It is often noted that disordered materials have different chemical properties to their more “ordered” cousins. Quantifying these effects in terms of thermodynamics is challenging in part because disordered materials can be difficult to characterize and are frequently relatively unstable. During the course of our experiments to understand the effects of disorder in catalysts for water oxidation we observed that many disordered manganese and cobalt oxide water oxidation catalysts directly oxidized peroxide in contrast to their more ordered analogues which catalyzed its disproportionation, that is, MnO2+2H+ +H2O2! Mn2+ +2H2O+O2(oxidation) versus H2O2!H2O+1=2 O2(disproportionation). By measuring the efficiency for one reaction over the other as a function of pH, we were able to quantify the relative stability of materials in two series of metal oxides and thereby quantify their relative thermodynamic stability, “by proxy”. We found that for the series of catalysts investigated the disorder made the materials stronger chemical oxidants and worse catalysts for the disproportionation of peroxide
Electro coagulation treatment was used for zinc removal from electroplating wastewater of the State Company for Electrical Industries . This wastewater, here consists zinc ions with maximum concentration in solution of 90 ppm .
The parameters that influenced the wastewater treatment are: current density in the range 1-1.4 mA/cm2, pH in the range 5-10, temperature in the range 25-45°C and time in the range 10-180 minute.
The research is a laboratory experimental type using batch system for electrical process with direct current. The cell comprised of aluminum electrode as anode and stainless steel electrode as cathode. Thirty experiments and one hundred fifty sample lab tests were carried out in this research
... Show MoreMany undergraduate learners at English departments who study English as a foreign language are unable to speak and use language correctly in their post -graduate careers. This problem can be attributed to certain difficulties, which they faced throughout their education years that hinder their endeavors to learn. Therefore, this study aims to discover the main difficulties faced by EFL students in language learning and test the difficulty variable according to gender and college variables then find suitable solutions for enhancing learning. A questionnaire with 15 items and 5 scales were used to help in discovering the difficulties. The questionnaire was distributed to the selected sample of study which consists of 90 (male and female) stud
... Show MoreThe current study aims to assess the water quality of the Al-Diwaniyah River in the city of Al-Diwaniyah to drink in terms of chemical properties and heavy metals and their impact on the health of the local population. The results showed that most of the parameters in the river water are of low concentrations due to the limited human activities in polluting the river water. The study concluded that the water quality is suitable for drinking depending on major cations and anions in all seasons. The Heavy Metal Pollution Index (HPI) showed that the river water was clean and safe, except two slightly polluted samples. The study concluded that river water for drinking or various domestic uses does not pose any danger to human heal
... Show MoreBackground: The aim of this study was to evaluate the shear bond strength (SBS) and adhesive remnant index (ARI) of different orthodontic adhesive systems after exposure to aging media (water storage and acid challenge). Materials and methods: Eighty human upper premolar teeth were extracted for orthodontic purposes and randomly divided into two groups (40 teeth each): the first group in which the bonded teeth were stored in distilled water for 30 days at 37°C, and the second group in which the bonded teeth were subjected to acid challenge. Each group was further subdivided into four subgroups (10 teeth each) according to the type of adhesive system that would be bonded to metal brackets: either non-fluoride releasing adhesive (NFRA),
... Show MoreThe language that consists of only twenty-eight letters, but it is so broad that we are unable to understand it from all sides and this expansion is mainly caused by imagination, so Arab imagination, whose language goes in all directions And as it always responds to our ears, ancient critics divide imagination into holistic and partial But the language is not limited to these parts only. Do we wonder, where is the structural method of wishing, hope, questions and other methods of all this? In this paper, we try to show the importance of the method of writing in moving imagination in an interactive way, and what is related to human feelings in most, if not all, of its methods By studying the poetry of the believers in the Ahl al-Bayt, pea
... Show MoreDenture cleansing is an essential step that can stop cross‑contamination and adds to the health of the patient, denture durability, and the general quality of life. A disinfection technique must be practical and devoid of damaging effects on the material's properties used to construct the denture base. The main aim of this study is to evaluate the effect of three concentrations of electrolyzed water denture cleanser on heat cure acrylic and polyamide after immersion in electrolyzed water. The evaluation is based on their efficacy on surface hardness, wettability, and color stability compared with one submerged in distilled water as a control group. The method consists of eighty samples of heat-cured acrylic and polyamide material.
... Show MoreThe aim of this research is to determine the uranium concentration in soil and water samples taken from different locations from the middle and south of Iraq using fission fragments track registration. Twelve samples of soil and water were taken from middle and South of Iraq. The nuclear reaction used as a source of nuclear fission fragments is U-235 (n.f) obtained by bombardment U-235with thermal neutrons from (Am-Be) neutron source with flux (5X103 n.cm-2.s-1). The concentration values were calculated by a comparison with standard samples recommended by IAEA.The results of the measurements show that the uranium concentration in soil samples were in Thekar (16.38 ppm), AL-Basra (16.1ppm) and (0.78 ppm) in Baghdad, from the results
... Show MoreBackground: World Health Organization (WHO) and United Nation International Children Fund (UNICEF) developed a strategy known as Integrated Management of Childhood Illness (IMCI); which aims to reduce less than five years children morbidity and mortality in developing countries.
Objective: To assess the completion of the IMCI format status in primary health care centers, Baghdad.
Methods: A cross sectional study with analytic element was conducted during the period from 15th of January till 15th May 2016 in selected Primary health centers in Baghdad, Iraq. The sample consists of form of child files less than 2 months and form from 2
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