Improved Kerosene Quality with the Use of a Gamma Alumina Nanoparticles Supported Zinc Oxide Catalyst in a Digital Batch Baffled Reactor: Experiments and Process Modelling

Jasim I. Humadi,Ghassan Hassan Abdul Razzaq,Luay Ahmed Khamees,Mustafa A. Ahmed,Liqaa I. Saeed 한국화학공학회 2023 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.61 No.2

To create an environmentally sustainable fuel with a low sulfur concentration, requires alternative sulfur removal methods. During the course of this study, a high surface gamma alumina-supported ZnO nanocatalyst with a ZnO/-Al2O3 ratio of 12% was developed and tested for its ability to improve the activity of the oxidative desulfurization (ODS) process for the desulfurization of kerosene fuel. Scanning electron microscopy (SEM) and Brunauer-Emmett- Teller (BET) were used to characterize the produced nanocatalyst. In a digital batch baffled reactor (20~80 min), the effectiveness of the synthesized nanocatalyst was tested at different initial concentrations of dibenzothiophene (DBT) of 300~600 ppm, oxidation temperatures (25~70 ℃), and oxidation periods (0.5, 1, and 2 hours). The baffles included in the digital baffled batch reactor resist the swirling of the reaction mixture, thus facilitating mixing. The ODS procedure yielded the maximum DBT conversion (95.5%) at 70 ℃ with an 80-minute reaction time and an initial DBT level of 600 ppm. The most precise values of kinetic variables were subsequently determined using a mathematical modelling procedure for the ODS procedure. The average absolute error of the simulation findings was less than 5%, demonstrating a good degree of agreement with the experimental results acquired from all runs. The optimization of the operating conditions revealed that 99.1% of the DBT can be removed in 140 minutes.

The role of internal architecture in producing high-strength 3D printed cobaltchromium objects

Abdullah Jasim Mohammed,Ahmed Asim Al-Ali 대한치과보철학회 2024 The Journal of Advanced Prosthodontics Vol.16 No.2

Purpose. The objectives of the current study were to estimate the influence of self-reinforced hollow structures with a graded density on the dimensional accuracy, weight, and mechanical properties of Co-Cr objects printed with the direct metal laser sintering (DMLS) technique. Materials and methods. Sixty-five dog-bone samples were manufactured to evaluate the dimensional accuracy of printing, weight, and tensile properties of DMLS printed Co-Cr. They were divided into Group 1 (control) (n = 5), Group 2, 3, and 4 with incorporated hollow structures based on (spherical, elliptical, and diamond) shapes; they were subdivided into subgroups (n = 5) according to the volumetric reduction (10%, 15%, 20% and 25%). Radiographic imaging and microscopic analysis of the fractographs were conducted to validate the created geometries; the dimensional accuracy, weight, yield tensile strength, and modulus of elasticity were calculated. The data were estimated by one-way ANOVA and Duncan’s tests at P < .05. Results. The accuracy test showed an insignificant difference in the x, y, z directions in all printed groups. The weight was significantly reduced proportionally to the reduced volume fraction. The yield strength and elastic modulus of the control group and Group 2 at 10% volume reduction were comparable and significantly higher than the other subgroups. Conclusion. The printing accuracy was not affected by the presence or type of the hollow geometry. The weight of Group 2 at 10% reduction was significantly lower than that of the control group. The yield strength and elastic modulus of the Group 2 at a 10% reduction showed means equivalent to the compact objects and were significantly higher than other subgroups.

Oscillatory shearing behavior of rocket leaves powder incorporated dough

Abdulwahab Salem Almusallam,Jasim Ahmed,Shamsun Nahar,Siby Chacko 한국유변학회 2016 Korea-Australia rheology journal Vol.28 No.2

Dough blended with rocket leaves powder was subjected to small and large amplitude oscillatory shears. Small amplitude oscillatory shear data were fitted to a discrete relaxation model of elastic solids and to a critical gel model. The small amplitude relaxation spectrum was thereafter used to calculate the LAOS predictions of various large deformation models. The LAOS theoretical calculations using the Phan-Thien model showed good agreement with the first harmonic stress data, and only qualitative agreement with the third and the fifth harmonic stress values. Lissajous curves showed dissimilarity in shape between the experimental data and Phan-Thien model. The network model of Sim et al. (2003). Did not have the butterfly shape displayed in the Phan-Thien model, but it provided a worse fit to stress harmonics than the Phan- Thien model. An improved damage function was proposed, where time effect on network damage was taken into consideration, and fits to stress harmonics and to Lissajous stress-strain curves were significantly improved.

Relationship between liver iron concentration determined by R2-MRI, serum ferritin, and liver enzymes in patients with thalassemia intermedia

Hayder Al-Momen,Shaymaa Kadhim Jasim,Qays Ahmed Hassan,Hayder Hussein Ali 대한혈액학회 2018 Blood Research Vol.53 No.4

BackgroundIron overload is a risk factor affecting all patients with thalassemia intermedia (TI). We aimed to determine whether there is a relationship of serum ferritin (SF) and alanine ami-notransferase (ALT) with liver iron concentration (LIC) determined by R2 magnetic reso-nance imaging (R2-MRI), to estimate the most relevant degree of iron overload and best time to chelate in patients with TI.MethodsIn this cross-sectional study, 119 patients with TI (mean age years) were randomly se-lected and compared with 120 patients who had a diagnosis of thalassemia major (TM). Correlations of LIC, as determined by R2-MRI, with SF and ALT levels, were assessed in all participants. A P-value <0.05 was considered statistically significant. ResultsSF and LIC levels were lower in patients with TI than in those with TM; only ferritin values were significant. We found a statistically significant relationship between SF and LIC, with cut-off estimates of SF in patients with TI who had splenectomy and those who entered puberty spontaneously (916 and 940 ng/mL, respectively) with LIC >5 mg Fe/g dry weight (P<0.0001). A significant relationship was also found for patients with TI who had ele-vated ALT level (63.5 U/L), of 3.15 times the upper normal laboratory limit, using a cut-off for LIC ≥5 mg Fe/g dry weight.ConclusionWe determined the cut-off values for ALT and SF indicating the best time to start iron chela-tion therapy in patients with TI, and found significant correlations among iron overload, SF, and ALT.

Can parents prevent tooth loss related to dental avulsion? An assessment of knowledge related to permanent teeth

Sivaramakrishnan Gowri,Abawi Deena,Shoaib Fatima Mohammad,Bucheery Fatema,Salman Ahmed Ali,Kadhem Majeed Jasim,AlSulaiti Fatema,Alsobaiei Muneera,AlSalihi Leena 대한외상학회 2023 大韓外傷學會誌 Vol.36 No.1

Purpose: Dental avulsion injuries have a poor prognosis that largely depends on the immediate steps taken to manage the avulsed tooth. A lack of knowledge about the initial management can lead to tooth loss, with further adverse implications for esthetics, phonetics, and overall growth and function. Hence, the present study aimed to assess parents’ knowledge regarding dental avulsion and the variables associated with their knowledge of avulsion injuries. Methods: A series of closed-ended questions on parents’ knowledge regarding avulsion, such as immediate management, storage media, handling, and urgency of visiting the dentist, was asked. Univariate associations between the outcomes were assessed using the Pearson chi-square test. The chi-square goodness-of-fit test was used to check whether the sample data were representative of the population. Results: In total, 211 mothers and 149 fathers were included, of whom 46.7% had experienced dental trauma during their own childhood. Sixty-one percent of mothers believed that they knew everything necessary about tooth avulsion and its management. A significant number of participants who thought that they had a good level of knowledge about avulsion chose water, tissue, or paper wrap to transport the tooth, and preferred tap water, alcohol, or antiseptic to clean the avulsed tooth.Conclusions: Both mothers and fathers had poor knowledge about tooth avulsion, indicating that there is an immediate need for educational programs focusing on this issue. Since a substantial proportion of participants believed incorrect information, it is vital to disseminate accurate information.