The current study presents an experimental investigation of heat transfer and flow characteristic for subcooled flow boiling of deionized water in the microchannel heat sink. The test section consisted of a single microchannel having 300μm wide nominal dimensions and 300μm height (hydraulic diameter of 300μm). The test section formed of oxygen-free copper with 72mm length and 12mm width. Experimental operation conditions spanned the heat flux (78-800) kW/m2, mass flux (1700 and 2100) kg/m2.s at 31˚C subcooled inlet temperature. The boiling heat transfer coefficient is measured and compared with existing correlations. Also, the experimental pressure drop is measured and compared with microscale pressure drop correlations. The results showed that higher mass flux leads to higher boiling heat transfer coefficient, and the dominant mechanism is convective boiling. Also, the experimental pressure drop decrease with increasing heat flux in a single-phase region while it increases in a two-phase region. Comparing the experimental results in the experimental condition range, showed that an existing correlation provides a satisfactory prediction of heat transfer coefficient and pressure drop.
Routing is the process of delivering a packet from a source to a destination in the network using a routing algorithm that tries to create an efficient path. The path should be created with minimum overhead and bandwidth consumption. In literature, routing protocols in VANET were categorized in many ways, according to different aspects. In the present study, we prefer the classification based on the number of hops to reach the destination node. In literature, these are single-hop and multi-hops protocols. We first discuss the two types and then compare the MDDV (multi-hops protocol) with VADD (single-hop protocol). The comparison is theoretically and experimentally implemented by providing a network environment consisting of SUMO, VIENS and
... Show MoreBackground: Diabetes mellitus has been suggested
to be the most common metabolic disorder
associated with magnesium deficiency, and because
available data suggest that adverse outcomes are
associated with hypomagnesemia, it is prudent that
routine surveillance for hypomagnesemia be done
and the condition be treated whenever possible.
Aim of the study:To explore the serum Mg
concentrations of diabetic patients and healthy
controls in our locality.
Mehtods: One hundred and forty four diabetic
patients (22 with type I and 122 with type II diabetes
mellitus) recruited from the outpatient diabetes clinic
at the Specialized Center For Endocrine DiseasesBaghdad (62 patients), National Diabetes Center-Al
We try through this research to show the relationship between the crescent and the month in the Koran, and then their importance and their relationship to timing, and the timing of this relationship with people, and the significance of these timings, so we gathered verses that spoke about the family and the month, and we tried to study them in a detailed objective study, so this came The research of five subjects was the first topic introductory research and the time and month, while the remaining four detectives on the verses that talked about the timing of the month, and we have explained the relationship of this timing with people and the significance of these times.
The present work aims to study forward osmosis process using different kinds of draw solutions and membranes. Three types of draw solutions (sodium chloride, sodium formate, and sodium acetate) were used in forward osmosis process to evaluate their effectiveness with respect to water flux and reverse salt flux. Experiments conducted in a laboratory-scale forward osmosis (FO) unit in cross flow flat sheet membrane cell. Three types of membranes (Thin film composite (TFC), Cellulose acetate (CA), and Cellulose triacetate (CTA)) were used to determine the water flux under osmotic pressure as a driving force. The effect of temperature, draw solution concentration, feed and draw solution flow rate, and membrane types, were studied with
... Show MoreThe present study was conducted on the Iraqi Pin-tailed Sandgrouse (Pterocles alchata) to study the lung's morphological description and histological structure. This study was used 5 samples of adult male sandgrouse bird. The birds were dissected. The lungs were removed from the coelomic cavity, cleaned to remove impurities, and photographed to describe their morphological features. The samples were fixed using formalin (10%) solution for 36-48 hours and then preserved in alcohol (70%) to prepare the microscopic slides. The results showed that the lung of the Iraqi sandgrouse bird is red in color, has a trapezoidal shape and has three surfaces (costal, visceral, and vertebral). The costal surface shows ribs impressions that extend f
... Show MoreThermomechanical analysis (TMA) and differential scanning calorimetry (DSC) are used to investigate the effect of molding and annealing of polyester on the behavior of thermal expansion and crystallization since these factors play role in the reprocessing or recycling of the polymer. The dynamic mode of the TMA provides enhanced characterization information about the polyester since it separates the transitions into reversible and irreversible signals, and also reveals the progress of the amorphous regions as the polyester loses strength with the increasing temperature approaching melting. Slow cooling after annealing brings crystallization that may be attributed to molecular chain straightening due to orientation.
The Manganese doped zinc sulfide nanoparticles of the cubic zinc blende structure with the average crystallite size of about 3.56 nm were synthesized using a coprecipitation method using Thioglycolic Acid as an external capping agent for surface modification. The ZnS:Mn2+ nanoparticles of diameter 3.56 nm were manufactured through using inexpensive precursors in an efficient and eco-friendly way. X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy are used to examine the structure, morphology and chemical composition of the nanoparticles. The antimicrobial activity of (ZnS:Mn2+) nanocrystals was investigated by measuring the diameter of inhibition zone using well diffusion mechanism
... Show MoreThis paper contains an equivalent statements of a pre- space, where are considered subsets of with the product topology. An equivalence relation between the preclosed set and a pre- space, and a relation between a pre- space and the preclosed set with some conditions on a function are found. In addition, we have proved that the graph of is preclosed in if is a pre- space, where the equivalence relation on is open.
On the other hand, we introduce the definition of a pre-stable ( pre-stable) set by depending on the concept of a pre-neighborhood, where we get that every stable set is pre-stable. Moreover, we obtain that
... Show More