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Selected AbstractsOptimal CBM of tie lines between control areas in a deregulated environmentELECTRICAL ENGINEERING IN JAPAN, Issue 1 2009Hideaki Kuraishi Abstract In order to keep power supply reliability at a certain level, electric power utilities have a certain amount of reserve capacity. When no generator outage or no unexpected large power demand occurs, however, the reserve capacity is regarded as surplus facility. To reduce the reserve capacity, some margin is reserved in tie lines between utilities. This margin is called the capacity benefit margin (CBM). In this study, a method of calculating optimal CBM in tie line under deregulated environment is described and two kinds of optimal CBM are proposed. As a result, it is shown how the deregulation affects the optimal CBM by using numerical simulation for the IEE Japan West 30 test system. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(1): 35, 48, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20654 [source] Preparation, Electrochemistry, and Electrocatalytic Activity of Lead Pentacyanonitrosylferrate Film Immobilized on Carbon Ceramic ElectrodeELECTROANALYSIS, Issue 21 2008H. Razmi Abstract Lead pentacyanonitrosylferrate (PbPCNF), a new Prussian blue analog, was immobilized on the surface of a carbon ceramic electrode (CCE) prepared by sol-gel method. The immobilization process consists of adding a certain amount of metallic lead to the electrode matrix before gelation, and chemical derivatization of Pb on the electrode surface to a PbPCNF solid film by immersing the electrode in a solution of sodium pentacyanonitrosylferrate (PCNF). The composition of the synthesized PbPCNF was characterized by FTIR, scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) techniques. The resulting modified electrode showed electroactivity at two redox centers. The electrochemical behavior of the PbPCNF modified carbon ceramic electrode (PbPCNF|CCE) was studied by cyclic voltammetry. Under optimized conditions the peak-to-peak separation is only 39,mV, indicative of a surface reaction. Ion effects of the supporting electrolyte suggest that cations have a considerable effect on the electrochemical behavior of the modified electrode. The transfer coefficient (,) and the charge transfer rate constant at the modifying film|electrode interface (ks) were calculated. The electrocatalytic activity of the modified electrode toward the electro-reduction of peroxodisulfate was studied in details. [source] Hesitantly into the arena: An account of trainee teachers' and sixth form students' preliminary attempts to enter into dialogue through emailENGLISH IN EDUCATION, Issue 3 2009Nicholas McGuinn Abstract Teacher training is increasingly accountable to central government. Trainees , the word itself is significant , are expected to demonstrate competence in a wide range of professional standards if they are to achieve qualified teacher status. Training partnership schools, understandably, impose their own conditions for entry into their ,communities of practice'. In these circumstances, trainees , and their trainers , have increasingly fewer opportunities for risk taking or for exploring new configurations of the teacher pupil relationship. This paper describes an attempt to exploit the potential of email as a means of granting access to a ,pedagogical arena' in which trainees and students might attempt to negotiate their own ways of working together. It concludes by suggesting that both groups found this a challenging task and by noting that the trainers involved decided that, if the project were to run again, a certain amount of autonomy would need to be sacrificed to direction. [source] Cobalt-Catalyzed C,N Bond-Forming Reaction between N-Aromatic 2-Chlorides and Secondary AminesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 27 2009Gabriel Toma Abstract Secondary amines react with N-aromatic 2-chlorides in the presence of a catalytic amount of cobalt chloride. When DPPP was added as ligand, the yield was further improved. The N-aromatic-containing tertiary amines formed are interesting due to their potential biological activity. This work represents the first cobalt-catalyzed approach to C,N bond formation involving N-aromatic 2-chlorides and secondary amines having a certain amount of versatility and functional group tolerance.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Critical appraisal of the mouse model of myocardial infarctionEXPERIMENTAL PHYSIOLOGY, Issue 4 2004Naomi M. Degabriele In order to critically evaluate the utility of a mouse model of myocardial infarction (MI) for therapeutic studies, we investigated survival, haemodynamic measurements and histopathology in mice with an occluding suture placed at one of three distinct sites along the left anterior descending coronary artery. The suture was placed at the atrioventricular juncture (High), or at two sites more distally towards the base (Middle and Low). In the High group, only 33% of animals survived 7 days after MI (P < 0.05 compared to all other groups). Only the Middle group had significantly reduced haemodynamics compared to sham-operated animals (maximum left ventricular pressure: 55.9 ± 3.5 versus 80.8 ± 5.1 mmHg, maximum change in pressure over time : 2003 ± 172 versus 4402 ± 491, P < 0.01). Histological examination showed morphological changes in all MI groups. The Middle group had larger lesions than the Low group (P < 0.05). Lesions in the anterior and lateral walls correlated, albeit weakly, with cardiac function. Power calculations indicated that, despite a certain amount of intragroup variation, the Middle Suture model may be useful for therapeutic studies to assess the effects of treatment on cardiac function and overall lesion size. [source] Safety evaluation of sewage-sludge-derived fuels by comparison with other fuelsFIRE AND MATERIALS, Issue 4 2009Xin-Rui Li Abstract The utility of sewage sludge as a biomass fuel is taken as a new approach to recycle unwanted wastes as renewable energy and deal with global warming. However, safety caring of this new type of fuel is a premise before it is practically used in boilers. Thermal behaviors of four sludge-derived fuels which are under development were examined by several calorimeters (such as thermogravimetry/differential thermal analysis, C80 and thermal activity monitor) at temperature ramp and isothermal conditions. Heat generation at relatively low temperatures was observed. The corresponding spontaneous ignition was detected in an adiabatic spontaneous ignition tester at 80,C in some sludge species. Moreover, a certain amount of gaseous evolution was accompanied when the sludge fuels were stored at room temperature and at 60,C. Oxidation is mainly responsible for the heat and gas release from the sludge fuels. The hazards of the sewage sludge fuels were also compared with a bituminous coal and a refuse-derived fuel, which have the main feature of spontaneous ignition. Copyright © 2009 John Wiley & Sons, Ltd. [source] French Views on Thatcherism and BlairismHISTORICAL RESEARCH, Issue 182 2000Jacques Leruez The French like terms ending in ,ism', especially when they appear to represent a substantial ideological proposition or, at the very least, a definite change in the methods of governance. Thus, both Thatcherism and Blairism have held considerable interest for both the educated public and the media. If Thatcherism was generally condemned as reactionary, there was none the less a certain amount of admiration for Lady Thatcher's ,conviction'. As for Blairism, while considered a betrayal of socialist ideals by the more traditional left wing, it is looked upon with some sympathy in centrist and even right-wing circles. [source] Corrosion control by antioxidant DBPC in insulating oilIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 3 2009Takashi Ito Non-member Abstract In order to evaluate corrosive sulfur in insulating oil quantitatively, wave length dispersive X-ray (WDX) technique has been reported 1. Using this technique, antioxidant 2,6-di- tert -butyl- p -cresol (DBPC) was found to be effective to suppress corrosion caused by dibenzyl disulfide (DBDS). The effect of corrosion prevention continues for a long term when a certain amount of DBPC is added to oil. The durability of DBPC was also evaluated by HPLC. It is possible to add relatively a good deal of DBPC to oil because DBPC has higher solubility than passivator and little effect on dielectric strength. Furthermore, DBPC was used with passivator simultaneously, and corrosion control time was far extended by their synergy effect. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] Withdrawal behavior and depression in infancyINFANT MENTAL HEALTH JOURNAL, Issue 4 2007Antoine Guedeney This paper describes the history of the concept of infant depression, which has been at the beginning of the discipline of infant mental health, and reviews classification and diagnosis issues, along with some animal models. Several diagnostic criteria have yielded different prevalence rates, and some being unrealistic, but we still do not know when infant depression begins, what its outcome is, and what are its different aspects. It is suggested that infant depression needs a certain amount of emotional and cognitive development to unfold, and that it might not exist before 18,24 months of age, a crossover during which major autoreflexive, cognitive, and emotional abilities emerge. Depression could be an outcome of attachment disorganization in infancy, as depression and disorganization seem to share the same learned helpnessness psychopathological process. Developmental psychopathology considers trouble more from a dimensional point of view rather than from a categorical one, and more as the result of several factors with a sequential action rather than the effect of a genetic disorder with direct expression. Before the limit of 18,24 months, the concept of relational withdrawal seems more applicable and useful. [source] Continental-scale phenology: warming and chillingINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 11 2010Mark D. Schwartz Abstract With abundant evidence of recent climate warming, most vegetation studies have concentrated on its direct impacts, such as modifications to seasonal plant and animal life cycle events (phenology). The most common examples are indications of earlier onset of spring plant growth and delayed onset of autumn senescence. However, less attention has been paid to the implications of continued warming for plant species' chilling requirements. Many woody plants that grow in temperate areas require a certain amount of winter chilling to break dormancy and prepare to respond to springtime warming. Thus, a comprehensive assessment of plant species' responses to warming must also include the potential impacts of insufficient chilling. When collected at continental scale, plant species phenological data can be used to extract information relating to the combined impacts of warming and reduced chilling on plant species physiology. In this brief study, we demonstrate that common lilac first leaf and first bloom phenology (collected from multiple locations in the western United States and matched with air temperature records) can estimate the species' chilling requirement (1748 chilling hours, base 7.2 °C) and highlight the changing impact of warming on the plant's phenological response in light of that requirement. Specifically, when chilling is above the requirement, lilac first leaf/first bloom dates advance at a rate of , 5.0/, 4.2 days per 100-h reduction in chilling accumulation, while when chilling is below the requirement, they advance at a much reduced rate of , 1.6/, 2.2 days per 100-h reduction. With continental-scale phenology data being collected by the USA National Phenology Network (http://www.usanpn.org), these and more complex ecological questions related to warming and chilling can be addressed for other plant species in future studies. Copyright © 2009 Royal Meteorological Society [source] Split agent-based routing in interconnected networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 4 2004Constandinos X. Mavromoustakis Abstract Adaptive behaviour of swarm-based agents (BT Technol. J. 1994; 12:104,113; AAMAS Conference '02, Melbourne, Australia, Month 1,2, 2002; Softcomput. J. 2001; 5(4):313,317.) is being studied in this paper with respect to network throughput for a certain amount of data traffic. Algorithmically complex problems like routing data packets in a network need to be faced with a dynamically adaptive approach such as agent-based scheme. Particularly in interconnected networks where multiple networks are participating in order to figure a large-scale network with different QoS levels and heterogeneity in the service of delay sensitive packets, routing algorithm must adopt in frequent network changes to anticipate such situations. Split agent-based routing technique (SART) is a variant of swarm-based routing (Adapt. Behav. 1997; 5:169,207; Proceedings of 2003 International Symposium on Performance Evaluation of Computer and Telecommunication Systems,SPECTS, Montreal, Canada, July 20,24, 2003; 240,247.) where agents are split after their departure to the next node on a hop-by-hop basis. Packets that are delay sensitive are marked as prioritized which agents recognize-as being a part of a packet- and try to influence the two-way routing tables. Thorough examination is made, for the performance of the proposed algorithm in the network and the QoS offered, taking into account a number of metrics. It is shown that the split agent routing scheme applied to interconnected networks offers a decentralized control in the network and an efficient way to increase overall performance and packet control reducing at the same time the packet loss concept. Copyright © 2004 John Wiley & Sons, Ltd. [source] Determination of ,, solution temperature in Re-rich Ni-base superalloy by small-angle neutron scatteringJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 5 2001Pavel Strunz A harmful segregation of heavy elements (e.g. W, Mo, Re) during solidification of Ni-base superalloys can only be eliminated by using a homogenizing heat treatment, which needs to be carried out in the single-phase (,) field above the ,, solvus temperature but below the solidus temperature. Small-angle neutron scattering (SANS) was employed for in situ observation of the dissolution of precipitates in an Re-rich superalloy. The temperature dependence of the relative volume fraction and the size distribution of smaller ,, precipitates, and the specific surface of large inhomogeneities as well as some other parameters were determined from the two-dimensional scattering curves measured for as-cast and heat-treated samples. Overlap of the incipient melting region with the region where a certain amount of precipitates remained undissolved was observed, thus complicating a determination of the temperature at which all ,, precipitates are already dissolved. Nevertheless, conclusions about the temperature at which the precipitates dissolve and about the temperature at which the incipient melting starts could be formulated. The total scattering probability is suggested as the measure of the overall homogeneity of the distribution of elements in the sample. The temperature dependence of this parameter indicates the optimum solution procedure. [source] Contrast analysis of the composition of ribosomes extracted with different purification proceduresJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 4 2000Giuseppe Briganti The composition and hydration of E. coli ribosomes isolated with different purification protocols has been analysed by combining two experimental techniques: measurements of small-angle neutron scattering (SANS), for two different isotopic solvent compositions, and refractive index (RI) increments. From the contrast between the solvent and solute scattering densities and the molar polarizability, determined experimentally with SANS and RI measurements, three independent equations are obtained and three unknown quantities are determined: (i) the volume of the solute hydrated skeleton Vs, (ii) the material contained in it, namely the biological components, intrinsic (rRNA and proteins) and extrinsic, such as aminoacylsynthetase and elongation factors, (iii) the number of water molecules structurally bound to the ribosome and non-exchangeable with the solvent. From the form factor at infinite contrast, a second definition of the solute volume is obtained, , which represents the volume within the contour surface of the ribosome. This value is generally larger than Vs and can include a certain amount of water molecules, i.e. those inside the volume (,Vs). Considering the molar volume of this water to be equal to that of the bulk water, it is possible to evaluate its amount. The particle density calculated from the ribosome components in , including proteins, RNA, bound and unbound water molecules, corresponds to the buoyant density measured for E. coli 70S particles. The two ribosomal preparations display different performances in protein synthesis; hence the results indicate that the optimal condition corresponds to a wider skeleton and contour volume but containing a smaller amount of segregated water molecules. It is believed that the method provides a reliable technique to determine the composition of ribosomes under various experimental conditions. [source] A new technique for foaming submicron size poly(methyl methacrylate) particlesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2007Hiroyuki Ogawa Abstract About 0.7,2 ,m diameter poly (methyl methacrylate) (PMMA) foamed particles were prepared via thermally induced phase separation (TIPS) from a PMMA/ethanol mixture and vacuum dried. It was found that ethanol, known to be a poor solvent to PMMA, could dissolve PMMA when the temperature was over 60°C. The solubility of PMMA (Mw = 15,000 and Mw = 120,000) in ethanol was measured and was found to increase as the temperature increased. PMMA particles on the scale of submicron and single micron diameter could be precipitated from the PMMA/ethanol solution by temperature quenching. Then, since the precipitated particles contained a certain amount of ethanol, the precipitated particles could be foamed using the ethanol as a foaming agent in a vacuum drying process. Vacuum drying at temperatures slightly below the glass transition temperature of the polymer could make the particles foam. The effects of foaming temperature and the molecular weight of the polymer on the size of foamed particles were investigated. The experimental results showed that the vapor pressure and the molecular weight of the polymer are key factors determining the expandability of the micro particles. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 [source] STABILITY OF ANTHOCYANINS, PHENOLS AND FREE RADICAL SCAVENGING ACTIVITY THROUGH SUGAR ADDITION DURING FROZEN STORAGE OF BLACKBERRIESJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 2009MIRELA KOPJAR ABSTRACT Influence of sugar and mixtures of sugar on color retention of two varieties of blackberries, Thornfree and Cacanska bestrna, were investigated during storage at ,18C for 12 months. After harvest, blackberries were coated with sugars (sucrose, fructose and glucose) and different sugar (sucrose + fructose + glucose, fructose + glucose, fructose + sucrose) mixtures. Anthocynin content, total phenol content and free radical scavenging activity of prepared samples were evaluated. Ratio of fruit : sugar was 1:1. The highest anthocyanin retention was in blackberry samples with glucose addition and the lowest in samples with sucrose addition, in both cultivars. Blackberry samples with sucrose addition had even lower retention than samples without sugar addition. Samples with an addition of other sugars had higher retention of anthocyanin than samples stored without sugars. PRACTICAL APPLICATION Possibility of phenols retention of blackberries due to sugar addition, during cold storage was investigated. Results showed that glucose had the most positive effect on anthocyanins retention as well as total phenolic compounds content. For that reason, certain amount of sucrose in fruit preserves can be replaced by addition of glucose, and for that reason retention of phenolic compounds can be higher and, as could be expected, more effective against oxidative stress in human body due to intake of product formulation with glucose. [source] PROPOSED NEW COLOR RETENTION METHOD FOR TILAPIA FILLETS (O. NILOTICUS, × O. AUREUS,) BY EUTHANATIZING WITH REDUCED CARBON MONOXIDEJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 5 2008LAIHAO LI ABSTRACT The conditions of color retention for tilapia fillets (O. niloticus, × O. aureus,) treated by euthanatizing with reduced carbon monoxide (CO) were investigated. Live tilapias were first exposed to water saturated with CO. After a certain amount of CO-saturated water had been pumped through the gills, the tilapias were timely picked out and killed following the industry guidelines. The color value of fillets was measured by colorimeter to evaluate the color retention. The results showed that (1) temperature did not have a significant effect on the color of the fillets; (2) the optimal conditions were a ratio of 3:1, v/w between water and fish, a CO flow rate of 80 mL/min and 10 min CO injection followed by 5 min air exposure. Under these conditions, a higher a*value (redness 19.44) and a better sensory evaluation value (4.8) were obtained; and (3) the proposed method shortened processing time by 30,35 min, reduced the frequency of sterilization to only once, significantly lowered microbial counts from 82.33 × 102 to 56.33 × 102 and reduced the CO requirement 25-fold, which has significant occupation, health, safety, and environmental implications. PRACTICAL APPLICATIONS Color retention for tilapias is conventionally accomplished by treating fillets with CO. Recently, euthanatizing tilapias with CO has been assumed to be an effective way to shorten processing time and to lessen product handling process. Many factories have been searching for a way to solve the problem of color retention for tilapias or other red muscle treatment, but there has been a lack of information on how euthanasia affects fish quality, especially red muscle color. The objective of this experiment was to explore the application of the new method. [source] The effectiveness of antipsychotic medication in the management of behaviour problems in adults with intellectual disabilitiesJOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 10 2007S. Deb Abstract Background Psychopharmacological intervention in the management of behaviour problems in adults with intellectual disabilities (ID) has become a common treatment strategy. This has become a cause for concern, given that the evidence for its effectiveness is uncertain and most drugs are not licensed for this use. Methods A comprehensive systematic review of empirical research on the effectiveness of antipsychotic medication was conducted. Electronic and manual searches of literature were conducted. Stringent scientific methodology determined those primary trials that were worthy of inclusion. Results This review revealed one randomized controlled trial (RCT), one controlled, four uncontrolled prospective and three retrospective case series studies in adults. Additionally, two studies in both adults and children , one crossover RCT and one prospective controlled trial , were found. Conclusion Presently, there is RCT-based evidence for risperidone to be effective in both adults and children; however, this treatment carries a certain amount of risk associated with adverse effects. There is also evidence to support the use of other antipsychotics, primarily atypicals, but the evidence is based on noncontrolled case studies. There is currently not enough evidence available to recommend specific medication for specific behaviour problems. Before prescribing medication, clinicians should carry out a thorough assessment of behaviour, including its causes and consequences, and draw up a formulation providing the rationale for the prescribed intervention after considering all medication- and nonmedication-based management options. [source] Four-year study of cobalt and chromium blood levels in patients managed with two different metal-on-metal total hip replacementsJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 2 2003Christian Lhotka Abstract Background: Metal-on-metal total hip prostheses will produce a certain amount of wear debris. This results in increased whole-blood metal levels, which may cause adverse effects. It is not known to what extent the problem has been overcome by advances in alloy technology. Methods: In 259 patients who with total hip replacement, blood cobalt and chromium concentrations were measured with atomic absorption spectrophotometry over a period of four years after arthroplasty. Of the patients enrolled in the study, 131 had been managed with a METASUL® cobalt-chromium alloy metal-on-metal bearing combination, while 128 had been given a SIKOMET®-SM21® cobalt-chromium alloy metal-on-metal combination. The control group consisted of 31 age- and gender-matched subjects. Results: Compared with the controls, all the patients had higher cobalt and chromium levels. Cobalt concentrations were up to 50 times higher, while chromium concentrations were up to 100 times higher. Conclusions: Both systems showed evidence, in the whole-blood samples, of wear debris production by the implants. Therefore, patients managed with metal-on-metal bearing combinations should be carefully monitored in order to ensure that any local or systemic complications are detected early on. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source] Phosphatidylethanol and Alcohol Consumption in Reproductive Age WomenALCOHOLISM, Issue 3 2010Scott H. Stewart Background:, Fetal alcohol disorders are preventable, but self-reported alcohol consumption can be misleading and impede effective treatment. Biomarkers represent an alternative method for assessing alcohol use, and this study evaluated the relationship between blood phosphatidylethanol (PEth) and alcohol use in a sample of reproductive age women. Methods:, Alcohol use was estimated by validated self-report methods in 80 nonpregnant women ages 18 to 35. PEth was measured by a contracted laboratory using a liquid chromatography-tandem mass spectrometry assay. Regression methods appropriate for the distribution of PEth were used to define its relationship to alcohol consumption during the prior 2 weeks and explore the effects of drinking patterns on this association. Receiver operating characteristic analysis was used to estimate the sensitivity of PEth for various drinking levels at 95% specific cutoffs. Results:, PEth had a positive linear association with grams of alcohol consumed (p < 0.001), and was detectable in 93% of subjects consuming an average of 2 or more drinks per day. The relationship between total alcohol consumption and PEth may be stronger in women with recent heavy drinking days. The relationship between drinking and PEth varied considerably between individuals, and sensitivity for a certain amount of drinking was low at a highly specific cutoff concentration. Conclusions:, PEth is a highly sensitive indicator of moderate and heavy alcohol consumption in reproductive age women and may complement the use of self-report alcohol screens when additional objective markers of alcohol use are desirable. However, choosing a highly valid cutoff concentration for PEth to differentiate various levels of alcohol consumption may not be feasible. [source] Synthesis and characterization of secondary-amine-functional microparticlesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 15 2004E. Banu Altinta Abstract Secondary-amine-functional microparticles were prepared in the range of 50,250 ,m through the suspension polymerization of styrene, divinylbenzene (DVB), and 2-(tert -butylamino)ethyl methacrylate (tBAEMA). This study focused on the effects of the DVB, tBAEMA, initiator, and stabilizer concentrations and shaking rate on the experimental amine content, swelling ratio, average particle size, and particle size distribution. The suspension polymerization experiments were carried out in two different systems. In the first system, an organic phase, including the monomers and initiator, was dispersed in an aqueous medium in the presence of Al2(SO4)3. Al2(SO4)3, in the presence of an amine monomer (pH , 10), formed colloidal Al(OH)3, which built a nonsticky layer on the surface of the polymerizing droplets that prevented them from coalescing and aggregating. Individual and spherical particles within the range of 50,200 ,m were obtained by this polymerization method. The second method was similar to the first polymerization protocol, except that a certain amount of sodium dodecyl sulfate was added as a costabilizer in the presence of Al2(SO4)3. In these experiments, individual and spherical particles were obtained within the range of 130,250 ,m. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem: 3708,3719, 2004 [source] Recommending change clusters to support software investigation: an empirical studyJOURNAL OF SOFTWARE MAINTENANCE AND EVOLUTION: RESEARCH AND PRACTICE, Issue 3 2010Martin P. Robillard Abstract During software maintenance tasks, developers often spend a valuable amount of effort investigating source code. This effort can be reduced if tools are available to help developers navigate the source code effectively. We studied to what extent developers can benefit from information contained in clusters of change sets to guide their investigation of a software system. We defined change clusters as groups of change sets that have a certain amount of elements in common. Our analysis of 4200 change sets for seven different systems and covering a cumulative time span of over 17 years of development showed that less than one in five tasks overlapped with change clusters. Furthermore, a detailed qualitative analysis of the results revealed that only 13% of the clusters associated with applicable change tasks were likely to be useful. We conclude that change clusters can only support a minority of change tasks, and should only be recommended if it is possible to do so at minimal cost to the developers. Copyright © 2009 John Wiley & Sons, Ltd. [source] Corrosion of ZrB2 Powder During Wet Processing , Analysis and ControlJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 5 2008Sea-Hoon Lee Corrosion behavior of ZrB2 powder during wet processing in water or ethyl alcohol was studied both with and without an organic additive. Incorporation of oxygen and pH change did not intensively occur during static aging of aqueous slurries, but corrosion was enhanced when stirring the slurries. The oxygen content of the powder increased rather rapidly with milling time in ethyl alcohol. The molecular weight of polyethylenimine effected the pH change and oxygen content of ZrB2 powder, after corrosion in water for 18 months. X-ray photoelectron spectroscopy analysis informed that the surface of both the pristine and corroded powders was mainly covered with ZrOH, but a certain amount of Zr,B bonding remained at the powder surface after the wet processing. [source] Densification of the PLZT Films Derived from Polymer-Modified Solution by Tailoring Annealing ConditionsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 3 2007Z. H. Du The Pb0.91La0.09(Zr0.65,Ti0.35)0.9775O3 films were prepared from the solution containing polyvinylpyrrolidone, with Mw of 360 000. A fast heating rate of 40°C/min was used to heat our samples to temperatures in the range of 550°,750°C for different durations. Both a rapid heating rate and isothermal holding at a proper temperature are found to be essential for obtaining dense and crack-free PLZT films. The TG-DTA and Fourier-transform infrared results indicated that the fast heating rate could keep a certain amount of polyvinylpyrrolidone residues undecomposed to a higher temperature (<700°C), which was found to be beneficial for the densification of the films during subsequent isothermal hold. The possible mechanisms responsible for the enhanced densification have been discussed. In addition, the effects of annealing temperature on the electrical and optical properties were also investigated. [source] Transmission Electron Microscopy Microstructure of 0.95(Na0.5K0.5)NbO3,0.05BaTiO3 CeramicsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 11 2006Hwack Joo Lee Microstructural characterizations using transmission electron microscopy on 0.95(Na0.5K0.5)NbO3,0.05BaTiO3 ceramics sintered at 1030°,1150°C for 2 h were carried out. The liquid phase was found at the triple junction of the grains in all specimens and abnormal grain growth occurred in the presence of the liquid phase. Abnormally grown grains whose shapes were cuboidal were well developed. Anisotropically faceted amorphous liquid phase pockets were observed inside the grain in a specimen sintered at 1060°C for 2 h. The interface between the grain and the liquid matrix was flat and some were identified to be {100} planes of the grains. A certain amount of liquid at the sintering temperature of 1060°C enhanced the abnormal grain growth and contributed to the improvement of the piezoelectric properties. [source] Velocity dispersions of dwarf spheroidal galaxies: dark matter versus MONDMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2001Ewa L. We present predictions for the line-of-sight velocity dispersion profiles of dwarf spheroidal galaxies and compare them to observations in the case of the Fornax dwarf. The predictions are made in the framework of standard dynamical theory of spherical systems with different velocity distributions. The stars are assumed to be distributed according to Sérsic laws with parameters fitted to observations. We compare predictions obtained assuming the presence of dark matter haloes (with density profiles adopted from N -body simulations) with those resulting from Modified Newtonian Dynamics (MOND). If the anisotropy of velocity distribution is treated as a free parameter, observational data for Fornax are reproduced equally well by models with dark matter and with MOND. If stellar mass-to-light ratio of 1 M,/L, is assumed, the required mass of the dark halo is , two orders of magnitude larger than the mass in stars. The derived MOND acceleration scale is . In both cases a certain amount of tangential anisotropy in the velocity distribution is needed to reproduce the shape of the velocity dispersion profile in Fornax. [source] Language and nationality: the role of policy towards Celtic languages in the consolidation of Tudor powerNATIONS AND NATIONALISM, Issue 3 2001Gillian Brennan This article considers the attitude of the governing elite in sixteenth-century England to the minority languages spoken by subjects within their jurisdiction, concentrating on Cornish, Welsh and Irish. Perhaps influenced by the tendency of nineteenth-century nationalists to equate nationality and language, historians have assumed that Tudor governments were hostile to languages other than English and wished to suppress them. An examination of a variety of sources leads to the suggestion that this was not the case. There was a certain amount of apprehension in the political sphere in the 1530s but in the second half of the century cultural perception of languages dominated as attempts to spread the Protestant faith led to an encouragement of the range of vernaculars. The conclusion points to parallels between sixteenth-century and contemporary sympathy towards minority cultures in the context of the devolution debate. [source] Network disconnection problems in a centralized networkNAVAL RESEARCH LOGISTICS: AN INTERNATIONAL JOURNAL, Issue 7 2007Young-Soo Myung Abstract We consider three network disconnection problems in a centralized network where a source node provides service to the other nodes, called demand nodes. In network disconnection problems, each demand node gets a certain benefit when connected to a source node and a network attacker destroys edges to prevent demand nodes from achieving benefits. As destroying edges incurs expenses, an attacker considers the following three different strategies. The first is to maximize the sum of benefits of the disconnected nodes while keeping the total edge destruction cost no more than a given budget. The second is to minimize the total destruction cost needed to make a certain amount of benefits not accomplished. The last is to minimize the ratio of the total destruction cost to the benefits not accomplished. In this paper, we develop exact algorithms to solve the above three problems. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007 [source] Adjustment of leaf photosynthesis to shade in a natural canopy: rate parametersPLANT CELL & ENVIRONMENT, Issue 3 2005A. LAISK ABSTRACT The present study was performed to investigate the adjustment of the rate parameters of the light and dark reactions of photosynthesis to the natural growth light in leaves of an overstorey species, Betula pendula Roth, a subcanopy species, Tilia cordata P. Mill., and a herb, Solidago virgaurea L., growing in a natural plant community in Järvselja, Estonia. Shoots were collected from the site and individual leaves were measured in a laboratory applying a standardized routine of kinetic gas exchange, Chl fluorescence and 820 nm transmittance measurements. These measurements enabled the calculations of the quantum yield of photosynthesis and rate constants of excitation capture by photochemical and non-photochemical quenchers, rate constant for P700+ reduction via the cytochrome b6f complex with and without photosynthetic control, actual maximum and potential (uncoupled) electron transport rate, stomatal and mesophyll resistances for CO2 transport, Km(CO2) and Vm of ribulose-bisphosphate carboxylase-oxygenase (Rubisco) in vivo. In parallel, N, Chl and Rubisco contents were measured from the same leaves. No adjustment toward higher quantum yield in shade compared with sun leaves was observed, although relatively more N was partitioned to the light-harvesting machinery in shade leaves (H. Eichelmann et al., 2004). The electron transport rate through the Cyt b6f complex was strongly down-regulated under saturating light compared with darkness, and this was observed under atmospheric, as well as saturating CO2 concentration. In vivo Vm measurements of Rubisco were lower than corresponding reported measurements in vitro, and the kcat per reaction site varied widely between leaves and growth sites. The correlation between Rubisco Vm and the photosystem I density was stronger than between Vm and the density of Rubisco active sites. The results showed that the capacity of the photosynthetic machinery decreases in shade-adjusted leaves, but it still remains in excess of the actual photosynthetic rate. The photosynthetic control systems that are targeted to adjust the photosynthetic rate to meet the plant's needs and to balance the partial reactions of photosynthesis, down-regulate partial processes of photosynthesis: excess harvested light is quenched non-photochemically; excess electron transport capacity of Cyt b6f is down-regulated by ,pH-dependent photosynthetic control; Rubisco is synthesized in excess, and the number of activated Rubisco molecules is controlled by photosystem I-related processes. Consequently, the nitrogen contained in the components of the photosynthetic machinery is not used at full efficiency. The strong correlation between leaf nitrogen and photosynthetic performance is not due to the nitrogen requirements of the photosynthetic apparatus, but because a certain amount of energy must be captured through photosynthesis to maintain this nitrogen within a leaf. [source] Some safety aspects on the design of sparger systems for the oxidation of organic liquidsPROCESS SAFETY PROGRESS, Issue 4 2006Manfred Weber Abstract This article summarizes all important parameters for a proper and safe design of the sparger system for large bubble columns, used for the oxidation of organic liquids with air or oxygen enriched air. As an example, this is done for the oxidation of cumene (isopropylbenzene), which is worldwide used in phenol processes. Based on data in the literature and newly measured flammability limits at 100° C and 5 barg, the potential hazards from uncontrolled gas reactions can be avoided, ultimately avoiding an explosion in the sparger system. For normal operation, a minimum flow of gas is necessary to ensure a uniform flow through all outlets, which are typically holes with a diameter of several millimeters. All holes should be directed towards the vessel bottom to self-drain the sparger. For start-up, a previous inerting of the sparger with nitrogen is preferable. Nevertheless, a certain amount of organic liquid may still be in the sparger system prior to start up. Therefore, the compressed air/oxygen should have a temperature below the Oxidation Initiation Temperature to avoid any initiation of a liquid phase oxidation within the sparger. In addition, the pressure in the sparger system should be high enough to keep the gas phase concentration of the organic liquid below the Lower Flammability Limit. © 2006 American Institute of Chemical Engineers Process Saf Prog, 2006 [source] Optimal Control of Selling Channels for an Online Retailer with Cost-per-Click Payments and Seasonal ProductsPRODUCTION AND OPERATIONS MANAGEMENT, Issue 3 2007Frank Y. Chen The problem studied in this paper is a predigestion of the decision faced by online retailers (etailers) that advertise on publisher or comparison-shopping websites. An etailer may sell its product not only through its online and bricks-and-mortar stores, but also through the websites of one or more third parties (e.g., Yahoo.com). However, the etailer has to pay a certain amount to such third parties in an action-based payment scheme, such as a cost-per-click (CPC) scheme. Under the CPC scheme, payment is based solely on click-throughs, which means that the etailer pays only when a shopper clicks through to the product page of its website. Only a fraction of such clicks lead to actual sales. The extra cost that is associated with shoppers who first click through to the third-party websites makes them less attractive as customers than those who directly visit the etailer's online store. Moreover, the CPC rate for a prominent placement is normally set by competitive bidding, and thus varies over time. Therefore, the etailer needs to decide dynamically whether or not to list on a third-party website. The structural properties of the optimal policy are discussed, and numerical examples are given to show the revenue impact of dynamic listing control. [source] | ||||||||||||||||||||||||||||||||||