to reach a system design as a whol