Unlike welding, soldering does not involve melting the work pieces. Soldering is a process in which two or more items are joined together by melting and putting a filler metal (solder) into the joint. Failure in the solder joint may make the system components lose their functions. Electrical wiring and electronic components are joined to devices and printed circuit boards using soldering. Soldering and brazing are both used in the assembly of musical instruments. Lead-tin alloy solder employed in the current investigation which has a diameter of 4 mm and a density of 11.0103 kg/m3 with continuous heat flux heating from the domain's left side and complete insulation on the other side. The melting of PCM was simulated using the ANSYS (Fluent) melting model. Three procedures were followed during the heating stage of the reflow process to perform the melting heat-transfer analysis. The simulation's results were recorded at regular intervals of 15 seconds. The results show melting rate increases as time proceeds. It is almost the same at the initial stages and increases in the middle and the end of the melting process. Heat transfer happens mostly through conduction during the first 0–30 seconds of the melting process, changing to natural convection as the material continues to heat up.
The reinforced fiberglass in cement slurry reflects the effect on its properties compared to usual additives. Fiberglass is typically used in cement slurry design for one or another of the following goals: (Earth earthquake, bearing storage, and with differential stresses, to enhance cement durability and increase its compressive strength). The main goal is to use glass fiber and ground fiberglass to improve the tensile strength and moderate compressive strength significantly. On the other hand, the use of glass fibers led to a slight increase in the value of thickening time, which is a desirable effect. Eleven glass fiber samples and milled glass fiber were used to show these materials' effect on Iraqi cement with (0.125, 0.25, 0.5
... Show MoreIn this work dithine complexes prepared from dithiol benzil ligand and central ion to the Ni,Pd,Pt, element the ligand and complexes have been investigated using FTIR spectrophotometer and uv-vis-NIR spectral reigns show higher intensity represents the ?-?* transition in the chromopher cycle .These absorption which appear in visible and near IR spectral regions ,According to the complexes of one group ,the spectral shifting due to the change of central ion has been found to be related to atomic number of central ion .This shifting is increased while decreasing the central ion atom number These complexes have been implemented in Nd+2:YAG cavity because each posses resonant absorption band near Nd+2:YAG, Nd+2:Glass emitting at (106
... Show MoreThis study aims to determine the impact of organization values as an independent variable across its dimensions (organization management values, organization mission values, relations management values, and environment management values) on achieve the strategic success which is the dependent variable and include its dimensions (environmental analysis, creative thinking, strategic decision, effective implementation, and leadership capacities). The study is conducted in the Iraq Oil Ministry. It deployed the analytical descriptive approach. It focuses on the study problem enquiries throughout addressing several principal and sub-hypothesizes in regards to cause and effect relationship. To achieve this result
... Show MoreThis research includes problems that facing the philosophy of education in the variables of knowledge and Informatics society (techno _ social).
The problematic research included three questions:
1- What are the concepts and characterization related to the problematic of relationship between the philosophy of education and informatics variables (techno - social).
2-What kind of problems facing speech philosophy of education in the variables information (techno - social)
3 - What are the perceptions of educational proposed to address problematic philosophy of education in the scope of human (human nature) and (values and morals), in addition the research may explain the co
... Show MoreThis work was conducted to study the treatment of industrial waste water, and more particularly those in the General Company of Electrical Industries.This waste water, has zinc ion with maximum concentration in solution of 90 ppm.
The reuse of such effluent can be made possible via appropriate treatments, such as chemical coagulation, Na2S is used as coagulant.
The parameters that influenced the waste water treatment are: temperature, pH, dose of coagulant and settling time.
It was found that the best condition for zinc removal, within the range of operation used ,were a temperature of 20C a pH value of 13 , a coagulant dose of 15 g Na2S /400ml solution and a settling time of 7 days. Under these conditions the zinc concentrat
What distinguishes human rights issues is their importance to the international community and their importance to democratic political regimes, because they are the axis of any political regime that seeks to achieve a successful democratic path and a stable state. So, countries that are interested in human rights try to enshrine those rights and freedoms in their constitutions and reinforce their concepts in their laws and legislations. Not to mention its involvement in international conventions and treaties concerned with human rights and freedoms, and this is what the Sultanate of Oman has worked on and confirm in the provisions of its 1996 constitution and its amendments
This study was conducted at the Research Experimental Station of the College of Agricultural Engineering/University of Baghdad in the Al-Jadiriyah area during the autumn season of 2022. The study aimed to investigate the effect of phosphorus addition and zinc spraying on the nutrient content and root growth of the cabbage. The experiment included two factors: the first factor was phosphorus with four concentrations (P25%, P50%, P75%, and P100%) of the recommended complete fertilizer dose (135 kg P2O5 per hectare), and the second factor was zinc spraying with three concentrations (0, 30, and 60 mg.L-1) of zinc sulfate (ZnSO4). The results showe
This paper investigated the treatment of textile wastewater polluted with aniline blue (AB) by electrocoagulation process using stainless steel mesh electrodes with a horizontal arrangement. The experimental design involved the application of the response surface methodology (RSM) to find the mathematical model, by adjusting the current density (4-20 mA/cm2), distance between electrodes (0.5-3 cm), salt concentration (50-600 mg/l), initial dye concentration (50-250 mg/l), pH value (2-12 ) and experimental time (5-20 min). The results showed that time is the most important parameter affecting the performance of the electrocoagulation system. Maximum removal efficiency (96 %) was obtained at a current density of 20 mA/cm2, distance be
... Show MoreBackground: This in vitro study measure and compare the effect of light curing tip distance on the depth of cure by measuring vickers microhardness value on two recently launched bulk fill resin based composites Tetric EvoCeram Bulk Fill and Surefil SDR Flow with 4 mm thickness in comparison to Filtek Z250 Universal Restorative with 2 mm thickness. In addition, measure and compare the bottom to top microhardness ratio with different light curing tip distances. Materials and Method: One hundred fifty composite specimens were obtained from two cylindrical plastic molds the first one for bulk fill composites (Tetric EvoCeram Bulk Fill and Surefil SDR Flow) with 4 mm diameter and 4 mm depth, the second one for Filtek Z250 Universal Restorative
... Show MoreThe current research aims to identify the level of effective leadership practices dimensions (clear vision and specific goals, good planning and effective influence, and monitoring well as evaluation) among the senior leaders in the Office of the Iraqi Interior Ministry., The researchers adopted the descriptive analytical approach to collect data through the questionnaire as a main tool, developed by relying on international standards after making adjustments to its items consisting of (25) items that included the research variable, the questionnaire was distributed to all the research community (comprehensive inventory) by 120 forms from emplo
... Show More