bluuebunny/crossref_metadata_2025 huggingface dataset:
THERMOPHYSICAL PROPERTIES OF MATE LEAVES: EXPERIMENTAL DETERMINATION AND THEORETICAL EFFECT OF MOISTURE CONTENT
Authors: ZANOELO EVERTON FERNANDO , BENINCÁ CRISTINA , RIBEIRO EVALDO
Published: October 2010

An experimental investigation to determine the specific heat, thermal conductivity and apparent density of mate leaves (Ilex paraguariensis) was carried out. The experimental method of mixtures and a quasi‐adiabatic calorimeter were used to obtain a specific heat of dry leaves close to 1780 ± 450 J/kg/K. A thermal conductivity of 0.17 ± 0.01/W/m/K was tuned on transient experimental measurements of temperature in a dry bar of mate leaves. A dynamic one‐dimensional heat transfer model was involved in this procedure of tuning. An apparent density equal to 750 ± 40 kg/m was experimentally found. The effect of moisture content on these thermophysical properties was also theoretically investigated by involving simplified models based on properties of only dry matter and water. Analogous results available in the literature support the reliability of all experimental data and equations presented in this investigation.

PRACTICAL APPLICATIONS

Mate manufacturing basically involves a stage of enzymatic deactivation and a process of drying that are together responsible for almost the full energy consumed in the mate industry. A detailed description of both these processes with mathematical models is a cheap and safe way to process optimization and energy saving. However, the knowledge of the specific heat, thermal conductivity and density of the processed material whose availability is limited in the literature is required for model solution.
ENERGY AND EXERGY ANALYSES ON DRYING OF OLIVE LEAVES (OLEA EUROPAEA L.) IN TRAY DRIER
Authors: ERBAY ZAFER , ICIER FILIZ
Published: October 2010

Recently, olive leaves have a high potential for industrial exploitation in the food industry. The main process in olive leaf treatment is drying. Because drying is an energy‐intensive process, analyzing and improving the drying systems is important. In this study, olive leaves were dried in a tray drier and the performance of the drying process was evaluated using energy and exergy analyses methods. The effects of the drying air temperature and the velocity on the performance of the drying process were discussed. While the energy utilization ratio values varied between 14.05% and 26.21%, the exergetic efficiencies varied between 55.95% and 75.12%. It was inferred that exergetic efficiencies increased as the drying air temperature decreased and the drying air velocity increased. They were influenced mainly by the drying air temperature.

PRACTICAL APPLICATIONS

Although olive trees cover ∼8 million ha in the whole world and scientific studies show the importance of olive leaves, there are few examples of using olive leaves industrially. The main process in olive leaf treatment is drying, and there has been no information on the thermodynamic analysis of the drying of olive leaves in the open literature according to the authors' knowledge. Thermodynamic analysis is an important step for designing and optimizing the olive leaf treatment. It is believed that such a study would contribute the industrial exploitation of olive leaves.
OPTIMIZATION AND SENSITIVITY ANALYSIS OF AN EXTENDED DISTRIBUTED DYNAMIC MODEL OF SUPERCRITICAL CARBON DIOXIDE EXTRACTION OF NIMBIN FROM NEEM SEEDS
Authors: ZAHEDI G. , ELKAMEL A. , BIGLARI M.
Published: October 2010

In this article, supercritical extraction of nimbin from neem seeds has been studied. In order to investigate the effect of parameters on nimbin extraction yield, a partial differential equation model based on mass conservation principles. The model was solved using MATLAB software. The results were successfully validated with available laboratory experimental data. The optimum values of the operating parameters were obtained using gradient search strategy. Optimization routine was employed to maximize process profit. The optimum value of temperature, pressure, CO2 flow rate and particle diameter were found to be 305K, 177.339 bar, 0.9660 cm3/min and 0.0575 cm, respectively. Finally, a sensitivity analysis was carried out on the different model parameters, and found that process profit is mostly sensitive to neem price.

PRACTICAL APPLICATIONS

This work uses mathematical optimization as a computational engine to arrive at the best solution for neem extraction in a systematic and efficient way. In the context of neem supercritical fluid extraction (SFE) systems, coupling optimization with suitable simulation modules opens a new avenue of possibilities. It saves money and provides economical benefits. In neem SFE process, measuring parameters and understanding the process are difficult. In this case, modeling can provide virtual environmental for operator practice.
In Silico Exploration for Identifying Structure–Activity Relationship of MEK Inhibition and Oral Bioavailability for Isothiazole Derivatives
Authors: Melagraki Georgia , Afantitis Antreas , Sarimveis Haralambos , Igglessi‐Markopoulou Olga , Koutentis Panayiotis A. , Kollias George
Published: October 2010

In this study, quantitative structure–activity/property models are developed for modeling and predicting both MEK inhibitory activity and oral bioavailability of novel isothiazole‐4‐carboxamidines. The models developed are thoroughly discussed to identify the key components that influence the inhibitory activity and oral bioavailability of the selected compounds. These selected descriptors serve as a first guideline for the design of novel and potent MEK inhibitors with desired ADME properties.
Predictive QSPR Study of the Dissociation Constants of Diverse Pharmaceutical Compounds
Authors: Mercader Andrew G. , Goodarzi Mohammad , Duchowicz Pablo R. , Fernández Francisco M. , Castro Eduardo A.
Published: October 2010

The objective of the article was to perform a predictive analysis, based on quantitative structure–property relationships, of the dissociation constants (pKa) of different medicinal compounds (e.g., salicylic acid, salbutamol, lidocaine). Given the importance of this property in medicinal chemistry, it is of interest to develop theoretical methods for its prediction. The descriptors selection from a pool containing more than a thousand geometrical, topological, quantum‐mechanical, and electronic types of descriptors was performed using the enhanced replacement method. Genetic algorithm and the replacement method (RM) techniques were used as reference points. A new methodology for the selection of the optimal number of descriptors to include in a model was presented and successfully used, showing that the best model should contain four descriptors. The best quantitative structure–property relationships linear model constructed using 62 molecular structures not previously used in this type of quantitative structure–property study showed good predictive attributes. The root mean squared error of the 26 molecules test set was 0.5600. The analysis of the quantitative structure–property relationships model suggests that the dissociation constants depend significantly on the number of acceptor atoms for H‐bonds and on the number of carboxylic acids present in the molecules.
Oleic Acid Ameliorates Amyloidosis in Cellular and Mouse Models of Alzheimer's Disease
Authors: Amtul Zareen , Westaway David , Cechetto David F. , Rozmahel Richard F.
Published: October 2010

Several lines of evidence support protective as well as deleterious effects of oleic acid (OA) on Alzheimer's disease (AD) and other neurological disorders; however, the bases of these effects are unclear. Our investigation demonstrates that amyloid precursor protein (APP) 695 transfected Cos‐7 cells supplemented with OA have reduced secreted amyloid‐beta (Aβ) levels. An early‐onset AD transgenic mouse model expressing the double‐mutant form of human APP, Swedish (K670N/M671L) and Indiana (V717F), corroborated our in vitro findings when they were fed a high‐protein, low‐fat (18% reduction), cholesterol‐free diet enriched with OA. These mice exhibited an increase in Aβ40/Aβ42 ratio, reduced levels of beta‐site APP cleaving enzyme (BACE) and reduced presenilin levels along with reduced amyloid plaques in the brain. The decrease in BACE levels was accompanied by increased levels of a non‐amyloidogenic soluble form of APP (sAPPα). Furthermore, the low‐fat/+OA diet resulted in an augmentation of insulin‐degrading enzyme and insulin‐like growth factor‐II. These results suggest that OA supplementation and cholesterol intake restriction in a mouse model of AD reduce AD‐type neuropathology.
Multiple‐Element Matching Reservoir Formation and Quantitative Prediction of Favorable Areas in Superimposed Basins
Authors: Huaijie WANG , Xiongqi PANG , Zhaoming WANG , Qiuhua YU , Zhipeng HUO , Qingyang MENG
Published: October 2010

Superimposed basins in West China have experienced multi‐stage tectonic events and multicycle hydrocarbon reservoir formation, and complex hydrocarbon reservoirs have been discovered widely in basins of this kind. Most of the complex hydrocarbon reservoirs are characterized by relocation, scale re‐construction, component variation and phase state transformation, and their distributions are very difficult to predict. Research shows that regional caprock (C), high‐quality sedimentary facies (Deposits, D), paleohighs (Mountain, M) and source rock (S) are four geologic elements contributing to complex hydrocarbon reservoir formation and distribution of western superimposed basins. Longitudinal sequential combinations of the four elements control the strata of hydrocarbon reservoir formation, and planar superimpositions and combinations control the range of hydrocarbon reservoir and their simultaneous joint effects in geohistory determine the time of hydrocarbon reservoir formation. Multiple‐element matching reservoir formation presents a basic mode of reservoir formation in superimposed basins, and we recommend it is expressed as T‐CDMS. Based on the multiple‐element matching reservoir formation mode, a comprehensive reservoir formation index (Tcdms) is developed in this paper to characterize reservoir formation conditions, and a method is presented to predict reservoir formation range and probability of occurrence in superimposed basins. Through application of new theory, methods and technology, the favorable reservoir formation range and probability of occurrence in the Ordovician target zone in Tarim Basin in four different reservoir formation periods are predicted. Results show that central Tarim, Yinmaili and Lunnan are the three most favorable regions where Ordovician oil and gas fields may have formed. The coincidence of prediction results with currently discovered hydrocarbon reservoirs reaches 97%. This reflects the effectiveness and reliability of the new theory, methods and technology.
Late‐Stage Reservoir Formation Effect and Its Dynamic Mechanisms in Complex Superimposed Basins
Authors: Dejiang KANG , Xiongqi PANG , Jun KUANG , Xiaorong LUO , Hong PANG , Lei LEI
Published: October 2010

Complex superimposed basins exhibit multi‐stage tectonic events and multi‐stage reservoir formation; hydrocarbon reservoirs formed in the early stage have generally late‐stage genesis characteristics after undergoing adjustment, reconstruction and destruction of later‐stage multiple tectonic events. In this paper, this phenomenon is called the late‐stage reservoir formation effect. The late‐stage reservoir formation effect is a basic feature of oil and gas‐forming reservoirs in complex superimposed basins, revealing not only multi‐stage character, relevance and complexity of oil and gas‐forming reservoirs in superimposed basins but also the importance of late‐stage reservoir formation. Late‐stage reservoir formation is not a basic feature of oil and gas forming reservoir in superimposed basins. Multi‐stage reservoir formation only characterizes one aspect of oil and gas‐forming reservoir in superimposed basins and does not represent fully the complexity of oil and gas‐forming reservoir in superimposed basins. We suggest using “late‐stage reservoir formation effect” to replace the “late‐stage reservoir formation” concept to guide the exploration of complex reservoirs in superimposed basins. Under current geologic conditions, the late‐stage reservoir formation effect is represented mainly by four basic forms: phase transformation, scale reconstruction, component variation and trap adjustment. The late‐stage reservoir formation effect is produced by two kinds of geologic processes: first, the oil and gas retention function of various geologic thresholds (hydrocarbon expulsion threshold, hydrocarbon migration threshold, and hydrocarbon accumulating threshold) causes the actual time of oil and gas reservoir formation to be later than the time of generation of large amounts of hydrocarbon in a conventional sense, producing the late‐stage reservoir formation effect; second, multiple types of tectonic events (continuously strong reconstruction, early‐stage strong reconstruction, middle‐stage strong reconstruction, late‐stage strong reconstruction and long‐term stable sedimentation) after oil and gas reservoir formation lead to adjustment, reconstruction and destruction of reservoirs formed earlier, and form new secondary hydrocarbon reservoirs due to the late‐stage reservoir formation effect.
Differences of Hydrocarbon Enrichment between the Upper and the Lower Structural Layers in the Tazhong Paleouplift
Authors: Zhenxue JIANG , Haijun YANG , Zhuo LI , Xiongqi PANG , Jianfa HAN , Dongxu LI , Yuyan HUANG
Published: October 2010

The Tazhong paleouplift is divided into the upper and the lower structural layers, bounded by the unconformity surface at the top of the Ordovician carbonate rock. The reservoirs in the two layers from different parts vary in number, type and reserves, but the mechanism was rarely researched before. Therefore, an explanation of the mechanism will promote petroleum exploration in Tazhong paleouplift. After studying the evolution and reservoir distribution of the Tazhong paleouplift, it is concluded that the evolution in late Caledonian, late Hercynian and Himalayan periods resulted in the upper and the lower structural layers. It is also defined that in the upper structural layer, structural and stratigraphic overlap reservoirs are developed at the top and the upper part of the paleouplift, which are dominated by oil reservoirs, while for the lower structural layer, lithological reservoirs are developed in the lower part of the paleouplift, which are dominated by gas reservoirs, and more reserves are discovered in the lower structural layer than the upper. Through a comparative analysis of accumulation conditions of the upper and the lower structural layers, the mechanism of enrichment differences is clearly explained. The reservoir and seal conditions of the lower structural layer are better than those of the upper layer, which is the reason why more reservoirs have been found in the former. The differences in the carrier system types, trap types and charging periods between the upper and the lower structural layers lead to differences in the reservoir types and distribution. An accumulation model is established for the Tazhong paleouplift. For the upper structural layer, the structural reservoirs and the stratigraphic overlap reservoirs are formed at the upper part of the paleouplift, while for the lower structural layer, the weathering crust reservoirs are formed at the top, the reef‐flat reservoirs are formed on the lateral margin, the karst and inside reservoirs are formed in the lower part of the paleouplift.
Logging Evaluation of the Ordovician Carbonate Reservoir Beds in the Lungudong Region, Tarim Basin
Authors: Wenjing YANG , Chengwen XIAO , Luofu LIU , Guangzhong QI , Zhenxue JIANG , Yunchun YUAN , Weili WANG , Song YANG
Published: October 2010

In recent years, great progress has been made constantly in oil and gas exploration in the Lungudong region of the Tarim Basin. However, progress has been slow in the evaluation of its main oil‐producing horizons — the Ordovician carbonate reservoir beds. Based on previous researches and on the various data such as drilling, geology and oil test, in combination with the interpretation of each single‐well imaging and conventional logging data, and through analysis and comparison, the identification methods in imaging and conventional logging for four types of carbonate reservoir beds in this region are summarized in this paper. Calculation formulas for four reservoir bed parameters, i. e. shale content, porosity, permeability and oil saturation in this region are proposed; and reservoir beds in this region are divided into three levels (I, II and III) by combining oil test data and logging data, The lower limits of the effective porosity of reservoir beds and the fracture porosity of effective reservoir beds are determined as 1.8% and 0.04%, respectively. The physical property parameters are calculated by conventional logging curves, and the most advantageous areas for reservoir development are predicted comprehensively. On the plane, the high‐value zones of reservoir bed parameters are mainly concentrated in the N‐S‐trending strike‐slip fault, the Sangtamu fault horst zone and near the LG38 well area; vertically, the reservoir bed parameters of the Yijianfang Formation are better than those of the Yingshan and Lianglitage formations.
Hydrocarbon Accumulation Conditions of Ordovician Carbonate in Tarim Basin
Authors: Qiming LI , Guanghui WU , Xiongqi PANG , Wenqin PAN , Chunshu LUO , Chenglin WANG , Xinsheng LI , Bo ZHOU
Published: October 2010

Based on comprehensive analysis of reservoir‐forming conditions, the diversity of reservoir and the difference of multistage hydrocarbon charge are the key factors for the carbonate hydrocarbon accumulation of the Ordovician in the Tarim Basin. Undergone four major deposition‐tectonic cycles, the Ordovician carbonate formed a stable structural framework with huge uplifts, in which are developed reservoirs of the reef‐bank type and unconformity type, and resulted in multistage hydrocarbon charge and accumulation during the Caledonian, Late Hercynian and Late Himalayan. With low matrix porosity and permeability of the Ordovician carbonate, the secondary solution pores and caverns serve as the main reservoir space. The polyphase tectonic movements formed unconformity reservoirs widely distributed around the paleo‐uplifts; and the reef‐bank reservoir is controlled by two kinds of sedimentary facies belts, namely the steep slope and gentle slope. The unconventional carbonate pool is characterized by extensive distribution, no obvious edge water or bottom water, complicated oil/gas/water relations and severe heterogeneity controlled by reservoirs. The low porosity and low permeability reservoir together with multi‐period hydrocarbon accumulation resulted in the difference and complex of the distribution and production of oil/gas/water. The distribution of hydrocarbon is controlled by the temporal‐spatial relation between revolution of source rocks and paleo‐uplifts. The heterogenetic carbonate reservoir and late‐stage gas charge are the main factors making the oil/ gas phase complicated. The slope areas of the paleo‐uplifts formed in the Paleozoic are the main carbonate exploration directions based on comprehensive evaluation. The Ordovician of the northern slope of the Tazhong uplift, Lunnan and its periphery areas are practical exploration fields. The Yengimahalla‐Hanikatam and Markit slopes are the important replacement targets for carbonate exploration. Gucheng, Tadong, the deep layers of Cambrian dolomite in the Lunnan and Tazhong‐Bachu areas are favorable directions for research and risk exploration.
Different Hydrocarbon Accumulation Histories in the Kelasu‐Yiqikelike Structural Belt of the Kuqa Foreland Basin
Authors: Zhaoming WANG , Huashan LONG
Published: October 2010

The Kuqa foreland basin is an important petroliferous basin where gas predominates. The Kela‐2 large natural gas reservoir and the Yinan‐2, Dabei‐1, Tuzi and Dina‐11 gas reservoirs have been discovered in the basin up to the present. Natural gases in the Kelasu district and the Yinan district are generated from different source rocks indicated by methane and ethane carbon isotopes. The former is derived from both Jurassic and Triassic source rocks, while the latter is mainly from the Jurassic. Based on its multistage evolution and superposition and the intense tectonic transformation in the basin, the hydrocarbon charging history can be divided into the early and middle Himalayan hydrocarbon accumulation and the late Himalayan redistribution and re‐enrichment. The heavier carbon isotope composition and the high natural gas ratio of C1/C1–4 indicate that the accumulated natural gas in the early Himalayan stage is destroyed and the present trapped natural gas was charged mainly in the middle and late Himalayan stages. Comparison and contrast of the oils produced in the Kelasu and Yinan regions indicate the hydrocarbon charging histories in the above two regions are complex and should be characterized by multistage hydrocarbon migration and accumulation.
Control of Fades and Potential on Jurassic Hydrocarbon Accumulation and Prediction of Favorable Targets in the Hinterland Region of the Junggar Basin
Authors: Dongxia CHEN , Xiongqi ANG , Jun KUANG , Dejiang KANG , Lei LEI , Yougen DENG
Published: October 2010

Exploration practices show that the Jurassic System in the hinterland region of the Junggar Basin has a low degree of exploration but huge potential, however the oil/gas accumulation rule is very complicated, and it is difficult to predict hydrocarbon‐bearing properties. The research indicates that the oil and gas is controlled by structure fades belt and sedimentary system distribution macroscopically, and hydrocarbon‐bearing properties of sand bodies are controlled by lithofacies and petrophysical facies microscopically. Controlled by ancient and current tectonic frameworks, most of the discovered oil and gas are distributed in the delta front sedimentary system of a palaeo‐tectonic belt and an ancient slope belt. Subaqueous branch channels and estuary dams mainly with medium and fine sandstone are the main reservoirs and oil production layers, and sand bodies of high porosity and high permeability have good hydrocarbon‐bearing properties; the facies controlling effect shows a reservoir controlling geologic model of relatively high porosity and permeability. The hydrocarbon distribution is also controlled by relatively low potential energy at the high points of local structure macroscopically, while most of the successful wells are distributed at the high points of local structure, and the hydrocarbon‐bearing property is good at the place of relatively low potential energy; the hydrocarbon distribution is in close connection with faults, and the reservoirs near the fault in the region of relatively low pressure have good oil and gas shows; the distribution of lithologic reservoirs at the depression slope is controlled by the distribution of sand bodies at positions of relatively high porosity and permeability. The formation of the reservoir of the Jurassic in the Junggar Basin shows characteristics of favorable facies and low‐potential coupling control, and among the currently discovered reservoirs and industrial hydrocarbon production wells, more than 90% are developed within the scope of facies‐potential index FPI>0.5, while the FPI and oil saturation of the discovered reservoir and unascertained traps have relatively good linear correlation. By establishing the relation model between hydrocarbon‐bearing properties of traps and FPI, totally 43 favorable targets are predicted in four main target series of strata and mainly distributed in the Badaowan Formation and the Sangonghe Formation, and the most favorable targets include the north and east of the Shinan Sag, the middle and south of the Mobei Uplift, Cai‐35 well area of the Cainan Oilfield, and North‐74 well area of the Zhangbei fault‐fold zone.
Involvement of YC-1 in extracellular signal-regulated kinase action in rat cremasteric muscle
Authors: Hsieh Yu-Hsuan , Huang Shiang-Suo , Day Yuan-Ji , Wei Fu-Chan , Hung Li-Man
Published: October 2010

Objectives

The nitric oxide (NO)–soluble guanylate cyclase (sGC) signalling pathway is attributed to the prevention of ischaemia–reperfusion (I/R)-induced leucocyte–endothelium adhesive interactions. YC-1 (3-(5′-hydroxymethyl-2′-furyl)-1-benzylindazole), a NO-independent sGC activator, has been shown to exert cardiovascular benefits, but its action on leucocyte–endothelium interactions remains unknown. In this study, the direct effect and the underlying mechanism of the anti-adhesive action of YC-1 have been examined in cremasteric microcirculation.

Methods

Rat cremaster muscle was subjected to 4 h pudic-epigastric artery ischaemia followed by 2 h reperfusion and intravital microscopy was used to observe leucocyte–endothelium interaction and to quantify functional capillaries in rat cremaster muscle flaps.

Key findings

The values for leucocyte rolling, adhering and transmigrating were 5.5-, 6.9- and 8.8-fold greater, respectively, in I/R than in sham-control animals. YC-1 treatment rescued functional capillary density and reduced leucocyte rolling, adhering and transmigrating in I/R injured cremaster muscles to levels observed in sham-controls. Interestingly, these effects were completely blocked by the MEK (extracellular signal-regulated kinase (ERK) kinase) inhibitor (PD98059) but not by sGC or protein kinase C inhibitors. Cotreatment of PD98059 with YC-1 caused a 3.3-, 7.5- and 8.3-fold increase in the values for leucocyte rolling, adhering and transmigrating, respectively, in postcapillary venules of I/R-injured cremaster muscle.

Conclusions

This study has indicated that the anti-adhesive and functional capillary density rescue properties of YC-1 were mediated predominantly by the activation of ERK but not sGC, although YC-1 was identified to be a sGC activator. A better understanding of the action of YC-1 on the microvasculature may help shed light on its therapeutic potential for cardiovascular disease.
The sense of self‐motion, orientation and balance explored by vestibular stimulation
Authors: St George Rebecca J. , Fitzpatrick Richard C.
Published: October 2010

The sense of orientation during locomotion is derived from our spatial relationship with the external environment, sensed predominantly by sight and sound, and from internal signals of motion, generated by the vestibular sense and the pattern of efferent and afferent signals to the muscles and joints. The sensory channels operate in different reference frames and have different time‐dependent adaptive properties and yet the inputs are combined by the central nervous system to create an internal representation of self‐motion. In normal circumstances vestibular, visual and proprioceptive cues provide congruent information on locomotor trajectory; however, in cases of sensory discord there must be a recalibration of sensory signals to provide a unitary representation. We develop a means of studying these fusion processes by perturbing each channel in isolation about a consistent behavioural axis. This review focuses on creating the vestibular perturbation of the orientation sense by transmastoidal galvanic stimulation, a technique generally used to evoke balance reflexes. Vector summation across the population of semicircular canal afferents creates a net signal that is interpreted by the brain as a vector of angular acceleration in a craniocentric reference frame. The signal feeds perceptual processes of orientation after transformation that resolves the 3‐D signal onto the terrestrial or behavioural plane. Changing head posture changes the interpretation of the galvanic vestibular signal for balance and orientation responses. With appropriate head alignments during locomotion, the galvanic stimulus can be used to either steer trajectory over the terrestrial plane or perturb balance.
Formability of Al 5xxx Sheet Metals Using Pulsed Current for Various Heat Treatments
Authors: Salandro Wesley A. , Jones Joshua J. , McNeal Timothy A. , Roth John T. , Hong Sung-Tae , Smith Mark T.
Published: October 2010

Previous studies have shown that the presence of a pulsed electrical current, applied during the deformation process of an aluminum specimen, can significantly improve the formability of the aluminum without heating the metal above its maximum operating temperature range. The research herein extends these findings by examining the effect of electrical pulsing on 5052 and 5083 aluminum alloys. Two different parameter sets were used while pulsing three different heat-treatments (as-is, 398°C, and 510°C) for each of the two aluminum alloys. For this research, the electrical pulsing is applied to the aluminum while the specimens are deformed without halting the deformation process (a manufacturing technique known as electrically assisted manufacturing). The analysis focuses on establishing the effect of the electrical pulsing has on the aluminum alloy’s various heat-treatments by examining the displacement of the material throughout the testing region of dogbone-shaped specimens. The results from this research show that pulsing significantly increases the maximum achievable elongation of the aluminum (when compared with baseline tests conducted without electrical pulsing). Another beneficial effect produced by electrical pulsing is that the engineering flow stress within the material is considerably reduced. The electrical pulses also cause the aluminum to deform nonuniformly, such that the material exhibits a diffuse neck where the minimum deformation occurs near the ends of the specimen (near the clamps) and the maximum deformation occurs near the center of the specimen (where fracture ultimately occurs). This diffuse necking effect is similar to what can be experienced during superplastic deformation. However, when comparing the presence of a diffuse neck in this research, electrical pulsing does not create as significant of a diffuse neck as superplastic deformation. Electrical pulsing has the potential to be more efficient than the traditional methods of incremental forming since the deformation process is never interrupted. Overall, with the greater elongation and lower stress, the aluminum can be deformed quicker, easier, and to a greater extent than is currently possible.
Development of a Mechanistic Model for Friction Stir Channeling
Authors: Balasubramanian N. , Mishra R. S. , Krishnamurthy K.
Published: October 2010

A mechanistic model for the process specific energy as a function of the processing parameters during friction stir channeling (FSC) in Al6061-T6 was developed and investigated. The thermal cycle acting on the surface of the workpiece was measured using an infra red (IR) camera and the peak temperatures were studied as a function of the specific energy. The channel area is plotted against the process specific energy and is analyzed. A relationship between the processing conditions (tool rotational rate, traverse speed, and plunge depth) and the channel area is defined.
Assembly Molding of Tight Mechatronic System - A Model Approach
Authors: Heinle Christoph , Vetter Martina , Ehrenstein Gottfried W. , Drummer Dietmar
Published: October 2010

Offering a large variety of options, assembly injection molding represents an innovative and highly integrative technique of manufacturing mechatronic systems. This is due to the fact that it combines many technical functions such as casings and sealing of several elements made of different materials in one single manufacturing process. Particularly, the combination of various materials is a significant technological benefit and a big challenge at the same time. System tightness is a major target. This paper presents a model to improve the understanding of how leaking occurs and of the mechanisms underlying such as shrinkage and warpage behaviors related to material, process, and design. It shall also be the basis for investigations on the phenomena and development of strategies to improve the systems produced by assembly molding in terms of media tightness. Very important are the complex interaction and intereffects acting on thermal and structural shrinkages, the elements’ warpage entailed, and the adhesion between them.
The Characteristics of NO Reduction in the Reactor With Dielectric Barrier Discharge
Authors: Sun Bao-Ming , Yin Shui-E
Published: October 2010

The conventional techniques, which are being used to clean the flue gases such as catalytic reduction method for NO removal, wet and dry scrubbers for SO2 removal and ESP for particulate removal, are becoming more expensive and less suitable for small plants and mobile emission sources. Non-thermal plasma (NTP) techniques utilizing electrical discharges give an innovative approach for economical solution of gas cleaning. The studies present recent work on applying the electrical discharge plasma technology for treating gaseous pollutants, in general, and nitric oxide, in particular, as this is one of the major contributors to air pollution. The present works focuses attention on dielectric barrier discharge technique for nitric oxide removal from simulated gas compositions and investigate the effect of various operating parameters on the NO removal efficiencies at room temperature. The effects of various parameters, viz. discharge power, gas velocity, initial NO concentration (ppm), gas mixture composition, etc., on NO removal efficiency are discussed. Studies are divided into two parts: in the nitrogen atmosphere and argon atmosphere respectively, in order to investigate the effect of various operating parameters on the NO removal efficiencies at room temperature. The results in nitrogen atmosphere indicate that the influence of the discharge power, oxygen content and different initial concentration on NO removal efficiency are also studied. Conclusion that increasing discharge power is in favor of the NO removal. Adding oxygen reduce the NO removal efficiency significantly, and changing the NO initial concentration effected on NO removal efficiency but nor as good as the factors of discharge power, oxygen content. In the argon atmosphere, the dielectric barrier discharge require lower voltage level. The effect of the discharge power, gas velocity and oxygen content on NO removal efficiencies are studied and some conclusions be obtained, increasing discharge power and lowing flue gas velocity would conducive to removal, adding oxygen would hinder the removal of NO. Further result and comparative study of various cases be presented in this paper.
Development Prospects of Non-Thermal Plasma Technology Used in the Thermal Power Plants in China
Authors: Sun Bao-Ming , Yin Shui-e , Gao Xu-Dong
Published: October 2010

This paper mainly seeks to explore and answer some questions for desulfurization and denitration in thermal power plants in China. Firstly, the desulfurization and denitration technology applicated in the power plant in China at present were analyzed. It is considered that taken combination of the existed technique for purified the pollutants from the thermal power plants, not only lead to the wastage of huge amount of investment, increasing of operating costs, decreasing of the economic benefits, but also add an additional area. It is necessary to develop the integration technology of desulfurization and denitration simultaneously. Secondly the integration technology of desulfurization and denitration at present in China was briefly reviewed such as activated carbon adsorption, SNRB, etc. and most of those at a research stage include the plasma technology. In the third of the paper, the non-thermal plasma technology i.e electron-beam technique, corona discharge and dielectric barrier discharge were discussed. Finally, combined with the actual situation in China, the application prospects of the desulfurization and denitration technology using plasma discharge in the flue gas was bring up. The article also pointed out the barriers need to be overcome if the technology will be applied in power plant, as well as the development direction of desulfurization and denitration technology from flue gas in power plant in China.
Part-Load Performance Analysis of Pressurized Molten Carbonate Fuel Cell/Micro-Gas Turbine Hybrid System Using a Commercially Available Micro-Gas Turbine
Authors: Liu Ai-guo , Weng Yi-wu
Published: October 2010

This paper presented the work on the design and part-load operation of a power generation system composed of a pressurized molten carbonate fuel cell and a micro-gas turbine (MCFC/MGT). The gas turbine was based on the commercially available one and the MCFC was assumed to be newly designed for the hybrid system. The effect of different control strategies on the performance of system during part-load operation has been analyzed. Performance of system and gas turbine was compared at the same part-load considering the different control strategies. The results show that the system efficiency is lower compared with the same systems analyzed by the other authors. The system has good performance when both the turbine inlet temperature and cell temperature are maintained close to the design-point condition, but it is difficult for gas turbine to obtain the original power.
Low-Cost Material for Sensible Heat Based Thermal Storage to be Used in Thermodynamic Solar Power Plants
Authors: Py Xavier , Calvet Nicolas , Olives Re´gis , Echegut Patrick , Bessada Catherine
Published: October 2010

Thermal storage is a key component for thermal solar power plants. Today, no technology and material meet all the desired technical, economical and environmental targets. Especially in the case of extended storage (some hours), thousands of tonnes of materials are concerned leading to high investment cost as well as high energy and CO2 contents. In the present paper, an industrial ceramic made by vitrification of asbestos containing wastes is studied as a candidate to sensible heat storage material for both medium and high temperature solar power plants. The obtained stone-like material presents no hazard, no environmental impact, good thermophysical properties and a very low commercial cost (8 euros/t). Thanks to the vitrification process of the wastes, the obtained ceramic is very stable up to 1000°C and can be manufactured in a desired shape. Then, heat exchangers made of the storage material can be potentially realised and integrated in thermal processes.
An Exergy-Based Framework for Assessing Sustainability of IT Systems
Authors: Shah Amip J. , Meckler Milton
Published: October 2010

This paper proposes an exergy-based approach to evaluating the sustainability of different information technology (IT) systems. In reviewing existing standards around IT sustainability, we find that most of these metrics are based on energy efficiencies. Thermodynamically, these metrics imply sufficiency of a first-law analysis. In this paper, we show that such metrics based on the first-law of thermodynamics are necessary but not sufficient for evaluating the sustainability of IT systems. We discuss how — within the context of sustainability theory — exclusively relying on first-law metrics implicitly assumes a narrow set of system boundary conditions, and we show using an exergy-based life-cycle analysis that various classes of IT systems violate these boundary conditions. Thus, we suggest the need for metrics that include a second-law component as well as a life-cycle view of the IT system. Having identified such a metric, we demonstrate applicability of the framework for a sample IT system. We conclude by reflecting upon additional research needs and challenges associated with widespread implementation of such a framework.
Thermal Analysis of Porous Media in Passive Solar Composite
Authors: Chen Wei
Published: October 2010

In this paper, heat transfer and flow in a composite solar wall with porous absorber has been studied. The unsteady numerical simulation is employed to analyze the performance of the flow and temperature field in the composite solar wall. The excess heat is stored in the porous absorber and wall by the incident solar radiation and there is a temperature gradient in the porous layer. So, the porous absorber works as thermal insulator in a degree when no solar shining is available. The influence of the porosity within the porous absorber on the air flow in the porous absorber is significant. The results show that all these factors should be taken into account for a better design of a heating system.
Incorporating Uncertainty Into Probabilistic Performance Models of Concentrating Solar Power Plants
Authors: Ho Clifford K. , Kolb Gregory J.
Published: October 2010

A method for applying probabilistic models to concentrating solar thermal power plants is described in this paper. Benefits of using probabilistic models include quantification of uncertainties inherent in the system and characterization of their impact on system performance and economics. Sensitivity studies using stepwise regression analysis can identify and rank the most important parameters and processes as a means to prioritize future research and activities. The probabilistic method begins with the identification of uncertain variables and the assignment of appropriate distributions for those variables. Those parameters are then sampled using a stratified method (Latin Hypercube Sampling) to ensure complete and representative sampling from each distribution. Existing models of performance, reliability, and cost are then simulated multiple times using the sampled set of parameters. The results yield a cumulative distribution function that can be used to quantify the probability of exceeding (or being less than) a particular value. Two examples, a simple cost model and a more detailed performance model of a hypothetical 100 MWe power tower, are provided to illustrate the methods.
Retrospective Testing of an Automated Building Commissioning Analysis Tool (ABCAT)
Authors: Lin Guanjing , Claridge David E.
Published: October 2010

Commissioning services have proven successful in reducing building energy consumption, but the optimal energy performance obtained by commissioning may subsequently degrade. Automated Building Commissioning Analysis Tool (ABCAT), which combines a calibrated simulation with diagnostic techniques, is a simple and cost efficient tool that can help maintain the optimal building energy performance after building commissioning. It can continuously monitor whole building energy consumption, warn operation personnel when an HVAC system problem has increased energy consumption, and assist them in identifying the possible cause(s) of the problem. This paper presents the results of a retrospective implementation of ABCAT on five buildings, each of which has at least three years of post-commissioning daily energy consumption data, on the Texas A&M University campus. The methodology of ABCAT is reviewed and the implementation process of ABCAT on one building is specifically illustrated. Eighteen faults were detected in 15 building-years of consumption data with a defined fault detection standard. The causes of some of the detected faults are verified with historical documentation. The remaining fault diagnoses remain unconfirmed due to data quality issues and incomplete information on maintenance performed in the buildings.
Solid/Liquid Phase Change Heat Transfer in Latent Heat Thermal Energy Storage
Authors: Zhou D. , Zhao C. Y.
Published: October 2010

Phase change materials (PCMs) have been widely used for thermal energy storage systems due to their capability of storing and releasing large amounts of energy with a small volume and a moderate temperature variation. Most PCMs suffer the common problem of low thermal conductivity, being around 0.2 and 0.5 for paraffin and inorganic salts, respectively, which prolongs the charging and discharging period. In an attempt to improve the thermal conductivity of phase change materials, the graphite or metallic matrix is often embedded within PCMs to enhance the heat transfer. This paper presents an experimental study on heat transfer characteristics of PCMs embedded with open-celled metal foams. In this study both paraffin wax and calcium chloride hexahydrate are employed as the heat storage media. The transient heat transfer behavior is measured. Compared to the results of pure PCMs samples, the investigation shows that the additions of metal foams can double the overall heat transfer rate during the melting process. The results of calcium chloride hexahydrate are also compared with those of paraffin wax.
Long-Term Wind Speed Forecasting Based on Seasonal Trends
Authors: Kritharas Petros P. , Watson Simon J.
Published: October 2010

Over the last three decades, significant research has been carried out in the field of wind power forecasting with operational tools, however, making their presence noticeable in the last 15 years. So far, most of the work done has focused on short term forecasting of wind conditions. This is mainly due to the operational need for trading electricity a few days or a few hours ahead of gate closure due to the daily fluctuating nature of the demand and the finite response time of generation plant. However, System Operators (SOs), generators and suppliers have a need for longer term predictions of the power traded in order to maximize financial profits, schedule maintenance, etc. This paper presents a time series analysis of historical observations of wind speed in order to project future wind speed trends. The results suggest that the seasonal trend in wind speeds is the most important factor but that there is some monthly autocorrelation in the data which can improve forecasts. The approach proposed for forecasting wind speeds a month ahead may be deemed useful to suppliers for purchasing base load in advance and to SOs for power systems maintenance scheduling up to a month ahead.
Increasing Efficiencies of Thermoelectric Devices Through Angular Interface Geometries
Authors: Sellan D. P. , Amon C. H.
Published: October 2010

The phonon Boltzmann transport equation model is used to evaluate the reduction of out-of-plane thermal conductivity and subsequent increase in thermoelectric figure of merit when an angular interface is patterned between a germanium thin-film and silicon substrate. According to the acoustic mismatch model, the angular structure reduces the out-of-plane thermal conductivity by spatially redistributing phonons traveling in the out-of-plane direction. Simulation results demonstrate a 43% reduction in out-of-plane thermal conductivity when operating in the fully ballistic regime. This decrease in phononic thermal conductivity would result in an increase of intrinsic thermoelectric efficiency by a factor of 1.75.