Thermal performance of closed wet cooling tower has been investigated experimentally and theoretically
in this work. The theoretical model based on heat and mass transfer equations and heat and mass transfer balance equations which are established for steady state case. A new small indirect cooling tower was used for conducting experiments. The cooling capacity of cooling tower is 1 kW for an inlet water temperature of 38oC, a water mass velocity 2.3 kg/m2.s and an air wet bulb temperature of 26oC. This study investigates the relationship between saturation efficiency, cooling capacity and coefficient of performance of closed wet cooling tower versus different operating parameters such wet-bulb temperature, variable air-spray water flow ratio and cooling water inlet temperature. Results indicate that the capacity and saturation efficiency was found close to the related experimental results. Good agreement was obtained between the theoretical results and experimental measurements for the performance of small cooling tower.
Watermelon is known to be infested by multiple insect pests both simultaneously and in sequence. Interactions by pests have been shown to have positive or negative, additive or non additive, compensatory or over compensatory effects on yields. Hardly has this sort of relationship been defined for watermelon vis-à-vis insect herbivores. A 2-year, 2-season (4 trials) field experiments were laid in the Research Farm of Federal University Wukari, to investigate the interactive effects of key insect pests of watermelon on fruit yield of Watermelon in 2016 and 2017 using natural infestations. The relationship between the dominant insect pests and fruit yield were determined by correlation (r) and linear regression (simple and multiple) analys
... Show MoreReactive Powder Concrete (RPC) could be considered as the furthermost significant modern high compressive strength concrete. In this study, an experimental investigation on the impact of micro steel fiber volume fraction ratio and gamma ray irradiation duration influence upon the compressive strength of RPC is presented. Three volume fraction ratios (0.0, 1.0 and 1.5) % was implemented. For each percentage of the adopted fiber ratios, six different irradiation duration was considered; these are (1, 2, 3, 4, 5 and 6) days. Gamma source (Cs-137) of energy (0.662) MeV and activity (6) mci was used. In a case of zero volume fraction ratio, the experimental results showed that gamma ray had a significant influence on the reducing of the
... Show MoreBackground: Fertility plays great role in animal reproduction since high quality semen improves sheep industry reproduction. The current worldwide data revealed the closely related of CNP to reproductive function of rams. Aims: Evaluation the effect of CNP on cooled sperms using the traditional and molecular assays. Methods: Totally, 20 testicular samples were collected, processed to obtain the semen samples and divided into two parts; one treated with the suitable dose of CNP and the otherserved as a control. Sperm samples of both groups were cooled for 3 days and tested at 0 0h, 24h, 48h and 72h. Results: The findings revealed that the suitable dose of CNP-treated sperms was 0.0110-13. Values individual motility, live sperm
... Show MorePoly vinyl alcohol has been studied for its ability to form crystallites by using annealing method. Semicrystalline films of poly vinyl alcohol (PVA) were prepared by casting 11.5 wt. % and 13 wt. % PVA aqueous solution onto glass slides at annealing temperature range 90 -120°C and duration time 15- 60 minute. This allowed the macromolecules to form crystallites, small regions of folded and compacted chains separated by amorphous regions where single PVA chain may pass through several of these crystallites. Degree of crystallinity of PVA films (hydrogels) was determined by method of density; on the other hand the swelling behavior was conducted by the determination of water uptake, wet degree of crystallinity, gel fraction and solubilit
... Show MoreThe current experiment was conducted to explore the effect of soil crude oil ( crude oil ) pollution on some wood properties of Casuarina equisetifolia. Four levels of pollution were applied on 40 (one-year) old seedlings . Measurements were taken by cutting the trees after two growth seasons from date of pollution .The studied Properties were fiber length, diameter, wall thickness, and specific gravity of external and internal wood. Results showed an adverse effect of pollution on fiber diameter more than on fiber length. While wall thickness did not affect. Fiber dimensions of external wood showed higher values than that of internal one, especially for fiber
... Show MoreThe ability of different alumina-grafted particles was examined for adsorption of phenol and p-chlorophenol under different conditions (i.e. concentrations and temperatures). Dispersion stability of alumina in liquid medium (water) was studied using settling under gravity technique. The result shows the settling initial rate of the alumina-grafted acrylic acid particles was faster than initial rate of settling when alumina-graft acrylic acid monomer adsorbed phenol and p-chlorophenol and vice versa to the alumina-graft poly(acrylic acid) polymer.
Thermodynamic parameters values (DG, DS, DH) were calculated for adsorption processes of phenol and p-chlorophenol adsorbed onto different surfaces. The
... Show MoreMetal enhanced fluorescence (MEF) is an unequaled phenomenon of metal nanoparticle surface plasmons, when light interacts with the metal nanostructures (silver nanoparticles) which result electromagnetic fields to promote the sensitivity of fluorescence. This work endeavor to study the influence of silver nanoparticles on fluorescence intensity of Fluoreseina dye by employment mixture solution with different mixing ratio. Silver nanoparticles had been manufactured by the chemical reduction method so that Ag NP layer coating had been done by hot rotation liquid method. The optical properties of the prepared samples (mixture solution of Fluoreseina dye solutions and colloidal solution with 5 minutes prepared of Ag NPs) tested by using UV-V
... Show MoreThe work concerned with studying the effect of (SiO2) addition as a
filler on the adhesive properties of (PVA). Samples were prepared as
sheets by using casting method. The mechanical properties showed
that increase in tensile strength from (34MPa) to (68MPa) when
(SiO2) added to (PVA). The adhesive strength showed that joint
properties depend upon specific adhesive characteristic of material
(PVA) and (SiO2\PVA)composites at different concentrations (1.5%,
2.5%, 3.5%, 4.5wt%), the cohesive strength of the adhesive material,
the joint design, and adherent type (Sponge Rubber(SR), Natural
leather (NL), Vulcanized Rubber(VR), and Cartoon). The results
proved the tensile strength increased with (SiO2) ratio, so
A field experiment was carried out to find out the effect of some herbicides(Pallas, Crash, U46) on the companion weed to three cultivars of the oat crop (Shefa, Hamel, and Pimula) and the yield and its components of these cultivars. The results showed the superiority of the two treatments of spraying weed herbicides (T1 and T2 ) by giving the best results, as they recorded the lowest number of weed plants after 30 days of spraying reached 1.44 and 1.67 plant/m2 . Besides, the lowest weed dry weight was 0.11 and 0.00 g/m2, and the highest inhibition percentage in dry weight was 98.44% and 100.0% of the two treatments, respectively. The treatment T2 was also superior by giving the highest control percentage of 93.28% compared to the compari
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