The use of worn-out agricultural nozzles in pesticide application has a negative effect on the efficiency and cost of the application process. It also has an effect on environmental pollution due to an excessive amount of pesticide being applied when spraying with worn-out nozzles. In this paper, the resistance to wear of three different internal design hydraulic nozzles was ascertained. Changes in the flow rate and spray distribution as a result of this wear were also investigated. The wear test was done inside a closed system, and it was accelerated using an abrasive material to generate 100 h of wear. The tested nozzles were the Turbo TeeJet (TT)-twin chambered, Turbo Twinjet (TTj60)-dual outlet, and Drift Guard (DG)-pre-orifice. Wear rate, flow rate, and the virtual coefficient of variation (CVv) were measured at different wear intervals. The results showed that the TTj60 type was the most resistant to wear, followed by the TT type and DG. The latter two types showed an increase in the flow rate only in the first 45 h of wear. Virtual coefficient of variation (CVv) values were less than 10% after finishing the test (after 100 h of wear) for the three types of nozzles, which are acceptable values according to International Organization for Standardization (ISO) 16122-2, 2015.
The current study performs an explicit nonlinear finite element simulation to predict temperature distribution and consequent stresses during the friction stir welding (FSW) of AA 7075-T651 alloy. The ABAQUS® finite element software was used to model and analyze the process steps that involve plunging, dwelling, and traverse stages. Techniques such as Arbitrary Lagrangian–Eulerian (ALE) formulation, adaptive meshing, and computational feature of mass scaling were utilized to simulate sequence events during the friction stir welding process. The contact between the welding tool and workpiece was modelled through applying Coulomb’s friction model with a nonlinear friction coefficient value. Also, the model considered the effect of nonlin
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The internal control is the tool through which it is possible to verify and ensure the implementation of tasks in accordance with the established plans and programs and to evaluate the level of performance that is implemented within the different companies.
A guarantee from the supplier with the absence of a specialized technical committee that follows up the stages of implementing the contract and disbursing all amounts of financial dues to the supplier before completing the implementation of the contract and overlooking the non-implementation of some clauses of the contract by the committee in charge of
... Show MoreThis study was aimed to develop an optimized Dy determination method using differential pulse voltammetry (DPV). The Plackett-Burman (PB) experimental design was used to select significant factors that affect the electrical current response, which were further optimized using the response surface method-central composite design (RSM-CCD). The type of electrolyte solution and amplitude modulation were found as two most significant factors, among the nine factors tested, which enhance the current response based on PB design. Further optimization using RSM-CCD shows that the optimum values for the tw
... Show MoreThe results of theoretical and experimental investigations carried out to study the effect of load and relative sliding speed on the abrasive wear behavior in drilling bit teeth surfaces of an insert tungsten carbide bit have been presented. Experimentally, an apparatus for abrasive wear tests conducted on the modified ASTM-G65 was modified and fabricated to facilitate loading and measurement of wear rate for the sand/ steel wheel abrasion test, which involves two cases of contact; first is at dry sand and second is under wet condition. These tests have been carried under varied operating parameters of normal load and sliding speed. A theoretical model based upon the Archard equation has been developed for predicting wear simulation by u
... Show MoreIn this paper, the wear in layers of articular cartilage was calculated, parameters effective on elastic deformation were studied in normal and diseased knee joints, and relations between elastic deformation and squeeze film characteristics under lubrication condition were discussed with using a mathematical model. Conferring to the results obtained, elastic deformation effects on the performance of synovial human knee joint were analyzed from medical and dynamics perspectives. Relationships between elastic deformation and wear of layers were also discussed.
Background: Mouthwashes used widely as ancillary to mechanical oral hygiene methods. Little information provided about the effect of mouthwashes on ions released from orthodontic brackets. Therefore, the present study has been established to evaluate the effect of different mouthwashes on the corrosion resistance and the biocompatibility of two brands of brackets. Materials and Methods: Eighty premolar stainless steel brackets were used (40 brackets from each brand). They were subdivided into four subgroups (n=10) according to immersion media (deionized distilled water, Corsodyl, Listerine and Silca herb mouthwashes). Each bracket was stored in a closely packed glass tube filled with 15ml of the immersion media and incubated for 45 days at
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Background : The aim of this work is to assess the role of breast sonography and ductography in the evaluation of different causes of nipple discharge.
Methods : The study will be carried out on twenty-five female patients referred to the Radiodiagnosis department at Alexandria Main University Hospital presenting with nipple discharge.
They were divided into two groups:
Group I include 10 patients (40%) with surgically significant nipple discharge who were the patients with unilateral, uniorificial surgically significant colour type nipple discharge .They were investigated by mammography, sonography, and ductography.
Group II include 15 patients
... Show MoreIn this work, the annual behavior and cross-correlation between three different solar-ionospheric indices were evaluated: Smoothed Sunspot Number (SSN), Ionospheric T-Index (T-index), and Solar Flux (F10.7 cm) index during solar cycles 23 and 24. The annual behavior for the three tested indices of the maximum and minimum years of the two solar cycles was studied. The correlative conducts between the studied indices were evaluated for the studied periods (1996-2008) and (2008-2019) of the 23rd and 24th solar cycles. The annual correlation between the studied indices was represented by the linear regression equation. The suggested mutual correlation equation gave a good agreement with the observed annual average values of the test
... Show MoreThe woman's choice of clothing is no longer supported on the basis of the available forms of design in general. It is the interaction of design relationships with the receiver structure that reflects the character of integrated women with an emphasis on attractions pulling attention, all of these interventions reach us to the need to emphasize through this search Picking the perfect symbols of heritage in every sense of the popular beliefs of the employed in the designs of apparel fabrics women's home included a search of four chapters deal with the first problem of the research which you can employ the traditional symbols and popular beliefs in the designs of household apparel fabrics in order to raise the aesthetic value and utility of
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