bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Snow Albedo in Land Models for Weather and Climate Studies
Authors: Wang Zhuo , Zeng Xubin
Published: October 2009

Snow albedo plays an important role in land models for weather, climate, and hydrometeorological studies, but its treatment in various land models still contains significant deficiencies. Complementary to previous studies that evaluated the snow albedo as part of an overall land model study, the snow albedo formulations as used in four major weather forecasting and climate models [European Centre for Medium-Range Weather Forecasts (ECMWF), National Centers for Environmental Prediction (NCEP) “Noah” land model, National Center for Atmospheric Research (NCAR) Community Land Model (CLM3), and NCEP global model] were directly evaluated here using multiyear Boreal Ecosystem–Atmosphere Study (BOREAS) in situ data over grass and forest sites. First, four idealized cases over grass and forest sites were designed to understand better the different albedo formulations in these models. Then the BOREAS data were used to evaluate snow albedo and relevant formulations and to identify deficiencies of each model. Based on these analyses, suggestions that involve only minor changes in parameters or formulations were made to significantly reduce these deficiencies of each model. For the ECMWF land model, using the square root of snow water equivalent (SWE), rather than SWE itself, in the computation of snow fraction would significantly reduce the underestimation of albedo over grass. For the NCEP Noah land model, reducing (increasing) the critical SWE for full snow cover over short (tall) vegetation would reduce the underestimate (overestimate) of snow albedo over the grass (forest) site. For the NCAR CLM3, revising the coefficient used in the ground snow-fraction computation would substantially reduce the albedo underestimation over grass. For the albedo formulations in the NCEP global model, replacing the globally constant fresh snow albedo by the vegetation-type-dependent Moderate-Resolution Imaging Spectroradiometer (MODIS) maximum snow albedo would significantly improve the overestimation of model albedo over forest.
Dynamical Feedbacks and the Persistence of the NAO
Authors: Barnes Elizabeth A. , Hartmann Dennis L.
Published: October 2009

The persistence of the North Atlantic Oscillation (NAO) is studied using observations of the three-dimensional vorticity budget in the Atlantic sector. Analysis of the relative vorticity tendency equation shows that convergence of eddy vorticity flux in the upper troposphere counteracts the effect of anomalous large-scale divergence at the upper level. At low levels, the convergence associated with this large-scale vertical circulation cell maintains the relative vorticity anomaly against frictional drag. The eddy vorticity flux convergence thus acts to sustain the vorticity anomaly associated with the NAO against drag and increases the persistence of the NAO vorticity anomaly. The adiabatic cooling associated with the rising motion in the vorticity maximum sustains the thermal structure of the NAO anomaly, enhancing the baroclinicity, and thus eddy generation. This constitutes a positive eddy feedback that helps maintain the NAO. The positive eddy feedback occurs only in the midlatitude region and is strongest during the negative phase of the NAO when the Atlantic jet is displaced toward the equator, with a high pressure anomaly to the north and a low pressure anomaly to the south. The stronger feedback demonstrated during the negative phase is consistent with the greater persistence observed for this phase of the NAO. The positive feedback appears to be associated with anomalous northward eddy propagation away from the jet.
Cloud-Resolving Simulation of Low-Cloud Feedback to an Increase in Sea Surface Temperature
Authors: Xu Kuan-Man , Cheng Anning , Zhang Minghua
Published: October 2009

This study investigates the physical mechanisms of the low cloud feedback through cloud-resolving simulations of cloud-radiative equilibrium response to an increase in sea surface temperature (SST). Six pairs of perturbed and control simulations are performed to represent different regimes of low clouds in the subtropical region by specifying SST differences (ΔSST) in the range of 4 and 14 K between the warm tropical and cool subtropical regions. The SST is uniformly increased by 2 K in the perturbed set of simulations. Equilibrium states are characterized by cumulus and stratocumulus cloud regimes with variable thicknesses and vertical extents for the range of specified ΔSSTs, with the perturbed set of simulations having higher cloud bases and tops and larger geometric thicknesses. The cloud feedback effect is negative for this ΔSST range (−0.68 to −5.22 W m−2 K−1) while the clear-sky feedback effect is mostly negative (−1.45 to 0.35 W m−2 K−1). The clear-sky feedback effect contributes greatly to the climate sensitivity parameter for the cumulus cloud regime whereas the cloud feedback effect dominates for the stratocumulus regime. The increase of liquid water path (LWP) and cloud optical depth is related to the increase of cloud thickness and liquid water content with SST. The rates of change in surface latent heat flux are much higher than those of saturation water vapor pressure in the cumulus simulations. The increase in surface latent heat flux is the primary mechanism for the large change of cloud physical properties with +2 K SST, which leads to the negative cloud feedback effects. The changes in cloud fraction also contribute to the negative cloud feedback effects in the cumulus regime. Comparison of these results with prior modeling studies is also discussed.
U.K. HiGEM: Simulations of Desert Dust and Biomass Burning Aerosols with a High-Resolution Atmospheric GCM
Authors: Woodage M. J. , Slingo A. , Woodward S. , Comer R. E.
Published: October 2009

The atmospheric component of the United Kingdom’s new High-resolution Global Environmental Model (HiGEM) has been run with interactive aerosol schemes that include biomass burning and mineral dust. Dust emission, transport, and deposition are parameterized within the model using six particle size divisions, which are treated independently. The biomass is modeled in three nonindependent modes, and emissions are prescribed from an external dataset. The model is shown to produce realistic horizontal and vertical distributions of these aerosols for each season when compared with available satellite- and ground-based observations and with other models. Combined aerosol optical depths off the coast of North Africa exceed 0.5 both in boreal winter, when biomass is the main contributor, and also in summer, when the dust dominates. The model is capable of resolving smaller-scale features, such as dust storms emanating from the Bodélé and Saharan regions of North Africa and the wintertime Bodélé low-level jet. This is illustrated by February and July case studies, in which the diurnal cycles of model variables in relation to dust emission and transport are examined. The top-of-atmosphere annual mean radiative forcing of the dust is calculated and found to be globally quite small but locally very large, exceeding 20 W m−2 over the Sahara, where inclusion of dust aerosol is shown to improve the model radiative balance. This work extends previous aerosol studies by combining complexity with increased global resolution and represents a step toward the next generation of models to investigate aerosol–climate interactions.
Indian Ocean Dipole Response to Global Warming: Analysis of Ocean–Atmospheric Feedbacks in a Coupled Model*
Authors: Zheng Xiao-Tong , Xie Shang-Ping , Vecchi Gabriel A. , Liu Qinyu , Hafner Jan
Published: October 2009

Low-frequency modulation and change under global warming of the Indian Ocean dipole (IOD) mode are investigated with a pair of multicentury integrations of a coupled ocean–atmosphere general circulation model: one under constant climate forcing and one forced by increasing greenhouse gas concentrations. In the unforced simulation, there is significant decadal and multidecadal modulation of the IOD variance. The mean thermocline depth in the eastern equatorial Indian Ocean (EEIO) is important for the slow modulation, skewness, and ENSO correlation of the IOD. With a shoaling (deepening) of the EEIO thermocline, the thermocline feedback strengthens, and this leads to an increase in IOD variance, a reduction of the negative skewness of the IOD, and a weakening of the IOD–ENSO correlation.

In response to increasing greenhouse gases, a weakening of the Walker circulation leads to easterly wind anomalies in the equatorial Indian Ocean; the oceanic response to weakened circulation is a thermocline shoaling in the EEIO. Under greenhouse forcing, the thermocline feedback intensifies, but surprisingly IOD variance does not. The zonal wind anomalies associated with IOD are found to weaken, likely due to increased static stability of the troposphere from global warming. Linear model experiments confirm this stability effect to reduce circulation response to a sea surface temperature dipole. The opposing changes in thermocline and atmospheric feedbacks result in little change in IOD variance, but the shoaling thermocline weakens IOD skewness. Little change under global warming in IOD variance in the model suggests that the apparent intensification of IOD activity during recent decades is likely part of natural, chaotic modulation of the ocean–atmosphere system or the response to nongreenhouse gas radiative changes.
A Parsimonious Stochastic Water Reservoir: Schreiber’s 1904 Equation
Authors: Fraedrich Klaus
Published: October 2009

A parsimonious model is presented, leading to Schreiber’s aridity–runoff relation as equilibrium solution of the rainfall–runoff chain. The chain commences with a fast stochastic water reservoir of small capacity, representing interception and wetted ground in short time intervals. It feeds a slow (almost stationary) soil moisture reservoir of large capacity, balancing its runoff after long-term averaging. Parameterizing the fast reservoir’s capacity by the water equivalent of net radiation available for evaporation leads to a biased coin-flip surrogate for its “full” or “empty” states when rainfall is larger or smaller than the capacity. Rainfall surplus from the fast reservoir’s full state feeds the slow (almost stationary) soil moisture reservoir; with the residual evaporating the fast reservoir starts anew as empty. Rainfall below capacity evaporates completely and, leaving the energy surplus for sensible heat, the fast reservoir also starts anew as empty. Employing coin-flip occurrence probabilities from exponentially distributed precipitation yields Schreiber’s formula.
Characteristics of Mesoscale Eddies in the Kuroshio–Oyashio Extension Region Detected from the Distribution of the Sea Surface Height Anomaly
Authors: Itoh Sachihiko , Yasuda Ichiro
Published: October 2009

This study investigates the distribution of the sea surface height anomaly (SSHA) with the aim of quantifying the characteristics of mesoscale eddies in the Kuroshio–Oyashio extension region (KOER), where intense mesoscale eddies are commonly observed during hydrographic surveys. Dense distributions of both anticyclonic eddies (AEs) and cyclonic eddies (CEs) are detected for the first time in KOER with sufficient temporal and spatial coverage, using the Okubo–Weiss parameter without smoothing. Their contribution to the total SSHA variance is estimated to be about 50%. The zones of highest amplitudes are located north and south of the axis of the Kuroshio Extension (KE) for AEs and CEs, which represent warm-core and cold-core rings, respectively; the areas extend poleward along the Japan and Kuril–Kamchatka Trenches, especially for AEs. Eddies of both polarities and with moderate amplitudes are also recognized along the Subarctic Front (SAF). Eddies in areas north and south of the KE generally propagate westward, at a mean rate of 1–5 cm s−1; those along the trenches south of 46°N and along the SAF propagate poleward at mean rates of 1–2 and 0.5–1 cm s−1, respectively. Because of the asymmetric distribution of the AEs and CEs in the areas north and south of the KE, and the asymmetric amplitude of them along the Japan and Kuril–Kamchatka Trenches, there exist significant eddy fluxes of vorticity, heat, and salinity in these areas.
Comparison of the Infrared Surface Emissivity Model (ISEM) with a Physical Emissivity Model
Authors: Hong Sungwook , Shin Inchul , Ou Mi-Lim
Published: October 2009

Accurate models of surface emissivity are important for interpreting satellite radiance observations. Surface emissivity depends on the satellite zenith angle, roughness, polarization, and refractive index of the surface. The effects of the roughness parameter on emissivity have not been studied thoroughly. By using an infrared geostationary satellite observation and a physical model based on the radiative transfer equation, the forward emissivity model and physical emissivity model are validated in the northwestern Pacific Ocean. First, the unpolarized emissivity at a given view angle and a wavelength of 10.8 μm in the thermal infrared spectral region is decomposed for the clear sky. The refractive index of the sea surface is quantitatively retrieved using the inversion of Fresnel equations. The refractive index of the sea surface derived from the physical emissivity exhibits a reasonable range within the infrared wavelength. The result of this investigation can be applied to the land emissivity model, which has not been studied thoroughly.
The Life Cycle of an Undular Bore and Its Interaction with a Shallow, Intense Cold Front
Authors: Hartung Daniel C. , Otkin Jason A. , Martin Jonathan E. , Turner David D.
Published: October 2009

The evolution of an undular bore and its associated wind shift, spawned by the passage of a shallow surface cold front over the Southern Great Plains of the United States, is examined using surface and remote sensing observations along with output from a high-resolution numerical model simulation. Observations show that a separation between the wind shift and thermodynamic properties of the front was induced by the formation of a bore over south-central Kansas around 0200 UTC 29 November 2006. By the time the front–bore complex passed through Lamont, Oklahoma, approximately 4 h later, the bore had reached its maximum intensity and its associated wind shift preceded the trailing baroclinic zone by 20 min. Within several hours the bore decayed and a cold frontal passage, characterized by a wind shift coincident with thermodynamic properties was observed at Okmulgee, Oklahoma. Thus, a substantial transformation in both the structural and dynamical characteristics of the bore as well as its relationship to the parent surface front occurred during a short period of time.

The details of this evolution are examined using output from a finescale numerical simulation, performed using the Weather Research and Forecasting (WRF) model. Analysis of the output reveals that as the bore advanced southeastward it moved into a region with a weaker surface stable layer. Consequently, the wave duct that had supported its maintenance steadily weakened resulting in dissipation of the bore. This circumstance led to a merger of the surface temperature and moisture boundaries with the orphaned wind shift, resulting in the cold frontal passage observed at Okmulgee.
A Quasi-Variational Algorithm for Nonlinear Normal-Mode Initialization
Authors: Bourchtein Andrei
Published: October 2009

Balance equations of normal-mode initialization are nonlinear time-independent partial differential equations solved by iterative methods. For the given geopotential, there are regions where these equations are not elliptic, which is reflected in the divergence of iterative algorithms. Variational approaches used to minimize the geopotential changes are more expensive than conventional methods. In this study a simple quasi-variational algorithm is proposed based on different forms of normal-mode initialization equations, which achieves a good balance of atmospheric fields and ensures small changes of geopotential analysis values.
Comparison of Ensemble Kalman Filters under Non-Gaussianity
Authors: Lei Jing , Bickel Peter , Snyder Chris
Published: October 2009

Recently various versions of ensemble Kalman filters (EnKFs) have been proposed and studied. This work concerns, in a mathematically rigorous manner, the relative performance of two major versions of EnKF when the forecast ensemble is non-Gaussian. The approach is based on the stability of the filtering methods against small model violations, using the expected squared L2 distance as a measure of the deviation between the updated distributions. Analytical and experimental results suggest that both stochastic and deterministic EnKFs are sensitive to the violation of the Gaussian assumption, while the stochastic filter is relatively more stable than the deterministic filter under certain circumstances, especially when there are wild outliers. These results not only agree with previous empirical studies, but also suggest a natural choice of a free parameter in the square root Kalman filter algorithm.
Nocturnal Tornado Climatology*
Authors: Kis Amanda K. , Straka Jerry M.
Published: October 2009

Very few studies on nocturnal tornadoes have been performed, and operational forecasting of nocturnal tornadoes is often guided by the results of studies that are biased toward daytime tornadoes. However, it is likely that tornado environments vary significantly over the diurnal cycle. For example, the depth and nature of storm inflow may change as the daytime boundary layer transitions into a stable nighttime boundary layer, and a low-level jet (LLJ) may form above in the residual layer and free atmosphere. The study performed herein is used to investigate features unique to nocturnal boundary layers and the free atmosphere above that may affect nocturnal tornadoes.

A climatology of significant (F2–F5) nocturnal tornadoes in the contiguous United States between 2004 and 2006 shows that environments deemed by previous climatologies as unfavorable for late afternoon/early evening tornadogenesis are in fact conducive to significant nocturnal tornadogenesis. These nocturnal environments may be characterized by marginal convective instability with shallow stable boundary layers. Substantial low-level shear, storm relative helicity (SREH), and exceptionally strong nocturnal low-level jets stand out as the most common features of significant nocturnal tornadoes and have utility in distinguishing environments of weak nocturnal tornadoes from environments of significant nocturnal tornadoes. Analysis of the data gathered in the climatology shows that the suggestions of existing tornado climatologies are inadequate and even misguiding for forecasting nocturnal tornadoes. Several recommendations for operational forecasting of nocturnal tornadoes are made based on the results of this climatology.
Application of Spatial Verification Methods to Idealized and NWP-Gridded Precipitation Forecasts
Authors: Ahijevych David , Gilleland Eric , Brown Barbara G. , Ebert Elizabeth E.
Published: October 2009

Several spatial forecast verification methods have been developed that are suited for high-resolution precipitation forecasts. They can account for the spatial coherence of precipitation and give credit to a forecast that does not necessarily match the observation at any particular grid point. The methods were grouped into four broad categories (neighborhood, scale separation, features based, and field deformation) for the Spatial Forecast Verification Methods Intercomparison Project (ICP). Participants were asked to apply their new methods to a set of artificial geometric and perturbed forecasts with prescribed errors, and a set of real forecasts of convective precipitation on a 4-km grid. This paper describes the intercomparison test cases, summarizes results from the geometric cases, and presents subjective scores and traditional scores from the real cases.

All the new methods could detect bias error, and the features-based and field deformation methods were also able to diagnose displacement errors of precipitation features. The best approach for capturing errors in aspect ratio was field deformation. When comparing model forecasts with real cases, the traditional verification scores did not agree with the subjective assessment of the forecasts.
Alien Rule and Its Discontents
Authors: Hechter Michael
Published: October 2009

It is commonplace to explain nationalist movements by adverting to the demand for national self-determination. Indeed, nationalism is frequently defined in precisely these terms. Discontent with alien rule—the obverse of national self-determination—is often assumed to be pervasive, if not universal, thus accounting for the absence of an international market in governance services. There is no shortage of explanations of the antipathy to alien rule and a great deal of corroborative evidence. Many believe that people seem to prefer to be badly ruled by their own kind than better ruled by aliens. Yet if this is true, then identity trumps competence in the assessment of rule, implying that we are all liable to suffer from suboptimal governance. In contrast, this article argues that the evidence for the pervasiveness of antipathy to alien rule is overdrawn. To that end, it distinguishes between two different types of alien rule, elected and imposed; provides a brief portrait of each; and suggests that when aliens are confronted with incentives to rule fairly and efficiently, they can gain legitimacy even when they have been imposed. This conclusion has implications for the prospects of an international market in governance services.
Creating Political Legitimacy
Authors: Rothstein Bo
Published: October 2009

It is often held that the establishment of electoral democracy is key to the creation of political legitimacy. This article challenges this idea and presents an alternative. Many empirical studies reveal that electoral democracy has no necessary implications for the establishment of legitimacy. Even in the successful and stable Nordic democracies, there is scant evidence that legitimacy is created on the input side of the political system. For example political legitimacy in the former Yugoslavia broke down not because ethnic groups realized they would become permanent minorities but because the new Croatian state violated citizens’ rights in the exercise of power. Legitimacy turns out to be created, maintained, and destroyed not at the input but at the output side of the political system. Hence, political legitimacy depends at least as much on the quality of government than on the capacity of electoral systems to create effective representation.
Conceptualizing Legitimacy, Measuring Legitimating Beliefs
Authors: Levi Margaret , Sacks Audrey , Tyler Tom
Published: October 2009

Legitimacy is a concept meant to capture the beliefs that bolster willing obedience. The authors model legitimacy as a sense of obligation or willingness to obey authorities (value-based legitimacy) that then translates into actual compliance with governmental regulations and laws (behavioral legitimacy). The focus is on the factors that elicit this sense of obligation and willingness to comply in a way that supports rational-legal authority. The framework posits that legitimacy has two antecedent conditions: trustworthiness of government and procedural justice. Using African survey data, the authors model the relationship between the existence of a relatively effective, fair, and trustworthy government and beliefs that government deserves deference to its rules. The authors find considerable evidence of a link between the extent of the trustworthiness of government and procedural justice and citizens’ willingness to defer to the police, courts, and tax department in a wide range of African societies.
Power and Justice
Authors: Hegtvedt Karen A. , Johnson Cathryn
Published: October 2009

Legitimacy generally compels people to feel an obligation to follow the social rules dictated by an authority. While much social psychological research focuses on the consequences of legitimacy, far less pertains to its emergence. Here the authors examine the role of justice and power in establishing the legitimacy of a decision maker. The authors outline the identity-based model offered by Tyler that highlights the role of procedural justice and offer a complementary resource-based model. The authors argue that the power structure in an organization and the nature of power use by authorities affect the availability of the material and nonmaterial resources necessary for subordinates to do their jobs well, which in turn creates social obligations that allow for the germination of legitimacy. With emphasis on resources, the analysis thus reconsiders the role of distributive justice. The authors conclude by emphasizing the conditions under which identity concerns and resource concerns are relevant to the emergence of legitimacy and by speculating on how these social psychological processes may parallel arguments in this volume regarding the emergence of state legitimacy.
The Mandate of Heaven and Performance Legitimation in Historical and Contemporary China
Authors: Zhao Dingxin
Published: October 2009

This article argues that performance legitimacy, an aspect of state legitimacy neglected by Weber in his original formulation of the theory of domination, played a particularly important role in the history of China and has shaped not only the patterns of Chinese history but also today’s Chinese politics. Yet, performance legitimacy is intrinsically unstable because it carries concrete promises and therefore will trigger immediate political crisis when the promises are unfulfilled. This problem is especially profound for a modern state once its power is based primarily on performance because modern states tend to be development rather than maintenance oriented and promise too much. Therefore, although the current government expends much effort to heighten its legitimacy by improving its performance, it will face a major crisis when the Chinese economy cools off unless it establishes legal-electoral legitimacy.
Mass Persuasion as a Means of Legitimation and China’s Popular Authoritarianism
Authors: Brady Anne-Marie
Published: October 2009

States traditionally maintain power by means of either performance-based legitimacy or promulgating ideology. Mass persuasion can be used to both promote a regime’s ideology and persuade the public that it is performing the tasks of government effectively and equitably. Most states use a combination of these two approaches to maintain political stability. In China, since the violent crackdown on the 1989 protest movement, the Chinese Communist Party (CCP) government has stressed an old slogan to set a new line on its format for maintaining political power: “Seize with both hands; both hands must be strong.” This means that the CCP now bases its legitimacy on both economic growth and a renewed emphasis on persuasion, or what in Chinese terms is known as propaganda and thought work. The two “hands” in this slogan are strong and intertwined, as the key themes of propaganda and thought work in the current period are promoting economic growth, building market confidence, and engaging in economic thought reform. In an extraordinary process of cultural exchange, in recent years China’s propaganda system has deliberately absorbed the methodology of political public relations, mass communications, social psychology, and other modern methods of mass persuasion commonly used in Western democratic societies, adapting them to Chinese conditions and needs. China’s modern-day propaganda and thought work is now market friendly, scientific, high tech, and politics-lite. Focusing on the years from 1989 to 2007, this article uses the case of contemporary China to examine the role of mass persuasion as a force for maintaining and, in China’s case, reclaiming political legitimacy to rule and introduces a new term to understand the China model, popular authoritarianism.
Legitimacy and Public Administration
Authors: Catlaw Thomas J. , Hu Qian
Published: October 2009

Legitimacy claims can only be made and processes of legitimation can only unfold in a specified context. This article uses Pierre Bourdieu’s concept of the social field to name this context and to analyze the construction of the bureaucratic or public administrative field in the United States. Field is meant in a triple sense—public administration as a general, institutionalized field in the structure of government; public administration as a professional field; and public administration as an academic field of study. Thus, rather than the bureaucratic field, the relationship of these bureaucratic field s or an “ensemble of fields” is analyzed to consider how each field both bounds its own legitimation struggles and draws from other fields for symbolic resources—what Bourdieu called symbolic capital —to establish its legitimacy and position. The multifield quality of public administration is used to show how the nature of the general bureaucratic field is distinct from other fields insofar as it purports to represent a universal, general interest. This difference is used to theorize a distinction between “general” and “specific” legitimation processes.
A World Ranking of the Top 100 Hospitality and Tourism Programs
Authors: Severt Denver E. , Tesone Dana V. , Bottorff Timothy J. , Carpenter Monica L.
Published: October 2009

The article provides an analysis of scholarly contributions to 11 hospitality and tourism refereed journals for the years 2002 to 2006. It presents the top 100 programs as ranked by instances of publications across 11 journals for a recent 5-year period. For the 5-year period, results indicate The Hong Kong Polytechnic University in the top position based on sums of instances, authors, and articles. Second, the researchers updated, modified, and extended a previous study published by the Journal of Hospitality & Tourism Research for similar information for the years 1992 to 2001. Following the update, an additional 15-year aggregate snapshot of research output for top producing institutions provided a top 18 over the last 15-year period. Next, researchers provide an updated analysis by contribution and world region among the specific journals with results indicating a large growth in the number of articles produced in Asia going from 6% of all publications over the earlier 10-year period from 1992 through 2001 to nearly 15% of published articles over the past 5-year period from 2002 through 2006. The article concludes with suggestions for the extension of similar studies and provides implications for hospitality and tourism educators.
Dining for Safety: Consumer Perceptions of Food Safety and Eating Out
Authors: Knight Andrew J. , Worosz Michelle R. , Todd Ewen C. D.
Published: October 2009

This study investigates whether perceptions about food safety are related to how often consumers eat at restaurants. More specifically, it examines how the following affect the frequency of eating at restaurants: (a) concern about food safety issues, (b) food safety performance of restaurants, (c) how often consumers think about food safety, (d) the belief of having had food poisoning, (e) knowledge about food safety, and (f) sociodemographic variables. Using data from a nationwide telephone survey conducted with 1,014 randomly selected U.S. adults, the results indicated that perceptions of food safety do influence how often consumers eat at restaurants. Concern about food safety issues, thinking about food safety, and having experienced food poisoning were related to frequency of dining out. When comparing those who eat at restaurants rarely, occasionally, and often, most of the significant differences were between those who eat at restaurants rarely and those who dine out occasionally or often.
The Roles of the Physical Environment, Price Perception, and Customer Satisfaction in Determining Customer Loyalty in the Restaurant Industry
Authors: Han Heesup , Ryu Kisang
Published: October 2009

This research aims to examine the relationships among three components of the physical environment (i.e., décor and artifacts, spatial layout, and ambient conditions), price perception, customer satisfaction, and customer loyalty in the restaurant industry. A total of 279 cases from a survey were used to assess overall fit of the proposed model and test hypotheses using structural equation modeling. The three factors of the physical environment strongly influenced how customers perceived price, and this price perception, in turn, enhanced customer satisfaction level and directly/indirectly influenced customer loyalty. Décor and artifacts were the most significant predictors of price perception among the three components of the physical environment. Furthermore, both price perception and customer satisfaction played significant partial/complete mediating roles in the proposed model. The paper provides potential ways for restaurateurs to increase customer loyalty by improving their understanding of the roles of physical environment, price perception, and customer satisfaction.
Activity-Based Costing in the Hospitality Industry: Evidence From Greece
Authors: Pavlatos Odysseas , Paggios Ioannis
Published: October 2009

The purpose of this article is to provide some empirical evidence of the current general trends regarding the practical consideration, adoption, and use of activity-based costing (ABC) in the hospitality industry. To this end, a survey was conducted with 85 firms of the Greek hotel sector with the use of questionnaires. Results showed that the adoption rate of an ABC system could be considered rather satisfactory. For the hotels that have adopted ABC, the survey showed that they apply it throughout all the core areas of management accounting, especially in pricing decisions and customer’s profitability analysis. The nonusers reported that the main reason for rejecting it is the satisfaction of the existing cost accounting system and the high cost of an ABC implementation.
Country Club Members’ Perceptions of Value, Image Congruence, and Switching Costs: an Exploratory Study of Country Club Members’ Loyalty
Authors: Back Ki-Joon , Lee Jin-Soo
Published: October 2009

The objective of this study was to investigate the relationships among perceived value, member satisfaction, switching costs, and member loyalty in the country club industry. In particular, this study sought to ascertain the mediating role of member satisfaction in the relationships centered on value—loyalty and image congruence—loyalty and the moderating role of switching costs in the member satisfaction—loyalty relationship. The results revealed a significant mediating effect of member satisfaction, whereas switching costs did not play a significant moderating role in the member satisfaction—loyalty relationship. Findings from this study will enhance understanding of how to cultivate club member loyalty.
The Use of Acceptable Customer Waiting Times for Capacity Management in a Multistage Restaurant
Authors: Hwang Johye , Lambert Carolyn U.
Published: October 2009

This study took an integrated approach to restaurant capacity management by capturing major types of capacity and multiple stages of service and incorporating customers’ expectations. A simulation was used to measure the current restaurant’s performance in meeting the waiting time standards and to identify the threshold requirements of resources to meet the different levels of customer expectations of waiting times. The results showed that the current restaurant needed to adjust capacity levels to meet the customer service standards, and more than one combination of multiresource thresholds existed because the threshold level of each resource varied with the other types of resources.
Microjoining of Ni3Al based intermetallic thin foils
Authors: Jozwik P. , Bojar Z. , Kołodziejczak P.
Published: October 2009

A preliminary analysis of the joining ability of thin Ni3Al (Zr, B) based foils (below 150 μm thickness) into ‘honeycomb’ structures by various techniques is described in this work. Resistance welding, CO2 laser welding and microplasma arc welding, as well as explosive welding, were used in the investigations. The examinations conducted in this study of the joint microstructures obtained by each technique do not reveal the existence of a heat affected zone. Columnar grains with a longer axis, as determined by the direction of heat flow, were observed along the fusion lines. Changes in microhardness were also examined along with a microanalysis of the chemical composition of the joint cross-section. Preliminary tests of the joining of thin Ni3Al foil into ‘honeycomb’ experimental structures were carried out.
Evaluation and application of a fast EBSD detector
Authors: Brough I. , Humphreys F. J.
Published: October 2009

A Nordlys F, fast electron backscatter diffraction camera has been used on a CamScan MX2500 field emission gun SEM in conjunction with a hot stage to study annealing phenomena in metals. The performance of the camera under a wide variety of conditions has been evaluated, and comparison is made with a conventional electron backscatter diffraction camera operating under the same conditions and with the same samples. Examples are given of applications of the system to the annealing of aluminium alloys.
Microstructure and mechanical properties of nickel based superalloy IN718 produced by rapid prototyping with electron beam melting (EBM)
Authors: Strondl A , Palm M , Gnauk J , Frommeyer G
Published: October 2009

A nickel alloy of a composition similar to that of the nickel based superalloy Inconel alloy 718 (IN718) was produced with the electron beam melting (EBM) process developed by Arcam AB. The microstructures of the as processed and heat treated material are similar to that of conventionally produced IN718, except that the EBM material showed some porosity and the δ phase did not dissolve during the solution heat treatment because the temperature of 1000°C apparently was too low. Mechanical testing of the layer structured material, parallel and perpendicular to the built layers, revealed sufficient strength in both directions. However, it showed only limited elongation when tested perpendicular to the built layers due to local agglomerations of pores. Otherwise, data for the hardness, Young's modulus, 0·2 yield tensile strength and ultimate tensile strength match those recommended for IN718.
Study on Young's modulus and microhardness of carbon nanotubes reinforced copper nanocomposite
Authors: Patil R. G. , Chatpalli V. , Kannan K. R.
Published: October 2009

Carbon nanotubes (CNTs) were discovered by Iijima in 1991 as the fourth form of carbon. Carbon nanotubes are the ultimate form of the carbon fibre because of its high Young's modulus in the order of 1 TPa, which is very useful for load transfer in nanocomposites. In the present work, CNT/Cu nanocomposites were fabricated by the powder metallurgy technique, and after extrusion of the nanocomposites, bright field transmission electron microscopic studies were carried out. From the transmission electron microscopic images obtained, a novel method of ascertaining the Young's modulus of multiwalled CNTs is worked out in the present paper, which turns out to be 0·94 TPa, which is consistent with experimental results. Furthermore, an attempt is made to investigate the microhardness of copper by reinforcing it with multiwalled CNTs. There is an increase in hardness by twofold in CNT/Cu nanocomposites as compared to pure Cu matrix. This is due to high relative density, even distribution of CNTs and proper bonding at CNT/Cu interfaces.
Characterisation of aluminium nanopowder produced by evaporation–condensation method
Authors: Hosseini S. H. , Sheibani S. , Valefi Z.
Published: October 2009

In the present paper, aluminium nanoparticles were produced using evaporation of metal at high temperatures, 1500°C, and subsequent cooling in cold argon gas. The samples were characterised in terms of composition, morphology, structure, particle size and surface area using complementary techniques such as X-ray diffraction, scanning electron microscopy, electron dispersive spectroscopy and the Brunauer–Emmett–Teller method. It was found that the nanoparticles were covered by a crystalline oxide layer. In addition, the Brunauer–Emmett–Teller results showed that the produced nanoparticles reached an average diameter of 85 nm under modified condition. Thermal analysis showed that the reactivity was affected by average particle diameter, size distribution and crystallinity of passivating oxide layer. The produced aluminium nanoparticles were compared with the micrometre sized and commercially available aluminium explosive (Alex) nanopowder. Results showed that the reactivity of broad size distribution Alex nanopowder is analogous to the narrow size distribution produced nanopowder even though the average particle size is larger for the Alex nanopowder.
Overload failure behaviour of dissimilar thickness resistance spot welds during tensile shear test
Authors: Marashi S. P. H. , Pouranvari M. , Salehi M. , Abedi A. , Kaviani S.
Published: October 2009

Resistance spot welding is the dominant process for joining sheet metals in automotive industry. Even thickness combinations are rarely used in practice; therefore, there is clearly a practical need for failure behaviour investigation of uneven thickness resistance spot welds. The aim of the present paper is to investigate the failure mode and failure mechanism of dissimilar thickness low carbon steel resistance spot welds during tensile shear overload test. Microstructural investigations, microhardness tests and tensile shear tests were conducted. Mechanical properties of the joints were described in terms of peak load, energy absorption and failure mode. In order to understand the failure mechanism, micrographs of the cross-sections of the spot welded joints during and after tensile shear are examined by optical microscopy. It was found that for well established weld nuggets, the final solidification line is located in the geometrical centre of the joint. In pull-out failure mode, failure is initiated by necking of the base metal at the thinner thickness sheet. Finally, it was concluded that weld nugget size, weld penetration and the strength of the thinner sheet are the main controlling factors of the peak load and energy absorption of dissimilar thickness spot welds.
Multisheet structure of Inconel 718 superalloy processed by LBW/SPF technology and its microstructure
Authors: Qu F. S. , Zhang K. F. , Li B. Y.
Published: October 2009

Multisheet structure of Inconel 718 superalloy will be widely used in vehicles as heat resisting and heat shielding structure due to its lightweight, high strength and stiffness. Multisheet structure of Inconel 718 superalloy was processed by laser beam welding and superplastic forming (LBW/SPF) technology in the present paper. Multisheet structure of Inconel718 superalloy processed by LBW/SPF technology exhibits good configuration and uniform thickness distribution. Laser beam welding parameters for multisheet structure were as follows: pulse frequency was 32 Hz; pulse duration 3 ms; peak power per pulse 4500 W; welding speed 180 mm min–1; SPF parameters were as follows: temperature Tf=965°C; forming pressure Pf=4·2 MPa; forming time tf=130 min. Microstructure of multisheet structure was studied carefully. Microstructure in weld fusion zone was constituted of austenite dendritics and Laves phase precipitated in interdendritics. After SPF process, austenite dendritics in the weld fusion became coarser and most of Laves phases were dissolved and turned into δ precipitated phase but a few of Laves phases were still reserved. And Nb concentration in dendritics increased to 5·42% compared to 2·82% under as welded condition. Weld metal hardness increased from 331·63 under as welded condition to 391·74 under post-SPF condition which was closed to the base material hardness of post-SPF. Grain size of base material grew slightly and an amount of precipitated phase appeared in the base material undergoing SPF process. The tensile test results of base material show that tensile strength increased obviously and the ductility decreased slightly after SPF process. Therefore, LBW/SPF technology is an appropriate forming technique for multisheet structure of Inconel 718 superalloy.
Microstructures and mechanical properties of tungsten inert gas arc welded magnesium metal matrix composite (TiCp/AZ91D)
Authors: Xuan Z. Z. , Gu X. Y. , Zhong R. , Sun D. Q.
Published: October 2009

Magnesium metal matrix composite (TiCP/AZ91D) was joined by tungsten inert gas arc welding with addition of filler metal (TiCP/AZ91D). The weld metal (WM) consists of TiC particulates, primary α-Mg and eutectic phases (eutectic α-Mg and eutectic β-Mg17Al12). TiC particulates distribute at primary α-Mg grain boundaries or inside the grains depending on the particulate size. At the grain boundaries, there exist divorced eutectic and lamellar eutectic microstructures due to rapid cooling rates. The pores accumulated are observed in the WM. In the heat affected zone, its microstructures have a coarsening tendency and microcracks form at the grain boundaries. The WM has the tensile strength of 140–190 MPa and the elongation of 1–3%. The tensile strength and elongation of welded joint are 130–160 MPa and 0–1% respectively. The pores accumulated, microcracks and grain coarsening are the main reasons to affect the mechanical properties of WM and welded joint.
Interface evolution of SiO2 glass ceramic and Ti–6Al–4V alloy joint brazed with Ag–Cu–Ti alloy
Authors: Liu D. , Zhang L. X. , Feng J. C. , Liu H. B. , He P.
Published: October 2009

In the present paper, SiO2 glass ceramic and Ti–6Al–4V alloy were successfully brazed with Ag–21Cu–4·5Ti active braze alloy. The interfacial microstructure and evolution course of SiO2 glass ceramic/Ti–6Al–4V joint were studied in detail. According to the experimental results, active element Ti plays a quite important role in the formation of reaction layers on the joint interface. The reaction products of the joint are TiSi2, Ti4O7, TiCu, Cu2Ti4O and Ti2Cu respectively. The interface evolution can be generally described by four stages, which are solution and diffusion of atoms, reaction among atoms, formation of reaction layers and precipitation of solid solution layers respectively.
Improving high temperature properties of alumina based ceramic cores containing yttria by vacuum impregnating
Authors: Wu H H , Li D C , Tang Y P , Chen X J , Xu D Y , Sun B
Published: October 2009

Ceramic cores used in investment casting for directional solidification and single crystal blades must have excellent high temperature properties. A strengthening process was developed to improve high temperature properties of alumina based ceramic cores containing yttria. Besides, different parameters, including reinforcing agent, the number of times of vacuum impregnating, were investigated. The experimental results showed that aqueous yttria sol can improve the high temperature properties of ceramic cores through multiple impregnating, which made it a suitable reinforcing agent. Considering the effects of the strengthening process on the apparent porosity and sintered shrinkage of ceramic cores, the optimal vacuum impregnating process was determined. Furthermore, the strengthening mechanism was revealed by using X-ray diffraction and electron spectroscopy analysis. The high temperature properties of the strengthened ceramic cores can meet the requirements of directional solidification and single crystal casting, which benefits the production of turbine blades.