Fe-MCM-41 with highly ordered mesoporous structure and high Fe content: synthesis and application in heterogeneous catalytic wet oxidation of phenol

Khieu, Dinh Quang,Quang, Duong Tuan,Lam, Tran Dai,Phu, Nguyen Huu,Lee, Jae Hong,Kim, Jong Seung Springer-Verlag 2009 Journal of Inclusion Phenomena and Macrocyclic Che Vol.65 No.1

The Role of Monetary Policy in the New Keynesian Model: Evidence from Vietnam

Khieu van Hoang 한국국제경제학회 2015 International Economic Journal Vol.29 No.1

This paper re-designs the New Keynesian model developed by Ireland (2004 Ireland, P. N. (2004). Technology shocks in the New Keynesian model. The Review of Economics and Statistics, 86(4), 923–936. doi: 10.1162/0034653043125158 [CrossRef], [Web of Science ®] ) and then uses the Vietnamese data from January 1995 to December 2012 to estimate the model's parameters. The empirical results show that the State Bank of Vietnam had been more aggressive as well as more responsive to aggregate fluctuations in the period before August 2000 than in the latter period. Thus, this change in the policy stance could be a potential reason for the declining importance of monetary policy in generating movements in output growth, inflation, interest rate, and the output gap across the subsamples. Another notable finding is the dominant role of the cost-push shock in explaining fluctuations in inflation, interest rate, and the output gap, leading to a policy implication that more attention should be devoted to developing substitute and complement industries so as to mitigate negative effects of the cost-push shocks by reducing the degree of dependence on imports.

The determinants of bank loan recovery rates

Hinh Khieu,Donald Mullineaux,Ha-Chin Yi 한국재무학회 2010 한국재무학회 학술대회 Vol.2010 No.05

While there is a very large literature on the determinants of default on various debt instruments, relatively little is known about the factors which influence recoveries on bank loans in the default state. The issue has taken on heightened importance since Basel II permits banks to determine required capital holdings by using model-based estimates of “loss given default” which depends on the recovery rate. We measure recoveries using the “Ultimate Recovery Database” supplied by Moody’s and model the recovery rate as a function of variables reflecting loan and borrower characteristics, industry and macroeconomic conditions, and several recovery process variables. We find that loan characteristics, such as the presence of certain types of collateral, are significant determinants of recovery rates, whereas many of the borrower characteristics before default generally are not. Industry and macroeconomic conditions also are relevant, as are certain process factors such as prepackaged bankruptcies. Since trading prices on loans approximately 30 days after default are often used by practitioners (and in some academic studies) as proxies for the recovery rate, we examine whether this proxy provides a rational estimate of actual recoveries. We find that the process that drives the 30-day trading price after default differs significantly from the actual settlement recovery process.

Stakeholder Model Approach for Labor Practices Change of Cambodian Garment Industry

Sunlong Khieu,최병헌 공주대학교 KNU 기업경영연구소 2017 기업경영리뷰 Vol.8 No.2

Globally Cambodia has been one of leading countries for the garment manufacturing industry since early 1990s. Foreign investors for garment factories of Cambodia were able to maximize the profit through very low wages, unpaid overtime labor, unsafe & unhealthy working environment. So the key source of cost leadership for Cambodian garment makers was closely concerned with the notorious working condition of Cambodia. This study accessed the labor practices change of Cambodia with the impact of the external mechanism like the bilateral trade treaty with the US government (UCBTA). This study divided the labor practices trend of Cambodian garment industry into three periods; pre-UCBTA period, during UCBTA period and post UCBTA period, and picked out major features of each period. Also the working condition reform of Cambodia was reviewed from the perspective of corporate social responsibility (CSR) type. This study accessed the limitation of labor practices reform of Cambodia through the interest dynamic among three stakeholders of the garment producers, that is Cambodian government, local employee, global garment buyers. In result, the tacit collusion and interest sharing structure between Cambodian government and the garment factory owners has worked as a big barrier of labor practices reform.

Mortality in Cambodia : An 18-Month Prospective Community-based Surveillance of All-age Deaths Using Verbal Autopsies

Goyet, Sophie,Rammaert, Blandine,McCarron, Margaret,Khieu, Virak,Fournier, Isabelle,Kitsutani, Paul,Ly, Sowath,Mounts, Anthony,Letson, William G.,Buchy, Philippe,Vong, Sirenda SAGE Publications 2015 Asia-Pacific journal of public health Vol.27 No.2

<P>To estimate the 2009-2010 death rates, causes, and patterns of mortality in rural Cambodia, we conducted active, population-based death surveillance in 25 rural villages of Cambodia from March 2009 to August 2010. Among the population of 28 053 under surveillance, 280 deaths were reported and explored by physician-certified verbal autopsies, using the International Classification of Diseases 10, yielding an overall mortality rate (MR) of 6.7/1000 persons-year (95% CI 5.74-7.68). The MR was 39.1/1000 live births for those younger than 5 years old. Infants accounted for 5.4% of all deaths. In children younger than 5 years, infectious and parasitic diseases were the leading causes of death. In children 5 to 14 years, 3 out of 4 deaths were due to injuries. Adult deaths were mainly attributed to noncommunicable diseases (52%). We conclude that this rural population is facing a substantial burden of noncommunicable diseases while still struggling with infectious diseases, respiratory diseases in particular.</P>

Synthesis of ternary core-shell carbon sphere@α-Fe2O3@Ag composites and their application for simultaneous voltammetric detection of uric acid, xanthine, and hypoxanthine

Ho Van Minh Hai,Dinh Quang Khieu,The Ky Vo,Van Cuong Nguyen,김진수 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.3

Core-shell carbon sphere (CS)@α-Fe2O3@Ag was synthesized via a multistep hydrothermal method. First, the D-glucose hydrothermal process was employed to synthesize micron-size CSs on which α-Fe2O3 was grown to obtain the composite sphere of CS@α-Fe2O3. Thereafter, Ag+ was reduced on the surface of the CS@α-Fe2O3 sphere using NaBH4 agent to produce the core-shell CS@α-Fe2O3@Ag. Finally, microsphere composite CS@α-Fe2O3@Ag was coated on a glassy carbon electrode (GCE) to enhance its electrochemical performance in the simultaneous determination of uric acid (UA), xanthine (XN), and hypoxanthine (HP). Results indicated that the CS@α-Fe2O3@Ag-coated GCE exhibited improved voltammetric sensitivity toward UA, XN, and HP compared to bare GCE. The oxidation peak currents of the simultaneous detection of UA, XN, and HP increased linearly in the concentration range of 0.5–8.0 µmol L−1. The detection limits of the fabricated electrodes for UA, XN, and HP were −0.042, 0.089, and 0.048 µmol L−1, respectively, being more sensitive than many other modified GCEs. Moreover, the CS@α-Fe2O3@Ag-coated GCE exhibited good stability and repeatability. This study opens a new perspective for developing highly efficient electrodes for electrochemical analysis.

Ringing the Bell: Does it Matter and Why?

Steve D. Dolvin,Hinh D. Khieu,Mark K. Pyles 사람과세계경영학회 2009 Global Business and Finance Review Vol.14 No.2

We explore the ongoing debate between market efficiency and behavioral finance by examining the market’ s reaction to what most investors would consider an information-neutral event: a firm ringing the opening or closing bell on the NYSE. Consistent with behavioral theories, we find that firms who ring the opening bell experience, on average, a positive abnormal return on the event day; however, we find that the reaction is concentrated in a particular group of participants. Specifically, we find the abnormal returns are driven almost entirely by firms who are celebrating the transfer of their stock listing to the NYSE. Given the potential benefits and signals associated with such an event, the favorable reaction is more consistent with market efficiency than any type of behavioral bias (i.e., the event is not information- neutral). In a more general sense, we caution against blanket conclusions of inefficiency that may result from a failure to more closely examine underlying causes for certain market reactions.

저심도 도로터널 화재시 터널 각도가 화원의 열방출율에 미치는 영향에 대한 실험 연구

김지태(Ji Tae Kim),하 티엔 키우(He Thien Khieu),유홍선(Hong Sun Ryou) 대한기계학회 2019 대한기계학회 춘추학술대회 Vol.2019 No.11

Molecular Diagnosis of Taenia saginata Tapeworms from Two Residents of Northern Cambodia

장태희,정봉광,손운목,홍수지,신혜주,류승완,이정규,Keon-HoonLEE,Virak Khieu,Rekol Huy,채종일 대한기생충학ㆍ열대의학회 2020 The Korean Journal of Parasitology Vol.58 No.2

Taenia saginata infection has seldom been reported in Cambodia. In this study, we performed a survey of intestinal parasites in 1,156 residents of Preah Vihear and Stung Treng Provinces in 2018. The results revealed that 26 (2.4%) cases were positive for Taenia spp. eggs. In order to obtain the strobilae of the tapeworms, 2 patients in Preah Vihear were treated with praziquantel and purged with magnesium salts. The proglottids expelled after the medication were morphologically and molecularly analyzed to determine the species. The main uterine lateral braches in gravid proglottids were > 15 in number suggesting that they are either T. saginata or Taenia asiatica. The sequences of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene and 2 nuclear loci, elongation factor-1 alpha (ef1) and ezrin-radixin-moesin-like protein (elp), were identical to the sequences of T. saginata available in GenBank but distant from Taenia solium, T. asiatica, and T. saginata-T. asiatica hybrid. This is the first report of the presence of T. saginata in the northern part of Cambodia bordering Lao PDR based on a molecular confirmation.

Gas sensor based on nanoporous hematite nanoparticles: Effect of synthesis pathways on morphology and gas sensing properties

Nguyen Duc Cuong,Tran Thai Hoa,Dinh Quang Khieu,Nguyen Duc Hoa,Nguyen Van Hieu 한국물리학회 2012 Current Applied Physics Vol.12 No.5

The development of a low cost and scalable gas sensor for the detection of toxic and flammable gases with fast response and high sensitivity is extremely important for monitoring environmental pollution. In this work, we introduce two different synthesis pathways for the preparation of scalable Fe2O3nanoparticles for gas sensor applications. One is co-precipitation and the other is hydrothermal method. The gas sensing properties of the a-Fe2O3 nanoparticles (NPs) fabricated by different synthesis pathways were studied and compared. The performance of the NPs in the detection of toxic and flammable gases such as carbon dioxide, ammonia, liquefied petroleum gas, ethanol, and hydrogen was evaluated. The Fe2O3 NP-based gas sensors exhibited high sensitivity and a response time of less than a minute to analytic gases. However, the NPs fabricated by the one-step direct method exhibited higher sensitivities than those generated by the a-Fe2O3 NPs obtained by co-precipitation synthesis possibly because of their nanoporous structure. This performance is attributed to the large specific surface area of the NPs, which results in higher sensitivity. The development of a low cost and scalable gas sensor for the detection of toxic and flammable gases with fast response and high sensitivity is extremely important for monitoring environmental pollution. In this work, we introduce two different synthesis pathways for the preparation of scalable Fe2O3nanoparticles for gas sensor applications. One is co-precipitation and the other is hydrothermal method. The gas sensing properties of the a-Fe2O3 nanoparticles (NPs) fabricated by different synthesis pathways were studied and compared. The performance of the NPs in the detection of toxic and flammable gases such as carbon dioxide, ammonia, liquefied petroleum gas, ethanol, and hydrogen was evaluated. The Fe2O3 NP-based gas sensors exhibited high sensitivity and a response time of less than a minute to analytic gases. However, the NPs fabricated by the one-step direct method exhibited higher sensitivities than those generated by the a-Fe2O3 NPs obtained by co-precipitation synthesis possibly because of their nanoporous structure. This performance is attributed to the large specific surface area of the NPs, which results in higher sensitivity.