Hydrodynamics and particles mixing in rectangular spouted bed with different base geometries using CFD-DEM

Zand Mohammad Karimi,Saidi Maysam 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.6

A numerical study on the flow field and particle mixing behavior in spouted beds with the aim of considering different base shapes was carried out using CFD-DEM modeling. Four spouted beds with different base angles of 180, 120, 90 and 60 degrees were compared. In order to have a qualitative and quantitative analysis on the mixing behavior, particle tracing and Lacey mixing index calculation were executed for the models. Rectangular spouted beds generate dead-zones in the corners of the system that causes less ultimate mixing index value. As the base angle decreases, the mixing index tends to increase. A mixing degree of the case with 180 degrees base angle reaches no more than 79% at the end of the simulation, which is the lowest, whereas a mixing degree of the 60 degrees base angle reaches the maximum value of 97%, which is the highest. Particle tracing conducted in these models indicates that this matter is due to the observed fact that with more incline of the base walls, particles slip more into the spout, thus entering the circulating flow. The results also indicate this increase in the slope has almost no effect on the rate which the mixing index reaches its maximum value.

SOME TOPOLOGICAL ASPECTS OF GENERALIZED GROUPS AND PSEUDONORMS ON THEM

Zand, Mohammad Reza Ahmadi,Rostami, Salimeh The Honam Mathematical Society 2018 호남수학학술지 Vol.40 No.4

In this paper, we introduce and study the notion of a pseudonorm on a generalized group. Let G be a topological generalized group and let the family $\{G_x\}_{x{\in}e(G)}$ be locally finite. Then, we show that G is completely regular. Also, some well known results are generalized.

The influence of strengthening the hollow steel tube and CFST beams using U-shaped CFRP wrapping scheme

Zand, Ahmed W. Al,Hosseinpour, Emad,Badaruzzaman, Wan Hamidon W. Techno-Press 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.66 No.2

This study investigated the behaviour of the simply supported hollow steel tube (HST) beams, either concrete filled or unfilled when strengthened with carbon fibre reinforced polymer (CFRP) sheets. Eight specimens with varied tubes thickness (sections classification 1 and 3) were all tested experimentally under static flexural loading, four out of eight were filled with normal concrete (CFST beams). Particularly, the partial CFRP strengthening scheme was used, which wrapped the bottom-half of the beams cross-section (U-shaped wrapping), in order to use the efficiency of high tensile strength of CFRP sheets at the tension stress only of simply supported beams. In general, the results showed that the CFRP sheets significantly improved the ultimate strength and energy absorption capacities of the CFST beams with very limited improvement on the related HST beams. For example, the load and energy absorption capacities for the CFST beams (tube section class 1) were increased about 20% and 32.6%, respectively, when partially strengthened with two CFRP layers, and these improvements had increased more (62% and 38%) for the same CFST beams using tube class 3. However, these capacities recorded no much improvement on the related unfilled HST beams when the same CFRP strengthening scheme was adopted.

Statistical Approach to Discovery of Factors Impacting on Emergence of Blood Cancers in Iran

Zand, Ali Mohammad,Imani, Saber,Saadati, Mojtaba,Ziaei, Robabeh,Borna, Hojat,Zaefizadeh, Mohammad,Shazad, Babak Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.12

Cancer is now the main cause of increasing mortality throughout the world. Minor alterations in the cell cycle which are inherited and not removed by apoptosis are important rsik factors. Blood cancers are asmong the types which most readily cause death. Here in this study, usual but important factors such as age, gender, Rh and ABO blood typing, weight, and platelet counts are analyzed for impact on blood cancers. Frequencies and distributions, correlations and chi-square test were utilized in order to clarify the perspective of important factors. Our statistical results show males and females to have same risk in blood cancer but A blood type (40%) along with positive Rh (73%) had the highest risk. Low platelet counts are related to more than 80% of cases. Obesity has a statistically ignorable role in blood cancer prevalence. The fact that blood cancer cases increase during the second decade of life (45.7%) which might be because of involvement of maturation processes.

GENERALIZED TOPOLOGIES ON FINITE SETS

Zand, Mohammad Reza Ahmadi The Honam Mathematical Society 2016 호남수학학술지 Vol.38 No.3

The number of topologies on a finite set is a famous open problem. In the present paper we discuss a method of obtaining the number of generalized topologies on finite sets.

Effect of timing of morphine administration during propofol - remifentanil anesthesia on the requirements of post-operative analgesia

Farid Zand,Afshin Amini,Seyed Alireza Hamidi 대한마취통증의학회 2012 Korean Journal of Anesthesiology Vol.63 No.3

Background: An important concern of intra-operative infusion of remifentanil is the possible development of acute opioid tolerance, which manifests as an increased postoperative analgesia requirement. We have examined the effect of the timing of intra operative morphine administration on the need for morphine consumption for pain control during the first 24 hours after operation. Methods: Sixty adult patients scheduled for elective open unilateral nephrolithotomy surgery were recruited for this prospective randomized double-blind study. Anesthesia was induced with 0.03 mg/kg midazolam, 1 μg/kg remifentanil, and 1.5-2 mg/kg propofol. Anesthesia was maintained with 100 μg/kg/min propofol, and 0.25 μg/kg/min remifentanil. Both groups received 0.1 mg/kg morphine intravenously at 2 different times; in the first group (group E) immediately after intubation and in the second group (group L) 20-30 min before the anticipated end of operation. Results: There was no difference in pain scores at awakening, the amount of morphine given to the 2 groups for pain control, or the time to discharge from PACU between the 2 groups. The pain scores at admission to ward and at every 4 hours thereafter, until 24 hours, were not significantly different between the 2 groups. The cumulative amount of the first 24 hours morphine consumption in the ward in E group was 28.2 ± 20.1 mg and 26.5 ± 15 mg in L group, respectively (P = 0.71). Conclusions: Early intra-operative administration of morphine compared to that of morphine in the end of surgery did not affect postoperative morphine consumption and pain scores during the first 24 hours after surgery for open nephrolithotomy. Newer pharmacologic interventions for prevention of acute tolerance of opioids seems rational (Clinical trial registration No. ACTRN: 12609000570280). Background: An important concern of intra-operative infusion of remifentanil is the possible development of acute opioid tolerance, which manifests as an increased postoperative analgesia requirement. We have examined the effect of the timing of intra operative morphine administration on the need for morphine consumption for pain control during the first 24 hours after operation. Methods: Sixty adult patients scheduled for elective open unilateral nephrolithotomy surgery were recruited for this prospective randomized double-blind study. Anesthesia was induced with 0.03 mg/kg midazolam, 1 μg/kg remifentanil, and 1.5-2 mg/kg propofol. Anesthesia was maintained with 100 μg/kg/min propofol, and 0.25 μg/kg/min remifentanil. Both groups received 0.1 mg/kg morphine intravenously at 2 different times; in the first group (group E) immediately after intubation and in the second group (group L) 20-30 min before the anticipated end of operation. Results: There was no difference in pain scores at awakening, the amount of morphine given to the 2 groups for pain control, or the time to discharge from PACU between the 2 groups. The pain scores at admission to ward and at every 4 hours thereafter, until 24 hours, were not significantly different between the 2 groups. The cumulative amount of the first 24 hours morphine consumption in the ward in E group was 28.2 ± 20.1 mg and 26.5 ± 15 mg in L group, respectively (P = 0.71). Conclusions: Early intra-operative administration of morphine compared to that of morphine in the end of surgery did not affect postoperative morphine consumption and pain scores during the first 24 hours after surgery for open nephrolithotomy. Newer pharmacologic interventions for prevention of acute tolerance of opioids seems rational (Clinical trial registration No. ACTRN: 12609000570280).

Selection of Viscous Damping Model for Evaluation of Seismic Responses of Buildings

Hamid Zand,Jalal Akbari 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.11

Users of structural analysis software commonly apply the Rayleigh damping model as a default option for analyzing of structures. When a distributed plasticity model is utilized in the numerical models, the structural responses are not found to be sensitive to the damping models; even the Rayleigh damping model leads to the reasonable seismic results. Moreover, the lower bounds and upper bounds of the demands are sensitive to the type of damping model. In this paper, the effects of viscous damping models in the seismic demands of moment and concentrically braced steel frames are carefully investigated. For this purpose, seven viscous damping models are considered using the different forms of the stiffness matrices in the finite-element modeling. The declared structural systems are modeled against several strong ground motion records in OpenSees environment. Then, the seismic responses such as drifts, accelerations and base shears are compared for the aforementioned damping models. The main result of this research is that applying Rayleigh damping model, as a default option for structural analyzing software will produce underestimated responses. In addition, it is shown that no matter which type of stiffness matrix is used in the stiffness proportional damping model. Therefore, using initial stiffness matrix is cost efficient, particularly in time-consuming nonlinear analyses.

Histological evaluation of the effect of VEGF on auto-transplanted mouse ovaries

Maryam Zand-vakili,Hussein Eimani,Afsaneh Golkar-Narenji,Poopak Eftekhari-Yazdi,Abdolhosein Shahverdi,Paul Edward Mozdziak 한국통합생물학회 2016 Animal cells and systems Vol.20 No.5

One of the most important factors affecting survival rate of ovarian follicles during transplantation period is proper vascular development. The objective of the study was to evaluate the effect of vascular endothelial growth factor (VEGF) on auto-transplanted ovarian tissue. Twenty-one-dayold female mice (n = 30) transplanted as control group and 21-day-old female mice (n = 40) were divided into 4 groups that were treated with 0.5, 1, 2 and 4 μg/mL of VEGF directly injected to auto-transplanted ovarian tissue. Twenty-one days after transplantation, mice were treated with 7.5 IU pregnant mare serum gonadotropin and human chorionic gonadotropin. Transplanted ovaries were removed and sections were prepared from transplanted tissues for staining. The most effective dosage of VEGF on transplanted tissue was determined over H&E (hematoxylin and eosin) staining results. Slides were compared using TUNEL staining and CD31 assay for the most effective dosage. The percentages of preantral and antral follicles were not significantly different between transplanted group with 4 μg/mL VEGF and non-transplanted group. Lower apoptotic areas and higher CD31 expression were observed in transplanted ovaries treated with 4 μg/mL VEGF when compared to transplanted ovaries without VEGF treatment. VEGF positively affects the quality of ovarian tissue during transplantation. Survival rate of follicles and follicular development has improved with the effect of VEGF.

Effect of zero-valent iron nanoparticles on the phytoextraction ability of Kochia scoparia and its response in Pb contaminated soil

Ali Daryabeigi Zand,Alireza Mikaeili Tabrizi 대한환경공학회 2021 Environmental Engineering Research Vol.26 No.4

Nanotechnology-supported phytoremediation is a new approach in remediation of toxic metal polluted soils, but very little is known about the effects of nanoparticles on plant survival and performance in Pb-contaminated soil. Seedlings of K. scoparia were exposed to different regimes of nanoparticles of zero-valent iron (nZVI) to investigate nZVI effects on plant growth, Pb uptake and accumulation and physiological response. Results indicated that the total Pb contents in K. scoparia treated with low to moderate concentrations of nZVI (100-500 ㎎/㎏) were higher than those in control, with the highest Pb accumulation capacity of 857.18 ㎍ per pot obtained in soil treated with 500 ㎎/㎏ nZVI. Translocation of Pb from the roots to the shoots of K. scoparia slightly increased with nZVI content of soil from 100 to 500 ㎎/㎏, while Pb transfer in K. scoparia was suppressed at higher nZVI doses. This might be related to the biomass reduction and decrease of chlorophyll content induced by high nZVI levels. Results provide a promising method to remediate Pb-polluted soil by applying proper amounts of nZVI to enhance phytoremediation performance. Selective interaction of plants and nZVI has great application prospects in the context of soil remediation.

The influence of strengthening the hollow steel tube and CFST beams using U-shaped CFRP wrapping scheme

Ahmed W. Al-Zand,Emad Hosseinpour,Wan Hamidon W. Badaruzzaman 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.66 No.2

This study investigated the behaviour of the simply supported hollow steel tube (HST) beams, either concrete filled or unfilled when strengthened with carbon fibre reinforced polymer (CFRP) sheets. Eight specimens with varied tubes thickness (sections classification 1 and 3) were all tested experimentally under static flexural loading, four out of eight were filled with normal concrete (CFST beams). Particularly, the partial CFRP strengthening scheme was used, which wrapped the bottom-half of the beams cross-section (U-shaped wrapping), in order to use the efficiency of high tensile strength of CFRP sheets at the tension stress only of simply supported beams. In general, the results showed that the CFRP sheets significantly improved the ultimate strength and energy absorption capacities of the CFST beams with very limited improvement on the related HST beams. For example, the load and energy absorption capacities for the CFST beams (tube section class 1) were increased about 20% and 32.6%, respectively, when partially strengthened with two CFRP layers, and these improvements had increased more (62% and 38%) for the same CFST beams using tube class 3. However, these capacities recorded no much improvement on the related unfilled HST beams when the same CFRP strengthening scheme was adopted.