bluuebunny/crossref_metadata_2025_split huggingface dataset:
Load levelling by control of air conditioner operation
Authors: Sasaki Hiroshi , Sadakuni Seiji 
Published: July 2007

AbstractThe recent drastic increase in the number of air conditioners has caused sharp and narrow peaks in summer seasons due to the inherent temperature‐sensitive characteristics. The authors propose a method to reduce the peak power demand by controlling air conditioner operations, and verify its effectiveness on clipping peak demand. However, former study has shortcomings in that no qualitative treatment of room temperature or comfort was attempted, and it did not provide a way of assessing peak demand clipping in a power system as a whole.In this paper, the authors propose a new control method that can deal with the maintaining of comfort and the reduction in power demand. Although air conditioners are used for “comfort,” this contradicts the reduction of power consumption and furthermore the concept of “comfort” is very vague. Hence, Weber‐Fechner's law is utilized to quantify the pleasant feeling which is treated as a fuzzy quantity. A fuzzy coordination method is used to resolve this difference between power demand curtailment and comfort.The second part of this paper prepares an approach for assessing the amount of peak load clipping when the newly proposed control strategy is adopted in a real‐size power system. A decrease in the required generation capacity is estimated provided that the loss of load probability (LOLP) is maintained at the same level before and after the application of the new control strategy. The reduction can be regarded as a dividend of load management.
Theory of fault characterization on power system
Authors: Tsuji Kouichi , Bandou Matsuo 
Published: July 2007

AbstractIn the field of protective relay, a dream which is unable to be realized by analogue technology has come true with the advance of computer technology. However, there is still room for the development of a high functional protective system, which makes the most of a merit of digital processing because the present digital relay uses the same principle as an analogous one. The points of proposed theory are that first it uses a lot of data of fault, second uses the first and second Kirchoff laws at the same time which are the starting point of electric circuit theory, and third calculates both fault location and resistance by solving nonlinear simultaneous equations.In this paper high speed calculation for protective relays is achieved by solving a compact matrix using the Newton‐Raphson method.The matrix consists of two sorts of variables (fault location, fault resistance), and the nonlinear simultaneous equation is reduced by definition of new variables.As a result of applying this theory to some real faults, we testified that the fault location error was within 0.1 percent, and the calculation time was less than 5 ms. Therefore we think that this theory has already been in a practical stage.The ultimate goal of this theory is the integration of various algorithms of protective relay, fault locator, and fault restoration operation.
Optimal power system expansion planning under uncertain CO2 emissions control policies
Authors: Fujii Yasumasa , Akimoto Keigo 
Published: July 2007

AbstractMany efforts towards a settlement of the CO2 problem have already been made through internationally organized meetings. It is not unlikely that some targets will be set for the reduction of CO2 emissions. If a stringent reduction target should be imposed on CO2 emitted from a national energy system, this can possibly have as severe an impact upon electric power sectors as the oil price crises experienced in the seventies. It is, however, quite uncertain whether or not political muscles will be used specifically for tackling the CO2 problem in the near future.In such a context, this paper presents a new method for optimal power system planning under uncertain CO2 emissions control policies. The derived optimal expansion plan gives us the minimum expected value of the sum of the total system cost and the total amount of carbon taxes levied on net CO2 emissions from fossil fuel‐fired power plants. The stochastic dynamic optimization problem discussed here is formulated as a linear programming problem decomposable into several small subproblems. The proposed method can take into account a specific future scenario of the magnitude of control policy uncertainties, which can be presumably resolved in the first half of the next century due to the increase in scientific wisdom.In order to evaluate the usefulness of the method proposed here, the authors also present a simple case study with the Japanese national power system up to the year 2050.
Development of kA‐class alternating current superconducting conductors and fabrication of a prototype coreless superconducting autotransformer
Authors: Kajikawa Kazuhiro , Kaiho Katsuyuki , Yamamoto Mitsuyoshi , Fuji Hiroshi , Sadakata Nobuyuki , Saito Takashi , Kohno Osamu 
Published: July 2007

AbstractRecently, multifilamentary superconducting wires with very low ac losses have been produced and practical applications will now be considered. To realize actualsize power machines and apparatuses, it is necessary to develop 1 ‐ 10 kA ac conductors. However, the critical currents of multifilamentary wires at 1 T are several tens of A, and therefore it is necessary to use multistrand conductors consisting of several tens or several hundreds of strands. Such conductors sometimes show ac current degradation because of such factors as (1) nonuniform current distribution, (2) wire motion, (3) temperature increase, (4) longitudinal magnetic field effect, etc.Formerly, a coreless transformer was considered unpractical because of its large exciting current. However, Yamamoto and others proposed that a coreless superconducting transformer could be used as a stepdown autotransformer at the receiving side, utilizing its large exciting current as the reactive power source to cancel the charging current of an underground transmission line or UHV line, and therefore the shunt reactors could be eliminated.In this paper, development of ac‐superconducting conductors aimed at prevention of current degradation are discussed, as well as quench test results of two small coils made with these conductors. In these conductors, low ac low strands with ultrafine NbTi filaments are twisted around a central bundle of stainless steel wires. One of the coils has been designed as a model coreless autotransformer, and its test result is also described.
Basic principles and characteristics of hybrid excitation synchronous machine
Authors: Mizuno Takayuki , Nagayama Kazutoshi , Ashikaga Tadashi , Kobayashi Tadao 
Published: July 2007

AbstractPermanent magnet type synchronous machines have been widely used for industrial applications. It is commonly known that they are operated at high efficiency since no excitation input is required. However, it is difficult to control the air‐gap magnetic flux, because the magnetic flux is determined by the property of the permanent magnet and approximately kept constant.On the other hand, synchronous machines with the field winding make it easy to control the air‐gap magnetic flux. But the copper loss of the field winding becomes large at the rated load.In order to realize the magnetic flux control easily and improve the performance of the conventional synchronous machine, we propose a hybrid excitation type synchronous machine (HSY) with the permanent magnets and the field winding. Advantages of HSY are (1) it has no brushes (maintenance free), (2) required excitation input is small (high efficiency), (3) it is easy to get a sufficient magnetic flux control, and others. Therefore, HSY has a great possibility of use for various applications.In this paper, basic principles and characteristics of HSY are mainly discussed and made clear.
The Fluorescence Labelling of Primary Amines with Perylenetetracarboxdiimides
Authors: Langhals Heinz , Becherer Thomas , Lindner Jörg , Obermeier Andreas 
Published: July 2007

AbstractThe synthesis of perylenetetracarboxdiimide‐labelled aldehydes is described as well as their condensation with primary amines. Thus, a highly fluorescent and light‐fast fluorescence labelling process has been demonstrated. Application of this method to biological targets is also reported. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Thermokinetic Analysis Reveals the Complex Growth and Haloadaptation Pattern of the Non‐Conventional Yeast Debaryomyces hansenii
Authors: Schumer D. , Breuer U. , Harms H. , Maskow T. 
Published: July 2007

AbstractThe high halotolerance, simple cultivation, potentially easy downstream processing together with a broad substrate spectrum raises growing interest in the non‐conventional oleaginous yeast Debaryomyces hansenii as a cell factory for the chemical and food industry. Moreover, the potential of non‐conventional yeasts for the decontamination of the environment and as possible hosts for biosensor developments are still unexplored. However, non‐conventional yeasts often respond in a highly complex manner to unfavorable conditions. Exploiting the potential of these yeasts on a technical scale requires the development and testing of robust monitoring tools providing deeper and real‐time insight into metabolism. Calorimetry is ideal for this particular process since it measures the entirety of metabolic processes, while indicating changes immediately and allowing the quantitative description of regulatory processes when combined with further online and offline analytics. Furthermore, recent calorimetric developments promise applicability under technical “dirty” conditions and suitability for high‐throughput measurements. To demonstrate the analytical potential of calorimetry for the characterization of the highly complex yeast metabolism, the heat production rate and the dynamics of key metabolites were assayed at different salinities. Strong correlations between these features were observed, and the complex heat pattern reflected the dynamics of key metabolites quantitatively.
Optimal bank asset and liability management with financial futures
Authors: Brodt Abraham I. 
Published: July 2007

AbstractThis paper presents a model for optimal bank asset and liability management with financial futures. This model is a multiperiod linear programming model based on Markowitz portfolio theory. Given the bank's initial position, its economic forecasts, and the constraints under which it operates, the model can help a bank's senior executives determine the current and expected future balance sheet composition and financial futures position which will minimize the bank's operating risks and which will meet the bank's expected profits goal with the minimum possible profits risk. By parametrically varying the expected profits goal, the model will generate the set of risk‐return efficient decisions. Bankers need then examine only the set of efficient decisions to choose their optimal solution.A simplified example is used to illustrate the application of our model and to demonstrate that banks that use financial futures in asset and liability management can obtain better results than banks that do not use financial futures.
Quality of life in patients older than 75 years following major head and neck surgery
Authors: Khafif Avi , Posen Jennie , Yagil Yaron , Beiser Michael , Gil Ziv , Ben‐Yosef Rami , Landsberg Roee , Fliss Dan M. 
Published: July 2007

AbstractBackground.This study was designed to evaluate the quality of life (QOL) of patients older than 75 years undergoing major head and neck surgery.Methods.Three groups of patients were included: elderly patients (>75, n = 35) and younger patients (65 to 75 years, n = 30) undergoing major head and neck surgery and healthy controls (>75, n = 40). Measurements were made using the SF‐12 health survey, the University of Washington QOL questionnaire, and measurements of the “sense of burden” on the caregiver.Results.With the SF‐12, the role physical, role emotional, and bodily pain were decreased by the surgical intervention, while physical function was affected by age alone. With the UW‐QOL Questionnaire, overall QOL was preserved. “Appearance” and “Leisure” subscales were affected by the surgical intervention and old age. “Chewing” and “Activity” were decreased by the surgical intervention in the older patients, and “Speech” was affected by the surgical intervention alone. The “sense of burden” was alleviated by surgery in the elderly patients.Conclusions.Several QOL domains are decreased in elderly patients undergoing major head and neck surgery. © 2007 Wiley Periodicals, Inc. Head Neck 2007
Inhibitory effect of Zn2+ in zinc‐containing β‐tricalcium phosphate on resorbing activity of mature osteoclasts
Authors: Yamada Yasutaka , Ito Astuo , Kojima Hiroko , Sakane Masataka , Miyakawa Shumpei , Uemura Toshimasa , LeGeros Racquel Z. 
Published: July 2007

AbstractLong term effect of the growing instability of the bone‐implant interface due to bone resorption at the interface is a problem for the implants, including bioactive ceramics. Zn2+‐containing tricalcium phosphate (ZnTCP) is a material which may overcome this problem. The present study aims to clarify whether Zn2+‐containing tricalcium phosphate (ZnTCP) ceramics with a Zn2+ content of 0.316 (ZnTCP316) and 0.633 (ZnTCP633) wt % suppress resorption by mature osteoclasts in vitro. Suppression would be due to an increase in the number of apoptotic osteoclasts and the inhibition of the resorbing activity of osteoclasts, the latter being the major mechanism of the suppression. The number of apoptotic osteoclasts was significantly 6.3 times higher with ZnTCP633 than with tricalcium phosphate ceramic (TCP) after 24‐h culture. The net contribution to resorption of this change in apoptotic cell numbers is much smaller than that of the change in resorbing activity. The osteoclasts cultured on ZnTCP formed fewer actin rings than those cultured on the TCP. The mRNA expression of CAII and cathepsin K/OC2 in the osteoclasts on ZnTCP633 was downregulated 0.5‐fold and 0.6‐fold, respectively, compared with that on the TCP. The volume of resorption pits was downregulated 0.4‐fold in the ZnTCP633 than that in TCP. These results suggest that ZnTCPs suppressed the resorbing activity of mature osteoclasts probably through a local increase in the level of Zn2+. Bone substitutes or coating layers containing ZnTCP would be promising biomaterials from the viewpoint of counteracting osteoclastic bone resorption at the bone‐implant interface. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Amorphous and crystalline polyetheretherketone: Mechanical properties and tissue reactions during a 3‐year follow‐up
Authors: Nieminen Tuomo , Kallela Ilkka , Wuolijoki Erkki , Kainulainen Heikki , Hiidenheimo Ilmari , Rantala Immo 
Published: July 2007

AbstractThe study was aimed to test the mechanical strength, structural stability, and tissue reactions of optically amorphous and crystalline polyetheretherketone (PEEK) plates during a 3‐year follow‐up in vivo and in vitro. The injection‐moulded PEEK plates were implanted to the dorsal subcutis of 12 sheep, which were sacrificed at 6–156 weeks. Thereafter, the plates were subjected to tensile tests, and levels of crystallinity were assessed by differential scanning calorimetry (DSC). Histological evaluation was carried out using the paraffin technique. In vitro properties were examined with the tensile test and DSC at 0–156 weeks. Tissue reactions were mild and fairly similar for the amorphous and crystalline plates at corresponding points in time. The mechanical characteristics of the plates remained stable over the entire follow‐up. The tensile yield load and elongation at the yield load of the crystalline plates were roughly double (∼500 vs. 270 N and 2.4 vs. 1.4 mm, respectively) in comparison to the amorphous plates. The elongation at break load of the crystalline plates was smaller than that of the amorphous ones (6 vs. 10). The level of crystallinity in both the optically amorphous (∼15%) and crystalline (32–34%) plates remained invariable during the follow‐up. The in vitro and in vivo data coincided remarkably well. In conclusion, both optically amorphous and crystalline PEEK plates are suitable for the fixation of fractures and osteotomies. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Titanium with aligned, elongated pores for orthopedic tissue engineering applications
Authors: Spoerke Erik D. , Murray Naomi G.D. , Li Huanlong , Brinson L. Catherine , Dunand David C. , Stupp Samuel I. 
Published: July 2007

AbstractPorous titanium with elongated and aligned pores, mimicking the anisotropic structure of bone, was created by solid‐state expansion of argon trapped in elongated pores between titanium wires. Both elastic moduli and yield strengths are larger in the longitudinal direction (E = 51 GPa, σy = 338 MPa) than in the transverse direction (E = 41 GPa, σy = 267 MPa). Finite‐element analysis of simplified anisotropic structures provides insight into the local micromechanical behavior of these porous materials, evaluating elastic modulus, resistance to plastic deformation, and localized stress concentrations which may be experienced under biological loading. Preliminary in vitro cell culture studies further demonstrate the influence of the elongated porous microstructure on osteoblast colonization behavior. These studies suggest that as an optimized material, titanium with aligned, elongated pores is promising for applications in orthopedic tissue engineering, as it combines high strength, toughness, and biocompatibility of titanium with the reduced stiffness and open porosity suitable for mechanical integration with bone tissue produced by aligned pores. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Amidic alginate hydrogel for nucleus pulposus replacement
Authors: Leone Gemma , Torricelli Paola , Chiumiento Antonio , Facchini Alessandro , Barbucci Rolando 
Published: July 2007

AbstractDegeneration of intervertebral discs is the most common cause of back pain. The first phase of this degenerative process involves the nucleus pulposus (NP). A rapid recovery of this structure can prevent further degradation of the annulus fibrosus. A new amidic derivative of alginate (AAA) was developed to obtain a polysaccharide possessing some of the physical–chemical properties of Hyal (i.e. viscosity) without losing the rigidity of the native alginate structure. The modified polysaccharide was crosslinked using 1.3 diaminopropane as crosslinking agent. The hydrogel obtained was characterized in terms of water uptake and rheological behavior. In particular, the viscoelastic behavior of the hydrogel was determined in shear stress under dynamic conditions and compared with the behavior of nondegenerated human lumbar NP. We then assessed the effect of the AAA hydrogel on NHC (Normal Human Chondrocyte) cell viability and on the production of important extracellular matrix factors, such as glycosaminoglycans and Type II collagen. In conclusion, the results achieved in this study demonstrated that the amidic alginate‐based scaffold is a promising material to be utilized in the replacement of NP. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Bone cell responses to the composite of Ricinus communis polyurethane and alkaline phosphatase
Authors: Beloti Marcio Mateus , de Oliveira Paulo Tambasco , Tagliani Marcela Martini , Rosa Adalberto Luiz 
Published: July 2007

AbstractThe aim of this study was to evaluate the response of osteoblastic cells to the composite of Ricinus communis polyurethane (RCP) and alkaline phosphatase (ALP) incubated in synthetic body fluid (SBF). RCP pure (RCPp) and RCP blended with ALP 6 mg/mL polymer (RCP+ALP) were incubated in SBF for 17 days. Four groups of RCP were tested: RCPp, RCP+ALP, and RCPp and RCP+ALP incubated in SBF (RCPp/SBF and RCP+ALP/SBF). Stem cells from rat bone marrow were cultured in conditions that allowed osteoblastic differentiation on RCP discs and were evaluated: cell adhesion, culture growth, cell viability, total protein content, ALP activity, and bone‐like nodule formation. Data were compared by ANOVA or Kruskal–Wallis test. The group RCP+ALP was highly cytotoxic and, therefore, was not considered here. Cell adhesion (p = 0.14), culture growth (p = 0.39), viability (p = 0.46) and total protein content (p = 0.12) were not affected by either RCP composition or incubation in SBF. ALP activity was affected (p = 0.0001) as follows: RCPp < RCPp/SBF < RCP+ALP/SBF. Bone‐like nodule formation was not observed on all evaluated groups. The composite RCP+ALP prior to SBF incubation is cytotoxic and must not be considered as biomaterial, but the incorporation of ALP to the RCP followed by SBF incubation could be a useful alternative to improve the biological properties of the RCP. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Silklike materials constructed from sequences of Bombyx mori silk fibroin, fibronectin, and elastin
Authors: Yang Mingying , Tanaka Chikako , Yamauchi Kazuo , Ohgo Kosuke , Kurokawa Masato , Asakura Tetsuo 
Published: July 2007

AbstractTwo silklike proteins, [TGRGDSPAGG(GAGAGS)3AS]5 (FS5) and [TGRGDSPA‐(GVPGV)2GG(GAGAGS)3AS]8 (FES8) were designed to demonstrate the superior performance as biomaterials of silklike proteins. The former protein consists of the crystalline domain sequence, (GAGAGS)n from Bombyx mori silk fibroin and cell‐adhesive sequence TGRGDSPA coming from fibronectin‐containing RGD triplet. The additional sequence (GVPGV)n from elastin was included in the latter protein. The considerably higher cell‐adhesion activities of these proteins for NHDF and VERO cells were observed by comparing with those of silklike materials without RGD sequences and also the crystalline fraction of B. mori silk fibroin. This tendency was independent of the treatments, 4.5M LiClO4 or formic acid (FA), on silklike proteins. Their activities are also higher than those of commercial Fibronectin F™ for NHDF cell. Their structural characterization was studied using 13C solid‐state NMR. Although the overlapped peaks in usual 13C CP/MAS NMR spectra make the detailed structural analysis difficult, the methyl resonance regions observed using dipolar dephasing NMR were very useful for the analysis. The presence of both random coil and β‐sheet structures was observed in these proteins clearly. The content of β‐sheet structure in both proteins increases after FA treatment when compared with the lyophilized samples. The production of electrospun nanofibers from their hexafluoroacetone solution was also tried. The silklike protein FES8 could prepare nonwoven silk fibers although FS5 could not. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Preparation of fibroin/recombinant human‐like collagen scaffold to promote fibroblasts compatibility
Authors: Hu Kun , Cui Fuzhai , Lv Qiang , Ma Jun , Feng Qingling , Xu Li , Fan Daidi 
Published: July 2007

AbstractRecombinant human‐like collagen (RHLC) was added to fibroin solution to prepare a novel hybrid scaffold material for skin tissue engineering. The morphology of the scaffold had highly homogeneous and interconnected pores with pore sizes 136 ± 32 μm measured by scanning electron microscopy (SEM). FTIR analysis indicated intermolecular crosslinkages between fibroin and RHLC formed. The viscosity of the blend solution increased because of the interaction between fibroin and RHLC, and then it restrained the unwanted fibroin aggregation in freezing process that generally appeared in fibroin scaffold preparation with freeze drying method. After methanol treatment the fibroin/RHLC scaffold became water‐stable. The porosity of scaffolds was ≫90%, the compressive strength and modulus were up to 662 ± 32 KPa and 7.8 ± 0.64 MPa, respectively. Fibroblasts cultured within fibroin/RHLC scaffolds were investigated by SEM, laser scanning confocal microscopy (LSCM), and MTT assay, which showed that the adding of RHLC significantly enhanced the cells adhesion, proliferation, and viability compare with fibroin scaffolds. These results suggest that the hybrid scaffolds have favorable characteristics for skin tissue engineering. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008