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bsj-2697
Study of Some Physical and Chemical Properties of Staphylolysin Enzyme purified from Pseudomonas aeruginosa
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Some of the characters of the Staphylolysin A and D enzymes purified from Pseudomonas aeruginosa P16 and P5 respectively were studied, the molecular weights of Staphylolysin A and D were 20.417 kilo dalton and 23.988 kilo Dalton respectively by SDS- polyacryl amide gel electrophoresis. The optimum pH for staphylolysin A activity was found to be 8 which gives higher activity reaches 150 unit/ml, and for enzyme stability was 7.5-8.5 in which the enzyme nearly retained its full activity, while it was 9.5 for staphylolysin D that gives higher activity of 16 unit/ml,and 8.5-9.5 for enzyme stability in which the enzyme nearly retained its full activity, Maximum activity of two enzymes was obtained at 40C in which the specific activity for staphylolysin A and D were 140 and 16.4 unit/ml, and the two enzymes remained approximately without change at 25-40C for one hour. When the effects of some materials on Staphylolysin A&D activity were studied, the results showed that both sodium chloride & potassium chloride at 1 & 5 mM had the activator effect on enzymatic activity compared with its control where the staphylolysin A and D retained 105% ,108% and 102%, 104% of their activity respectively when treated with sodium chloride, while they retained 110%, 114% and 133%, 118% of their activity respectively when treated with potassium chloride. The enzymatic activity for both enzymes were inhibited when treated with ferric , mercury and zinc chloride at variable ratios, Staphylolysin A kept 73% and 7% of its initial activity respectively when treated with 5mM of ferric chloride and mercury chloride respectively and it kept only 9% of its initial activity when treated with 0.1mM Zinc chloride . Staphylolysin D kept 45% and 13% of it is initial activity respectively when treated with 5mM of ferric chloride and mercury chloride respectively and it kept only 23% of its initial activity when treated with 0.1mM Zinc chloride while enzymatic activity for both enzymes were not affected when treated with EDTA at l0mM and phenyl methyl sulphonyl fluoride (PMSF) at 0.4mM.These results referred to that Staphylolysin A and D are Zn -metallo endopeptidase .

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Publication Date
Sat Feb 10 2018
Journal Name
Al-nahrain Journal For Engineering Sciences
Properties of Epoxy-Asphalt Pavement Mixture for Bridge Decks
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Improving the ability of asphalt pavement to survive the heavily repeated axle loads and weathering challenges in Iraq has been the subject of research for many years. The critical need for such data in the design and construction of more durable flexible pavement in bridge deck material is paramount. One of new possible steps is the epoxy asphalt concrete, which is classified as a superior asphalt concrete in roads and greatly imparts the level of design and construction. This paper describes a study on 40-50 penetration graded asphalt cement mixed with epoxy to produce asphalt concrete mixtures. The tests carried out are the Marshall properties, permanent deformation, flexural fatigue cracking and moisture damage. Epoxy asphalt mixes perf

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Publication Date
Mon Feb 01 2021
Journal Name
Iop Conference Series: Materials Science And Engineering
The influence of incorporating recycled brick on concrete properties
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Abstract<p>One of the major problems in modern construction is the accumulation of construction and demolition waste; this study thus examines the consumption of waste brick in concrete based on the use of blended nano brick powder as replacement for cement and as a fine aggregate. Seven concrete mixes were developed according to ACI 211.1 using recycled waste brick. Nano powder brick at 0, 5, and 10% was used as a replacement by cement weight, with other mixes featuring 10, 20, and 30% partial replacement by volume of river sand with brick. The experimental results for replacement of cement with nano brick powder showed an enhancement in mechanical properties (compressive, flexural, and tensile strength) at 7,</p> ... Show More
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Publication Date
Fri Apr 01 2022
Journal Name
Digest Journal Of Nanomaterials And Biostructures
The structural properties of Y1-XLaXBa4Cu7O15+ δ superconductor compound
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The eff ect of partial substitution for lanthanum (La) on the structural properties of the compound Y1-xLaxBa4Cu7O15+δ were studied. The variation of (x) are x=0.1, 0.2 and 0.3, which was synthesized by solid state reaction method. The mixed powder was pressed with pressure (7 ton / cm2) as a disc (1.5 cm) diameter and a thickness of (0.25 to 0.3 cm). The samples were sintering by 120 °C / hour with a changing rate from room temperature to 850 ° C through 72 hours. XRD analysis using to calculate crystal size, strain and degree of crystallinity. It was found all samples have orthorhombic structure and change of structure with increasing lanthanum concentration. It was shown that the change lanthanum concentrations of all our samp

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Publication Date
Wed Mar 10 2021
Journal Name
Baghdad Science Journal
the effect of doping ratio on the opical properties
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the films of cdse pure and doped with copper ratio glass substrate effect od cucomcentration technique thikness doped with copper is an anonmg and the density of state increases

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Publication Date
Wed Nov 01 2017
Journal Name
Journal Of Engineering
Development the Mechanical Properties of (AL-Li-Cu) Alloy
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The aim of this research is to develop mechanical properties of a new aluminium-lithium-copper alloy. This alloy prepared under control atmosphere by casting in a permanent metal mould. The microstructure was examined and mechanical properties were tested before and after heat treatment to study the influence of heat treatment on its mechanical properties including; modulus of elasticity, tensile strength, impact, and fatigue. The results showed that the modulus of elasticity of the prepared alloy is higher than standard alloy about 2%. While the alloy that heat treated for 6 h and cooled in water, then showed a higher ultimate tensile stress comparing with as-cast alloy. The homogenous heat treatment gives best fatigue

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Publication Date
Tue Dec 15 2020
Journal Name
Technologies And Materials For Renewable Energy, Environment And Sustainability: Tmrees20
Studying properties of propagated transverse modes through optical fibers
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Publication Date
Sat Jun 01 2019
Journal Name
Geoderma
Effect of cover crop management on soil hydraulic properties
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Publication Date
Fri Feb 04 2022
Journal Name
Neuroquantology
Studying Optical Properties of Quantum Dot Cylindrical Fresnel Lens
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An optical system including quantum dot cylindrical Fresnel lens (CFL) has been designed by using Zemax optical designing program. Quantum dot cylindrical Fresnel lens has a relatively small thickness compared to conventional lenses and high absorbance. It contains grooves in the form of parallel lines, and each groove represents an individual lens that works to change the path of light falling on it to a single focal line. (CFL) is characterized by its small focal length despite its large area and small thickness, due to the nature of its design that gives this feature, which is applied in many optical systems (imaging and non- imaging system). In this paper, the visual properties of the (CFL) were studied as it is one of the impor

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Publication Date
Mon Jun 30 2003
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Interfacial Rheological Properties of Iraqi Crude Oils Water System
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Publication Date
Sun Nov 01 2020
Journal Name
Journal Of Engineering
Hydrated Lime Effects on Geotechnical Properties of Clayey Soil
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Cohesive soils present difficulties in construction projects because it usually contains expansive clay minerals. However, the engineering properties of cohesive soils can be stabilized by using various techniques. The research aims to elaborate on the influences of using hydrated lime on the consistency, compaction, and shear strength properties of clayey soil samples from Sulaimnai city, northern Iraq. The proportions of added hydrated lime are 0%, 2.5%, 5%, 7.5% and 10% to the natural soil sample. The results yielded considerable effects of hydrated lime on the engineering properties of the treated soil sample and enhancement its strength. The soil's liquid limit, plasticity index, and optimum moisture content were de

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