bluuebunny/crossref_metadata_2025 huggingface dataset:
Successful sleeve lobectomy of pediatric inflammatory myofibroblastic tumor
Authors: Genchellac Hakan , Kirici Mehmet Yadigar , Basaran Umit Nusret , Karamustafaoglu Yekta Altemur , Cagli Bekir , Tastekin Ebru
Published: November 2016

Inflammatory myofibroblastic tumor (IMT) is an uncommon solid tumor that was originally described in the lung. A 4‐year‐old girl was admitted to hospital with urticarial rash. On chest radiographs, an opacity was seen in the inferior zone of the left lung, and computed tomography showed a mass in the left lower lobe. Left lower sleeve lobectomy was performed, and the diagnosis was confirmed as IMT. Sleeve resection is the best option in lesions located in the mainstem bronchus or secondary carina. Herein, we present a rare case of IMT of the lung that was successfully treated with sleeve lobectomy. There have been fewer than 15 childhood cases of IMT reported in the literature, and the present 4‐year‐old patient is one of the youngest.
Successful low‐dose radiotherapy treatment for Kasabach–Merritt syndrome
Authors: Yamamoto Shohei , Akiyama Kosuke , Kaneko Ryota , Hayashi Mayumi , Toyama Daisuke , Isoyama Keiichi
Published: November 2016

Kasabach–Merritt syndrome (KMS) is characterized by hemangioma associated with life‐threatening thrombocytopenia, and is a consumptive coagulopathy. Although treatments available include corticosteroids, α‐interferon, vincristine, and surgery, response may be unsatisfactory, and the mortality rate remains at approximately 30%. Although radiotherapy has been used effectively for KMS, it may cause growth retardation and secondary malignancy. We report a case of KMS in which hemangioma of the left thigh was successfully treated with low‐dose radiotherapy (6 Gy in six fractions, weekly) after failure of corticosteroid therapy. No significant late effects due to the radiotherapy were noted at 5 year follow up. Thus, low‐dose radiotherapy remains an important treatment method for KMS when patients fail to respond to other treatments.
Conservative treatment of massive hemothorax in a girl with neuroblastoma
Authors: Shiokawa Naohiro , Okamoto Yasuhiro , Kodama Yuichi , Nishikawa Takuro , Tanabe Takayuki , Mukai Motoi , Yoshioka Takako , Kawano Yoshifumi
Published: November 2016

We report the case of a 1‐year‐old girl with stage 4 neuroblastoma who developed massive hemothorax due to tumor invasion before treatment. She presented with tachypnea, worsening anemia, and oxygen desaturation. Hemothorax was diagnosed based on chest radiography, ultrasonography, and diagnostic thoracic puncture results. High neuron‐specific enolase, vanillylmandelic acid, and homovanillic acid as well as computed tomography strongly supported a diagnosis of neuroblastoma. Chemotherapy along with intermittent puncture drainage, oxygen, and blood transfusion reduced the accumulated blood, and hemothorax disappeared within 1 week. Thus, it is possible to avoid invasive treatment for massive hemothorax by initiating chemotherapy for chemosensitive solid tumors, including neuroblastoma.
Low cardiac output thyroid storm in a girl with Graves’ disease
Authors: Chantra Marut , Limsuwan Alisa , Mahachoklertwattana Pat
Published: November 2016

A 15‐year‐old girl with Graves’ disease presented with hypotension after methimazole and propranolol were re‐started for hyperthyroidism. She was found to have pulmonary artery hypertension resulting in obstructive shock. Thyroid storm was diagnosed according to Burch and Wartofsky score. She was promptly treated with anti‐thyroid drugs, inorganic iodide, corticosteroid, and respiratory support. Pulmonary hypertension was treated with inhaled nitric oxide until the clinical status improved. Propranolol was withdrawn due to poor cardiac function. We herein present a unique case of a difficult‐to‐treat Graves’ disease presenting with severe pulmonary hypertension resulting in low cardiac output thyroid storm.
Skin cancer risk education in pediatric solid organ transplant patients: an evaluation of knowledge, behavior, and perceptions over time
Authors: Coughlin Carrie C. , Pérez Maria , Kumar Monique G. , Jeffe Donna B. , Bayliss Susan J. , Sternhell‐Blackwell Kara
Published: November 2016

Skin cancer risk is elevated in solid OTRs. Studies of skin cancer awareness and sun‐protection behaviors in pOTRs have not been reported. We measured effects over time of a multimodal educational intervention on knowledge of sun‐protection practices and skin cancer risk, engagement in sun‐protection behaviors, and self‐efficacy and perceived barriers to photoprotection in pOTRs, their guardians, and a comparison group of children and guardians. Knowledge about skin cancer risk increased in pOTRs and their guardians (P≤.01) and frequency of pOTRs’ sun‐protection behaviors reported by pOTRs and their guardians also improved.
Contrast Estimation for Parametric Stationary Determinantal Point Processes
Authors: Biscio Christophe Ange Napoléon , Lavancier Frédéric
Published: November 2016

We study minimum contrast estimation for parametric stationary determinantal point processes. These processes form a useful class of models for repulsive (or regular, or inhibitive) point patterns and are already applied in numerous statistical applications. Our main focus is on minimum contrast methods based on the Ripley's K‐function or on the pair correlation function. Strong consistency and asymptotic normality of theses procedures are proved under general conditions that only concern the existence of the process and its regularity with respect to the parameters. A key ingredient of the proofs is the recently established Brillinger mixing property of stationary determinantal point processes. This work may be viewed as a complement to the study of Y. Guan and M. Sherman who establish the same kind of asymptotic properties for a large class of Cox processes, which in turn are models for clustering (or aggregation).
Efficacy of transfusion with fresh‐frozen plasma:red blood cell concentrate ratio of 1 or more for amniotic fluid embolism with coagulopathy: a case–control study
Authors: Tanaka Hiroaki , Katsuragi Shinji , Osato Kazuhiro , Hasegawa Junichi , Nakata Masahiko , Murakoshi Takeshi , Yoshimatsu Jun , Sekizawa Akihiko , Kanayama Naohiro , Ishiwata Isamu , Ikeda Tomoaki
Published: November 2016

BACKGROUND

The Japan Association of Obstetricians and Gynecologists (JAOG) recommends transfusion with a fresh‐frozen plasma (FFP):red blood cell (RBC) ratio of 1 or more in postpartum hemorrhage. However, no global consensus exists concerning this, and little is known regarding the impact of FFP:RBC ratio on maternal mortality. This study evaluates the efficacy of transfusion with FFP:RBC ratio of 1 or more for amniotic fluid embolism (AFE) with coagulopathy.

STUDY DESIGN AND METHODS

The Maternal Death Exploratory Committee, established by the JAOG, conducted this retrospective nationwide case–control study in Japan. Women with AFE and coagulopathy were included in the study and were stratified into survival and death groups. Obstetric variables and therapy methods (hysterectomy, uterine artery embolism, and transfusion with FFP:RBC ratio ≥ 1) were compared between the survival and death groups.

RESULTS

A total of 54 women had AFE and coagulopathy (death group, n = 22; survival group, n = 32). Only nine (40.9%) women in the death group were transfused with FFP:RBC ratio of 1 or more, whereas 29 (90.6%) women in the survival group were transfused with FFP:RBC ratio of 1 or more. FFP:RBC ratio of 1 or more was found to be associated with better survival rate (adjusted odds ratio, 28.32; 95% confidence interval, 4.26‐188.37). No difference was found in obstetric variables, hysterectomy, and uterine artery embolism between survival and death groups.

CONCLUSION

Transfusion with FFP:RBC ratio of 1 or more is associated with higher survival rate in women with AFE with coagulopathy.
Understanding the Relationship between Inflation and Growth: A Wavelet Transformation Approach in the Case of Bangladesh
Authors: Uddin Gazi Salah , Muzaffar Ahmed Taneem , Arouri Mohamed , Sjö Bo
Published: November 2016

This paper re‐examines the relationship between inflation and economic growth in developing countries. Both the theoretical and the empirical literature are extremely divided on this issue. We apply a relatively new empirical technique – the continuous wavelet transform – to Bangladesh. Bangladesh is of interest because of its remarkable economic growth and poverty reduction during the last 30 years in combination with, for a developing country, a controlled inflation. The wavelet analysis is a contribution because it displays how the correlation and the lead–lag structure between variables change over timescales, taking into account that growth and inflation can follow several different cycles. Comovements between variables are generally studied in the time domain. Results from studies in the time‐domain study can be sensitive to the frequency of observations. On the other hand, studies in the frequency domain are not easily translated into time domains that can be associated with economic policies. The wavelet methodology finds a balance between time and frequency domains. Our study finds that growth Granger causes inflation at all frequency scales, starting from the short run to the very long run. Inflation, on the other hand, Granger causes growth in the long run but not in the short run. This result has implications for Bangladesh, and as such for similar developing countries, where some policymakers believe that inflation must be kept at very low levels for sustained economic growth.
Laboratory tests for diagnosing and monitoring canine leishmaniasis
Authors: Paltrinieri Saverio , Gradoni Luigi , Roura Xavier , Zatelli Andrea , Zini Eric
Published: November 2016

Although several reviews on canine leishmaniasis have been published, none thoroughly described clinicopathologic abnormalities and their clinical usefulness. The aim of this review was to provide information concerning current diagnostic tests relevant for clinical pathologists and from a practical perspective. Specifically, in canine leishmaniasis, nonregenerative normocytic normochromic anemia, thrombocytopenia, or leukogram changes may be present. Clinical chemistry and urinalysis may indicate renal dysfunction (azotemia, decreased urine specific gravity, proteinuria) and an inflammatory/immune response (increased acute phase proteins [APP] or α2‐ and/or γ‐globulins). Although a potential gammopathy is usually polyclonal, it may also appear oligo‐ or monoclonal, especially in dogs coinfected by other vector‐borne pathogens. When lesions are accessible to fine‐needle aspiration (lymphoadenomegaly, nodular lesions, joint swelling), cytology is strongly advised, as the presence of Leishmania amastigotes in a pattern of pyogranulomatous inflammation or lymphoplasmacytic hyperplasia is diagnostic. If the cytologic pattern is inconclusive, the parasite should be identified by histology/immunohistochemistry or PCR on surgical biopsies. Alternatively, cytology and PCR may be performed on bone marrow samples where amastigotes, along with erythroid hypoplasia, myeloid hyperplasia, plasmacytosis, or secondary dysmyelopoiesis can be observed. Dogs with overt leishmaniasis generally have high antibody titers, while low titers predominate in immunologically resistant infected dogs or in exposed dogs with no parasite confirmation. Quantitative serology is recommended in clinically suspect dogs as high‐titer antibodies titers may confirm the clinical diagnosis. In confirmed and treated dogs, renal function and inflammatory/immune response variables should be periodically monitored.
A remark on fullness of some group measure space von Neumann algebras
Authors: Ozawa Narutaka
Published: November 2016

Recently Houdayer and Isono have proved, among other things, that every biexact group $\unicode[STIX]{x1D6E4}$ has the property that for any non-singular strongly ergodic essentially free action $\unicode[STIX]{x1D6E4}\curvearrowright (X,\unicode[STIX]{x1D707})$ on a standard measure space, the group measure space von Neumann algebra $\unicode[STIX]{x1D6E4}\ltimes L^{\infty }(X)$ is full. In this paper, we prove the same property for a wider class of groups, notably including $\text{SL}(3,\mathbb{Z})$. We also prove that for any connected simple Lie group $G$ with finite center, any lattice $\unicode[STIX]{x1D6E4}\leqslant G$, and any closed non-amenable subgroup $H\leqslant G$, the non-singular action $\unicode[STIX]{x1D6E4}\curvearrowright G/H$ is strongly ergodic and the von Neumann factor $\unicode[STIX]{x1D6E4}\ltimes L^{\infty }(G/H)$ is full.
Experimental Study of a Vibrating Disk Submerged in a Fluid-Filled Tank and Confined With a Nonrigid Cover
Authors: Valentín David , Presas Alexandre , Egusquiza Eduard , Valero Carme , Egusquiza Mònica
Published: November 2016

Determining the dynamic response of submerged and confined disklike structures is of interest in engineering applications, such as in hydraulic turbine runners. This dynamic response is heavily affected by the added mass and damping as well as the proximity of solid boundaries. These solid boundaries are normally considered as completely rigid in theoretical or numerical calculations, however, this assumption is not always valid. Some hydraulic turbines have noncompletely stiff casings, which can modify the dynamic response of the runner itself, affecting specially its natural frequencies and damping behavior. To determine the influence of noncompletely rigid nearby surfaces in the dynamic behavior of a submerged structure, an experimental test rig has been constructed. This test rig is based on a disk attached to a shaft and confined in a tank covered with two different casings with different mass and stiffness. For both covers and different disk to cover distances, natural frequencies and damping ratios of the disk have been obtained experimentally. Accelerometers installed on the disk and covers as well as pressure sensors are used for this purpose. Results obtained for all the cases are discussed in detail and compared with a simplified theoretical model.
Nonlinear Damage Localization in Structures Using Nonlinear Vibration Modulation of Ultrasonic-Guided Waves
Authors: He Qingbo , Shao Yong , Liao Zeping
Published: November 2016

This paper proposes a method for nonlinear damage localization in the beam and plate structures with nonlinear vibration modulation of ultrasonic-guided waves. In the proposed technique, the damaged metal beam and plate are designed to form a cantilever structure. A magnetic system is also involved in the model to control the dynamics of this cantilever structure. The oscillation model exhibits nonlinear vibration that is used to modulate the ultrasonic-guided waves. By utilizing a synchronous phase-locked demodulation technique, the nonlinear reflection profile from the nonlinear scatterer is extracted and employed for localizing the nonlinear damage. The proposed technique has the merits of being perceptive to nonlinear scattering sources, without requiring a damage-free signal, and with enhanced performance at a wide range of frequencies. These merits have been experimentally validated by localizing fatigue crack in a metal beam and imaging simulated contact defect in a metal plate. The proposed technique is suitable in the structural health monitoring (SHM) for nonlinear damage localization in the absence of a baseline signal by ultrasonic-guided waves.
Dynamic Model for Fatigue Evolution in a Cracked Beam Subjected to Irregular Loading
Authors: Hai Nguyen Son , Chelidze David
Published: November 2016

The coupling of vibration and fatigue crack growth in a simply supported uniform Euler–Bernoulli beam containing a single-edge crack is analyzed. The fatigue crack length is treated as a generalized coordinate in a model for the mechanical system. This coupled model accounts for the interaction between the beam oscillations and the crack propagation dynamics. Nonlinear characteristics of the beam motion are introduced as loading parameters to the fatigue model to match experimentally observed failure dynamics. The method of averaging is utilized both as an analytical and numerical tool to: (1) show that, for cyclic loading, our fatigue model reduces to the Paris' law and (2) compare the predicted fatigue damage accumulation with the experimental data for chaotic and random loadings. A utility of the fatigue model is demonstrated in estimating fatigue life under irregular loadings.
District Heating Cost Optimization
Authors: Eicoff Aaron P.
Published: November 2016

When buildings of various use-types are served by a district energy system, many societal benefits occur, including improved capacity utilization, reduced energy use, and more cost-effective redundancy. In addition, a central system may benefit financially from commodity leveraging, utility incentives and cogeneration. Energy conversion and transport efficiency for steam and hot water are explored and presented. System optimization curves, including generation and distribution, are presented along with long-term financial comparisons to decentralized systems.
Development of Rotary Engine Based Micro-DG/CHP System
Authors: Hack Richard L. , Venaas Max R. , McDonell Vince G. , Kaneko Tod M.
Published: November 2016

Small scale Distributed Generation with waste heat recovery (<50 kW power output, micro-DG/CHP) is an expanding market supporting the widespread deployment of on-site generation to much larger numbers of facilities. The benefits of increased overall thermal efficiency, reduced pollutant emissions, and grid/microgrid support provided by DG/CHP can be maximized with greater quantities of smaller systems that better match the electric and thermal on-site loads. The 3-year CEC funded program to develop a natural gas fueled automotive based rotary engine for micro-DG/CHP, capitalizing upon the unique attributes engine configuration will be presented including initial performance results and plans for the balance of the program.
Modeling and Simulation of Tethered Undersea Kites
Authors: Wang Yao , Olinger David J.
Published: November 2016

In this work an emerging hydrokinetic energy technology, Tethered UnderSea Kites (TUSK), is studied. TUSK systems use an axial-flow turbine and generator mounted on a rigid, underwater winged kite that is tethered to a floating surface buoy to extract power from an ocean current. The tethered underwater kite is controlled to travel in cross-current motions at a high velocity which is at least four to five times larger than the ocean current velocity. This higher velocity significantly increases the potential power output compared to conventional fixed marine turbines. Modeling and simulation of the kite-tether dynamics in a TUSK system is studied by developing and solving governing equations of motion derived from Euler-Lagrange equations. Models for physical effects appropriate to TUSK systems are developed, including for turbine power and turbine drag, kite wing hydrodynamic forces, and the effect of turbine blade tip cavitation on turbine power output. A baseline simulation that includes these modeled effects and a simple kite control scheme is studied to estimate cross-current kite trajectories, turbine power output, kite hydrodynamic forces, kite pitch, roll and yaw dynamics, and tether tensions. Once the baseline simulation case has been fully explored, a parametric study is conducted that varies key design and flow parameters including ocean current speed, kite weight and wing area, turbine rotor area, tether length, and kite control system parameters.
Performance of a Solar Thermal Adsorption Cooling System Based on Metal Organic Frameworks in Texas
Authors: Demirocak Dervis Emre , Kabir M. M.
Published: November 2016

In this study, the performance of the basic adsorption cooling system based on a metal organic framework, HKUST-1, is investigated and compared with that of a zeolite based system. The optimal regeneration temperature to maximize the COP of the HKUST-1-water based basic adsorption cycle is presented. The solar-thermal powered adsorption chiller model running on the HKUST-1-water based basic adsorption cycle is developed and integrated into a building model (two-story house located in Kingsville, Texas) in TRNSYS. The yearly performance of the integrated system is simulated by employing the latest typical meteorological year data (TMY3) for Kingsville, Texas. The solar fraction of the solar-assisted adsorption cooling system is also presented.
Exergy Analysis of Solar Chimney for Saudi Arabian Weather Conditions
Authors: Hussain Faisal M. , Al-Sulaiman Fahad A.
Published: November 2016

Solar thermal energy is considered one of the most promising renewable energy resources, especially for high intensive solar radiation locations, such as Saudi Arabia. Therefore, there is a need to assess the performance of one potential dominant solar thermal energy technology that can be applied in Saudi Arabia, which is Solar Chimney Power Plant (SCPP). SCPP is guided through natural draft utilizing solar radiant energy to impart ascending thrust to the flow of air and therefore, transforming the radiant energy to run the turbine. This paper presents the exergy analysis of the assumed model of the SCPP and presents its performance for Dhahran, Saudi Arabia, as an illustrative of the exergy model developed. The modeling was validated against published data. The tower height is 195 m and the collector diameter is 240 m. The tower can produce, on average, around 123kW during daytime and has, on average, air mass flow rate of around 160 kg/s. The exergetic efficiency was found to be around 0.45%.
A New Phase Change Material for High Temperature Thermal Energy Storage
Authors: Jiang Yifeng , Sun Yanping , Bruno Frank , Li Sean
Published: November 2016

The eutectic Na2CO3-NaCl molten salt was investigated as a new high temperature phase change material for solar thermal energy storage. The composition of the eutectic binary salt was determined with the aid of FactSage software and its thermophysical properties were investigated using a Simultaneous Thermal Analyzer, X-Ray Diffraction and a Scanning Electron Microscope. Eutectic Na2CO3-NaCl salt shows higher measurement values in a CO2 atmosphere than these in a N2 atmosphere in terms of heats of both fusion and solidification. Thermal stability analysis indicates that the eutectic molten salt has higher thermal stability in a CO2 environment without weight loss at temperatures below 700 °C compared with 0.51% weight loss at the melting point around 640 °C in a N2 atmosphere. The weight loss observed in the latter, is most likely to be due to the salt’s decomposition at high temperature. The thermophysical properties of the salt such as melting temperature, heats of both fusion and solidification, as well as the phase identification and phase morphology varied slightly after 100, 200 and 300 thermal cycle tests. Therefore, the eutectic Na2CO3-NaCl salt has a good thermal and phase stability. It therefore is a promising high temperature phase change material when used in a CO2 environment.
CFD Based Study on an Earth Pipe Heat Exchanger With Different Pipe Geometries
Authors: Srivastava Shashank , Sharma Aashish , Ajay Ketan
Published: November 2016

Heating and cooling is a prime need for various day to day operations and one of the most basic requirements is space conditioning. A huge amount of energy all across the globe is being used for this purpose using various conventional & non-conventional energy based resources. But environmental problems, fast depletion nature and high prices associated with the use of conventional energy sources is becoming a big problem, due to which promotion of non-conventional energy sources becomes important. The use of an in-ground heat exchanger is a unique technique for space conditioning with reduced energy consumption. A lot of research and studies have been done on the design of such systems. This paper presents a study based on the CFD modelling and simulation to analyze the effect on the effective performance of the system by varying the geometry of ducts and using the extended surface to increase the heat transfer rate. Also, a comparative study of performance of earth tube heat exchanger for different cross section of ducts is also presented.
The Potential of Sky Radiation With Change in Design Parameters
Authors: Parsons Adrienne M. , Sharp M. Keith
Published: November 2016

This study evaluated the building cooling capacity of sky radiation, which was previously identified to have the greatest cooling potential among common ambient sources for climates across the US. [Robinson, et al. 2013b]. A heat pipe augmented sky radiator system was simulated by a thermal network with nine nodes, representing a thin polyethylene cover, white (ZnO) painted radiator plate [Duffie & Beckman 2013], condenser and evaporator ends of the heat pipe, thermal storage fluid (water), tank wall, room, sky and ambient air. Heat transfer between nodes included solar flux and sky radiation to cover and plate, wind convection and radiation from cover to ambient, radiation from plate to ambient, natural convection and radiation from plate to cover, conduction from plate to condenser or, two-phase heat transfer from evaporator to condenser, natural convection from evaporator to water and from water to tank wall, natural convection and radiation from tank wall to room, and overall heat loss from room to ambient. Nodal temperatures were simultaneously solved as functions of time using Typical Meteorological Year (TMY3) weather data. Auxiliary cooling was applied as needed to limit room temperature to a maximum of 23.9°C. For this initial investigation, a moderate climate (Louisville, KY) was used to evaluate the effects of radiator orientation, thermal storage capacity and cooling load to radiator area ratio, LRR. Louisville and two challenging climates (Miami, FL and New Orleans, LA) were then used to evaluate five cover configurations — zero, one and two covers with unconstrained temperature, and zero and one cover with temperature limited to the dew point of ambient air to simulate condensation on the cover. Results were compared to a Louisville baseline with LRR = 10 W/m2K, horizontal radiator and one cover with constrained temperature, which provided an annual sky fraction (fraction of cooling load provided by sky radiation) of 0.861. A decrease to 0.857 was found for an increase in radiator slope to 20°, and a drop to 0.833 for 53° slope (latitude + 15°, a typical slope for solar heating). These drops were associated with increases in average radiator temperature by 0.2°C for 20° and 1.5°C for 53°. A 25% decrease in storage capacity caused a decrease in sky fraction to 0.854. Sky fractions were 0.727 and 0.963 for LRR of 20 and 5, respectively. Sky fractions for the baseline system in Miami and New Orleans were 0.505 and 0.603, respectively. In all three climates, performance was little affected by constraining the cover temperature and by adding a second cover. These results confirm the potential for passive cooling of buildings by radiation to the sky. Climate, LRR and thermal storage capacity had strong effects on performance, while the cover configuration did not. Radiator slope had a surprisingly small impact, considering that the view factor to the sky at 53° tilt is less than 0.5.
Effect of Flow Rate and Particle Size on Heat Transfer to Dense Granular Flows
Authors: Watkins Megan F. , Gould Richard D.
Published: November 2016

The increasing demand for renewable energy sources necessitates the development of more efficient technologies. Concentrated solar power (CSP) towers exhibit promising qualities, as temperatures greater than 1000°C are possible. The heat transfer fluid implemented to capture the sun’s energy significantly impacts the overall performance of a CSP system. Current fluids, such as molten nitrate salts and steam, have limitations; molten salts are limited by their small operational temperature range while steam requires high pressures and is unable to act as an effective storage medium. As a result, a new heat transfer fluid composed of ceramic particles is being investigated, as ceramic particles demonstrate no practical limit on operation temperature and have the ability to act as a storage medium. This study sought to further investigate the use of dense granular flows as a new heat transfer fluid. Previous work validated the use of such flows as a heat transfer fluid; the present work examined the effect of flow rate, as well as the particle size and type on the heat transfer to the particle fluid. Three different types of particles were tested, along with two different diameter particles. Of the three materials tested, the particle type did not appear to effect the heat transfer. Particle diameter, however, did effect the heat transfer, as a smaller diameter particle yielded slightly higher heat transfer to the fluid. Flow rates ranging from 30 to 200 kg/m2-s were tested. Initially, the heat transfer to the flow, characterized by the convective heat transfer coefficient, decreased with increasing flow rate. However, at approximately 80 kg/m2-s, the heat transfer coefficient began to increase with increasing flow rate. These results indicate that a dense granular flow consisting of small diameter particles and traveling at very slow or fast flow rates yields the best wall to “fluid” heat transfer.
Design and Start-Up of Two Pilot Plants for Molten Salts Storage Testing
Authors: Cabeza Luisa F. , Prieto Cristina , Miró Laia , Gasia Jaume , Peiró Gerard
Published: November 2016

The design and building of two thermal energy storage (TES) pilot plants to be used for concentrated solar power (CSP) applications is explained and compared. Both pilot plants are based on a two-tank molten salt storage technology (composed by a hot and a cold tank) which works under a TES process. This process has three main steps: charge, storage and discharge. Charging and discharging cannot be performed simultaneously, and the whole process is considered to be cyclic: (1) during the charging process, the heat transfer fluid (HTF) is heated up with the solar collectors from the solar field up to a temperature of 393 °C. Then, the HTF exchanges its energy with the molten salts at the heat exchanger. During this process, the molten salts flow from the cold tank through the heat exchanger, arriving at the hot tank at a temperature up to 388 °C. (2) During the storage, the molten salts are stored in the hot tank at a temperature up to 388 °C. (3) Finally, during the discharging process, which corresponds to the period when no more solar radiation is available, the energy stored in the hot tank is used to produce electricity. Molten salts flow from the hot tank through the heat exchanger to the cold tank, heating up the HTF. This HTF carries the thermal energy to the power block, where it is converted to electricity. The first pilot plant presented in this study was designed and built by Abengoa in 2008 in Seville (Spain). It consisted of an 8.1 MWhth facility which contained all the components (successfully tested and optimized) that were lately used in commercial CSP plants. The second pilot plant consisted of a 0.3 MWhth facility designed, built and tested in 2008 at the University of Lleida (Spain) in conjunction with Abengoa. The TES material used in both pilot plants was a mixture of sodium nitrate and potassium nitrate (60% NaNO3 and 40% KNO3). The main differences between the two facilities fall on the size and on the operating mode: while the facility in Seville is charged with solar energy and discharged against a power cycle, the facility in Lleida is charged with an electrical boiler and discharged against a HTF-air heat exchanger. This paper presents the main components of both facilities and the lessons learnt during operation at pilot plant scale, which have been found to be useful to guarantee the correct start-up and operation of new commercial CSP plants built worldwide. These lessons learnt include key aspects like filling up the storage tanks, heat tracing systems and equipment used.
Utilizing Waste Heat From Hybrid Energy Systems for Pyrolysis and Other Processes
Authors: Verner Kelley M. , Ostrom Lee T. , McKellar Michael G.
Published: November 2016

Nuclear reactor systems present a promising sustainable energy source for the future. Simply, a nuclear reactor heats a coolant that powers a turbine to create electricity. The coolant then can either be re-cooled or can be used for process heat applications. By utilizing the heat off the reactor less energy is wasted. A few of the proposed uses of the wasted heat are water desalination, hydrogen production, or pyrolysis. Nuclear power plants most often provide baseload power and are very inflexible. One way to address this is to use nuclear hybrid energy systems.

The goal of this research is to create a system that mimics the waste heat from a reactor, demonstrates how to utilize that heat, and shows that when energy demand is low the reactor does not need to reduce power; the energy can be directed elsewhere to create goods. We have developed an Energy Conversion Loop to act as a testbed for experimentation of the aforementioned processes and test the possibility of nuclear hybrid energy systems.

The current design consists of a series of heat exchangers that transfer heat between hot air 427 °C (800 °F) and room temperature water. Each loop of the system mimics a type of process that can be tested with a waste heat application. Early models show the system is capable of producing air temperatures near 427 °C (800 °F) and steam temperatures of 154.4 °C (310 °F). These temperatures match needed process heat temperatures for pyrolysis, multi-effect distillation, and multi-stage flash distillation and can be used to simulate other processes for lab scale testing of wasted process heat. Physical testing will be completed in the future to confirm these results.
Performance Characterization of Bi-Directional Turbines for Use in Thermoacoustic Generator Applications
Authors: Boessneck Eric T. , Salem Thomas E.
Published: November 2016

Bi-directional turbines convert oscillating axial fluid flow into uniform radial rotation and have proven effective in wave energy harvesting applications, like ocean wave generators. Two of the most widely studied designs for these scenarios are the Wells and axial turbines. This study characterizes the effectiveness of these turbines for use with a thermoacoustic generator; which is a relatively new technology that uses an induced temperature gradient to propagate acoustic waves within an enclosed, looped chamber. These generators are widely applied to refrigeration cycle systems; yet when paired with a bi-directional turbine, the resulting sound wave can be harnessed to generate electricity.

This paper begins with a discussion of the thermoacoustic application covering relevant issues for the turbine. Next, the Wells, axial, and a combined hybrid turbine are presented in thorough detail including governing design features that were explored. Fabrication of a test fixture and turbine prototypes and experimental results from a broad ranging study of the performance of the turbine designs is shown. Finally, conclusions from the obtained results are discussed.
Models for Prediction of Soiling-Caused Photovoltaic Power Output Degradation Based on Environmental Variables in Doha, Qatar
Authors: Guo Bing , Javed Wasim , Khan Saadat , Figgis Benjamin , Mirza Talha
Published: November 2016

In a previous study, using field measurement data from the Qatar Foundation Solar Test Facility, the daily change in Cleanness Index (CI), a measure of PV performance ratio, corrected for temperature and normalized to a clean PV module, was correlated to environmental variables including airborne particulate matter concentration (PM10), wind speed (WS), and relative humidity (RH). A linear empirical equation between daily CI change and the daily average PM10, WS, RH was developed using Microsoft Excel®. However, the model was not extensively evaluated due to the small data set available then. In this study, a larger data set was used to fit the linear model for daily CI change and daily average values of PM10, WS, and RH. In addition, a semi-physical model was developed to take into account the non-linear mechanics of turbulent deposition, resuspension of deposited dust, and the effect of relative humidity on resuspension. The regression and solver functions of Microsoft Excel® was employed to fit the data. The R-squared values of the linear model and the semiphysical model are 0.0949 and 0.1774, respectively. The semi-physical model predicts the daily ΔCI slight more accurately than the linear model. However, for prediction of cumulative ΔCI over longer periods of time, the two models perform roughly the same. Overall, both models are able to predict the two-month ΔCI with an uncertainty of less than 16%. The results from this study suggest that it is possible to use mathematical models to calculate PV power output degradation in the Doha, Qatar area. This may be a significant step towards development of models that can be used for economic analysis of PV solar projects and plant maintenance.
Effects of Irradiance and Ambient Temperature on a Decision-Making Tool for Rooftop PV Array Sizing for Commercial Buildings
Authors: Bianchi Carlo , Smith Amanda D.
Published: November 2016

Reducing global emissions and meeting the electricity generation needs of urban areas are compelling energy issues. Rooftop and small-scale photovoltaic (PV) technology is a quickly growing sector of the distributed generation market. The array size chosen for a PV installation is one of the main factors affecting its ability to meet a building’s electrical needs and reduce its operational emissions.

The rooftop area available for placement of PV can be a constraint on the optimization of PV array size. If the optimal array area for a specific building is larger than the area available on the rooftop, optimization using demand-matching methods is not necessary.

A new parameter EUI-R has been introduced to describe the building’s annual electrical demand with respect to the building rooftop area. It is a decision-making tool presented to help a system designer choose whether to employ an optimization method or not in selecting a PV system. The EUI-R depends on 2 general parameters, building electric demand and building rooftop area, that should be easily accessible for any system designer. This paper presents an extended study of EUI-R applied to 10 commercial building types in 3 different climate zones throughout the U.S. These cities are characterized by different latitudes and varying amounts of available solar radiation. The results show a linear dependency between optimal PV size obtained with a simple demand-matching algorithm, and building rooftop area, applicable to any building type. Any distributed energy technology serving a single building should be sized based on the specific conditions unique to the building, including electric demand and physical space available.
On-Sun Evaluation of the PHLUX Method for Heliostat Beam Characterization
Authors: Yellowhair Julius , Ho Clifford K.
Published: November 2016

Flux distributions from solar field collectors are typically evaluated using a beam characterization system, which consists of a digital camera with neutral density filters, flux gauge or calorimeter, and water-cooled Lambertian target panel. The pixels in camera image of the flux distribution are scaled by the flux peak value measured with the flux gauge or the total power value measured with the calorimeter. An alternative method, called PHLUX developed at Sandia National Laboratories, can serve the same purpose using a digital camera but without auxiliary instrumentation. The only additional information required besides the digital images recorded from the camera are the direct normal irradiance, an image of the sun using the same camera, and the reflectivity of the receiver or target panel surface.

The PHLUX method was evaluated using two digital cameras (Nikon D90 and D3300) at different flux levels on a target panel. The performances of the two cameras were compared to each other and to measurements from a Kendall radiometer. For consistency in comparison of the two cameras, the same focal length lenses and same number of neutral density filters were used. Other camera settings (e.g., shutter speed, f-stop, etc.) were set based on the aperture size and performance of the cameras. The Nikon D3300 has twice the number of pixels as the D90. D3300 provided higher resolution, however, due to the smaller pixel sizes the images were noisier, and the D90 with larger pixels had better response to low light levels. The noise in the D3300, if not corrected, could result in gross overestimation of the irradiance calculations. After corrections to the D3300 flux images, the PHLUX results from the two cameras showed they agreed to within 8% for a peak flux level of 1000 suns on the target, and less than 10% error in the peak flux when compared to the Kendall radiometer.
Multifunctional Energy Storage Composites: Design, Fabrication, and Experimental Characterization
Authors: Ladpli Purim , Nardari Raphael , Rewari Raunaq , Liu Hongjian , Slater Michael , Kepler Keith , Wang Yinan , Kopsaftopoulos Fotis , Chang Fu-Kuo
Published: November 2016

We propose the concept of Multifunctional-Energy-Storage Composites (MES Composites) which highlights a unique integration technique for embedding lithium-ion battery materials in structural carbon-fiber-reinforced-polymers (CFRP). Unlike standard lithium-ion pouch cells, the MES Composites maximizes material utilization by using CFRP facesheets to house the electrochemistry. Through-thickness polymer reinforcements are implemented to allow load transfer between the two facesheets, analogous to the sandwich structure construction.

In this work, the design rationale, materials and fabrication techniques, experimental evaluation, and performance of the first-generation MES Composites will be presented. MES Composite cells with a nominal capacity of approximately 4 Ah, with various reinforcements-array configurations, were fabricated and first tested through a series of electrochemical reference performance tests (RPT) under a strain-free condition. The MES Composite cells then underwent a mechanical-electrical-coupling test, where a quasi-static three-point-bending load was applied at increasing increments. Mechanical testing was interrupted after each increment to perform a sequential RPT to quantify any non-catastrophic degradation in the electrochemical performance.

The obtained results verify the feasibility of the concept showing that the electrochemical performance of the MES Composites can be maintained at the same level as the regular lithium-ion battery. The reinforcement architecture of the MES Composite constrains the relative motion of the battery electrodes and increases the bending rigidity, resulting in a higher load carrying capacity and inhibiting non-fatal injury of the cell under mechanical loads. This multifunctional material system can also be scaled up and ultimately provide considerable weight and volume saving at the system level.
Cost Optimal Strategies of High Temperature Thermal Energy Storage Systems in Combined Heat and Power Applications
Authors: Wells Parker , Nithyanandam Karthik , Wirz Richard
Published: November 2016

As variable generation electricity sources, namely wind and solar, increase market penetration, the variability in the value of electricity by time of day has increased dramatically. In response to increase in electricity demand, natural gas “peaker plants” are being added to the grid, and the need for spinning and nonspinning reserves have increased. Many natural gas, and other heat source based, power plants exist as combined heat and power (CHP), or cogeneration, plants. When built for industrial use, these plants are sized and run based on heat needs of an industrial facility, and are not optimized for the value of electricity generated. With the inclusion of new, less expensive thermal energy storage (TES) systems, the heating and electricity usage can be separated and the system can be optimized separately. The use of thermal energy storage with CHP improves system economics by improving efficiency, reducing upfront capital expenditures, and reducing system wear.

This paper examines the addition of thermal energy storage to industrial natural gas combined heat and power (CHP) plants. Here a case study is presented for a recycled paper mill near Los Angeles, CA. By implementing thermal energy storage, the mill could decouple electric and heat production. The mill could take advantage of time-of-day pricing while producing the constant heat required for paper processing. This paper focuses on plant economics in 2012 and 2015, and suggests that topping cycle industrial CHP plants could benefit from the addition of high temperature (400–550°C) energy storage. Even without accounting for the California incentives associated with implementing advanced energy storage technologies and distributed generation, the addition of energy storage to CHP plants can drastically reduce the payback period below the 25 year expected economic lifetime of a plant. Thus thermal energy storage can make more CHP plants economically viable to build.
Comparison Analysis for TES System in Solar-Aided 600 MW Coal-Fired Power Generation System and Solar-Alone Power Generation System
Authors: Wu Junjie , Hou Hongjuan , Yang Yongping
Published: November 2016

With the shortage of fossil fuels and its negative effects on the environment, solar energy as one type of renewable energy has attracted increasing attention both socially and politically. There are two approached to use solar energy for generating electricity, i.e., using solar energy to directly to make work or integrating solar energy into fossil-fueled plant. The solar-aided coal-fired power generation (SACPG) mechanism is proven an effective way to use solar energy efficiently. In this paper, SACPG system and solar-alone parabolic trough CSP plant are modelled respectively. A comparison discussion related to TES system between SACPG system and solar-alone CSP plant is presented. The aim is to find what role of TES system will play in these two different systems.

Through analysis, the role TES system plays varies in solar-alone power generation system and SACPG system. For solar-alone power generation system, the main function for TES system lies in storing surplus solar heat. Besides, there exists an optimum loop number with highest annual SEE with a specific TES hour. However, TES system for SACPG system not only stores the surplus solar heat, but also adjusts working condition. With the help of TES system, the working condition could be set as the high-pressure extraction steam could be totally replaced by solar heat. By doing so, annual solar power generation and annual SEE could be improved compared with that without TES system.