bluuebunny/crossref_metadata_2025 huggingface dataset:
Crystallographic Structure and Ferroelectricity of (AxLa1−x)2Ti2O7 (A = Sm and Eu) Solid Solutions with High Tc
Authors: Chen Chen , Gao Zhipeng , Yan Haixue , Reece Mike J.
Published: October 2015

The solubility and ferroelectric properties of (AxLa1−x)2Ti2O7 (A = Sm and Eu) solid solutions were investigated. The crystallographic structure of the solid solutions was studied using X‐ray diffraction and Raman spectroscopy. The solubility limits of Eu and Sm in (AxLa1−x) 2Ti2O7 were found to be greater than x = 0.5 and 0.8, respectively. The solid solutions had a monoclinic perovskite‐like layered structure (PLS), similar to that of the pure La2Ti2O7, when x was less than the solubility limit. When x was above the solubility limit the materials were biphase. The biphases of (SmxLa1−x)Ti2O7 (x = 0.9) consisted of (SmxLa1−x)2Ti2O7 with PLS and pure Sm2Ti2O7 with pyrochlore structure, and the biphases of (EuxLa1−x)Ti2O7 (x = 0.6, 0.7, and 0.8) consisted of (EuxLa1−x)2Ti2O7 with PLS structure and La3+ doped Eu2Ti2O7 with pyrochlore structure. The effect of A‐site substitution on the properties of La2Ti2O7 was investigated by measuring the dielectric permittivity and loss at different frequencies and temperatures. The highest piezoelectric constant d33 was 2.8 pC/N for (Sm0.1La0.9)Ti2O7.
Efficient Water Purification by Photocatalysis and Rapid Adsorption of Dip‐Coated Metal Foam with Nanostructured Bismuth Vanadate
Authors: Yoon Hyun , Mali Mukund G. , Kim Ha Yong , Al‐Deyab Salem S. , Yoon Sam S.
Published: October 2015

Rapid removal of the organic methylene blue (MB) dye was achieved by simple stirring of highly porous Ni–Fe–Cr–Al metal foam coated with bismuth vanadate (BiVO4). The metal foam was dip‐coated with the BiVO4 solution precursor and annealed for an hour, through which the foam surface was decorated with the highly porous nanostructure, yielding high adsorptivity. This bismuth‐decorated metal foam was characterized by X‐ray diffraction, X‐ray photoelectron, and scanning electron microscopy to elucidate its physical, chemical, and morphological properties. The modeled pollutant, MB, was stirred with the metal foam both in darkness and in light. Complete decolorization was observed for both of these conditions, which indicates that adsorption dominates over photocatalysis; we found that photocatalysis contributed to less than 10% of the purification process. We also demonstrated that it would be possible to recycle the metal foam as many as 20 times, beyond which its purification capability degrades. However, the MB residues on the foam can be removed by simple annealing; thus, in theory the foam can be recycled indefinitely.
Effect of Microstructure of ZnO Nanorod Film on Humidity Sensing
Authors: Chou Kan‐Sen , Lee Chia‐Hsuan , Liu Bo‐Tau
Published: October 2015

In this study, a simple thick‐film humidity sensor was fabricated by coating wet‐synthesized ZnO nanorods on screen‐printing interdigitated electrodes. We investigated the influence of the coating procedure on the microstructure of ZnO nanorod films and thereby on humidity sensing. The experimental results revealed that the specific surface area (SSA) decreased and the average pore size (APS) increased with increasing the sintering time and the number of coating layer. The humidity response depended significantly on the pore properties of the ZnO nanorod films. By virtue of the incipient wetness analysis, it was found that the adsorption of water molecules on the ZnO surface led to the decrease in electrical resistance even though the ZnO was rod like, n‐type semiconductor. While tuning the pore structure of the ZnO nanorod film, the thick‐film humidity sensor might display near‐linear response in the full range of 0%–100% relative humidity (RH).
“Taking charge” of stigma: Treatment seeking alleviates mental illness stigma targeting men
Authors: Moss‐Racusin Corinne A. , Miller Hannah G.
Published: October 2015

This research provided a novel experimental test of mental illness stigma and reactions to treatment seeking decisions for male and female targets. In Experiment 1 (N = 420), robust stigma emerged for targets exhibiting major depressive disorder; they were rated as less likeable, competent, and hirable than comparable normatively functioning targets. These results were unaffected by target gender. In Experiment 2 (N = 322), moderated mediation analysis revealed that a depressed male target embodying masculine stereotypes by seeking professional treatment experienced less stigma than an identical male target who did not seek treatment (and respect mediated this difference). For female targets, treatment seeking did not impact respect or stigma. Implications for the gender gap in treatment seeking and relevant interventions are discussed.
The Montreal Cognitive Assessment: Creating a Crosswalk with the Mini‐Mental State Examination
Authors: Saczynski Jane S. , Inouye Sharon K. , Guess Jamey , Jones Richard N. , Fong Tamara G. , Nemeth Emese , Hodara Ariel , Ngo Long , Marcantonio Edward R.
Published: October 2015

Objectives

To establish Montreal Cognitive Assessment (MoCA) scores that correspond to well‐established cut‐points on the Mini‐Mental State Examination (MMSE).

Design

Cross‐sectional observational study.

Setting

General medical service of a large teaching hospital.

Participants

Individuals aged 75 and older (N = 199; mean age 84, 63% female).

Measurements

The MoCA (range 0–30) and the MMSE (range 0–30) were administered within 2 hours of each other. The Abbreviated MoCA (A‐MoCA; range 0–22) was calculated from the full MoCA. Scores from the three tests were analyzed using equipercentile equating, a statistical method for determining comparable scores on different tests of a similar construct by estimating percentile equivalents.

Results

MoCA scores were lower (mean 19.3 ± 5.8) than MMSE scored (mean 24.1 ± 6.6). Traditional MMSE cut‐points of 27 for mild cognitive impairment and 23 for dementia corresponded to MoCA scores of 23 and 17, respectively.

Conclusion

Scores on the full and abbreviated versions of the MoCA can be linked directly to the MMSE. The MoCA may be more sensitive to changes in cognitive performance at higher levels of functioning.
Clinical importance of median mandibular flexure in oral rehabilitation: a review
Authors: Sivaraman K. , Chopra A. , Venkatesh S. B.
Published: October 2015

The mandible has a property to flex inwards around the mandibular symphysis with change in shape and decrease in mandibular arch width during opening and protrusion of the mandible. The mandibular deformation may range from a few micrometres to more than 1 mm. The movement occurs because of the contraction of lateral pterygoid muscles that pulls mandibular condyles medially and causes a sagittal movement of the posterior segments. This movement of mandible can have a profound influence on prognosis and treatment outcome for various restorative, endodontics, fixed, removable and implant‐related prosthesis. The review unfolds the causes, importance and clinical implications of median mandibular flexure in oral rehabilitation. This review also highlights the appropriate preventive measures and techniques that should be adopted by clinicians to minimise the effect of flexural movement of the jaw during oral rehabilitation. This would not only help clinicians to achieve a good prosthesis with accurate fit and longevity but also maintain the health of the surrounding periodontal or periimplant gingival tissues and bone.
Academic Language in Shared Book Reading: Parent and Teacher Input to Mono‐ and Bilingual Preschoolers
Authors: Aarts Rian , Demir‐Vegter Serpil , Kurvers Jeanne , Henrichs Lotte
Published: October 2015

The current study examined academic language (AL) input of mothers and teachers to 15 monolingual Dutch and 15 bilingual Turkish‐Dutch 4‐ to 6‐year‐old children and its relationships with the children's language development. At two times, shared book reading was videotaped and analyzed for academic features: lexical diversity, syntactic complexity, and abstractness. The AL features in the input of mothers varied considerably among individuals, were strongly intercorrelated and stable over time, and were positively related to children's language skills. For Turkish children, input in Turkish was related to vocabulary in Dutch as well. Compared to mothers, teachers provided input that was more academic. The teachers of the Turkish group used more abstract language but relatively less lexically diverse and syntactically complex talk than the teachers of the Dutch group. By simplifying their language lexically and syntactically, teachers might provide impoverished input to children learning Dutch as a second language.
Differences in oscillatory whistles produced by spinner (Stenella longirostris) and pantropical spotted (Stenella attenuata) dolphins
Authors: Gruden Pina , White Paul R. , Oswald Julie N. , Barkley Yvonne , Cerchio Salvatore , Lammers Marc , Baumann‐Pickering Simone
Published: October 2015

Acoustic recordings of two closely related species, spinner dolphin (Stenella longirostris) and pantropical spotted dolphin (Stenella attenuata), were investigated from four different geographic locations: two in the Central Tropical Pacific, one in the Eastern Tropical Pacific and one in the Indian Ocean. The two delphinid species occur in tropical and warm temperate waters, with overlapping ranges. They produce very similar vocalizations, but at the same time their calls exhibit a certain degree of intraspecific variation among different geographic locations as has been observed in other delphinid species. Oscillatory whistles (whistles with at least two oscillations in their frequency contours) were identified and manually extracted from the recordings. Whistles with four or more maxima (oscillations) occurred only in spinner dolphins and they were present in all geographic regions investigated. In addition, the oscillatory whistles with two and three maxima were significantly more frequent in spinner than in spotted dolphins. The differences in oscillatory whistles for these two species seem to be consistent across study areas and therefore, could be used in addition to other whistle features to help distinguish between them.
Invader disruption of belowground plant mutualisms reduces carbon acquisition and alters allocation patterns in a native forest herb
Authors: Hale Alison N. , Lapointe Line , Kalisz Susan
Published: October 2015

Invasive plants impose novel selection pressures on naïve mutualistic interactions between native plants and their partners. As most plants critically rely on root fungal symbionts (RFSs) for soil resources, invaders that disrupt plant–RFSmutualisms can significantly depress native plant fitness. Here, we investigate the consequences ofRFSmutualism disruption on native plant fitness in a glasshouse experiment with a forest invader that produces known anti‐fungal allelochemicals.

Over 5 months, we regularly applied either green leaves of the allelopathic invaderAlliaria petiolata, a nonsystemic fungicide to simulateA. petiolata's effects, or green leaves of nonallelopathicHesperis matronalis(control) to pots containing the nativeMaianthemum racemosumand itsRFSs. We repeatedly measuredM. racemosumphysiology and harvested plants periodically to assess carbon allocation.

Alliaria petiolataand fungicide treatment effects were indistinguishable: we observed inhibition of theRFSsoil hyphal network and significant reductions inM. racemosumphysiology (photosynthesis, transpiration and conductance) and allocation (carbon storage, root biomass and asexual reproduction) in both treatments relative to the control.

Our findings suggest a general mechanistic hypothesis for local extinction of native species in ecosystems challenged by allelopathic invaders:RFSmutualism disruption drives carbon stress, subsequent declines in native plant vigor, and, if chronic, declines inRFS‐dependent species abundance.
Chemical Manufacturing and Refining Industry Legitimacy: Reflective Management, Trust, Precrisis Communication to Achieve Community Efficacy
Authors: Heath Robert L. , Lee Jaesub
Published: October 2015

Calls for emergency right‐to‐know in the 1980s, and, in the 1990s, risk management planning, motivated U.S. chemical manufacturing and refining industries to operationalize a three‐pronged approach to risk minimization and communication: reflective management to increase legitimacy, operational safety programs to raise trust, and community engagement designed to facilitate citizens’ emergency response efficacy. To assess these management, operational, and communication initiatives, communities (often through Local Emergency Planning Committees) monitored the impact of such programs. In 2012, the fourth phase of a quasi‐longitudinal study was conducted to assess the effectiveness of operational change and community outreach in one bellwether community. This study focuses on legitimacy, trust, and response efficacy to suggest that an industry can earn legitimacy credits by raising its safety and environmental impact standards, by building trust via that change, and by communicating emergency response messages to near residents to raise their response efficacy. As part of its campaign to demonstrate its concern for community safety through research, planning, and implementation of safe operations and viable emergency response systems, this industry uses a simple narrative of risk/emergency response—shelter‐in‐place—communicated by a spokes‐character: Wally Wise Guy.
Homology of the genital sclerites ofMegaloptera (Insecta:Neuropterida) and their phylogenetic relevance
Authors: LIU XINGYUE , LÜ YANAN , ASPÖCK HORST , YANG DING , ASPÖCK ULRIKE
Published: October 2015

The genitalia ofMegaloptera are crucial for taxonomic identification and represent a significant component of characters for phylogenetic interpretation of this order. However, several complex genital structures, especially those related to segments 9 and 11 inMegaloptera, have yet to be subjected to a comprehensive survey of homology. The terminology for genital sclerites has been variously and even incorrectly used by different authors, a fact which could lead to much confusion about character evolution. In this paper, we first present a comprehensive morphological comparison of the sclerites of male and female genital segments in 23 megalopteran genera representing all major lineages ofCorydalinae,Chauliodinae andSialidae. Accordingly, we then provide new interpretations on the homology of the genital sclerites which often appear to be considerably different amongMegaloptera. Based on our new and revised homology assessments, we conclude that: (i) the small to medium‐sized sclerite beneath the ectoprocts in males ofSialidae represents the fused gonocoxites 11; (ii) the male gonocoxites 11 inCorydalidae are largely reduced and are sometimes retained as a small sclerite beneath the anus; (iii) the predominant sternite‐like sclerite of the female abdominal segment 8 represents the fused gonocoxites 8; and (iv) a pair of sclerites amalgamated with the lateral arms of male gonocoxites 10 inChauliodinae is the gonocoxites 9. Furthermore, based on our genital homology assessments, we reconstruct an intergeneric phylogeny including all genera ofMegaloptera using genital characters in a parsimonious analysis to test their phylogenetic relevance. The phylogeny herein recovered is largely congruent with the results from several previous studies, thus underlying the significant phylogenetic relevance of the megalopteran genital sclerites. The present work provides new insights into the evolution of insect genitalia.
Arabidopsis thaliana isoprenyl diphosphate synthases produce the C25 intermediate geranylfarnesyl diphosphate
Authors: Nagel Raimund , Bernholz Carolin , Vranová Eva , Košuth Ján , Bergau Nick , Ludwig Steve , Wessjohann Ludger , Gershenzon Jonathan , Tissier Alain , Schmidt Axel
Published: October 2015

Isoprenyl diphosphate synthases (IDSs) catalyze some of the most basic steps in terpene biosynthesis by producing the prenyl diphosphate precursors of each of the various terpenoid classes. Most plants investigated have distinct enzymes that produce the short‐chain all‐trans (E) prenyl diphosphates geranyl diphosphate (GDP, C10), farnesyl diphosphate (FDP, C15) or geranylgeranyl diphosphate (GGDP, C20). In the genome of Arabidopsis thaliana, 15 trans‐product‐forming IDSs are present. Ten of these have recently been shown to produce GGDP by genetic complementation of a carotenoid pathway engineered into Escherichia coli. When verifying the product pattern of IDSs producing GGDP by a new LC‐MS/MS procedure, we found that five of these IDSs produce geranylfarnesyl diphosphate (GFDP, C25) instead of GGDP as their major product in enzyme assays performed in vitro. Over‐expression of one of the GFDP synthases in A. thaliana confirmed the production of GFDP in vivo. Enzyme assays with A. thaliana protein extracts from roots but not other organs showed formation of GFDP. Furthermore, GFDP itself was detected in root extracts. Subcellular localization studies in leaves indicated that four of the GFDP synthases were targeted to the plastoglobules of the chloroplast and one was targeted to the mitochondria. Sequence comparison and mutational studies showed that the size of the R group of the 5th amino acid residue N‐terminal to the first aspartate‐rich motif is responsible for C25 versus C20 product formation, with smaller R groups (Ala and Ser) resulting in GGDP (C20) as a product and a larger R group (Met) resulting in GFDP (C25).
Actin, Membrane Trafficking and the Control of Prion Induction, Propagation and Transmission in Yeast
Authors: Moosavi Behrooz , Mousavi Bibimaryam , Yang Guang‐Fu
Published: October 2015

The model eukaryotic yeast Saccharomyces cerevisiae has proven a useful model system in which prion biogenesis and elimination are studied. Several yeast prions exist in budding yeast and a number of studies now suggest that these alternate protein conformations may play important roles in the cell. During the last few years cellular factors affecting prion induction, propagation and elimination have been identified. Amongst these, proteins involved in the regulation of the actin cytoskeleton and dynamic membrane processes such as endocytosis have been found to play a critical role not only in facilitating de novo prion formation but also in prion propagation. Here we briefly review prion formation and maintenance with special attention given to the cellular processes that require the functionality of the actin cytoskeleton.
Living in a Makeshift World? Mobility, Temporariness, and Everyday Life in Indonesia
Authors: Kloos David
Published: October 2015

This article uses material from “Recording the Future: An Audiovisual Archive of Everyday Life in Indonesia in the 21st Century” (RtF) in order to explore the creative and emotional processes through which ordinary Indonesians try to make places “their own.” Employing the notion of “makeshift” as an analytical category, I analyze how modes of improvisation and senses of temporariness are visualized in the RtF archive. By doing so, I centralize the everyday conditions and experiences of a seemingly amorphous but increasingly significant class of Indonesian domestic migrants in search of an income and a place to live. Integrating visual materials and textual analysis, I argue that these experiences are based, on the one hand, on a willingness to leave and the ability to adapt and, on the other hand, on a fundamental desire for a stable and regular life.
Suffering Bodies and Scenes of Confrontation: The Art and Politics of Representing Structural Violence
Authors: Stone Livia K.
Published: October 2015

This article argues that a visual focus on suffering bodies can obscure the power relationships that result in inequality and injustice through (1) obscuring the mechanisms and perpetrators of violence, (2) not disrupting dominant conceptual frameworks, and (3) not leaving room for solutions. I use a corpus of films made about and by a Mexican social movement in San Salvador Atenco to ask a practical question: How might we represent issues of structural violence without focusing on images of suffering and victimization? The solution that these films present is a focus on what I call “scenes of confrontation.”
The invariant tag isn't it in Asian Englishes
Authors: PARVIAINEN HANNA
Published: October 2015

The aim of this paper is to conduct a quantitative corpus‐based analysis in order to detect how frequently the invariant tag isn't it is used in the English varieties of India, Singapore, Hong Kong and the Philippines. American and British English were added to the study for point of reference. The data were obtained from the International Corpus of English for all other varieties except for spoken American English, for which the Santa Barbara Corpus of Spoken American English was used. The results indicate that the use of isn't it as an invariant tag appears almost solely in spoken language and the highest frequencies can be found in Indian English, followed by Singaporean English, Hong Kong English and Philippine English.
A description of the Yunnan English accent
Authors: AO RAN , LOW EE LING
Published: October 2015

This paper presents findings of an acoustic investigation of monophthong vowels produced by learners of English from Yunnan, China. Speech data for the present study were collected from 15 participants comprising five Han Chinese English majors, five Han Chinese non‐English majors and five Yi minority ethnic English majors. The findings show that the three groups share more differences than similarities in terms of vowel duration but not in terms of vowel quality though the results of Euclidean distance show that the Han Chinese English majors and the Han Chinese non‐English majors are different from the Yi minority ethnic English majors. Results of standard deviation reveal that the Yi minority ethnic English majors have the lowest inter‐speaker variability, followed by the Han Chinese English majors and the Han Chinese non‐English majors.
Each‐step activation of oxidative phosphorylation is necessary to explain muscle metabolic kinetic responses to exercise and recovery in humans
Authors: Korzeniewski Bernard , Rossiter Harry B.
Published: October 2015

Key points

The basic control mechanisms of oxidative phosphorylation (OXPHOS) and glycolysis during work transitions in human skeletal muscle are still a matter of debate.

We used simulations of skeletal muscle bioenergetics to identify key system features that contribute to this debate, by comparing kinetic model outputs with experimental human data, including phosphocreatine, pH, pulmonary oxygen uptake and fluxes of ATP production by OXPHOS (vOX), anaerobic glycolysis and creatine kinase in moderate and severe intensity exercise transitions.

We found that each‐step activation of particular OXPHOS complexes, NADH supply and glycolysis, and strong (third‐order) glycolytic inhibition by protons was required to reproduce observed phosphocreatine, pH and vOX kinetics during exercise.

A slow decay of each‐step activation during recovery, which was slowed further following severe exercise, was necessary to reproduce the experimental findings.

Well‐tested computer models offer new insight in the control of the human skeletal muscle bioenergetic system during physical exercise.

To better understand muscle bioenergetic regulation, a previously‐developed model of the skeletal muscle cell bioenergetic system was used to simulate the influence of: (1) each‐step activation (ESA) of NADH supply (including glycolysis) and oxidative phosphorylation (OXPHOS) complexes and (2) glycolytic inhibition by protons on the kinetics of ATP synthesis from OXPHOS, anaerobic glycolysis and creatine kinase. Simulations were fitted to previously published experimental data of ATP production fluxes and metabolite concentrations during moderate and severe intensity exercise transitions in bilateral knee extension in humans. Overall, the computer simulations agreed well with experimental results. Specifically, a large (>5‐fold) direct activation of all OXPHOS complexes was required to simulate measured phosphocreatine and OXPHOS responses to both moderate and severe intensity exercise. In addition, slow decay of ESA was required to fit phosphocreatine recovery kinetics, and the time constant of ESA decay was slower following severe (180 s) than moderate (90 s) exercise. Additionally, a strong inhibition of (anaerobic) glycolysis by protons (glycolytic rate inversely proportional to the cube of proton concentration) provided the best fit to the experimental pH kinetics, and may contribute to the progressive increase in oxidative ATP supply during acidifying contractions. During severe‐intensity exercise, an ‘additional’ ATP usage (a 27% increase at 8 min, above the initial ATP supply) was necessary to explain the observed slow component. Thus, parallel activation of ATP usage and ATP supply (ESA), and a strong inhibition of ATP supply by anaerobic glycolysis, were necessary to simulate the kinetics of muscle bioenergetics observed in humans.
Experimental Investigation of a Lab-Scale, Cross-Flow Grain Dryer for Testing of Drying Efficiency and Characteristic Profiles of a Packed Bed
Authors: Suess Taylor N. , Twedt Michael P. , Gent Stephen P.
Published: October 2015

This study investigates the drying mechanisms of corn when it is exposed to air at elevated temperature and velocity within a cross-flow packed bed dryer. A highly-instrumented laboratory-scale experimental test dryer was constructed to batch-dry samples of 0.03 m3 (1 ft3) of high moisture corn. This is achieved using a perforated wall drying chamber with forced air at temperatures ranging from 180–240°F. The high temperature, high velocity air entering the column is supplied by a variable speed fan and a variable Wattage electric heating coil through a 0.09 m2 (1 ft2) square air duct. This device is able to precisely control the drying air temperate and flow rate, while also measuring the temperature and humidity of the air exiting the dryer. In creating and instrumenting this apparatus, tests were performed to analyze both energy use and drying rate to determine the operating conditions that find a balance between energy and time requirements for moisture removal. This study used a variety of supply air temperatures and air flow rates in drying samples of corn at two initial moisture contents (19%MC and 24%MC) to 15%MC. This is done to determine if there are notable differences in energy requirements (Btu/pound water removed) between different operating conditions. This study determined that corn undergoes a significant pre-heating process before peak drying efficiency is achieved. Current grain dryer designs should focus the most energy just after that pre-heating process for highest overall efficiencies. Additionally, this study found an inverse relationship between dry time and energy efficiency, which showed that an optimum balance between those two factors should be identified.
A Dimensionality-Reduced First Order Method for Industrial Optimization: A Case Study in Renewable Energy Technologies
Authors: Hajimirza Shima
Published: October 2015

We propose and study a dimensionality-reduced first order method for solving complex optimization problems of high-dimensional search space. We demonstrate that the proposed method is very efficient in design problems where the computational bottleneck is mostly due to the time-consuming nature of the forward problem in contrast to the complexity of the function behavior in the search space or other computational overheads. Many industrial problems are of this nature including design problems based on back testing or simulation of an evolutionary equation or a dynamic system in time, frequency or other (hybrid) domains, such as Electromagnetic, Quantum equations, Navier-Stokes PDEs, etc. The premise of efficiency improvement in the proposed framework is a better modelling and utilization of the complexity distribution among the components of an inverse design problem. As a particular case study, we list some of the existing optimization problems related to energy production, distribution and utilization at the industrial level. We briefly overview the different complexity components of these problems at a high level, and make suggestions as what industrial problems can be facilitated through the proposed framework.
Design and Testing of a Separate Sensible and Latent Cooling Packaged Terminal Air Conditioning Unit
Authors: Alabdulkarem Abdullah , Cristiano Michael , Hwang Yunho , Radermacher Reinhard
Published: October 2015

Packaged terminal air conditioning (PTAC) systems are typically utilized for space heating and cooling in hotels and apartment buildings. However, they cool the air to low temperature for dehumidification and some reheating may be required to resolve overcooling. A prototype of a solid desiccant wheel assisted separate sensible and latent cooling (SSLC) PTAC system was designed and constructed, which has a cooling capacity of 3.5 kW. The heat exchangers and vapor compression cycle were modeled in in-house software, CoilDesigner and VapCyc. The modeling results show improvement in the coefficient of performance from 3.12 to 4.05 or 30%. Cost study was conducted to evaluate the economics of SSLC PTAC units within the U.S. climate conditions. The study shows the payback period for the national average could be as low as 2 years. The system was experimentally tested and its performance was not as expected due to some design challenges. This paper highlights the lessons learned from the modeling and experimental work and discusses the economic analysis in addition to future design improvements and system optimization.
Multi-Physics Energy Approach and Demonstration Facility
Authors: Pollman Anthony G. , Gannon Anthony J.
Published: October 2015

A methodology to investigate the generation, transport and storage of energy based on a multi-physics approach, tied to the end use application, is presented. Often little or no consideration is given to the end use or desired product of the energy used. Current energy generation, transport and storage are dominated heavily by a few large sectors, notably electricity and hydrocarbons. These are very effective and practical systems that facilitate the delivery of vast amounts of energy. It is then not surprising that most strategies for renewable energy generation and storage revolve around this centralized model in some way. In larger scale generation, power is usually fed onto the electrical grid with a current challenge being grid stabilization with increasing penetration of intermittent renewable resources. In small grid-independent system a mix of battery and hydrocarbon storage are often used to keep a micro-grid available for various end use applications.

A paradigm shift in the thinking and design of energy systems based on the required end use or product is needed. The philosophy and motivation that lead to the consideration of this new approach are outlined in this article. Following this a summary of a methodical approach to developing the most energy and cost-effective solution to general processes by considering their end-use physics is presented. Examples of innovative energy generation, storage, and transport solutions based on the multi-physics approach are then outlined. Finally, a brief description of the Multi-physics Renewable Energy Lab (MPREL), a demonstration facility based on the approach and currently under construction at the Naval Postgraduate School, is given.
24 Hour Step Ahead Wind Speed / Wind Power Prediction Using a Novel Kalman Filter Bank Prediction Estimator
Authors: Lynch Conor , O’Mahony Michael J. , Guinee Richard A.
Published: October 2015

This paper presents a new approach allowing Numerical Weather Prediction (NWP) grid model forecasting to be applied to a desired “sub-grid” location. It permits observations from a NWP model using a novel bank of 24 Kalman Filters (KFs) operating simultaneously to accurately predict the wind speed (Zt) 24 hours ahead for a campus based wind turbine at Cork Institute of Technology (CIT) at 20m above sea level (asl) at sub grid location. The NWP model outputs wind speed predictions (mt) for Cork Airport at 152m asl (2.5km distant from CIT) at grid level. The Kalman Filter (KF), acting as a post processing tool with a moving time averaging window, derives a 24 hour ahead predicted wind speed schedule for CIT by applying a wind speed bias model polynomial to map and filter the wind speed bias offset between the two locations. To ensure a robust model, with good modelling and error noise disturbance rejection capabilities inclusive of model offsets [1], the accuracy of the model has been investigated using a particularly turbulent wind data set for December 2013 [2].

It is shown that a 4th order polynomial adaptive wind speed model bias remover is the optimum choice to employ in conjunction with the KF which uses a 3 point a priori moving window averager to adequately eliminate systematic error. The application of a KF to wind speed prediction is implemented in MATLAB software and results are provided in this paper to demonstrate the accuracy and fidelity of the procedure. Hypothesis testing along with statistical analysis has returned wind velocity prediction estimates that demonstrate the accuracy of the KF estimator. This also provides confidence enhancement of the polynomial model choice as a suitable wind velocity bias eliminator. The accuracy of the hourly wind velocity estimate are of strategic importance in wind power prediction where installed wind turbine scheduling is an issue for cost effective electrical network operation with a consequent beneficial economic return on wind generator capital investment.
Modeling of a Solar Receiver for Superheating Sulfuric Acid
Authors: Lapp Justin L. , Guerra-Niehoff Alejandro , Streber Hans-Peter , Thomey Dennis , Roeb Martin , Sattler Christian
Published: October 2015

A volumetric solar receiver for superheating evaporated sulfuric acid is developed as part of a 100kW pilot plant for the Hybrid Sulfur Cycle. The receiver, which uses silicon carbide foam as a heat transfer medium, heats evaporated sulfuric acid using concentrated solar energy to temperatures up to 1000 °C, which are required for the downstream catalytic reaction to split sulfur trioxide into oxygen and sulfur dioxide. Multiple approaches to modeling and analysis of the receiver are performed to design the prototype. Focused numerical modeling and thermodynamic analysis are applied to answer individual design and performance questions. Numerical simulations focused on fluid flow are used to determine the best arrangement of inlets, while thermodynamic analysis is used to evaluate the optimal dimensions and operating parameters. Finally a numerical fluid mechanics and heat transfer model is used to predict the temperature field within the receiver. Important lessons from the modeling efforts are given and their impacts on the design of a prototype are discussed.
Design, Analysis and Construction of a Low Cost Air Heater for Residential Uses
Authors: Weber Bernd , Valdespino Jessica A. Fernández , García David , Durán M. Dolores , Cienfuegos Iván G. Martínez , Rincón Eduardo
Published: October 2015

In order to meet global challenges to reduce greenhouse gas emissions, the implementation of solar systems for residential purposes is an emergent task. Commonly liquid-based solar systems are used to heat up shower and pool water. More recently space heating systems have become part of sustainable buildings. An alternative could be a solar system that uses air as energy carrier. This study analyses the retrofit of such a system into a 40-year-old building. Starting from the analysis of the energy demand of a selected room, a solar air heater was designed, simulated and evaluated experimentally. The solar efficiency of the constructed collector reached 60%.
A Methodology for Determining Optimum Solar Tower Plant Configurations and Operating Strategies to Maximize Profits Based on Hourly Electricity Market Prices and Tariffs
Authors: Guédez Rafael , Topel Monika , Buezas Inés Conde , Ferragut Francisco , Callaba Irene , Spelling James , Hassar Zhor , Pérez-Segarra Carlos David , Laumert Björn
Published: October 2015

The present study analyses the influence that market conditions have on determining optimum molten salt solar tower plants with storage that maximize profits (in terms of plant configuration, sizing and operation) for a location in South Africa. Three different scenarios based on incentive programs and local wholesale electricity prices are considered. A multi-objective optimization modeling approach was followed, showing the trade-off curves between minimizing investment and maximizing profits when varying critical sizerelated parameters (such as nameplate capacity, solar multiple and storage capacity) together with power-cycle design and operating specifications including dynamic start-up curves and different storage dispatchability strategies. Results are shown by means of a comparative analysis between optimal plants found for each scenario, highlighting the value that storage has under the current two-tier tariff scheme, and the relevance of designing a suitable policy for technology development. Lastly, a final analysis is performed with regards of the indicators used for economic evaluation of power plants, by comparing the differences between optimum designs found when using the levelized cost of electricity solely as performance indicator instead of cash-flows and profit-based indicators, such as the internal rate of return.
Optical Analysis of a New Point Focus Fresnel Concentrator
Authors: Al-Ansary Hany , Alaqel Shaker , Djajadiwinata Eldwin , Mohammed Abdullah
Published: October 2015

This study describes preliminary optical analysis performed regarding a new collector called the Point Focus Fresnel Concentrator (PFFC). This collector combines the concepts of the linear Fresnel collector and central receiver systems to form a new concept of a focal point Fresnel concentrator with a dual-axis sun tracking system. It concentrates direct solar radiation using a number of flat mirrors positioned over a rotating frame. The frame tracks the sun in the azimuth direction, while each row of mirrors tracks the sun in the elevation direction, thereby allowing sunlight to be concentrated on the same point above the collector throughout the day. PFFC is considered suitable for a number of applications, such as power generation by concentrating photovoltaics (CPV) and Stirling engines, and process heat applications. In this study, the first attempt to characterize the optical performance of the collector is made. A prototype of the collector has already been built on the campus of King Saud University. It has a total footprint of 9 m2, and includes 900 mirrors, each of which is 7 cm × 7 cm. The receiver has a diameter of 10 cm. Optical performance is studied by ray tracing methods to obtain flux maps and intercept factors of the receiver. Results show that the average concentration ratio is in the order of 220 to 300 suns when mirrors with a 6-mrad optical error are used. For the same mirrors, the highest attainable average intercept factor (0.674) occurs in the winter due to the low particle loading in the atmosphere. When the optical error is reduced to 2 mrad, the average concentration ratio increases to 290 to 400 suns, and the average intercept factor increases to 0.892. In any case, if the current design of PFFC is to be used in conjunction with CPV, a secondary concentrator would be needed to achieve required concentration ratios in the order of 500 suns.
Investigation of Fast Pyrolysis of Brassica Carinata in an Auger Type Reactor
Authors: Sonnek William D. , Gent Stephen P. , Michna Gregory J.
Published: October 2015

Fast pyrolysis is one method of creating bio-oil from biomass such as native prairie grasses, corn stover, and other organic commercial and industrial byproducts. In this study, fast pyrolysis of Brassica carinata meal, or simply carinata meal, was performed in an auger-type reactor. The bio-oil produced in the reactor was collected and analyzed to determine the effects of reactor and condenser temperatures on the properties of the bio-oil produced. Five reactor temperatures and two condenser temperatures were investigated in this research. The rheological properties of the bio-oil samples were analyzed, water content was determined with the Karl Fisher method, energy content was measured with a bomb calorimeter, and acidity was determined using a total acid titration test. The aging characteristics of the bio-oil were also investigated at seven days, fourteen days, and twenty-eight days after the oil was created to determine what effect, if any, time had on the its properties. Preliminary results indicate that any reactor temperature above 500°C produces bio-oils of similar composition, although with changes in yield. In addition, the short-term aging results of the bio-oils have shown insignificant changes in total acid number, water content, and energy content.
Numerical Radiation Exchange in Rectangular Micro- and Mini-Channels Using the Monte Carlo Method
Authors: Amundson Thomas R. , Webb Rebecca N.
Published: October 2015

The addition of appropriately shaped macroscale structures to a surface results in a directionally selective surface capable of high absorption of direct solar radiation and low hemispherical emission. This work investigates the effect of adding sub-macroscale structures to a smooth surface on net radiative heat transfer. The Monte Carlo method was used to characterize the net radiative heat transfer of rectangular micro- and mini-channels. The effects of varying the aspect ratio, surface absorptivity, and incident angle were determined. The effect of diffuse and specular reflections was also examined. For a diffuse surface, as the absorptivity increases so does the net heat transfer however, higher incident angles result in lower net heat transfer. For a specular surface, net heat transfer increases with both incidence angle and aspect ratio. In general, deeper channels increase net heat transfer. The effect of channel periodicity was also examined. In general, shorter periods increase net heat transfer when normalized by system length.
Thermodynamic Analysis of Non-Stoichiometric Perovskites as a Heat Transfer Fluid for Thermochemical Energy Storage in Concentrated Solar Power
Authors: Albrecht Kevin J. , Braun Robert J.
Published: October 2015

The implementation of efficient and cost effective thermal energy storage in concentrated solar power (CSP) applications is crucial to the wide spread adoption of the technology. The current push to high-temperature receivers enabling the use of advanced power cycles has identified solid particle receivers as a desired technology. A potential way of increasing the specific energy storage of solid particles while simultaneously reducing plant component size is to implement thermochemical energy storage (TCES) through the use of non-stoichiometric perovskite oxides. Materials such as strontium-doped lanthanum cobalt ferrites (LSCF) have been shown to have significant reducibility when cycling temperature and oxygen partial pressure of the environment [1]. The combined reducibility and heat of the oxidation and reduction reactions with the sensible change in temperature of the material leads to specific energy storage values approaching 700 kJ kg−1. A potential thermochemical energy storage system configuration and modeling strategy is reported on, leading to a parametric study of critical operating parameters on the TCES subsystem performance. For the LSCF material operating between 500 and 900°C with oxygen partial pressure swings from ambient to 0.0001 bar, system efficiencies of 68.6% based on the net thermal energy delivered to the power cycle relative to the incident solar flux on the receiver and auxiliary power requirements, with specific energy storage of 686 kJ kg−1 are predicted. Alternatively, only cycling the temperature between 500 and 900°C without oxygen partial pressure swings results in TCES subsystem efficiencies up to 76.3% with specific energy storage of 533 kJ kg−1.
Tri-Sol (Building-Integrated, Three-in-One Solar) Technology Development
Authors: Gorthala Ravi
Published: October 2015

A unique solar technology that can be building-integrated, which harnesses both visible and infrared spectrums of solar radiation, utilizes direct and diffuse radiation to produce electricity and hot water, and delivers daylight, has been conceptualized. This technology is a three-in-one (named Tri-Sol), low/medium-concentration, building-integrated, skylight system for commercial buildings. However, this technology can be utilized for building facades and other building envelope components. A key component of the technology is linear Fresnel lenses. These lenses can be designed to be thin and light-weight. Sunlight, concentrated by the linear Fresnel lenses with a low-cost single axis tracker, focuses on a high-efficiency, thin Photo Voltaic (PV) strip that is in contact with a thermal absorber. Electricity produced by PV strips can be processed and distributed from an electric power management system. The thermal absorber houses a sealed heat pipe for cooling the PV strip and producing hot water. The water-cooled condenser section of the heat pipe is external to the skylight so that there is no issue of water leakage through the skylight. Hot water produced can be used for end-use, space heating, or absorption cooling. All diffuse light that cannot be concentrated by Fresnel lenses is delivered into the building interior space.

A pre-prototype of Tri-Sol technology was designed and built at University of New Haven (UNH). Solar Testing and Training Laboratory (STTL) at UNH houses solar thermal collector equipment with a capability to perform Solar Rating and Certification Corporation (SRCC) tests. The Tri-Sol module was mounted on the SRCC test equipment at UNH and was tested outdoors to identify any issues or design enhancements.
Impacts of Industrial Baseline Errors on Costs and Social Welfare in the Demand Side Management of Day-Ahead Wholesale Markets
Authors: Jiang Bo , Farid Amro M. , Youcef-Toumi Kamal
Published: October 2015

Demand Side Management (DSM) has been recognized for its potential to counteract the intermittent nature of renewable energy, increase system efficiency, and reduce system costs. While the popular approach among academia adopts a social welfare maximization formulation, the industrial practice in the United States electricity market compensates customers according to their load reduction from a predefined electricity consumption baseline that would have occurred without DSM. This paper is an extension of a previous paper studying the differences between the industrial & academic approach to dispatching demands. In the previous paper, the comparison of the two models showed that while the social welfare model uses a stochastic net load composed of two terms, the industrial DSM model uses a stochastic net load composed of three terms including the additional baseline term. That work showed that the academic and industrial optimization method have the same dispatch result in the absence of baseline errors given the proper reconciliation of their respective cost functions. DSM participants, however, and very much unfortunately, are likely to manipulate the baseline in order to receive greater financial compensation. This paper now seeks to study the impacts of erroneous industrial baselines in a day-ahead wholesale market context. Using the same system configuration and mathematical formalism, the industrial model is compared to the social welfare model. The erroneous baseline is shown to result in a different and more importantly costlier dispatch. It is also likely to require more control activity in subsequent layers of enterprise control. Thus an erroneous baseline is likely to increase system costs and overestimate the potential for social welfare improvements.