http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
ROBUST DIFFERENTIAL STEERING CONTROL SYSTEM FOR AN INDEPENDENT FOUR WHEEL DRIVE ELECTRIC VEHICLE
Muhammad Arshad Khan,Muhammad Faisal Aftab,Ejaz Ahmed,윤일중 한국자동차공학회 2019 International journal of automotive technology Vol.20 No.1
This research investigates a robust differential steering control system (DSCS) for an independent four wheel drive electric vehicle (EV). The DSCS will maneuver the independently actuated (IA) four wheel drive EV without the help of any conventional steering mechanism (CSM) via the input torque of the four wheels. The differential angular rotation speed between left and right wheels is used to generate the CSM effects. The DSCS is designed using the linear model of the vehicle with linear tire dynamics and is tested in simulations using a nonlinear vehicle model with nonlinear tire dynamics. The proposed DSCS is a combination of forward speed and yaw rate controllers, designed using the robust H∞ control methodology. The effectiveness of the proposed robust controller is analyzed by comparing the performance of the all-wheel drive (AWD), the rear wheel drive (RWD), and the front wheel drive (FWD) vehicles during simulations. The simulations results indicates that the proposed system can successfully maneuver the vehicle under different driving conditions by tracking the desired parameters without the use of any CSM.
Sajid Ullah Butt,Mamoona Arshad,Aamer Ahmed Baqai,Hasan Aftab Saeed,Naveed Akmal Din,Rehan Ahmed Khan 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.5
Fixture design is one of the main factors which affect the final product quality. Proper design of fixture plays an important role in ensuring the required tolerance of the product. Proper placement of locators is one of the prominent factors in fixture design. Locators are elastic: they deform under clamping and machining forces causing rigid body displacement of the workpiece which in turn affects the part quality. In this article, a 3-2-1 type of fixturing system having elastic locators around a considerably rigid rectangular workpiece is considered. A genetic algorithm is proposed, which uses a fitness function that evaluates the positioning error of the workpiece under external forces and torque. Among several variables, 12 variables, which define the placement of locators, are chosen to be optimized while minimizing the positioning error of the workpiece at the point of action of machining force. The proposed algorithm optimizes the 12 interlinked variables, within the specified region, for machining force and torque at a single point. However, when the cutting tool moves to any other point on the workpiece, it is observed that either the workpiece loses its contact with any one of the locators or the positioning error increases by a large value. To overcome this issue, the proposed algorithm is further modified for placement optimization to cater for multi-point machining, and the isostatism of the workpiece is ensured by checking the magnitude and direction of displacement (of what?) at each point of workpiece-locator contact. Finally, the original and modified GA algorithms are explained through a case study where the single point optimized placement shows loss of contact when machining force is applied at other points. The placement optimized from the modified algorithm shows that the isostatism of the workpiece remains intact while all four positioning errors are converged towards the same value. The results obtained from the proposed and modified algorithm are verified using ANSYS simulation.
Maqsood, Muhammad Rizwan,Hanif, Muhammad,Rafiq, Muhammad,Saleem, Muhammad,Zaib, Sumera,Khan, Aftab Ahmed,Iqbal, Mazhar,Iqbal, Jamshed,Rama, Nasim Hasan,Seo, Sung-Yum,Lee, Ki-Hwan Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.12
The target compounds 6-11a-e were synthesized by condensing 4-amino-5-aryl-3H-1,2,4-triazole-3-thiones 5a-f with various aromatic carboxylic acids in the presence of phosphorous oxychloride. The structures of newly synthesized compounds were characterized by IR, $^1H$ NMR, $^{13}C$ NMR, elemental analysis and mass spectrometric studies. All the synthesized compounds were screened for their antibacterial activity. Almost all the tested compounds were potent against four different strains of bacteria when compared with that of reference drug ciprofloxacin. Compounds 6c, 6e, 8d, 9b, 9e, 11a and 11b showed nearly equal or lower MIC values than standard drug, against all four tested bacterial strains but rest of the compounds showed excellent antibacterial activities.
Muhammad Rizwan Maqsood,Muhammad Hanif,Muhammad Rafiq,Muhammad Saleem,Sumera Zaib,Aftab Ahmed Khan,Mazhar Iqbal,Jamshed Iqbal,Nasim Hasan Rama,서승염,Ki-Hwan Lee 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.12
The target compounds 6-11a-e were synthesized by condensing 4-amino-5-aryl-3H-1,2,4-triazole-3-thiones 5a-f with various aromatic carboxylic acids in the presence of phosphorous oxychloride. The structures of newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR, elemental analysis and mass spectrometric studies. All the synthesized compounds were screened for their antibacterial activity. Almost all the tested compounds were potent against four different strains of bacteria when compared with that of reference drug ciprofloxacin. Compounds 6c, 6e, 8d, 9b, 9e, 11a and 11b showed nearly equal or lower MIC values than standard drug, against all four tested bacterial strains but rest of the compounds showed excellent antibacterial activities.
Siyal, Muhammad Irfan,Lee, Chang-Kyu,Park, Chansoo,Khan, Aftab Ahmed,Kim, Jong-Oh Elsevier 2019 Journal of environmental management Vol.243 No.-
<P><B>Abstract</B></P> <P>Investigations on membrane materials for membrane distillation (MD) and its applications have been ongoing since the 1990s. However, a lack of materials that produce robustly stable and up-to-the-mark membranes for MD for different industrial applications remains an ongoing problem. This paper provides an overview of materials developed for MD applications. Although key aspects of published articles reviewed in this paper pertain to MD membranes synthesized for desalination, future MD can also be applied to organic wastewater containing surfactants with inorganic compounds, either with the help of hybrid treatment processes or with customized membrane materials. Many industrial discharges produce effluents at a very high temperature, which is an available driving force for MD. However, there remains a lack of cost-effective membrane materials. Amphiphobic and omniphobic membranes have recently been developed for treating emulsified and shale gas produced water, but the problem of organic fouling and pore wetting remains a major challenge, especially when NaCl and other inorganic impurities are present, which further deteriorate separation performance. Therefore, further advancements in materials are required for the treatment of emulsified industrial wastewater containing surfactants, salts, and for oil or shale gas wastewater for its commercialized reuse. Integrated MD systems, however, may represent a major change in shale gas wastewater and emulsified wastewater that are difficult to treat.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Advancements in materials for membrane distillation </LI> <LI> Coating materials and surface modification technologies </LI> <LI> Shale gas produced water and challenges in wastewater treatment </LI> <LI> Superhydrophobic, Amphiphobic and Omniphobic membranes </LI> <LI> Integrated MD processes with other technologies and advancement needed </LI> </UL> </P>
Rai, Narendra Prakash,Divakar, Darshan Devang,Al Kheraif, Abdulaziz Abdullah,Ramakrishnaiah, Ravikumar,Mustafa, Shabil Mohamed,Durgesh, BH,Basavarajappa, Santhosh,Khan, Aftab Ahmed Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.16
Background: The treatment selection for the oral squamous cell carcinoma remains controversial. Radiation therapy or surgical excision of the lesion can be applied as the sole treatment or it can be used in combination with other treatment modalities. Radiotherapy is considered to be the safest of all the treatment modalities and can be used in several situations for oral and oropharyngeal cancers. The aim of this study was to evaluate the survival outcome differences in patients treated with radical and palliative radiotherapy as the primary treatment modality. Materials and Methods: The study included a total of 47 patients with oral cancer reporting to our hospital between years 2009 to 2010. The age group for the selected patients was more than 65 years, treated with radical and palliative radiotherapy with no prior surgical interventions. Patients were evaluated till Dec 2013 for overall survival time. Results: Twenty nine patients were treated with radical radiotherapy as main stay of treatment, out of which 21 died during the follow up time with median survival of $352{\pm}281.7$ days with 8 patients alive. All the 16 patients were dead who received palliative radiotherapy with a median survival time of $112{\pm}144.0$ days. Conclusions: This retrospective study showed improved overall survival time, loco regional control rates and reduced morbidity in patients treated with radical radiotherapy when compared to patients treated with palliative radiotherapy.