670 research outputs found
Structural, Morphological and Optical Parameters of Zn(1-x) CuxS Thin Films for Optoelectronic Devices
In the present work, ZnS and Cu incorporated at (2%, 4%,6%, 8%, and 10%) thin films were growth onto hot glass substrates at substrates temperature 270 oC with thickness about 100 nm by chemical spray pyrolysis technique. The solutions of the spray consists of Zn(CH3COO)2.2H2O, SC(NH2)2 and CuCl2.2H2O with molar concentration 0.1M/L. The structure of the film was studied by XRD pattern, the results shows that the films were polycrystalline with cubic phase for pure ZnS and hexagonal phase for Zn1-xCuxS at x=10%. The optical constants, refractive index, n and extinction coefficient, k were determined The optical energy gap of the direct transition is also estimated, pure ZnS is 3.42 eV, and it increases as the Cu concentration increases from 3.49 to 3.67 eV. The room temperature photoluminescence (PL) of copper-doped zinc sulfide (ZnS:Cu) nanoparticles was studied. Through Gaussian fitting, the PL spectrum of undoped ZnS nanoparticles is deconvoluted into two blue luminescence peaks (centered at 411 nm and 455 nm, respectively), both of which can be attributed to the recombination of ZnS defect states. But for doped samples, a third peak at about 500 nm was also identified. Discussed the changes of all optical constants and PL spectra from the changes of optoelectronics microstructure parameter
The Impact of Competencies, Risk Management and Auditors Interactions on Internal Audit Effectiveness in Libyan Commercial Banks
Internal audit (IA) has become an important and integral function of organizations in achieving their objectives and protecting their assets. Nonetheless, IA effectiveness has received scant attention in the literature, especially in the context of developing countries such as Libya. The research aimed To analyze the impact of competencies of the internal audit team, risk management and interaction between internal auditors and audit committees on internal audit effectiveness in Libyan commercial banks. The research used the quantitative methodology for analysis.the sampling technique used in this research was random sampling. Participants in research included 105 auditors selected from branches of commercial banks in Libya. The research adopted the descriptive method using the survey from the commercial banks and its branches and analysing the impact of competencies, rick managment and auditors interection on internal audit effectivness. The results of this research showed that: firstly; Competencies of an Internal Audit team on Internal audit effectiveness was significant and positive correlation. Secondly; Risk management on Internal audit effectiveness was higer significant and positive correlation. Thirdly; Interaction between IA and AC on Internal audit effectiveness was significant and positive correlation
Rice Bran as an Alternative Feedstuff in Broiler Nutrition and Impact of LiposorbĀ® and Vitamin E-Se on Sustainability of Performance, Carcass Traits, Blood Biochemistry, and Antioxidant Indices
The impact of dietary rice bran with or without feed additives on the performance, carcasses, and blood profiles of chickens was examined. A total of 245 unsexed one-week-old broiler chicks were divided into seven groups, with seven replications of five chicks each. The treatments were: (1) control, (2) 5% rice bran, (3) 5% rice bran + 0.5 g/kg of LiposorbĀ®, (4) 5% rice bran + 1 g/kg of vitamin E-Se, (5) 10% rice bran, (6) 10% rice bran + 0.5 g/kg LiposorbĀ®, and (7) 10% rice bran + 1 g/kg of vitamin Eāselenium. Considering the entire experimental period, it did not affect the in vivo performance of the broilers. However, all the experimental diets decreased dressing % compared with the control (p < 0.01) and the worst values were obtained for the 10% RB groups (75.7, 75.9, and 75.8%, respectively, for 10%RB, 10%RB + Liposorb, and 10%RB + Vit. E-Se groups). All the experimental diets decreased (p < 0.01) the albumin/globulin ratio due to an increased level of serum globulins. Differences in lipid profiles, antioxidants, and immunity parameters in plasma were not related to dietary treatments. In conclusion, the use of rice bran up to 10% in diets had no harmful effect on the overall growth performance of the broilers from 1 to 5 weeks of age. Still, carcass characteristics were negatively affected, except for heart percentage. In addition, the supplementation of LiposorbĀ® or vitamin E-Se to rice bran diets did not recover these harmful effects. Thus, rice bran could be utilized at 10% in broiler diets when growth performance was considered; further research is required
Femtosecond Laser Induced Structural Dynamics and Melting of Cu (111) Single Crystal. An Ultrafast Time-Resolved X-Ray Diffraction Study
Femtosecond, 8.04 keV x-ray pulses are used to probe the lattice dynamics of a 150 nm Cu (111) single crystal on a mica substrate irradiated with 400 nm, 100 fs laser pulses. For pump fluences below the damage and melting thresholds, we observed lattice contraction due to the formation of a blast force and coherent acoustic phonons with a period of ā¼69 ps. At larger pump fluence, solid to liquid phase transition, annealing, and recrystallization were measured in real time by monitoring the intensity evolution of the probing fs x-ray rocking curves, which agreed well with theoretical simulation results. The experimental data suggest that the melting process is a purely thermal phase transition. This study provides, in real time, an ultrafast time-resolved detailed description of the significant processes that occur as a result of the interaction of a femtosecond light-pulse with the Cu (111) crystal surface. Published by AIP Publishing. [http://dx.doi.org/10.1063/1.4975198
Production of Aspergillus quadrilineatus MT083999 Chitinase, Ī²-1,3-Glucanase and Nano-silver Important for Biocontrol of Fusarium spp. Infecting Crops
416-425In our search for an active biocontrol agent against Fusarium solani and F. oxysporum, the major species causing wilt, root
rot and damping-off in plants affecting crops. The fungal isolate genetically identified as Aspergillus quadrilineatus MT083999
displayed high antagonistic activities against the tested root-rot fungi, and presented valuable chitinase and Ī²-glucanase
activities of 235.484 and 508.953 U/gds, respectively. Solid state fermentation conditions were optimized by applying 20 trails
of the central composite design (Three-factor-five-level) and two responses of chitinase R1 and Ī²-glucanase R2 activities,
respectively. The optimum activities of chitinase (386.70 U/gds) and Ī²-glucanase (1094.70 U/gds) were obtained in trial 4 and 2
respectively, with about 1.64-fold increase in chitinase activity and 2.15-fold increase in Ī²-glucanase activity when compared
with initial fermentation. Biosynthesis of nano-silver from A. quadrilineatus was evaluated in 10 experiments of another design
of 2-factors-5-levels. The antifungal effects of each biosynthesized nano-silver against F. solani (R1) and F. oxysporum (R2)
were evaluated as Inhibition Zone Diameter (IZD).The high fungicide nano-silver against both tested phytopathogens was
characterized by UV-visible spectrophotometry, Transmission Electron Microscopy (TEM), Zeta Dynamic Light Scatter (DLS)
and Fourier Transform Infrared Spectroscopy (FTIR). The results indicated that A. quadrilineatus MT083999 chitinolytic
enzymes and nano-silver can be applied as a novel candidate in biocontrol of Fusarium wilt infecting crops worldwide
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A study on the influencing parameters in developing construction and demolition waste-based geopolymer concretes and their sustainability assessment
YesConstruction and demolition waste (CDW) has been recently identified as a potential aluminosilicate source for geopolymers. However, the available research has mainly focused on developing CDW-based geopolymer pastes and mortars, while studies on geopolymer concretes sourced from CDW have been very limited. Thus, the current study aimed at experimentally identifying different CDW materials suitable for producing geopolymer concretes. Additionally, the study analysed the mechanical, microstructural, and environmental properties of CDW- based geopolymer concrete produced. In this regard, the effect of relevant parameters on the compressive strength development of CDW-based geopolymer concretes was comprehensively investigated, including those related to precursor types/fineness, alkali activator solution, aggregate type/size and curing regimes. Microstructural analyses were also conducted on the selected samples (100% brick waste, 100% tile waste, 100% concrete waste and 75% brick waste + 25% GGBS). Finally, the environmental impact of geopolymer concrete was assessed and compared with similar traditional concrete. Results showed that employing CDWs alone is not suitable to achieve sufficient strengths under all curing regimes. However, the inclusion of 25% GGBS significantly improved the strength performance of CDW-based geopolymer concrete, in comparison to other supplementary cementitious materials (SCMs) such as Class-C fly ash and calcium hydroxide. The particle size of CDWs and concentration of alkaline activators highly affect the performance of CDW-based geopolymer concretes. Utilization of CDWs with particles finer than 75 Ī¼m and high concentrations of NaOH (12 M) is recommended to achieve good performance. The results also indicate that almost similar energy is needed for producing CDW-based geopolymer and OPC-based traditional concrete, whereas a huge reduction in CO2 emission (ā¼40%) was estimated in the case of geopolymers. The outcomes of the current study are expected to contribute to the advancement of geopolymer concrete derived from CDW in addition to providing valuable insights into this type of concrete for practitioners and academics
Black soldier fly (Hermetia illucens) meal as a promising feed ingredient for poultry: A comprehensive review
Insects could be a potential replacement of proteinārich ingredients in poultry diets. Among these insects, black soldier fly (BSF), Hermetia illucens, has a high content of protein and fat, which reinforces the potential of using it in poultry feed formulation and makes it one of the most promising insect species for commercial production. Protein content as well as amino acid profile in H. illucens larvae is comparable to those in many proteinārich feedstuffs such as fish meal and soybean meal. BSF can convert organic wastes into a precious source of nutrients, such as proteins, lipids, and chitin, which contribute to reducing the environmental burden and pollution potential arising from organic waste accumulation. This review emphasizes the significance of this insect as a āgreenā technology in the extremely variable recycling of organic waste and generates a sustainable protein source as well as the importance of its use as a substitute of proteinārich feedstuff in poultry feed manufacturing
Femtosecond Laser Induced Structural Dynamics and Melting of Cu (111) Single Crystal. An Ultrafast Time-Resolved X-Ray Diffraction Study
Femtosecond, 8.04 keV x-ray pulses are used to probe the lattice dynamics of a 150 nm Cu (111) single crystal on a mica substrate irradiated with 400 nm, 100 fs laser pulses. For pump fluences below the damage and melting thresholds, we observed lattice contraction due to the formation of a blast force and coherent acoustic phonons with a period of ā¼69 ps. At larger pump fluence, solid to liquid phase transition, annealing, and recrystallization were measured in real time by monitoring the intensity evolution of the probing fs x-ray rocking curves, which agreed well with theoretical simulation results. The experimental data suggest that the melting process is a purely thermal phase transition. This study provides, in real time, an ultrafast time-resolved detailed description of the significant processes that occur as a result of the interaction of a femtosecond light-pulse with the Cu (111) crystal surface. Published by AIP Publishing. [http://dx.doi.org/10.1063/1.4975198
Axial behavior of reinforced concrete short columns strengthened with wire rope and T-shaped steel plate units.
yesThis paper presents a relatively simple column strengthening procedure using unbonded wire rope and T-shaped steel plate units. Twelve strengthened columns and an unstrengthened control column were tested to failure under concentric axial load to explore the significance and shortcomings of the proposed strengthening technique. The main variables investigated were the volume ratio of wire ropes as well as geometrical size and configuration of T-shaped steel plates. Axial load capacity and ductility ratio of columns tested were compared with predictions obtained from the equation specified in ACI 318-05 and models developed for conventionally tied columns, respectively. The measured axial load capacities of all strengthened columns were higher than predictions obtained from ACI 318-05, indicating that the ratio of the measured and predicted values increased with the increase of volume ratio of wire ropes and flange width of T-shaped steel plates. In addition, at the same lateral reinforcement index, a much higher ductility ratio was exhibited by strengthened columns having a volume ratio of wire ropes above 0Ā·0039 than tied columns. The ductility ratio of strengthened columns tested increased with the increase of flange width, thickness, and web height of T-shaped steel plates. A mathematical model for the prediction of stressāstrain characteristics of confined concrete using the proposed strengthening technique is developed, that was in good agreement with test results
Window opening effects on structural behaviour of historical masonry Fatih Mosque
YesStructural walls of old historical structures are either blind or have openings for functional requirements. It is well known that in and out of plane responses of structural walls are affected by the size, locations, and arrangements of such openings. The purpose of this investigation is to study the window opening effects on static and seismic behaviors of historical masonry old mosques. Fatih Mosque, which was converted from a church, constructed in 914 in Trabzon, Turkey, is selected for this purpose. The mosque is being restored. Structural exterior walls of the mosque were made using stone and mortar materials. When the plaster on the walls was removed during the restoration, 12 window openings were found as blind on the exterior structural walls of the mosque. Within the scope of restoration works, it is aimed to open such blind windows. In order to investigate the effects of the window openings on the structural behavior of the mosque, 3D solid and finite elements models of the mosque with and without window openings are initially developed. The experimental dynamic characteristics such as frequency, damping ratio, and mode shapes of the current situation of the mosque, where some windows openings are blind, are determined using Ambient Vibration Testing. Then, the finite element model of the current situation of the mosque is updated using the experimental dynamic characteristics. The static and seismic time history analyses of the updated finite element model with and without window openings are carried out. Structural behaviors of the mosque with and without window openings are compared considering displacement and stress propagations
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