The coefficient of friction was experimentally calculated for aluminum-silicon alloys by
connecting a strain gauge to the arm of pin-on-disc wear machine in order to take microstrain
readings from the strain-meter. As-cast and modified aluminum-silicon alloys were thermally
homogenized for long periods of time (1-40hr) in order to study the effect of homogenization on
friction. Scanning electron microscopy was successfully used to build up the mechanism of surface
damage during sliding. The results showed that the coefficient of friction was increased with
increasing bearing pressure for as-cast, modified and homogenized aluminum-silicon alloys.
Thermal homogenization led clearly to remarkable changes in the friction
The aim of this work is to study the effect of diesel fuel percentage on the combustion processes in compression ignition engine using dual – fuel (diesel and LPG).
The brake thermal efficiency increased with the increase of diesel fuel rate at low loads, and decreased when load increased. To get sufficient operation in engine fueled with dual fuel, it required sufficient flow rate of diesel fuel, if the engine fueled with insufficient diesel fuel erratic operation with miss fire cycles presented.
Dual-fuel operation at part load showed higher specific fuel consumption than straight diesl operation. At full loads, brake specific fuel consumption of duel fuel engine approaches that for diesel fuel values.
A study of the hadiths of supplication orchestration
The purpose of this research is to investigate the effects of rotation on heat transfer using
inclination magnetohydrodynamics for a couple-stress fluid in a non-uniform canal. When the
Reynolds number is low and the wavelength is long, math formulas are used to describe the stream
function, as well as the gradient of pressure, temperature, pressure rise and axial velocity per
wavelength, which have been calculated analytically. The many parameters in the current model
are assigned a definite set of values. It has been noticed that both the pressure rise and the pressure
gradient decrease with the rise of the rotation and couple stress, while they increase with an
increase in viscosity and Hartmann nu
Anabolic androgenic steroids are being more popular between bodybuilders and people who are using gym to enhance their physiques. However, according to the increase of the laws prohibiting sales of these substances without physician prescription, the route of getting and administration practices have become more and more dangerous. Anabolic androgenic steroids include many synthetic derivatives of testosterone its play a significant role in medical treatment. These groups of medications are extensively abused at young ages to rising lean body mass and advance the athletic quality of performance. It has been described that anabolic steroids use can cause many long and short-term side effects, this study intended to assess the level of kno
... Show MorePancreatic islets of Turkey were different from those of mammals. It is divided into alpha, beta and mixed types according to the ground of cellular composition
التدخين من العادات السلبية والسيئة التي يعاني منها المجتمع وبالاخص شريحة الشباب ومنهم طلبة الكليات . حيث وجد اعداد لايستهان بها من المدمنين على التدخين في كلية التربية الرياضية التي هي احدى صروح الصحة مما يدعو للقلق حيث يؤثر على انجازاتهم الرياضية والصحية .ركز الباحث على السلوكيات الاربع التي دعت الطلاب الى الانغمار في الادمان وهدا خطر على الصحة العامة والوقوع في شرك الامراض الخطرة .لقد استنتج ال
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Resistance spot welding (RSW) aluminum alloys has a major problem of inconsistent quality from weld to weld, because of the problems of the non-uniform oxide layer. The high resistivity of the oxide causes strong heat released which influence significantly on the electrode lifetime and the weld quality. Much effort has been devoted experimentally to the study of the sheet surface characteristics for as-received sheet and surface pretreatment sheet by pickling in NaOH and glassblasted with three thicknesses (0.6, 1.0, and 1.5 mm) of AA1050. Three different welding process parameters energy setup as a low, medium, and high were carried. Tensile-shear strength tests were performed to indicate the weld quality. Moreover, microhardness tests,
... Show MoreThe media plays an important role in a number of functions performed by them. Press is one of those media which had and still have a clear role in addressing the various issues, topics, and events. Journalism is no longer as expressed by owners of the liberal theory – it seeks to raise the instincts – but it began to excite the minds of readers to meet their needs. At the same time, it does not neglect the search for the truth and work to deliver it to readers. Some have identified a set of tasks carried out by the press including the interest in public affairs, the needs of the community, work to provide happiness, what is beneficial and useful and combat the negative phenomenon and to address the deviations facing society. The comi
... Show MoreIn recent years, robotic systems have been widely used in different applications, and this has motivated researchers to develop different control methods. A model-free, intelligent, robust control method for a nonlinear robotic manipulator system is proposed in this work. This paper presents a novel solution for the major drawbacks of the sliding mode control scheme, which are chattering. Prior knowledge is needed about the dynamic model of the controlled system and the upper bound of uncertainty. In this paper, a fuzzy-like PD controller with SMC (FLPDSM) is proposed. The fuzzy-like PD controller was designed according to fuzzy rules and membership functions based on the nominal model of the robot manipulator. A robust control term wa
... Show MoreIn order to make a balance between the increasing of potable water demand and the available
quantity, a pipe network should be managed in an optimal hydraulic operation state. The optimal
operation of a water supply network leads to minimize the effect of the variance in pressure
between the available and minimum required pressure head. It simulates the hydraulic model and
puts the optimized project with the constraints (minimum design head=20 m, and the available
commercial pipe diameter, 1600³D³250 mm). The objective function is to minimize the cost for
the suggested hydraulic solution to a minimum value. Pressure uniformity coefficient (UC),
Standard deviation () and coefficient of variance (Cv) are used to sho
Supra nanoparticles (submicron) of Chicken bones fibers were used (before and after treated with citric acid solution) as additives to dental composite with the weight ratios (1%, 2% and 4%). The main mechanical tests represented by hardness, wear resistance and compression strength was carried out on the improvement dental composites.
The addition of treated supra nanoparticles Chicken thigh bones with particles size (300 nm) by weight ratio (1%) to ordinary dental composite resin , significantly improves all of its mechanical properties, in addition to the increase the value of the its glass transition temperature from 43oC to 45.4 oC. The techniques X-ray diffraction (XRD), Energy Dispersive Spectr
... Show Moreهدفت الدراسة تقويم المعرفة لمادة تاريخ وفلسفة التربية الرياضية لدى طلبة كلية التربية الرياضية كما هدفت الى معرفة المجال الذي ترتفع فيه نسبة المعرفة وافترضت الباحثة ان هناك مستوى عالي من المعرفة الفلسفية والتاريخية كما ان مستوى المعرفة لدى إفراد العينة يختلف باختلاف المجالات .استخدمت الباحثة الاستبيان كوسيلة لجمع البيانات وشملت عينة البحث طلبة كلية التربية الرياضية المرحلة الأولى والبالغ عددهم(225).واستخد
... Show MoreEffect of drought stress induced by mannitol on secondary products in callus of Golden Sunrise cherry tomatoes were studied in vitro. Seeds were irradiated with gamma at the doses (0, 20, or 40 Gy), and germinated on Murashige and Skoog, (MS) basal medium. Callus were initiated from cotyledon leaf explants using a combination of (2.0 kin + 2.0 IAA mg. l-1) then transferred into MS medium supplemented with mannitol at concentrations of (0, 40, and 60 g.l-1). Vitamin C(vit C), enzyme activity, Ascorbate peroxidase (Apx), and Amylase enzymes, Proline amino acid and β- carotene were quantified by high-performance Performance Liquid Chromatography (HPLC). Results revealed that, highest contents of (Apx) 128.16 µg. m
... Show MoreThe current investigation concluded an anatomical study of the cultivated species Pelargonium graveolens L. 'Hér belong to the Geraniaceae family and which cultivated as an ornamental plant, fresh specimen were collected from different region in Baghdad ,the study vegetative parts (leaf, stem and petiole) in details ,the upper and lower epidermis of leaf and epidermis of stem also studied, ordinary epidermal cells and stomatal complexes studied in term of shapes and dimensions ,the result showed that stomatal in leaf and stem is anomocytic type, the cross sections of the vegetative parts prepared by microtome and free hand sectioning. The tissues of these parts include the number an
... Show MoreTo fabricate an inexpensive surface coating with excellent mechanical properties with good water resistance and thermal diffusion, white eggshell fibers with particle size (~1micrometer) has been added by different weight percentages (1,2,3,4,5,6,7 and 8 %) to Unsaturated Polyester.
The weight ratio (4%) of eggshell powder is a good ratio to be added to polyester to improve its mechanical properties, such as hardness, impact strength, and wear resistance. The hardness was improved by (3.75%); impact strength has the same value as polyester, flexural strength by (8.43%) and high improvement in wear resistance (74.4%), as well as to get further improvements in mechanical properties of polyester, the eggshell powder was added
... Show MoreA non-polynomial spline (NPS) is an approximation method that relies on the triangular and polynomial parts, so the method has infinite derivatives of the triangular part of the NPS to compensate for the loss of smoothness inherited by the polynomial. In this paper, we propose polynomial-free linear and quadratic spline types to solve fuzzy Volterra integral equations (FVIE) of the 2nd kind with the weakly singular kernel (FVIEWSK) and Abel's type kernel. The linear type algorithm gives four parameters to form a linear spline. In comparison, the quadratic type algorithm gives five parameters to create a quadratic spline, which is more of a credit for the exact solution. These algorithms process kernel singularities with a simple techniqu
... Show MoreGraphene-carbon nitride can be synthesized from thiourea in a single step at a temperature of four hours at a rate of 2.3 ℃/min. Graphene-carbon nitride was characterized by Fourier-transform infrared spectroscopy (FTIR), energy dispersive X-ray analysis (EDX), scanning electron microscopy, and spectrophotometry (UV-VIS). Graphene-carbon nitride was found to consist of triazine and heptazine structures, carbon, and nitrogen. The weight percentage of carbon and the atomic percentage of carbon are 40.08%, and the weight percentage of nitrogen and the atomic percentage of nitrogen are 40.08%. Therefore, the ratio and the dimensions of the graphene-carbon nitride were characterized by scanning electron microscopy, and it was found that the
... Show MoreChemical compounds, characteristics, and molecular structures are inevitably connected. Topological indices are numerical values connected with chemical molecular graphs that contribute to understanding a chemical compounds physical qualities, chemical reactivity, and biological activity. In this study, we have obtained some topological properties of the first dominating David derived (DDD) networks and computed several K-Banhatti polynomials of the first type of DDD.
This paper is concerned with the quaternary nonlinear hyperbolic boundary value problem (QNLHBVP) studding constraints quaternary optimal classical continuous control vector (CQOCCCV), the cost function (CF), and the equality and inequality quaternary state and control constraints vector (EIQSCCV). The existence of a CQOCCCV dominating by the QNLHBVP is stated and demonstrated using the Aubin compactness theorem (ACTH) under appropriate hypotheses (HYPs). Furthermore, mathematical formulation of the quaternary adjoint equations (QAEs) related to the quaternary state equations (QSE) are discovere so as its weak form (WF) . The directional derivative (DD) of the Hamiltonian (Ham) is calculated. The necessary and sufficient conditions for
... Show MoreIn this study, gamma ray transmission method have been used to determine the total porosity in four samples: pure Alumina ( Al2O3 ), Al2O3 + (0.2wt%)MgO , Al2O3 + (0.6wt% )Y2O3 and Al2O3+ (8wt% ) ZrO2 .
The experimental setup for the gamma ray transmission consist of 137Cs gamma source ( 662 KeV ), a NaI (Tl) scintillation detector measured the attenuation of strongly collimated gamma beam through alumina samples.
The porosity obtained by the gamma ray transmission method were compare
... Show MoreRock engineers widely use the uniaxial compressive strength (UCS) of rocks in designing
surface and underground structures. The procedure for measuring this rock strength has been
standardized by both the International Society for Rock Mechanics (ISRM) and American Society
for Testing and Materials (ASTM), Akram and Bakar(2007).
In this paper, an experimental study was performed to correlate of Point Load Index ( Is(50))
and Pulse Wave Velocity (Vp) to the Unconfined Compressive Strength (UCS) of Rocks. The effect
of several parameters was studied. Point load test, Unconfined Compressive Strength (UCS) and
Pulse Wave Velocity (Vp) were used for testing several rock samples with different diameters.
The predicted e
Generally fossil based fuels are used in internal combustion engines as an energy source.
Excessive use of fossil based fuels diminishes present reserves and increases the air pollution in
urban areas. This enhances the importance of the effective use of present reserves and/or to develop
new alternative fuels, which are environment friendly. Use of alternative fuel is a way of emission
control. The term “Alternative Gaseous Fuels” relates to a wide range of fuels that are in the
gaseous state at ambient conditions, whether when used on their own or as components of mixtures
with other fuels.
In this study, a single cylinder diesel engine was modified to use LPG in dual fuel mode to study
the performance, emis
Abstract
The phonetic replacement is the process of putting a sound or a linguistic
syllable instead of another in one word that results in changing its meaning . It is one
way of vocabulary varionsness and discrimination because replacement among the
sounds of one expression and changing its image lead to change its meaning , and
accordingly , each replaced sound has its own linguistic value that distinguishes it . In
other words , the phonetic replacement is based on system of phonemic change
which is a general phenomenon in all languages . The linguistic system doesn’t stand
straight for word unless it is based on different standards that work on variousness ,
assortment and relating the phonetic change wi
The objective of drilling parameters optimization in Majnoon oilfield is to arrive for a methodology that considers the past drilling data for five directional wells at 35 degree of inclination as a baseline for new wells to be drilled. Also, to predicts drilling performance by selecting the applied drilling parameters generated the highest rate of penetration (ROP) at each section. The focal point of the optimization process is to reduce drilling time and associated cost per each well. The results of this study show that the maximum ROP could not be achieved without sufficient flow rate to cool and clean the bit in clay intervals (36" and 24") hole sections. Although the influence of combination of Weight on Bit (WOB), Round per mi
... Show MoreSome nonlinear differential equations with fractional order are evaluated using a novel approach, the Sumudu and Adomian Decomposition Technique (STADM). To get the results of the given model, the Sumudu transformation and iterative technique are employed. The suggested method has an advantage over alternative strategies in that it does not require additional resources or calculations. This approach works well, is easy to use, and yields good results. Besides, the solution graphs are plotted using MATLAB software. Also, the true solution of the fractional Newell-Whitehead equation is shown together with the approximate solutions of STADM. The results showed our approach is a great, reliable, and easy method to deal with specific problems
... Show MoreIn this research, we study the changing structural properties of ZnO with changing annealing temp., in the range (473-773)K prepared by chemical bath deposition method at temp. (353)K, where deposited on glasses substrates at thickness (500±25)nm, the investigation of (XRD) indicates that the (ZnO) films are polycrystalline type of Hexagonal.
The results of the measuring of each sample from grain size, microstrain, dislocation density, integral breadth, shape factor and texture coefficient, show that annealing process leads to increase the grain size (26.74-57.96)nm, and decrease microstrain (0.130-0.01478), dislocation density (1.398-0.297)*1015
... Show MoreIn this paper , we study some approximation properties of the strong difference and study the relation between the strong difference and the weighted modulus of continuity