The photo-electrochemical etching (PECE) method has been utilized to create pSi samples on n-type silicon wafers (Si). Using the etching time 12 and 22 min while maintaining the other parameters 10 mA/cm2 current density and HF acid at 75% concentration.. The capacitance and resistance variation were studied as the temperature increased and decreased for prepared samples at frequencies 10 and 20 kHz. Using scanning electron microscopy (SEM), the bore width, depth, and porosity % were validated. The formation of porous silicon was confirmed by x-ray diffraction (XRD) patterns, the crystal size was decreased, and photoluminescence (PL) spectra revealed that the emission peaks were centered at 2q of 28.5619° and 28.7644° for etching time 12 and 22 min, respectively. Studying the capacitance and resistivity during temperature increasing and decreasing for both itching times shows clearly that the prepared pSi as a thermal sensor is working better and in more selectivity for 20 min itching time
In this research the natural frequency of a cracked simple supported beam (the crack is in many places and in different depths) is investigated analytically, experimentally and numerically by ANSYS program, and the results are compared. The beam is made of iron with dimensions of L*W*H= (0.84*0.02* 0.02m), and density = 7680kg/m3, E=200Gpa. A comparison made between analytical results from ANSYS with experimental results, where the biggest error percentage is about (7.2 %) in crack position (42 cm) and (6 mm) depth. Between Rayleigh method with experimental results the biggest error percentage is about (6.4 %) for the same crack position and depth. From the error percentages it could be concluded that the Rayleigh method gives
... Show MoreThe study aims at measuring the dimensions of binding and non-binding social responsibility and its relation to the organizational performance in telecommunication companies in the Republic of Yemen using analytical descriptive approach and questionnaire as a main tool for data collection and comprehensive inventory method.
It has been found that there is a positive effect and significant moral relation between social responsibility with its binding and non-binding dimensions and the organizational performance of telecommunication companies in the Republic of Yemen at a level of significance below (0.05). It has also been found that the correlation between the non-binding social responsibilit
... Show MoreAccording to the circumstances experienced by our country which led to Occurrence of many crises that are the most important crisis is gaining fuel therefore , the theory of queue ( waiting line ) had been used to solve this crisis and as the relevance of this issue indirect and essential role in daily life .
This research aims to conduct a study of the distribution of gasoline station in (both sides AL – kharkh and AL Rusafa, for the purpose of reducing wasting time and services time through the criteria of the theory of queues and work to improve the efficiency of these stations by the other hand. we are working to reduce the cost of station and increase profits by reducing the active serv
... Show MoreThe performa of evaluation process is a process that should be carried out by all industrial management in order to stand on aspects of development or underdevelopment of the various departments and activities in its industrial project for the purpose of identifying obstacles and find out the causes and then avoid them quickly. And intended to rectify the performance evaluation of the activities of industrial project or economic union by measuring the results achieved within a specific operational process and compare it to what is already targeted, and often the time for comparison of one year.
The process of performance evaluation depends upon several criteria and indicators within the
... Show MoreThe scientific and practical importance of this study lies in analyzing the phenomena of commercial blocs as a means of managing the future struggle as Zbigniew Brzhenski in his book Our of Control which was translated into Arabic under the title of (chaos) in 1993. The most important phenomenon of the 21th century is the geopolitical phenomenon presented by the international blocs. That is, the new regime will be united in the form of economic blocs and political alliance. Consequently, the future struggle will be economic in nature under the chaos which the new order is living. Under the retreat of the economy that effected the industrial countries and the world countries which have become unable to treat the crisi
... Show MoreOne of the major problems in modern construction is the accumulation of construction and demolition waste; this study thus examines the consumption of waste brick in concrete based on the use of blended nano brick powder as replacement for cement and as a fine aggregate. Seven concrete mixes were developed according to ACI 211.1 using recycled waste brick. Nano powder brick at 0, 5, and 10% was used as a replacement by cement weight, with other mixes featuring 10, 20, and 30% partial replacement by volume of river sand with brick. The experimental results for replacement of cement with nano brick powder showed an enhancement in mechanical properties (compressive, flexural, and tensile strength) at 7,
Research seeks to test the impact of the dimensions of mindfulness on organizational Innovation, proposed in the light of the review literature on two variables of the research, which referred in General to the dynamic relationship between them, as result of weakness of mindfulness as one important factor driving the diversity of innovation and time, ways to sustain and preserve and then support innovations made by creators, weakness in the overall level of organizational Innovation, this represents the problem research, data collection over designing identification, distributed to sample Formed from (30) head Department at a number of colleges of the University of Baghdad, results confirms the validity of resea
... Show MoreThe inhibition of 3-Benzyl -2-mercaptoquinoizoline -4 (3H)-one (BMQ) on the corrosion of carbon steel in 0.5 M HCl studied by potentionstat polarization methods at 303–333 K. Results obtained show that BMQ act as inhibitor for carbon steel in HCl solution. The inhibition efficiency increase with increase in BMQ concentration. Activation parameters and Gibbs free energy for the adsorption process using Statistical Physics calculated and discussed. Quantum chemical calculations using DFT at the B3LYP/6-31G level of theory were used to calculate some electronic properties of the molecule to verify any correlation between the inhibitive effect and molecular structure of BMQ. The quantum calculations were proceeded to get data around correlati
... Show MoreAll businesses seek to improve their levels of profits through various means, most notably their marketing channels, which ensure the delivery of their products to their customers in a safe manner in a timely manner. It considers losses to a minimum and that insurance companies place great interest in marine insurance losses because they often constitute huge amounts compared to other losses, hence the problem of research, which is centred on the type and size of the impact owned by the channel The Iraqi insurance company was chosen to be applied according to the intentional sample method because this company is closely related to the subject matter. The research has reached a set of conclusions, most notably that the choice of i
... Show MoreInterested in many scholars and reseachers the subject of the media and means varied his roleinfluential in the definition of the public of issues and political, cultural, social and because of its spread wide and ability to address the people of all levels effect them in the formation consciousness of those issues and types of this awareness is an awareness of the tax, contribute to media formation consciousness tax through the definition of people what tax and importance of the role of its revenues to supplement the state budget by posting tax laws and regulations of applied and all what respect process account tax, to be in charge of the tax familiar enough about this, which avoid being cheated taxmisleading when rev
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