The lead-acid battery has become so dependable in its used applications of automobile starting, emergency lighting and telecommunications, which left an impression that no further investigation is necessary or desirable. While there has been slow continuous improvements in lead-acid battery performance and mainly limited to design and material engineering. This work is mainly devoted to the properties of the active mass of the positive electrode and the acid/water ratio during the manufacturing process. A field study is carried out at the State Battery Manufacturing Company located in Baghdad, to prepare batches of lead mono-oxide with predefined quantities of liquid additives (i.e. sulfuric acid and water). Quality control and laboratory routine analysis using X-ray diffraction, porosimeter and BET techniques, as well as density, penetration tests of residual lead content ware conducted during the batch process. After the assembling of the positive plates produced during this research into the final product, final testing including electrical capacity and dry charging were performed. It was concluded from the results obtained, that the effective H2SO4/H2O ratio and hence H2SO4/PbO ration and paste density with α/β-PbO2, are the limiting factors of the electrical capacity and durability of the batteries concerned.
Brainstorming is one of the fundamental and necessary concepts for practicing the auditing profession, as auditing standards encouraged the implementation of brainstorming sessions to reach reasonable assurance about the validity of the evidence and information obtained by the auditor to detect fraud, as the implementation of brainstorming sessions and the practice of professional suspicion during the audit process lead to increase the quality of auditing and thus raise the financial community's confidence in the auditing profession again after it was exposed to several crises that led to the financial community losing confidence in the auditing profession.
The research aims to explain the effect of brain
... Show MoreThe specifications of lubricating oil are fundamentally the final product of materials that have been added for producing the desired properties. In this research, spherical nanoparticles copper oxide (CuO) and titanium oxides (TiO2) are added to SAE 15W40 engine oil to study the thermal conductivity, stability, viscosity of nano-lubricants, which are prepared at different concentrations of 0.1%, 0.2%, 0.5%, and 1% by weight, and also their pour point, and flash point as five quality parameters. The obtained results show that CuO nanoparticles in all cases, give the best functionality and effect on engine oil with respect to TiO2. With 0.1 wt. % concentration, the thermal conductivity of CuO/oil and TiO2/
... Show MoreA polycrystalline CdTefilms have been prepared by thermal evaporation technique on glass substrate at room temperature. The films thickness was about700±50 nm. Some of these films were annealed at 573 K for different duration times (60, 120 and 180 minutes), and other CdTe films followed by a layer of CdCl2 which has been deposited on them, and then the prepared CdTe films with CdCl2 layer have been annealed for the same conditions. The structures of CdTe films without and with CdCl2 layer have been investigated by X-ray diffraction. The as prepared and annealed films without and with CdCl2 layer were polycrystalline structure with preferred orientation at (111) plane. The better structural pr
... Show MoreA computerized investigation has been carried out on the design of six electrodes electrostatic lenses used in electron gun application. The Finite-Element Method (FEM) was used in the solution of Laplace equation for determine the axial potential distribution. The electron trajectory under zero magnification condition. The optical properties, spherical and chromatic aberrations, the object and image focal length and object and image position are calculated. A very good futures for the electron gun with these lenses have been computed where are a beam current of 8.7*10-7A can be supplied using cathode tip of radius 10nm.
The current research aims to know the effect of Needham's constructivist model on the achievement of third-year students in the Life Sciences Department in the teaching methods subject. To achieve the research objectives, the experimental method was followed for the experimental and control groups with dimensional measurement of the achievement variable of the teaching methods subject. The research sample included (62) students in the third year of the Life Sciences Department, distributed into two equal groups in the variables (self-assessment of learning methods - chronological age in years - intelligence level - previous information). To measure the level of students' achievement, an achievement test was constructed consisting of (40) te
... Show MoreAll businesses seek to improve their levels of profits through various means, most notably their marketing channels, which ensure the delivery of their products to their customers in a safe manner in a timely manner. It considers losses to a minimum and that insurance companies place great interest in marine insurance losses because they often constitute huge amounts compared to other losses, hence the problem of research, which is centred on the type and size of the impact owned by the channel The Iraqi insurance company was chosen to be applied according to the intentional sample method because this company is closely related to the subject matter. The research has reached a set of conclusions, most notably that the choice of i
... Show MoreAbstract: Two different shapes of offset optical fiber was studied based on coreless fiber for refractive index (RI)/concentration (con.) measurement, and compare them. These shapes are U and S-shapes, both shapes structures were formed by one segment of coreless fiber (CF) was joined between two single mode (SMF) lead in /lead out with the same displacement (12.268µm) at both sides, the results shows the high sensitive was achieved in a novel S-shape equal 98.768nm/RIU, to our knowledge, no one has ever mentioned or experienced it, it’s the best shape rather than the U-shape which equal 85.628nm/RIU. In this research, it was proved that the offset form has a significant effect on the sensitivity of the sensor. Addi
... Show MoreSome microorganisms can produce nanocellulose, which is known as bacterial nanocellulose (BNC); the most active bacterial producer is acetic acid bacteria (AAB), which is a gram-negative, motile and obligate aerobic belongs to the family Acetobacteraceae. Bacterial nanocellulose has excellent attention in medical (surgical domain), industrial and pharmaceutical fields because of its flexible properties, characteristics and advantages. So, in this study, the AAB (5AC) isolate was isolated from apple vinegar. The production of BNC was performed by using a natural medium called palm dates liquid medium, the produced bacterial Cellulose was purified by using the sodium hydroxide method; it was observed that the wet weight of the BNC was a
... Show MoreAn acidic environment causes surface changes of resin composites. Filler particlesize and filler distribution also have a direct effect on these surface changes. This invitro study evaluated the influence of Pepsi Cola drink on the surface roughness ofComposan LCM and Composan Ceram over time. Sixteen disc shaped specimens(10mm diameter, 2mm thickness) of each resin composite were fabricated, therebyforming two groups (n= 8). Surface roughness (Ra) was analyzed after 24 hrs beforeexposure to beverage. The specimens were submitted to a five minutes immersion inPepsi Cola three times daily interrupted by immersion in deionized distilled water (37C˚). Surface roughness measurements were done at 10, 30, and 60 days intervals. Datawere
... Show MoreThe effect of applied current on protection of carbon steel in 0.1N NaCl solution (pH=7) was investigated under flow conditions (0-0.262 m/s) for a range of temperatures (35-55°C) using rotating cylinder electrode. Various values of currents were applied to protect steel from corrosion, these were Iapp.=Icorr., Iapp.=2Icorr. and Iapp.=2.4Icorr. under stationary and flow conditions. Corrosion current was measured by weight loss method. The variation of protection potential with time and rotation velocity at various applied currents was assessed. It is found that the corrosion rate of carbon steel increases with rotation velocity and
has unstable trend with temperature. The protection current required varies with temperature and it inc