Esterification considers the most important reaction in biodiesel production. In this study, oleic acid was used as a suggested feedstock in order to study and simulate production of biodiesel. The batch esterification reaction of oleic acid was carried out at various operating conditions; temperature from 40 to 70 °C, ethanol to oleic acid molar ratio from 3/1 and 6/1 and a reaction time up to 180 min.
The catalyst used was prepared NaY zeolite, which is added to the reaction mixture as 2, 5 and 10 wt.% of oleic acid.
The results show that the optimum conditions, gives 0.81 conversion of oleic acid, were 6/1 molar ratio of ethanol/oleic acid, 5 wt.% NaY relative to initial oleic acid, 70°C and 60 minutes. The activation energy of the suggested model was 42692 J/mole for forward reaction and 17218 J/mole for backward reaction.
Soft robotics offers a flexible alternative to rigid systems, enabling safe and adaptive interaction in biomedical, wearable, and unstructured environments. Among available actuation methods, soft electromagnetic actuators are notable for their fast response, low operating voltage, and ease of integration. However, some designs require pre-stretching mechanism, which produces an external force to maintain the separation between the coil and permanent magnets. Additionally, there is a mechanical complexity and difficulty in calibrating the spring parameters precisely. Furthermore, the pre-stretching mechanism increases the electromagnetic force required to counteract the opposing spring force, leading to a significant increase in power consu
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Orthodontic education, besides some other factors, influences the confidence level of recently graduated dentists to diagnose subjects seeking orthodontic treatment and provide treatment plans. This study aims to explore the factors that influence the confidence level of undergraduate dental students to diagnose subjects seeking orthodontic treatment and provide treatment plans after graduation.
A qualitative study was undertaken using focus groups a
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The aim of this study is to find a relationship between oxidative stress and adiponectin in Iraqi patients with acromegaly. The present study included 30 patients with acromegaly disease attending at Al-Yarmuk teaching hospital , and 30 healthy individuals as a control group.The two groups with ages ranging (30-55) years. The results revealed a highly significant elevation in all parameters (GH,IGF-1 , adiponectin , malondialdehyde , and peroxynitrite ) levels in sera of patients when compared with healthy control .It can be concluded that oxidative stress (malondialdehyde and peroxynitrite ) may be valuable in detecting of endocrine diseases like acromegaly .
Climate change is a global environmental issue and a common concern for humanity, and it is an inevitable result of civilization development, especially after the industrial revolution All areas of life At the level of the Iraqi situation , Iraq faces several challenges posed by Climate change , Such as high temperature, lack of rain, water scarcity , land salinity , and the increase in the proportion of sand and dust storms and the resulting disasters, which impedes development and hinders efforts to reduce poverty , enhance livelihoods , and reduce conflict to obtain natural resources.
... Show MoreIraqi oil crudes have some of the physical and chemical characteristics that distinguish it from other types of oil crudes in the world. Some of these features such us molecular composition, rheological, viscosity and emulsions are studied carefully by researchers. In this work, a comparative study of the linear and the non-linear optical properties for typical heavy and light crude oils of Iraqi origin was studied utilizing Z-scan technique. The He -Ne laser of wavelength 632.8 nm had been used for this purpose. These samples were collected from Basra and Kut oil fields. The values of the non-linear refractive index (n2), non-linear absorption coefficient (β), and third-order electrical susceptibility (χ3) were e
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Heat exchanger is an important device in the industry for cooling or heating process. To increase the efficiency of heat exchanger, nanofluids are used to enhance the convective heat . transfer relative to the base fluid. - Al2O3/water nanofluid is used as cold stream in the shell and double concentric tube heat exchanger counter current to the hot stream basis oil. These nanoparticles were of particle size of 40 nm and it was mixed with a base fluid (water) at volume
concentrations of 0.002% and 0.004%. The results showed that each of Nusselt number and overall heat transfer coefficient increased as nanofluid concentrations increased. The pressure drop of nanofluid increased slightly than the base fluid because
The work presented in this research deals with the synthesis and physico-chemical characterization of Schiff base ligand (HL) created from vanillin with p-aminoazobenzene containing (N, O) as donor atoms. The synthesis ligand (HL) was characterized by the CHN, (FT-IR), (UV-Vis), (1H,13C-NMR) and mass spectroscopy, in addition the melting point were used to charac-terize the Schiff base. A series of mixed metal ligands complexes were formed by using Schiff base ligand (HL) as primary ligand and Paracetamol (PAR) as a secondary ligand with five divalent metal ions; Ni, Cu, Zn, Cd(II) and Hg. The formed complexes were characterized by using some analytical and standard spectroscopic methods; molar conductivity, magnetic susceptibil-ity, FT-IR,
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Hydrated lime has been recognized as an effective additive used to improve asphalt concrete properties in pavement applications. However, further work is still needed to quantify the effect of hydrated lime on asphaltic concrete performance under varied weather, temperature, and environmental conditions and in the application of different pavement courses. A research project was conducted using hydrated lime to modify the asphalt concretes used for the applications of wearing (surface), leveling (binder), and base courses. A previous publication reported the experimental study on the resistance to Marshall stability and the volumetric properties, the resilient modulus, and permanent deformation at three different weather temperatures. This
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