In this work, the copper metal was treated using Nd:YAG laser with energy 1Joul to enhance corrosion resistance and improve surface properties. The copper metal has many applications in industry as well as water, oil and gas pipes. The same conditions, (laser power density, scan speed, distance between paths, medium gas-air) were applied in the laser surface treatment, After laser treatment, the samples microstructures were investigated using optical microscope (OM) to examine micro structural changes due to laser irradiation. Specimen surfaces were investigated using atomic force microscopy (AFM), X-ray diffraction (XRD), macro hardness, and corrosion test before and after laser treatment to examine the surface properties changes as a result of laser irradiation, and X-ray fluorescence (XRF). Results showed that laser irradiation enhances the corrosion resistance of the metal copper. Corrosion rates as low as 0.550 mpy for laser treated samples were obtained in comparison to 0.699 mpy obtained for the untreated samples. The corrosion protection afforded by laser treatment is attributed mainly to the grain refinement of the top surface layer. This layer is found to consist of nano-scale grains. Higher hardness and lower average roughness due to laser surface treatment.
The present paper is an experimental study to improve the productivity of the conventional solar still. This done by modifying conventional still in a way that the distilled basin is larger than distillation basin, thus providing an increase in the condensation surface and speeding up the condensation process. Moreover, increase in the dimensions of the distilled base helps coupling reflective panels to the distilled base to reflect incident solar radiation to the distillation basin. For this purpose , two solar stills were made, one conventional designand another made according to the proposed design. The two solar stills were tested during the period from February to July 2009 under varying weather conditions of Basra, Iraq (latitude o
... Show MoreIn this work, we construct projectively distinct (k,3)-arcs in the projective plane PG(2,9) by applying a geometrical method. The cubic curves have been been constructed by using the general equation of the cubic. We found that there are complete (13,3)-arcs, complete (15,3)-arcs and we found that the only (16,3)-arcs lead to maximum completeness
those affected by technological development risks within the scope of medical works. The unprecedented technological development the world witnesses nowadays has been providing brilliant medical service to the human being including examination, diagnosis and the treatment or follow up. However, such works hide behind potential risks threatening people's lives and such risks my be discovered within the limits of now – how and technical knowledge prevailing the time of rendering the medical service. Also this the question is raised on how to keep up between the safety of the patients and such risks are being unknown by the provider and questioning them contradicts the justices. subsequently, can the patients (affected) acquire the compensat
... Show MoreGypseous soils are spread in several regions in the world including Iraq, where it covers more than 28.6% [1] of the surface region of the country. This soil, with high gypsum content causes different problems in construction and strategic projects. As a result of water flow through the soil mass, permeability and chemical arrangement of these soils vary over time due to the solubility and leaching of gypsum. In this study the soil of 36% gypsum content, is taken from one location about 100 km (62 mi) southwest of Baghdad, where the sample is taken from depth (0.5 - 1) m below the natural ground surface and mixed with (3%, 6%, 9%) of Copolymer and Styrene-butadiene Rubber to improve t
This paper present a simple and sensitive method for the determination of DL-Histidine using FIA-Chemiluminometric measurement resulted from oxidation of luminol molecule by hydrogen peroxide in alkaline medium in the presence of DL-Histidine. Using 70?l. sample linear plot with a coefficient of determination 95.79% for (5-60) mmol.L-1 while for a quadratic relation C.O.D = 96.44% for (5-80) mmol.L-1 and found that guadratic plot in more representative. Limit of detection was 31.93 ?g DL-Histidine (S/N = 3), repeatability of measurement was less that 5% (n=6). Positive and negative ion interferances was removed by using minicolume containing ion exchange resin located after injection valve position.
This paper shews how to estimate the parameter of generalized exponential Rayleigh (GER) distribution by three estimation methods. The first one is maximum likelihood estimator method the second one is moment employing estimation method (MEM), the third one is rank set sampling estimator method (RSSEM)The simulation technique is used for all these estimation methods to find the parameters for generalized exponential Rayleigh distribution. Finally using the mean squares error criterion to compare between these estimation methods to find which of these methods are best to the others
The aim of this paper is determine the concentration of the organic oxygen in some organic compounds (Aldehydes ) by the derivative neutron activation analysis technique, and the derivative of the oxygen by the nitrogen equivalent toit and the irradiation of anew sample in flounce (1.73*106 n.cm-2.s-1) by the neutron generator .Then the calculation of the radioactivity which is done by using NaI(Tl) . After that we determine the concentration of nitrogen by calibration curve that includes nitrogen compounds which have apparent chemical and physical characteristics .For comparison the result is done by using keldal method.
Background: Tumors of the oral cavity are under
estimated in general dental and medical practice,
some authors describe it as the forgetting disease,
others wondering if the attention paid to this disease
compared to its fatality (The 5-year survival rate is
about 50%) is enough for disease control? However;
this disease deserves a comprehensive assessment by
all dental and medical fields assumed to examine the
oral cavity regularly, especially otolaryngologist.
Objectives: To find out the sensitivity and specificity
of clinical examination in diagnosing oral tumors and
premalignant conditions by otolaryngologist.
Methods: Across sectional retrospective study was
conducted in the:
-study design: