http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
The Effect of Prior Financial Performance on Organizational Reputation and Earnings Management
Quang Linh HUYNH,Nguyen Van NGUYEN2 한국유통과학회 2019 The Journal of Asian Finance, Economics and Busine Vol.6 No.4
The paper aims to investigate the linkage among prior financial performance, organizational reputation and earnings quality. Firstly, it examines the influence of prior financial performance on organizational reputation and on earnings quality. Secondly, this research explores the moderating role that prior financial performance plays in the causal relationship from organizational reputation to earnings quality. Thirdly, the mediating role of organizational reputation in the effect of prior financial performance on earnings quality is analyzed. The empirical findings show that, prior financial performance positively affects both earnings quality and organizational reputation that in turn partly mediates the causal connection from prior financial performance to earnings quality; whereas prior financial performance imposes a positive moderation in the influence of organizational reputation on earnings quality. This research is expected to provide scholars and practitioners with a thorough understanding of the complex link among prior financial performance, organizational reputation and earnings quality. That helps them to deliver good decisions on the investment of suitable resources in maintaining and enhancing their organizational reputation, which assures a higher quality of reported earnings that in turn improves involved stakeholders’ confidence in their firm. This likely leads the firms to gain better performance in the future.
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%.
MARCINKIEWICZ-ZYGMUND LAW OF LARGE NUMBERS FOR BLOCKWISE ADAPTED SEQUENCES
Quang Nguyen Van,Thanh Le Van Korean Mathematical Society 2006 대한수학회보 Vol.43 No.1
In this paper we establish the Marcinkiewicz-Zygmund strong law of large numbers for blockwise adapted sequences. Some related results are considered.
Nguyen Van Hung,Bui Thi Minh Nguyet,Nguyen Huu Nghi,Nguyen Mau Thanh,Nguyen Duc Vu Quyen,Vo Thang Nguyen,Dao Ngoc Nhiem,Dinh Quang Khieu 대한환경공학회 2023 Environmental Engineering Research Vol.28 No.3
In this study, longan seeds - an agricultural by-product was used to fabricate activated carbon (LSAC) through two-step pyrolysis with pre-carbonization at low temperature in the first step and then activation by H3PO4. LSAC with large surface area and porous structure exhibits an excellent capacity of absorption towards both cationic dyes (methylene blue (MB), rhodamine-B (RhB)) and anionic dyes (methyl orange (MO), congo red (CR)). Experimental data can be described well by the pseudo-second kinetic model. The maximum adsorption capacity based on Langmuir isotherm model was found as 502.84; 397.77; 464.66 and 350.64 mg.g−1 for MB, RhB, MO and CR, respectively. The adsorption of MB, RhB and CR on LSAC is spontaneous and endothermic, while that for MO is spontaneous but exothermic. Furthermore, the adsorption mechanism of dyes on LSAC was also studied showing that it can occur by electrostatic interaction, hydrogen bonding, the filling of pores involving the interaction between dye ions with specific functional groups such as –OH, –COOH, –NH2 and –PO43− on the LSAC surface. These results suggest that LSAC material may be envisaged as a promising adsorbent for treatment of wastewater in textile industries.
Synthesis of Carbon Nanotubes on Steel Foils
Nguyen Van Chuc,Nguyen Duc Dung,Phan Ngoc Hong,Le Dinh Quang,Phan Hong Khoi,Phan Ngoc Minh 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.5
Carbon nanotubes (CNTs) were synthesized by using a thermal chemical vapor deposition (CVD) at 800 ℃ in a mixture of C₂H₂, H₂ and N₂ gases with steel foils as both catalysts and substrates. More than 2 grams of CNTs were grown on approximately 7 grams of steel foil with a 0.5 cm² surface area after 30 minutes of growth. The effects of CVD parameters, such as the growth temperature and the deposition time, on the size and the morphology of the CNTs were studied using scanning electron microscopy (SEM). We found that the optimized temperature and growth time for having high quality CNTs were 800 ℃ and 30 minutes, respectively. The purity of the CNTs was evaluated by using thermogravimetric analysis (TGA) and the result showed that the carbon content was approximately 93 wt.%. The graphite crystallinity of the CNTs was analyzed by using Raman spectroscopy. The steel foil was found to maintain its catalytic behavior after several growths. The technique holds great promise for use in mass production (approximately 120 grams CNTs per day) with signicantly reduced cost. Carbon nanotubes (CNTs) were synthesized by using a thermal chemical vapor deposition (CVD) at 800 ℃ in a mixture of C₂H₂, H₂ and N₂ gases with steel foils as both catalysts and substrates. More than 2 grams of CNTs were grown on approximately 7 grams of steel foil with a 0.5 cm² surface area after 30 minutes of growth. The effects of CVD parameters, such as the growth temperature and the deposition time, on the size and the morphology of the CNTs were studied using scanning electron microscopy (SEM). We found that the optimized temperature and growth time for having high quality CNTs were 800 ℃ and 30 minutes, respectively. The purity of the CNTs was evaluated by using thermogravimetric analysis (TGA) and the result showed that the carbon content was approximately 93 wt.%. The graphite crystallinity of the CNTs was analyzed by using Raman spectroscopy. The steel foil was found to maintain its catalytic behavior after several growths. The technique holds great promise for use in mass production (approximately 120 grams CNTs per day) with signicantly reduced cost.
Nguyen Xuan Nhiem,Pham Hai Yen,Nguyen Thi Thanh Ngan,TRANHONG QUANG,Phan Van Kiem,Chau Van Minh,Bui Huu Tai,Nguyen Xuan Cuong,Seok Bean Song,김영호 한국식품영양과학회 2012 Journal of medicinal food Vol.15 No.4
Momordica charantia is used to treat various diseases, including inflammatory conditions. Previous reports indicated that the extract of this plant inhibits activation of nuclear transcription factor-jB (NF-jB) but activates peroxisome proliferator-activated receptor (PPAR). Additionally, cucurbitane-type triterpene glycosides are the main bioactive components of the fruit of M. charantia. Therefore, we investigated the anti-inflammatory activity of 17 cucurbitane-type triterpene glycosides (1–17) isolated from this plant. Their inhibition of NF-jB and activation of PPAR activities in HepG2 cells were measured using luciferase reporter and PPAR subtype transactivation assays. Compounds 6 and 8 were found to inhibit NF-jB activation stimulated by tumor necrosis factor-a (TNFa) in a dose-dependent manner. With 50% inhibition concentration (IC50) values of 0.4 lM, compounds 6 and 8 were more potent inhibitors than the positive control, sulfasalazine (IC50 = 0.9lM). Compounds 4, 6, and 8 also inhibited TNFa-induced expressions of inducible nitric oxide synthase and cyclooxygenase-2mRNA. However, only compound 13 significantly increased PPARc transactivation.
Cytotoxic Oleane-type Triterpene Saponins from Glochidion eriocarpum
Nguyen Xuan Nhiem,김영호,Vu Kim Thu,Phan Van Kiem,Chau Van Minh,Bui Huu Tai,TRANHONG QUANG,Nguyen Xuan Cuong,Pham Hai Yen,Hye-Jin Boo,강정일,강희경 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.1
The anticancer activity of ten compounds from the aerial parts of Glochidion eriocarpum were evaluated on two human cancer cell lines, HL-60 and HCT-116. Compounds 1-4 displayed highly potent cytotoxic activity on the HCT-116 cancer cell line with IC50 values ranging of 0.41~1.16 μM. Compounds 1-4 significantly inhibited the HL-60 cell line with IC50 values ranging of 4.51~6.33 μM. These results suggested that the benzoyl group at the C-22 position in oleane-type triterpene saponins was essential for cytotoxicity towards tumor cells. Moreover, compounds 2 and 3 showed more potent cytotoxicity than compounds 1 and 4 against HL-60 and HCT-116 cells. With respect to the mechanism underlying cytotoxicity, compounds 1-4 increased chromatin condensation, a typical apoptotic characteristic in HL-60 and HCT-116 cells. In the mechanism of apoptosis induction, compounds 1-4 reduced Bcl-2expression, whereas the expression of Bax was increased compared to controls in HCT-116 cells. In addition, compounds 1-4 decreased the level of procaspase-3. The cleavage of poly (ADP-ribose) poly merase (PARP), a vital substrate of effector caspase, was observed in HCT-116 cells. Furthermore, the induction of apoptosis was also accompanied by an activation of extracellular signal-regulated kinase (ERK) and p38 kinase in HCT-116 cells. These findings provide evidence demonstrating that the pro-apoptotic effects of compounds 1-4 are mediated through the activation of ERK and p38 in HCT-116 cells.
Nguyen Van Hung,Bui Thi Minh Nguyet,Nguyen Huu Nghi,Nguyen Minh Luon,Nguyen Ngoc Bich,Le Van Thanh Son,Nguyen Trung Kien,Dao Ngoc Nhiem,Nguyen Thanh Tuoi,Dinh Quang Khieu 대한환경공학회 2024 Environmental Engineering Research Vol.29 No.4
In the present work, ZnO/g-C₃N₄/biochar was prepared, and it was used for visible-light driven photocatalytic degradation of some colorants (methylene blue, rhodamine B, methyl orange) and some antibiotics (doxycycline, ciprofloxacin, amoxicilline). Biochar was prepared by pyrolysing Phragmites australis biomass. The ZnO/g-C₃N₄/biochar composite was synthesized with the alkaline hydrolysis method. The obtained materials were characterized by X-ray diffraction, scanning electron microscopy, transition electron microscopy, energy dispersive X-ray/elemental mapping, ultraviolet-visible-diffuse reflectance spectroscopy, photoluminescence spectroscopy, nitrogen adsorption/desorption isotherms and X-ray photoelectron spectroscopy. The results show that ZnO nanoparticles with a large surface area are highly dispersed on the g-C₃N₄ particle surface and biochar. The composite exhibits superior photocatalytic degradation ability toward doxycycline, a broad-spectrum antibiotic of the tetracycline compared with individual components (ZnO or g-C₃N₄) and satisfies stability after six treatment cycles. The kinetics and degradation mechanisms of doxycyline were also addressed. In addition, the present catalyst also exhibits the photocatalytic degradation of methylene blue, rhodamine B, methyl orange, ciprofloxacin and amoxicillin in visible-light regions.