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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Mechanics of Advanced Composite Structures
- نوع مقاله: Journal Article
- کلمات کلیدی: Composite,Cylindrical and Conical Corrugated Tubes,Energy Absorption, Aluminum Foam
- چکیده:
- چکیده انگلیسی: In the present article, a numerical study is performed to investigate the crushing behavior of cylindrical and conical corrugated composite tubes. Different aluminum foams are applied to the proposed structures in order to offer an excellent energy absorption capacity. The crushing behavior of tubes are evaluated in terms of two parameters: SEA (specific energy absorption) and CFE (crush force efficiently). So, in order to study the effect of corrugation on the crashworthiness of composite tubes, a comprehensive numerical analysis of corrugated carbon/BMI tubes is performed under axial loadings. The effect of geometric parameters of corrugation including number and radius of corrugations is studied by FE simulation of several models in LS-DYNA. Comparison between corrugated tubes and straight one demonstrated that the CFE would be improved significantly in these new models. Furthermore, the absorbed energy increased by using foams. SEA, mean force and peak forces increased by increasing the foam density while the crush force efficiently decreased considerably due to the fact that in higher densities, densification region accrues in fewer strains.
- انتشار مقاله: 20-07-1397
- نویسندگان: Mahshid Mahbod,Masoud Asgari
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Ultrafine Grained and Nanostructured Materials
- نوع مقاله: Journal Article
- کلمات کلیدی: corrosion,Nanocomposite,aluminum,Electrolyte,Plasma Electrolytic Oxidation,nickel sulfate
- چکیده:
- چکیده انگلیسی: Plasma electrolytic oxidation (PEO) was performed on a 1010 Aluminum alloy. To achieve the
nanocomposite structure, Si3N4 nanoparticles were added into the electrolyte. In an alkaline aqueous
suspension (silicate-based), the effect of adding NiSO4 on the applied voltage, microstructure,
composition, wear, and corrosion resistance of PEO coatings was investigated using Scanning
Electron Microscopy (SEM), elemental analysis with Energy Dispersive Spectroscopy (EDS), X-Ray
Diffraction (XRD), cyclic polarization test, and pin-on-disk wear test. The results showed that adding
nickel sulfate (NiSO4) and infiltration of its constituents into coatings lead to a more favored corrosion
behavior. Moreover, in the case of best sample, anodic current at the highest applied potential
condition during the cyclic polarization test indicated a drop within two decades. Moreover,
coefficient of friction decreased almost by half.- انتشار مقاله: 10-05-1394
- نویسندگان: Ali Abolhasani,Mahmood Aliofkhazraei,Seyed Saeed Farhadi,Alireza Sabour Rouhaghdam,Masoud Asgari
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Dermatology
- نوع مقاله: Journal Article
- کلمات کلیدی: Papanicolaou Smear,Pemphigus vulgaris,Genital,Cervix
- چکیده:
- چکیده انگلیسی: Background and aim: Pemphigus vulgaris (PV) is an autoimmune blistering disease which is known to involve the female genital tract but the frequency at which this occurs is unknown. There are relatively few reports in the literature of the cytological appearance of PV on cervicovaginal smears. Our aim was to evaluate involvement of the female genital tract and cervicovaginal Papanicolaou (Pap) smears in PV.
Materials and methods: The study included 77 patients with PV visited from April 2005 to February 2007. Each patient was subjected to gynecological examination and cervicovaginal Pap smear.
Results: The mean age of patients was 44.7±13 years. Genital lesions were observed in 39 patients (50.6%). Labia minor was involved in 36 patients (92.3%), while labia major in 11 (28.2%), vagina in 14 (35.8%), and cervix in six (15.3%). Cervicovaginal smears of 20 patients (25.9%) showed PV. Among 72 satisfactory smears, cervical Pap smears were normal in 25 patients (34.7%), inflammatory in 43 patients (59.7%), and dysplastic (low-grade cervical intra-epithelial neoplasia [CIN I]) in four patients (5.5%). In 2 of these patients, Pap smears was normal repeated when patients were in remission.
Conclusion: Involvement of the female genital tract might not be as infrequent as was previously thought and it is probably the second most common mucosal site of PV after oral mucosa. Genital lesions may be missed and the need for thorough pelvic examination should not be overlooked.- انتشار مقاله: 11-10-1348
- نویسندگان: Maryam Akhyani,Cheyda Chams-Davatchi,Zahra Safai Naraghi,Maryam Daneshpazhooh,Siavash Toosi,Masoud Asgari,Fatemeh Malek Hami
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Foreign Language Teaching & Research
- نوع مقاله: Journal Article
- کلمات کلیدی: Vocabulary Learning,attitude,Computer-assisted language learning,Web-quest
- چکیده:
- چکیده انگلیسی: Web-quests are internet-based technology applications in which groups of students follow a specific set of steps toward the completion of a final project on a specific subject or a multi-disciplinary subject. The present study aimed to investigate the impacts of using web-quests on learning vocabulary by Iranian pre-university students. The sample of the study consisted of 72 students assigned into two groups. One of the groups represented the control group, and included 23 students; the other group represented the experimental group and comprised 49 students. The two groups were chosen from a population of pre-university students in Chadegan, Isfahan, Iran. The web-quest strategy was used in teaching the experimental group, while the traditional method was used with the control group in the second term of the school year 2015-2016. An Oxford Placement Test (OPT), a vocabulary pretest, a vocabulary posttest, and an attitude questionnaire were the data elicitation tools employed in this study. The collected data were analyzed using independent-samples t test, which was used to determine the existence of possible significant differences between the groups both before and after the instruction. The results indicated that there were statistically significant differences between both groups in favor of the experimental group. The conclusion, thus, could be that the students in the experimental group, who used the web-quest resources for learning vocabulary, performed significantly better than the students in the control group, who learnt vocabulary through traditional method of learning vocabulary. Finally, questionnaire data analyzed via one-sample t test indicated that the experimental group learners had a positive attitude towards the treatment they experienced in the experiment.
- انتشار مقاله: 23-11-1396
- نویسندگان: Masoud Asgari,Hadi Salehi
- مشاهده