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New dynamic permeability upscaling method for flow simulation under depletion drive and no-crossflow conditions

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Petroleum Science 2013年第2期10卷 233-241页

作者： Mohammad Sharifi Mohan Kelkar McDougall School of Petroleum Engineering The University of Tulsa800 South Tucker DriveTulsaOklahoma74104United States

The main purpose of upscaling in reservoir simulation is to capture the dynamic behavior of fine scale models at the coarse scale. Traditional static or dynamic methods use assumptions about the boundary conditions to determine the upscaled properties, in this paper, we show that the upscaled properties are strongly dependent on the flow process observed at the fine scale. We use a simple no- crossflow depletion drive process and demonstrate that an upscaled property is not a constant value. Instead, if the goal is to match the performance of the fine scale model, the upscaled permeability changes with time. We provide an analytical solution to determine the upscaled permeability and present the value of upscaled permeability under limiting conditions. Our equation suggests that it is possible that upscaled value can fall outside the range of fine scale values under certain conditions. We show that for pseudo steady state flow, using common averaging methods like arithmetic or even geometric averaging methods can lead to optimistic results. We also show that the no-crossflow solution is significantly different than crossflow solution at late times. We validate our method by comparing the results of the method with flow simulation results in two and multi-layered models.

关键词： Upscaling permeability reservoir simulation no-crossflow depletion drive

Pseudogenization of the Humanin gene is common in the mitochondrial DNA of many vertebrates

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Zoological Research 2017年第4期38卷 198-202页

作者： lan S. Logan 22 Parkside drive Exmouth Devon UK

In the human the peptide Humanin is produced from the small Humanin gene which is embedded as a gene-within-a-gene in the 16S ribosomal molecule of the mitochondrial DNA （mtDNA）. The peptide itself appears to be significant in the prevention of cell death in many tissues and improve cognition in animal models. By using simple data mining techniques, it is possible to show that 99.4% of the human Humanin sequences in the GenBank database are unaffected by mutations. However, in other vertebrates, pseudogenization of the Humanin gene is a common feature; occurring apparently randomly in some species and not others. The persistence, or loss, of a functional Humanin gene may be an important factor in laboratory animals, especially if they are being used as animal models in studies of Alzheimer＇s disease （AD）. The exact reason why Humanin underwent pseudogenization in some vertebrate species during their evolution remains to be determined. This study was originally planned to review the available information about Humanin and it was a surprise to be able to show that pseudogenization has occurred in a gene in the mtDNA and is not restricted solely to chromosomal genes.

关键词： mtDNA Humanin Pseudogenization NUMT

Biological and cultural diversity in the context of botanic garden conservation strategies

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Plant Diversity 2017年第6期39卷 396-401页

作者： Christopher P.Dunn Cornell Botanic Gardens 124 Comstock Knoll Drive Cornell University

Impacts of global climate change, habitat loss, and other environmental changes on the world's biota and peoples continue to increase, especially on islands and in high elevation areas. Just as floristic diversity is affected by environmental change, so too are cultural and linguistic diversity. Of the approximately 7000 extant languages in the world, fully 50% are considered to be at risk of extinction, which is considerably higher than most estimates of extinction risks to plants and animals. To maintain the integrity of plant life, it is not enough for botanic gardens to consider solely the effects of environmental change on plants within the context of major conservation strategies such as the Global Strategy for Plant Conservation and the Convention on Biological Diversity. Rather, botanic gardens should actively engage in understanding and communicating the broader impacts of environmental change to biological and cultural diversity.

关键词： Biocultural diversity Botanic gardens Linguistic diversity Plant diversity

Visualizing Photodynamic Therapy in Transgenic Zebrafish Using Organic Nanoparticles with Aggregation-Induced Emission

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Nano-Micro Letters 2018年第4期10卷 61-69页

作者： Purnima Naresh Manghnani Wenbo Wu Shidang Xu Fang Hu Cathleen Teh Bin Liu Department of Chemical and Biomolecular Engineering National University of Singapore 4 Engineering Drive 4 Institute of Molecular and Cell Biology Proteos BuildingBiopolis Drive

Photodynamic therapy(PDT) employs accumulation of photosensitizers(PSs) in malignant tumor tissue followed by the light-induced generation of cytotoxic reactive oxygen species to kill the tumor cells. The success of PDT depends on optimal PS dosage that is matched with the ideal power of light. This in turn depends on PS accumulation in target tissue and light administration time and *** theranostic nanomedicine is driven by multifunctional therapeutics that aim to achieve targeted tissue delivery and image-guided therapy, fluorescent PS nanoparticle(NP)accumulation in target tissues can be ascertained through fluorescence imaging to optimize the light dose and administration parameters. In this regard, zebrafish larvae provide a unique transparent in vivo platform to monitor fluorescent PS bio-distribution and their therapeutic efficiency. Using fluorescent PS NPs with unique aggregation-induced emission characteristics, we demonstrate for the first time the real-time visualization of polymeric NP accumulation in tumor tissue and, more importantly, the best time to conduct PDT using transgenic zebrafish larvae with inducible liver hyperplasia as an example.

关键词： Nanomedicine Photodynamic therapy Transgenic zebrafish Aggregation-induced emission Organic nanoparticles

Review of post-combustion carbon dioxide capture technologies using activated carbon

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Journal of Environmental Sciences 2019年第9期31卷 46-63页

作者： Alivia Mukherjee Jude A.Okolie Amira Abdelrasoul Catherine Niu Ajay K.Dalai Department of Chemical and Biological Engineering University of Saskatchewan Saskatoon 57 Campus Drive

Carbon dioxide(CO2) is the largest anthropogenic greenhouse gas(GHG) on the planet contributing to the global warming. Currently, there are three capture technologies of trapping CO2 from the flue gas and they are pre-combustion, post-combustion and oxy-fuel combustion. Among these, the post-combustion is widely popular as it can be retrofitted for a short to medium term without encountering any significant technology risks or *** carbon is widely used as a universal separation medium with series of advantages compared to the first generation capture processes based on amine-based scrubbing which are inherently energy intensive. The goal of this review is to elucidate the three CO2 capture technologies with a focus on the use of activated carbon(AC) as an adsorbent for post-combustion anthropogenic CO2 flue gas capture prior to emission to atmosphere. Furthermore, this coherent review summarizes the recent ongoing research on the preparation of activated carbon from various sources to provide a profound understanding on the current progress to highlight the challenges of the CO2 mitigation efforts along with the mathematical modeling of CO2 capture. AC is widely seen as a universal adsorbent due to its unique properties such as high surface area and porous texture. Other applications of AC in the removal of contaminants from flue gas, heavy metal and organic compounds, as a catalyst and catalyst support and in the electronics and electroplating industry are also discussed in this study.

关键词： Post-combustion Greenhouse gas Carbon dioxide capture Activated carbon Adsorption

Substitutional doping in 2D transition metal dichalcogenides

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Nano Research 2021年第6期14卷 1668-1681页

作者： Leyi Loh Zhepeng Zhang Michel Bosman Goki Eda Department of Physics National University of Singapore2 Science Drive 3Singapore117551Singapore Department of Materials Science and Engineering National University of Singapore9 Engineering Drive 1Singapore117575Singapore Department of Chemistry National University of Singapore3 Science Drive 3Singapore117543Singapore Centre for Advanced 2D Materials National University of Singapore2 Science Drive 2Singapore117542Singapore

Two-dimensional(2D)van der Waals transition metal dichalcogenides(TMDs)are a new class of electronic materials offering tremendous opportunities for advanced technologies and fundamental *** to conventional semiconductors,substitutional doping is key to tailoring their electronic properties and enabling their device ***,we review recent progress in doping methods and understanding of doping effects in group 6 TMDs(MX2,M=Mo,W;X=S,Se,Te),which are the most widely studied model 2D semiconductor *** and theoretical studies have shown that a number of different elements can substitute either M or X atoms in these materials and act as n-or p-type *** review will survey the impact of substitutional doping on the electrical and optical properties of these materials,discuss open questions,and provide an outlook for further studies.

关键词： substitutional doping transition metal dichalcogenide two-dimensional semiconductor acceptor donor

Investigation of material removal characteristics of Si(100)wafer during linear field atmospheric-pressure plasma etching

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Nanotechnology and Precision Engineering 2020年第4期3卷 244-249页

作者： Weijia Guo Senthil Kumar A. Peng Xu Department of Mechanical Engineering National University of Singapore9 Engineering Drive 1117575Singapore Singapore Institute of Manufacturing Technology 73 Nanyang Drive637662Singapore

Atmospheric-pressure(AP)plasma etching provides an alternative method for mechanical grinding to realize wafer thinning of Si *** can avoid the damages and micro-cracks that would be introduced by mechanical stress during the grinding *** this study,the material removal characteristics of Si(100)wafer processed by linear field AP plasma generated using carbon tetrafluoride(CF4)as the reactive source were *** linear field plasma etching tool has a typical removal profile and the depth removal rate that can reach up to 1.082μm/*** effect ofO2 concentration on the removal ratewas discussed and the surfacemorphology during the process was characterized using scanning electron *** is shown that the subsurface damage layer was gradually removed during the etching process and the surface was observed to be smoothened with the increase of the etching *** present work contributes a basic understanding of the linear field AP plasma etching performance with different gas composition and the typical characteristics would be further applied to damage-free precision removal of Si.

关键词： AP plasma etching Removal characteristics Oxygen effect Surface morphology

ROBOD, room-level occupancy and building operation dataset

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Building Simulation 2022年第12期15卷 2127-2137页

作者： Zeynep Duygu Tekler Eikichi Ono Yuzhen Peng Sicheng Zhan Bertrand Lasternas Adrian Chong Department of the Built Environment National University of Singapore4 Architecture Drive117566Singapore

The availability of the building’s operation data and occupancy information has been crucial to support the evaluation of existing models and development of new data-driven *** paper describes a comprehensive dataset consisting of indoor environmental conditions,Wi-Fi connected devices,energy consumption of end uses(i.e.,HVAC,lighting,plug loads and fans),HVAC operations,and outdoor weather conditions collected through various heterogeneous sensors together with the ground truth occupant presence and count information for five rooms located in a university *** five rooms include two different-sized lecture rooms,an office space for administrative staff,an office space for researchers,and a library space accessible to all students.A total of 181 days of data was collected from all five rooms at a sampling resolution of 5 *** dataset can be used for benchmarking and supporting data-driven approaches in the field of occupancy prediction and occupant behaviour modelling,building simulation and control,energy forecasting and various building analytics.

关键词： building operation data occupancy data sensor fusion occupancy prediction building simulation and control

Development，Application，Markets，and　Patent　Situation　of　Magnetostrictive　TERFENOL－D

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Journal of Rare Earths 1995年第4期13卷 295-301页

作者： McMasters, O.D. ETREMA Products Inc. 2500 North Loop Drive Ames Iowa 50010

The development of the giant magnetostrictive rare earth-iron materials is reported from their discovery in the early 1970's to their present use in transducer and sensor applications. Fifteen broad market areas, ranging from miniature devices in the medical industry to high powder sonar and seismic sources have been identified. A world-wide customer base in these high technology fields has been established and the superior properties of these materials are responsible for the rapid growth of the magnetostrictive transducer industries. The critical design criteria that lead to efficient devices are reported and the performance of several of these products is presented. The key patents associated with these giant magnetostrictive materials and devices using these materials are reviewed. The present and future of these technologies in reference to commercialization, market growth and the impact on the many transduction industries are discussed. (Author abstract) 9 Refs.

关键词： Magnetostrictive Situation Patent TERFENOL and Development Application