Production of Hydrogen and Carbon Nanotubes from Methane

Zein, Sharif Hussein Sharif,Mohamed, Abdul Rahman,Sai, P. Sesha Talpa,Zabidi, Noor Asmawati Mohd 한국공업화학회 2004 Journal of Industrial and Engineering Chemistry Vol.10 No.6

The decomposition of methane to produce hydrogen and carbon has been investigated experimentally using 15 ㏖% M/20 ㏖% NiO/TiO₂catalysts (where M = MnO_x, FeO, CoO, and CuO). The physical properties of these catalysts were obtained and their performances were evaluated for the conversion of methane and the CO and hydrogen yields. These catalysts were used in the experiments without any pretreatment. XRD patterns and TEM images of these catalysts show the morphological changes that are due to dopant addition. The results indicate the remarkable influence on the catalytic activity provided by doping. While different types of filamentous carbons are formed on the various Ni-containing catalysts, attractive carbon nanotubes were observed on the Mn/Ni/TiO₂-based catalyst. TEM studies on the used catalyst suggest that its stability depends on growth rate and the morphological structure of the formed carbon.

Lipoxygenase Inhibitory Constituents from Indigofera oblongifolia

Sharif, Ahsan,Ahmed, Ejaz,Malik, Abdul,Riaz, Naheed,Afza, Nighat,Nawaz, Sarfraz Ahmad,Arshad, Muhammad,Shah, Muhammad Raza,Chaudhary, Muhammad Iqbal The Pharmaceutical Society of Korea 2005 Archives of Pharmacal Research Vol.28 No.7

Indigin, alkylated xanthene (1) and indigoferic acid (2) have been isolated from the chloroform soluble fraction of Indigofera oblongifolia, along with $\beta$-sitosterol (3) and 3-hydroxybenzoic acid (4), which are reported for the first time from this species. Their structures were determined through spectroscopic techniques. Both the new compounds 1 and 2 showed significant activity against enzyme lipoxygenase, while 2 further showed moderate inhibition against BChE.

Ubiquitous sensor network simulation and emulation environments: A survey

Sharif, Mohammad,Sadeghi-Niaraki, Abolghasem Academic Press 2017 Journal of network and computer applications Vol.93 No.-

<P><B>Abstract</B></P> <P>Recent human effort has been directed at expanding pervasive smart environments. For this, ubiquitous computing technology is introduced to provide all users with any service, anytime, anywhere, with any device, and under any network. However, high cost, long time consumption, extensive effort, and in some cases irrevocability are the main challenges and difficulties for developing ubiquitous systems. Therefore, one solution is to initially simulate, analyze, and validate practices prior to deploying sensing and computational devices in the real world. Simulation, as a performance evaluation technique, has attracted attentions due to its speed, cost-effectiveness, repeatability, scalability, flexibility, and ease of implementation. Moreover, emulation, as a hybrid method, not only offers most simulation advantages but also benefits from tight control of implementation, as well as a certain degree of realistic results. Both simulators and emulators are significant tools for enhancing the understanding of ubiquitous sensor networks (USNs) through testing and analyzing several scenarios prior to actual sensor placements. In this regard, this paper surveys 130 simulation and emulation environments and frameworks, which were originally designed and adapted for USN. Of these 130, the 22 that have been widely used, regularly updated, and well supported by their developers are compared based on multifarious criteria. Finally, several studies that had favorably compared the performance of simulators and/or emulators are examined. We believe the present research findings will be helpful for students and researchers to pick an appropriate simulator/emulator, and for software developers and those who are keen on producing their own environment.</P>

Functional bowel disorders among bariatric surgery candidates before and after surgery: A prospective cohort study

Sharif Yassin,Noa Sori,Ophir Gilad,Mati Shnell,Relly Richer,Nir Bar,Yishai Ron,Nathaniel Aviv Cohen,Subhi Abu-Abeid,Danit Dayan,Shai Meron Eldar,Shira Zelber-Sagi,Sigal Fishman 소화기인터벤션의학회 2024 International journal of gastrointestinal interven Vol.13 No.1

Background: Functional bowel disorders (FBDs), including irritable bowel syndrome (IBS), are common worldwide. Recently, increasingly many bariatric surgical procedures have been performed in response to rising obesity rates. However, data on the association between FBDs and bariatric surgery are scarce. We examined the prevalence of FBDs among candidates for bariatric surgery and prospectively investigated the association between FBDs and bariatric surgery. Methods: This prospective cohort study included 112 bariatric surgery candidates at the Tel Aviv Medical Center from 2019 to 2020. Before and after surgery, patients completed the Rome III questionnaire. Data regarding demographics, socioeconomic status, and gastrointestinal symptoms were recorded. The rates of FBDs—IBS, functional constipation (FC), functional diarrhea (FDi), and unspecified functional bowel disorder (UFBD)—were then compared from before surgery to 6 months after the procedure. Results: Of 112 candidates with obesity at baseline, 68 underwent surgery and completed the postoperative questionnaire. Overall, the respective prevalence rates of FBDs, IBS, FC, FDi, and UFBD were 37.5%, 2.7%, 17.9%, 5.4%, and 11.6%. Female sex and single status were particularly common among patients with FBDs, whereas divorced status was more frequent in the group without FBDs. However, these factors were not independently associated with FBD presence upon multivariable analysis. IBS was more prevalent after surgery than before (8.8% vs. 1.5%, P = 0.06), but FBDs in general did not share this trend (44.1% vs. 36.8%, P = 0.44). Conclusion: Bariatric surgery appears to increase the risk of developing IBS, while not impacting the overall risk of FBDs.

Wild Mushrooms: A Potential Source of Nutritional and Antioxidant Attributes with Acceptable Toxicity

Sharif, Sumaira,Shahid, Muhammad,Mushtaq, Muhammad,Akram, Sumia,Rashid, Ayoub The Korean Society of Food Science and Nutrition 2017 Preventive Nutrition and Food Science Vol.22 No.2

This paper describes in detail proximate composition, nutritional profile, phytochemical constituents, antioxidant activities, antimicrobial potential, and antihemolytic activity (towards human erythrocytes) of various fractions of wild Ganoderma lucidum. Proximate analysis established that wild G. lucidum comprises about $87.02{\pm}5.45%$ of moisture, and the remaining part is a rich source of proteins ($8.59{\pm}0.37%$), crude fiber ($54.21{\pm}1.2%$), and carbohydrate (35.16%) with smaller fat content (3.33 %). Similarly, phytochemical screening revealed the presence of flavonoids ($217.51{\pm}0.30mg/g$), ascorbic acid ($116{\pm}7.32mg/g$), phenolics ($360.72{\pm}34.07mg/g$), ${\beta}$-carotenes ($0.42{\pm}0.04{\mu}g/g$), and lycopene ($0.05{\pm}0.00{\mu}g/g$). Extracts of wild G. lucidum in various solvents provided first line protection against Escherichia coli and Pasteurella multocida in the order of ethyl acetate> ethanol> methanol> n-hexane> water. Furthermore, aqueous and methanolic extracts of wild G. lucidum were found to be safe towards human erythrocytes. Overall, wild mushroom (G. lucidum) was found to be a good source of dietary supplements, antimicrobial and antioxidant agents in the pursuance of its commercial utilization in food and pharmaceutical industries.

A physically consistent stress-strain model for actively confined concrete

Sharif Shahbeyk,Mahshid Z. Moghaddam,Mohammad Safarnejad 사단법인 한국계산역학회 2017 Computers and Concrete, An International Journal Vol.20 No.1

With a special attention to the different stages of a typical loading path travelled in a fluid confined concrete test, this paper introduces a physically consistent model for the stress-strain curve of actively confined normal-strength concrete in the axial direction. The model comprises of the five elements of: (1) a criterion for the peak or failure strength, (2) an equation for the peak strain, (3) a backbone hydrostatic curve, (4) a transient hardening curve linking the point of departure from the hydrostatic curve to the failure point, and finally (5) a set of formulas for the post-peak region. Alongside, relevant details and shortcomings of existing models will be discussed in each part. Finally, the accuracy and efficiency of the proposed model have been verified in a set of simulations which compare well with the experimental results from the literature.

The investigation of Magnetohydrodynamic nanofluid flow with Arrhenius energy activation

Sharif, Humaira,Khadimallah, Mohamed A.,Naeem, Muhammad Nawaz,Hussain, Muzamal,Mahmoud, S.R.,Al-Basyouni, K.S.,Tounsi, Abdelouahed Techno-Press 2021 Advances in nano research Vol.10 No.5

In this article, an analytically and numerically 3D nanoliquid flow by a porous rotatable disk is presented in the presence of gyrotactic microorganisms. The mathematical model in the form of partial differential system is transmuted into dimensionless form by utilizing the appropriate transformation. The homotopy analysis approach is applied to attain the analytic solution of the problem. The effect of promising parameters on velocity distribution, temperature profile, nanoparticles volume fraction and motile microorganism distribution field are evaluated through graphs and in tabular form. The existence of Brownian motion and thermophoresis impacts are more proficient for heat transfer enhancement. Further the unique features like heat absorption/generation and energy activation are also examined for the present flow problem. The obtained results are compared with the earliear investigation to check the accuracy of present model.

An Open Science 'State of the Art' for Hong Kong: Making Open Research Data Available to Support Hong Kong Innovation Policy

Sharif, Naubahar,Ritter, Waltraut,Davidson, Robert L,Edmunds, Scott C World Association for Triple Helix and Future Stra 2018 Journal of Contemporary Eastern Asia Vol.17 No.2

Open Science is an umbrella term that involves various movements aiming to remove the barriers to sharing any kind of output, resources, methods or tools at any stage of the research process. While the study of open science is relatively advanced in Western countries, we know of no scholarship that attempts to understand open science in Hong Kong. This paper provides a broad-based background on the major research data management organisations, policies and institutions with the intention of laying a foundation for more rigorous future research that quantifies the benefits of open access and open data policies. We explore the status and prospects for open science (open access and open data) in the context of Hong Kong and how open science can contribute to innovation in Hong Kong. Surveying Hong Kong's policies and players, we identify both lost research potential and provide positive examples of Hong Kong's contribution to scientific research. Finally, we offer suggestions regarding what changes can be made to address the gaps we identify.

The Wormhole Routing Attack in Wireless Sensor Networks (WSN)

Sharif, Lukman,Ahmed, Munir Korea Information Processing Society 2010 Journal of information processing systems Vol.6 No.2

Secure routing is vital to the acceptance and use of Wireless Sensor Networks (WSN) for many applications. However, providing secure routing in WSNs is a challenging task due to the inherently constrained capabilities of sensor nodes. Although a wide variety of routing protocols have been proposed for WSNs, most do not take security into account as a main goal. Routing attacks can have devastating effects on WSNs and present a major challenge when designing robust security mechanisms for WSNs. In this paper, we examine some of the most common routing attacks in WSNs. In particular, we focus on the wormhole routing attack in some detail. A variety of countermeasures have been proposed in the literature for such attacks. However, most of these countermeasures suffer from flaws that essentially render them ineffective for use in large scale WSN deployments. Due to the inherent constraints found in WSNs, there is a need for lightweight and robust security mechanisms. The examination of the wormhole routing attack and some of the proposed countermeasures makes it evident that it is extremely difficult to retrofit existing protocols with defenses against routing attacks. It is suggested that one of the ways to approach this rich field of research problems in WSNs could be to carefully design new routing protocols in which attacks such as wormholes can be rendered meaningless.

Decoupling of Arctic variability from the North Pacific in a warmer climate

Sharif Jahfer,Kyung-Ja Ha,Christian L. E. Franzke,Sun-Seon Lee,Keith B. Rodgers,Dong-Eun Lee 한국기상학회 2023 한국기상학회 학술대회 논문집 Vol.2023 No.10