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Spectral Properties, Reconstitution and Kinetics of Paracoccous denitrificans Isovaleryl-CoA Dehydrogenase
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Isovaleryl CoA dehydrogenase (IVDH) is a flavoprotein that introduce a trans-double bond between C2 and C3 of the isovaleryl CoA substrate, an intermediate in leucine catabolism pathway. Interrogation of the Paracoccus denitrificans Pd1222 genome has identified Pden_3633 gene as a candidate to encode for IVDH. In previous study by Rafid et al (under the publishing), this putative IVDH was expressed in E. coli and purified as N-terminal Strep-tagged protein. In current study, spectral properties of the purified IVDH were conducted and the results showed that the enzyme was obtained as an apoprotein. For this reason, IVDH has been reconstituted by incubation with flavin adenine dinucleotide (FAD) and the experiment showed that the ratio 1: 20% (IVDH: FAD molar excess) was achieved fully reconstitution. Furthermore, kinetic parameters of the reconstituted IVDH were studied and the enzyme exhibited a specific activity for isovaleryl-CoA substrate while Vmax and KM were estimated to be 600 mU mg-1 and 7.13 μM respectively. Finally, gel filtration by using HiLoad 16/60 Superdex 200 column was performed to investigate the quaternary structure of the recombinant IVDH. An apparent molecular weight of 171640 Da was determined.

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Publication Date
Mon Jan 01 2024
Journal Name
Open Engineering
Effect of nano-TiO<sub>2</sub> on physical and rheological properties of asphalt cement
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Abstract<p>In recent years, nano-modified asphalt has gained significant attraction from researchers in the design of asphalt pavement fields. The recently discovered Titanium dioxide nanoparticles (TiO<sub>2</sub>) are among the most exciting and promising nanomaterials. This study examines the effect of 1, 3, 5, and 7% of nano-TiO<sub>2</sub> by weight of asphalt on some of its rheological and hardened properties. The experimental study included physical and rheological properties. The asphalt penetration, softening point, ductility, and rotational viscometer tests indicate that 5% nano-TiO<sub>2</sub> is the ideal amount to be added to bitumen as a modifier. The </p> ... Show More
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Publication Date
Tue Nov 14 2023
Journal Name
International Journal Of Dentistry
Antimicrobial Efficiency of Hypochlorous Acid and Its Effect on Some Properties of Alginate Impression Material
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Dental clinicians and professionals need an affordable, nontoxic, and effective disinfectant against infectious microorganisms when dealing with the contaminated dental impressions. This study evaluated the efficiency of hypochlorous acid (HOCl) as an antimicrobial disinfectant by spraying technique for the alginate impression materials, compared with sodium hypochlorite, and its effect on dimensional stability and reproduction of details. HOCl with a concentration of 200 ppm for 5 and 10 min was compared with the control group (no treatment) as a negative control and with sodium hypochlorite (% 0.5) as a positive control. Candida albicans, Staphylococcus aureus, and Pseudomonas aeruginosa were selected to assess the antimicrobi

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Publication Date
Tue Apr 02 2024
Journal Name
Iraqi Journal Of Applied Physics
Effect of Substrate Temperature on Characteristics and Gas Sensing Properties of Nb2O5/Si Thin Films
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Thin films of Nb2O5 have been successfully deposited using the DC reactive magnetron sputtering technique to manufacture NH3 gas sensors. These films have been annealed at a high temperature of 800°C for one hour. The assessment of the Nb2O5 thin films structural, morphological, and electrical characteristics was carried out using several methods such as X-ray diffraction (XRD), atomic force microscopy (AFM), energy-dispersive X-ray spectroscopy (EDS), Hall effect measurements, and sensitivity assessments. The XRD analysis confirms the polycrystalline composition of the Nb2O5 thin films with a hexagonal crystal structure. Furthermore, the sensitivity, response time, and recovery time of the gas sensor were evaluated for the Nb2O5 thin film

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Publication Date
Tue Apr 05 2022
Journal Name
Nano Hybrids And Composites
Structural and Optical Properties of ZnO Nanostructures Synthesized by Hydrothermal Method at Different Conditions
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Zinc oxide (ZnO) nanoparticles were synthesized using a modified hydrothermal approach at different reaction temperatures and growth times. Moreover, a thorough morphological, structural and optical investigation was demonstrated using scanning electron microscopy (SEM), x-ray diffraction (XRD), ultra-violate visible light spectroscopy (UV-Vis.), and photoluminescence (PL) techniques. Notably, SEM analysis revealed the occurrence of nanorods-shaped surface morphology with a wide range of length and diameter. Meanwhile, a hexagonal crystal structure of the ZnO nanoparticles was perceived using XRD analysis and crystallite size ranging from 14.7 to 23.8 nm at 7 and 8 ℎ𝑟𝑠., respectively. The prepared ZnO samples showed good abso

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Publication Date
Sat Dec 04 2021
Journal Name
Transportation Research Record: Journal Of The Transportation Research Board
Gradation Effects on Strength and Deformation Properties of High-Quality Crushed Rock Base Materials
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The importance of specifying proper aggregate grading for achieving satisfactory performance in pavement applications has long been recognized. To improve the specifications for superior performance, there is a need to understand how differences in aggregate gradations within the acceptable limits may affect unbound aggregate base behavior. The effects of gradation on strength, modulus, and deformation characteristics of high-quality crushed rock base materials are described here. Two crushed rock types commonly used in constructing heavy-duty granular base layers in the State of Victoria, Australia, with three different gradations each were used in this study. The gradations used represent the lower, medium, and upper gradation li

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Publication Date
Sat Apr 09 2022
Journal Name
Engineering, Technology &amp; Applied Science Research
The Mechanical Properties of Fly Ash and Slag Geopolymer Mortar with Micro Steel Fibers
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In this study, experimental mortar combinations with 1% micro steel fibers, were examined to create geopolymer mortars. To test the effect of the fibers on the mortar's resistance, the geopolymer mortar was designed with various proportions of more environmentally friendly materials fly ash and slag. The percentage of fly ash by weight was 50, 60, and 70% of the slag. The best results were obtained when a 50:50 ratio of fly ash and slag were mixed with 1% micro steel fibers. The results showed that the mixtures containing fibers performed better in the considered tests (toughness index, ductility index, and resilience index). In the impact resistance test, the mixture contained 50% fly ash by weight of the slag with a temperature of

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Publication Date
Thu Dec 29 2016
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Structural and Electrical Properties Dependence on annealing temperature of a-Ge:Sb/c-Si Heterojunction
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 In this work, we are Study the effect of annealing temperature on the structure of a-Ge films doped with Sb and the electrical properties of a-Ge:Sb/c-Si heterojunction fabricated by deposition of a-Ge:Sb film on c-Si by using thermal evaporation. Electrical properties of aGe:Sb/c-Si heterojunction include I-V characteristics in dark at different annealing temperatures and C-V characteristics and with the C-V characteristics suggest that the fabricated heterojunction was abrupt type, built in potential determined by extrapolation from 1/C2-V curve and show that the built - inpotential (Vbi) for the Ge:Sb/Si system increases with the increase of annealing temperatures

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Publication Date
Sun Dec 06 2009
Journal Name
Baghdad Science Journal
Preparation of Electrical Conducting Polymer CompositesFrom Polyvinylchloride (PVC) Resin and StudyingSome its Electrical Properties
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The D.C electrical and thermoelectrically properties of randomly mixed isolator – electrolyte system as (Al/ PVC – LiF/Al) junction consisting of polyvinyl chloride (PVC)resin reinforced with Lithium Fluoride (LiF) powder were studied. A comparison is made the properties of (PVC) material with varying percentage of (LiF) powder (0%, 30%, 50%, 80%)to find out the effect of reinforcement of isolator material. The composites dissolving in 10ml form tettraHaedroflourn (THF) and Solution were the castled in Petri dish and Laved it dry in the air, The out coming Sample were disc - Like shape of a diameter of about 3cm and thickness reneged between (0.01- 0.018) cm . The composites dissolving in 10ml form tettraHaedroflourn (THF) a

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Publication Date
Sun Mar 07 2010
Journal Name
Baghdad Science Journal
Structural and Optical Properties of SnS2:Cu Thin films prepared by chemical Spbay Pyrolysis
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Thin filis have been prepared from the tin disulphide (SnS2 ), the pure and the doped with copper (SnS2:Cu) with a percentages (1,2,3,4)% by using ahemical spray pyrolysis techniqee on substrate of glass heated up to(603K)and sith thicknesses (0.7±0.02)?m ,after that the films were treated thermally with a low pressure (10-3mb) and at a temperature of (473K) for one hour. The influence of both doping with copper and the thermal treatment on some of the physical characteristics of the prepared films(structural and optical) was studied. The X-ray analysis showed that the prepared films were polycrystalline Hexagonal type. The optical study that included the absorptance and transmitance spectra in the weavelength range (300-900)nm

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Publication Date
Fri Jan 01 2016
Journal Name
Journal Of Engineering
Some Properties of Polymer Modified Self-Compacting Concrete Exposed to Kerosene and Gas Oil
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This thesis aims to study the effect of addition polymer materials on mechanical properties of self-compacting concrete, and also to assess the influence of petroleum products (kerosene and gas oil) on mechanical properties of polymer modified self-compacting concrete (PMSCC) after different exposure periods of (30 ,60 ,90 ,and 180 days).

Two type of curing are used; 28 days in water for SCC and 2 days in water followed 26 days in air for PMSCC.

The test results show that the PMSCC (15% P/C ratio) which is exposed to oil products recorded a lower deterioration in compressive strength's values than reference concrete. The percentages of reduction in compressive strength values of PMSCC (15% P/C ratio) was

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