In this paper, an analytical solution describing the deflection of a cracked beam repaired with piezoelectric patch is introduced. The solution is derived using perturbation method. A novel analytical model to calculate the proper dimensions of piezoelectric patches used to repair cracked beams is also introduced. This model shows that the thickness of the piezoelectric patch depends mainly on the thickness of the cracked beam, the electro-mechanical properties of the patch material, the applied load and the crack location. Furthermore, the model shows that the length of the piezoelectric patches depends on the thickness of the patch as well as it depends on the length of the cracked beam and the crack depth. The additional flexibility of the beam caused by crack is modeled depending on a dimensionless parameter identified from finite elements method. Different piezoelectric patches were designed and investigated using analytical and finite elements models. The results show that increasing the patch thickness enhances the beam resistance to crack and load effects, while increasing the length of the piezoelectric patch reduces the magnitude of the voltage required to repair the cracked beam.
Background: MicroRNAs (miRNAs) are small noncoding RNAs that postâ€transcriptionally regulate gene expression by targeting specific mRNAs. The main objective of this study was measure the level of salivary (hsa-miR-200a, hsa-miR-125a and hsa- miR-93) in both oral squamous cell carcinoma and healthy controls to asses the association of them with age, gender and tumor grade materials and methods The level of three salivary microRNAs namely hsa-miR-200a, hsa-miR-125a and hsa- miR-93 were measured in saliva of patients with oral squamous cell carcinoma and healthy controls by using reveres transcription, preamplification and quantitative PCR also the general information from each patient including the age, sex and tumor grade were record
... Show MorePurpose/ to build clear perceptions about the level of the effects of organizational failures on the competitiveness of dairy factories and the role of dynamic knowledge capabilities in minimizing these impacts
Mythology/ Design approach Use deduction approach, the research was conducted in four dairy factories in Baghdad (Abu Ghraib, Agriculture, Halal and Ayon Al-Rafidain). It was applied to a sample of (155) individuals representing a sample of the research community from factory owners, managers, Engineers, technicians and experienced workers in the dairy industry. The questionnaire was used as a main tool for collecting data, information and statistical tools in the extraction, testing and analysis o
... Show MoreGeophysics is one of the branches of Earth sciences and deals with studying the Earth's interior by studying the variation of physical properties within rock layers. Applied geophysics depends on procedures that involve the measurements of potential fields, such as the gravitational method. One of the significant oil fields in southern Iraq is represented by the Nahr Omar structure. A power spectrum analysis (SPA) technique was used to collect gravity data within the chosen oil field area in order to confirm the salt dome in the subsurface layers. The analysis of SPA resulted from six surfaces representing the gravity variation values of the depths (m)14300, 3780, 3290, 2170, 810, and 93.5. Gravity surfaces have been converted to de
... Show MoreThe current research aimed to identify the tasks performed by the internal auditors when developing a business continuity plan to face the COVID-19 crisis. It also aims to identify the recovery and resuming plan to the business environment. The research followed the descriptive survey to find out the views of 34 internal auditors at various functional levels in the Kingdom of Saudi Arabia. Spreadsheets (Excel) were used to analyze the data collected by a questionnaire which composed of 43 statements, covering the tasks that the internal auditors can perform to face the COVID-19 crisis. Results revealed that the tasks performed by the internal auditors when developing a business continuity plan to face the COVID-19 crisis is to en
... Show MoreThe research involves using phenol – formaldehyde (Novolak) resin as matrix for making composite material, while glass fiber type (E) was used as reinforcing materials. The specimen of the composite material is reinforced with (60%) ratio of glass fiber.
The impregnation method is used in test sample preparation, using molding by pressure presses.
All samples were exposure to (Co60) gamma rays of an average energy (2.5)Mev. The total doses were (208, 312 and 728) KGy.
The mechanical tests (bending, bending strength, shear force, impact strength and surface indentation) were performed on un irradiated and irrad
... Show MoreThis research aims to find out the relationship of risk behavior & job satisfaction for workers in the emergency program in the international relief agency (UNRWA) in the Gaza Strip and the level of each of them, and to achieve that we have been conducting research on the strength of "210" sample employees of the emergency program staff in the international relief agency in Gaza governorates, and try to answer the research questions the researcher through the use of measurements of risk behavior and job satisfaction are two of the researcher, The researcher has used several statistical methods to identify the validity and reliability of scales and access to research and interpretations of the results, and these methods: the m
... Show MoreThe aim of the study was to know the factors analysis of scale Bar-On & Parker, post analysis is found fourteen factors for the first degree of the scale. Also we extracted five factors from the second degree.
The scale consists of (60) items , applied on sample of (200) students (Male &Female ) age (15-18) years randomly chosen from preparatory schools . The scale unveiled satis factors validity and reliability. An others aims is to low the emotional Intelligence level and know the difference of statistical in sex , age variable and the specialization variable .The result was no difference of statistical in sex and specialization variable , but the difference appear
... Show MoreWe use of multi-choice Goal Programming (MCGP), which is a developed model of Goal Programming where it is used in circumstances of the multiplicity and difference of goals when choosing between decision alternatives in cases of allocating resources, as it is a model that seeks to find the closest and best solutions to the specific values of the goals within the aspiration levels, as the first goal in the multi-choice goal programming model that is used to reduce the total cost of storage and shortage, while the other goal was to reduce the difference between the real demand that the hospitals need from the blood transfusion center and the units that already achieved. The case Iraqi Center
... Show MoreObjective: Evaluation the national standards for exposure to chemical materials and dusts in The State
Company for Drugs Industry in Samarra.
Methodology: A descriptive evaluation design is employed through the present study from 25th May 2011
to 30th November 2011 in order to evaluate the national standards for exposure chemical materials and dusts
in The State Company for Drugs Industry in Samarra. A purposive (non-probability) sample is selected for the
study which includes (110) workers from the State Company for Drugs Industry in Samarra. Data were
gathered through the workers` interviewed according to the nature of work that they perform. The evaluation
questionnaire comprised of three parts which include the w