bluuebunny/crossref_metadata_2025 huggingface dataset:
STABILITY OF BLACK CARROT ANTHOCYANINS IN THE TURKISH DELIGHT (LOKUM) DURING STORAGE
Authors: ÖZEN GÖKHAN , AKBULUT MEHMET , ARTIK NEVZAT
Published: November 2009

In this research, traditional Turkish delight (lokum) was colored with black carrot juice concentrate, and the variations in anthocyanin content, during storage at different temperatures (12, 20 and 30C) for 5‐month periods, were observed by spectrophotometer and high‐performance liquid chromatography. Analysis of kinetic data suggested a first‐order reaction for the degradation of black carrot anthocyanins in Turkish delight. Degradation rates of anthocyanins of black carrot increased with increasing temperature. It was determined that the degradation rate of black carrot anthocyanins during the storage period at 12C increased faster than that of the other temperatures (20 and 30C). The k values for 12, 20 and 30C were found to be 6.91 × 10−3, 4.21 × 10−3and 9.21 × 10−3/day, respectively. Effects of pH on the thermal stability of black carrot anthocyanins were also determined. Results showed that the stability of anthocyanins decreased as the pH value increased. Increase in pH values correlated well with the decrease in anthocyanin content of the samples during storage. In all of the samples, redness (a*) decreased during the storage at all temperatures; however, lightness (L*) increased.

PRACTICAL APPLICATIONS

Most of commercial anthocyanins used as a colorant in foods are obtained from fruits or vegetables such as: red grape, elderberry, blackcurrant, blackberry, raspberry, black chokeberry, red cabbage, black carrot, purple corn, red radish and purple sweet potato.

Turkish delight (lokum), one of the most popular traditional food products in Turkey, is a famous Turkish desert known all over the world. Lokum is produced by using sugar, water, starch, citric acid, aromatic compounds, dried fruits and natural colorant. The color of foods, which is one of the initial properties noticed in foods, is one of the most important quality parameters affecting consumers. Because of consumer anxiety over the safety of synthetic food colorants, the demand for natural food colorants has increased. Particularly, there is an increasing request for natural red food colorants as alternatives to the most commonly used synthetic red colorant. Therefore, the availability and the suitability of black carrot juice concentrate as a natural colorant instead of synthetic colorants which are considered to have some negative properties for human health was investigated by this work.
RESPONSE SURFACE OPTIMIZATION OF CONDITIONS FOR THE CLARIFICATION OF GUAVA FRUIT JUICE USING COMMERCIAL ENZYME
Authors: KAUR SAWINDER , SARKAR B.C. , SHARMA H.K. , SINGH CHARANJIV
Published: November 2009

Response surface methodology was employed to optimize the incubation temperature (36.6–53.40C), incubation time (0.95–11.05 h) and enzyme concentration (0.16–0.84 mg/100 g guava pulp) on ascorbic acid retention, clarity, viscosity and color (L value) of guava juice. A central composite rotatable design was used. Significant regression models describing the changes of ascorbic acid, clarity, viscosity and color with respect to the independent variables (enzyme concentration, temperature and incubation time) were established with the coefficient of determination, R2, greater than 0.8. The results indicated that incubation temperature was the most significant (P < 0.01) variable in ascorbic acid retention, changes in clarity and color, whereas the incubation time showed the most significant (P < 0.01) effect on the viscosity of juice. The compromised optimum condition obtained by numerical integration for clarifying guava juice were: incubation temperature 45.35C, incubation time 7.23 h and enzyme concentration 0.70 mg/100 g guava pulp with ascorbic acid 77.71 mg/100 g, clarity 34.54% transmittance, viscosity 1.24 cps and color (L value) 23.33.

PRACTICAL APPLICATIONS

Consumption of natural fruit juice as an alternative to the traditional caffeine‐containing beverages such as coffee, tea or carbonated soft drinks has increased in recent years in Asian countries. Guava juice when extracted are mostly cloudy due to colloidal suspension and is needed to be clarified as clear juice is preferred. For increased juice yield, the fungal enzymes (pectinases) assist in pectin hydrolysis, causing a significant increase in juice yield. However, the effect of enzyme treatment on guava juice clarification has not been systematically studied. If the enzyme treatment also helps in juice clarification, it will be advantageous to the guava juice process industries. Therefore, the present study was aimed to optimize the hydrolysis pretreatment parameters (incubation temperature, time of treatment and enzyme concentration) for the maximal retention of ascorbic acid, clarity and color with minimal viscosity for the development of clarified guava juice for better acceptability of the product.
PRODUCTION AND CHEMICAL CHARACTERIZATION OF PEACH (PRUNUS PERSICA) KERNEL FLOUR
Authors: PELENTIR NORBERTO , BLOCK JANE MARA , MONTEIRO FRITZ ALCILENE RODRIGUES , REGINATTO VALÉRIA , AMANTE EDNA REGINA
Published: November 2009

Peach seed is an agro‐industrial residue that corresponds to approximately 10% of the fruit weight. In this work, peach kernel flour was produced by drying at 45, 55 and 65C, with and without maltodextrin. The flour was characterized for protein, ether extract, fatty acids, fibers and minerals. The presence of maltodextrin influences the drying rate. Peach kernel flour showed values for ether extract between 23.86 ± 0.03 and 27.15 ± 0.47 g/100 g. Peach kernel fatty acids show unique characteristics, very high quantities of oleic (ω‐9) and linoleic (ω‐6) acids (around 50% each), which is rare in vegetable oils. Ash values were from 4.62 ± 0.08 to 6.52 ± 0.17 g/100 g. Protein values were from 17.11 ± 0.55 to 21.33 ± 5.56 g/100 g, concentrations comparable with those of black beans, soy beans and peanuts.

PRACTICAL APPLICATIONS

Peach harvesting season is very short; it lasts only 1 or 2 months. The peach kernel flour suggested in this work corresponds to a product that is more stable, and thus more favorable for transportation and storage, allowing its use throughout the whole year. Considering a minimum kernel yield of 50%, which corresponds to approximately 5% of the whole fruit, and that world production of peaches is estimated in 12 million tons, approximately 600,000 tons of kernel or 200,500 tons of flour could be produced, and considering a minimum kernel yield of 30%, 60,750 tons of kernel peach oil could be produced. According to the process described in this work, it is possible to produce 30.84 kg of kernel flour per 100 kg of residue per ton of fresh processed peach and that can result in a functional food, pending on further works, including biological assays and development of new products.
PHYSICAL CHARACTERISTICS OF SURIMI AND BACTERIAL CELLULOSE COMPOSITE GEL
Authors: LIN SHIH‐BIN , CHEN LI‐CHEN , CHEN HUI‐HUANG
Published: November 2009

In this study, bacterial cellulose (BC) which has high water‐absorption‐ability was added to dolphin‐fish (mahi‐mahi) surimi to assess the characteristics of composites gels. Twelve days of Gluconacetobacter xylinum (BCRC12335) fermentation decreased the pH of this medium from 4.0 to 3.6, with nata growth on the surface reaching a thickness oSf about 0.7 cm. Alkali treatment altered BC structure, creating a dense and porous network. This alkali‐treated nata (AT‐nata) exhibited high water‐holding capacity. The critical water content (CWC) of rigidity for mahi‐mahi surimi was around 80% and, when surimi water content exceeded the CWC, we found a remarkable decrease in both rigidity and gel strength of the heated surimi. The addition of 5% AT‐nata improved the gel strength of the 80% water content heated surimi predominantly by enhancing its breaking force.

PRACTICAL APPLICATIONS

In traditional Chinese‐style fish balls, a certain amount of lard is typically added to give heated surimi products a smoother mouth‐feel. In consideration of healthfulness and enhanced gelation properties, plant gums and cellulose gels are now frequently used as lard replacements in surimi products. In this study, bacterial cellulose, which has high water‐absorption ability, was added to mahi‐mahi surimi to assess the characteristics of composites gels. The surimi to which alkali‐treated nata was added demonstrated characteristics of a phase‐separated network mix gel model. The addition of an appropriate level (5% or less) of nata did not diminishing surimi gel gelation properties. The application of nata as a fat replacement and additional dietary fiber source in processed surimi‐based products appears feasible. These results make nata a potentially competitive “high‐fiber‐low‐fat” healthy surimi product emulsifier.
A STUDY ON THE SYNERGY OF MODIFIED ATMOSPHERE PACKAGING AND CHITOSAN ON STRACCIATELLA SHELF LIFE
Authors: GAMMARIELLO D. , CONTE A. , ATTANASIO M. , DEL NOBILE M.A.
Published: November 2009

In this work, the addition of different amounts of chitosan during cheese making, combined with modified atmosphere packaging (MAP) was used to prolong the shelf life of stracciatella cheese. On the packaged cheese stored at 4C microbiological, pH, gas composition and sensorial changes were monitored over an 8‐day period. Results highlighted that the combination of chitosan and MAP prolonged stracciatella cheese shelf life, if compared with the control sample. In fact, the traditional stracciatella showed a short shelf life limited to more or less 3 days, whereas the combination of chitosan and MAP allowed us to obtain a significant shelf life prolongation that accounted to about 7 days.

PRACTICAL APPLICATIONS

Consumer demand for food with health‐promoting quality is increasing. The food industry has intensified its efforts to provide safe, high‐quality products by adding natural compounds to fulfill this requirement. The results presented in this work indicate that the combination of chitosan with modified atmosphere packaging can satisfy this particular need and prolong the shelf life of stracciatella cheese. Considering that the proposed strategy is simple and relatively inexpensive, it could be very beneficial and of commercial importance to the dairy industry.
Experiences with advance care planning: older people and family members’ perspective
Authors: Jeong Sarah Yeun‐Sim , Higgins Isabel , McMillan Margaret
Published: November 2009

jeong s.y.‐s., higgins i. & mcmillan m. (2011) Experiences with advance care planning: older people and family members’ perspective.International Journal of Older People Nursing6, 176–186

doi: 10.1111/j.1748‐3743.2009.00201.x

Aims and objectives. The aim of this study is to report the findings of a case study that explored the phenomenon of advance care planning and advanced care directives in residential care settings in Australia. In particular, this study focuses on the experiences of residents’ and family members’.

Background. Understanding the phenomenon of advance care planning and advanced care directives is vital to end of life decision making. There are few studies that report the experiences of older people and family members in relation to advance care planning and advanced care directives.

Methods. A case‐study research was conducted and data was collected over 7 months involving participant observation, field notes, semi‐structured interviews and document analysis.

Findings. The participants’ early experiences with advance care planning were expressed in unpleasant, hostile and negative ways. However, those emotions and concerns were transformed to more stable, amenable and positive attitudes and feelings as issues were resolved. The factors that enhanced or inhibited the transition were described.

Conclusion. Older people and families view the end of life with broader psychosocial and spiritual meanings shaped by a lifetime of experiences. Advance care planning led to a different level of appreciation of personal entity and transcendence. However, advance care planning demands concerted action and support by everyone involved.
Contact Transcleral Ciliary Body Photodynamic Therapy with Verteporfin in Pigmented Rabbits: Effect of Repeated Treatments
Authors: Charisis Spyridon K. , Naoumidi Irene I. , Ginis Harilaos S. , Detorakis Efstathios T. , Tsilimbaris Miltiadis K.
Published: November 2009

We studied the effect on the intraocular pressure (IOP) and the ciliary body (CB) morphology after four consecutive contact transcleral photodynamic treatments of the ciliary body (CB‐PDT) with verteporfin in pigmented rabbits. Twenty‐two pigmented rabbits underwent CB‐PDT (study group), performed once (six rabbits) or repeated for up to four times (16 rabbits). Six additional rabbits received only laser treatment without photosensitizer administration (control group). CB‐PDT was performed in one eye in rabbits of the study group, with the fellow eye serving as internal control. Verteporfin dosage was 1 mg kg−1as bolus injection and laser settings were 40 mW (600 μm core optical fiber) for 1.5 min per spot, for 10 spots. In repeated CB‐PDT, treatments were performed in 4‐day intervals. Daily IOP measurements were recorded. Histological studies were performed at selected time points. An IOP reduction, more sustained following repeated treatments, was detected in all treated eyes but not in fellow eyes or in the control group. On the average, the IOP was restored to pretreatment levels 4 days after the last treatment. No serious adverse events were observed and the CB architecture was intact at the end of the experiment. Repeated CB‐PDT is safe and results in a short‐term reduction of IOP. Induced CB alterations are reversible.
Cognitive Development and Learning: Analyzing the Building of Skills in Classrooms
Authors: Schwartz Marc
Published: November 2009

This article explores the unique and personal experience of learning within a broader framework of development called skill theory. The framework offers a perspective for recognizing within a diversity of experiences a stable order of increasing complexity in skills that individuals display as they execute or demonstrate changes in their understanding. This order is described in terms of a scale, or ruler, that quantifies across domains the achievement of greater levels of complexity in ability. In particular, we explore the process adults follow as they attempt to understand and apply ideas from science and leadership to allow the reader to witness how individual experiences can map onto a “universal” scale of learning and development.
Examining the “Whole Child” to Generate Usable Knowledge
Authors: Rappolt‐Schlichtmann Gabrielle , Ayoub Catherine C. , Gravel Jenna W.
Published: November 2009

Despite the promise of scientific knowledge contributing to issues facing vulnerable children, families, and communities, typical approaches to research have made applications challenging. While contemporary theories of human development offer appropriate complexity, research has mostly failed to address dynamic developmental processes. Research typically fragments or splits the human organism into “investigatable” units—biology, behavior, culture, genetics, relationships, innate modules of mind, etc.—resulting in the inevitable loss of the person as an integrated, embodied center of agency. This is problematic for generating knowledge that is usable because in educational practice the unit of analysis and application is the whole person. We discuss the problems inherent to generating usable knowledge when theory and research methodology are so deeply incongruent. In an illustrative example, we adopt a “person‐in‐context” perspective to demonstrate how research has led to the mischaracterization of maltreated children as immature, disorganized, and dysregulated. Using this “person‐in‐context” perspective in research can facilitate generating usable knowledge.
Effects of an Adaptive Game Intervention on Accessing Number Sense in Low‐Socioeconomic‐Status Kindergarten Children
Authors: Wilson Anna J. , Dehaene Stanislas , Dubois Ophélie , Fayol Michel
Published: November 2009

“The Number Race” is an adaptive game designed to improve number sense. We tested its effectiveness using a cross‐over design in 53 low socioeconomic status kindergarteners in France. Children showed improvements in tasks traditionally used to assess number sense (numerical comparison of digits and words). However, there was no improvement on non‐symbolic measures of number sense, suggesting that rather than being in number sense per se, the improvement was in number sense access; or links between symbolic and non‐symbolic representations of number. Focused adaptive interventions such as this may contribute to reducing the socioeconomic gap in math achievement.
Physician vs Patient Assessment of Dyspnea During Acute Decompensated Heart Failure
Authors: Smithline Howard A. , Caglar Selin , Blank Fidela S. J.
Published: November 2009

This study assessed agreement between physician and patient self‐reported measures of dyspnea severity during acute decompensated heart failure (ADHF). Both the physician and patient measured the change in dyspnea severity over 1 hour using 2 methods: (1) the difference of two static dyspnea measures (STATIC) and (2) a single transitional measure (TRANS). Likert scales and visual analog scales (VASs) were used. Data on 112 patients were analyzed. The mean difference between physician and patient VAS scores was 1 mm (limits of agreement: −54 to 56 mm) using the STATIC data. For TRANS data, the mean difference was 5 mm (limits of agreement: −75 to 86 mm). For the Likert scales, the weighted kappa was 0.13 and 0.23 for STATIC and TRANS data, respectively. The wide limits of agreement restrict our ability to substitute physician assessment for patient self‐assessment of dyspnea in patients with ADHF.

Congest Heart Fail. 2010;16:60–64. © 2009 Wiley Periodicals, Inc.
Juvenile recurrent parotitis: a case report
Authors: Gardner G. , Fowlie P. , Macluskey M.
Published: November 2009

Juvenile recurrent parotitis is a rare inflammatory disease characterised by intermittent sudden onset episodes of parotid swelling unrelated to eating. It is the second most common salivary gland disease in children, next to mumps. A case of this condition affecting a 2‐year‐old boy is reported and the literature reviewed.
Can early detection rates for cancer referred to an oral and maxillofacial surgery department be improved by consultant triage of referral letters?
Authors: Breeze J. , Attargekar V. , Moss C.E. , Gibbons A.J.
Published: November 2009

Aim:  To analyse the detection rate of oral cancer from referrals to our department and if our department policy of triaging referrals was appropriate.

Material and methods:  The authors reviewed all oral cancer referrals and urgent oral lesion referrals to the Department of Oral and Maxillofacial Surgery at Peterborough and Stamford National Health Service Foundation Trust Hospitals during 2006.

Results:  Sixty‐three patients were referred in 2006 for lesions that consultant triage suspected may be malignant or referred to be seen urgently. Thirty‐three patients were referred by general practitioners and all were subsequently seen within the 2‐week rule. Consultant triage of referral letters allocated a further 17 to been seen under the 2‐week rule timescale. An additional 13 urgent referrals were classified as not meeting the 2‐week rule criteria by the consultant that graded the letter but to be seen within 4 weeks.

Conclusion:  Our study shows that with consultant triaging of referral letters, a malignancy detection rate of 24% can be achieved.
On Lewis, Schaffer and the Non‐Reductive Evaluation of Counterfactuals
Authors: NORTHCOTT ROBERT
Published: November 2009

Jonathan Schaffer (2004) proposes an ingenious amendment to David Lewis's semantics for counterfactuals. This amendment explicitly invokes the notion of causal independence, thus giving up Lewis's ambitions for a reductive counterfactual account of causation. But in return, it rescues Lewis's semantics from extant counterexamples.

I present a new counterexample that defeats even Schaffer's amendment. Further, I argue that a better approach would be to follow the causal modelling literature and evaluate counterfactuals via an explicit postulated causal structure. This alternative approach easily resolves the new counterexample, as well as all the previous ones. Up to now, its perceived drawback relative to Lewis's scheme has been its non‐reductiveness. But since the same drawback applies equally to Schaffer's amended scheme, this becomes no longer a point of comparative disadvantage.
Efficacy of Synthetic Suburethral Slings in Female Urinary Stress Incontinence with Overactive Bladder
Authors: SEO Ju Tae , KIM Kyung Tae , KIM Tae Hong
Published: November 2009

Objectives: The aim of the present study was to investigate the efficacy of synthetic suburethral slings in female stress urinary incontinence (SUI) patients with overactive bladder (OAB).

Methods: From May 2002 to April 2005, a total of 295 women with SUI underwent suburethral sling procedure. Of the 295 women, only those who were followed up for at least 12 months were included in the study, yielding 236 patients. The patients were divided into three groups: pure SUI; SUI with OAB dry; and SUI with OAB wet. Telephone questionnaires by were used to evaluate the postoperative improvement of SUI and storage symptoms.

Results: There were significant differences in preoperative symptom score, quality of life (QoL) score, and preoperative voided volume among the three groups. There were no significant differences among the three groups in terms of the cure rate for the stress component (group 1, 88.6%; group 2, 86.2%; group 3, 86.7%; P = 0.943). Eighty percent of group 1 patients improved in frequency, but two patients (2.3%) complained of de novo urgency. In group 2, 81.5 and 82.7% improved in frequency and urgency, respectively, but one patient (1.7%) complained of de novo urge incontinence. In group 3, 76.9 and 84.4% improved in frequency and urge incontinence, respectively.

Conclusion: Suburethral slings are simple, safe and highly effective in treating SUI with OAB.
Seroprevalence of Hepatitis E Virus in the UK Farming Population
Authors: Meader E. , Thomas D. , Salmon R. , Sillis M.
Published: November 2009

Hepatitis E is a zoonosis that can be acquired by the consumption of contaminated food or water, or via person‐to‐person spread. However, little is known about the transmission of hepatitis E virus (HEV) in the UK. We investigated the epidemiology of indigenous hepatitis E infection using the PHLS Farm Cohort, a sentinel group with a history of close contact with a range of domestic animals. Ten of the 413 subjects tested were positive for hepatitis E IgG antibodies (2.4%). Seroprevalence peaked in those aged 51 to 60 years (relative risk 3.3, 95% CI: 1.0–10.5). Male participants (relative risk 3.6, 95% CI: 0.6–21.2) and those from farms in the Hereford area of the United Kingdom (relative risk 2.7, 95% CI: 0.8–8.4), an area of mixed livestock farming, were more likely to have serological evidence of previous HEVs exposure, although these findings were not statistically significant. Exposure to pigs, or water from a private supply, was not identified as a significant risk factor. The results of this study suggest that UK farming populations are exposed to HEV, but the predominant route of transmission remains elusive.
A Multilevel Approach to the Energy Management of an Automotive Polymer Electrolyte Membrane Fuel Cell System
Authors: Arsie Ivan , Di Domenico Alfonso , Pianese Cesare , Sorrentino Marco
Published: November 2009

This paper deals with on-board energy management of hybrid fuel cell vehicles equipped with a polymer electrolyte membrane fuel cell (FC) stack and a battery pack as main power source and hybridizing device, respectively. A multilevel architecture was conceived to separately manage on-board energy flows and mutual interaction between FC auxiliaries and powertrain components. At the highest-level, a splitting index map was designed to share the power requested by the driver among the fuel cell stack and batteries as function of traction power demand and batteries’ state of charge. At the intermediate-level are defined the set points at which to operate the fuel cell system (FCS) to achieve maximum efficiency. Then, at the low-level, specific control strategies are adopted to reach the set point as addressed by the intermediate-level. To guarantee the accuracy required for control strategy development, a mixed modeling approach was followed to simulate vehicle powertrain, FCS, electrochemistry, and water management. The simulations were carried out for a 60 kW FC powertrain running under severe transient maneuvers. The results show the potentialities of the proposed approach for energy management optimization, control, and diagnostics analyses.
Scaling a Solid Oxide Fuel Cell Gas Turbine Hybrid System to Meet a Range of Power Demand
Authors: VanOsdol John , Liese Eric , Tucker David , Gemmen Randall , James Robert
Published: November 2009

In recent years there has been significant interest in using the heat generated from the normal operation of a solid oxide fuel cell (SOFC) to supplant the normal combustion process of a gas turbine system. By doing this a gas turbine fuel cell hybrid power generation system is formed. Because the heat produced by a SOFC is utilized by the turbine to produce work, the hybrid system can have an overall system efficiency that greatly exceeds those of either the stand alone SOFC system, or the stand alone gas turbine system. One of the most critical problems that must be addressed in gas turbine fuel cell hybrid technology is temperature control. A hybrid system that is designed to operate efficiently for a given base load may not be easily extended to accommodate peek load. In this paper a simple hybrid system configuration using a standard SOFC and a single compressor-turbine pair is presented. This simple system is used to establish the effect that key configuration parameters have on system temperatures. The configuration model is then scaled over a range of fuel input and power output to show the limitations of the system. The system is modeled using the ASPEN PLUS® simulation software with special modules to calculate fuel cell performance.
An Experimental and Modeling Study of HCCI Combustion Using n-Heptane
Authors: Guo Hongsheng , Neill W. Stuart , Chippior Wally , Li Hailin , Taylor Joshua D.
Published: November 2009

Homogeneous charge compression ignition (HCCI) is an advanced low-temperature combustion technology being considered for internal combustion engines due to its potential for high fuel conversion efficiency and extremely low emissions of particulate matter and oxides of nitrogen (NOx). In its simplest form, HCCI combustion involves the auto-ignition of a homogeneous mixture of fuel, air, and diluents at low to moderate temperatures and high pressure. Previous research has indicated that fuel chemistry has a strong impact on HCCI combustion. This paper reports the preliminary results of an experimental and modeling study of HCCI combustion using n-heptane, a volatile hydrocarbon with well known fuel chemistry. A Co-operative Fuel Research (CFR) engine was modified by the addition of a port fuel injection system to produce a homogeneous fuel-air mixture in the intake manifold, which contributed to a stable and repeatable HCCI combustion process. Detailed experiments were performed to explore the effects of critical engine parameters such as intake temperature, compression ratio, air/fuel ratio, engine speed, turbocharging, and intake mixture throttling on HCCI combustion. The influence of these parameters on the phasing of the low-temperature reaction, main combustion stage, and negative temperature coefficient delay period are presented and discussed. A single-zone numerical simulation with detailed fuel chemistry was developed and validated. The simulations show good agreement with the experimental data and capture important combustion phase trends as engine parameters are varied.
A Parametric Thermodynamic Evaluation of High Performance Gas Turbine Based Power Cycles
Authors: Bhargava Rakesh K. , Bianchi Michele , Campanari Stefano , De Pascale Andrea , Negri di Montenegro Giorgio , Peretto Antonio
Published: November 2009

This paper discusses the gas turbine performance enhancement approach that has gained a lot of momentum in recent years in which modified Brayton cycles are used with humidification or water/steam injection, termed “wet cycles,” or with fuel cells, obtaining “hybrid cycles.” The investigated high performance cycles include intercooled steam-injected gas turbine cycle, recuperated water injection cycle, humidified air turbine cycle, and cascaded humidified advanced turbine cycle, Brayton cycle with high temperature fuel cells (molten carbonate fuel cells or solid oxide fuel cells), and their combinations with the modified Brayton cycles. Most of these systems, with a few exceptions, have not yet become commercially available as more development work is required. The results presented show that the cycle efficiency achievable with the aforementioned high performance systems can be comparable or better than a combined cycle system, a currently commercially available power generation system having maximum cycle efficiency. The main emphasis of this paper is to provide a detailed parametric thermodynamic cycle analysis, using uniform design parameters and assumptions, of the above mentioned cycles and discuss their comparative performance including advantages and limitations. The performance of these cycles is also compared with the already developed and commercially available gas turbines without water/steam injection features, called “dry cycles.” In addition, a brief review of the available literature of the identified high performance complex gas turbine cycles is also included in this paper.
Porcelain Enamelled Absorbers, Coated by Spectral Selective Tin Oxide
Authors: Simonis F. , Faber A. J. , Hoogendoorn C. J.
Published: November 2009

The use of porcelain enamelled absorbers in flat plate collectors features longevity thanks to the durability and thermal stability of the enamel finish. The porcelain enamel can be made spectral selective by coating with doped tin oxide or indium oxide. The application procedure involves an enamelling step followed by a pyrosol process with tin or indium compounds. The optical properties of tin oxide coated enamel yield values of 0.90–0.92 absorptance and 0.13–0.18 hemispherical emittance. The temperature dependence of the emittance is very small. The thermal stability has been proved up to 400°C in air.
Measurement of Buoyancy-Induced Flow Using a Self-Heated Thermistor Flowmeter
Authors: Fanney A. H. , Dougherty B. P.
Published: November 2009

The development and calibration of a self-heated thermistor anemometer is described. The variation in thermistor power dissipation as a function of fluid temperature and velocity is presented. The thermistor flowmeter, which evolves from this investigation, is used to measure the buoyancy-induced flow in a thermosyphon solar hot water system. Measured flow rates for a representative day are presented. A dimensionless heat transfer analysis, applied to the thermistor probe, yielded results in good agreement with classical heat transfer correlations for spheres.
Inter-Zone Convective Heat Transfer in Buildings: A Review
Authors: Barakat S. A.
Published: November 2009

Research work on inter-zone convective heat transfer in buildings is reviewed and the parameters that govern this process are discussed. A limited comparison between the heat transfer rates calculated by existing correlations and those obtained in a full-scale test facility is presented. A number of research areas where more work is needed are identified.
The Stratification Coefficient Approach for Predicting the Performance of Solar Air Heating Systems Utilizing Packed Bed Heat Storage
Authors: Hoerger C. R. B. , Phillips W. F.
Published: November 2009

The stratification coefficient approach is refined to allow its use for predicting the performance of solar air heating systems utilizing packed bed thermal energy storage. The partial differential equation governing the storage is eliminated from the analysis in the stratification coefficient approach. Elimination of this differential equation greatly simplifies the computation of system performance. Performance predictions calculated by the stratification coefficient approach are compared to those calculated by a numerical solution to the storage differential equation. The comparisons show good agreement between the two methods. Computation time is reduced by an order of magnitude through the use of the stratification coefficient approach. Extension of the stratification coefficient approach to solar water heating systems is discussed.
Comparison of Heat Transfer in Solar Collectors With Heat-Pipe Versus Flow-Through Absorbers
Authors: Hull J. R.
Published: November 2009

Analysis of heat transfer in solar collectors with heat-pipe absorbers is compared to that for collectors with flow-through absorbers for systems that produce hot water or other heated fluids. In these applications the heat-pipe absorber suffers a heat transfer penalty compared with the flow-through absorber, but in many cases the penalty can be minimized by proper design at the heat-pipe condenser and system manifold. When the solar collector is used to drive an absorption chiller, the heat-pipe absorber has better heat transfer characteristics than the flow-through absorber.
The Reverse Flat Plate Collector: A Stationary, Nonevacuated, Low-Technology, Medium-Temperature Solar Collector
Authors: Kienzlen V. , Gordon J. M. , Kreider J. F.
Published: November 2009

The design, analysis, construction and testing of a novel solar collector is reported. The Reverse Flat Plate Collector (RFPC) is intended to be a stationary, nonevacuated, low-technology, medium temperature solar collector—a promising alternative for intermediate temperature thermal needs (100° C<T<200° C) in developing countries. The RFPC achieves high temperatures by convection suppression. The optical and thermal properties of this device are discussed for two different design options. Sensitivity studies to some of the most important system parameters are also presented. At collector fluid temperatures of 100–150 K above ambient, the yearly energy delivery of the RFPC is comparable to that of evacuated collectors. A prototype of this collector was designed, built and tested at the Joint Center for Energy Management at the University of Colorado. The experimental results accurately confirm the high collector stagnation temperatures predicted from theory and indicate that convective heat losses are indeed suppressed.
An Experimental Study of a “Once-Through” Thermosiphon System
Authors: Celentano R. , Kirchner R.
Published: November 2009

An experimental study was conducted on the operation of a “once-through” thermosiphon system. This new type of natural circulation system, unlike the standard thermosiphon system, heats the collector fluid in one pass without any recirculation. An electrically heated manifold was used to simulate the useful solar gain. Power was varied with time in 22 half-hour increments to simulate the actual daily useful solar gain. The time-dependent responses of the system in terms of temperatures and mass flow rates were recorded and plotted. The response time for mass flow and temperature to approach steady state varied directly with the size of the power step. Two experiments were conducted; one which tracked mass flows and outlet temperatures for variable useful solar gains, and a second which tracked mass flows at constant outlet temperature for variable useful solar gains.
Welding Development for Thin-Walled Solar Receiver Panels
Authors: Carli G. , Kegel W. F. , Narayanan T. V.
Published: November 2009

This paper presents the results of the work done in a project to develop the basic fabrication methods for the continuous longitudinal welding of thin-walled tubes to form flat panels for a solar receiver and for attachment of support lugs to the panels. The paper describes the stress analysis and welding development that were performed to resolve critical design and fabrication uncertainties. The work was performed in sufficient detail to develop a reliable and cost-effective thin-walled absorber panel for a commercial solar central receiver plant.
Performance of the SSPS Solar Power Plants at Almeria
Authors: Wettermark Gunnar
Published: November 2009

The article summarizes the results of the operation of the two solar power plants of the SSPS project (Small Solar Power Systems) at Almeria, carried out within the framework of the International Energy Agency. The two power plants were built side by side in order to compare two thermal-electric techniques, one being a distributed collector system (DCS) with arrays of parabolic troughs and the other a central receiver system (CRS) with heliostats concentrating the sunlight onto the top of a tower. Each plant was constructed with a nominal capacity of 500 kWel and was expected to have a net yearly output on the order of 1 GWh.—Only the DCS plant was in operation sufficiently to enable an assessment of possible annual production of electricity. Through extrapolation one finds that the gross output of the built plant was maximal 0.25 GWh with an overall efficiency of 2.3 percent for a plant with 100 percent availability and no malfunctions. Internal electricity consumption correspondingly calculated amounts to 0.11 GWh resulting in only 0.14 GWh yearly net output. Using the experimental values from the CRS plant, it appears that its yearly gross output could have been similar to that of the DCS plant but at higher internal electricity consumption, particularly due to the trace heating of the heat transfer medium (sodium).—The technical reasons for the poor efficiency of the SSPS installation were largely that the solar climate was less favorable then assumed, dirt accumulated on the mirrors at a more rapid rate than foreseen, the nonsolar specific components were badly matched and yielded low efficiencies, and thermal inertia was crucial and almost overlooked in the planning stage.—A detailed loss analysis is presented in the article.
Exergy Analysis for the Evaluation of the Performance of Closed Thermal Energy Storage Systems
Authors: Rosen M. A. , Hooper F. C. , Barbaris L. N.
Published: November 2009

The use of exergy analysis, rather than energy analysis, for the evaluation of the performance of thermal energy storage systems is discussed. The energy and exergy relationships for a simple closed tank storage with heat transfers by heat exchanger are obtained. A complete storing cycle, as well as the individual charging, storing, and discharging periods, are considered. A numerical example for a simple case is given. The work reported is preliminary to the task of developing simplified conventions for the evaluation and comparison of the performance of thermal storages using exergy analysis methods. The establishment of such simplified conventions appears to be a necessary prerequisite to general acceptance of these methods by the engineering community.
Design of a Plane-Type Bidirectional Thermal Diode
Authors: Chen K.
Published: November 2009

The design of a plane-type, bidirectional thermal diode is presented. This diode is composed of two vertical plates and several fluid-filled loops with their horizontal segments soldered to the vertical plates. This invention is simple in construction and low in cost. The direction of heat transfer in the invented thermal diode can be easily reversed. These features of the present invention make it very attractive to solar energy utilization. Natural convection analysis for thermosyphon operations was adopted for heat transfer calculations of the fluid-filled loops. A one-dimensional heat transfer analysis was employed to estimate the heat transfer rate and ratio of heat transfer rates of the diode under forward and reverse bias.
Optimal Design of Solar Energy Systems With Uncertain Data
Authors: Leigh Richard W.
Published: November 2009

The technical and economic characteristics of optimized solar energy systems can be expressed in a concise mathematical expression and this expression manipulated to show the dependence of total system cost on variables such as collector cost and efficiency, weather data, or the cost of the backup fuel. The lack of certain knowledge of future weather, fuel prices, and system performance implies that a system optimized, with respect to an assumed set of these data, may not be optimal with respect to the realities of operation. This formulation demonstrates clearly how the life cycle costs of the system increase as a result of errors in estimating various system parameters; in most cases, the costs of errors are not large over their expected ranges. In particular, most solar energy systems designed to satisfy a given load (that is, having a given nameplate capacity) should be optimized for the best weather they may encounter, and this design used wherever the systems are economically viable, as it is likely that the savings due to standardization will outweigh the relatively small costs of being imperfectly optimized.
Melting of a Free Solid in a Spherical Enclosure: Effects of Subcooling
Authors: Roy Sanjay K. , Sengupta Subrata
Published: November 2009

The melting process within a spherical enclosure with the solid phase uniformly subcooled initially has been studied. The preliminary analysis of the problem is similar to a previous study where the degree of subcooling was zero. However, the heat transfer equation has been modified to include the effects of a temperature gradient in the solid core. As a result, a closed-form solution cannot be obtained. At every time step, the unsteady conduction equation has been solved numerically using a toroidal coordinate system, which has been suitably transformed to immobilize the moving boundary and to transform the infinite domain into a finite one. The temperature gradient at the surface is now used to solve the film equation numerically. The melt time, Nusselt number, and melt flux distributions have been obtained over a range of the parameters (Sb, Ste/Cp*, and 1 /Prα*) normally encountered in solar thermal systems.
The Design and Testing of a Highly Insulating Glazing System for Use With Conventional Window Systems
Authors: Arasteh Dariush , Selkowitz Stephen , Wolfe John R.
Published: November 2009

In most areas of the United States, windows are by far the poorest insulating material used in buildings. As a result, approximately 3 percent of the nation’s energy use is used to offset heat lost through windows. Under cold conditions, conventional double glazings create uncomfortable spaces and collect condensation. However, with the recent introduction of low-emissivity (low-E) coatings and low/conductivity gas filling to respectively reduce radiative and conductive/convective heat transfer between glazing layers, some manufacturers are beginning to offer windows with R-values (resistance to heat transfer) of 4 hr-ft2-F/Btu (0.70 m2-C/W). This papers presents designs for and analysis and test results of an insulated glass unit with a center-of-glass R-value of 8-10; approximately twice as good as gas-filled low-E units, and four times that of conventional double glazing. This high-R design starts with a conventional insulated-glass unit and adds two low-emissivity coatings, a thin glass middle glazing layer, and a Krypton or Krypton/Argon gas fill. The unit’s overall width is 1 in. (25 mm) or less, consistent with most manufacturers’ frame and sash design requirements. Using state-of-the-art low-emissivity coatings does not significantly degrade the solar heat gain potential or visible transmittance of the window. Work to date has substantiated this concept of a high-R window although specific components require further research and engineering development. Demonstration projects, in conjunction with utilities and several major window manufacturers, are planned. This high-R window design is the subject of a DOE patent application.
Matching Collector’s Azimuthal Orientation and Energy Demand Profile for Thermosyphonic Systems
Authors: Sokolov M. , Vaxman M.
Published: November 2009

When a load profile is given, a thermosyphonic solar water heater’s collector’s azimuthal orientation should be considered as a parameter for maximizing the system’s performance. This is demonstrated by simulating such a system with various azimuthal collectors orientation subjected to a single fixed or a daily routine load during the day. The results indicate that the system performance, which is measured here by the average (or “mixed-cup”) temperature of the withdrawn load, could be improved appreciably by a proper match between the collector’s azimuthal orientation and the specifics of the load profiles.
Numerical Simulation of the Charging of Liquid Storage Tanks: Comparison With Experiment
Authors: Lightstone M. F. , Raithby G. D. , Hollands K. G. T.
Published: November 2009

The degree of thermal stratification maintained in hot water storage tanks has a significant impact on the performance of a solar energy system. This paper presents an axisymmetric finite volume model analysis of the charging of a tank with hot water, and compares the predictions with experimental results from the literature. The results show the capabilities and deficiencies of such a modeling technique for this type of problem. The importance of inlet fluid turbulence to tank destratification is demonstrated and inclusion of a simple turbulence model is found sufficient to yield good agreement with measurement. The model predictions also provide insight into when a simple one-dimensional plug flow model will be adequate. In addition, the model is used to evaluate the effect during charging of heat conduction in the tank wall on the temperature field in the fluid. Recommendations are made regarding future work on the development of detailed numerical codes for simulating the charging of liquid storage tanks.
Numerical Model of a Rotating Prism Wall: Its Validation and Predicted Device Performance for a Variety of Situations
Authors: Faiman D. , Feuermann D. , Huleihil M.
Published: November 2009

A numerical model has been developed which describes the temperature distribution as a function of time within the storage elements of a Rotating Prism Solar Storage Wall. The model is tested against data obtained from a full-scale Rotating Prism Wall at Sede Boqer in Israel, and found to reproduce the measured temperatures extremely well. The thus validated model is used to predict the performance of such devices in various kinds of climate and to compare this performance with that to be expected from a nonvented Trombe Wall of standard design. In all cases the Rotating Prism Wall is found to provide considerably more useful energy than a nonvented Trombe Wall.
Design, Construction, and Initial Operation of a 3355 m2 Solar Pond in El Paso
Authors: Reid R. L. , Swift A. H. P. , Boegli W. J. , Kane V. R. , Castaneda B. A.
Published: November 2009

A 3355 square meter, 3.3 m deep water storage pond in El Paso, Tex. was converted to a salt-gradient solar pond to supply industrial process heat to an adjacent food processing plant. Approximately 1.9 × 106 kg of sodium chloride salt was obtained to prepare near saturated brine for pond construction. Design and construction of the solar pond are described in detail including the lining technique, salt dissolution method, diffuser design, instrumentation, maintenance of optical clarity, and gradient establishment, including resolution of initial problems in gradient stability. The solar pond has been in continuous operation for over three years.