2-D LARGE EDDY SIMULATION OF LOCK-EXCHANGE GRAVITY CURRENT FLOWS

OOI SENG-KEAT,CONSTANTINESCU GEORGE,WEBER LARRY 한국수자원학회 2005 한국수자원학회 학술대회 Vol.2005 No.1

Oncogenic Pathway Combinations Predict Clinical Prognosis in Gastric Cancer

Ooi, Chia Huey,Ivanova, Tatiana,Wu, Jeanie,Lee, Minghui,Tan, Iain Beehuat,Tao, Jiong,Ward, Lindsay,Koo, Jun Hao,Gopalakrishnan, Veena,Zhu, Yansong,Cheng, Lai Ling,Lee, Julian,Rha, Sun Young,Chung, Hyu Public Library of Science 2009 PLoS genetics Vol.5 No.10

<▼1><P>Many solid cancers are known to exhibit a high degree of heterogeneity in their deregulation of different oncogenic pathways. We sought to identify major oncogenic pathways in gastric cancer (GC) with significant relationships to patient survival. Using gene expression signatures, we devised an <I>in silico</I> strategy to map patterns of oncogenic pathway activation in 301 primary gastric cancers, the second highest cause of global cancer mortality. We identified three oncogenic pathways (proliferation/stem cell, NF-κB, and Wnt/β-catenin) deregulated in the majority (>70%) of gastric cancers. We functionally validated these pathway predictions in a panel of gastric cancer cell lines. Patient stratification by oncogenic pathway combinations showed reproducible and significant survival differences in multiple cohorts, suggesting that pathway interactions may play an important role in influencing disease behavior. Individual GCs can be successfully taxonomized by oncogenic pathway activity into biologically and clinically relevant subgroups. Predicting pathway activity by expression signatures thus permits the study of multiple cancer-related pathways interacting simultaneously in primary cancers, at a scale not currently achievable by other platforms.</P></▼1><▼2><P><B>Author Summary</B></P><P>Gastric cancer is the second leading cause of global cancer mortality. With current treatments, less than a quarter of patients survive longer than five years after surgery. Individual gastric cancers are highly disparate in their cellular characteristics and responses to standard chemotherapeutic drugs, making gastric cancer a complex disease. Pathway based approaches, rather than single gene studies, may help to unravel this complexity. Here, we make use of a computational approach to identify connections between molecular pathways and cancer profiles. In a large scale study of more than 300 patients, we identified subgroups of gastric cancers distinguishable by their patterns of driving molecular pathways. We show that these identified subgroups are clinically relevant in predicting survival duration and may prove useful in guiding the choice of targeted therapies designed to interfere with these molecular pathways. We also identified specific gastric cancer cell lines mirroring these pathway subgroups, which should facilitate the pre-clinical assessment of responses to targeted therapies in each subgroup.</P></▼2>

Optimization of aluminium recovery from water treatment sludge using Response Surface Methodology

Ooi, Theam Yiew,Yong, Ee Ling,Din, Mohd Fadhil Md,Rezania, Shahabaldin,Aminudin, Eeydzah,Chelliapan, Shreeshivadasan,Abdul Rahman, Azlan,Park, Junboum Elsevier 2018 Journal of Environmental Management Vol.228 No.-

<P>For decades, water treatment plants in Malaysia have widely employed aluminium-based coagulant for the removal of colloidal particles in surface water. This generates huge amount of by-product, known as sludge that is either reused for land applications or disposed to landfills. As sludge contains high concentration of aluminium, both can pose severe environmental issues. Therefore, this study explored the potential to recover aluminium from water treatment sludge using acid leaching process. The evaluation of aluminium recovery efficiency was conducted in two phases. The first phase used the one factor at a time (OFAT) approach to study the effects of acid concentration, solid to liquid ratio, temperature and heating time. Meanwhile, second phase emphasized on the optimization of aluminium recovery using Response Surface Methodology (RSM). OFAT results indicated that aluminium recovery increased with the rising temperature and heating time. Acid concentration and solid to liquid ratio, however, showed an initial increment followed by reduction of recovery with increasing concentration and ratio. Due to the solidification of sludge when acid concentration exceeded 4 M, this variable was fixed in the optimization study. RSM predicted that aluminium recovery can achieve 70.3% at optimal values of 4 M, 20.9%, 90 degrees C and 4.4 h of acid concentration, solid to liquid ratio, temperature and heating time, respectively. Experimental validation demonstrated a recovery of 68.8 +/- 0.3%. The small discrepancy of 2.2 +/- 0.4% between predicted and validated recovery suggests that RSM was a suitable tool in optimizing aluminium recovery conditions for water treatment sludge.</P>

Fused Corrole Dimers Interconvert between Nonaromatic and Aromatic States through Two‐Electron Redox Reactions

Ooi, Shota,Tanaka, Takayuki,Park, Kyu Hyung,Lee, Sangsu,Kim, Dongho,Osuka, Atsuhiro WILEY‐VCH Verlag 2015 Angewandte Chemie Vol.127 No.10

<P><B>Abstract</B></P><P>A singly linked corrole dimer was synthesized by condensation of a dipyrromethane‐1‐carbinol with 1,1,2,2‐tetrapyrroethane. Oxidation of the dimer gave doubly linked corrole dimers <B>9</B> and <B>10</B> as the first examples of fused corrole dimers involving a meso–meso linkage. Dimers <B>9</B> and <B>10</B> exhibit characteristic <SUP>1</SUP>H NMR spectra, absorption spectra, excited‐state dynamics, and two‐photon absorption (TPA) values, which indicate the nonaromatic nature of <B>9</B> and the aromatic nature of <B>10</B>. Interestingly, <B>9</B> is fairly stable despite its unusual 2H‐corrole structure, which has been ascribed to the presence of two direct connections between the individual corrole units.</P>

Bonds that BindShared Historical and Sociocultural Characteristics of Southeast Asia

OOI Keat Gin 부산외국어대학교 동남아지역원 2019 Suvannabhumi Vol.11 No.1

[ Abstract ] The region between mainland China on the east and the Indian sub-continent on the west is referred to as Southeast Asia since the conclusion of the Pacific War (1941-1945). As a region, Southeast Asia appears as a hodgepodge of disparity and diversity, but a closer scrutiny reveals numerous common attributes and characteristics. This study attempts to identify and examine the cohesive and shared characteristics across the Southeast Asian region from a historical and sociocultural perspective. The intention is to differentiate an identity borne of the underlying commonalities of shared characteristics whether physical, experiential, emotive, and/or in terms of heritage. Subsequently, Southeast Asia has more grounds to claim itself as a distinct region, and an “area of study,” besides the political expediency of ASEAN.

The Singapore Field Epidemiology Service: Insights Into Outbreak Management

Ooi, Peng-Lim,Seetoh, Theresa,Cutter, Jeffery The Korean Society for Preventive Medicine 2012 Journal of Preventive Medicine and Public Health Vol.45 No.5

Field epidemiology involves the implementation of quick and targeted public health interventions with the aid of epidemiological methods. In this article, we share our practical experiences in outbreak management and in safeguarding the population against novel diseases. Given that cities represent the financial nexuses of the global economy, global health security necessitates the safeguard of cities against epidemic diseases. Singapore's public health landscape has undergone a systemic and irreversible shift with global connectivity, rapid urbanization, ecological change, increased affluence, as well as shifting demographic patterns over the past two decades. Concomitantly, the threat of epidemics, ranging from severe acute respiratory syndrome and influenza A (H1N1) to the resurgence of vector-borne diseases as well as the rise of modern lifestyle-related outbreaks, have worsened difficulties in safeguarding public health amidst much elusiveness and unpredictability. One critical factor that has helped the country overcome these innate and man-made public health vulnerabilities is the development of a resilient field epidemiology service, which includes our enhancement of surveillance and response capacities for outbreak management, and investment in public health leadership. We offer herein the Singapore story as a case study in meeting the challenges of disease control in our modern built environment.

Tristable switching of the electrical conductivity through graphene quantum dots sandwiched in multi-stacked poly(methyl methacrylate) layers

Ooi, P.C.,Lin, J.,Kim, T.W.,Li, F. Elsevier Science 2016 Organic electronics Vol.38 No.-

<P>Tristable switching nonvolatile memory (NVM) devices based on graphene quantum dots (GQDs) sandwiched between multi-stacked poly (methyl methacrylate) (PMMA) layers were fabricated on indium-tin-oxide (ITO)-coated glass substrates by using a solution-processed method. Current-voltage (I-V) curves at 300 K for the silver nanowire/PMMA/GQD/PMMA/GQD/PMMA/ITO/glass devices showed tristable switching currents with high-resistance, intermediate-resistance, and low-resistance states. The device's cycling endurance of the three resistance states remained stable with a distinguishable value for each resistance state over 1000 cycles, and the obtained retention results showed well-distinguished resistance states without degradation for up to 1 x 10(4) s. Schottky emission, Poole-Frenkel emission, trapped-charge limited-current, and ohmic conduction were proposed as the dominant conduction mechanisms for the fabricated NVM devices based on the obtained I-V characteristics. The described energy-band diagrams confirm the proposed conduction band mechanisms. (C) 2016 Published by Elsevier B.V.</P>

Southeast Asia in International History: Justification and Exploration

( Ooi Keat Gin ) 부산외국어대학교 아세안연구원(구 부산외국어대학교 동남아지역원) 2020 Suvannabhumi Vol.12 No.2

Despite its centrality at a pivotal crossroads of both land and sea of East-West trade, communications and travel, the region now known as Southeast Asia provides very few scholarly works situating or featuring it in an international context. Because of this paucity, there is immense scope for exploration. But prior to further explorations, justification is needed to establish that Southeast Asia, as a region, is a subject of interest, relevance, and significance in a global context. Southeast Asia was home to several empires whose reach transcended the region and beyond. Southeast Asia in, and as part of international history as an area of study is therefore justifiable. Moreover, other factors come into play, viz. geography, resources, migration, diffusion of ideas and beliefs from without and accommodation from within, shared experience of imperialism and colonialism, decolonization, and the Cold War, and the collective fate under the Association of Southeast Asian Nations (ASEAN), that further bolster its rationalization as a component of international history. Explorations, on the other hand, examine issues and obstacles that contribute to the paucity of works on Southeast Asia in international history. Furthermore, in contextualizing Southeast Asia in international history, there might appear challenges that need to be identified, confronted, and resolved.

Eclectic Sociocultural Traditions of the Baba Nyonya of George Town, Penang, Malaysia

( Ooi Keat Gin ) 부산외국어대학교 동남아지역원 2017 Suvannabhumi Vol.9 No.2

Strategically situated between the East-West maritime crossroads, the peoples of Southeast Asia over the centuries witnessed the comings and goings of traders from territories from East Asia, South Asia, West Asia and Europe. There were also those from North America that crossed the Pacific for commercial profits in this region. Foreign traders undoubtedly in the course of their visits and sojourns had liaisons with local women, some engaged in marriages. Offspring of these interracial miscegenation possessed rather unique characteristics. As a community, they were identified with the Malay term, peranakan, from the root word, “anak” meaning “child,” hence “offspring” or “descendent”. Specific terms - Baba Nyonya, Tionghoa-Selat, Chitty, Jawi Pekan, Pashu, Kristang - referred to particular groups. Although socially they appeared ‘neither here nor there’, members of mixed parentage were able to carve an especial niche in the local environment throughout Southeast Asia, conspicuously in urban, port-cities where trade and commerce predominated. Following in the footsteps of their progenitor, the Peranakan acted as intermediaries, comprador between foreign and indigenous enterprises, profiting financially and socially from trade and commerce. Tapping on the author’s personal experiences and first-hand observations, complementing with oral sources, and support from secondary materials, this present essay explores, discusses, and analyzes the eclectic sociocultural practices and traditions of the Baba Nyonya of George Town, Penang. Purposeful intention is to further enlighten our understanding, and in turn, our appreciation, of these ever increasingly diminishing communities and their cultures across Southeast Asia.

Effect of inlet throttling on thermohydraulic instability in a large scale water-based RCCS: A system-level analysis with RELAP5-3D

Ooi Zhiee Jhia,Lv Qiuping,Hu Rui,Jasica Matthew,Lisowski Darius 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.5

This paper presents results from system-level modeling of a water-based reactor cavity cooling system using RELAP5-3D. The computational model is benchmarked with experimental data from a half-scale RCCS test facility at Argonne National Laboratory. The model prediction is first compared with a two-phase oscillatory baseline experimental case where mixed accuracy is obtained. The model shows reasonable prediction of mass flow rate, pressure, and temperature but significant overprediction of void fraction. The model prediction is then compared with a fault case where the inlet of the risers is gradually reduced using a throttling valve. As the valve is closed, the model is able to predict some major flow phenomena observed in the experiment such as the dampening of oscillations, the reintroduction of oscillations, as well as boiling, flashing, and geysering in the risers. However, the timeline of these events are not well captured by the model. The model is also used to investigate the evolution of flow regime in the chimney. This work highlights that the semiempirical constitutive relations used in RELAP-3D could have a strong influence on the accuracy of the model in two-phase oscillatory flows.