bluuebunny/crossref_metadata_2025 huggingface dataset:
Joint analysis of simultaneous EEG and eye tracking data for video images
Authors: Szajerman Dominik , Napieralski Piotr , Lecointe Jean-Philippe
Published: October 2018

Purpose

Technological innovation has made it possible to review how a film cues particular reactions on the part of the viewers. The purpose of this paper is to capture and interpret visual perception and attention by the simultaneous use of eye tracking and electroencephalography (EEG) technologies.

Design/methodology/approach

The authors have developed a method for joint analysis of EEG and eye tracking. To achieve this goal, an algorithm was implemented to capture and interpret visual perception and attention by the simultaneous use of eye tracking and EEG technologies. All parameters have been measured as a function of the relationship between the tested signals, which, in turn, allowed for a more accurate validation of hypotheses by appropriately selected calculations.

Findings

The results of this study revealed a coherence between EEG and eye tracking that are of particular relevance for human perception.

Practical implications

This paper endeavors both to capture and interpret visual perception and attention by the simultaneous use of eye tracking and EEG technologies. Eye tracking provides a powerful real-time measure of viewer region of interest. EEG technologies provides data regarding the viewer’s emotional states while watching the movie.

Originality/value

The approach in this paper is distinct from similar studies because it takes into account the integration of the eye tracking and EEG technologies. This paper provides a method for determining a fully functional video introspection system.
Levels and interconnections of project success in development projects by Non-Governmental Organisations (NGOs)
Authors: Nanthagopan Yogarajah , Williams Nigel , Thompson Karen
Published: October 2018

Purpose

The purpose of this paper is to understand and identify the nature of evaluation criteria, levels and associations among levels of project success in development projects by NGOs in Sri Lanka.

Design/methodology/approach

The setting for this study is Sri Lanka, a country currently recovering from civil war and natural disasters and host to a large number of national and international NGOs involved in development projects. Data collection was conducted using a quantitative survey which obtained 447 responses. Multivariate analysis of data was conducted using confirmatory factor analysis and structural equation modelling.

Findings

The study confirmed that overall project success in NGOs could be assessed in three levels: project management (PM) success, project success and NGO success. The results conclude that there are strong associations among the three levels of project success; moreover, PM success and project success are indispensable for achieving NGO success.

Originality/value

This study extends existing research to confirm the presence of the three levels of project success and the interconnections among them. These findings can support subsequent research on development projects and also support the design of holistic evaluation tools to support project practices in NGOs.
Personality traits and expatriate adjustment in Malaysia
Authors: Richardson Christopher , Tan Guat-Hoon , Kiumarsi Shaian
Published: October 2018

Purpose

This paper aims to investigate and reflect upon the effects of personality traits on expatriate adjustment within the context of Malaysia’s multicultural society.

Design/methodology/approach

Drawing on the multicultural personality questionnaire (MPQ) and extrapolating from the literature on expatriate adjustment, the authors introduce five hypotheses, which are then tested based on data derived from 101 expatriates working in Malaysia.

Findings

The results indicate a positive relationship between both open-mindedness and adjustment as well as between flexibility and adjustment. However, the authors did not observe any significant positive relationship between the three remaining MPQ personality traits and expatriate adjustment.

Originality/value

While various studies have investigated the relationship between personality and expatriate adjustment in an Asian context, the majority have been conducted in largely monocultural settings, or at least on the implicit assumption of a single societal culture within the host country. This paper contributes to the literature by exploring the relationship in the context of a multicultural Asian host country.
Contextual variability in biopsychosocial pathways to violent offending
Authors: Fenimore Danielle M. , Jennings Wesley G.
Published: October 2018

Purpose

The purpose of this paper is to use data from the Longitudinal Study of Violent Criminal Behavior in the USA to examine case configurations of violent behavior using a biopsychosocial framework. Specifically, the theory posits that arguably all behavior is the result of specific combinations of biopsychological (individual) and sociocultural (environmental) characteristics that are interacting within the individual. With regard to criminal and violent behavior, the theoretical assumption is that this maladaptive behavior is the result of a negative interaction between the biopsychological and sociocultural factors.

Design/methodology/approach

The study design consists of secondary data analysis. A conjunctive analysis of case configurations was performed using data from the Longitudinal Survey of Violent Criminal Behavior to formally explore the tenets of Cortés and Gatti’s (1972) biopsychosocial theory.

Findings

The results suggest that there are main effects for ego strength, family problems, family incohesiveness and underachievement as they relate to offending. A possible six-way interaction was also identified within the case configurations that provides empirical support for Cortés and Gatti’s (1972) biopsychosocial theory of deviance.

Originality/value

The present study contributes to the existing biopsychosocial literature by providing insight on the contextual variability in pathways to violent offending. Specifically, the evidence provided indicates that Cortés and Gatti’s (1972) biopsychosocial theory of deviance can be extended to comparing violent and non-violent offenders. Implications for policy and practice are also discussed.
Treatment of psychopathy: a conceptual and empirical review
Authors: Lewis Michael
Published: October 2018

Purpose

For decades, psychopathy has been thought to be untreatable. Yet, conceptualisations, and indeed its assessment, have deviated away from viewing the disorder as personality pathology towards a behavioural focus where the core underlying deficits in cognition and affect have been ignored. Interventions have followed suit leading to a premature discounting of the role of therapy in adjusting psychopathic traits. The paper aims to discuss these issues.

Design/methodology/approach

The review critically evaluates the conceptual and empirical evidence relevant to the treatment of psychopathy, deciphering components integral to the disorder that require intervention. Psychopathy is approached from a developmental perspective, with the review identifying several mechanisms thought to be responsible for precipitating and perpetuating its expression.

Findings

There appears some utility in targeting psychopathy from multiple angles, addressing experiences of trauma, associated schemas and the underlying cognitive-affective dysfunction noted to give rise to psychopathic traits. A new model for treatment was proposed integrating these factors to encourage the design of effective interventions that will address the origins and underlying deficits of the disorder, rather than symptomology.

Originality/value

The review encourages future research to consider the aetiology of psychopathy, with the aim of informing early intervention and containing the disorder whilst in its infancy, as well as addressing neurobiological dysfunction when most malleable.
Productivity gains through standardization-of-work in a manufacturing company
Authors: Mor Rahul S. , Bhardwaj Arvind , Singh Sarbjit , Sachdeva Anish
Published: October 2018

Purpose

The purpose of this paper is to identify the non-value-adding activities (NVAs) of core making process and to eliminate them through the standardization-of-work (SW) procedures in a manufacturing company.

Design/methodology/approach

The action-research methodology was adopted for the current study. First, various lean tools were identified through literature review, and the bottleneck area was identified in discussion with the shop-floor executives. NVAs were recorded after a continuous process study including method study and motion analysis followed by the standard operating procedure. Second, the standardized work combination tables were prepared and NVAs were eliminated using the SW procedures. SW has been opted because it is a set of actions which helps in analyzing, improving and controlling the process and it leads to continual improvement.

Findings

The production logbook revealed that the capacity in this particular workstation was 54 pieces per 7 h work shift against the current production of approx. 45–50 pieces (past data). SW saved 31.6 s per cycle which boosted the production up to 58 pieces per 7 h work shift. Finally, the authors came to know that the productivity of this particular process increased up to 6.5 percent which may upsurge if this action is executed continually with the support from shop-floor executives and management. These results were also compared with previous research works in this area and found significant relevance, and hence, the results appear to be reliable.

Research limitations/implications

This is a unique study in itself which explores the lean model by assessing NVAs of core making process. The proposed approach needs to be tested across different other core making processes of the case company so as to generalize the effectiveness of SW as well as the results obtained in the current study.

Practical implications

The current study illustrates an important step to give more visibility to the lean concept by addressing the problem of lack of standard procedures. This study will help the shop-floor executives and managers to focus their efforts in achieving high performance through effective implementation of SW. The study should be of the interest of researchers in the area of lean manufacturing, operations management, productivity analysis, etc.

Originality/value

The findings of this study are based on the problem formulation for productivity gains using SW procedures in the case company. The study introduces a new perspective for the execution of SW for core making processes. SW created transparency in workflow, enhanced the safety and eliminated the 3Ms. The outcome of the current study was discussed with the production team and management of the company to validate the productivity gains and received an optimistic response. Most importantly, these improvements were achieved with no investment in machinery or tooling.
Why did I buy this?
Authors: Jacobsen Stephanie
Published: October 2018

Purpose

This paper aims to develop a link between word-of-mouth and attribution of credit or blame following a purchase. Attribution is important because it can affect repurchase behavior, loyalty and word-of-mouth; therefore, understanding who receives credit or blame for a purchase outcome following a product recommendation is critical.

Design/methodology/approach

Through three studies, how recommendation context affects attribution of credit or blame to consumers, reviewers and retailers is experimentally examined. These studies test the thesis that context factors that are independent of the product recommendation can affect how consumers assign responsibility for the product’s performance.

Findings

Results demonstrate that while consumers trust online reviews, the addition of reviewer incentives diminish that trust, especially when a consumer identifies with the retailer. Findings show support for retailers using online reviews and provide evidence for using caution when incentivizing reviewers.

Research limitations/implications

This study makes a theoretical connection between word-of-mouth (reviews) and attribution. As this connection is not seen often in the literature, future research should look at the role the recommender plays in the purchasing process. This study forced participants to attribute a purchase success/failure to certain parties to find a baseline with which to begin. Future studies should look at this process as more spontaneous. It may not always occur or possibly only occur for certain types of purchases or experiences.

Practical implications

Retailers should be continuing to use online reviews as they provide protection from blame and an increase in credit for successful outcomes. This study also provides evidence that incorporating social media into online reviews as many sites have been doing may actually backfire. While it might be more helpful to the consumer, it can increase blame to the retailer. Reviewers are receiving incentives more frequently, and this study finds that loyal consumers should not be shown incentivized reviews as it heightens blame after a negative outcome.

Social implications

While attribution has been found to be an important part of the purchasing process, it has not been looked at in relationship to word-of-mouth/electronic word-of-mouth (offline/online reviews). Knowing that who recommends a product to us impacts post-purchase behavior is important, as online reviews are utilized more frequently. Many social media strategies have been implemented without information as to how the retailer themselves will be impacted. This study provides evidence of how to better utilize online reviews.

Originality/value

Though online reviews have been studied widely, less is known about how reviews and product recommendations affect attribution of credit or blame for a post-purchase outcome. The theoretical link between word-of-mouth and product outcome attribution provided here will help guide future research in this area.
Barriers and solutions to assessing digital library reuse: preliminary findings
Authors: O’Gara Genya Morgan , Woolcott Liz , Joan Kelly Elizabeth , Muglia Caroline , Stein Ayla , Thompson Santi
Published: October 2018

Purpose

The purpose of this paper is to highlight the initial top-level findings of a year-long comprehensive needs assessment, conducted with the digital library community, to reveal reuse assessment practices and requirements for digital assets held by cultural heritage and research organizations. The type of assessment examined is in contrast to traditional library analytics, and does not focus on access statistics, but rather on how users utilize and transform unique materials from digital collections.

Design/methodology/approach

This paper takes a variety of investigative approaches to explore the current landscape, and future needs, of digital library reuse assessment. This includes the development and analysis of pre- and post-study surveys, in-person and virtual focus group sessions, a literature review, and the incorporation of community and advisory board feedback.

Findings

The digital library community is searching for ways to better understand how materials are reused and repurposed. This paper shares the initial quantitative and qualitative analysis and results of a community needs assessment conducted in 2017 and 2018 that illuminates the current and hoped for landscape of digital library reuse assessment, its strengths, weaknesses and community applications.

Originality/value

In so far as the authors are aware, this is the first paper to examine with a broad lens the reuse assessment needs of the digital library community. The preliminary analysis and initial findings have not been previously published.
Biodiesel fuel blend performance evaluation using a radial finned tube heater
Authors: Wijayanto Danar Susilo , Pambudi Nugroho Agung , Wijaya Yusuf , Rohman Ngatou , Bugis Husin
Published: October 2018

Purpose

The purpose of this paper is to experimentally investigate the effect of biodiesel fuel blending and heating on engine torque and power.

Design/methodology/approach

To obtain torque and power data, a 1200 AWD dynamometer was used. The 1200 AWD dynamometer is a device used to obtain readings, and is made up of a chassis, inertia roller, roller sensor and converter modules, and can also be connected to a personal computer.

Findings

The result revealed that biodiesel blending and heating significantly affected torque and power. When only biodiesel blend ratio was varied, the highest torque and power were obtained at 30 per cent fuel blending. Also, the highest torque and power were obtained at 20 mm when only a spaced finned tube heater was used. When both variables were combined, the highest torque was obtained at a 20 per cent biodiesel blend and a 10 mm radial radiator finned spacing. Maximum power for two variables was obtained at the 20 per cent blend ratio and 20 mm finned tube heater spacing.

Originality/value

A novel radial finned tube heater is used.
Development of a Novel Solar Photoelectrochemical Tandem Reactor With a Perforated Photocathode for Simultaneous Hydrogen Production and Waste Water Treatment
Authors: Wullenkord Michael , Jung Christian , Smirnova Olena , Sattler Christian
Published: October 2018

Hydrogen generation in solar photoelectrochemical reactors could provide an important contribution to future energy regimes by storing intermittent renewable energy in a versatile energy vector. Using waste water as electron donor potentially facilitates economic operation. Here, organic contaminants instead of water are oxidised at the anode and two products of value are obtained simultaneously: hydrogen and clean water. Three different reactor concepts were compared in terms of ohmic losses. Based on the results of the simplified analysis a novel planar and scalable solar reactor with an aperture area of 368 cm2 was developed. It features a perforated photocathode and a non-perforated photoanode, both cold gas sprayed, in tandem arrangement and accepts electrolyte temperatures of up to 80°C. Confirmed by ray-tracing simulations the slit design of the photocathode allows homogeneous illumination of the two involved photoelectrodes with DLR’s test platform SoCRatus (Solar Concentrator with a Rectangular Flat Focus). The photocathode compartment and the photoanode compartment are separated by a membrane. Thus, the membrane being located in the optical path has to show sufficiently high transparency for solar light, particularly in the UV-Vis range. A 1,418 h aging study was performed in order to assess the optical performance of a Nafion™ membrane N1110 exposed to an aqueous mixture at 80°C, which contained 10 vol.-% methanol as a model substance for organic contaminants and sulfuric acid to adjust pH 3. It could be verified that the membrane maintains high transparency in the considered wavelength region from 280 nm to 1,100 nm which suggests the feasibility of the reactor concept. The design electrolyte flow of 2.5 l/min through each of the two reactor chambers practically allows isothermal operation on the SoCRatus under 17.5-fold concentrated irradiation. The inlet and outlet geometry of the reactor aims at uniform flow patterns, a low pressure drop as well as effective product gas transport and was optimised for automatic manufacturing. Reference electrodes and temperature sensors are incorporated directly in the reactor body for extended analysis and operation options. The parts of the reactor ensure compatibility with a wide range of waste waters and involved chemicals as well as mechanical stability. Moreover, they are resistant to light exposure and weathering.
Comparison of Different Energy Storage Systems for a Small Airport Facility
Authors: Shafiee Shahin , McCay Mary Helen
Published: October 2018

Airports, one of the important transportation components in this modern age, are under continuous improvement especially in regard to energy sustainability. While most work is concentrated on large airports, smaller airports which are mostly scattered around rural areas seem to be better opportunities for renewable energy utilization. However, while renewable energy has come into use at airports over the past decade, it has been at a slow pace and has not included storage. A reliable storage system can significantly increase the power reliability of a small airport and make a renewable energy system viable.

Acquiring the technical requirements of a facility based on its characteristics enables the designer to evaluate the power source options and develop an efficient storage system. The current paper analytically develops a framework to design and integrate an energy storage method for a renewable system into a small airport facility. The framework details include methods for energy storage which are environmentally acceptable in combination with renewable energy sources to produce electrical power for the on-site facilities. The technical analysis which leads to the sizing of the storage unit initiates with categorizing different methods for energy storage and their applicability to an airport facility for off-grid and on-grid modes.

Based on the results and conclusions from the first step, the search is narrowed down to mediums for electricity storage for a wind farm or solar power plant. In such a case, the main applications of the storage unit could be either to supply power to the facility during the transition time from the renewable source to the main grid or to regulate the power frequency of the generation unit. Capacitors and batteries were selected as the two options for the given power requirement of the facility. Considering the wide variety of available technologies and lower costs, the appropriate storage system is proposed for both long term and short term applications. A table is presented to compare available battery technologies and their respective storage capacities.
Electrochemical Energy Storage and Synthetic Natural Gas Production Based on Reversible Molten Carbonate Cells
Authors: Mastropasqua Luca , Baia Francesca , Conti Luca , Campanari Stefano
Published: October 2018

One of the biggest issues associated to Carbon Capture and Utilisation (CCU) applications involves the exploitation of the captured CO2 as a valuable consumable. An interesting application is the conversion of CO2 into renewable fuels via electrochemical reduction at high temperature. Still unexplored in the literature is the possibility of employing a Molten Carbonate Electrolysis Cell (MCEC) to directly converting CO2 and H2O into H2, CO and eventually CH4, if a methanation process is envisaged. The introduction of this concept into a reversible system — similarly to the process proposed with reversible solid-oxide cells — allows the creation of a cycle which oxidises natural gas to produce CO2 and then employs the same CO2 and excess renewable energy to produce renewable natural gas. The result is a system able to perform electrochemical storage of excess renewable energy (from wind or solar) and if/when required sell renewable natural gas to the grid.

In this work, a simulation of a reversible Molten Carbonate Cell (rMCC) is proposed. The reference MCFC technology considered is that from FuelCell Energy (USA) whose smaller stack is rated at 375 kW (DC). A simplified 0D stack model is developed and calibrated against experimental data. The Balance of Plant (BoP) is in common between the two operation modes MCFC and MCEC. In the former case, natural gas is electrochemically oxidised in the fuel compartment which receives carbonate ions (CO32−) from the air compartment, fed with air enriched with CO2 produced during electrolysis mode. The CO2 in the anode off gas stream is then purified and stored. In electrolysis mode, the stored CO2 is mixed with process H2O and sent to the fuel compartment of the MCEC; here, electrolysis and internal methanation occur. An external chemical reactor finalises the production of methane for either natural gas grid injection or storage and reuse in fuel cell mode. A thermodynamic analysis of the system is performed the yearly round-trip efficiency is assessed considering an assumed availability operating time of 7000 h/y. Finally, the overall green-house gas emission is assessed.
Gradient Based Soil Thermal Conductivity Optimization for Ground Source Heat Exchangers
Authors: DiCarlo Anthony A. , Caldwell Rickey A.
Published: October 2018

In geothermal heating and cooling, there exists an opportunity to improve the efficiency by utilizing non-uniform soil properties of a ground source heat exchanger during installation. This paper presents a gradient approach based upon finite element mathematics to determine an optimal distribution of heterogeneous soils with varying thermal conductivities. The numerically simulated case studies demonstrate the good performance of this algorithm to minimize the cross-talk of heat flux between pipes and maximize the overall efficiency.
The Potential for Integrating Solar Thermal Energy in Both Centralized and Decentralized Systems in Egypt
Authors: Imam Ramy , Yassin Mohamed
Published: October 2018

There is an increasing need for the integration of renewable energy into the energy sector in Egypt. As the electricity subsidies are residing for consumers in Egypt, electricity prices are increasing. This increase in energy prices can be mitigated by the integration of renewable energy technologies. One of the most promising renewable energy technologies that will help stabilize the energy situation in Egypt, is Solar Thermal Energy. Solar Thermal Energy has a great potential in Egypt due to the availability and intensity of direct irradiance in Egypt. Therefore, Egypt has an amazing opportunity as a developing country to start perusing solar thermal technologies; these technologies include decentralized and centralized technologies. Decentralized technologies are targeted more for regular consumers and centralized technologies are targeted more for power generation and industries.
Design Using Ray Tracing for a Solar Chemistry Test Module
Authors: Nguyen Clayton , Shen Lu , Jeter Sheldon , Loutzenhiser Peter
Published: October 2018

Development is underway for modifications to an existing central receiver power tower concentrator solar power research facility to accommodate a new solar chemical test module. Optical analysis, using Sol Trace, is done to model the existing heliostat field, general tower geometry, and planned system layout to predict the incident irradiation to the new experimental receiver called the Solar Reducer Receiver Reactor (SR3). Within the SR3, a layer of particles flowing over an inclined plane will be highly irradiated to chemically reduce the particulate. To accommodate the inclined plane reactor geometry, a beam down mirror will be modeled. An estimated 1000 suns will be required at the aperture. Currently, the field typically provides around 300 suns over a 1 m × 1 m area. To achieve the required higher flux, a secondary concentrator will concentrate the irradiation from a larger area into a smaller focal spot. Rather than using an expensive compound parabolic design, a series of flat plate petals will instead be used to create a cost effective secondary. The flat plate design also provides added benefits for ease of installation, manufacturing, and cooling. The ray tracing model is used to compare several design parameters including the number of petals, petal length, aperture size and the inclination angle of the petals for the secondary.

With these parameters selected, designs have been created for a test module to be constructed at King Saud University’s Riyadh Techno Valley CSP Tower. Additionally, the model is used to estimate the necessary cooling needed to operate both the secondary concentrator and the beam down mirror. These models will be tested experimentally using several quartz heaters. The beam down will be cooled by forced convection air, while the secondary concentrator will use water cooling. Lab experiments will measure the feasibility and effectiveness of the proposed cooling before construction. Once these proof of concepts tests have been completed, construction of the secondary concentrator and beam down mirror will begin to allow for testing in 2018.
Autothermal Operation of a Biomass Torrefaction Plant
Authors: Haseli Yousef
Published: October 2018

Biomass torrefaction is a thermal pretreatment which takes place at a temperature between 200–300 °C in a non-oxidative environment. The process requires thermal energy for drying and torrefying the raw biomass. The amount of the required heat may vary depending on the biomass moisture content, operating temperature and residence time. The volatiles released during the torrefaction are usually burnt in a combustor to meet the heat requirement of the process. If the energy content of the volatiles is less than the thermal energy required for the process, the operation of the torrefaction unit is below the autothermal mode so an auxiliary fuel such as natural gas is burnt together with the volatiles.

This paper investigates autothermal operation of a torrefaction unit which consists of a dryer, a torrefaction reactor, a combustor, and two heat exchangers. An experimentally validated process model is employed to identify a relation between the moisture content, torrefaction temperature, and residence time at autothermal operation. The model is capable of predicting the composition of volatiles and torrefied biomass, mass and energy yields, process heat requirement, and CO2 emissions. The results are graphically presented allowing one to determine whether a torrefaction unit operates below or above the autothermal mode at given torrefaction temperature, residence time and moisture content. Furthermore, the effect of the main operating parameters on the carbon dioxide emissions of the torrefaction unit is discussed.
Sustainable Alkaline Membrane Fuel Cell (SAMFC)
Authors: Raimundo Rodrigo C. , Vargas José V. C. , Balmant Wellington , Ordóñez Juan C.
Published: October 2018

This work addresses the development and construction of a sustainable alkaline membrane fuel cell (SAMFC). The SAMFC couples an alkaline membrane fuel cell (AMFC) with a hydrogen generation reactor that uses recycled aluminum from soda cans to split the water molecule through the oxidation of aluminum catalyzed by sodium hydroxide. An innovative cellulosic membrane supports the electrolyte, which avoids the undesirable characteristics of liquid electrolytes, and asbestos or ammonia that are substances that have been used to manufacture alkaline electrolyte membranes, which are knowingly toxic and carcinogenic. Aluminum is an inexpensive, abundant element in the earth’s crust and fully recyclable. Oxygen is supplied to the cell with atmospheric air that is pumped through a potassium hydroxide (KOH) aqueous solution in order to fix CO2, and in this way avoid potassium carbonate formation in order to keep the cell fully functional. A sustainable alkaline membrane fuel cell (SAMFC) system with one unitary cell, the reactor, and CO2 purifier was designed and built in the laboratory. The results are presented in polarization and power curves directly measured in the laboratory. Although recycled aluminum was used in the experiments, the results demonstrate that the cell was capable of delivering 0.9 V in open circuit and approximately 0.42 W of maximum power. The main conclusion is that by allowing for in situ sustainable hydrogen production, the SAMFC could eventually become economically competitive with traditional power generation systems.
Comparative Analysis of Diesel, Diesel-Palm Biodiesel and Diesel-Biodiesel-Butanol Blends in Diesel Engine
Authors: Hassan Md Mahmudul , Hagos Ftwi Yohaness , Mamat Rizalman
Published: October 2018

To reduce the dependency on fossil-based energy resources, the utilization of renewable fuels in unmodified diesel engines is gaining more emphasis from researchers in the recent years. The aim of the current study is to take part in the efforts being made to this regard by experimentally investigating a compression ignition engine fueled with different fuels ((diesel, diesel-biodiesel (B20), and diesel-biodiesel-butanol (BU20)) for their performance and emissions comparison. The experimental study was conducted in a water cooled single-cylinder direct injection (DI) diesel engine. It was operated at a constant engine operation speed of 1800 rpm and under varied engine load conditions. It is found that BU20 shows promising results in terms of performance and emissions characteristics as compared to using B20 and D100. Butanol addition to diesel-biodiesel blends is considered as an appropriate solution of higher density and viscosity the blend and thus for the sustainable usability of biodiesel. Maximum thermal efficiency improvement of 3.18% was observed at an engine load of 75%. The NOx emission was improved with BU20 as compared to the conventional diesel fuel (D100) at most of the engine loads. As an improvement on the engine performance and emissions is reported from the current study, the BU20 fuel blends can be used in similar engines with no further engine retrofitting. This blend can be a good environmental friendly fuel that can serve in the reduction of fossil-based diesel fuels. A further study on diesel engine tribology is required.
Thermal Analysis Safety Margins Using ABAQUS for the MP-2 Experiment in the Advanced Test Reactor
Authors: Hawkes Grant L. , Crawford Douglas S. , Housley Gregory K.
Published: October 2018

The Mini-Plate 2 (MP-2) irradiation test is a fueled experiment designed for irradiation in multiple test locations in the Advanced Test Reactor (ATR). MP-2 is considered a non-instrumented drop-in test where small aluminum-clad fuel plate samples are cooled directly by the ATR Primary Coolant System (PCS) water. The MP-2 fuel plate experiment will be irradiated in several different irradiation locations of the ATR. This fueled experiment contains aluminum-clad fuel mini plates consisting of monolithic U-Mo. Four different types of fuel plates were analyzed. A thermal analysis has been performed on the MP-2 experiment to be irradiated in the ATR at Idaho National Laboratory (INL). A new technique for calculating Departure from Nucleate Boiling Ratio (DNBR) and Flow Instability Ratio (FIR) using the commercial finite element and heat transfer code ABAQUS is demonstrated. This new technique calculates DNBR for the fuel plate surfaces and FIR for all water components for each finite element surface and node. Pressure drop data is fed into the calculations in order to geometrically calculate the water saturation temperature.

Results from the DNBR and FIR calculations are displayed with the ABAQUS post processor named Viewer. By calculating these parameters at each location in the finite element model, conservatism is replaced with accuracy. This allows for a greater margin for the thermal hydraulic safety parameters.
Water-Free Combined Cycle Power Plants for Distributed Power Generation
Authors: Welch Michael
Published: October 2018

Combined Cycle Gas Turbine (CCGT) power plant offer operators both environmental and economic benefits. The high efficiency achievable across a wide load range reduces both fuel costs and CO2 emissions to atmosphere. However, the scale of the power generation plays a major role in determining both cost and efficiency: a modern large centralized CCGT of 600MW output or more will have a full load efficiency in excess of 60% and a very competitive installed cost on a US$/kW basis. The smaller gas turbines required for distributed power applications are not optimized for combined cycle operation, with potential full load efficiencies of a combined cycle scheme ranging from a little over 40% to the high 50s depending on the power output of the gas turbine, the exhaust gas conditions and the plant configuration, while the installed cost is around twice that of a large centralized CCGT on a US$/kW basis.

The drawback of a conventional combined cycle plant design is the need for water, which is a scarce commodity in some regions. Air cooling of the CCGT plant can be used to reduce water consumption, but make-up water will still be required for the steam system to compensate for steam losses, blowdown etc.

While the lower exhaust gas temperatures of the smaller gas turbines impact the combined cycle efficiencies achievable, they do allow Organic Rankine Cycle (ORC) technology to be considered for an alternative combined cycle configuration. This paper compares both the capital and operating costs and performance of combined cycle power plants for distributed power applications in the 30MW to 250MW power range based on conventional steam and various different ORC configurations.
Distributed Power Generation and Energy Storage From Renewables Using a Hydrogen Oxygen Turbine
Authors: Schoenung Susan , Keller Jay
Published: October 2018

Renewable energy is best utilized when partnered with energy storage to balance the variable supply with daily and seasonal grid demands. At the distribution level, in addition to meeting power demands, there is a need to maintain system voltage and reactive power / VAR control. Rotating machinery is most effective for VAR control at the substation level. This paper presents a patented MW-scale system that provides power from a hydrogen-oxygen-fueled combined cycle power plant, where the hydrogen and oxygen are generated from electrolysis using renewable wind or solar power. The steam generated from combustion is the working fluid for the power plant, in a closed loop system. Also presented is a discussion on a patented strategy for safe combustion and handling of hydrogen and oxygen, as well as how to use this combustion strategy for flame and post flame temperature control. Finally, a preliminary benefits analysis illustrates the various energy storage and distributed generation benefits that are possible with this system. Depending on the storage approach, energy storage — charge and discharge durations — of 4 to greater than 24 hours are possible, much longer than most battery energy storage systems. Benefits include not only peak shaving and VAR control, but also grid balancing services to avoid the “spilling” of excess renewable power when supply exceeds demand and fast ramping in the evening hours.
Overview of Wind Turbine Field Failure Databases: A Discussion of the Requirements for an Analysis
Authors: Bakhshi Roozbeh , Sandborn Peter
Published: October 2018

With renewable energy and wind energy in particular becoming mainstream means of energy production, the reliability aspect of wind turbines and their sub-assemblies has become a topic of interest for owners and manufacturers of wind turbines. Operation and Maintenance (O&M) costs account for more than 25% of total costs of onshore wind projects and these costs are even higher for offshore installations. Effective management of O&M costs depends on accurate failure prediction for turbine sub-assemblies. There are numerous models that predict failure times and O&M costs of wind farms. All these models have inputs in the form of reliability parameters. These parameters are usually generated by researchers using field failure data. There are several databases that report the failure data of operating wind turbines and researches use these failure data to generate the reliability parameters through various methods of statistical analysis. However, in order to perform the statistical analysis or use the results of the analysis, one must understand the underlying assumptions of the database along with information about the wind turbine population in the database such as their power rating, age, etc. In this work, we analyze the relevant assumptions and discuss what information is required from a database in order to improve the statistical analysis on wind turbines’ failure data.
Application of Specific Entropy Generation to Enhance Thermal Efficiency of a Combined Cycle
Authors: Haseli Yousef
Published: October 2018

The method of specific entropy generation (SEG) is employed to show how the thermal efficiency of a combined cycle power plant can be improved. SEG is defined as the total entropy generation rate associated with the operation of a power plant per unit flowrate of the fuel burnt in the combustor. In a recent article published in Journal of Energy Resources and Technology, it is shown that the thermal efficiency of a gas turbine cycle inversely correlates with SEG. In this work, we extend the analysis to show that the same relation between the thermal efficiency and SEG is also valid for a combined cycle. The topping cycle consists of a compressor, a combustor and a gas turbine, whereas the bottoming cycle includes a heat recovery steam generator, a steam turbine, a condenser, a deaerator, a condensate pump and a feed water pump.

It is shown that the minimization of SEG is identical to the maximization of thermal efficiency. An illustrative example is presented using the SEG method to improve the efficiency of the combined cycle. The results reveal that 89% of the inefficiencies takes place in the gas turbine cycle. A modified design is then proposed to reduce the efficiency losses in the topping cycle. In the modified design, the thermal energy of the flue gases is first used in a heat exchanger to preheat the air before the combustor. The flue gases leaving the heat exchanger is then directed to the HRSG for producing steam. With this modification, the thermal efficiency and the power output of the combined cycle increase 2.7 percentage points and 20.9 kW per unit molar flowrate of the fuel. Recovering the thermal energy of the flue gases for both preheating the air and producing the steam appears to be more efficient than just producing the steam. Despite the net power production of the bottoming cycle decreases in the modified design, the overall efficiency of the combined cycle increases due to the improvement in the efficiency of the topping cycle.
Design and Performance of a Diaphragm Free-Piston Stirling Engine for Power Production From Low-Temperature Heat Sources
Authors: Nawafleh Anas , Asfar Khaled R.
Published: October 2018

This paper addresses modeling, design, and experimental assessment of a Gamma type low-temperature differential free-piston Stirling engine. The most advanced third-order design analysis method is used to model, simulate and optimize the engine. Moreover, the paper provides an experimental parametric investigation of engine physical parameters and operating conditions on the engine performance. The experimental test results are presented for a model validation, which shows about a 5% to 10% difference in the simulation results. The aim of this study is to design a Stirling engine capable of harvesting low-temperature waste heat effectively and economically and convert it to power. The engine prototype is designed to increase the engine performance by eliminating the main losses occurred in conventional Kinematic engines. Thus, elastic diaphragm pistons are used in this prototype to eliminate the surface friction of the moving parts, the use of lubricant, and to provide appropriate seals. In addition, flat plate heat exchangers, linear flexure bearing, a stainless-steel regenerator and a polyurethane displacer are outlined as the main components of the engine. Experiments successfully confirm the design models for output power and efficiency. Furthermore, it is revealed that the displacer-to-piston natural frequency ratio is an important design point for free-piston Stirling engines and should be addressed in the design for optimum power output.
Real Time Implementation of Standpipe Model for Solids Flow in Circulating Fluidized Bed
Authors: Panday Rupendranath , Shadle Lawrence , Breault Ronald
Published: October 2018

Increased accuracy of solids flow meters can be achieved with sensor fusion; the combination of solids velocity measurement with other process sensors to define the process state of the solids while they flow. In a circulating fluidized bed aeration flow, temperature measurements, and pressure differentials are routinely measured to ensure stable process operations. These process measurements were used as input to real-time model of the standpipe where the velocity measurement was taken to determine the actual solids bed density. The model development and implementation are described with the objective of updating the measured flows continuously in real time. Real time optimization techniques use the pressure measurements for inferring voidage and apply the inferred values to estimate the pressure profile and aeration split. In essence, the approach becomes solving nonlinear least squares problem and closure of mass balance of gas in real time.
A Validation of CFD Methods on Predicting Valve Performance Parameters
Authors: Duan Yu , Eaton Matthew D. , Bluck Michael J. , Jackson Christopher
Published: October 2018

The influence of mesh resolution, the abilities of various eddy viscosity models, and near wall flow treatments on predicting the flow coefficients of poppet valves, operating in water are investigated in this paper. The computational fluid dynamics (CFD) models are solved using STAR-CCM+ 12.04. Grid-convergence is studied first, followed by quantitative assessments of the ability of standard k-ε model, realizable k-ε model, EB k-ε model, Lag EB k-ε model, V2F model and k-ω-sst model, and different wall treatments, such as high y+ wall treatment, two-layer wall treatment and all y+ wall treatment, embedded in the solver. The flow discharge coefficient (Cq) of poppet valves predicted by CFD models are compared to physical measurements. It was demonstrated in the study that grid resolutions normal to the wall and mesh quality are key factors. Advanced near wall flow treatments produce similar or worse predictions when using the standard k-ε model, and the effects of the near wall flow treatments are marginal for the realizable k-ε model. The ability of turbulence models varies greatly in predicting flow in different valves and lift levels. The realizable k-ε model is the optimal option for the considered valve flows giving an acceptable error within ±5%.
Ancient genomes suggest the eastern Pontic-Caspian steppe as the source of western Iron Age nomads
Authors: Krzewińska Maja , Kılınç Gülşah Merve , Juras Anna , Koptekin Dilek , Chyleński Maciej , Nikitin Alexey G. , Shcherbakov Nikolai , Shuteleva Iia , Leonova Tatiana , Kraeva Liudmila , Sungatov Flarit A. , Sultanova Alfija N. , Potekhina Inna , Łukasik Sylwia , Krenz-Niedbała Marta , Dalén Love , Sinika Vitaly , Jakobsson Mattias , Storå Jan , Götherström Anders
Published: October 2018

Bronze and Iron Age genomes from the West Eurasian steppe reveal genetic heterogeneity and origins in the southern Urals.