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Hard Chromium Electroplating and Improvement the Properties by the Thermo Chemical Treatments (Solid Carburizing) of Low Carbon Steel
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In this research the hard chromium electroplating process, which is one of the common methods of overlay coating was used, by using chromium acid as source of chromium and sulphuric acid as catalyst since the ratio between chromic acid and sulphuric acid is (100 : 1) consequently. Plating process was made by applying current of density (40 Amp / dm2) and the range of solution temperature was (50 – 55oC) with different time periods (1-5 hr). A  low carbon steel type (Ck15) was used as substrate for hard chromium electroplating. Solid carburization was carried out for hard chromium plating specimen at temperature (925oC) with time duration (2 hr) to be followed with quenching and tempering. The phase analysis was conducted by using X– ray diffraction. The examination results show that the chromium carbides in plating layer were (Cr23C6, Cr7C3). The microhardness of hard chromium plating specimen was measured, and the results show that the high hardness was about (907HV). After solid carburization the hardness values increase and the results show that the higher hardness for chromium plating layer on low carbon steel surface was (1276 HV).                                                      

      Wear apparatus type (Pin on Disc) was used to study dry sliding  wear properties of low carbon steel (As received) and hard chromium  plating specimens and solid carburized. The effect of applied normal load on wear rate was studied with weighting method using five normal loads (5, 10, 15, 20, 25 N) at constant sliding speed (2.198 m / sec). The results reveal that the wear rate increases with the increasing of applied normal load. A good improvement in wear resistance was noticed for hard chromium plating specimens as compared with substrate specimen. It was also seen that, the improvement in wear resistance was (94%) as compared with substrate metal when carburizing treatment is carried out on hard chromium plating specimens.

 

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Publication Date
Sun Dec 17 2017
Journal Name
Al-khwarizmi Engineering Journal
Effect of Nano Powder on Mechanical and Physical Properties of Glass Fiber Reinforced Epoxy Composite
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Fiber reinforced polymer composite is an important material for structural application. The diversified application of FRP composite has taken center of attraction for interdisciplinary research. However, improvements on mechanical properties of this class of materials are still under research for different applications. In this paper we have modified the epoxy matrix by Al2O3, SiO2 and TiO2 nano particles in glass fiber/epoxy composite to improve the mechanical and physical properties. The composites are fabricated by hand lay-up method. It is observed that mechanical properties like flexural strength, hardness are more in case of SiO2 modified epoxy composite compare to other nano

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Publication Date
Sun Jun 30 2013
Journal Name
Al-khwarizmi Engineering Journal
Effect of Solid Particle Properties on Heat Transfer and Pressure Drop in Packed Duct
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This work examines numerically the effects of particle size, particle thermal conductivity and inlet velocity of forced convection heat transfer in uniformly heated packed duct. Four packing material (Aluminum, Alumina, Glass and Nylon) with range of thermal conductivity (from200 W/m.K for Aluminum to 0.23 W/m.K for Nylon), four particle diameters (1, 3, 5 and 7 cm), inlet velocity ( 0.07, 0.19 and 0.32 m/s) and constant heat flux ( 1000, 2000 and 3000 W/ m 2) were investigated. Results showed that heat transfer (average Nusselt number Nuav) increased with increasing packing conductivity; inlet velocity and heat flux, but decreased with increasing particle size.Also, Aluminum average Nusselt number is about (0.85,2.

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Publication Date
Mon May 22 2023
Journal Name
Al Mustansiriyah Journal Of Pharmaceutical Sciences
Pharmaceutical cocrystal and their role in improving solid state properties of active pharmaceutical ingredients
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Cocrystallization is an emerging approach for improving physico-chemical characteristics of an active pharmaceutical ingredient (API) for instance dissolution rate, solubility, stability in addition to mechanical properties without affecting their therapeutic activity. It is of great importance when other approaches like salt or polymorph formation do not encounter the estimated targets. In this review article, an outline of pharmaceutical cocrystals will be presented, with highlighting on factors affecting cocrystallization which include ∆pKa, donors and acceptors hydrogen bonds, molecular recognition point, synthon forming functional groups flexibility, dicarboxylic acid coformers carbon chain length and solvent effe

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Publication Date
Wed Dec 18 2019
Journal Name
Baghdad Science Journal
Structural and Optical Properties for Nanostructure (Ag2O/Si & Psi) Films for Photodetector Applications
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Ag2O (Silver Oxide) is an important p-type (in chasm to most oxides which were n-type), with a high conductivity semiconductor. From the optical absorbance data, the energy gap value of the Ag2O thin films was 1.93 eV, where this value substantially depends on the production method, vacuum evaporation of silver, and optical properties of Ag2O thin films are also affected by the precipitation conditions. The n-type and p-type silicon substrates were used  with porous silicon wafers to precipitate  ±125 nm, as thick Ag2O thin film by thermal evaporation techniques in vacuum and via rapid thermal oxidation of 400oC and oxidation time 95 s, then characterized by measurement of

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Publication Date
Fri Mar 15 2019
Journal Name
Al-khwarizmi Engineering Journal
Effect Use of Two Chemical Compounds Sodium Nitrate and Sodium Silicate as Corrosion Inhibitor to Steel Reinforcement
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Corrosion of steel reinforcement is one of the biggest problems facing all countries in the world like bridges in the beach area and marine constructions which lead to study these problems and apply some economical solutions. According to the high cost of repair for these constructions, were studied the effect of using kind of chemical compounds sodium nitrite(NaNO2) and sodium silicate(Na2SiO3) as corrosion inhibitors admixture for steel bars that immersed partially in electrolyte solution (water + sodium chloride in 3% conc.) (Approximately similar to the concentration of salt in sea water). The two inhibitors above added each one to the electrolyte solution at concentrations (0.5%, 1% and 2%) for both

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Publication Date
Wed Dec 30 2009
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Drying of solid Materials by vacuum Fluidized Bed Dryer
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In the present study the performance of drying process of dffirent solid materials by batch fluidized bed drying
under vacuum conditions was investigated. Three, different solid materials, namely; ion exchange resin-8528,
aspirin and paracetamol were used. The behavior of the drying curves as well as the rate of drying of these
materials had been studied. The experiments were caried out in a 0.0381 m column diameter fluidized by hot
air under yacuum conditions. Four variables affecting on the rate of drying were studied' these variables are
vacuum pressure (100 - 500 mm Hg), air temperature (303-323 K), particle size (0.3-0.8 mm) and initial
moisture content (0.35-0.55 g/g solid)-for resin and (0.1-0.2 g/g soltid) for a

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Publication Date
Mon Dec 11 2017
Journal Name
Al-khwarizmi Engineering Journal
The Effects of Long-Term Operation and High Temperature on Material Properties of Austenitic Stainless Steel Type 321H
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Changes in mechanical properties of material as a result of service in different conditions can be provided by mechanical testing to assist the estimation of current internal situation of these materials, or the degree of deterioration may exist in furnaces serviced at high temperature and exceed their design life. Because of the rarity works on austenitic stainless steel material type AISI 321H, in this work, ultimate tensile strength, yield strength, elongation, hardness, and absorbed energy by impact are evaluated based on experimental data obtained from mechanical testing. Samples of tubes are extracted from furnace belong to hydrotreaterunit, also samples from un-used tube material are used to make comparisons between these properti

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Publication Date
Fri Sep 21 2018
Journal Name
Materials Research Express
Geometries, electronic properties and stability of molybdenum and tungsten nitrides low-index surfaces
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Motivated by the vital role played by transition metal nitride (TMN) composites in various industrial applications, the current study reports electronic properties, thermodynamic stability phase diagram, and vacancy formation energies of the plausible surfaces of NiAs and WC-type structures of δ3-MoN and δ-WN hexagonal phases, respectively. Low miller indices of various surface terminations of δ3-MoN and δ-WN namely, (100), (110), (111), and (001) have been considered. Initial cleaving of δ3-MoN bulk unit cell offers separate Mo and N terminations signified as δ3-MoN (100): Mo, δ3-MoN(100):N, δ3-MoN(111):Mo, δ3-MoN(111):Mo, and δ3-MoN(001):Mo. However, the (110) plane reveals mix-truncated with both molybdenum and nitrogen atoms i

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Publication Date
Tue Jan 09 2018
Journal Name
World Rural Observations
Solid cartridges in Determination of Benzidines in River and Wastewater by HPLC
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A solid Phase Extraction (SPE) cartridges followed by HPLC-UV method is described for the simultaneous quantitative determination of benzidine (BZ) and its substituted 3, 3’-dichlorobenzidine (DCB) and 3, 3’-Dimethylbenzidine (DMB). The Benzidines were separated by liquid chromatography using a C-18 column with UV detector at wave length of 280nm. The mode of Flow was isocratic. The mobile phase was consisted of 75:25 methanol: water, column temperature 50C°, and Flow Rate 1.8ml/min. Calibration curves were linear (R2 = 0.9979-0.9995). LOD (26.36-33.67) µg/L, LOQ (109.98-186.11) µg/L, the Robustness (2.99-4.35), Ruggedness (2.93-3.65).Conditions of extraction by (SPE) cartridges were optimized, the resin used is Octadecyl silica (ODS

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Publication Date
Tue Jun 20 2023
Journal Name
Baghdad Science Journal
Visible-Light-driven Photocatalytic Properties of Copper(I) Oxide (Cu2O) and Its Graphene-based Nanocomposites
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In this study, an improved process was proposed for the synthesis of structure-controlled Cu2O nanoparticles, using a simplified wet chemical method at room temperature. A chemical solution route was established to synthesize Cu2O crystals with various sizes and morphologies. The structure, morphology, and optical properties of Cu2O nanoparticles were analyzed by X-ray diffraction, SEM (scanning electron microscope), and UV-Vis spectroscopy. By adjusting the aqueous mixture solutions of NaOH and NH2OH•HCl, the synthesis of Cu2O crystals with different morphology and size could be realized. Strangely, it was found that the change in the ratio of de-ionized water and NaOH aqueous solution led to the synthesis of Cu2O crystals of differen

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