bluuebunny/crossref_metadata_2025 huggingface dataset:
Impossible transmutations?
Authors: Disney Dan
Published: October 2014

Don Paterson's Orpheus (2006) is an English‐language version that transmutes Rilke's original Die Sonette an Orpheus (1922). Abandoning the imperative for prosodic equivalence and claiming instead to locate the ‘spirit of the original’, Paterson's sonnets can be reread as performing peculiar linguistic enactments of poetic truths exigent (philosopher Martin Heidegger claims) in Rilke's sonnets. In the essay ‘Poetically man dwells’, Heidegger claims ‘Poetry is a measuring’ and that the ‘nature of the image is to let something be seen’; elsewhere, the philosopher argues Rilke's work performs an illuminating projection of lexis (words) and logos (order, knowing). In his version, however, Paterson foregrounds variation when ushering the spirit of Rilke's images into English sounds: through a range of creative decisions (poiesis, techné, ekphrasis), the contemporary poet achieves gestural equivalence through his radical rewriting of Rilke's glimpsed truths.
Child and adolescent psychiatry in the Far East
Authors: Hirota Tomoya , Guerrero Anthony , Sartorius Norman , Fung Daniel , Leventhal Bennett , Ong Say How , Kaneko Hitoshi , Kim Bungnyun , Cho Soo‐Churl , Skokauskas Norbert ,   Consortium on Academic Child and Adolescent Psychiatry in the Far East (CACAP FE)
Published: October 2014

Aim

Despite the general consensus on the importance of youth mental health, the scarcity of child and adolescent mental health services is prominent all over the world. Child and adolescent psychiatry (CAP) postgraduate training can play a pivotal role in increasing access to youth mental health services. In comparison to Europe and North America, however, little is reported regarding CAP training in the Far East, one of the most dynamic and rapidly developing world regions with a very young population. This paper presents an original study on the current status of academic child and adolescent psychiatry training across the Far East.

Methods

We collected data from 17 countries in the Far East using an internally distributed questionnaire to the Consortium members invited for this study, consisting of leading academic child and adolescent psychiatrists in each country.

Results

Based on informants' input, we found an overall underdevelopment of CAP postgraduate training systems despite CAP's recognition as a subspecialty in 12 of 17 of the nations or functionally self‐governing areas in the Far East. Paucity of official guidelines for CAP training was also evident. All informants reported a need for additional child and adolescent mental health professionals.

Conclusion

There seems to be several obstacles to the development of CAP postgraduate training in the Far East, including stigma towards mental health issues and lack of funding. International collaboration is desired to develop evidence‐based and culture‐tailored CAP training systems.
Non‐clinical interventions for acute respiratory infections and diarrhoeal diseases among young children in developing countries
Authors: Seguin Maureen , Niño Zarazúa Miguel
Published: October 2014

Objective

To assess the effectiveness of non‐clinical interventions against acute respiratory infections and diarrhoeal diseases among young children in developing countries.

Methods

Experimental and observational impact studies of non‐clinical interventions aimed at reducing the incidence of mortality and/or morbidity among children due to acute respiratory infections and/or diarrhoeal diseases were reviewed, following the Cochrane Handbook for Systematic Reviews of Interventions and the PRISMA guidelines.

Results

Enhancing resources and/or infrastructure, and promoting behavioural changes, are effective policy strategies to reduce child morbidity and mortality due to diarrhoeal disease and acute respiratory infections in developing countries. Interventions targeting diarrhoeal incidence generally demonstrated a reduction, ranging from 18.3% to 61%. The wide range of impact size reflects the diverse design features of policies and the heterogeneity of socio‐economic environments in which these policies were implemented. Sanitation promotion at household level seems to have a greater protective effect for small children.

Conclusion

Public investment in sanitation and hygiene, water supply and quality and the provision of medical equipment that detect symptoms of childhood diseases, in combination of training and education for medical workers, are effective policy strategies to reduce diarrhoeal diseases and acute respiratory infections. More research is needed in the countries that are most affected by childhood diseases. There is a need for disaggregation of analysis by age cohorts, as impact effectiveness of policies depends on children's age.
Vulvodynia: integrating current knowledge into clinical practice
Authors: Nagandla Kavitha , Sivalingam Nalliah
Published: October 2014

Key content

Vulvodynia is a chronic gynaecological condition that results in significant distress to women and management can be challenging to the clinician.

The 2003 International Society for the Study of Vulvovaginal Disease (ISSVD) defines vulvodynia as vulval discomfort that is described as burning, stinging or irritation, in the absence of relevant visible findings or specific signs of a clinically identifiable neurological condition. The condition can be localised (vestibule) or generalised and the discomfort can be spontaneous or provoked by physical contact.

The diagnosis of vulvodynia is one of exclusion after inflammatory, infectious, dermatological, neoplastic, neurological and psychosexual conditions have been ruled out.

A multidisciplinary approach to tackle the different components of vulvodynia is required that includes a lead clinician with clinical psychologist, physiotherapist, psychosexual medicine clinician and pain management specialist.

Owing to the heterogeneity in the aetiology of the condition, multimodal therapy is recommended in most cases.

Learning objectives

To review the current classification and pathophysiology of vulvodynia.

To review the clinical manifestation and diagnosis of a patient with generalised and localised vulvodynia.

To critically appraise the currently available treatments options for vulvodynia.

Ethical issues

Psychosexual dysfunction related to this disorder raises the sensitive issue of open communication with the individual or couple on varying degrees of sexual and psychological counselling.

Ethical issues that are realised in determining the cause of vulvodynia include sexual orientation and history of sexual abuse.

How does evidence‐based medicine direct health professionals in the treatment of this condition?
Counselling women about the risks of caesarean delivery in future pregnancies
Authors: Dahlke Joshua D , Mendez‐Figueroa Hector , Wenstrom Katharine D
Published: October 2014

Key content

In order to provide appropriate counselling about the risk to future pregnancies imposed by caesarean delivery, providers must be knowledgeable about and able to synthesise a multitude of variables such as institutional policies, the clinical implications of each current delivery option for future pregnancies, patient understanding of maternal and neonatal risks and benefits, the woman's reasons for requesting this type of delivery and the woman's desired family size.

The rate of successful vaginal birth after caesarean section ranges 50–85%, with lower rates associated with both modifiable factors (gestational age >40 weeks, maternal obesity, short interpregnancy interval and increased birthweight) and non‐modifiable factors (maternal age, non‐white ethnicity, pre‐eclampsia and recurrence of the indication for the initial caesarean delivery).

In future pregnancies, the risk of adverse outcomes such as haemorrhage, endometritis, operative injury, hysterectomy and maternal death goes up with each additional caesarean section.

Learning objectives

To be knowledgeable about and able to provide accurate counselling for three important clinical situations: caesarean delivery on maternal request; women with a history of one or two caesarean deliveries; and women with a history of three or more caesarean deliveries.

Ethical issues

When counselling women about the risks of caesarean delivery on future pregnancies, providers should always consider the principles of beneficence and non‐maleficence while synthesising a myriad of scenarios and outcomes. If properly counselled on the risks, benefits and alternatives of a delivery decision, her autonomy should be respected.
The use of mifepristone and misoprostol in the management of late intrauterine fetal death
Authors: Nzewi Chuks , Araklitis George , Narvekar Nitish
Published: October 2014

Key content

A combination of mifepristone and misoprostol is the gold standard treatment for induction of labour in women with late intrauterine fetal death.

This article attempts to review the current best available evidence as well as provide an insight based on the available evidence regarding the dosing regimens and safety in women with a previous caesarean section.

Learning objectives

To review the pharmacokinetics, mode of action, efficacy, adverse effects, dose and route of administration of mifepristone and misoprostol.

To review the safety of misoprostol in women with previous caesarean section and other uterine scars.

Ethical issues

To identify the most effective regimen with the fewest adverse effects.

To balance the desire to achieve a quick and successful induction with the risk of complications including uterine rupture in women with previous uterine scars.

To provide a sympathetic approach to women who are already emotionally stressed.
Export Spillovers: Opening the Black Box
Authors: Choquette Eliane , Meinen Philipp
Published: October 2014

This paper studies the importance of export spillovers in a firm's decision to enter specific export markets and extends the current state of the literature by assessing different mechanisms through which they may occur, namely (i) labour movement, (ii) intra‐industry spillovers and (iii) inter‐industry linkages. We do so by exploiting a unique data set covering the universe of manufacturing firms in Denmark for the period 1995–2006 which combines transaction‐level export data, firm accounting data, employer–employee linked data and information from yearly input–output tables. We corroborate the literature on export spillovers by presenting robust evidence of destination‐specific export spillovers. The results suggest that labour mobility as well as intra‐ and inter‐industry linkages (backward linkages) are important channels for export spillovers, while presenting heterogeneous effects across firms of different size and export markets.
Automorphy and irreducibility of some l-adic representations
Authors: Patrikis Stefan , Taylor Richard
Published: October 2014

In this paper we prove that a pure, regular, totally odd, polarizable weakly compatible system of $l$-adic representations is potentially automorphic. The innovation is that we make no irreducibility assumption, but we make a purity assumption instead. For compatible systems coming from geometry, purity is often easier to check than irreducibility. We use Katz’s theory of rigid local systems to construct many examples of motives to which our theorem applies. We also show that if $F$ is a CM or totally real field and if ${\it\pi}$ is a polarizable, regular algebraic, cuspidal automorphic representation of $\text{GL}_{n}(\mathbb{A}_{F})$, then for a positive Dirichlet density set of rational primes $l$, the $l$-adic representations $r_{l,\imath }({\it\pi})$ associated to ${\it\pi}$ are irreducible.
A study of the representations supported by the orbit closure of the determinant
Authors: Kumar Shrawan
Published: October 2014

We show the existence of a large family of representations supported by the orbit closure of the determinant. However, the validity of our result is based on the validity of the celebrated ‘Latin square conjecture’ due to Alon and Tarsi or, more precisely, on the validity of an equivalent ‘column Latin square conjecture’ due to Huang and Rota.
Two-Phase Thermal Ground Planes: Technology Development and Parametric Results
Authors: Bar-Cohen Avram , Matin Kaiser , Jankowski Nicholas , Sharar Darin
Published: October 2014

Defense Advanced Research Project Agency's (DARPA's) thermal ground plane (TGP) effort was aimed at combining the advantages of vapor chambers or two-dimensional (2D) heat pipes and solid conductors by building thin, high effective thermal conductivity, flat heat pipes out of materials with thermal expansion coefficients that match current electronic devices. In addition to the temperature uniformity and minimal load-driven temperature variations associated with such two phase systems, in their defined parametric space, flat heat pipes are particularly attractive for Department of Defense and commercial systems because they offer a passive, reliable, light-weight, and low-cost path for transferring heat away from high power dissipative components. However, the difference in thermal expansion coefficients between silicon or ceramic microelectronic components and metallic vapor chambers, as well as the need for a planar, chip-size attachment surface for these devices, has limited the use of commercial of the shelf flat heat pipes in this role. The primary TGP goal was to achieve extreme lateral thermal conductivity, in the range of 10 kW/mK–20 kW/mK or approximately 25–50 times higher than copper and 10 times higher than synthetic diamond, with a thickness of 1 mm or less.
Flow Behavior of Two-Dimensional Wet Foam: Effect of Foam Quality
Authors: Jing Zefeng , Wang Shuzhong , Lv Mingming , Wang Zhiguo , Luo Xiangrong
Published: October 2014

The flow behaviors of two-dimensional (2D) wet monodisperse and polydisperse foams are investigated by the quasi-static simulation. We set the same inlet velocity on the cross section of the foam channel and then focus on the elastic–plastic deformation of the 2D wet foam according to the strain caused by the foam flow. The gas fraction in foam is referred to as foam quality and the effects of foam quality on the shear modulus, bubble dynamics, and stress–strain properties are obtained by the simulation. In the elastic domain, the shear modulus of monodisperse foam decreases exponentially with foam quality, but for the polydisperse foam, the shear modulus tends to increase. The shear banding of the polydisperse foam appears in the low strain and disappears gradually as the strain and foam quality increase. We adopt shear rate to represent the change rate of average bubbles displacements versus y-coordinates and find that the distribution of shear rate in the y-direction changes with iteration. Additionally, energy of the foam is stored and dissipated with the elastic–plastic deformation of the foam. The average shear stress generated by the foam structure and the initial increment of normal stress difference caused by the elastic deformation increase with the increase of foam quality.
Analytic Models of a Thin Glass–Polymer Laminate and Development of a Rational Engineering Design Methodology
Authors: Shitanoki Yuki , Bennison Stephen J. , Koike Yasuhiro
Published: October 2014

Analytic models that describe the mechanical behavior of thin glass–polymer laminate structures have been investigated experimentally and via finite-element analysis (FEA). Standard laminate effective thickness models were shown to be applicable to a wide range of glass/interlayer thickness ratios and to a wide range of interlayer shear moduli, covering most currently existing glass laminates. In addition, an analytic comparison of the effective thickness model with the traditional composite beam model clarified the applicable limits of the former model in the range of the interlayer/glass thickness ratio and interlayer shear modulus. These modeling approaches enable a rational engineering design approach for structurally efficient, lightweight, and safe glazing laminates.
Geographical Limitations on Integral Collector Storage Collectors Due to Freezing
Authors: Schollenberger Frederick S. , Kreith Frank , Burch Jay
Published: October 2014

Passive integral collector storage (ICS) solar water heaters can potentially heat water at lower costs then active systems with freeze protection. However, ICS panels can freeze in cold weather. This study developed a model relating the freeze behavior to climate conditions, validated the model experimentally and then ran the model with long term U.S. weather data to delineate regions safe for the passive solar heaters. Both, a single- and a double-glazed tubular ICS panels were modeled and tested. It was found that freezing begins when the water in the supply/return lines freezes and initiates a pressure build up in the collector which can eventually burst the large collector tubes when the water inside freezes and expands. It was found that freezing can be delayed by installing heat tape over the supply/return lines. Using a model of the collector and TMY2 weather data, correlation maps were developed to show in which regions of the U.S. ICS panels with and without heat tapes can be installed safely.
Elastohydrodynamic Lubrication Analysis of Pure Squeeze Motion on an Elastic Coating/Elastic Substrate System
Authors: Chu Li-Ming , Yu Chi-Chen , Chen Qie-Da , Li Wang-Long
Published: October 2014

A rigid sphere approaching a lubricated flat surface with a layer of elastic coating on the elastic substrate is explored under constant load conditions. The transient pressure profiles, film shapes, elastic deformation, von Mises stress (σvon) during the pure squeeze process under various operating conditions in the elastohydrodynamic lubrication (EHL) regime are discussed. The simulation results reveal that the greater the Young's modulus of coating is, the greater the pressure distribution is, the smaller the contact area is, and the greater the maximum stress (σvon) value is. As the Young’s modulus of coating decreases, the central elastic deformation at the surface (Z = 0) increases and the deformation at the interface of coating/substrate (Z = −1) decreases. For hard coating cases, the maximum central pressure increases to an asymptotic value and minimum film thickness decreases to an asymptotic value as the coating thickness increases. For soft coating cases, this phenomenon reverses. A thicker and stiffer coating leads to a higher maximum stress. At the deformation recovery stage, the positions of the maximum stress would begin to offset downwards and closer to the coating/substrate interface. Moreover, the position of maximum stress varies from the coating to the subsurface as the Young’s modulus of coating increases. The EHL with stress analysis can prevent the chance of fracture in coating or substrate. These characteristics are important for the lubrication design of mechanical elements with coatings.
Tool Wear Monitoring of Wiper Inserts in Multi-Insert Face Milling Using Three-Dimensional Surface Form Indicators
Authors: Wang Meng , Ken Te , Du Shichang , Xi Lifeng
Published: October 2014

The wear of wiper inserts directly affects the finishing surface quality in multi-insert face milling. This research aims at monitoring the wear of wiper inserts, using 3D surface form as tool wear indicators. 3D surface height map of the face-milled surface is measured by a high definition metrology (HDM) instrument and converted into height-encoded and toolmark-straightened gray images. 3D surface form indicators, including entropy and contrast, are extracted from the converted images with a modified gray level co-occurrence matrix (GLCM) method. Meanwhile, the wear of wiper inserts is measured using a tool presetter and measuring machine without dismounting wiper inserts from the cutter. Experimental results indicate that entropy shows a strong correlation with average axial wear of the wiper edges and contrast reflects the evolution of axial offset between wiper inserts.
Estimating Lifetime of Notched Components Subjected to Variable Amplitude Fatigue Loading According to the Elastoplastic Theory of Critical Distances
Authors: Susmel Luca , Taylor David
Published: October 2014

The present paper is concerned with the use of the elastoplastic theory of critical distances (TCD) to perform the fatigue assessment of notched components subjected to in-service variable amplitude (VA) fatigue loading. The elastoplastic TCD takes as its starting point the assumption that the detrimental effect of stress/strain concentrators of any kind can efficiently be taken into account by directly postprocessing the entire elastoplastic stress/strain field in the vicinity of the notch apex. Thanks to its specific features, the TCD can be formalized in different ways by simply changing size and geometrical features of the domain used to calculate the required effective stress. The so-called point method (PM) is the simplest form in which this theory can be applied. This formalization of the TCD postulates that the elastoplastic stress/strain state to be used to estimate fatigue damage has to be determined at a given distance from the tip of the notch being assessed. According to the TCD's philosophy, such a distance is treated as a fatigue property. Therefore, given the material, this critical length does not change as either the features of the assessed stress/strain concentrator or the profile of the investigated loading path vary. In the present study, the above design strategy is attempted to be used to estimate lifetime of notched component subjected to VA loading, the required critical distance being determined under constant amplitude (CA) loading. The accuracy and reliability of the devised approach were checked by using a number of experimental results generated by testing, under both concave upward and concave downward spectra, notched samples containing geometrical features having a different sharpness. Such a validation exercise allowed us to prove that the elastoplastic TCD, used in the form of the PM, is highly accurate in estimating fatigue damage also in notched components subjected to in-service VA loading.
Dynamics of a Superconducting Linear Slider
Authors: Valiente-Blanco Ignacio , Perez-Diaz Jose-Luis , Diez-Jimenez Efren
Published: October 2014

In this paper, the dynamic behavior of a one degree-of-freedom (DOF) contactless linear slider based on superconducting magnetic levitation is experimentally analyzed. The device is intended for precision positioning of an optic mirror in cryogenic environments. Different prototypes of this device have been tested at cryogenic temperatures (77 K), and their mechanical behavior characterized in the sliding direction for forced and unforced oscillations. Experimental results reveal that the slider is self-stable at the initial equilibrium position and the dynamic behavior fits well an underdamped harmonic oscillator. Finally, the device showed great potential for horizontal vibration isolation, acting as a low-pass filter with a resonance at about 0.9 Hz.
Exergy-Based Optimization of Sub- and Supercritical Thermal Energy Storage Systems
Authors: Tse Louis A. , Lakeh Reza Baghaei , Wirz Richard E. , Lavine Adrienne S.
Published: October 2014

In this work, energy and exergy analyses are applied to a thermal energy storage system employing a storage medium in the two-phase or supercritical regime. First, a numerical model is developed to investigate the transient thermodynamic and heat transfer characteristics of the storage system by coupling conservation of energy with an equation of state to model the spatial and temporal variations in fluid properties during the entire working cycle of the TES tank. Second, parametric studies are conducted to determine the impact of key variables (such as heat transfer fluid mass flow rate and maximum storage temperature) on both energy and exergy efficiencies. The optimum heat transfer fluid mass flow rate during charging must balance exergy destroyed due to heat transfer and exergy destroyed due to pressure losses, which have competing effects. Similarly, the optimum maximum storage fluid temperature is evaluated to optimize exergetic efficiency. By incorporating exergy-based optimization alongside traditional energy analyses, the results of this study evaluate the optimal values for key parameters in the design and operation of TES systems, as well as highlight opportunities to minimize thermodynamic losses.
Potential of Electricity Generation by the Salinity Gradient Energy Conversion Technologies in the System of Urmia Lake-Gadar Chay River
Authors: Emdadi Arash , Emami Yunus , Zenouzi Mansour , Lak Amir , Panahirad Behzad , Lotfi Aydin , Lak Farshad , Kowalski Gregory J.
Published: October 2014

Energy production from salinity gradients is one of the developing renewable energy sources, and has significant potential for satisfying electrical demands. Urmia Lake is the second hyper-saline lake in the world and there is a significant salinity gradient between the lake’s water and the waters of those rivers that flow into the lake. A methodology for determining the feasibility for electrical production using Salinity Gradient Power (SGP) is developed for two different types of systems using this location as an example. Reverse Electrodialysis (RED) and Pressure Retarded Osmosis (PRO), The Gadar Chay River is one of thirteen rivers that run into Urmia Lake; it supports about 10% of the lake’s water. In this study, important parameters such as river discharge and the salinity content of river and lake’s waters for several years were investigated. The theoretical and technical potential of salinity gradient energy was also determined. These calculations indicate that 206.08 MW of electrical power could be produced at this location when the river flow is approximately 29.82 m3/s and they illustrates the potential for salinity gradient energy extraction between Urmia Lake and The Gadar Chay River.
Volume Sizing for Thermal Storage With Phase Change Material for Concentrated Solar Power Plant
Authors: Xu Ben , Li Peiwen , Chan Cholik
Published: October 2014

With a large capacity thermal storage system using phase change material (PCM), Concentrated Solar Power (CSP) is a promising technology for high efficiency of solar energy utilization. In a thermal storage system, a dual-media thermal storage tank is typically adopted in industry for the purpose of reducing the use of the heat transfer fluid (HTF). While the dual-media sensible heat storage system has been well studied, a dual-media latent heat storage system (LHSS) still needs more attention and study; particularly, the sizing of volumes of storage tanks considering actual operation conditions is of significance. In this paper, a strategy for LHSS volume sizing is proposed, which is based on computations using an enthalpy-based 1D model. One example of 60MW solar thermal power plant with 35% thermal efficiency is presented. In the study, potassium hydroxide (KOH) is adopted as PCM and Therminol VP-1 is used as HTF. The operational temperatures of the storage system are 390°C and 310°C, respectively for the high and low temperatures. The system is assumed to operate for 100 days with 6 hours charge and 6 hours discharge every day. From the study, the needed height of the thermal storage tank is calculated from using the strategy of tank sizing. The method for tank volume sizing is of significance to engineering application.
Cobalt Oxide-Based Structured Thermochemical Reactors/Heat Exchangers for Solar Thermal Energy Storage in Concentrated Solar Power Plants
Authors: Agrafiotis Christos , Roeb Martin , Sattler Christian
Published: October 2014

Based on the characteristics of the oxide redox pair system Co3O4/CoO as a thermochemical heat storage medium and the advantages of porous ceramic structures like honeycombs and foams in heat exchange applications, the idea of employing such ceramic structures coated with or manufactured entirely from a redox material like Co3O4, has been implemented.

Thermo-Gravimetric Analysis (TGA) experiments have demonstrated that laboratory-scale Co3O4-coated, redox-inert ceramic foams and honeycombs exhibited repeatable, cyclic reduction-oxidation operation within the temperature range 800–1000°C, employing all the redox material incorporated, even at loading levels exceeding 100 wt% loading percentages.

To further improve the volumetric heat storage capacity, monolithic porous ceramic foams made entirely of Co3O4 were manufactured, together with analogous pellets. Such porous structures were also capable of cyclic reduction–oxidation, exploiting the entire amount of Co3O4 used in their manufacture. In this perspective, “open” porous structures like the ones of ceramic foams seem to have significant advantages in addressing problems associated with cyclic expansion-contraction that could be detrimental to structural integrity.
Predicted Performance of a Ceramic Foam Gas Phase Heat Recuperator for a Solar Thermochemical Reactor
Authors: Bala Chandran Rohini , Banerjee Aayan , Davidson Jane H.
Published: October 2014

The efficiency of solar thermochemical cycles to split water and carbon dioxide depends in large part on highly effective gas phase heat recovery. Heat recovery is imperative for approaches that rely on an inert sweep gas to reach low partial pressures of oxygen during thermal reduction and/or use excess oxidizer to provide a higher thermodynamic driving potential for fuel production. In this paper, we analyze heat transfer and pressure drop of a tube-in-tube ceramic heat exchanger for the operating conditions expected in a prototype solar reactor for isothermal cycling of ceria. The ceramic tubes are filled with reticulated porous ceramic (RPC). The impacts of the selection of the composition and morphology of the RPC on heat transfer and pressure drop are explored via computational analysis. Results indicate a 10 pore per inch (ppi), 80–85% porous alumina RPC yields effectiveness from 85 to 90 percent.
Reverse Electrodialyis Salinity Gradient Power Experiment
Authors: Amaral Sean , Franklin Neil , Jurkowski Michael , Zenouzi Mansour
Published: October 2014

Today’s rate of fossil fuel consumption rapidly depletes fuel reserves and leads to a number of adverse environmental effects. Although the scope of these effects has yet to be fully realized, it is clear that the development of alternative energy sources is very important. A relatively new form of alternative energy known as reverse electrodialysis (RED) appears to be one of the promising energy sources of the future. This technology harvests the energy stored in the salinity gradient between two different liquids, and converts it directly into electric power. This power is generated by pumping water through an array of alternating pairs of cation and anion exchange membranes called cells. Various academic sources calculate the available energy to be 1.5 MJ for every cubic meter of sea and river water mixed, making all river basins a potential location for power production.

Small prototype systems using 50 cells with areas of 100 cm2 were assembled by a group in the Netherlands, but larger stacks remain to be tested. An understanding of the feasibility of RED as a possible energy source relies on testing of cells with larger membrane area and different numbers of membrane pairs. An experimental system was designed with cells 61 cm × 16.5 cm, which will increase the output by nearly a factor of 10. Along with having much larger dimensions than previous systems, the design has an adjustable number of cells in the stack, allowing users obtain test results at a variety of settings. Comparing the output of systems with few cells to systems with many cells will help us to optimize the stack size in terms of hydrodynamic losses.

Initial testing of the system resulted in a positive result. The tests showed that the system produced power, and the 1.98 volts measured was 83% of the predicted value. Leakage of the electrode rinse solution contaminated the membranes, and prevented more testing. Once the electrode rinse system is redesigned, more testing will be done.
The Use of Plug-In Hybrid Electric Vehicles for Peak Shaving
Authors: Tse Charles G. , Maples Benjamin A. , Kreith Frank
Published: October 2014

This article is a feasibility analysis of using the batteries in Plug-in Hybrid Electric Vehicles (PHEVs) for peak shaving. The analysis focuses on energy availability of the PHEV fleet as well as the financial savings to the utilities by analyzing different charging scenarios and circuitry.

The energy availability and the financial savings are heavily dependent on the location and availability of charging stations. Three charging scenarios are analyzed: charging is possible at any time; cars can only be charged overnight; charging can be done overnight and twice during the day at the place of work for cars that are used for commuting.

The major findings of the study are that charging only overnight will not provide sufficient energy when needed, but both other charging mechanisms can provide effective peak shaving. The charging anytime would require funding a large number of charging station, but charging overnight and at work could be accomplished with relative minor financial investments. The savings from peak shaving could be used for incentives to offset the extra cost of batteries in plug-in electric vehicles.
Fluid Charge and Discharge Strategies of Dual-Media Thermal Storage Systems in the Starting-Up Process of Daily Cyclic Operations
Authors: Xu Ben , Li Peiwen , Chan Cholik
Published: October 2014

Because of the capability of large capacity thermal storage and extended operation during night and cloudy days, concentrated solar thermal power generation is getting more and more attention in the recent years. Dual-media thermal energy storage system is typically adopted in industry for reducing the use of the heat transfer fluid, which is usually expensive. In such a dual-media system, the solid filler material can be a phase change material relying on latent heat or a regular solid material using sensible heat for energy storage. Two strategies of starting-up fluid charge and discharge are considered for the operation of a concentrated solar thermal power plant incorporated with a dual-media thermal storage system. These two strategies include: 1) starting daily cyclic charge and discharge operation with an initially cold tank; 2) to fully charge the thermal storage system before operation of the cyclic discharge/charge for the power plant. The energy storage efficiency and the effects to the power plant operation due to the application of these two strategies are studied in the current work based on an enthalpy-based 1-D model, and significant difference is found in starting-up process of the daily cyclic operations, which will help us decide the best strategy of operating a thermal energy storage system with more electrical energy output.
Measurement of Laminar Burning Speeds and Investigation of Flame Stability of Acetylene (C2H2)/Air Mixtures
Authors: Rokni Emad , Moghaddas Ali , Askari Omid , Metghalchi Hameed
Published: October 2014

Laminar burning speeds and flame structures of spherically expanding flames of mixtures of acetylene (C2H2) with air have been investigated over a wide range of equivalence ratios, temperatures, and pressures. Experiments have been conducted in a constant volume cylindrical vessel with two large end windows. The vessel was installed in a shadowgraph system equipped with a high speed CMOS camera, capable of taking pictures up to 40,000 frames per second. Shadowgraphy was used to study flame structures and transition from smooth to cellular flames during flame propagation. Pressure measurements have been done using a pressure transducer during the combustion process. Laminar burning speeds were measured using a thermodynamic model employing the dynamic pressure rise during the flame propagation. Burning speeds were measured for temperature range of 300 to 590 K and pressure range of 0.5 to 3.3 atmospheres, and the range of equivalence ratios covered from 0.6 to 2. The measured values of burning speeds compared well with existing data and extended for a wider range of temperatures. Burning speed measurements have only been reported for smooth and laminar flames.
Multi-Regional Multi-Objective Optimization of an Algal Biofuel Polygeneration Supply Chain With Fuzzy Mathematical Programming
Authors: Ubando Aristotle T. , Cuello Joel L. , El-Halwagi Mahmoud M. , Culaba Alvin B. , Tan Raymond R.
Published: October 2014

A polygeneration approach is proposed to improve the economic viability of algal biofuel production through simultaneous production of co-products (i.e. electricity, heat, and other biochemicals). A multi-regional polygeneration supply chain consists of various array of processing plants in producing multiple bioenergy products given spatial constraints of each plant found in different regions. The inherent complexity of the polygeneration compounds the difficulty of designing the composite network of processing plants in multi-regions. Optimizing the design flow of the polygeneration supply chain considers multiple objectives, such as satisfying product demand, maximizing economic performance, and minimizing environmental footprint. In addition, the optimal strategic capacity design of the supply and distribution of biodiesel across multi-regions are considered. This study uses a fuzzy mathematical programming model to generate an optimized design of the polygeneration supply chain while satisfying all objectives. The developed model is demonstrated using a modified industrial case study comparing two cultivation alternatives. Results showed that all fuzzy multi-objective goals are satisfied and the flat-plate photobioreactor is the preferred cultivation system in terms of environmental footprints and economic performance.
Low-Cost Lightweight Thin Film Solar Concentrators
Authors: Ganapathi Gani B. , Palisoc Art , Nesmith Bill , Greschik Gyula , Gidanian Koorosh , Kindler Andrew
Published: October 2014

A low-cost rigid foam-based concentrator technology development program was funded by the DOE SunShot Initiative to meet installed cost goals of $75/m2 vs. current costs of $200–250/m2. The cost reduction in this approach focuses primarily on designing a mirror module with a rigid foam center with stainless steel facesheets and reflective film. The low mechanical strength of the foam is compensated by optimizing the densities and dimensions to meet pointing accuracy requirements of 4 milliradians (mrad) in 27mph winds. Two alpha concentrators were built to validate the mirror module manufacturing process and one of them was accurate to 0.15 mrad RMS vs. the design requirement of 1 mrad RMS. To understand the lifetime reliability of the panels, fifteen 4-inch square samples were exposed to various environmental conditions including acid rain, bird droppings, thermal cycling, and the final results indicated no loss in reflectivity of 95%. UV testing will be performed in the next phase. Three mechanical structure options covering the range of large multi-faceted heliostats with diagonal load carrying elements, small single facet heliostats low to the ground and optimized truss-based deep structure designs were analyzed with FEA and analytically; results indicated a significant cost benefit (>2×) for the truss-based design over the other options. Other elements such as the controls, actuators were also considered in th analysis with vendor data. Cost trades were performed for heliostats ranging from 10m2 to 250m2. The results indicated a broad installed cost minimum around $113/m2 for heliostat sizes ranging from 80 m2 to 130 m2. Additional cost saving approaches will be considered in Phase 2 of the project.
Development of a Ceramic Pressurized Volumetric Solar Receiver for Supercritical CO2 Brayton Cycle
Authors: Khivsara S. D. , Das Rathindra Nath , Thyagaraj T. L. , Dhar Shriya , Srinivasan V. , Dutta P.
Published: October 2014

Recently, the supercritical CO2 (s-CO2) Brayton cycle has been identified as a promising candidate for solar-thermal energy conversion due to its potentially high thermal efficiency (50%, for turbine inlet temperatures of ∼ 1000K). Realization of such a system requires development of solar receivers which can raise the temperature of s-CO2 by over 200K, to a receiver outlet temperature of 1000K. Volumetric receivers are an attractive alternative to tubular receivers due to their geometry, functionality and reduced thermal losses. A concept of a ceramic pressurized volumetric receiver for s-CO2 has been developed in this work. Computational Fluid Dynamics (CFD) analysis along with a Discrete Ordinate Method (DOM) radiation heat transfer model has been carried out, and the results for temperature distribution in the receiver and the resulting thermal efficiency are presented. We address issues regarding material selection for the absorber structure, window, coating, receiver body and insulation. A modular small scale prototype with 0.5 kWth solar heat input has been designed. The design of a s-CO2 loop for testing this receiver module is also presented in this work.
Optical Modeling of Reflectivity Loss Caused by Dust Deposition on CSP Mirrors and Restoration of Energy Yield by Electrodynamic Dust Removal
Authors: Stark Jeremy , Yellowhair Julius , Hudelson John N. , Horenstein Mark , Mazumder Malay
Published: October 2014

For large scale CSP power plants, vast areas of land are needed in deserts and semi-arid climates where uninterrupted solar irradiance is most abundant. These power facilities use large arrays of mirrors to reflect and concentrate sunlight onto collectors, however, dust deposition on the optical surfaces causes obscuration of sunlight, resulting in large energy-yield losses in solar plants. This problem is compounded by the lack of natural clean water resources for conventional cleaning of solar mirrors, often with reflective surface areas of large installations exceeding a million square meters. To investigate the application of transparent electrodynamic screens (EDS) for efficient and cost effective dust removal from solar mirrors, both optical modeling and experimental verifications were performed. Prototype EDS-integrated mirrors were constructed by depositing a set of parallel transparent electrodes into the sun-facing surface of solar mirrors and coating electrodes with thin transparent dielectric film. Activation of the electrodes with a three-phase voltage creates an electrodynamic field that charges and repels dust electrostatically by Coulomb force and sweeps away particles by a traveling electrodynamic wave. We report here brief discussions on (1) rate of deposition and the properties of dust with respect to their size distribution and chemical composition in semi-arid areas of the southwest US and Mojave Desert and their adhesion to solar mirrors, (2) optical models of: (a) specular reflection losses caused by scattering and absorption by dust particles deposited on the surface based on Mie scattering theory, and (b) reflection loss by the integration of EDS on the mirror surface, computed by FRED ray-tracing model. The objective is to maintain specular reflectivity of 90% or higher by frequent removal of dust by EDS. Our studies show that the incorporation of transparent EDS would cause an initial loss of 3% but would be able to maintain specular reflectivity more than 90% to meet the industrial requirement for CSP plants. Specular reflection measurements taken inside a climate controlled environmental chamber show that EDS integration can restore specular reflectivity and would be able to prevent major degradation of the optical surface caused by the deposition of dust.
System and Market Analysis of Methanol Production Using Compact Engine Reformers
Authors: Acocella Angi , Lim Emmanuel , Cedrone Kevin , Bromberg Leslie , Seethamraju Srinivas , Cohn Daniel , Green William
Published: October 2014

New energy plants coming online must be both economical and efficiently balanced to satisfy demanding requirements in the future. A balance of plant analysis was performed to determine the techno-economic feasibility of a 100 barrel oil equivalent (boe) per day, compact Gas to Liquid (GTL) methanol plant. Methanol itself is emerging as a possible alternative to gasoline; but it is also the precursor to dimethyl ether (DME), which has recently received a lot of attention as a low emitter of particulate matter and nitrous oxides, which can replace diesel in trucking applications and liquefied petroleum gas (LPG) in domestic applications. Production of synthesis gas (syngas) from methane gas was modeled via partial oxidation of fuel-rich mixtures in engine cylinders using GT-ISE. Two ignition modes were studied: spark ignition (SI) and homogeneous charge compression ignition (HCCI). The use of the engine as a compressor was also studied in order to reduce net compression requirements and therefore capital and operating costs. The low brake mean effective pressure (BMEP) allowed in HCCI operation substantially limits both the throughput and capability to produce high-pressure syngas. The use of mechanical power generated by the engine reformer to power other components such as compressors and the air separation unit (ASU) have been studied. The waste heat produced from the engine and methanol synthesis reactors was also considered in the analysis. Integration of all components in the system was performed in Aspen Plus.

To inform plant design, a survey was performed of vendors with small-scale methanol synthesis technologies that could integrate an engine reformer. Aspen Process Economic Analyzer (APEA) was also used to generate estimates of plant component costs. A study of the profitability and payback period of the technology was performed to determine the cost to produce methanol based on the balance of plant analysis. The results of this analysis were used to gauge the technology’s feasibility and therefore provided constructive feedback to guide future plant design.
Experimental Investigation of Biomass Pellets and Pelletizing Process Using Hardwood and Switchgrass
Authors: Eggerstedt Kyle , Wang Xia
Published: October 2014

Biomass fuel has been utilized as a renewable energy resource to replace or supplement fossil fuels. Combustion characteristics of biomass affect the utilization of biomass pellets. Activation energy, ash content, energy content, moisture content, density, and durability are a few parameters that are analyzed for ideal combustion. An ideal fuel can be created through analyzing multiple biomass materials and pelletizing procedures. The objective of this research is to improve biomass performance by investigating its pelleting parameters and the related combustion characteristics. A lab scale pelletizing process was developed with the pelletizing conditions being 150°C for 150 seconds under a pressure of 4500 psi. A total of 45 different types of pellets with a diameter of 2.5cm and a thickness of 5mm were created using the new pelletizing process. They had five different material mixtures (100% hardwood (HW), 75/25hardwood/switchgrass (HS), 50/50HS, 25/75HS, and 100% switchgrass (S)), three different original moisture contents (15%, 20%, and 25%), and 3 different amounts of binder (1/6, 1/12, and 0). Trends of the combustion characteristics to pelletizing process parameters were found. When the material mixture changes from pure hardwood to pure switchgrass, both activation energy decreases while ash content increases. When the binder decreases, activation energy increases as well as ash content while both energy content and durability decrease.