http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Mansour Razavi (검색결과 2 건)
- 무료
- 기관 내 무료
- 유료
-
Synthesize of V4AlC3 Based MAX Phase Composites by Reactive Spark Plasma Sintering of V2O5:Al:C
Leila Sadeghi,Mansour Razavi,Mohammad Mahdi Kalantarian,Mohammad Reza Rahimipour,Mohsen Hossein‑Zadeh 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.12
In this research V4AlC3based composites were synthesized by reactive spark plasma sintering (RSPS) method. V2O5:Al:Cstarting materials with molar ratios of 1:6:1.5 and 1:7:1.5 were heat treated at 1400 °C. Final composition, microstructural,physical, mechanical and tribological properties of the prepared composites were compared. The X-ray diffraction analysisresults showed that the formation of V4AlC3as main phase alongside Al2O3and V2AlCby-products. Increasing the Al contentfrom 6 moles to 7 moles led to formation of VC0.845and Al2O3main phases as well as V4AlC3and V2AlCminor phases in thissample due to extraction of Al from die during RSPS operation. Microstructural studies revealed that the uniform distributionof the phases with low amount of porosities. The layered microstructure of the composites confirmed the formation ofMAX phases. Higher bending strength and is achieved for the synthesized composite prepared by 7 moles Al (490 ± 5 MPa)than the composite prepared with 6 moles Al (375 ± 11 MPa). The composite prepared with 7 moles Al also exhibited lowerwear rate (3.7 × 10− 5 mm3/Nm) than that of prepared with 6 moles Al (2.4 × 10− 4 mm3/Nm). Microstructural studies of theworn surfaces indicated that tribo oxidation is dominant mechanism for both fabricated composites.
-
Nasim Shams,Mahshid Razavi,Mansour Zabihzadeh,Mohammadreza Shokuhifar,Vahid Rakhshan 대한악안면성형재건외과학회 2022 Maxillofacial Plastic Reconstructive Surgery Vol.44 No.-
Background: Nasal septum deviation (NSD) can cause serious anatomical and clinical complications. It can changethe breathing pattern and thus alter the anatomy of the airway structures. Despite its importance, the associationbetween NSD with the nasopharynx volume (NPV) has not been assessed before. Therefore, we aimed to investigateit for the first time. Methods: Archival CBCTs of 202 patients older than 17 years and without any history of trauma or pathology of thenasopharynx and without any orthodontic/orthognathic treatments were evaluated (129 women, 73 men, meanage: 36.24 ± 14.61 years). All included CBCTs must have been taken with a 12 × 8 field of view and fully covered thenasopharynx areas. The extent of NSD (°) and NPV (mm3) were measured. NSDs were categorized as mild (NSD ? 9°),moderate (9 ≤ NSD ≤ 15°), and severe (NSD ? 15°). Associations between sex, age, NSD, and nasopharynx volumewere assessed using independent-samples t test, chi-square, one-way ANOVA, Tamhane post hoc test, Pearson andpoint-biserial correlation coefficients, and multiple linear regressions (α = 0.05). Results: Mean NSDs were 11.27 ± 4.69° (range 1?19.5), 11.58 ± 4.63°, and 10.70 ± 4.76° in the sample, females, andmales, respectively (P > 0.05). Of females, 27.9%, 40.3%, and 31.8% had mild, moderate, and severe NSDs. These were35.6%, 39.7%, and 24.7% in males (P > 0.05). Mean NPVs were 4.88 ± 1.49, 4.80 ± 1.43, and 5.04 ± 1.60 mm3in thesample, females, and males, respectively (P > 0.05). Mean NPVs were 6.41 ± 1.21, 4.87 ± 0.73, and 3.30 ± 0.65 mm3inmild, moderate, and severe NSD groups (all P values = 0.000). Mean ages were 27.06 ± 6.49, 29.80 ± 9.64, and 54.73± 8.45 years in mild, moderate, and severe NSD groups (severe group being older than the other two groups, P =0.000). NSD was strongly, negatively correlated with NPV (R = ? 0.793, P = 0.000). Sex was not correlated with NPV orNSD (P ≥ 0.189). Age was negatively and positively correlated with NPV and NSD, respectively (P = 0.000). ModelingNSD (β = ?0.776, P = 0.000) as a predictor for NPV rendered age effect insignificant (P > 0.05). Conclusions: It was found, for the first time, that the more deviated the nasal septum, the smaller the nasopharynxvolume. Aging might increase NSD and through it, reduce the nasopharynx volume. Sex might not affect NSD or NPV.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
