Physical and chemical adsorption analyses were carried out by nitrogen gas using ASTM apparatus at 77 K
and hydrogen gas using volumetric apparatus at room temperature respectively. These analyses were used for
determination the effect of coke deposition and poisoning metal on surface area, pore size distribution and
metal surface area of fresh and spent hydrodesulphurization catalyst Co-Mo\Al2O3 .
Samples of catalyst (fresh and spent) used in this study are taken from AL-Dura refinery.
The results of physical adsorption shows that surface area of spent catalyst reduced to third compare with
fresh catalyst and these catalysts exhibit behavior of type four according to BET classification ,so, the pores
of these samples are cylindrical, and the pores of fresh catalyst suffers during the hydrodesulphurization .
The result of chemical adsorption shows that the metal surface area of fresh catalyst is 50.72 m2/g while it
reduced to 39.04 m2/g for spent catalyst.
The present study attempts to shed light on some biological aspects and characteristics of Piaractus brachypomus, including some biometrics, phenotypic and feeding pattern that characterizes this species. Besides, the study touches upon the body shape and the Otolith. These fish species have recently been seen frozen in the Iraqi local market. The standard length of fish specimens in this study reach 26.55cm it exceeded the specimens of Pacu fish collected from other studies from other countries, As well the specimens weight was 632gm it exceeded other studies mentioned in this manuscript. As the irregularity in the distribution of teeth rows, especially in the lower jaw was clear in our specimens. The average weight of some skull b
... Show MoreThe anatomic characteristics of the leaves of 22 taxa of Stachys L. representing seven of the currently recognized sections distributed in northern Iraq, were examined. The study did not found any variations in the characteristics of the stomata system of the leaves.Therewere variations with a good taxonomic value in other anatomic characteristics.Thevariations in characters of the mesophyll tissue in S.kurdica var.brevidens Bom ex Bhattacharjeewas bifacial but in S.kurdica var.kurdica Boiss. & Hohen.was unifacial .The study also found that the taxa S.benthamiana Bioss., S.lanigera (Bornm.) Rech.f. andS.kotscyi Bioss. with 3 vascular bundles in the middle vein while the taxa S.ballotiformis Vatke., S.megalodonta Hausskn. &Bo
... Show MoreBN Rashid
Background: The use of electronic apex locators for working length determination eliminates many of the problems associated with the radiographic measurements (interference of anatomical structures, errors in projection such as elongation or shortening, and lack of three-dimensional representation). Its most important advantage over radiography is that it measures the length of the root canal to the apical constriction, not to the radiographic apex. The aim of this study was to assess the accuracy of a new fifth generation apex locator (Joypex 5) in recording the apical constriction and comparing it with a third generation apex locator (Root ZX) in vitro. Materials and method: Twenty four single-rooted sound human premolars, extracted for t
... Show MoreIn this study, the effect of the thermal conductivity of phase change material (PCM) on the performance of thermal energy storage has been analyzed numerically. A horizontal concentric shell-and-tube latent heat thermal energy storage system (LHTESS) has been performed during the solidification process. Two types of paraffin wax with different melting temperatures and thermal conductivity were used as a PCM on the shell side, case1=0.265W/m.K and case2=0.311 W/m.K. Water has been used as heat transfer fluid (HTF) flow through in tube side. Ansys fluent has been used to analyze the model by taking into account phase change by the enthalpy method used to deal with phase transition. The numerical simulatio
... Show MoreBN Rashid, Social Sciences, 2022
Secnidazole was linked with ciprofloxacin as mutual prodrugs to get antibiotics with broader spectrum of activity, improved physicochemical properties and given by single dose to improve patient’s compliance. Furthermore, they provide structural modifications to overcome bacterial adaptation. The structures of the synthesized compounds were confirmed using FT-IR, mass spectrometry, elemental microanalysis (CHNO) and some physiochemical properties. This modification was led to an increase in Log P values for Mutual I (Log P 1.114) and Mutual II (Log P 1.97) compared with its values for Secnidazole (Log P -0.373) and ciprofloxacin (Log P -0.832). The solubility of prodrugs had been determined in different media, Mutual II showed 1
... Show MoreCdS films were prepared by thermal evaporation at pressure (10-6torr) of 1μm thickness onto glass substrate by using (Mo) boat. The optical properties of CdS films, absorbance, transmittance and reflectance were studied in wavelength range of (300-900)nm. The refractive index, extinction coefficient, and absorption coefficient were also studied. It's found that CdS films have allowed direct and forbidden transition with energy gap 2.4eV and 2.25eV respectively and it also has high absorption coefficient (α >104cm-1).