bluuebunny/crossref_metadata_2025 huggingface dataset:
Uniqueness of chemical equilibria in ideal mixtures of ideal gases
Authors: Powers Joseph M. , Paolucci Samuel
Published: November 2008

We prove the uniqueness of chemical equilibrium for an ideal mixture of ideal gases in a closed, spatially homogeneous volume. Uniqueness, a fundamental issue of chemical physics, is incompletely justified in textbooks and much of the scientific literature. We first reproduce a little known proof by Zel’dovich and show in a more direct fashion than originally presented that a unique equilibrium exists for isothermal reactions. Zel’dovich’s approach is then extended to the adiabatic case, and a more complete exposition than that of Aris is provided. The example of an isothermal, isochoric O-O2-O3 system provides an illustration of uniqueness. The discussion should be useful for students and instructors of graduate level thermal physics, as well as for researchers in macroscale reaction dynamics.
A tabletop experiment for the direct measurement of the speed of light
Authors: Aoki Kenichiro , Mitsui Takahisa
Published: November 2008

We describe a tabletop experiment for the direct measurement of the speed of light to an accuracy of a few percent. The experiment is accessible to students not majoring in science or engineering. The experiment can include a measurement of the index of refraction of a sample. We discuss the experimental apparatus and safety considerations. The results and limitations of the experiment are analyzed, based partly on our experience in employing the experiment in student laboratories.
Validity and reliability of the force and motion conceptual evaluation
Authors: Ramlo Susan
Published: November 2008

The assessment of learning has become a key component in program evaluation, grant proposals, and education research. Assessment requires valid and reliable instruments. The Force and Motion Conceptual Evaluation (FMCE) is one of several multiple-choice tests used to evaluate the learning of force and motion concepts. Although many physics education researchers accept its validity and reliability, validity and reliability estimates based on typical statistical analyses of data have not been established. This study used FMCE post-test results for approximately 150 students in a first-semester college physics course to estimate reliability and content validity. The results indicate that the FMCE is a valuable instrument for measuring student learning.
Novel optical properties of a submerged light bulb
Authors: James Mark C.
Published: November 2008

When an unlit frosted light bulb is immersed in water, the inside frosting appears to shrink, and the outside surface of the bulb appears to become reflective. We explore these interesting effects using geometric optics at the level of introductory physics. It is found that rays emitted from the particles of powder that coat the inside surface of a frosted bulb emerge in conical beams when the bulb is submerged, which results in a reduction of the apparent size of the bulb’s internal surface. The observed reflectivity is explained by the total internal reflection that occurs at the internal glass-gas interface. Light rays that refract through a clear bulb are analyzed to understand why a small spherical internal surface appears to exist in this case. The effects of bulb thickness, viewing height, and frustrated total internal reflection are also considered.
Opt-out plus, the patients’ choice: preferences of cancer patients concerning information and consent regimen for future research with biological samples archived in the context of treatment
Authors: Vermeulen E , Schmidt M K , Aaronson N K , Kuenen M , van der Valk P , Sietses C , van den Tol P , van Leeuwen F E
Published: November 2008

Aims:

The aims of this study were to determine: (1) which consent procedures patients prefer for future medical research with tissue stored following surgery; (2) the percentage of patients who choose not to provide consent for research with their stored tissue; (3) the reasons given for denying such tissue use.

Methods:

Patients (n = 103) from the Vrije Universiteit Medical Centre, an academic hospital in The Netherlands, who had recently undergone surgery for breast or colorectal cancer were mailed a questionnaire about preferences for consent regimens.

Results:

Seventy-six patients (74%) completed the questionnaire. Only two patients (3%) chose not to provide consent for research with their stored tissue. The majority of patients (60%) preferred an “opt-out plus” procedure that included receiving active, verbal information to “one-time general consent” (11%) or to an “opt-out” procedure without verbal notification (5%). Only 3% indicated a wish to be asked for consent for each new research project and 21% did not know what they preferred or had no preference. There were no significant associations observed between preference for the various consent regimens and age, sex, educational level or personal sense of ownership of the stored tissue.

Conclusion:

Patients prefer an opt-out plus procedure that includes the provision of explicit, verbal and written information. Less than 5% of patients decline to consent to the use of their stored tissue for research purposes.
Mobile phone base stations and adverse health effects: phase 1 of a population-based, cross-sectional study in Germany
Authors: Blettner M , Schlehofer B , Breckenkamp J , Kowall B , Schmiedel S , Reis U , Potthoff P , Schüz J , Berg-Beckhoff G
Published: November 2008

Objective:

The aim of this first phase of a cross-sectional study from Germany was to investigate whether proximity of residence to mobile phone base stations as well as risk perception is associated with health complaints.

Methods:

The researchers conducted a population-based, multi-phase, cross-sectional study within the context of a large panel survey regularly carried out by a private research institute in Germany. In the initial phase, reported on in this paper, 30 047 persons from a total of 51 444 who took part in the nationwide survey also answered questions on how mobile phone base stations affected their health. A list of 38 health complaints was used. A multiple linear regression model was used to identify predictors of health complaints including proximity of residence to mobile phone base stations and risk perception.

Results:

Of the 30 047 participants (response rate 58.6%), 18.7% of participants were concerned about adverse health effects of mobile phone base stations, while an additional 10.3% attributed their personal adverse health effects to the exposure from them. Participants who were concerned about or attributed adverse health effects to mobile phone base stations and those living in the vicinity of a mobile phone base station (500 m) reported slightly more health complaints than others.

Conclusions:

A substantial proportion of the German population is concerned about adverse health effects caused by exposure from mobile phone base stations. The observed slightly higher prevalence of health complaints near base stations can not however be fully explained by attributions or concerns.
Specific antibodies to diisocyanate and work-related respiratory symptoms in apprentice car-painters
Authors: Dragos M , Jones M , Malo J-L , Ghezzo H , Gautrin D
Published: November 2008

Background:

Isocyanates are the main cause of occupational asthma in most countries. Study of immunological markers of diisocyanate asthma may identify individuals at risk.

Objectives:

(1) To study changes in specific antibodies to hexamethylene diisocyanates (HDI); (2) to describe the incidence of work-related respiratory symptoms in relation to changes in specific antibody levels.

Methods:

Prospective study in 385 apprentice car-painters during their 18 months of training. Participants were assessed on entering and completing their training using questionnaires, methacholine challenges and measurements of HDI-specific immunoglobulin E (IgE), immunoglobulin G (IgG) and subclass 4 of IgG (IgG4) antibodies.

Results:

Complete data are available for 298 subjects. 13 subjects (4.4%) reported ⩾1 new work-related lower respiratory symptoms and 19 (6.4%), ⩾1 new work-related nasal symptoms. Increases in levels of specific IgE and IgG above the 97th and 95th percentiles were significantly associated with duration of exposure. Increase in specific IgG was inversely related to incidence of work-related lower respiratory symptoms (OR = 0.001, 95% CI 0.000 to 0.09) after adjusting for relevant covariates. The rise in specific IgG4 was significantly greater in those who did not develop work-related nasal symptoms (OR = 0.09, 95% CI 0.01 to 0.7).

Conclusion:

In this cohort of apprentice car-painters, a small proportion show increases in HDI-specific IgG and IgE after few months of exposure. Increases in specific IgG and IgG4 appear to have a protective effect on the incidence of work-related lower and upper respiratory symptoms, respectively. Assessment of specific antibodies to isocyanates may help identify subjects at risk of developing symptoms.
Hepatitis E,Helicobacter pyloriand peptic ulcers in workers exposed to sewage: a prospective cohort study
Authors: Tschopp A , Joller H , Jeggli S , Widmeier S , Steffen R , Hilfiker S , Hotz P
Published: November 2008

Background:

Workers exposed to sewage may have an increased risk of infection byHelicobacter pyloriand hepatitis E virus (HEV).

Objectives:

To assess the incidence of clinical hepatitis E and peptic ulcers and the seroconversion rate of antibodies toH pyloriand HEV in workers with and without sewage exposure.

Methods:

332 workers exposed to sewage and a control group of 446 municipal manual workers (61% participation rate) entered a prospective cohort study with clinical examination and determination of antibodies toH pyloriand HEV (immunoglobulins G and A or G and M, respectively). Survival curves were examined with log rank tests and Cox regressions. Travelling to endemic areas, socioeconomic level, age, country of childhood, number of siblings, and personal protective equipment were considered as the main confounding factors.

Results:

Incidence of clinical hepatitis E was not increased in sewage workers. One peptic ulcer and three eradications were recorded in sewage workers compared with no peptic ulcers and 12 eradications in control workers. Incidence rates of approximately 0.01, 0.10, and 0.15 seroconversion/person-year for hepatitis E,H pyloriIgG andH pyloriIgA, respectively, were found in both exposed and non-exposed workers. Survival curves did not show an increased risk in sewage workers and no association with any exposure indicator was found. Sensitivity analyses did not alter these results.

Conclusions:

Sewage does not appear to be a source of occupational infection byH pylorior HEV in trained sewage workers with personal protective equipment working in a region with good sanitation.
Air pollution and asthma severity in adults
Authors: Rage E , Siroux V , Künzli N , Pin I , Kauffmann F ,   on behalf of the Epidemiological Study on the Genetics and Environment of Asthma
Published: November 2008

Background/objectives:

There is evidence that exposure to air pollution affects asthma, but the effect of air pollution on asthma severity has not been addressed. The aim was to assess the relation between asthma severity during the past 12 months and home outdoor concentrations of air pollution.

Methods:

Asthma severity over the past 12 months was assessed in two complementary ways among 328 adult asthmatics from the French Epidemiological study on the Genetics and Environment of Asthma (EGEA) examined between 1991 and 1995. The four-class severity score integrated clinical events and type of treatment. The five-level asthma score is based only on the occurrence of symptoms. Nitrogen dioxide (NO2), sulphur dioxide (SO2) and ozone (O3) concentrations were assigned to each residence using two different methods. The first was based on the closest monitor data from 1991 to 1995. The second consisted of spatial models that used geostatistical interpolations and then assigned air pollutants to the geo-coded residences (1998).

Results:

Higher asthma severity score was significantly related to the 8-hour average of ozone during April-September (O3-8 h) and the number of days (O3-days) with 8-hour ozone averages above 110 μg.m−3(for a 36-day increase, equivalent to the interquartile range, in O3-days, odds ratio 2.22 (95% confidence interval 1.61 to 3.07) for one class difference in score). Adjustment for age, sex, smoking habits, occupational exposure, and educational level did not alter results. Asthma severity was unrelated to NO2. Both exposure assessment methods and severity scores resulted in very similar findings. SO2correlated with severity but reached statistical significance only for the model-based assignment of exposure.

Conclusions:

The observed associations between asthma severity and air pollution, in particular O3, support the hypothesis that air pollution at levels far below current standards increases asthma severity.
Occupational burnout as a predictor of disability pension: a population-based cohort study
Authors: Ahola K , Gould R , Virtanen M , Honkonen T , Aromaa A , Lönnqvist J
Published: November 2008

Objectives:

The aim of this study was to investigate whether burnout predicts new disability pension at population level during a follow-up of approximately 4 years. The diagnosis for which the disability pension was granted was also examined in relation to the level of burnout.

Methods:

We used a population-based cohort sample (n = 3125) of 30–60-year-old employees from an epidemiological health study, the Health 2000 Study, gathered during 2000–2001 in Finland. The data collection comprised an interview, a clinical health examination including a standardised mental health interview, and a questionnaire including the Maslach Burnout Inventory-General Survey. Disability pensions and their causes until December 2004 were extracted from national pension records. The association between burnout and new disability pension was analysed with logistic regression models adjusted for sociodemographic factors and health at baseline.

Results:

Altogether 113 persons were granted a new disability pension during the follow-up: 22% of those with severe burnout, 6% of those with mild burnout, and 2% of those with no burnout at baseline. After sociodemographic factors and health were adjusted for, each one-point increase in the overall burnout sum score was related to 49% increase in the odds for a future disability pension. A disability pension was most often granted on the basis of mental and behavioural disorders and diseases of the musculoskeletal system among those with burnout. After adjustments, exhaustion dimension among men and cynicism dimension among a combined group of men and women predicted new disability pensions.

Conclusion:

Burnout predicts permanent work disability and could therefore be used as a risk marker of chronic health-related work stress. To prevent early exit from work life, working conditions and employee burnout should be regularly assessed with the help of occupational health services.
Asbestosis mortality in the USA: facts and predictions
Authors: dos Santos Antao V C , Pinheiro G A , Wassell J T
Published: November 2008

Background:

Mortality trends in the USA show that deaths from asbestosis are increasing, while deaths related to other pneumoconiosis are declining.

Objectives:

To analyse the association between asbestos consumption and asbestosis mortality trends.

Methods:

In an epidemiological time series study, we used a modern computer-intensive local regression method to evaluate the relationship between asbestos consumption per capita (1900–2006) as the predictor variable and number of deaths from asbestosis (1968–2004). The predictor variable was progressively lagged by annual increments from 30 to 60 years and the goodness of fit assessed for each lag period. The model having the smallest Akaike’s Information Criteria was used to derive extrapolated estimates of future mortality based on more recent asbestos consumption data.

Results:

Asbestos consumption per capita reached a peak in 1951 and gradually declined until 1973, when it started to drop rapidly. In 2006, it was 0.0075 kg/person/year. There were 25 564 deaths from asbestosis over the period 1968–2004. The best-fitting model (adjusted coefficient of determination (R2) = 99.7%) for 1968–2004 deaths from asbestosis used asbestos consumption per capita 48 years prior (1920–1956) and the log value of asbestos consumption per capita 43 years prior (1925–1961). This model predicts a total of 29 667 deaths (95% CI 19 629 to 39 705) to occur during 2005–2027 (an average of 1290 deaths per year).

Conclusions:

This study demonstrates a clear association between asbestos consumption and deaths from asbestosis and indicates that asbestosis deaths are not expected to decrease sharply in the next 10–15 years.
Fifty-year follow-up of mortality among a cohort of iron-ore miners in Sweden, with specific reference to myocardial infarction mortality
Authors: Björ B , Burström L , Jonsson H , Nathanaelsson L , Damber L , Nilsson T
Published: November 2008

Objectives:

This study investigates both general mortality and mortality from myocardial infarction among men employed in iron-ore mines in Sweden.

Methods:

The mortality of employees (surface and underground workers) at the iron-ore mines in Malmberget and Kiruna, Sweden was investigated. The study cohort comprised men who had been employed for at least 1 year between 1923 and 1996. The causes of death were obtained from the national cause of death register from 1952 to 2001. Indirect standardised mortality ratios (SMR) were calculated for four main causes. Mortality specifically from myocardial infarction was also analysed.

Results:

4504 deaths in the cohort gave an SMR for total mortality of 1.05 (95% CI 1.02 to 1.09). Mortality was significantly higher for lung cancer (SMR 1.73, 95% CI 1.52 to 1.97). There was an increased risk of injuries and poisonings (SMR 1.34, 95% CI 1.24 to 1.46) and respiratory diseases (SMR 1.14, 95% CI 1.00 to 1.28). There were 1477 cases of myocardial infarction, resulting in an SMR of 1.12 (95% CI 1.07 to 1.18). SMR was higher (1.35, 95% CI 1.22 to 1.50) for men aged ⩽60 years than for those >60 years of age (1.06, 95% CI 1.00 to 1.13).

Conclusions:

Mortality from myocardial infarction was higher than expected. There was also an increased risk of death from injuries and poisonings, lung cancer and respiratory diseases, as well as higher general mortality. Our findings support the results of previous studies that there is an association between working in the mining industry and adverse health outcomes.
The relationship of respiratory and cardiovascular hospital admissions to the southern California wildfires of 2003
Authors: Delfino R J , Brummel S , Wu J , Stern H , Ostro B , Lipsett M , Winer A , Street D H , Zhang L , Tjoa T , Gillen D L
Published: November 2008

Objective:

There is limited information on the public health impact of wildfires. The relationship of cardiorespiratory hospital admissions (n = 40 856) to wildfire-related particulate matter (PM2.5) during catastrophic wildfires in southern California in October 2003 was evaluated.

Methods:

Zip code level PM2.5concentrations were estimated using spatial interpolations from measured PM2.5, light extinction, meteorological conditions, and smoke information from MODIS satellite images at 250 m resolution. Generalised estimating equations for Poisson data were used to assess the relationship between daily admissions and PM2.5, adjusted for weather, fungal spores (associated with asthma), weekend, zip code-level population and sociodemographics.

Results:

Associations of 2-day average PM2.5with respiratory admissions were stronger during than before or after the fires. Average increases of 70 μg/m3PM2.5during heavy smoke conditions compared with PM2.5in the pre-wildfire period were associated with 34% increases in asthma admissions. The strongest wildfire-related PM2.5associations were for people ages 65–99 years (10.1% increase per 10 μg/m3PM2.5, 95% CI 3.0% to 17.8%) and ages 0–4 years (8.3%, 95% CI 2.2% to 14.9%) followed by ages 20–64 years (4.1%, 95% CI −0.5% to 9.0%). There were no PM2.5–asthma associations in children ages 5–18 years, although their admission rates significantly increased after the fires. Per 10 μg/m3wildfire-related PM2.5, acute bronchitis admissions across all ages increased by 9.6% (95% CI 1.8% to 17.9%), chronic obstructive pulmonary disease admissions for ages 20–64 years by 6.9% (95% CI 0.9% to 13.1%), and pneumonia admissions for ages 5–18 years by 6.4% (95% CI −1.0% to 14.2%). Acute bronchitis and pneumonia admissions also increased after the fires. There was limited evidence of a small impact of wildfire-related PM2.5on cardiovascular admissions.

Conclusions:

Wildfire-related PM2.5led to increased respiratory hospital admissions, especially asthma, suggesting that better preventive measures are required to reduce morbidity among vulnerable populations.
Urinary naphthalene and phenanthrene as biomarkers of occupational exposure to polycyclic aromatic hydrocarbons
Authors: Sobus J R , Waidyanatha S , McClean M D , Herrick R F , Smith T J , Garshick E , Laden F , Hart J E , Zheng Y , Rappaport S M
Published: November 2008

Objectives:

The study investigated the utility of unmetabolised naphthalene (Nap) and phenanthrene (Phe) in urine as surrogates for exposures to mixtures of polycyclic aromatic hydrocarbons (PAHs).

Methods:

The report included workers exposed to diesel exhausts (low PAH exposure level, n = 39) as well as those exposed to emissions from asphalt (medium PAH exposure level, n = 26) and coke ovens (high PAH exposure level, n = 28). Levels of Nap and Phe were measured in urine from each subject using head space-solid phase microextraction and gas chromatography-mass spectrometry. Published levels of airborne Nap, Phe and other PAHs in the coke-producing and aluminium industries were also investigated.

Results:

In post-shift urine, the highest estimated geometric mean concentrations of Nap and Phe were observed in coke-oven workers (Nap: 2490 ng/l; Phe: 975 ng/l), followed by asphalt workers (Nap: 71.5 ng/l; Phe: 54.3 ng/l), and by diesel-exposed workers (Nap: 17.7 ng/l; Phe: 3.60 ng/l). After subtracting logged background levels of Nap and Phe from the logged post-shift levels of these PAHs in urine, the resulting values (referred to as ln(adjNap) and ln(adjPhe), respectively) were significantly correlated in each group of workers (0.71⩽ Pearson r⩽0.89), suggesting a common exposure source in each case. Surprisingly, multiple linear regression analysis of ln(adjNap) on ln(adjPhe) showed no significant effect of the source of exposure (coke ovens, asphalt and diesel exhaust) and further suggested that the ratio of urinary Nap/Phe (in natural scale) decreased with increasing exposure levels. These results were corroborated with published data for airborne Nap and Phe in the coke-producing and aluminium industries. The published air measurements also indicated that Nap and Phe levels were proportional to the levels of all combined PAHs in those industries.

Conclusion:

Levels of Nap and Phe in urine reflect airborne exposures to these compounds and are promising surrogates for occupational exposures to PAH mixtures.
Compensation patterns for healthcare workers in British Columbia, Canada
Authors: Alamgir H , Siow S , Yu S , Ngan K , Guzman J
Published: November 2008

Objectives:

This report examines relationships between the acceptance of compensation claims, and employee and workplace characteristics for healthcare workers in British Columbia, Canada to determine suitability of using only accepted claims for occupational epidemiology research.

Methods:

A retrospective cohort of full-time healthcare workers was constructed from an active incident surveillance database. Incidents filed for compensation over a 1-year period were examined for initial claim decision within a 6-month window relative to sub-sector of employment, age, sex, seniority, occupation of workers, and injury category. Compensation costs and duration of time lost for initially accepted claims were also investigated. Multiple logistic regression models with generalised estimating equations (GEEs) were used to calculate adjusted relative odds (ARO) of claims decision accounting for confounding factors and clustering effects.

Results:

Employees of three health regions in British Columbia filed 2274 work-related claims in a year, of which 1863 (82%) were initially accepted for compensation. Proportion of claims accepted was lowest in community care (79%) and corporate office settings (79%) and highest in long-term care settings (86%). Overall, 46% of claims resulting fromallergy/irritationwere accepted, in contrast to 98% acceptance of claims fromcutsandpuncture wounds. Licensed practical nurses had the lowest odds of claims not accepted compared with registered nurses (ARO (95% CI)  =  0.55 (0.33 to 0.91)), whereas management/administrative staff had the highest odds (ARO  =  2.91 (1.25 to 6.79)) of claims not accepted. A trend was observed with higher seniority of workers associated with lower odds of non-acceptance of claims.

Conclusions:

Analysis from British Columbia’s healthcare sector suggests variation in workers’ compensation acceptance exists across sub-sectors, occupations, seniority of workers, and injury categories. The patterns observed, however, were independent of age and sex of workers. Results suggest that when using workers’ compensation datasets, local adjudication regulations and factors associated with acceptance of claims should be taken into consideration.
Correlation between co-exposures to noise and air pollution from traffic sources
Authors: Davies H W , Vlaanderen J J , Henderson S B , Brauer M
Published: November 2008

Background:

Both air and noise pollution associated with motor vehicle traffic have been associated with cardiovascular disease. Similarities in pollution source and health outcome mean that there is potential for noise to confound studies of air pollution and cardiovascular disease, and vice versa, or for more complex interactions to occur.

Methods:

The correlations between 2-week average roadside concentrations of nitrogen dioxide (NO2) and nitrogen oxides (NOX) and short term average noise levels (Leq,5min) for 103 urban sites with varying traffic, environment and infrastructure characteristics were examined.

Results:

The Pearson correlation coefficient for Leq,5minand NO2was 0.53, and for Leq,5minand NOX, 0.64. Factors influencing the degree of correlation were number of lanes on the closest road, number of cars or trucks during noise sampling and presence of a major intersection.

Conclusions:

We recommend measurement of both pollutants in future studies of traffic-related pollution and cardiovascular disease to allow for more sophisticated analysis of this relationship.
X-ray and high-resolution 1H and 13C NMR of smooth muscle relaxant sesquiterpene lactones
Authors: Calsteren Marie-Rose Van , Jankowski Christopher K , Reyes-Chilpa Ricardo , Jiménez-Estrada Manuel , Campos Maria G , Zarazua-Lozada Abraham , Oropeza Martha , Lesage Denis
Published: November 2008

The structure and stereochemistry of four sesquiterpene lactones, budlein A (1), zaluzanin A (2), and glaucolides D (3a) and E (3b), isolated from Mexican Asteraceae species, for which only partial NMR data could be found in the literature, were determined. A combination of 1D and 2D high-resolution NMR experiments, such as DEPT, COSY, NOESY, ROESY, HMQC, HSQC, and HMBC, were used to completely assign the 1H and 13C spectra. The crystal structures of zaluzanin A (2) and glaucolide E (3b) were also determined. Glaucolides D and E have been previously reported to relax KCl-induced contraction in rat uterine smooth muscle; therefore, the effects of zaluzanin A and budlein A were examined in the same model. It was found that both compounds can relax contraction induced by KCl, but only zaluzanin A induced relaxation when contraction was induced with oxytocin. The preliminary biological test results according to these profiles are reported in this paper.Key words: NMR data, X-ray data, sesquiterpene lactones, Mexican Asteraceae, smooth muscle relaxant.
FIRST-PRINCIPLES STUDY OF THE EFFECTS OF GOLD ADSORPTION ON THE Al(001) SURFACE PROPERTIES
Authors: DEHNAVI N. ZARE , PAYAMI M.
Published: November 2008

In this paper, we have studied theoretically the effects of gold adsorption on the Al (001) surface, using ab initio pseudo-potential method in the framework of the density functional theory. Having found the hollow sites at the Al (001) surface as the most preferred adsorption sites, we have investigated the effects of the Au adsorption with different coverages (Θ =0.11, 0.25, 0.50, 0.75, 1.00 ML) on the geometry, adsorption energy, surface dipole moment, and the work function of the Al (001) surface. The results show that even though the work function of the Au substrate increases with the Au coverage, the surface dipole moment decreases with the changes in coverage from Θ =0.11 to 0.25 ML. We have explained this behavior by analyzing the electronic and ionic charge distributions. Furthermore, by studying the diffusion of Au atoms into the substrate, we have shown that at room temperature the diffusion rate of Au atoms into the substrate is negligible but increasing the temperature to about 200°C the Au atoms significantly diffuse into the substrate, in agreement with the experiment.
AN INTEGRATED DP-MIP MODEL FOR OPTIMAL CROP MIX SELECTION WITH DEFICIT IRRIGATION
Authors: AZAIEZ M. N.
Published: November 2008

We consider a region suffering from irrigation water scarcity. Candidate crops differ widely in their growth cycles, economic values and water consumption. We develop an integrated dynamic programming-mixed integer programming model to solve for optimal land exploitation over a one year horizon for multiple crops. The model applies deficit irrigation in order to increase the irrigated area at the expense of reducing crop yield per unit area. The dynamic program (DP) guarantees that deficit irrigation is only considered when it is economically efficient. Moreover, it provides optimal combinations of irrigation levels for each growth stage of candidate crops, accounting for the varying impact of water stress over time and the seasonal supply of irrigation water. The output of the DP serves as input to the mixed integer program (MIP). The MIP selects the most profitable crops in the right sequence to benefit the most from the crop-yield dependence on crop predecessor and allocates water and land optimally to maximize total profit. The objective function accounts for the attitude of the decision-maker toward risk by incorporating in its expression a risk-aversion coefficient.
MULTI-OBJECTIVE OPTIMIZATION IN RELIABILITY SYSTEM USING GENETIC ALGORITHM AND NEURAL NETWORK
Authors: CHEN LIANG-HSUAN , CHIANG CHENG-HSIUNG
Published: November 2008

To optimize the design of reliability systems, an analyst is frequently faced with the demand of achieving several targets (i.e., maximization of system reliability, minimizations of cost, volume, and weight), some of which may be in conflict with each other. This paper presents a novel hybrid approach, combining a multi-objective genetic algorithm and a neural network, for multi-objective optimization of a reliability system, namely GANNRS (Genetic Algorithm and Neural Network for Reliability System optimization). The multi-objective genetic algorithm's evolutionary strategy is based on the modified neighborhood design, and is presented to find the Pareto optimal solutions so as to provide a variety of compromise solutions to the decision makers. The purpose of the neural network is to generate a good initial population in order to speed up the searching by genetic algorithm. For demonstrating the feasibility of the proposed approach, four multi-objective optimization problems of reliability system are used, and the outcomes are compared with those from other methods. The evidence shows that the proposed GANNRS is more efficient in computation, and the results from the objectives are appealing.
AN ECONOMIC PRODUCTION LOT SIZE FOR CONTINUOUS DECREASE IN UNIT PRODUCTION COST
Authors: OUYANG B. C. , RAU H.
Published: November 2008

It is common that prices of raw materials, parts or products decrease significantly after they come onto the market. High technology products are good examples, such as PCs, CPUs, DRAM, and mobile phones. Consequently, the traditional economic production quantity (EPQ) model assuming a constant unit production cost is no longer suitable for today's time-based competition. This study incorporates linearly and exponentially decreasing unit production costs during the mature stage of a product life cycle and presents a mathematical inventory model for production policy. A recursive algorithm is developed to obtain the optimal production schedule and a one-dimension search method is applied to find the optimal number of production cycles. In addition, numerical examples to illustrate the proposed model and its significance with or without considering a continuous reduction in unit production costs for the production policy are discussed as well.
MULTI-CHANNEL FUZZY QUEUING SYSTEMS AND MEMBERSHIP FUNCTIONS OF RELATED FUZZY SERVICES AND FUZZY INTER-ARRIVAL TIMES
Authors: AYDIN ÖZLEM , APAYDIN AYŞEN
Published: November 2008

Queuing models need well defined knowledge on arrivals and service times. However, in real applications, because of some measurement errors or some loss of information, it is hard to achieve deterministic knowledge. Non-deterministic knowledge interferes or complicates analysis of the queuing model. Additionally, when the customers are asked about their impressions on waiting times or service times, mostly the answers are linguistic expressions like "I waited too much", "service was fast", and that the responses are. Linguistic statements and ill defined data make the sense of imprecision in the model. In this study, arrivals and service times are defined as fuzzy numbers in order to represent this imprecision. Fuzzy multi-channel queuing systems and membership functions are introduced in defining the arrivals and service times. Besides, a new membership function based on a probability function is studied. Fuzzy queuing characteristics are calculated via different membership functions and the results are compared on simulations. Among models it is found that, Generalized Beta Distribution membership function is the one that minimized the queuing characteristics.
BOSE–FERMI EQUIVALENCE IN THREE-DIMENSIONAL NONCOMMUTATIVE SPACETIME
Authors: AJITH K. M. , HARIKUMAR E. , SIVAKUMAR M.
Published: November 2008

We study the fermionisation of Seiberg–Witten mapped action (to order θ) of the λϕ4 theory coupled minimally with U(1) gauge field governed by Chern–Simons action. Starting from the corresponding partition function we derive nonperturbatively (in coupling constant) the partition function of the spin-1/2 theory following Polyakov spin factor formalism. We find that the dual interacting fermionic theory is nonlocal. This feature also persists in the limit of vanishing self-coupling. In θ → 0 limit, the commutative result is obtained.
CONSTRAINTS ON NONCOMMUTATIVE HALL EFFECT REVISITED
Authors: GODINHO CRESUS F. L.
Published: November 2008

We consider a semiclassical formulation of the quantum Hall effect by means of an Chern–Simons gauge theory constructed for a Schrödinger field. We build up constraints managing the Faddeev–Jackiw algorithm and show a direct relation of the constraints with Hall conductivity. In the second step, we consider the noncommutative extension to the action computing the new and more general constraints and, as a right consequence, an interesting correction for the conductivity expression is found. Finally, we speculate possible interpretations of this new result and its consequences.
CHIRAL TENSOR FIELDS AND SPONTANEOUS BREAKING OF LORENTZ SYMMETRY
Authors: SCHWINDT JAN-MARKUS , WETTERICH CHRISTOF
Published: November 2008

Antisymmetric tensor fields interacting with quarks and leptons have been proposed as a possible solution to the gauge hierarchy problem. We compute the one-loop beta function for a quartic self-interaction of the chiral antisymmetric tensor fields. Fluctuations of the top quark drive the corresponding running coupling to a negative value as the renormalization scale is lowered. This may indicate a nonvanishing expectation value of the tensor field, and thus a spontaneous breaking of Lorentz invariance. Settling this issue will need the inclusion of tensor loops.
ABELIAN MAGNETIC MONOPOLES AND TOPOLOGICALLY MASSIVE VECTOR BOSONS IN SCALAR-TENSOR GRAVITY WITH TORSION POTENTIAL
Authors: ALI S. A. , CAFARO C. , CAPOZZIELLO S. , CORDA CH.
Published: November 2008

A Lagrangian formulation describing the electromagnetic interaction — mediated by topologically massive vector bosons — between charged, spin-½ fermions with an Abelian magnetic monopole in a curved space–time with nonminimal coupling and torsion potential is presented. The covariant field equations are obtained. The issue of coexistence of massive photons and magnetic monopoles is addressed in the present framework. It is found that despite the topological nature of photon mass generation in curved space–time with isotropic dilaton field, the classical field theory describing the nonrelativistic electromagnetic interaction between a point-like electric charge and magnetic monopole is inconsistent.
THE HARDNESS SPECTRUM OF QUARK- AND GLUON-JETS PRODUCED BY DIFFERENT FLAVOR QUARKS
Authors: TIAN FENG-GE , CHEN GANG , WEI HUI-LING
Published: November 2008

The hardness properties of quark- and gluon-jets produced by different flavor quarks are compared in 3-jet events of e+e- collision generated with Monte Carlo Simulation Jetset 7.4 generator at [Formula: see text]. The 3-jet events are obtained using the Durham algorithm and the quark- and gluon-jets are identified by angular-method. The average values of transverse momentum 〈pt〉, multiplicity 〈N〉 and rapidity 〈y〉 versus hardness for quark- and gluon-jets of different flavors are compared. It turns out that the distributions of 〈pt〉, 〈N〉 and 〈y〉 versus hardness of quark-jets are different to their flavors, while those of the gluon-jets are insensitive to the flavors. On the other hand, the 〈pt〉 and 〈N〉 of quark- and gluon-jets are strong positive correlated with hardness, but the 〈y〉 of those are negatively correlated with hardness.
DYNAMICAL PROPERTIES OF MULTI-WALLED CARBON NANOTUBES BASED ON A NONLOCAL ELASTICITY MODEL
Authors: YAN Y. , ZHANG L. X. , WANG W. Q. , HE X. Q. , WANG C. M.
Published: November 2008

This paper investigates the free vibration of multi-walled carbon nanotubes (MWCNTs) with simply supported ends. Based on the nonlocal elasticity theory which allows the effects of small length scale and the more refined van der Waals (vdW) interaction formulas, the equation of motion is first derived and then solved analytically. The results reveal that the effects of the small length scale are significant for small aspect ratios and high radial vibration modes, and are instead insensitive to the number of layers of MWCNTs and weakly dependent on the wall thickness of MWNTs. This finding means that the effects of small length scale on complicated MWCNTs may be simplified to double-walled carbon nanotubes (DWCNTs) or even single-walled carbon nanotubes (SWCNTs).
MAGNETIZATION OF BERYLLIUM MONOXIDE (BeO) WITHOUT MAGNETIC IMPURITIES: A FIRST-PRINCIPLES STUDY
Authors: SHEIN I. R. , GORBUNIVA M. A. , MAKURIN YU. N. , KIIKO V. S. , IVANOVSKII A. L.
Published: November 2008

Using the ab initio VASP-PAW method with the generalized gradient approximation, the magnetic behavior of wurtzite-like beryllium oxide ( BeO ) without magnetic impurities has been predicted. Our results indicate the transformation of non-magnetic insulator BeO into magnetic half-metal at the substitution of oxygen atoms by carbon or in the presence of beryllium vacancy.
ANOMALOUS INTERACTIONS AND EXACT Tc IN SUPERCONDUCTIVITY
Authors: MATTIS DANIEL C.
Published: November 2008

This theoretical study of superconductivity examines repulsive forces that, surprisingly, favor the BCS paired state. The value of Tc and the pairing symmetry (s-, p-, d-wave) are obtained exactly as eigenvalues in a given sector of a Fredholm integral equation of the second kind.
COLLABORATIVE WEB SEARCH BASED ON USER INTEREST SIMILARITY
Authors: GODOY DANIELA , AMANDI ANALÍA
Published: November 2008

The motivation behind personal information agents resides in the enormous amount of information available on the Web, which has created a pressing need for effective personalized techniques. In order to assists Web search these agents rely on user profiles modeling information preferences, interests and habits that help to contextualize user queries. In communities of people with similar interests, collaboration among agents fosters knowledge sharing and, consequently, potentially improves the results of individual agents by taking advantage of the knowledge acquired by other agents. In this paper, we propose an agent-based recommender system for supporting collaborative Web search in groups of users with partial similarity of interests. Empirical evaluation showed that the interaction among personal agents increases the performance of the overall recommender system, demonstrating the potential of the approach to reduce the burden of finding information on the Web.
COHOMOLOGY OF FROBENIUS ALGEBRAS AND THE YANG-BAXTER EQUATION
Authors: CARTER J. SCOTT , CRANS ALISSA S. , ELHAMDADI MOHAMED , KARADAYI ENVER , SAITO MASAHICO
Published: November 2008

A cohomology theory for multiplications and comultiplications of Frobenius algebras is developed in low dimensions, in analogy with Hochschild cohomology of bialgebras, based on deformation theory. Concrete computations are provided for key examples. Skein theoretic constructions give rise to solutions to the Yang-Baxter equation, using multiplications and comultiplications of Frobenius algebras, and 2-cocycles are used to obtain deformations of R-matrices thus obtained.
3-DIMENSIONAL SCHLÄFLI FORMULA AND ITS GENERALIZATION
Authors: LUO FENG
Published: November 2008

Several identities similar to the Schläfli formula are established for tetrahedra in a space of constant curvature.
RIGIDITY AND MODULARITY OF VERTEX TENSOR CATEGORIES
Authors: HUANG YI-ZHI
Published: November 2008

Let V be a simple vertex operator algebra satisfying the following conditions: (i) V(n)= 0 for n < 0, V(0)= ℂ1 and V′ is isomorphic to V as a V-module. (ii) Every ℕ-gradable weak V-module is completely reducible. (iii) V is C2-cofinite. (In the presence of Condition (i), Conditions (ii) and (iii) are equivalent to a single condition, namely, that every weak V-module is completely reducible.) Using the results obtained by the author in the formulation and proof of the general version of the Verlinde conjecture and in the proof of the Verlinde formula, we prove that the braided tensor category structure on the category of V-modules is rigid, balanced and nondegenerate. In particular, the category of V-modules has a natural structure of modular tensor category. We also prove that the tensor-categorical dimension of an irreducible V-module is the reciprocal of a suitable matrix element of the fusing isomorphism under a suitable basis.
QUANTUM TEICHMÜLLER THEORY AND REPRESENTATIONS OF THE PURE BRAID GROUP
Authors: BONAHON FRANCIS
Published: November 2008

We adapt some of the methods of quantum Teichmüller theory to construct a family of representations of the pure braid group of the sphere.
ON MUTATION AND KHOVANOV HOMOLOGY
Authors: CHAMPANERKAR ABHIJIT , KOFMAN ILYA
Published: November 2008

It is conjectured that the Khovanov homology of a knot is invariant under mutation. In this paper, we review the spanning tree complex for Khovanov homology, and reformulate this conjecture using a matroid obtained from the Tait graph (checkerboard graph) G of a knot diagram K. The spanning trees of G provide a filtration and a spectral sequence that converges to the reduced Khovanov homology of K. We show that the E2-term of this spectral sequence is a matroid invariant and hence invariant under mutation.
ON THE GENERALIZED VOLUME CONJECTURE AND REGULATOR
Authors: LI WEIPING , WANG QINGXUE
Published: November 2008

In this paper, by using the regulator map of Beilinson-Deligne on a curve, we show that the quantization condition posed by Gukov is true for the SL2(ℂ) character variety of the hyperbolic knot in S3. Furthermore, we prove that the corresponding ℂ*-valued closed 1-form is a secondary characteristic class (Chern-Simons) arising from the vanishing first Chern class of the flat line bundle over the smooth part of the character variety, where the flat line bundle is the pullback of the universal Heisenberg line bundle over ℂ* × ℂ*. Based on this result, we give a reformulation of Gukov's generalized volume conjecture from a motivic perspective.
FUNDAMENTAL GROUPS OF POSITIVELY CURVED n-MANIFOLDS WITH SYMMETRY RANK $> \frac{n}{6}$
Authors: RONG XIAOCHUN , WANG YUSHENG
Published: November 2008

In this paper, we obtain a classification for the fundamental groups of positively curved n-manifolds which admit isometric torus Tk-actions with [Formula: see text] and n ≥ 25.
IDENTIFICATION OF NAMES AND ACTIONS OF PRINCIPAL OBJECTS IN TV PROGRAM SEGMENTS USING CLOSED CAPTIONS
Authors: MIURA KIKUKA , YAMADA ICHIRO , SUMIYOSHI HIDEKI , YAGI NOBUYUKI
Published: November 2008

This paper proposes a method for automatically extracting principal video objects that appear in TV program segments and their actions using linguistic analysis of closed captions. We focus on features based on the text style of the closed captions by using Quinlan's C4.5 decision-tree learning algorithm. We extract a noun describing a video object and a verb describing an action for each video shot. To show the effectiveness of the method, we conducted experiments on the extraction of video segments in which animals appear and perform actions in twenty episodes of a Nature program. We obtained F-values of 0.609 on the extraction of video segments in which animals appear and 0.699 on extracting the action of "eating." We applied our method to a further 20 episodes, and generated a multimedia encyclopedia of animals. This provided a total of 387 video clips of 105 kinds of animals and 261 video clips of 56 kinds of actions.
ASSIST IN COOKING: ACTION SUPPORT SYSTEM FOR INTERACTIVE SELF-TRAINING
Authors: MEGA SATORU , FADIL YOUNES , HORIE ARATA , UEHARA KUNIAKI
Published: November 2008

Human-computer interaction systems have been developed in recent years. These systems use multimedia techniques to create Mixed-Reality environments where users can train themselves. Although most of these systems rely strongly on interactivity with the users, taking into account users' states, they still lack the possibility of considering users preferences when they help them. In this paper, we introduce an Action Support System for Interactive Self-Training (ASSIST) in cooking. ASSIST focuses on recognizing users' cooking actions as well as real objects related to these actions to be able to provide them with accurate and useful assistance. Before the recognition and instruction processes, it takes users' cooking preferences and suggests one or more recipes that are likely to satisfy their preferences by collaborative filtering. When the cooking process starts, ASSIST recognizes users' hands movement using a similarity measure algorithm called AMSS. When the recognized cooking action is correct, ASSIST instructs the user on the next cooking procedure through virtual objects. When a cooking action is incorrect, the cause of its failure is analyzed and ASSIST provides the user with support information according to the cause to improve the user's incorrect cooking action. Furthermore, we construct parallel transition models from cooking recipes for more flexible instructions. This enables users to perform necessary cooking actions in any order they want, allowing more flexible learning.