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| 1 | Oxidative coupling of methane over (Na_2WO_4+Mn or Ce)/SiO_2 catalysts:In situ measurement of electrical conductivity显示文摘The effects of manganese oxide or ceria promoters on the performance of Na2WO4/SiO2 catalysts for oxidative coupling of methane (OCM) are reported. The OCM reaction was performed in a continuous-flow microreactor at 800 ℃, atmospheric pressure and under GHSV = 13200 ml gC-1at h-1. Catalysts were characterized by in situ conductivity measurement, FT-IR spectroscopy, XRD, SEM and temperature programmed reduction analysis. Manganese oxide promoted Na2WO4/SiO2 is considered as one of the active and selective catalysts for OCM reaction. Ceria with high oxygen storage capacity is selected as a proper oxygen activator, providing a higher concentration of the oxy-anion species which is suitable for OCM reaction and compared with manganese oxide. Electrical conductivity of the catalysts was measured in OCM reaction under oxidizing atmosphere, i.e. in the absence of methane. It was found that the trimetallic catalysts, i.e. the catalysts having sodium, tungsten and Mn or Ce species, exhibited similar crystalline structures and morphologies, which lead to suitable bulk properties for the formation of an active and selective catalyst. However, tungsten had significant effect on the texture and redox properties of the catalysts. It was also shown that the crystalline structure of the bimetallic (Na+Mn or Ce)/SiO2 samples was quite different. This reveals that the metal oxides have significant effect on the extent of crystallization, taking place in the course of interaction of sodium with silica support. Similar conductivities and catalytic performances of (Na2WO4+Mn or Ce)/SiO2 catalysts propose that the ability of Na2WO4/SiO2 for utilizing oxy-anions formed in presence of different metal oxides is limited. | Zeinab Gholipour Azim Malekzadeh Reza Hatami Yadollah Mortazavi Abasali Khodadadi | 2010 | Journal of Natural Gas Chemistry2010，19，1： | 3 |
| 2 | Evaluation of the risk factors associated with emergency department boarding:A retrospective cross-sectional study显示文摘Purpose Boarding is a common problem in the emergency department(ED)and is associated with poor health care and outcome.Imam Khomeini Hospital is the main healthcare center in Urmia,a metropolis in the northwest of Iran.Due to the overcrowding and high patient load,we aim to characterize the rate,cause and consequence of boarding in the ED of this center.Methods All medical records of patients who presented to the ED of Imam Khomeini Hospital from August 1,2017 to August 1,2018 were retrospectively analyzed.Patients with uncompleted records were excluded.Boarding was defined as the inability to transfer the admitted ED patients to a downstream ward in≥2 h after the admission order.Demographic data,boarding rate,mortality and triage levels(1–5)assessed by emergency severity index were collected and analyzed.The first present time of patients was classified into 4 ranges as 0:00–5:59,6:00–11:59,12:00–17:59 and 18:00–23:59.Descriptive,parametric and non-parametric statistical tests were performed and the risk of boarding was determined by Pearson Chi-square test.Results Demographic data analysis showed that 941(58.5%)male and 667(41.5%)female,altogether 1608 patients were included in this study.Five patients(0.3%)died.The distribution of patients with the triage levels 1–5 was respectively 79(4.9%),1150(71.5%),374(23.3%),4(0.2%)and 0(0%).Most patients were of level 2.Only 75(4.7%)patients required intensive care.The majority of patients(84.2%)were presented at weekdays.The maximum patient load was observed between 12:00–17:59.Of the 1608 patients,340(21.1%)experienced boarding within a mean admission time of 13.70 h.Among the 340-boarded patients,20.1%belonged to surgery,12.1%to orthopedics,10.9%to neurosurgery and 10.3%to neurology.The boarding rate was higher in females,patients requiring intensive care and those with low triage levels.Compared with the non-boarded,the boarded patients had a higher mean age.Conclusion The boarding rate is higher in the older and female patients.Moreover,boarding is dependent on the downstream ward sections:patients requiring surgical management experience the maximum boarding rate. | Yousef Nouri Changiz Gholipour Javad Aghazadeh Shahriar Khanahmadi Talayeh Beygzadeh Danial Nouri Mehryar Nahaei Reza Karimi Elnaz Hosseinalipour | 2020 | Chinese Journal of Traumatology2020，23，6： | 1 |
| 3 | Robust Control of Robotic Manipulators in the Task-Space Using an Adaptive Observer Based on Chebyshev Polynomials显示文摘In this paper,an adaptive observer for robust control of robotic manipulators is proposed.The lumped uncertainty is estimated using Chebyshev polynomials.Usually,the uncertainty upper bound is required in designing observer-controller structures.However,obtaining this bound is a challenging task.To solve this problem,many uncertainty estimation techniques have been proposed in the literature based on neuro-fuzzy systems.As an alternative,in this paper,Chebyshev polynomials have been applied to uncertainty estimation due to their simpler structure and less computational load.Based on strictly-positive-rea Lyapunov theory,the stability of the closed-loop system can be verified.The Chebyshev coefficients are tuned based on the adaptation rules obtained in the stability analysis.Also,to compensate the truncation error of the Chebyshev polynomials,a continuous robust control term is designed while in previous related works,usually a discontinuous term is used.An SCARA manipulator actuated by permanent magnet DC motors is used for computer simulations.Simulation results reveal the superiority of the designed method. | GHOLIPOUR Reza FATEH Mohammad Mehdi | 2020 | Journal of Systems Science & Complexity2020，33，5： | 1 |
| 4 | A review of the theory and practice of managing TQM: An integrative framework显示文摘 | Ebrahim Soltani Pei-Chun Lai Sayed Reza Sayed Javadeen Tahmoores Hassan Gholipour | 2008 | Total Quality Management & Business Excellence2008，19，5： | 1 |
| 5 | Severe Acute Respiratory Syndrome Coronavirus 2(SARS-CoV-2)Contamination of High-touch Surfaces in Field Settings显示文摘The World Health Organization declared Coronavirus disease 2019(COVID-19)a public health emergency of international concern(PHEIC)[1].Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the etiological agent of COVID-19,is an enveloped,single-stranded,positive-sense RNA coronavirus.Like severe acute respiratory syndrome coronavirus(SARS)and Middle East respiratory syndrome(MERS),the causative agent of COVID-19belongs to theβ-genus of the coronavirus family and has a genome sequence with an 82%similarity to that of SARS[1,2].Therefore,research on human coronaviruses,especially SARS-CoV and MERS-CoV,could be useful for predicting likely environmental fate and subsequent risks of SARS-CoV-2[1]. | Sahar Gholipour Mahnaz Nikaeen Reza Mohammadi Manesh Shima Aboutalebian Zahra Shamsizadeh Elahe Nasri Hossein Mirhendi | 2020 | Biomedical and Environmental Sciences2020，33，12： | 0 |
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