bluuebunny/crossref_metadata_2025 huggingface dataset:
Persistence in EOR - Design of a Field Trial in a Carbonate Reservoir using Solvent-based Water-Flood Process
Authors: Alkindi Abdullah , Al-Azri Nasser , Said Dhiya , AlShuaili Khalid , Te Riele Paul
Published: March 2016

Primary and secondary recovery processes produce about one third of oil in place, leaving significant volumes behind. For low permeability and highly saline carbonate reservoirs, exploiting these resources is often challenging and unfeasible either technically and/or commercially.

In this paper we discuss the application of an emerging EOR technique that has shown promising results in the lab. Di-Methyl Ether (DME) enhanced waterflood (DEW) is a process in which DME is added to injection water, which upon injection into the reservoir, it preferentially partitions into the remaining oil. As a result, it swells the oil and reduces its viscosity which significantly improves oil mobility in the reservoir. Several core-flood experiments conducted in tight carbonate plugs have shown incremental recoveries of up-to 20% post waterflood. Additionally, the process provides significant acceleration to oil production, which would otherwise take several pore volume of water injection.

After successful PVT and core flood experiments, a field trial has been designed to de-risk this technology which if successful would add significant reserves. The pilot will be implemented in a tight carbonate reservoir that has been under waterflood. Some key uncertainties this pilot will address include solvent utilisation, oil incremental recovery, solvent back production and impact of geology on the process.

This paper discusses the key physical mechanisms of the process, pilot design and challenges of full field considerations. In addition, it also highlights key considerations when designing solvent-based EOR applications. The paper also highlights the need of lab work to mitigate operational issues prior to implementation. Calibrated numerical models were used to generate full field profiles, which show the need for a well optimised pattern design to make such processes feasible
Improving Reactive Transport Modelling Predictivity for ASP Flooding Simulations
Authors: Li Xipeng , Wei Lingli , Zhang Huanhuan
Published: March 2016

Alkaline-Surfactant-Polymer (ASP) injection into an oil reservoir triggers a series of geochemical reactions including reservoir mineral dissolution and precipitation of scales inside the reservoir and wellbores. Modelling these reactions is important for understanding the processes and designing the ASP formulation for optimal oil recovery. A number of reactive transport modelling (RTM) approaches have been reported in the literature so far, but none has addressed the importance of a geochemical database underpinning such simulations considering both equilibrium and kinetic reactions. In the meantime, experimental data available outside the oil industry can be used for calibrating reservoir mineral dissolution equilibrium constants in high pH solutions.

In this paper, experimental data of dissolution of relevant reservoir minerals and precipitation of scale minerals are compiled and compared with predictions from the widely used geochemical modelling software PHREEQC. A new database calibrated to the experimental data is developed in PHREEQC format that can be used in Shell in-house reservoir simulator MoReS for ASP flood reactive transport simulations. In order to reproduce the sequence of the observed scale deposition during an ASP flood project, the kinetic rate laws for the mineral dissolution and precipitations have also been calibrated against the experimental data.

Significant differences in the predicted mineral dissolution and precipitation between the calibrated database and the one from the official PHREEQC release demonstrate the necessity of geochemical database calibration for high pH environments. With the calibrated equilibrium constants and kinetic rate constants in the new geochemical database, the sequence of secondary mineral (scale) deposition during ASP flooding as reported in literature can be successfully reproduced. The improved modelling capability for ASP scaling prediction also increases the confidence for other aspects of simulation results such as chemical breakthrough.
Enhanced Oil Recovery by Seawater Flooding in Halfaya Carbonate Reservoir, Iraq: Experiment and Simulation
Authors: Zhu Guangya , Kun Xu Li , Wang Xiaojin , Liu Fang , Cong Yanzi , Zhang Yapu , Ou Jin
Published: March 2016

Seawater flooding has recently been investigated as a new emerging method on improving oil recovery in Middle East carbonates. This paper presents a mechanism study about seawater flooding in carbonates. The objective of this paper is to identify the key controlling factors for improving carbonates oil recovery by seawater injection.

We briefly describe the analytical model for Halfaya (HF) carbonate reservoir. A new parameter is introduced to analyze the salinity affecting on oil recovery. We carry out core flood experiments on selected carbonate core samples and formation water (166840-192450 ppm) from HF carbonates, Iraq. The formation water, seawater and treated seawater with different salinities and ionic compositions are injected to evaluate the effect on oil recovery. The relationship between brine salinity and recovery factor shows that the lower the salinity, the higher the recovery factor, and the optimum salinity (30150 ppm) is much close to that of seawater. Ion composition of seawater is modified to analyze the effects on oil recovery. Ion compositions of both injected and produced water are analyzed. Reservoir simulation predicts the production performance of well group to investigate the improvement of water cut and recovery factor for different kind of injected water.

Results indicate that seawater flooding is feasible for HF carbonate reservoirs. Low salinity of seawater samples with higher SO42- and lower Ca2+ concentration can dramatically improve the oil recovery 5-10%. The mechanism of enhanced oil recovery by seawater is mainly attributed to ion exchange happened during treated seawater flooding in carbonate rocks and the wettability alternation to more water-wet condition.

This study presents a method and parameters to handle core flood data and reservoir simulation results. Furthermore, this paper can be extended to assess other carbonate reservoirs developed by seawater flooding in the Middle East.
Comprehensive Study of Polymer Gel Profile Control for Wag Process in Fractured Reservoir: Using Experimental and Numerical Simulation
Authors: Xiao K. , Mu L. , Wu X. , Yang L. , Xu F. , Zhu G. , Zhu Y.
Published: March 2016

Fracture has a significant impact on sweep efficiency of displacement agent, especially for WAG process. Flooding can be affected negatively by the formation of water and gas channeling. Numerical efforts have been made to improve WAG in fracture reservoirs, however, some deficiencies still exist in understanding behavior of plugging agent and designing injection strategy. This study is conducted to investigate mechanisms of polymer gel injection for profile modification during WAG in fractured reservoirs by core flooding tests and numerical model simulations. Additionally, effect of gel solution on improving sweep efficiency under different WAG parameters is evaluated.

Cores with artificial fractures are applied to flooding experiments using oil, water, CO2 and polymer gel solution. CT image analysis is conducted to evaluate the effect of fracture, WAG and gel injection parameters on performances of sweep efficiency during WAG process. Results of core flooding are matched with numerical simulation model to optimize scheme of gel solution injection.

Core flooding experiments indicate that polymer gel solution in proper composition can control displacement profile effectively by observing CT scan images that can evaluate oil distribution changes quantitatively by image analysis. Additionally, injection strategy of gel profile modification for oil recovery in the period of WAG is optimized by using the core-scale model matched with core flooding, mainly including gel injection volume and timing. Relationship between fracture and injection strategy of WAG and gel is also analyzed. It is shown that WAG ratio of 1:1, small WAG single slug, large volume of gel and early gel injection can provide favorable condition for EOR in reservoir with large fracture. However, considering issues of economy and injection pressure, too large and early gel injection would affect oil production negatively.

The purpose of this study is to provide a much more in-depth and comprehensive understanding of polymer gel control for fractured reservoir during WAG. The idea of method can be an effective guide for enhancing field oil production.
Changes in Spinal Cord Following Inflammatory and Neuropathic Pain and the Effectiveness of Resiniferatoxin
Authors: Abooj Mruvil , Bishnoi Mahendra , Bosgraaf Christine A. , Premkumar Louis S.
Published: March 2016

Peripheral inflammation or nerve injury results in changes in the spinal cord, initiating a process of central sensitization. Although nociceptive Transient Receptor Potential (TRP) channels have been studied extensively, the role of these channels expressed at the central terminals in the spinal cord is not fully understood. Here, we studied the expression and function of TRPV1 channels at the spinal cord following induction of inflammatory pain by Complete Freund's Adjuvant (CFA) and neuropathic pain by Chronic Constriction Injury (CCI). Rats treated with CFA or subjected to CCI developed long-term thermal and mechanical hypersensitivity. Peripheral inflammation or injury induced an inflammatory response at the levels of spinal cord, which included activation of glia and increased levels of proinflammatory mediators. As a result, expression of TRPV1 was significantly increased and the associated function of TRPV1-mediated CGRP release was also significantly increased. Single intrathecal administration of resiniferatoxin (RTX), an ultrapotent TRPV1 agonist, selectively reversed inflammatory thermal hypersensitivity and the associated changes in TRPV1 expression and function without affecting mechanical hypersensitivity. In summary, peripheral nerve activity triggers an inflammatory response at the spinal dorsal horn, which results in enhanced expression and function of TRPV1 channels. Targeting TRPV1 expressed in the central terminals is a viable strategy to alleviate certain modalities of pain.
Effect of Surfactants on Hydrolysis of Mono-N-ethyl-o-toluidine Phosphate
Authors: Yadav Homeshwari , Bhoite S. A. , Singh A. K.
Published: March 2016

Hydrolysis of phosphate ester (Mono-N-ethyl-o-toluidine phosphate) in the presence of different surfactants has been studied at 303 K. The rate of reaction has been found to be first-order and fractional order kinetics with respect to [substrate] and [HCl] respectively. The cationic micelles of cetyltrimethylammonium bromide (CTAB), anionic micelles of sodium dodecyl sulfate (SDS) and nonionic micelles of Brij-35 enhanced the rate of reaction to a maximum value and thereafter, the increase in concentration of surfactant decreased the reaction rate. The rate of reaction increased with increase of dielectric constant of the medium. The variation in the rate of hydrolysis by micelles was treated by considering the Menger-Portnoy, Piszkiewicz's and Berezin kinetic models. The various thermodynamic parameters have also been evaluated. The added salts viz KCl, KNO3, K2SO4 enhanced the rate of reaction in the presence of cationic, anionic and non-ionic micelles. The kinetic parameters i. e. micellar phase (kΨ) and binding constant (KS) were determined from the rate (surfactant) profile.
Thermodynamic Solution Properties of Benzalkonium Chloride in Aqueous and Ethanolic Media and its Interactions with Organized Assemblies of Anionic Surfactant Sodium Dodecyl Sulphate and Amino Acids
Authors: Mahmood Khalid , Shakeel Muhammad , Siddiq Mohammad , Usman Muhammad
Published: March 2016

This manuscript reports the physicochemical behaviour of antimicrobial cationic surfactant benzalkonium chloride (BAC) as well as its interaction with the anionic surfactant sodium dodecyl sulfate in term of mixed micelle. Surface activity of pure BAC was studied by measuring the surface parameters i. e. surface pressure (Π), surface excess concentration (Γ), area per molecule and standard Gibbs free energy of adsorption (ΔGads). The electrical conductivity was measured to calculate the thermodynamic parameters like free energy of micellization, ΔGm, enthalpy of micellization, ΔHm and entropy of micellization, ΔSm. The interaction of the drug with sodium dodecyl sulfate was studied, in term of mixed micelle, by electrical conductivity and UV/Visible spectroscopy. Spectroscopic method helps to calculate the partition coefficient (Kx) and free energy of partition, while the conductivity method is helpful to calculate thermodynamic parameters of their interaction. The effect of different amino acids on CMC of BAC has also been studied.
Influence on rewetting temperature and wetting delay during rewetting rod bundle by various radial jet models
Authors: Debbarma A. , Pandey K. M.
Published: March 2016

Numerical investigation of the rewetting of single sector fuel assembly of Advanced Heavy Water Reactor (AHWR) has been carried out to exhibit the effect of coolant jet diameters (2, 3 and 4 mm) and jet directions (Model: M, X and X2). The rewetting phenomena with various jet models are compared on the basis of rewetting temperature and wetting delay. Temperature-time curve have been evaluated from rods surfaces at different circumference, radial and axial locations of rod bundle. The cooling curve indicated the presence of vapor in respected location, where it prevents the contact between the firm and fluid phases. The peak wall temperature represents as rewetting temperature. The time period observed between initial to rewetting temperature point is wetting delay. It was noted that as improved in various jet models, rewetting temperature and wetting delay reduced, which referred the coolant stipulation in the rod bundle dominant vapor formation.
Stability analysis of the Korean prototype Generation-IV sodium-cooled fast reactor using linear frequency domain approach
Authors: Kim S. J. , Ha P. N. V. , Lim J. Y. , Hahn D. H. , Kang C. M.
Published: March 2016

The Korea Atomic Energy Research Institute (KAERI) has been developing the 150 MWe Prototype Generation-IV Sodium-cooled Fast Reactor (PGSFR). The design concept is highly based on passive safety mechanisms, minimizing the need for engineered safety systems. Presently, it is of primary importance to assure the reactor dynamics and stability against small reactivity disturbances under power operating conditions. KAERI has therefore developed the NuSTAB code for stability analysis of the PGSFR. In NuSTAB, the neutron-kinetic and thermal-hydraulic coupling equations are linearized to form the characteristic equation, which is solved as a generalized eigenvalue problem for determining the decay ratio, an indicator of the system stability. In this paper, the stability of the PGSFR was analyzed by applying the point kinetic and spatial kinetic options in the NuSTAB code. System responses to temperature feedbacks including the Doppler effect, thermal expansion, coolant density change, and overall feedback were studied. The results indicate that the initial U and final TRU cores of the PGSFR are both inherently stable thanks to the temperature feedbacks.
Incorporation of SiC particles in FS welded zone of AZ31 Mg alloy to improve the mechanical properties and corrosion resistance
Authors: Abbasi Mahmoud , Abdollahzadeh Amin , Omidvar Hamid , Bagheri Behrouz , Rezaei Milad
Published: March 2016

The solid-state nature of the friction stir welding (FSW) process leads to several advantages over fusion welding methods as problems associated with cooling from the liquid phase are avoided. This process eliminates many of the defects associated with fusion welding techniques such as shrinkage, solidification cracking and porosity. In general, FSW has been found to produce a low number of defects and is very tolerant of variations in parameters and materials. Nevertheless, physical and chemical properties of the weld zone developed during FSW are a primary concern. In this study, the mechanical properties and corrosion behavior of the weld zone resulting after FSW are investigated and improved by addition of SiC particles. AZ31 magnesium alloy sheets were FS welded and simultaneously processed by incorporation of SiC particles. Mechanical properties and corrosion behavior of FS welded specimens were compared with those of FS welded and processed specimens. The results showed that the addition of SiC particles during FSW considerably improved the mechanical properties and corrosion resistance of the weld zone. Based on the obtained results, incorporation of SiC hard particles in the microstructure of weld zone produced by FSW is highly recommended.
Development and Application of a Scale to Measure Station Design Quality for Personal Safety
Authors: Rahaman Mustafizur , Currie Graham , Muir Carlyn
Published: March 2016

Crime on public transport is a major concern for society and authorities, and many security measures have been adopted in public transport facilities, like stations, to reduce crime and improve the perception of passenger safety. However, a scale to measure the design quality of public transport facilities on the basis of crime prevention through environmental design (CPTED) principles has not yet been developed. This paper presents the results of a research program to develop a unified measure of the overall design quality of train stations in terms of the main elements of CPTED: surveillance, access control or target hardening (deterring access to potential targets; a term used in the security industry), maintenance, territoriality, and activity support. In this study, a scale has been developed and applied to four stations in suburban Melbourne, Victoria, Australia. The scores illustrate the overall station design quality and highlight elements of the stations that could be improved to enhance safety. Areas for future research and implications for practice are explored.
Evaluating Pay-on-Entry Versus Proof-of-Payment Ticketing in Light Rail Transit
Authors: Currie Graham , Reynolds James
Published: March 2016

Pay-on-entry (POE) fare control for on-street transit allows effective revenue protection. However, the POE systems requires single door boarding and therefore increased stop dwell times compared with proof-of-payment (POP) systems. Most light rail transit (LRT) uses POP but is often criticized for poor revenue protection. This paper explores the trade-offs between the POE and POP systems through the comprehensive modeling of revenue protection, dwell time, ridership, revenue, and operational resource impacts in a case study of the conversion of the Melbourne, Victoria, Australia, POP system to a POE system; the paper uses data from LRT in Toronto, Ontario, Canada, which uses a POE system. The results show that the POE system increases journey times (+15%) and decreases ridership (−10%) and that 49 (+14%) additional light rail vehicles are required. POE conversion costs a net 29.4 million Australian dollars (A$) per annum and A$276 million for new vehicles, compared with a fare evasion reduction of A$8.1 million per annum. A 30-year discount cash flow analysis of the POE system results in a benefit–cost ratio of 0.44. The results are most sensitive to POE stop dwell time but not to fare evasion rates. Stop dwell times have a significant impact on LRT financial performance; alternative methods of revenue protection, such as increased inspection rates, are more effective than the POE system. The results justify the widespread adoption of POP systems in LRT and should provide a strong basis for defending against criticisms of the higher fare evasion rates of POP systems. The results should also act as a wake-up call to any LRT (or bus) system that still uses a POE rather than POP system and provide a basis for assessing the impacts of POP conversion for all modes.
Implementing Best-Value Procurement for Design–Bid–Build Highway Projects
Authors: Tran Dai , Molenaar Keith R. , Gransberg Douglas D.
Published: March 2016

State departments of transportation (DOTs) have typically used low-bid procurement to deliver design–bid–build (DBB) highway projects. Although low-bid procurement has provided predictable results for state DOTs, it does not always result in the best performance during and after construction. Thus, state DOTs are increasingly using alternative methods such as best-value procurement to ensure project quality and enhance project performance. In essence, best-value procurement incorporates price with other factors to achieve specific project goals. Compared with low-bid procurement, best-value procurement offers several advantages that can include opportunities to improve project quality, promote innovation, and enhance project performance. To date, with a few exceptions, state DOTs have only used best-value procurement for design–build projects. This study explores the procedures and existing practices for implementing best-value procurement in DBB project delivery. Data were collected from a literature review, a survey questionnaire, and case studies. Three best-value DBB projects from the Michigan, New York State, and Oregon DOTs are presented. The research results showed that the use of best-value procurement for DBB project delivery can provide other benefits to state DOTs besides what was found in the literature, such as emphasizing nonprice factors that align with project objectives, reducing risk, and saving cost.
Comparison of Fatigue Cracking Performance of Asphalt Pavements Predicted by Pavement ME and LVECD Programs
Authors: Wang Yizhuang , Norouzi Amirhossein , Kim Y. Richard
Published: March 2016

Mechanistic–empirical pavement design has received significant attention from the pavement community as the method for designing asphalt pavements in the future. Currently available software for mechanistic–empirical pavement design includes the AASHTOWare Pavement ME Design (Pavement ME) program. The Pavement ME program allows users to predict pavement distresses by applying layered elastic theory for the mechanical responses and using empirical models for the distress predictions. The layered viscoelastic pavement design for critical distresses (LVECD) program, which employs three-dimensional viscoelastic finite element analysis with moving loads, can also be used to predict the fatigue and rutting performance of pavements. The LVECD program employs the simplified viscoelastic continuum damage (S-VECD) model as the material model for the fatigue performance predictions of asphalt mixtures under complex loading and environmental conditions. This paper examines and compares the performance of 33 pavement sections from five research projects located in the United States, Canada, and South Korea by using both the Pavement ME and LVECD computer programs. To verify the results obtained from these two programs, the simulations were compared with the field performance data. In terms of ranking, the LVECD simulations provided better agreement with the field performance data than did the Pavement ME simulations. One of the main reasons for the better predictions obtained by the LVECD program is that its fatigue performance predictions depend on the mixture properties of all the layers, whereas the Pavement ME program considers the fatigue properties of only the bottom layer mixture.
Posthuman Scale
Authors: Thomsen Mads Rosendahl
Published: March 2016

Visions of the posthuman are almost inevitably tied up with questions of scale. The size of Frankenstein's creation sets him apart from humanity, the longevity of Virginia Woolf's Orlando makes her / him uncannily posthuman, and the travels of Gulliver constantly confront the protagonist with the issue of physical scale. This article investigates different dimensions of posthuman scale with examples from fiction, film, and transhumanist writings. From the sizes of bodies and the length of lives to the more complex matters of the scale of consciousness and the magnitude of social connections, what happens when an element of human existence is changed and becomes either very large or very small is a recurrent and important question. Such changes have consequences for ethical dispositions towards the lives of others, for the aesthetic appreciation or dislike of new beings, and for the ability to envision completely new ways of connecting to the world and others, for example through a cloud of shared thoughts, as Olaf Stapledon imagined. One special case of posthuman scale is the replication of the individual and the number of possible lives an individual can live without losing individuality, a question that is also pivotal for the idea of the human as a simulation that has been proposed by writers, filmmakers, and futurists alike.
The Ludic Muse: The Form of Games as Art
Authors: Vella Daniel
Published: March 2016

Taking as its basis Nancy's essay ‘Why Are There Several Arts And Not Just One?’, this paper makes a case for understanding games as constituting art works bearing a specifically ludic form. It draws on aesthetic theory and philosophy – particularly Kant, Heidegger, Gadamer, and Nancy – in order to theorise the particular aesthetic potential inherent to this form, and the challenges it poses to existing concepts of art and aesthetic engagement. The paper will argue that the player's relation to a game, in contrast to the aesthetic relation as theorised in post-Kantian aesthetics, invokes an active, purposive disposition – and, moreover, that it is this active, purposive disposition itself that is brought forth into presentation by the ludic work. The conclusion reached is that the ludic aesthetic work establishes a gameworld as a sphere of existential praxis for the player, within which she lives a being-in-the-gameworld, which, in being inscribed into the unity of the game as an object distinct from the player, is itself externalised as an object of her aesthetic contemplation.
Mind the gap! An exploration of the role of lifelong learning in promoting co-production and citizenship within social care for older people
Authors: Formosa Marvin , Hafford-Letchfield Trish
Published: March 2016

Contemporary themes in public policy have emphasised co-productive approaches within both the access and provision of support services to older people. This paper provides a cross disciplinary exploration from its respective authors perspectives on social work and educational gerontology to examine the potential for lifelong learning and learning interventions from which co-production with those using social care services in later life might be better facilitated. Using an example from the UK, we specifically elicit how co-produced care can enhance the horizon of learning and learning research. The synthesis of ideas across these two disciplines could enrich understanding and provide essential levers for moving towards empowerment and emancipation by engaging with a more co-productive approach in social care for older people.
A Multiple Linear Regression Model for Tropical Cyclone Intensity Estimation from Satellite Infrared Images
Authors: Zhao Yong , Zhao Chaofang , Sun Ruyao , Wang Zhixiong
Published: March 2016

An objectively trained model for tropical cyclone intensity estimation from routine satellite infrared images over the Northwestern Pacific Ocean is presented in this paper. The intensity is correlated to some critical signals extracted from the satellite infrared images, by training the 325 tropical cyclone cases from 1996 to 2007 typhoon seasons. To begin with, deviation angles and radial profiles of infrared images are calculated to extract as much potential predicators for intensity as possible. These predicators are examined strictly and included into (or excluded from) the initial predicator pool for regression manually. Then, the “thinned” potential predicators are regressed to the intensity by performing a stepwise regression procedure, according to their accumulated variance contribution rates to the model. Finally, the regressed model is verified using 52 cases from 2008 to 2009 typhoon seasons. The R2 and Root Mean Square Error are 0.77 and 12.01 knot in the independent validation tests, respectively. Analysis results demonstrate that this model performs well for strong typhoons, but produces relatively large errors for weak tropical cyclones.
Weather and Tourism: Thermal Comfort and Zoological Park Visitor Attendance
Authors: Perkins David , Debbage Keith
Published: March 2016

Weather events have the potential to greatly impact business operations and profitability, especially in outdoor-oriented economic sectors such as Tourism, Recreation, and Leisure (TRL). Although a substantive body of work focuses on the macroscale impacts of climate change, less is known about how daily weather events influence attendance decisions, particularly relating to the physiological thermal comfort levels of each visitor. To address this imbalance, this paper focuses on ambient thermal environments and visitor behavior at the Phoenix and Atlanta zoos. Daily visitor attendances at each zoo from September 2001 to June 2011, were paired with the Physiologically Equivalent Temperature (PET) to help measure the thermal conditions most likely experienced by zoo visitors. PET was calculated using hourly atmospheric variables of temperature, humidity, wind speed, and cloud cover from 7 a.m. to 7 p.m. at each zoological park location and then classified based on thermal comfort categories established by the American Society of Heating and Air Conditioning Engineers (ASHRAE). The major findings suggested that in both Phoenix and Atlanta, optimal thermal regimes for peak attendance occurred within “slightly warm” and “warm” PET-based thermal categories. Additionally, visitors seemed to be averse to the most commonly occurring thermal extreme since visitors appeared to avoid the zoo on excessively hot days in Phoenix and excessively cold days in Atlanta. Finally, changes in the daily weather impacted visitor attendance as both zoos experienced peak attendance on days with dynamic changes in the thermal regimes and depressed attendances on days with stagnant thermal regimes. Building a better understanding of how weather events impact visitor demand can help improve our assessments of the potential impacts future climate change may have on tourism.
Soot Nanoparticles Could Partake in Nucleation of Biogenic Particles in the Atmosphere: Using Fullerene as a Model Compound
Authors: Liu Yiwen , Wang Zhuang , Wang Se , Fang Hao , Wang Degao
Published: March 2016

The detection of existence of fullerenes (C60 and C70) makes it necessary to explore whether soot nanoparticles can participate in new nanometer-sized particle formation and growth in the atmosphere. This study describes a theoretical investigation at multiple levels on the role of the fullerenes (as model compounds to represent nanoparticles of soot) in the formation of complexes with a common atmospheric nucleating precursor (sulfuric acid, SA) and a biogenic organic acid (cis-pinonic acid, CPA), as well as initial growth of nano-sized biogenic aerosols. Quantum chemical density-functional theory calculations identify the formation of stable fullerene-[CPA-SA] ternary complexes, which likely leads to an enhanced nucleation of SA with CPA. Relevant thermochemical parameters including the changes of Gibbs free energy, enthalpy, and entropy for the complex formation also support that fullerene-[CPA-SA] is most likely to be a newly formed nuclei. The sizes of the critical nucleus of the fullerene-[CPA-SA-H2O] systems were found to be approximately 1.3 nm by large-scale molecular dynamics simulations. This study may provide a new insight into the mechanisms underlying the formation of new particle in the atmospheric environment.
Fundamental Features of Quantum Dynamics Studied in Matter-Wave Interferometry—Spin Weak Values and the Quantum Cheshire-Cat
Authors: Sponar Stephan , Denkmayr Tobias , Geppert Hermann , Hasegawa Yuji
Published: March 2016

The validity of quantum-mechanical predictions has been confirmed with a high degree of accuracy in a wide range of experiments. Although the statistics of the outcomes of a measuring apparatus have been studied intensively, little has been explored and is known regarding the accessibility of quantum dynamics. For these sorts of fundamental studies of quantum mechanics, interferometry using neutron matter-waves in particular, provides almost ideal experimental circumstances. In this device quantum interference between spatially separated beams occurs on a macroscopic scale. Recently, the full determination of weak-values of neutrons 1 2 - spin adds a new aspect to the study of quantum dynamics. Moreover, a new counter-intuitive phenomenon, called quantum Cheshire Cat, is observed in an interference experiment. In this article, we present an overview of these experiments.
Mechanisms of Nuclear Export in Cancer and Resistance to Chemotherapy
Authors: El-Tanani Mohamed , Dakir El-Habib , Raynor Bethany , Morgan Richard
Published: March 2016

Tumour suppressor proteins, such as p53, BRCA1, and ABC, play key roles in preventing the development of a malignant phenotype, but those that function as transcriptional regulators need to enter the nucleus in order to function. The export of proteins between the nucleus and cytoplasm is complex. It occurs through nuclear pores and exported proteins need a nuclear export signal (NES) to bind to nuclear exportin proteins, including CRM1 (Chromosomal Region Maintenance protein 1), and the energy for this process is provided by the RanGTP/RanGDP gradient. Due to the loss of DNA repair and cell cycle checkpoints, drug resistance is a major problem in cancer treatment, and often an initially successful treatment will fail due to the development of resistance. An important mechanism underlying resistance is nuclear export, and a number of strategies that can prevent nuclear export may reverse resistance. Examples include inhibitors of CRM1, antibodies to the nuclear export signal, and alteration of nuclear pore structure. Each of these are considered in this review.
Low-Temperature Oxidation of Dimethyl Ether to Polyoxymethylene Dimethyl Ethers over CNT-Supported Rhenium Catalyst
Authors: Zhang Qingde , Wang Wenfeng , Zhang Zhenzhou , Han Yizhuo , Tan Yisheng
Published: March 2016

Due to its excellent conductivity, good thermal stability and large specific surface area, carbon nano-tubes (CNTs) were selected as support to prepare a Re-based catalyst for dimethyl ether (DME) direct oxidation to polyoxymethylene dimethyl ethers (DMMx). The catalyst performance was tested in a continuous flow type fixed-bed reactor. H3PW12O40 (PW12) was used to modify Re/CNTs to improve its activity and selectivity. The effects of PW12 content, reaction temperature, gas hourly space velocity (GHSV) and reaction time on DME oxidation to DMMx were investigated. The results showed that modification of CNT-supported Re with 30% PW12 significantly increased the selectivity of DMM and DMM2 up to 59.0% from 6.6% with a DME conversion of 8.9%; besides that, there was no COx production observed in the reaction under the optimum conditions of 513 K and 1800 h−1. The techniques of XRD, BET, NH3-TPD, H2-TPR, XPS, TEM and SEM were used to characterize the structure, surface properties and morphology of the catalysts. The optimum amount of weak acid sites and redox sites promotes the synthesis of DMM and DMM2 from DME direct oxidation.
Prader-Willi Syndrome: The Disease that Opened up Epigenomic-Based Preemptive Medicine
Authors: Kubota Takeo , Miyake Kunio , Hariya Natsuyo , Tran Nguyen Quoc Vuong , Mochizuki Kazuki
Published: March 2016

Prader-Willi syndrome (PWS) is a congenital neurodevelopmental disorder caused by loss of function of paternally expressed genes on chromosome 15 due to paternal deletion of 15q11–q13, maternal uniparental disomy for chromosome 15, or an imprinting mutation. We previously developed a DNA methylation-based PCR assay to identify each of these three genetic causes of PWS. The assay enables straightforward and rapid diagnosis during infancy and therefore allows early intervention such as nutritional management, physical therapy, or growth hormone treatment to prevent PWS patients from complications such as obesity and type 2 diabetes. It is known that various environmental factors induce epigenomic changes during the perinatal period, which increase the risk of adult diseases such as type 2 diabetes and intellectual disabilities. Therefore, a similar preemptive approach as used in PWS would also be applicable to acquired disorders and would make use of environmentally-introduced “epigenomic signatures” to aid development of early intervention strategies that take advantage of “epigenomic reversibility”.
Selected Remarks about Computer Processing in Terms of Flow Control and Statistical Mechanics
Authors: Strzałka Dominik
Published: March 2016

Despite the fact that much has been said about processing in computer science, it seems that there is still much to do. A classical approach assumes that the computations done by computers are a kind of mathematical operation (calculations of functions values) and have no special relations to energy transformation and flow. However, there is a possibility to get a new view on selected topics, and as a special case, the sorting problem is presented; we know many different sorting algorithms, including those that have complexity equal to O(n lg(n)) , which means that this problem is algorithmically closed, but it is also possible to focus on the problem of sorting in terms of flow control, entropy and statistical mechanics. This is done in relation to the existing definitions of sorting, connections between sorting and ordering and some important aspects of computer processing understood as a flow that are not taken into account in many theoretical considerations in computer science. The proposed new view is an attempt to change the paradigm in the description of algorithms’ performance by computational complexity and processing, taking into account the existing references between the idea of Turing machines and their physical implementations. This proposal can be expressed as a physics of computer processing; a reference point to further analysis of algorithmic and interactive processing in computer systems.
The Evolving Transmission of Uncertainty Shocks in the United Kingdom
Authors: Mumtaz Haroon
Published: March 2016

This paper investigates if the impact of uncertainty shocks on the U.K. economy has changed over time. To this end, we propose an extended time-varying VAR model that simultaneously allows the estimation of a measure of uncertainty and its time-varying impact on key macroeconomic and financial variables. We find that the impact of uncertainty shocks on these variables has declined over time. The timing of the change coincides with the introduction of inflation targeting in the U.K.
Shape Design of the Duct for Tidal Converters Using Both Numerical and Experimental Approaches (pre-2015)
Authors: Jo Chul , Kim Do , Hwang Su , Goo Chan
Published: March 2016

Recently, focus has been placed on ocean energy resources because environmental concerns regarding the exploitation of hydrocarbons are increasing. Among the various ocean energy sources, tidal current power (TCP) is recognized as the most promising energy source in terms of predictability and reliability. The enormous energy potential in TCP fields has been exploited by installing TCP systems. The flow velocity is the most important factor for power estimation of a tidal current power system. The kinetic energy of the flow is proportional to the cube of the flow’s velocity, and velocity is a critical variable in the performance of the system. Since the duct can accelerate the flow velocity, its use could expand the applicable areas of tidal devices to relatively low velocity sites. The inclined angle of the duct and the shapes of inlet and outlet affect the acceleration rates of the flow inside the duct. In addition, the volume of the duct can affect the flow velocity amplification performance. To investigate the effects of parameters that increase the flow velocity, a series of simulations are performed using the commercial computational fluid dynamics (CFD) code ANSYS-CFX. Experimental investigations were conducted using a circulation water channel (CWC).
Phenol-Formaldehyde Resin-Based Carbons for CO2 Separation at Sub-Atmospheric Pressures
Authors: Álvarez-Gutiérrez Noelia , Gil María , Martínez María , Rubiera Fernando , Pevida Covadonga
Published: March 2016

The challenge of developing effective separation and purification technologies that leave much smaller energy footprints is greater for carbon dioxide (CO2) than for other gases. In addition to its involvement in climate change, CO2 is present as an impurity in biogas and bio-hydrogen (biological production by dark fermentation), in post-combustion processes (flue gas, CO2-N2) and many other gas streams. Selected phenol-formaldehyde resin-based activated carbons prepared in our laboratory have been evaluated under static conditions (adsorption isotherms) as potential adsorbents for CO2 separation at sub-atmospheric pressures, i.e., in post-combustion processes or from biogas and bio-hydrogen streams. CO2, H2, N2, and CH4 adsorption isotherms at 25 °C and up to 100 kPa were obtained using a volumetric equipment and were correlated by applying the Sips model. Adsorption equilibrium was then predicted for multicomponent gas mixtures by extending the multicomponent Sips model and the Ideal Adsorbed Solution Theory (IAST) in conjunction with the Sips model. The CO2 uptakes of the resin-derived carbons from CO2-CH4, CO2-H2, and CO2-N2 at atmospheric pressure were greater than those of the reference commercial carbon (Calgon BPL). The performance of the resin-derived carbons in terms of equilibrium of adsorption seems therefore relevant to CO2 separation in post-combustion (flue gas, CO2-N2) and in hydrogen fermentation (CO2-H2, CO2-CH4).
Climate Change and Increased Irrigation Demands: What Is Left for Hydropower Generation? Results from Two Semi-Arid Basins
Authors: Bakken Tor , Almestad Christian , Melhuus Rugelbak Jørgen , Escobar Marisa , Micko Steven , Alfredsen Knut
Published: March 2016

In this study, we have modelled the effect of climate change and increased irrigation withdrawals on the available water for hydropower production in two semi-arid river basins, i.e., Kizilirmak (Turkey) and Devoll (Albania), and the role of the reservoirs. The combined effect of climate change and extended irrigation withdrawals will overall lead to reduced runoff in the rivers, according to our simulations. The changes will be most dramatic at Kizilirmak, reducing the water available for hydropower production. The presence of the reservoirs will lead to extended water use/losses due to the provision of regulated flow, enabling larger irrigation withdrawals and increasing the evaporative losses from the reservoir surfaces. Comparing the water consumption losses at Kizilirmak, the irrigation losses are in the range of 2–4 times larger than the gross evaporation losses from reservoir surfaces. The reservoirs at Devoll will improve water availability for hydropower production during low flow periods, and the upstream irrigation represents presently a low risk to the downstream power producers. As the results are sensitive to specific river basin characteristics and the assumptions made, the results cannot be generalized to other river basins without taking these specifics into consideration.
Enhancement of Fire Safety of an Existing Green Building due to Natural Ventilation
Authors: Huang Hong , Su Chung , Li Cheng , Lin Ching , Lin Chun
Published: March 2016

In recent years, natural ventilation technology is extensively used in order to improve indoor environment quality and reduce power consumption of air-conditioning systems in green buildings. However, the effect of natural ventilation on fires needs to be evaluated carefully, and how to make these energy-saving buildings safe is a topic worth studying. This study uses Fire Dynamics Simulator on some fire safety enhancement measures for an existing green building without installation of a smoke exhaust system. Since the building is located on a school campus, it does not require a smoke exhaust system according to Taiwan fire regulations. Referential results, obtained after a series of improvement strategies are tested, show that kiln natural ventilation can generate a comfortable air flow. Unfortunately, due to the stack effect, hot air and fatal smoke are blown into the evacuation route area behind the room when a fire occurs. The findings showed that there are two feasible improvement measures, “controlling the off state of each air inlet” and “setting up an exhaust port in the rear of room”, which can effectively resolve the fire safety issues; the construction of which can be undertaken at a reasonable cost.
On Scalability and Replicability of Smart Grid Projects—A Case Study
Authors: Sigrist Lukas , May Kristof , Morch Andrei , Verboven Peter , Vingerhoets Pieter , Rouco Luis
Published: March 2016

This paper studies the scalability and replicability of smart grid projects. Currently, most smart grid projects are still in the R&D or demonstration phases. The full roll-out of the tested solutions requires a suitable degree of scalability and replicability to prevent project demonstrators from remaining local experimental exercises. Scalability and replicability are the preliminary requisites to perform scaling-up and replication successfully; therefore, scalability and replicability allow for or at least reduce barriers for the growth and reuse of the results of project demonstrators. The paper proposes factors that influence and condition a project’s scalability and replicability. These factors involve technical, economic, regulatory and stakeholder acceptance related aspects, and they describe requirements for scalability and replicability. In order to assess and evaluate the identified scalability and replicability factors, data has been collected from European and national smart grid projects by means of a survey, reflecting the projects’ view and results. The evaluation of the factors allows quantifying the status quo of on-going projects with respect to the scalability and replicability, i.e., they provide a feedback on to what extent projects take into account these factors and on whether the projects’ results and solutions are actually scalable and replicable.
Improving the Eco-Efficiency of High Performance Computing Clusters Using EECluster
Authors: Cocaña-Fernández Alberto , Sánchez Luciano , Ranilla José
Published: March 2016

As data and supercomputing centres increase their performance to improve service quality and target more ambitious challenges every day, their carbon footprint also continues to grow, and has already reached the magnitude of the aviation industry. Also, high power consumptions are building up to a remarkable bottleneck for the expansion of these infrastructures in economic terms due to the unavailability of sufficient energy sources. A substantial part of the problem is caused by current energy consumptions of High Performance Computing (HPC) clusters. To alleviate this situation, we present in this work EECluster, a tool that integrates with multiple open-source Resource Management Systems to significantly reduce the carbon footprint of clusters by improving their energy efficiency. EECluster implements a dynamic power management mechanism based on Computational Intelligence techniques by learning a set of rules through multi-criteria evolutionary algorithms. This approach enables cluster operators to find the optimal balance between a reduction in the cluster energy consumptions, service quality, and number of reconfigurations. Experimental studies using both synthetic and actual workloads from a real world cluster support the adoption of this tool to reduce the carbon footprint of HPC clusters.