Numerical evaluation of the effect of multiple roughness changes

Abdi, Daniel S.,Bitsuamlak, Girma T. Techno-Press 2014 Wind and Structures, An International Journal (WAS Vol.19 No.6

The effect of multiple roughness changes close to a building site was examined through three dimensional computational fluid dynamics (CFD) simulations conducted in a virtual boundary layer wind tunnel (V-BLWT). The results obtained were compared with existing wind speed models, namely ESDU-82026 and Wang and Stathopoulos (WS) model. The latter was verified by wind tunnel tests of sixty nine cases of multiple roughness patches, and also with a simplified 2D numerical model. This work extends that numerical study to three dimensions and also models roughness elements explicitly. The current numerical study shows better agreement with the WS model, that has shown better agreements with BLWT tests, than the ESDU model. This is in contrast to previous results of Wang and Stathopoulos, who concluded that CFD shows better agreement with the ESDU model. Many cases were simulated in a V-BLWT that has same dimensions as BLWT used in the original experiment and also in a reduced symmetrical version (S-BLWT) that takes advantage of regular arrangement of roughness blocks. The S-BLWT gives results almost identical to V-BLWT simulations, while achieving significant reduction on computational time and resources.

Rapid Micropropagation through Shoot Regeneration of Valeriana officinalis L.

Abdi Gholam Reza,Khosh-Khui Morteza,Shekafandeh Akhtar 한국원예학회 2009 Horticulture, Environment, and Biotechnology Vol.50 No.5

Simplified Design and Optimization of Slotless Brushless DC Machine for Micro-Satellites Electro-Mechanical Batteries

Abdi, Babak,Bahrami, Hamid,Mirtalaei, S.M.M. The Korean Institute of Electrical Engineers 2013 Journal of Electrical Engineering & Technology Vol.8 No.1

Electro-Mechanical Batteries have important advantages compared with chemical batteries, especially in Low Earth Orbit satellites applications. High speed, slotless, external rotor, brushless DC machines are proposed and used in these systems as Motor/Generator. A simplified analytic design method is given for this type of machines and, the optimization of machine in order to have maximum efficiency and minimum volume and weight are given in this paper. Particle swarm optimization (PSO) is used as the optimization algorithm and the finite element-based simulations are used to confirm the design and optimization process and show less than 6% error in parametric design.

Simultaneous HPLC Analysis of Three Flavonoids in the Extracts of Artocarpus heterophyllus Heartwoods

Abdi Wira Septama,Pharkphoom Panichayupakaranant 한국생약학회 2016 Natural Product Sciences Vol.22 No.2

A reversed-phase high-performance liquid chromatographic method is described for the simultaneous determination of three antibacterial flavonoids, artocarpanone, artocarpin, and cycloartocarpin in ethyl acetate extracts from Artocarpus heterophyllus heartwoods. Separation was achieved using a TSK-gel ODS-80Tm column (5 μm, 4.6 × 150 mm) at 25 ℃ with a gradient elution system of methanol and water as follows: 0-8 min, 60:40; 8-27 min, 80:20; 27-35 min, 60:40, v/v, at a flow rate of 1 mL/min, and a quantitative UV detection at 285 nm. The method was validated by measuring the key parameters, including specificity, linearity, sensitivity, accuracy, repeatability and reproducibility. A high degree of specificity and sensitivity was achieved. The calibration curves for all three flavonoids showed good linearity with a coefficient of determinations (R2) of ≥ 0.9995. The recoveries of the method were from 98-104%, with good reproducibility and repeatability (RSD values of less than 2%) were also achieved. Ethyl acetate was the best solvent for extraction of these three flavonoids using the heat reflux conditions for 1 h. This optimized sample preparation and HPLC method can be practically used for a routine standardization process of the extracts from the A. heterophyllus heartwoods.

A bidirectional neural interface CMOS analog front-end IC with embedded isolation switch for implantable devices

Abdi, Alfian,Cha, Hyouk-Kyu Elsevier Ltd 2016 Microelectronics Journal Vol.58 No.-

<P>A bidirectional neural interface analog front-end IC with both stimulation and recording functions is implemented using 0.18-mu m standard CMOS process. The proposed IC is comprised of a bipolar biphasic neural stimulator using a transistor-stacked current- mirror driver to achieve good current matching performance in stimulation mode and low-voltage capacitive feedback neural amplifiers for recording mode. In order to save die area, high-voltage isolation switches are embedded within the stimulator core to protect the low-voltage recording circuits from damage. Despite using a low-voltage process, the stimulator is able to deliver up to 1 mA current through 10 k ohm load using 12.8 V supply voltage and the recording amplifier uses 0.8 V supply voltage while consuming 1 mu A of current. The complete IC occupies 0.29 mm(2) of die area and can be applied for various multi electrode array interface bidirectional neural SoCs in medical implant devices.</P>

Helicobacter pylori babA2 Positivity Predicts Risk of Gastric Cancer in Ardabil, a Very High-Risk Area in Iran

Abdi, Esmat,Latifi-Navid, Saeid,Yazdanbod, Abbas,Zahri, Saber Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.2

Background: Ardabil, a Northwestern province of Iran, was found to have the highest rate of gastric cancer (GC) in the country (ASRs = 51.8/100,000 for males and 24.9/100,000 for females) and one of the highest gastric cardia cancer rates in the world. The aim of the present study was to assess the associations of the cagA and babA2 status of Helicobacter pylori with GC in the Ardabil population. Materials and Methods: A total of 103 patients with non-atrophic gastritis (56) and GC (47), who underwent endoscopy at the Imam Khomeini Hospital in Ardabil, were assessed. The status of 16S rDNA, cagA and babA2 genes was determined using PCR and histopathological assessment was performed. Results: The following genotypic frequency was observed: cagA+ (50.6%), cagA-(49.4%), babA2+ (26.5%), babA2- (73.5%) cagA+/babA2+ (19.3%), cagA-/babA2+ (7.2%), cagA+/babA2-(31.3%), cagA-/babA2-(42.2%). Although the frequency of the cagA+, cagA+/babA2+ and cagA-/babA2+ genotypes in patients with GC (55.6%, 25.9%, and 14.8%, respectively) was higher than in those with NAG (48.2%, 16.1%, and 3.6%, respectively), the difference did not reach significance. In contrast, the presence of the babA2 gene (40.7% vs 19.6%) significantly increased the risk of GC; the age-sex-adjusted odds ratio (95% confidence interval) was 5.068 (1.506-17.058; P=0.009), by multiple logistic regression. Conclusions: It is proposed that the H. pylori babA2 positivity might be considered as an important determinant of GC risk in Ardabil.

Insertion/Deletion Polymorphism of the Angiotensin ConvertingEnzyme Gene in Coronary Artery Disease in Southern Turkey

Abdi Bozkurt,Gulsah Seydaoglu,Esmeray Acart?k,G?en Attila,Onur Akplnar,Sel?k Matyar 한국생화학분자생물학회 2005 BMB Reports Vol.38 No.4

Nano Bowls of Carbon by Oxidative Chopping of Carbon Nano Sphere

Abdi, Sayed Hasan Razi,Kim, Young Jin,Park, Yong-Ki,Lee, Chul Wee Chemical Society of Japan 2007 Chemistry letters Vol.36 No.10

<P>Here, we report the preparation of novel carbon material having fairly uniform bowl shape in nanosize domain with varying oxygen content by a very simple oxidative chopping of carbon nanoballs, where we have effectively functionalized the inert CNS (carbon nano sphere) with carboxylate groups that can be utilized for the chemical immobilization of enzymes, bioactive compounds, and catalysts.</P>

Technical-Economical Evaluation of Chain Vertical Alignment in Underground Urban Subways: The Case of Qom Subway, Line A

Abdi Kordani, Ali,Mehrara Molan, Amirarsalan The Korean Society for Railway 2014 International Journal of Railway Vol.7 No.2

Urban subways are one of the main parts of urban transportation networks in every city that always requires much attention in order to improve its efficiency in aspects of safety, reliability speed and costs. As the viewpoint of costs, an accurate design, especially design of vertical alignment, can have a dominant role to reduce the costs of urban railway projects. This paper seeks to evaluate the advantages and disadvantages of designing chain vertical alignment for urban subways in compare to flat vertical alignment. To achieve this goal, line A of Qom subway in Iran was selected as a case study in this research. Five parameters considered in the technical-economical evaluation: (1) energy consumption, (2) rolling stock, (3) operation, (4) civil works and geotechnical and (5) hydrological, drainage and pumping. According to the results, a power saving of about 40% have been estimated in the chain vertical alignment for the train without regenerative braking in compare with the flat vertical alignment, although the power saving was calculated less than 10% for the train with regenerative braking. Finally it was found that due to the modern rolling stock technology, the chain vertical alignment represents fewer advantages in compare to the past years.

Identifying the conceivable diplomatic outcomes of Sport Diplomacy initiatives

Abdi Kambiz,Fullerton Jami,Deheshti Mohammad,Kavand Reza,Monibi Hamidreza,Talebpour Mahdi 한국외국어대학교 국제지역연구센터 2022 International Area Studies Review Vol.25 No.4

Although studies around Sport Diplomacy (SD) are expanding rapidly, there is no specific agreement on the outcomes of SD initiatives. The purpose of this study is to identify the conceivable diplomatic outcomes of SD from the perspective of international public diplomacy and sport experts. Researchers used a fuzzy Delphi method, which is an advanced version of the qualitative Delphi method that employs statistics to determine the distance between the levels of consensus within the expert panel. Thirty online surveys were completed by the experts, who were selected through targeted sampling. The statistical population included public diplomacy and sports scholars, and the researchers identified about 200 individuals who qualified for the sampling population because of their academic studies in the fields of public, cultural, and sport diplomacy. After running two rounds of fuzzy Delphi, the SD outcomes were classified into two categories of explicit/specific outcomes and implicit/general outcomes. The results showed that the outcomes of “cross-cultural communication,” “mutual understanding,” “trust building,” “nation branding,” “country reputation,” “attraction,” and “co-option” were the most possible explicit/specific outcomes of SD initiatives undertaken by countries’ ministries of foreign affairs and related agencies. “Sport industry development,” “sport tourism development,” and “socio-economic development” were the most possible outcomes of the implicit/general efforts of SD initiatives undertaken by the sport federations, private sector, NGOs, and other institutions outside the formal diplomacy system. Co-option-A term derived from Nye's theory of soft power as the ultimate goal/outcome of SD endeavors is manifested in “Peace Building (Conflict Conciliation)” between hostile states/nations and “Peace Development” between friendly states/nations.