766 research outputs found
Point-of-Care for Evaluating Antimicrobial Resistance through the Adoption of Functional Materials
SEROMONITORING OF AVIAN INFLUENZA H9 SUBTYPE IN BREEDERS AND COMMERCIAL LAYER FLOCKS
A serological survey for detection of antibodies against avian influenza virus (AIV) subtype H9 in vaccinated layer flocks was carried out. Serum samples were divided into age groups A, B, C, D (commercial layers) and E, F, G, H (layer breeders). Haemagglutination inhibition (HI) test was performed to determine serum antibodies against AIV-H9 subtype. Geometric mean titer (GMT) values were calculated. Results showed the level of protection of vaccinated birds was satisfactory
Direct bandgap materials based on the thin films of SexTe100 - x nanoparticles
In this study, we fabricated thin films of Se(x)Te(100 − x) (x = 0, 3, 6, 9, 12, and 24) nanoparticles using thermal evaporation technique. The results obtained by X-ray diffraction show that the as-synthesized nanoparticles have polycrystalline structure, but their crystallinity decreases by increasing the concentration of Se. They were found to have direct bandgap (E(g)), whose value increases by increasing the Se content. These results are completely different than those obtained in the films of Se(x)Te(100 − x) microstructure counterparts. Photoluminescence and Raman spectra for these films were also demonstrated. The remarkable results obtained in these nanoparticles specially their controlled direct bandgap might be useful for the development of optical disks and other semiconductor devices
Effect of Styrene Butadiene Rubber Latex on Mechanical Properties of Eco Concrete: Limestone Powder Concrete
To make concrete a truly green material, viable cement substitutes are available. This experimental investigation is performed to study the effect of using limestone powder (LSP) and styrene butadiene rubber (SBR) latex in the concrete mix. In this work, a concrete with 1:1.8:3 cementitious material:sand:gravel and water/cement ratio w/c of 0.5 is produced. First, LSP is used with 0, 5, 10, 15, and 20% replacements by weight of cements. The fineness of the LSP is measured using sieve No. 200 and showed about 30% pass. Second, and to improve the matrix of concrete due to the dilution effect, four ratios of SBR latex (0, 5, 10, and 15%) are added by weight of cements to the mix for each LSP ratio. Compressive strength at ages of 3, 7, 14, 28, and 90 days is tested for the concrete specimens mixed with LSP only to examine its effect on concrete strength’s development with time, whereas strengths are recorded at the age of 28 days for the other concretes. Three prisms were cast for each ratio and tested at 28 days. The results show general improvements in terms of compressive and flexural strengths
Evaluation of the effect of type II diabetes mellitus on Bone Mineral Density of Upper and Lower Limbs by Dual-Energy X-Ray Absorptiometry
Background: Bone mineral density has been assessed using Dual-Energy X-Ray Absorptiometry. Bone mineral density is measured according to the results of the Dual-Energy X-Ray Absorptiometry examination of the vertebral column and pelvis. Although diabetes mellitus type II (DM) is known to affect bone mineral density, at the present time this particular relationship is not clear.
Objective: The aim of current study was to evaluate the effects of type II diabetes mellitus on bone mineral density of the upper and lower limbs as well as gender differences.
Patients and Methods: This study involved 165 patients complaining of bone pain (85 males and 80 females), 85 patients of who suffered from diabetes, involving both genders. In addition, 90 apparently healthy volunteers had been studied and were considered to constitute the control group. All individuals (255) were studied regarding their bone mineral density via Dual-Energy X-Ray Absorptiometry for all parts of the body.
Results: The Dual-Energy X-Ray Absorptiometry exam revealed highly statistically significant differences between the sides of the body in the same person. In addition, there were significant differences in bone mineral density between females and males, as well as between the control and patient groups with type II diabetes mellitus.
Conclusion: Our results indicated that the bone mineral density of women was less than that in men in all cases (normal, osteoporosis, and diabetes mellitus type II (DM) with osteoporosis). Other results obtained from this research revealed that diabetes mellitus type II (DM) can be considered to be one of the major causes of osteoporosis in the general populatio
The effect of coarse aggregate inclusion on the performance of reactive powder concrete exposed to oil products.
Reactive powder concrete, RPC, is an ultra-high strength and high ductility cementitious composite with advanced mechanical and physical properties. RPC is composed of very fine powders (cement, sand, quartz powder and silica fume), steel fibers (optional) and superplasticizer.
A basic principle, which was presented by the first developers of RPC, is to eliminate the coarse aggregate in mixture to enhance homogeneity. The main purpose of the present investigation is to modify RPC by including natural graded coarse aggregate in the mixture in different approaches.
The investigation was devoted to monitor the strength development, total absorption and permeability of RPC after exposure to two types of oil products, kerosene and gas oil, up to 180 days. The current results showed that eliminating coarse aggregate as a principle could be gone beyond. The better way for including coarse aggregate in RPC was to replace the fine sand and the most useful FA/A ratio is expected to be within the range of 0 - 25 % by weight. This range was found to create an optimum situation between strength and absorption for kerosene and gas oil exposures. It is not recommended to include the coarse aggregate in RPC mixtures as a replacement to the binder specially when dealing with oil products storage
Evaluation of the effect of type II diabetes mellitus on Bone Mineral Density of Upper and Lower Limbs by Dual-Energy X-Ray Absorptiometry
Background: Bone mineral density has been assessed using Dual-Energy X-Ray Absorptiometry. Bone mineral density is measured according to the results of the Dual-Energy X-Ray Absorptiometry examination of the vertebral column and pelvis. Although diabetes mellitus type II (DM) is known to affect bone mineral density, at the present time this particular relationship is not clear.
Objective: The aim of current study was to evaluate the effects of type II diabetes mellitus on bone mineral density of the upper and lower limbs as well as gender differences.
Patients and Methods: This study involved 165 patients complaining of bone pain (85 males and 80 females), 85 patients of who suffered from diabetes, involving both genders. In addition, 90 apparently healthy volunteers had been studied and were considered to constitute the control group. All individuals (255) were studied regarding their bone mineral density via Dual-Energy X-Ray Absorptiometry for all parts of the body.
Results: The Dual-Energy X-Ray Absorptiometry exam revealed highly statistically significant differences between the sides of the body in the same person. In addition, there were significant differences in bone mineral density between females and males, as well as between the control and patient groups with type II diabetes mellitus.
Conclusion: Our results indicated that the bone mineral density of women was less than that in men in all cases (normal, osteoporosis, and diabetes mellitus type II (DM) with osteoporosis). Other results obtained from this research revealed that diabetes mellitus type II (DM) can be considered to be one of the major causes of osteoporosis in the general populatio
Comparison Mechanical Properties of Two Types of Light Weight Aggregate Concrete
This paper presents the behavior of concrete properties by replacing the conventional coarse aggregate used in the concrete mixture by two types of lightweight aggregate; Expanded Perlite Aggregate (EPA) and Volcanic Pumice (VP). To fulfill this aim; three laboratory tests were applied; density, compressive strength, and abrasion resistance, that conducted to extrapolate the range of the changes in the properties of concrete with existence those types of aggregate in the mixture. Also, the volumetric proportion adopted as a strategy for replacing the coarse aggregate by EPA or VP in the concrete mixture. Then, the volumetric proportion ranged from 10% to 50% with the variation step was 10%. Therefore, ten concrete mixtures are prepared and divided into two groups; each group contains five concrete mixes to represent the volumetric replacement (10-50)% of conventional coarse aggregate by EPA or VP. On the other hand, one extra mixture designed by using conventional aggregate (coarse and fine aggregate) without any inclusion of EPA or VP to be considered as a reference mixture. The obtained laboratory results of this study proved that the density, compressive strength, and abrasion resistance readings of concrete decreased at any volumetric proportion replacement of coarse aggregate by EPA or VP. The decrease in density and compressive strength of concrete readings amounted the peak level at 50% replacing of coarse aggregate by EPA, which were 38.19% and 77.37%, respectively than the reference mixture. Additionally, the compressive strength is an important factor affecting the abrasion resistance of concrete mixture, and loss of abrasion decreased as compressive strength increased
Modeling Deflection Control of Reinforced Concrete Slab Systems Using Utility Theory and Sensitivity Analysis
The model presented in this study provides a rational approach to deflection control of
reinforced concrete two way slabs considering uncertainties in structural behavior and deflection limits
and recognizes that the problem is subject to wide and unavoidable variability. Concepts of Monte Carlo
simulation and utility theory are presented. A simulation model taking into account the uncertainties in
materials and loads along with sensitivity analysis of results are presented. Results of simulation
represented in the form of probability density function (PDF) and cumulative density function (CDF),
optimum thickness and results of sensitivity analysis of reinforced concrete two-way slab systems are
presented. This study explores the application of utility theory to the problem because serviceability
failure can occur in structures with adequate safety against collapse, in which the question becomes an
economic issue. In this study, uncertainties in time effects (Creep and shrinkage) are taken into account
by using Monte Carlo simulation and are based on proposed variable parameters taken from major
references
Investigation of a Developed Deflection Control Model of Reinforced Concrete Two Way Slab Systems
A model was presented in a previous study which provided a rational approach to deflection control of reinforced concrete two way slabs considering uncertainties in structural behavior and deflection limits was investigated thoroughly in this work. A simulation model taking into account the uncertainties in materials and loads along with sensitivity analysis of results was developed. Results of simulation represented in the form of probability density function (PDF) and cumulative density function (CDF), optimum thickness and results of sensitivity analysis of reinforced concrete two-way
slab systems were presented. In this study, uncertainties in time effects (Creep and shrinkage) are taken into account by using Monte Carlo simulation and are based on proposed variable parameters taken from major references. In general, the proposed procedure results in smaller thicknesses for two-way slab-beam system than ACI 318-14 recommendations for longer spans and larger thicknesses for shorter spans
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