http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
The Synthesis Process of New 2D Material MXene: Manganese Carbide Mn2C
Ngoc Bao Tran,강영종 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.1
MXenes (two-dimensional transition metal carbide, carbonitrides and nitrides) was first discovered in 2011, there are several compositions belong to this new 2D group that has been synthesized. In recent years, the publications about MXenes were more and more increasing due to their properties such as high electrical conductivity, functional terminal surface, which can be applied in immersion application (the most well-known is energy storage, and water purification, electromagnetic interference shielding) as well as their unknown theoretically (can be known is the randomly of their terminal surface arrangement). From MAX phase, the etching process can remove the metal layers (like Aluminum or Gallium) to obtain the MXene structure. Our research stays focus to use the MXene of Manganese metal, we first use Mn2AlC as the precursor and synthesis Mn2CTx, then we will study their characterization and their application.
Numerical Analysis on the Cavitation Performance of a Seawater Cooling Pump
Bao Ngoc Tran,김준호 해양환경안전학회 2019 海洋環境安全學會誌 Vol.25 No.1
In this study, a centrifugal seawater cooling pump was analyzed to investigate its cavitation behavior over different operating flow rates. 3D two-phase simulations were carried out with ANSYS-CFX commercial code. The k-ε turbulence and Rayleigh-Plesset cavitation models were employed in the simulations. A head drop characteristics curves for three discharge rates was built based on numerical predictions. At higher flow rates, the impeller was more vulnerable to bubble cavitation. The 3% head drop points of the pump working at 0.7Q, Q, and 1.3Q (Q: design flow rate) corresponded with NPSHa 1.21m, 1.83m, and 3.45m, respectively. The volume of vapor bubbles was estimated and cavitation locations were anticipated to visualize the development of the cavity within the impeller. Moreover, the distribution of pressure coefficient and a blade loading chart are specifically presented, bringing out the harmful impacts of cavitation on the pump operation.
Internal Flow Analysis of Seawater Cooling Pump using CFD
Ngoc Tran Bao,Chang-jo Yang,Bu-gi Kim,Jun-ho Kim 해양환경안전학회 2017 해양환경안전학회지 Vol.23 No.1
본 연구는 원심펌프 내부 유동장 특성에 대한 시뮬레이션 및 시각화에 중점을 둔다. 3D 수치해석은 Reynolds Average Navier-stock 코드를 k-Ɛ 표준 2차방정식 난류 모델로 처리하여 수행하였다. 시뮬레이션은 흡입측, 임펠러, 토출측 영역에서 조도로 인한 마찰 손실과 임펠러 웨어링에서 체적 손실을 포함한다. 해석과 실험사이의 성능곡선 비교결과 최대 5 %의 작은 차이를 보이며 동일한 추세를 나타냈다. 최고 효율점에서 속도 벡터는 고르게 나타났지만 비 설계점에서는 현저한 변화가 나타났고, 텅 부근의 임펠러 유로토출부에서 강력한 재순환 영역이 나타났다. 비교적 일정한 압력분포가 텅 부근임에도 불구하고 임펠러 주위에 관찰되었다. 볼류트 내에서 기하학적으로 인해 형성된 나선형 와류가 이 영역에서 유동장이 상대적으로 난류이고 불안정하다는 것을 증명하였다. This research focuses on simulation and visualization of flow field characteristics inside a centrifugal pump. The 3D numerical analysis was carried out by using a numerical CFD tool, addressing a Reynolds Average Navier-Stock code with a standard k-Ɛ two-equation turbulence model. The simulation accounts for friction head loss due to rough walls at suction, impeller, discharge areas and volumetric head loss at impeller wear ring. A comparison of performance curves between simulation and experimentation is included, and it reveals a same trend of those results with a small difference of maximum 5 %. At best efficiency point, velocity vectors are smooth but it changes significantly under off-design point, a strong recirculation appears at the outlet of impeller passages near tongue area. A relatively uniform preassure distribution was observed around the impeller in despite of the tongue. Within the volute, because of its geometry, spiral vortexes formed, proving that the flow field in this region was relatively turbulent and unsteady.
Bao Ngoc Tran,Hanh Thuy Nguyen,김종오,용철순,Chien Ngoc Nguyen 대한약학회 2017 Archives of Pharmacal Research Vol.40 No.12
The CD44 receptor, which is upregulated inmany cancer cells, provides a selective cellular surface fortargeted drug delivery systems. We developed a hybridnanocarrier for the CD44-targeted delivery of ibuprofen(IBU) and paclitaxel (PTX). The solid lipid nanoparticles(SLNs) were prepared by a hot-melt oil/water emulsiontechnique and then coated with hyaluronic acid (HA) byelectrostatic interactions. The final SLN were sphericalwith a hydrodynamic diameter (Z) of 72.16 ± 2.9 nm,polydispersity index (PDI) of 0.276 ± 0.009, and zetapotential (ZP) of 28.20 ± 0.69 mV. Similarly, SLN coatedwith HA (SLN-HA) exhibited acceptable physical properties(Z 169.3 ± 0.55 nm, PDI 0.285 ± 0.004, and ZP- 10.5 ± 0.15 mV). Cell viability assays showed that thecombination of IBU, a chemopreventive agent, and PTXexerted a synergistic inhibitory effect on the proliferationof cancer cells (CI\1.0). Additionally, our observationsindicated that both SLN and SLN-HA enhanced apoptosisand cellular uptake compared to the cocktail of free drugs. HA indicated its affinity for cancer cells through theimprovement of cellular uptake and induction of apoptosis. These results clearly indicated that these nanoparticlesystems hold great promise for drug delivery in breastcancer treatment.
Bao Ngoc N. Tran,Austin D. Chen,Melisa D. Granoff,Anna Rose Johnson,Parisa Kamali,Dhruv Singhal,Bernard T. Lee,Eugene Y. Fukudome 대한성형외과학회 2019 Archives of Plastic Surgery Vol.46 No.4
Background Sternal rigid plate fixation (RPF) has been adopted in recent years in high-risk cases to reduce complications associated with steel wire cerclage, the traditional approach to sternal closure. While sternal RPF has been associated with lower complication rates than wire cerclage, it has its own complication profile that requires evaluation, necessitating a critical examination from a national perspective. This study will report the outcomes and associated risk factors of sternal RPF using a national database. Methods Patients undergoing sternal RPF from 2005 to 2016 in the American College of Surgeons-National Surgical Quality Improvement Program were identified. Demographics, perioperative information, and complication rates were reviewed. Logistic regression analysis was performed to identify risk factors for postoperative complications. Results There were 381 patient cases of RPF identified. The most common complications included bleeding (28.9%), mechanical ventilation >48 hours (16.5%), and reoperation/readmission (15.2%). Top risk factors for complications included dyspnea (odds ratio [OR], 2.672; P<0.001), nonelective procedure (OR, 2.164; P=0.010), congestive heart failure (OR, 2.152; P=0.048), open wound (OR, 1.977; P=0.024), and operating time (OR, 1.005; P<0.001). Conclusions Sternal RPF is associated with increased rates of three primary complications: blood loss requiring transfusion, ventilation >48 hours, and reoperation/readmission, each of which affected over 15% of the study population. Smokers remain at an increased risk for surgical site infection and sternal dehiscence despite RPF’s purported benefit to minimize these outcomes. Complications of primary versus delayed sternal RPF are roughly equivalent, but individual patients may perform better with one versus the other based on identified risk factors.
Bao Ngoc N. Tran,Austin D. Chen,Parisa Kamali,Dhruv Singhal,Bernard T. Lee,Eugene Y. Fukudome 대한성형외과학회 2018 Archives of Plastic Surgery Vol.45 No.5
Background Complication rates after flap coverage for pressure ulcers have been high historically. These patients have multiple risk factors associated with poor wound healing and complications including marginal nutritional status, prolonged immobilization, and a high comorbidities index. This study utilizes the National Surgical Quality Improvement Program (NSQIP) to examine perioperative outcomes of flap coverage for pressure ulcers. Methods Data from the NSQIP database (2005–2015) for patient undergoing flap coverage for pressure ulcers was identified. Demographic, perioperative information, and complications were reviewed. One-way analysis of variance and Pearson chi-square were used to assess differences for continuous variables and nominal variables, respectively. Multivariate logistic regression was performed to identify independent risk factors for complications. Results There were 755 cases identified: 365 (48.3%) sacral ulcers, 321 (42.5%) ischial ulcers, and 69 (9.1%) trochanteric ulcers. Most patients were older male, with some degree of dependency, neurosensory impairment, high functional comorbidities score, and American Society of Anesthesiologists class 3 or above. The sacral ulcer group had the highest incidence of septic shock and bleeding, while the trochanteric ulcer group had the highest incidence of superficial surgical site infection. There was an overall complication rate of 25% at 30-day followup. There was no statistical difference in overall complication among groups. Total operating time, diabetes, and non-elective case were independent risk factors for overall complications. Conclusions Despite patients with poor baseline functional status, flap coverage for pressure ulcer patients is safe with acceptable postoperative complications. This type of treatment should be considered for properly selected patients.