The main objective of present work is to describe the feasibility of friction stir welding (FSW) for
joining of low carbon steel with dimensions (3 mm X 80 mm X 150 mm). A matrix (3×3) of welding
parameters (welding speed and tool rotational speed) was used to see influence of each parameter on
properties of welded joint .Series of (FSW) experiments were conducted using CNC milling machine
utilizing the wide range of rotational speed and transverse speed of the machine. Effect of welding
parameters on mechanical properties of weld joints were investigated using different mechanical tests
including (tensile and microhardness tests ). Micro structural change during (FSW) process was
studied and different welding zones were investigated using optical microscope. The stir welding
experiments conducted that show the low carbon steel can be welded using (FSW) process with
maximum welding efficiency (100.02%) in terms of ultimate tensile strength using best result of
welding parameters (700 RPM, 25 mm/min, tool rotational speed and welding speed respectively and
0.2 mm plunging depth of welding tool) ,there is afirst time that we obtain the efficiency reach to
100.02 % to weld this type of low carbon steel by FSW. The corrosion resistance was measure which
is the new test on the welding by this way and we obtained different result from the result on
traditional welding processes and the result that obtained show the corrosion resistance for this
welding plate better than the base metal. Maximum temperature has been calculated numerically by
using the ANSYS program. The obtained peak temperature is 1102°C, A percentage minimum of the
melting point .
Concentrations of radon were measured in this study for twenty-four samples of soil distributed in six locations on the north part of Iraq. The radon concentrations in soil samples measured by using alpha-emitters registration that emits from Radon (222Rn) in (CR-39) track detector. The concentrations values were calculated by a comparison with standard samples. The results shows that the radon gas concentrations in Darbandikhan City varies from (16.60-34.04 Bq/m3), Halabja City (16.51-23.32 Bq/m3), Al Sulaimaniya City (17.61-32.25 Bq/m3), Koisnjaq City (22.04-35.65 Bq/m3), Shaqlaua City (21.10-29.10 Bq/m3) and Erbil City (22.30-34.63 Bq/m3). The average radon gas concentration in Al Sulaimaniya and Erbil governorate are (22.30 Bq/m3)
... Show MoreIn this paper the experimentally obtained conditions for the fusion splicing with photonic crystal fibers (PCF) having large mode areas were reported. The physical mechanism of the splice loss and the microhole collapse property of photonic crystal fiber (PCF) were studied. By controlling the arc-power and the arc-time of a conventional electric arc fusion splicer (FSM-60S), the minimum loss of splicing for fusion two conventional single mode fibers (SMF-28) was (0.00dB), which has similar mode field diameter. For splicing PCF (LMA-10) with a conventional single mode fiber (SMF-28), the loss was increased due to the mode field mismatch.
Densely deployment of sensors is generally employed in wireless sensor networks (WSNs) to ensure energy-efficient covering of a target area. Many sensors scheduling techniques have been recently proposed for designing such energy-efficient WSNs. Sensors scheduling has been modeled, in the literature, as a generalization of minimum set covering problem (MSCP) problem. MSCP is a well-known NP-hard optimization problem used to model a large range of problems arising from scheduling, manufacturing, service planning, information retrieval, etc. In this paper, the MSCP is modeled to design an energy-efficient wireless sensor networks (WSNs) that can reliably cover a target area. Unlike other attempts in the literature, which consider only a si
... Show MoreArcHydro is a model developed for building hydrologic information systems to synthesize geospatial and temporal water resources data that support hydrologic modeling and analysis. Raster-based digital elevation models (DEMs) play an important role in distributed hydrologic modeling supported by geographic information systems (GIS). Digital Elevation Model (DEM) data have been used to derive hydrological features, which serve as inputs to various models. Currently, elevation data are available from several major sources and at different spatial resolutions. Detailed delineation of drainage networks is the first step for many natural resource management studies. Compared with interpretation from aerial photographs or topographic maps, auto
... Show MoreChickenpox is a viral disease caused by a virus called varicella zoster (VZ). Chickenpox cases were counted in Al-Dora city (southern Baghdad). Data of disease was obtained from the records of Bilat Al-Shuhadaa health center at the period from January to July 2012. Diagnosis of cases was achieved by the physicians of the health center. Studied risk factors were including the gender, address, school and age. Total of cases recorded was 73cases (66.9 per 100,000) populations for seven months. Males reported cases were 48 (65.7%) while female’s cases were 25(34.3%). The highest reported cases were signed in Al-Mhdia-1 sector (24.6%).Also highest reported cases were signed in Al-Mhdia primary school (17.8%). Most VZ cases were reported in
... Show MoreIn the framework of correlation method so-called coherent density fluctuation model (CDFM) the nucleon momentum distributions (NMD) of the ground state for some even mass nuclei of fp-shell like 50Cr, 52Cr and 54Cr isotopes are examined. Nucleon momentum distributions are expressed in terms of the fluctuation function (|f(x)|2) which is evaluated by means of the nucleon density distributions (NDD) of the nuclei and determined from theory and experiment. The main characteristic feature of the NMD obtained by CDFM is the existence of high-momentum components, for momenta k ≥ 2 fm−1. For completeness, also elastic electron scattering form factors, F(q) are evaluated within the same framework.
—This paper studies the control motion of a single link flexible joint robot by using a hierarchical non-singular terminal sliding mode controller (HNTSMC). In comparison to the conventional sliding mode controller (CSMC), the proposed algorithm (NTSMC) not only can conserve characteristics of the convention CSMC, such as easy implementation, guaranteed stability and good robustness against system uncertainties and external disturbances, but also can ensure a faster convergence rate of the systems states to zero in a finite time and singularity free. The flexible joint robot (FJR) is a two degree of freedom (2DOF) nonlinear and underactuated system. The system here is modeled as a fourth order system by using Lagrangian method. Based on t
... Show MorePure and iron-doped cadmium oxide ((CdO)1-xFex) thin films at different ratios were prepared using pulsed laser deposition technique. The X-ray diffraction showed a polycrystalline structure for all samples associated with cubic CdO structure. Another phase appeared at the highest ratio corresponding to the cubic Fe phase. Crystallinity was enhanced and crystalline size increased with increasing Fe ratio. AFM measurements showed that increase of Fe ratio led to an increase in the average particle diameter. In addition, the distribution of particle size became wide and of irregular behaviour, as well as increasing of the average roughness and the root-mean-square roughness. Increasing the Fe ratio caused
... Show MoreIn this paper, thermal properties were performed by using semi-empirical theoretical calculations to study the molecular structure of a nonlinear molecular system, the (S2F2) molecule in the infrared region, by using semi-empirical quantum programs in the (MNDO / PM3) method. This study is under the condition of obtaining the stable structure of the molecule in which the molecule obtains the minimum value of the total energy. The thermodynamic properties were also calculated, including the heat of formation, whose value was (-61.002kcal / mol), the entropy and its value (78.2916 cal / mol.k), as well as the heat capacity (15.9454 cal / mol.k) and the enthalpy (3763.434 cal /mol), Gibbs F
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