Numerical study of airfoil thickness effects on the performance of J-shaped straight blade vertical axis wind turbine

Zamani, Mahdi,Maghrebi, Mohammad Javad,Moshizi, Sajad A. Techno-Press 2016 Wind and Structures, An International Journal (WAS Vol.22 No.5

Providing high starting torque and efficiency simultaneously is a significant challenge for vertical axis wind turbines (VAWTs). In this paper, a new approach is studied in order to modify VAWTs performance and cogging torque. In this approach, J-shaped profiles are exploited in the structure of blades by means of eliminating the pressure side of airfoil from the maximum thickness toward the trailing edge. This new profile is a new type of VAWT airfoil using the lift and drag forces, thereby yielding a better performance at low TSRs. To simulate the fluid flow of the VAWT along with J-shaped profiles originated from NACA0018 and NACA0030, a two-dimensional computational analysis is conducted. The Reynolds Averaged Navier-Stokes (RANS) equations are closed using the two-equation Shear Stress Transport (SST) turbulence model. The main objective of the study is to investigate the effects of J-shaped straight blade thickness on the performance characteristics of VAWT. The results obtained indicate that opting for the higher thickness in J-shaped profiles for the blade sections leads the performance and cogging torque of VAWT to enhance dramatically.

Numerical study of airfoil thickness effects on the performance of J-shaped straight blade vertical axis wind turbine

Mahdi Zamani,Mohammad Javad Maghrebi,Sajad A. Moshizi 한국풍공학회 2016 Wind and Structures, An International Journal (WAS Vol.22 No.5

Providing high starting torque and efficiency simultaneously is a significant challenge for vertical axis wind turbines (VAWTs). In this paper, a new approach is studied in order to modify VAWTs performance and cogging torque. In this approach, J-shaped profiles are exploited in the structure of blades by means of eliminating the pressure side of airfoil from the maximum thickness toward the trailing edge. This new profile is a new type of VAWT airfoil using the lift and drag forces, thereby yielding a better performance at low TSRs. To simulate the fluid flow of the VAWT along with J-shaped profiles originated from NACA0018 and NACA0030, a two-dimensional computational analysis is conducted. The Reynolds Averaged Navier-Stokes (RANS) equations are closed using the two-equation Shear Stress Transport (SST) turbulence model. The main objective of the study is to investigate the effects of J-shaped straight blade thickness on the performance characteristics of VAWT. The results obtained indicate that opting for the higher thickness in J-shaped profiles for the blade sections leads the performance and cogging torque of VAWT to enhance dramatically.

Moderate Exercise Enhances the Production of Interferon-γ and Interleukin-12 in Peripheral Blood Mononuclear Cells

Alireza Zamani,Iraj Salehi,Mahdi Alahgholi-Hajibehzad 대한면역학회 2017 Immune Network Vol.17 No.3

The purpose of this study was to explore the effect of two months moderate exercise on levels of IFN-g, IL-12, IL-6 and IL-4 in serum and supernatants of in vitro mitogen-activated (PHA for 48 h) whole blood (WB) and peripheral blood mononuclear cells (PBMCs). Sixteen healthy males participated in running program (30 min/day, 5 days/ week). Blood samples were collected in three stages; 24 h before to start exercise, 48 h and two months after the last session of the exercise. The samples were analyzed for the cytokines by ELISA. The levels of IFN-g and IL-12 were increased significantly in activated PBMCs culture after exercise and were back to normal level after two months rest. A significant elevation of IFN-g/IL-4 ratio was observed in activated PBMCs culture by acting possibly on IFN-g. The results suggest that short moderate intensity exercise enhances Th1 immune inflammatory and anti-allergic conditions in response to mitogen.

Dynamics and Stable Gait Planning of a Quadruped Robot

Ali Zamani,Mahdi Khorram,S. Ali A. Moosavian 제어로봇시스템학회 2011 제어로봇시스템학회 국제학술대회 논문집 Vol.2011 No.10

In this paper, dynamics and gait planning of a quadruped robot is discussed. To this end, using Lagrangian method the equations of motion are first derived. Then, an approach is proposed to eliminate the terms corresponding to the constraints caused by the feet on the ground. The obtained dynamics model is validated using Matlab SimMechanics. Finally, gait planning of the robot is developed such that the robot can walk with a given speed over a flat terrain while the robot center of mass remains inside the support polygon. Obtained results reveal stable walking of a quadruped robot based on the proposed approach.

A hybrid controller based on CPG and ZMP for biped locomotion

Amir Massah B.,Ali Zamani,Yaser Salehinia,Mahdi Aliyari Sh.,Mohammad Teshnehlab 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.11

Biped locomotion has attracted much attention in recent years. The most successful implemented methods in this area are based on two approaches, central pattern generator (CPG) and zero moment point (ZMP). Unfortunately, neither of these concepts can solely solve the movement challenge completely. In this study, we introduce a hybrid controller to combine the advantages of these methods. The proposed controller is based on two major approaches, CPG and ZMP. This hybrid controller is composed of a trajectory control system and a trajectory generator system. The trajectory control system applied to keep the robot stable uses ZMP as a real time control feedback. The trajectory generator system, which is composed of nonlinear oscillators, generates stable motions. The parameters of CPG are tuned by a new two-stage approach using differential evolution (DE) and bees algorithm (BA). Furthermore, performance of the proposed controller is verified using the robotic simulation software Webots.

Decreased Levels of Spleen Tissue CD4+CD25+Foxp3+ Regulatory T Lymphocytes in Mice Exposed to Berberine

Gholamreza Karimi,Mahmoud Mahmoudi,Mahdi Balali-Mood,Maryam Rahnama,Shahrzad Zamani Taghizadeh Rabe,Nafiseh Tabasi,Bamdad Riahi-Zanjani 사단법인약침학회 2017 Journal of Acupuncture & Meridian Studies Vol.10 No.2

The effects of isoquinoline alkaloid berberine (BER) on spleen tissue CD4þCD25þFoxp3þ regulatory T (Treg) cells were evaluated in BALB/c mice. Here, BER was administered daily by intraperitoneal injection at doses of 5 mg/kg and 10 mg/kg for 14 days. Following the exposure, mice spleen cellularities, IL-10 production by splenocytes, and spleen Treg/CD4þ cell profiles were studied in all the test groups of animals. The results showed that a high dose of BER (10 mg/kg) could decrease both the absolute and relative percentages of spleen Treg cells as well as decrease the production of IL-10 by splenocytes in the treated mice (p < 0.05). BER at 5 mg/kg did not appear to affect any of these parameters. Based on the finding here, it would seem that BER has effective immunostimulatory properties, which contradicts the results from other studies indicating immunosuppressive effects of BER. Depending on the doses of BER used, it might have a broad spectrum from immunosuppressive to stimulatory effects. Further studies, including more doses, are required to better evaluate the effects of this natural product. Mechanistic studies are required, particularly in case of redox state of the immune cells, to elucidate and determine how BER functions to impart the toxicity effects demonstrated here and in other studies.

Numerical study of vortex shedding in viscoelastic flow past an unconfined square cylinder

Mahmood Norouzi,Seyed Rasoul Varedi,Mahdi Zamani 한국유변학회 2015 Korea-Australia rheology journal Vol.27 No.3

In this paper, the periodic viscoelastic shedding flow of Giesekus fluid past an unconfined square cylinder is investigated numerically for the first time. The global quantities such as lift coefficient, Strouhal number and the detailed kinetic and kinematic variables like normal stress differences and streamlines have been obtained in order to investigate the flow pattern of viscoelastic flow. The effects of Reynolds number and polymer concentrations have been clarified in the periodic viscoelastic flow regime. Our particular interest is the effect of mobility parameter on the stability of two dimensional viscoelastic flows past an unconfined square cylinder. To fulfill this aim, the mobility parameter has been increased from 0 to 0.5 for different polymer concentrations. Results reveal that mobility factor noticeably affects the amplitude of lift coefficient and shedding frequency more strongly at higher polymer concentrations

Sensitive High-Resolution Melting Analysis for Screening of KRAS and BRAF Mutations in Iranian Human Metastatic Colorectal Cancers

Niya, Mohammad Hadi Karbalaie,Basi, Ali,Koochak, Aghigh,Tameshkel, Fahimeh Safarnezhad,Rakhshani, Nasser,Zamani, Farhad,Imanzade, Farid,Rezvani, Hamid,Adib sereshki, Mohammad Mahdi,Sohrabi, Masoud Rez Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.12

Background: Investigations of methods for detection of mutations have uncovered major weaknesses of direct sequencing and pyrosequencing, with their high costs and low sensitivity in screening for both known and unknown mutations. High resolution melting (HRM) analysis is an alternative tool for the rapid detection of mutations. Here we describe the accuracy of HRM in screening for KRAS and BRAF mutations in metastatic colorectal cancer (mCRCs) samples. Materials and Methods: A total of 1000 mCRC patients in Mehr Hospital, Tehran, Iran, from Feb 2008 to May 2012 were examined for KRAS mutations and 242 of them were selected for further assessment of BRAF mutations by HRM analysis. In order to calculate the sensitivity and specificity, HRM results were checked by pyrosequencing as the golden standard and Dxs Therascreen as a further method. Results: In the total of 1,000 participants, there were 664 (66.4%) with wild type and 336 (33.6%) with mutant codons 12 and/or 13 of the KRAS gene. Among 242 samples randomly checked for the BRAF gene, all were wild type by HRM. Pyrosequencing and Dxs Therascreen results were in line with those of the HRM. In this regard, the sensitivity and specificity of HRM were evaluated as 100%. Conclusion: The findings suggest that the HRM, in comparison with DNA sequencing, is a more appropriate method for precise scanning of KRAS and BRAF mutations. It is also possible to state that HRM may be an attractive technique for the detection of known or unknown somatic mutations in other genes.