A pioneering idea for increasing the thermal performance of heat transfer fluids was to use ultrafine solid particles suspended in the base fluid. Nanofluids, synthesized by mixing solid nanometer sized particles at low concentrations with the base fluid, were used as a new heat transfer fluid and developed a remarkable effect on the thermophysical properties and heat transfer coefficient. For any nanofluid to be usable in heat transfer applications, the main concern is its long-term stability. The aim of this research is to investigate the effect of using four different surfactants (sodium dodecyl benzene sulfonate (SDBS), sodium dodecyl sulfate (SDS), cetyl trimethylammonium bromide (CTAB), and gum Arabic (GA)), each with three different concentrations, and five ultrasonication times (15, 30, 60, 90, and 120 min) on the stability of water-based graphene nanoplatelets (GNPs) nanofluids. In addition, the viscosity and thermal conductivity of the highest stability samples were measured at different temperatures. For this aim, nineteen different nanofluids with 0.1 wt% concentration of GNPs were prepared via the two-step method. An ultrasonication probe was utilized to disperse the GNPs in distilled water. UV–vis spectrometry, zeta potential, average particle size, and Transmission Electron Microscopy (TEM) were helpful in evaluating the stability and characterizing the prepared nanofluids. TEM and zeta potential results were in agreement with the UV–vis measurements. The highest nanofluid stability was obtained at 60-min ultrasonication time. The prepared water-based pristine GNPs nanofluids were not stable, and the stability was improved with the addition of surfactants. The presence of SDBS, SDS, and CTAB surfactants in the nanofluids resulted in excessive foam. The best water-based GNPs nanofluid was selected in terms of better stability, higher thermal conductivity, and lower viscosity. From all the samples that were prepared in this research, the (1–1) SDBS–GNPs sample with 60-min ultrasonication showed the highest stability (82% relative concentration after 60 days), the second better enhancement in the thermal conductivity of the base fluid (8.36%), and nearly the lowest viscosity (7.4% higher than distilled water).
A survey of blood parasites among members of two species of Iraqi babblers Timaliidae,
Turodoides caudatus salvadori (de Fillipi, 1865) and Turdoides alterostris (Hartert, 1909)
was carried out in the middle and south of Iraq. Two species of haematozoa were recovered,
Haemoproteus turdoidus sp. nov. and Plasmodium relictum Grassi &Felleti. The description
of the new taxon is provided and discussed with pertinent literature.
Vacuum gas oil (611-833)K was distilled from Kirkuk crude oil, which was obtained by blending the following fraction,
light vacuum gas oil (611 - 650) K, medium vacuum gas oil (650-690)K, heavy vacuum gas oil (690-727)K and very
heavy vacuum gas oil (727-833)K.
The vacuum gas oil was hydrotreated on a commercial cobalt-molybdenum alumina catalyst presulfied at specified
condition in a laboratory trickle bed reactor. The reaction temperature varied from (583-643)K over liquid hourly space
velocity ranging between (1.5-3.75)h-1 , Hydrogen pressure was kept constant at 3.5 MPa with a hydrogen to oil ratio
of about 250 L/L
The conversion results for desulfurization appeared to obey the second order kinetics. According to
ABSTRACT
Ticagrelor is an orally administered antiplatelet medicine, direct-acting P2Y12-receptor antagonist. Ticagrelor binds reversibly and noncompetitively to the P2Y12 receptor at a site distinct from that of the endogenous agonist adenosine diphosphate (ADP). Inhibition of platelet aggregation stimulated by ADP is a commonly used pharmacodynamic parameter for P2Y12-receptor antagonists.
Ticagrelor is a crystalline powder with an aqueous solubility of approximately 10?g/mL at room temperature.
... Show MoreObjectives: to evaluate the role of conservative, decompression, spine fixation in management of closed spinal injury.
Methods: The study was conducted at Specialized Surgical hospital and Al-Kadhemayia Teaching Hospital, in the period between July 2003 and July 2005.The study included 61 patients categorized Into many groups according level of vertebral injury (cervical, cervicodorsal, dorsal, dorsolumbar, Lumbar and lumbosacral), type of injury (compressed fracture, burst fracture and fracture dislocation) And according the severity into three groups as G1( complete motor paralysis and sensory loss ) G2 ( complete motor paralysis and incomplete sensory loss) and G3 ( incomplete motor paralysis And incomplete sensory loss ).The metho
The present work is concerned with the finding of the optimum conditions for biochemical wastewater treatment for a local tannery. The water samples were taken from outline areas (the wastewater of the chrome and vegetable tannery) in equal volumes and subjected to sedimentation, biological treatment, and chemical and natural sedimentation treatment.
The Box-Wilson method of experimental design was adopted to find useful relationships between three operating variables that affect the treatment processes (temperature, aeration period and phosphate concentration) on the Biochemical Oxygen Demand (BOD5).
The experimental data collected by this method were successfully fitted to a second order polynomial mathematical model. The most fa
The mechanical design of elevator elements is always performed by international standards. The engineer selects the appropriate elements of elevator according to catalogues without knowing scientific details. Therefore, a theoretical analysis is achieved at two operating conditions for guide rails (1) safety gear operation, and (2) running condition with the loads unevenly distributed on the elevator car. The guide rail is considered a continuous beam with variable supports. Then the British code is listed showing the equations used in it.
The theoretical equations showed that guide rails are never subjected to stress in simultaneous combined buckling and bending in the plane, where the bending moment is exerted. It is always a c
... Show MoreIntroduction: Dental pulp tissue contains many undifferentiated mesenchymal cells, which have the ability to differentiate into different specialized cells. Induced pluripotent stem cells have been developed by various growth factors. The present study was designed to evaluate the effect of application of a combination BMP2/TGF β1 as capped material for traumatic pulp in osteoporotic rat. Materials and Methods: Twelfth female rats (6 normal rat and other 6 osteoporotic rat)., their maxillary anterior teeth subjected to mechanical traumatized pulptomy, the left tooth has speared without treatment, while the right tooth capped with application of 0.5 μl of BMP2 and 0.5μl of TGF β1 .Evaluation of histological changes includes scoring of pu
... Show MoreThe study aims at identifying the morphological and psycho-socio-economic qualities wished to be in a life partner among a sample of Palestinian youth. The total sample was (231) and consisted of (83) male and (148) female students. Each student presented a detailed report on the qualities he/she wished to be in life partner. The study used the descriptive approach and content analysis method. The validity and stability of the analysis were calculated. The results showed eight qualities in both groups: physical, psychological, emotional, social, intellectual, familial, economic and academic. Female students were found to have more variations than male students in terms of the qualities preferable in the life partner. Male students
... Show MoreThe study aimed to know the effect of the use alcoholic ethanol extraction of Boswellia Carterii In prolonging the period of preservation cooled ground meat in 4C for 6 days, it has been mixing ground meat with 150,300,450 mg/ml of alcoholic extract Consecutive, Where (0 was the control sample), All samples were stored separately for 0 , 3 , 6 days in Refrigerator temperature 4 C, Conducted by some microbial tests, Results have shown that mixing the ground meat with Boswellia Carterii extraction Led to prolong the storage of meat for 6 days at 4 C .and the Best result came when adding alcoholic ethanol extract of Boswellia Carterii by 450mg/ml Which Equal 0.9 g ,that reducing microbial load more higher than 150&300 mg/ml. All of thes
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