동아시아 세계 속 베트남 목간 연구 서설 (1) 경계를 넘나드는 ‘봉함목간’, ‘목협’, ‘협판’

Pham Le Huy,김현경(번역자) 한국목간학회 2021 목간과 문자 Vol.- No.27

일본에서 출토된 목간 중에는 ‘봉함목간(封緘木簡)’이라는 특수한 목간의 카테고리가 있다. 일부 봉함목간은 행정문서 자체를 직접 끼워서 봉함하기 위해 사용된 것으로 추정되고 있는데, 그러한 추정은 어디까지나 실물의 관찰에서 도출된 것으로, 문헌사료로는 충분히 뒷받침되지 못하였다. 그렇기 때문에 본고에서는 베트남 관련 문헌사료에 대한 분석을 바탕으로 9세기부터 18세기에 걸친 중국과의 외교문서를 봉하기 위한 ‘목협(木夾)’과 ‘협판(夾板)’의 존재를 지적하고, 봉함목간의 용도를 문헌사료를 통해 확인하며, 또한 동아시아의 봉함목간에 대한 이해를 심화하고자 한다. Among the wooden tablets excavated in Japan, there is a special category of wooden tablets called fukan mokkan, which means “sealed wooden tablet(s)”. It is thought that one of the usages of fukan mokkan is to sandwich and seal the administrative documents, but that presumption was raised just from the observation of the wooden tablets themselves, not fully supported by historical documents. Therefore, in this paper, in order to clarify the usage and deepen the understanding of sealed wooden tablets in the East Asia World, through analyzing the historical documents related to Vietnam, I would like to point out the existence of sealed wooden tablets in Vietnam, which was used to seal the diplomatic documents sending to China from the 9th century to the 18th century.

Nano-porous Silicon Microcavity Sensors for Determination of Organic Fuel Mixtures

Van Hoi Pham,Huy Bui,Le Ha Hoang,Thuy Van Nguyen,The Anh Nguyen,Thanh Son Pham,Quang Minh Ngo 한국광학회 2013 Current Optics and Photonics Vol.17 No.5

We present the preparation and characteristics of liquid-phase sensors based on nano-porous silicon multilayer structures for determination of organic content in gasoline. The principle of the sensor is a determination of the cavity-resonant wavelength shift caused by refractive index change of the nano-porous silicon multilayer cavity due to the interaction with liquids. We use the transfer matrix method (TMM)for the design and prediction of characteristics of microcavity sensors based on nano-porous silicon multilayer structures. The preparation process of the nano-porous silicon microcavity is based on electrochemical etching of single-crystal silicon substrates, which can exactly control the porosity and thickness of the porous silicon layers. The basic characteristics of sensors obtained by experimental measurements of the different liquids with known refractive indices are in good agreement with simulation calculations. The reversibility of liquid-phase sensors is confirmed by fast complete evaporation of organic solvents using a low vacuum pump. The nano-porous silicon microcavity sensors can be used to determine different kinds of organic fuel mixtures such as bio-fuel (E5), A92 added ethanol and methanol of different concentrations up to 15%.

Improvement in carrier collection at the i/n interface of graded narrow-gap hydrogenated amorphous silicon germanium solar cells

Pham, Duy Phong,Kim, Sangho,Park, Jinjoo,Le, Anh Huy Tuan,Cho, Jaehyun,Yi, Junsin ELSEVIER SCIENCE 2017 JOURNAL OF ALLOYS AND COMPOUNDS Vol.724 No.-

<P><B>Abstract</B></P> <P>We examined different buffer layers at the i/n interface of narrow-gap amorphous silicon germanium alloy (a-SiGe:H)-based thin-film solar cells. These buffers included a conventional hydrogenated amorphous silicon (a-Si:H), an inversely graded hydrogenated amorphous silicon germanium, and a crystalline seed buffer (CSB). The solar cell with the CSB shows the highest performance, of 10%. The better carrier extraction at the rear side of the device is attributed to the role of the CSB layer. The effect of CSB thickness from 50 nm to 100 nm on cell performance was examined. Cell efficiency increased with the buffer thickness up to 80 nm and decreased with buffer thickness of 100 nm. This decrease can be attributed to increased defect densities of the buffer due to less efficient passivation of amorphous phase at the crystalline column boundaries.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Carrier extraction at the i/n interface is improved by crystalline seed buffer (CSB) layer. </LI> <LI> Role of crystalline seed buffer layer is discussed in detail. </LI> <LI> High efficiency of 10% of graded a-SiGe:H thin film solar cell is obtained with CSB buffer. </LI> </UL> </P>

Controlling a crystalline seed layer for mirocrystalline silicon oxide window layer in rear emitter silicon heterojunction cells

Pham, Duy Phong,Kim, Sangho,Lee, Sunhwa,Le, Anh Huy Tuan,Cho, Eun-Chel,Park, Jinjoo,Yi, Junsin Elsevier 2019 Infrared physics & technology Vol.102 No.-

<P><B>Abstract</B></P> <P>Remarkable progress has been made in the improvement of rear-emitter silicon heterojunction (RE-SHJ) solar cells with the use of very thin n-type front contact layers. However, further reducing the thickness of the front window layers while maintaining high conductivity for mitigating the parasitic absorption and carrier collection loss has proven challenging. In this study, we implement controlling a seed layer for achieving ultra-thin, high crystalline and conductivity of n-type hydrogenated microcrystalline silicon oxide (n-µc-SiO<SUB>x</SUB>:H) front window layer in RE-SHJ solar cells. By using a seed layer, the crystallinity confirmed by Raman and TEM measurements, and the conductivity of the n-µc-SiO<SUB>x</SUB>:H front layers are significantly enhanced compared with that without using the seed layer. This leads to a remarkable increase in the open-circuit voltage (<I>V</I> <SUB>oc</SUB>) by 6 mV and fill factor (<I>FF</I>) by 4.11% while maintaining a high short-circuit current density (<I>J</I> <SUB>sc</SUB>) in range of 38 mA/cm<SUP>2</SUP>. A high cell performance of 21.1% is obtained with the use of an optimised seed layer.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Effect of deposition power densities on seed-growth via TEM measurement was discussed. </LI> <LI> High crystallinity and conductivity of ultra-thin n-µc-SiOx:H front layer for RE-SHJ solar cells. </LI> <LI> V<SUB>oc</SUB> enhancement by 6 mV and fill factor by 4.11% due to optimization of seed layer. </LI> </UL> </P>

Discordance between quantitative ultrasound and dual-energy X-ray absorptiometry in bone mineral density: The Vietnam Osteoporosis Study

Huy G. Nguyen,Khanh B. Lieu,Thao P. Ho-Le,Lan T. Ho-Pham,Tuan V. Nguyen 대한골다공증학회 2021 Osteoporosis and Sarcopenia Vol.7 No.1

Objectives: Calcaneal quantitative ultrasound measurement (QUS) has been considered an alternative to dual-energy X-ray absorptiometry (DXA) based bone mineral density (BMD) for assessing bone health. This study sought to examine the utility of QUS as an osteoporosis screening tool by evaluating the correlation between QUS and DXA. Methods: The study was a part of the Vietnam Osteoporosis Study that involved 1270 women and 773 men aged 18 years and older. BMD at the femoral neck, total hip and lumbar spine was measured using DXA. Osteoporosis was diagnosed based on the femoral neck T-score using World Health Organization criteria. Broadband ultrasound attenuation (BUA) at the calcaneus was measured by QUS. The concordance between BUA and BMD was analyzed by the linear regression model. Results: In all individuals, BUA modestly correlated with femoral neck BMD (r ¼ 0.35; P < 0.0001) and lumbar spine BMD (r ¼ 0.34; P < 0.0001) in both men and women. In individuals aged 50 years and older, approximately 16% (n ¼ 92/575) of women and 3.2% (n ¼ 10/314) of men were diagnosed to have osteoporosis. Only 0.9% (n ¼ 5/575) women and 1.0% (n ¼ 3/314) men were classified as “Low BUA”. The kappa coefficient of concordance between BMD and BUA classification was 0.09 (95% CI, 0.04 to 0.15) for women and 0.12 (95% CI, 0.03 to 0.22) for men. Conclusions: In this population-based study, QUS BUA modestly correlated with DXA BMD, suggesting that BUA is not a reliable method for screening of osteoporosis

Line Impedance Estimation Based Adaptive Droop Control Method for Parallel Inverters

Le, Phuong Minh,Pham, Xuan Hoa Thi,Nguyen, Huy Minh,Hoang, Duc Duy Vo,Nguyen, Tuyen Dinh,Vo, Dieu Ngoc The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.1

This paper presents a new load sharing control for use between paralleled three-phase inverters in an islanded microgrid based on the online line impedance estimation by the use of a Kalman filter. In this study, the mismatch of power sharing when the line impedance changes due to temperature, frequency, significant differences in line parameters and the requirements of the Plug-and-Play mode for inverters connected to a microgrid has been solved. In addition, this paper also presents a new droop control method working with the line impedance that is different from the traditional droop algorithm when the line impedance is assumed to be pure resistance or pure inductance. In this paper, the line impedance estimation for parallel inverters uses the minimum square method combined with a Kalman filter. In addition, the secondary control loops are designed to restore the voltage amplitude and frequency of a microgrid by using a combined nominal value SOGI-PLL with a generalized integral block and phase lock loop to monitor the exact voltage magnitude and frequency phase at the PCC. A control model has been simulated in Matlab/Simulink with three voltage source inverters connected in parallel for different ratios of power sharing. The simulation results demonstrate the accuracy of the proposed control method.

Novel 3,4-dihydro-4-oxoquinazoline-based acetohydrazides: Design, synthesis and evaluation of antitumor cytotoxicity and caspase activation activity

Huan, Le Cong,Tran, Phuong-Thao,Phuong, Cao Viet,Duc, Phan Huy,Anh, Duong Tien,Hai, Pham The,Huong, Le Thi Thu,Thuan, Nguyen Thi,Lee, Hye Jin,Park, Eun Jae,Kang, Jong Soon,Linh, Nguyen Phuong,Hieu, Tr Elsevier 2019 Bioorganic chemistry Vol.92 No.-

<P><B>Abstract</B></P> <P>In search for novel small molecules with antitumor cytotoxicity via activating procaspase-3, we have designed and synthesized three series of novel (E)-<I>N</I>′-benzylidene-4-oxoquinazolin-3(4<I>H</I>)-yl)acetohydrazides (<B>5a-j, 6a-h,</B> and <B>7a-h)</B>. On the phenyl ring ò the benzylidene part, three different substituents, including 2-OH-4-OCH<SUB>3</SUB>, 4-OCH<SUB>3</SUB>, and 4-N(CH<SUB>3</SUB>)<SUB>2</SUB>, were introduced, respectively. Biological evaluation showed that the acetohydrazides in series <B>5a-j</B>, in which the phenyl ring of the benzylidene part was substituted by 2-OH-4-OCH<SUB>3</SUB> substituent, exhibited potent cytotoxicity against three human cancer cell lines (SW620, colon; PC-3, prostate; NCI-H23, lung). Most of the compounds, in this series, especially compounds <B>5c, 5b</B> and <B>5h,</B> also significantly activated caspase-3 activity. Among these, compound <B>5c</B> displayed 1.61-fold more potent than PAC-1 as caspase-3 activator. Cell cycle analysis showed that compounds <B>5b</B>, <B>5c</B>, and <B>5h</B> significantly arrested the cell cycle in G1 phase. Further apoptotic studies also demonstrated compounds <B>5b</B>, <B>5c</B>, and <B>5h</B> as strong apoptotic cell death inducers. The docking simulation studies showed that these compounds could activate procaspase <I>via</I> chelating Zn<SUP>2+</SUP> ion bound to the allosteric site of the zymogen.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Novel (<I>E</I>)-<I>N</I>′-benzylidene-2-(4-oxoquinazolin-<I>3(4H)-yl</I>)acetohydrazides were synthesized. </LI> <LI> The acetohydrazides <B>5a-i</B> exhibited potent cytotoxicity against three human cancer cell lines. </LI> <LI> A number of cytotoxic compounds exhibited good caspase activation activity. </LI> <LI> The cytotoxic compounds were shown to arrest cells at G1 phase. </LI> <LI> The cytotoxic compounds were shown as strong apoptotic inducers. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Micropropagation from root segments to improve seedling quality in Chinese foxglove crops

Thanh Loan Pham,Van Huy Nguyen,Thi Le Thu Hoang,Thi Tam Tien Ha,Trung Kien Tran,Xuan Duong Vu,Phi Bang Cao,Quang Trung Nguyen 한국식물생명공학회 2020 JOURNAL OF PLANT BIOTECHNOLOGY Vol.47 No.3

This is the first study to establish a complete protocol for micropropagation of Rehmannia glutinosa from root segments. The study involved investigating the effect of plant growth regulators on in vitro shoot regeneration and rooting and identifying substrates supporting survival and growth performance of ex vitro seedlings. A Murashige and Skoog (MS) medium containing 30 g/L sucrose for shoot induction and 0.2 mg/L indole-3-acetic acid (IAA), 1 mg/L 6-benzylaminopurine (BAP), and 1 g/L polyvinylpyrrolidone (PVP) for shoot multiplication resulted in the highest number of shoots per explant and shoot height. Applying a medium containing 0.5 mg/L IAA and 1 g/L PVP yielded optimal rooting of the shoots grown in vitro. Compost enriched with microbial inoculants and perlite enhanced seedling growth better than that with organic biofertilizer-free substrates (soil and sand). We recommend the continuous production of micropropagated R. glutinosa seedlings from root segments under the aforementioned conditions as a possible propagation technique for crops of this species.

The Impact of COVID-19 Pandemic on Firm Performance: Empirical Evidence from Vietnam

BUI, Trung Huy,NGUYEN, Huong Thu,PHAM, Yen Nhu,NGUYEN, Trang Thu Thi,LE, Linh Thao,LE, Giang Thu Tran Korea Distribution Science Association 2022 The Journal of Asian Finance, Economics and Busine Vol.9 No.7

The outbreak of Coronavirus disease 2019 (COVID-19) has caused serious impacts not only on human health but also on the economies around the world. Enterprises play an important role in the development of every country but it is also one of the most affected sectors during the pandemic. Drawing on panel data of 131 enterprises listed on the Vietnamese stock exchange from 2016Q1 to 2021Q3, this study aims to investigate the impact of the COVID-19 pandemic on firm performance. Enterprises are classified into seven industries including Agriculture, Material, Industry, Real estate and Construction, Energy, Consumer, and Service. The paper also analyzes the variation of the effects among companies, focusing on differences in revenue and capital structure. The results show that the COVID-19 pandemic negatively affects business performance. In addition, the empirical findings indicate that revenue and debt decreasing can cause deterioration of firm performance during the pandemic period. The decrease in revenue has a direct impact on firm profitability. The reduction of debt levels affects the corporate leverage leading to adverse effects on firm performance. The negative effect is more pronounced for companies in some specific sectors including industry, real estate, construction, consumption, and services.

Appropriation of Protocol for Laparoscopic Pancreaticoduodenectomy in Treatment of Periampullary Cancer

( Minh Hai Pham ),( Quan Anh Tuan Le ),( Hoang Bac Nguyen ),( Quang Hung Vu ),( Thai Ngoc Huy Tran ),( Hang Dang Khoa N Guyen ),( Thi Ngoc Sang Duong ),( Van Toan Tran ) 대한간학회 2020 춘·추계 학술대회 (KASL) Vol.2020 No.1

Aims: Laparoscopic pancreaticoduodenectomy (LPD) is considered as a safe and effective procedure in well - selected patients and appropriate surgical technique. Our aim is to evaluate suitability of using protocol for LPD in treatment of periampullary cancer at a single team. Methods: case series Results: Indication for LPD included 37 cases with resectable tumors which were classified basing on NCCN. All witness evaluation risk of complications with PREPARE score, ASA and evaluation risk of postoperative pancreatic fistula (POPF) with FRS classification. There were 2 open conversions because of vein resections, accounting for 5.4%. Standard lymphadenectomy was performed in all of 37 cases. In term of PREPARE score, major complications (Clavien - Dindo >= III) were 17.8%, 0% and 0% (5/28, 0/5 and 0/2 cases) in low risk, intermediate risk and high risk group, respectively. All of cases had ASA I or II. POPF happened 11.1% (1/9), 4.1% (1/24) and 50% (1/2) in low risk, intermediate risk and high risk group, respectively. Frozen section was needed for R0 margin. Retrieved lymph nodes was 8 - 18 with 12 lymph nodes in average. Conclusions: Indication for LPD with resectable tumors is acceptable. ASA I or II is a safe measure to select patient for LPD. FRS classification shows appropriation to evaluate risk of POPF.