bluuebunny/crossref_metadata_2025 huggingface dataset:
Currency Invoicing in Japanese Exports to East Asia: Implications for Yen Internationalization
Authors: Sato Kiyotaka
Published: July 2003

The present paper examines currency invoicing in Japanese exports to East Asia by applying the pricing‐to‐market (PTM) theory. The notable aims of the present paper are to: (i) use a number of sample commodities obtained from the data on monthly series of exports based on the nine‐digit Harmonized System; and (ii) examine currency invoicing practices of Japanese exporters by making a distinction between the long‐run and short‐run PTM under the framework of the error‐correction model. Contrary to the results of previous reports, our study shows that Japanese exporters of electric machinery tend to stabilize US Dollar (USD)‐denominated export prices in the short run in East Asian markets, implying that electric machinery products tend to be invoiced in USD in exports to East Asia. Given the USD‐invoicing practices by Japanese electric machinery exporters, it is hard to expect the further use of the Yen in trade transactions because the electric machinery industry plays a major role in facilitating trade and investment between Japan and East Asia.
China's Exchange Rate Policy: The Case for Greater Flexibility
Authors: Roberts Ivan , Tyers Rod
Published: July 2003

Since the Asian crisis, the merit of the Chinese government's de facto peg to the US Dollar has been the subject of widening debate. This paper reviews the issues surrounding China's currency regime choice and assesses the case for greater fiexibility. Reform era exchange rate policies are examined along with the performance of the economy during and since the Asian crisis. In the Chinese context, the arguments for and against fixed exchange rates are then explained and assessed. Finally, an elemental comparative static macroeconomic model is used to examine the implications of domestic and external shocks under different exchange rate regimes and with differing degrees of capital mobility. The results support the view that more fiexibility would be beneficial to China and that this benefit can be expected to increase as capital mobility increases.
Real Exchange Rate Fluctuations in East Asia: Generalized Impulse‐Response Analysis
Authors: Wang Ping , Dunne Paul
Published: July 2003

Using generalised impulse response analysis, this paper investigates the dynamic adjustment of real exchange rates to real shocks for a group of East Asian currencies. The analysis reveals that the fundamentals, or real factors, explain some, but not all, of the variations of real exchange rates, and that the different disturbances have different degrees of importance for each currency. Therefore, there is no universal panacea for fluctuations in real exchange rates. The findings leave considerable scope for policy intervention to mitigate the unfavourable effects.
Innovation and Market Value in Newly‐Industrialized Countries: The Case of Taiwanese Electronics Firms
Authors: Yang Chih‐Hai , Chen Jong‐Rong
Published: July 2003

The relationship between patents, research and development (R&D), and market value in newly industrialized countries is examined for a panel data of Taiwanese electronics firms. Empirical results show that the market value of electronics firms is strongly related to patent count and R&D expenditure in Taiwan. Controlling potential heterogeneity of patents and allowing the value of Tobin's q to vary across firms, the estimated results are quite consistent, which is encouraging for Taiwan's government as it has implemented many policies encouraging firms to commit to R&D. In addition, the significant and positive impact of the sales growth rate might refiect the expectation feature of the stock market.
Do Committees Ru(i)n the Bio‐Political Culture? On the Democratic Legitimacy of Bioethics Committees
Authors: Friele Minou Bernadette
Published: July 2003

Bioethical and bio‐political questions are increasingly tackled by committees, councils, and other advisory boards that work on different and often interrelated levels. Research ethics committees work on an institutional or clinical level; local advisory boards deal with biomedical topics on the level of particular political regions; national and international political advisory boards try to answer questions about morally problematic political decisions in medical research and practice. In accordance with the increasing number and importance of committees, the quality of their work and their functional status are being subjected to more and more scrutiny. Besides overall criticism regarding the quality of their work, particular committees giving political advice are often suspected of being incompatible with democratic values, such as respect for affected parties, representation of diverse values and transparency in the decision‐making processes. Based on the example of the German National Ethics Council, whose inauguration caused a still ongoing debate on the aims and scopes of committees in general, this paper discusses: (1) the requirements of modern democratic societies in dealing with complex scientific‐technical problems; (2) the composition and organisation of committees working as political advisory boards; and (3) the appointment procedures and roles of laymen and experts, and here in particular of ethicists, who may legitimately be taken on by a committee.

I will argue that bioethics committees do not necessarily endanger democratic values, but can considerably improve their realisation in democratic decision‐making procedures – if, and only if, they do not act as substitutes for parliamentarian processes, but help prepare parliamentarian processes to be organised as rationally as possible.
Should Consensus Be ‘The Commission Method’ in the US? The Perspective of the Federal Advisory Committee Act, Regulations, and Case Law
Authors: Spielman Bethany
Published: July 2003

This paper examines the drive for consensus from the perspective of the good government framework for federal advisory commissions in the United States. Specifically, the paper examines the Federal Advisory Committee Act (FACA) – the statute, its regulations, and case law. It shows that the FACA was intended to be an antidote to abuses in consensus‐making processes, including the failure to fully include competing views on commissions. The index of suspicion in the FACA scheme rises when a group work product – including a consensus report – is to be the basis of recommendations to federal officials. Once FACA's requirements regarding committee composition are satisfied, the index of suspicion drops and FACA is indifferent to consensus‐making; but the conditions for informed, meaningful participation apply to members who dissent from, as well as those who participate in, consensus. In negotiated rulemaking, the push for consensus and closure creates unacceptable tension with the good government goals of openness and accountability. Proponents of consensus‐only bioethics commissions can learn from FACA‐related legislative, agency, and judicial insights that consensus‐seeking is not always desired by government officials; is rarely cost free; and that diversity and dissent enhance openness, accountability, and fairness. The burden of proof is therefore on proponents of a consensus‐only standard for bioethics commissions to demonstrate that a drive for consensus furthers sound decision‐making by government officials more than it sets back openness and accountability to a diverse public.
The Role of National Ethics Commissions in Finland
Authors: Halila Ritva
Published: July 2003

There are six national ethics commissions in Finland. The National Advisory Board on Research Ethics was first established in 1991, followed by the National Advisory Board on Biotechnology and the Board on Gene Technology in 1995. The National Advisory Board on Health Care Ethics was established in 1998, followed by its Sub‐Committee on Medical Research Ethics in 1999. The Co‐operation Group for Laboratory Animal Sciences was established in 2001. Only the Board on Gene Technology works as a national authority and gives binding opinions and recommendations about the use of genetically modified organisms. The Sub‐Committee on Medical Research Ethics acts as a national research ethics committee and gives opinions about research projects. Other advisory boards do not make legally binding decisions, but their expertise gives a lot of power to their opinions and statements.

The commissions work in close collaboration with each other, having regular meetings. They arrange seminars and conferences, and share information with each other. The commissions also share duties and information in international collaboration.

How the voice and opinions of these commissions is heard in society lies in the wide, multi‐professional expertise of their members. Large commissions and wide expertise may make it difficult to find consensus in their opinions and statements, although wide expertise may, more than discussion in a small expert group, help to further process difficult ethical issues.

Collaboration between different bodies is important in order to share duties, and also to add more emphasis to the statements and opinions where different bodies share interests. In our country, the interest that national commissions share is research ethics, where the advisory boards and their members have discharged collaborative activities for years.
Multilateral, Regional and Bilateral Trade‐Policy Options for the United States and Japan
Authors: Brown Drusilla K. , Deardorff Alan V. , Stern Robert M.
Published: July 2003

We have used the Michigan Model of World Production and Trade to simulate the economic effects on the United States, Japan, and other major trading countries/regions of the Doha Round of WTO multilateral trade negotiations and a variety of regional/bilateral free trade agreements (FTAs) involving the United States and Japan. We estimate that an assumed reduction of post‐Uruguay Round tariffs and other barriers on agricultural and industrial products and services by 33 per cent in the Doha Round would increase world welfare by $686.4 billion, with gains of $164.0 billion for the United States, $132.6 billion for Japan, and significant gains for all other industrialised and developing countries/regions. If there were global free trade with all post‐Uruguay Round trade barriers completely removed, world welfare would increase by $2.1 trillion, with gains of $497.0 billion (5.5 per cent of GNP) for the United States and $401.9 billion (6.2 per cent of GNP) for Japan. Regional agreements such as an APEC FTA, an ASEAN Plus 3 FTA, and a Western Hemisphere FTA would increase global and member country welfare but much less so than the Doha multilateral trade round would. Separate bilateral FTAs involving Japan with Singapore, Mexico, Chile and Korea, and the United States with Chile, Singapore and Korea would have positive, though generally small, welfare effects on the partner countries, but potentially disruptive sectoral employment shifts in some countries. There would be trade diversion and detrimental welfare effects on some non‐member countries for both the regional and bilateral FTAs analysed. The welfare gains from multilateral trade liberalisation are therefore considerably greater than the gains from preferential trading arrangements and more uniformly positive for all countries.
The Africa Growth and Opportunity Act and its Rules of Origin: Generosity Undermined?
Authors: Mattoo Aaditya , Roy Devesh , Subramanian Arvind
Published: July 2003

This paper describes the United States recently enacted Africa Growth and Opportunity Act (AGOA) and assesses its quantitative impact on African exports. The AGOA expands the scope of preferential access of Africa's exports to the United States in key areas such as clothing. However, its medium‐term benefits – estimated at about US$100‐$140 million, an 8−11 per cent addition to current non‐oil exports – would have been nearly five times greater (US$540 million) if no restrictive conditions had been imposed on the terms of market access. The most important of these conditions are the rules of origin with which African exporters of clothing must comply to benefit from duty‐free access.
Possible Dynamic Effects of AFTA for the New Member Countries
Authors: Fukase Emiko , Winters L. Alan
Published: July 2003

We discuss the possibledynamicbenefits of economic integration for the new members of ASEAN. Direct evidence on regional integration and growth is weak, but three indirect channels are possible. Openness increases access to foreign knowledge, which could help productivity growth. Trade liberalisation is likely to stimulate investment and might promote the integration of the regional production network. Binding liberalisation under AFTA would help ‘lock‐in’ and accelerate liberal economic reforms. These gains are not automatic, however. Discriminatory liberalisation will switch imports from sources with high stocks of knowledge towards ASEAN countries, which have lower stocks, and so may lower productivity growth. We term this ‘dynamic’ trade diversion. In addition, local absorptive capabilities must be developed to benefit fully from technology transfer. Finally, we recommend extending AFTA commitments on an MFN basis in order to avoid static and dynamic trade diversions.
Wage Inequality in the United Kingdom: Trade and/or Technology?
Authors: De Santis Roberto A.
Published: July 2003

I employ two alternative intra‐industry trade Applied General Equilibrium (AGE) models to explain some stylised facts of the British economy. The model with skill‐biased technical change (i.e. exogenous skill‐biased technical change à la Solow) can explain the rise in wage inequality between skilled and unskilled workers, the decline in manufacturing and the expansion of modern services. However, the model where technical change is trade‐induced (i.e. endogenous sector‐biased technical change à la Romer) performs better, because it can also explain the exponential rise of imported intermediate capital goods and developments in the wage rate of unskilled workers.
Testing of Fractional Cointegration in Macroeconomic Time Series*
Authors: Gil‐Alana Luis A.
Published: July 2003

We propose in this article a two‐step testing procedure of fractional cointegration in macroeconomic time series. It is based on Robinson's (Journal of the American Statistical Association, Vol. 89, p. 1420) univariate tests and is similar in spirit to the one proposed by Engle & Granger (Econometrica, Vol. 55, p. 251), testing initially the order of integration of the individual series and then, testing the degree of integration of the residuals from the cointegrating relationship. Finite‐sample critical values of the new tests are computed and Monte Carlo experiments are conducted to examine the size and the power properties of the tests in finite samples. An empirical application, using the same datasets as in Engle & Granger (Econometrica, Vol. 55, p. 251) and Campbell & Shiller (Journal of Political Economy, Vol. 95, p. 1062), is also carried out at the end of the article.
A Natural Experiment on the ‘Race to the Bottom’ Hypothesis: Testing for Stochastic Dominance in Temporal Pollution Trends*
Authors: Millimet Daniel L. , List John A.
Published: July 2003

Devolution of tasks to local levels of government has recently become a popular agenda item within certain political factions in the US. While one expects the local policymaker to tailor policies to match the preferences of his constituents, critics of local policymaking claim that externalities are ignored and inefficiencies thus arise under local control of certain policies. A primary example concerns the control of pollution, which is known to have adverse effects on neighbouring jurisdictions. Whether localities actually ‘race to the bottom’ and enact lax environmental policies when given the chance remains an open issue. In this study, we make use of stochastic dominance tests to examine if President Reagan's policy of ‘New Federalism’ in the early 1980s induced states to lower environmental standards. Among the several environmental measures analysed, we do not find any evidence that the ‘race to the bottom’ materialized. Indeed, the evidence shows that even during these lean years of federal intervention several indicators of environmental quality at the state level continued to improve.
Okun's Law Revisited*
Authors: Cuaresma Jesús Crespo
Published: July 2003

In the light of modern theoretical studies, the negative relationship between output and unemployment may take a nonlinear form, in the sense that changes in output can cause asymmetric changes in the unemployment rate. A regime‐dependent specification of Okun's law, where the inverse relationship between cyclical unemployment and cyclical GDP is allowed to differ across recessions and expansions, is estimated for the US economy. Using both the Hodrick–Prescott filter and a bivariate structural time series model to isolate the cyclical component of the variables of interest, the nonlinear specification is highly significant when tested against the linear alternative independently of the method used for extracting the cycle of unemployment and GDP. The estimation results imply that the contemporaneous effect of growth on unemployment is asymmetric and significantly higher in recessions than in expansions, and shocks to unemployment tend to be more persistent in the expansionary regime.
Economic Integration and Regional Business Cycles: Evidence from the Iberian Regions*
Authors: Barrios Salvador , de Lucio Juan José
Published: July 2003

This paper provides evidence of the positive impact of economic integration on EU regions’ business cycles convergence by focusing on two neighbouring countries: Spain and Portugal. We show that while a rise in cross‐country business cycle correlation has also been experienced by other European countries, it has been relatively more pronounced for Iberian regions. Econometric evidence suggests that the existence of an administrative border, the economic size of regions and their industrial structures can explain a substantial proportion of regional cycles.
Why so only 5.5% of Black Men Marry White Women?*
Authors: Wong Linda Y.
Published: July 2003

Only 5.5% of black males married white females in 1990, and the family‐income premium for intermarried black males was 7%. This article estimates the impact of the mating taboo, courting opportunities, and individual endowments on the black male marriage market. Results indicate that eliminating the mating taboo would raise the intermarriage rate from 5.5 to 64%, and do away with the intermarriage premium. Improving black males' endowments or allowing black males to meet white females as frequently as they do black females would not increase intermarriage.
More on Marriage, Fertility, and the Distribution of Income*
Authors: Greenwood Jeremy , Guner Nezih , Knowles John A.
Published: July 2003

According to Pareto (1896), the distribution of income depends on “the nature of the people comprising a society, on the organization of the latter, and, also, in part, on chance.” In the model developed here the “nature of the people” is captured by attitudes toward marriage, divorce, fertility, and children. Singles search for mates in a marriage market. Married agents bargain about work, and the quantity and quality of children. They can divorce. Social policies, such as child support requirements, reflect the “organization of the (society).” Finally, “chance” is modeled by randomness in income, marriage opportunities, and marital bliss.
Unemployment insurance and the business cycle*
Authors: Brown Laura , Ferrall Christopher
Published: July 2003

An equilibrium model is developed to study the interaction of the business cycle, unemployment insurance (UI), and the labor market for young men in Canada. The model combines optimal job offer, layoff, and recall decisions within a numerically solved and restricted Bayesian–Nash equilibrium. We consider the long‐run implications of changes made to unemployment insurance in Canada during the 1990s. The changes lead to equilibrium increases in average rates of unemployment, layoffs, and recalls. Eliminating UI lowers the equilibrium unemployment rate and average observed earnings. UI policy affects the timing of cycles of endogenous outcomes relative to the productivity cycle.
Decomposing Lorenz and Concentration Curves*
Authors: Bishop John A. , Chow K. Victor , Zeager Lester A.
Published: July 2003

We decompose the Lorenz curve (LC) and its associated concentration curve (CC) by population subgroups. To illustrate these decompositions, we examine changes in earnings inequality among West Germans, East Germans, and foreign guest workers during the recent German unification. We show that East German earnings have become less concentrated in the lower deciles of the overall German earnings distribution, whereas the earnings of West Germans and foreign guest workers have become more concentrated in the lower deciles.
Rotating Savings and Credit Associations When Participants are Risk Averse*
Authors: Klonner Stefan
Published: July 2003

We model rotating savings and credit associations (Roscas) among risk‐averse participants who experience privately observed income shocks. A random Rosca is not advantageous, whereas a bidding Rosca is if temporal risk aversion is less pronounced than static risk aversion. The payoff scheme of a bidding Rosca facilitates risk sharing in the presence of information asymmetries. The risk‐sharing performance of a simple arrangement where a group of homogenous individuals runs several bidding Roscas simultaneously is as good as that of a linear risk‐sharing contract, and is more enforceable because it carries a fixed rather than a variable contribution.
Compensations as signaling devices in the political economy of reforms*
Authors: Castro Rui , Coen‐Pirani Daniele
Published: July 2003

We propose an explanation for why efficient reforms are not carried out when losers can block their implementation and compensations are feasible. In our model, a government tries to sequentially implement two efficient reforms by bargaining with interest groups. The organization of interest groups is endogenous. Compensations are distortionary and different governments care differently about distortions. Governments use low compensations to discourage losers who just want to receive transfers from organizing. This comes at the cost of reforms being blocked by interest groups with relatively high losses, resulting in a bias against payment of compensations and the implementation of reforms.
Trade restrictiveness and efficiency*
Authors: Chau Nancy H. , Färe Rolf , Grosskopf Shawna
Published: July 2003

This article proposes a trade restrictiveness quantity index (TRQI) to measure the welfare impact of trade restrictions based on a distance functions approach. The TRQI embodies two Farrell measures of efficiency—respectively for producers and consumers—that can be computed using standard efficiency measurement techniques. The TRQI can also be decomposed into a trade distortion and domestic distortion component. In the context of the debate on the interlinkages between openness and economic performance, the TRQI offers a means to disentangle economic inefficiencies induced by trade restrictions alone, from otherwise not directly trade‐related economic inefficiencies induced by domestic distortions.
Commons with increasing marginal costs: random priority versus average cost*
Authors: Crès Hervé , Moulin Hervé
Published: July 2003

Indivisible units are produced with increasing marginal costs. Under average cost, each user pays average cost. Under random priority, users are randomly ordered (without bias) and successively offered to buy at the true marginal cost. Both average cost (AC) and random priority (RP) inefficiently overproduce. RP tends to overproduce less, but which game collects more surplus depends much on the demand configuration. We show that a key to compare the welfare properties of the two mechanisms is the crowding factor, i.e., the number of potential users over the number of units of output users can afford: The more crowded the commons, the more RP outperforms AC. In the quadratic cost case, beyond the threshold value of 2.4 for the crowding factor, RP strongly outperforms AC; beneath it AC only mildly outperforms RP. Thus the RP mechanism manages crowded commons better than AC.
Multiunit Pay‐Your‐Bid Auction with One‐Dimensional Multiunit Demands*
Authors: Lebrun Bernard , Tremblay Marie‐Christine
Published: July 2003

An arbitrary number of units of a good is sold to two bidders through a discriminatory auction. The bidders are homogeneous ex ante and their demand functions are two‐step functions that depend on a single parameter. We characterize the symmetric Bayesian equilibrium and prove its existence and uniqueness. We compare this equilibrium with the equilibrium of the multiunit Vickrey auction and with the equilibria of the single‐unit first price and second price auctions. We examine the consequences of bundling all units into one package. We study the impacts that variations of the “relative” supply have on the equilibrium, on the bidders' average payoffs per unit, and on the efficiency of the equilibrium allocation.
To Trade Or Not To Trade: Economies With A Variable Number Of Tradeables*
Authors: Gilles Robert P. , Diamantaras Dimitrios
Published: July 2003

We present a general equilibrium model that encompasses the endogenous selection and shadow‐pricing of a set of tradeable commodities, with home‐based and social production activities. In the model, a market system is a set of costly social institutions which embody the trade and production technologies available in the economy. Our equilibrium concept describes the pricing of market institutions, thus pricing the tradeability of a commodity. We obtain the existence and the decentralization of Pareto‐efficient allocations. We discuss an example regarding the transition of a guild‐based economy into a market‐based economy.
Advertising, learning, and consumer choice in experience good markets: an empirical examination*
Authors: Ackerberg Daniel A.
Published: July 2003

This article empirically analyzes different effects of advertising in a nondurable, experience good market. A dynamic learning model of consumer behavior is presented in which I allow both “informative” effects of advertising and “prestige” or “image” effects of advertising. This learning model is estimated using consumer level panel data tracking grocery purchases and advertising exposures over time. Empirical results suggest that in this market, advertising's primary effect was that of informing consumers. The estimates are used to quantify the value of this information to consumers and evaluate the welfare implications of an alternative advertising regulatory regime.
Sheet Metal Forming Using Polymer Composite Rapid Prototype Tooling
Authors: Park Y. , Colton J. S.
Published: July 2003

To meet the growing demand for rapid, low-cost die fabrication technology in the sheet metal forming industry, easy-to-machine, polyurethane-based, composite board stock is widely used as a rapid tooling material. However, the failure mechanisms of the rapid prototyped tools are not clearly understood, thus making the prediction of tool life difficult. As a fundamental step for effective tool life estimation, the microstructure and the mechanical properties of the polymer composite tooling material were characterized. A finite element model of 90° V-die bending process was developed, and the effects of process parameters on stress distribution in punch and die were investigated through simulation. The simulation results were verified through experiments using instrumented, laboratory-scale punch and die sets.
Estimation of Steady-State Creep Behavior of Al2O3/YAG Eutectic Composite by Image-Based Finite Element Analysis
Authors: Miyazaki Noriyuki , Ikeda Toru , Komura Toshihiro
Published: July 2003

Al 2 O 3 / YAG eutectic composite has been developed for a structural material used in ultra high temperature environments over 1500°C such as a gasturbine. Creep behavior is one of the important material properties in ultra high temperature materials. In the present study, we propose an image-based finite element analysis for estimating the steady state creep behavior of the Al2O3/YAG eutectic composite. In the image-based finite element analysis, microstructure of the material taken by a SEM is modeled into a finite element mesh using a software for image process. Then finite element creep analyses are carried out to obtain the steady state creep behavior of the Al2O3/YAG eutectic composite by using steady state creep constitutive equations for both Al2O3 single crystal and YAG single crystal. The results of steady state creep behavior obtained from the image-based finite element analysis are compared with the experimental results. It is found that the steady state creep behavior of the Al2O3/YAG eutectic composite is accurately estimated by the image-based finite element analysis. Furthermore, we examine the effect of volume fractions of the constituents on the steady state creep behavior of the Al2O3/YAG eutectic composite.
Measurement of Thickness-Average Residual Stress Near the Edge of a Thin Laser Peened Strip
Authors: Rankin Jon E. , Hill Michael R.
Published: July 2003

This paper presents measurements of the thickness-average residual stress imposed by laser peening near the edge of a thin sheet of a common titanium alloy. The slitting (or crack compliance) method was extended beyond its typical form to make residual stress measurements in this geometry. An analytical method was employed to optimize the experiment design for the near-edge, thin material geometry, where the design included the optimal number and position of strain gages and the most effective set of basis functions for stress computation. Two experiments were performed on a titanium strip that had been laser peened near the edge, using an optimal experiment design. Residual stress was found to be large and compressive near the edge of the sheet, with the compressive stress extending over 38% of the laser peened area.
Finite Element Modeling of Superplastic Sheet Metal Forming for Cavity Sensitive Materials
Authors: Liew K. M. , Tan H. , Tan M. J.
Published: July 2003

In this paper, a constitutive equation for superplasticity, which is based on the microstructural mechanism of superplastic deformation taking into account the effects of deformation damage, is incorporated into the finite element method to simulate the superplastic forming process. The effects of strain rate sensitivity, cavity growth and imposed hydrostatic pressure on the strain limit are studied. The predicted results are validated through the comparison with the existing experimental data. It is found that the present model produces accurate results in all cases.
One-Dimensional Dynamic Compressive Behavior of EPDM Rubber
Authors: Song B. , Chen W.
Published: July 2003

Dynamic compressive stress-strain curves at various strain rates of an Ethylene-Propylene-Diene Monomer Copolymer (EPDM) rubber have been determined with a modified split Hopkinson pressure bar (SHPB). The use of a pulse-shaping technique ensures that the specimen deforms at a nearly constant strain rate under dynamically equilibrated stress. The validity of the experiments was monitored by a high-speed digital camera for specimen edge deformation, and by piezoelectric force transducers for dynamic stress equilibrium. The resulting dynamic stress-strain curves for the EPDM indicate that the material is sensitive to strain rates and that the strain-rate sensitivity depends on the value of strain. Based on a strain energy function theory, a one-dimensional dynamic constitutive equation for this rubber was modified to describe the high strain-rate experimental results within the ranges of strain and strain rates presented in this paper.
The Computation and Measurement of Residual Stresses in Laser Deposited Layers
Authors: Finnie S. , Cheng W. , Finnie I. , Drezet J. M. , Gremaud M.
Published: July 2003

Laser metal forming is an attractive process for rapid prototyping or the rebuilding of worn parts. However, large tensile stress may arise in layers deposited by laser melting of powder. A potential solution is to preheat the substrate before and during deposition of layers to introduce sufficient contraction during cooling in the substrate to modify the residual stress distribution in the deposited layers. To demonstrate the value of this approach, specimens were prepared by depositing stellite F on a stainless steel substrate with and without preheating. Residual stresses were computed by numerical simulation and measured using the crack compliance method. For non-preheated specimens simulation and experiment agreed well and showed that extremely high residual tensile stresses were present in the laser melted material. By contrast, pre-heated specimens show high compressive stresses in the clad material. However, in this case the numerical simulation and experimental measurement showed very different stress distribution. This is attributed to out of plane deformation due to the high compressive stresses which are not permitted in the numerical simulation. A “strength of materials” analysis of the effect of out of plane deformation was used to correct the simulation, Agreement with experimental results was then satisfactory.
Mechanical Characterization of a CVD Diamond Coating by Nanoindentation Test
Authors: Bruno L. , Furgiuele F. M. , Sciume´ G.
Published: July 2003

A FEM analysis was carried out to study the mechanical behavior of a hard coating subjected to a nanoindentation test performed with a Berkovich indenter. The nanoindentation test was simulated by FEM code MSC Marc. The case study is a coating of CVD (Chemical Vapor Deposition) diamond. By the simulation it is possible to obtain the load-displacement curve by which Young modulus and hardness may be evaluated. The paper also analyzes the residual stresses developed at the end of the unloading phase and the influence of the strengthening law to determine the hardness and the elastic modulus of the CVD diamond. The analysis has demonstrated, by the comparison with the experimental results, that the numerical model well describes the behavior of the coating of CVD diamond in the nanoindentation test; in addition it was pointed out that the choice of the hardening law is a crucial aspect in the simulation.
Finite Element Modeling of Chip Formation in the Domain of Negative Rake Angle Cutting
Authors: Ohbuchi Y. , Obikawa T.
Published: July 2003

A thermo-elastic-plastic finite element modeling of orthogonal cutting with a large negative rake angle has been developed to understand the mechanism and thermal aspects of grinding. A stagnant chip material ahead of the tool tip, which is always observed with large negative rake angles, is assumed to act like a stable built-up edge. Serrated chips, one of typical shapes of chips observed in single grain grinding experiment, form when analyzing the machining of 0.93%C carbon steel SK-5 with a rake angle of minus forty five or minus sixty degrees. There appear high and low temperature zones alternately according to severe and mild shear in the primary shear zone respectively. The shapes of chips depend strongly on the cutting speed and undeformed chip thickness; as the cutting speed or the undeformed chip thickness decreases, chip shape changes from a serrated type to a bulging one to a wavy or flow type. Therefore, there exists the critical cutting speed over which a chip can form and flow along a rake face for a given large negative rake angle and undeformed chip thickness.
Adhesion and friction studies of microelectromechanical systems/nanoelectromechanical systems materials using a novel microtriboapparatus
Authors: Liu Huiwen , Bhushan Bharat
Published: July 2003

Adhesion and friction impacts the reliability of microelectromechanical systems/nanoelectromechanical systems (MEMS/NEMS) devices. It is essential to study the adhesion and friction properties of the materials that are commonly used in these devices. A novel microtriboapparatus, capable of adopting MEMS components, has been used to perform tribological studies. Calibration of sensors, piezos, and cantilever was performed in this study. The adhesion and friction properties of single-crystal silicon, diamondlike carbon (DLC) films, and hexadecane thiol (HDT) self-assembled monolayers were investigated, and the effect of rest time, velocity, relative humidity, and temperature was studied. The relevant adhesion and friction mechanisms are also discussed. It is found that solid films of DLC and HDT can apparently reduce the adhesion and friction of Si(100). In the case of Si(100), rest time, velocity, relative humidity, and temperature dependence is found, whereas DLC and HDT are insensitive or less sensitive to these parameters. This study suggests that DLC and HDT films can be used as antiadhesion coatings for MEMS/NEMS at different environments and operating conditions.
Nanoscale oxidation of zirconium surfaces: Kinetics and mechanisms
Authors: Farkas N. , Zhang G. , Evans E. A. , Ramsier R. D. , Dagata J. A.
Published: July 2003

We show that atomic force microscope-induced oxide features can be formed reproducibly on both Zr and ZrN surfaces, and that the growth rate decreases rapidly with increasing time. There is an increase in oxide-feature height with humidity for both systems, and an approximately linear dependence of the height of the structures on the applied voltage for all films for short exposure times. As the anodization time increases, only the thinnest (6 nm) films show a large enhancement in oxide-feature height, demonstrating the role of the film/substrate interface. Under the same conditions, the height of features grown on ZrN films is greater than for those grown on Zr films, indicating that nitrogen plays a role in the oxidation process.
Analysis of stresses in Ru thin films prepared by chemical vapor deposition
Authors: Lim Ha Jin , Kang Sang Yeol , Hwang Cheol Seong , Kim Hyeong Joon
Published: July 2003

Ru is the most promising material for the capacitor electrode in the next generation dynamic random access memories. Ru thin films, however, which are deposited by chemical vapor deposition (CVD) have high tensile stresses. Therefore, many problems with respect to device reliability such as peeling or thermal deformation have been reported. In this study, we investigated the effects of the various deposition parameters on the stress behaviors. Ru thin films were prepared by metal-organic CVD on (100) Si substrate using RuCp(i-PrCp) precursor and O2 reaction gas. Internal stress of Ru thin film was measured using the laser scanning method. As the Ru film grew, tensile stress increased. And the tensile stress also increased with reduction of substrate temperature. These tendencies are attributed to low atomic mobility of the Ru material (Tm=2523 K). In addition, tensile stress increased more than 300 MPa after the annealing process. It can be explained by densification through rearrangement of Ru atoms during annealing. Based on these results, we examined the origins of this stress generation with quantitative analysis. Then the experiments to reduce these stresses were performed by control of the deposition rate. Under the lower deposition rate, the film became a denser structure and this led the tensile stress, reducing successfully down to about 180 MPa from 560 MPa.
Metallization schemes for radio frequency microelectromechanical system switches
Authors: Leedy K. D. , Cortez R. , Ebel J. L. , Strawser R. E. , Walker A. P. , DeSalvo G. C. , Young R. M.
Published: July 2003

A series of surface micromachined microelectromechanical system switches with composite metal beams were fabricated by standard photolithographic techniques. The study was conducted in order to assess the influence of film stress and composition on the released shape of cantilever and fixed-fixed beam structures. A 1 μm thick evaporated Au film was the basis for all bridge materials with additional 20 nm layers of evaporated or sputter deposited Ti, Pt, W, or Au on the top or bottom surface of the thick Au. The planarity and stress gradient of cantilever beam structures and the planarity of fixed-fixed beam structures were measured by optical interferometry. Gold-only bridge structures displayed the best planarity of those examined while structures with Ti layers displayed the least planarity. Cantilever stress gradients calculated using both cantilever-tip deflection and radius of curvature techniques were typically between 9 and 16 MPa/μm. The thin film biaxial moduli used in stress gradient calculations were measured using a wafer curvature technique and were slightly higher than the bulk Au value. Results of this study show that thin metal layers (2%–6% of total beam thickness) have substantial influence on released beam curvatures but that beam planarity can be achieved with a suitable combination of materials.
Role of carbon in boron suboxide thin films
Authors: Music Denis , Kugler Veronika M. , Czigány Zsolt , Flink Axel , Werner Oskar , Schneider Jochen M. , Hultman Lars , Helmersson Ulf
Published: July 2003

Boron suboxide thin films, with controlled carbon content, were grown by rf dual magnetron sputtering of boron and carbon targets in an argon–oxygen atmosphere. Film composition, structure, mechanical, and electrical properties were evaluated with x-ray photoelectron spectroscopy, Auger electron spectroscopy, x-ray diffraction, transmission electron microscopy, nanoindentation, and high-frequency capacitance–voltage measurements. X-ray amorphous B–O–C films (O/B=0.02) showed an increase in density from 2.0 to 2.4 g/cm3 as C content was increased from 0 to 0.6 at. % and the film with the highest density had nanocrystalline inclusions. The density increase occurred most likely due to the formation of B–C bonds, which are shorter than B–B bonds. All measured material properties were found to depend strongly on the C content and thus film density. The elastic modulus increased from 188 to 281 GPa with the increasing C content, while the relative dielectric constant decreased from 19.2 to 0.9. Hence, B–O–C films show a potential for protective coatings and even for application in electronic and optical devices.
Surface electronic structure of a vicinal Cu crystal
Authors: Lobo J. , Michel E. G. , Bachmann A. R. , Speller S. , Roca L. , Kuntze J. , Ortega J. E.
Published: July 2003

The surface of a 12° vicinal Cu(111) crystal is formed by a regular distribution of (111) terraces, giving rise to a well-ordered step superlattice. Angle-resolved photoemission experiments show that the modulation plane of the Cu(111) surface state is the optical mean surface. The surface state is observed at the edge of the surface Brillouin zone regularly repeated with the superlattice periodicity. The intensity distribution of the surface state in the reciprocal space has been probed using different photon energies. The results can be well understood on the basis of a simple diffraction-like model involving the bulk band properties.
Adsorption and reaction of NO on oxidized and reduced SrTiO3(100) surfaces
Authors: Azad S. , Szanyi J. , Peden C. H. F. , Wang L.-Q.
Published: July 2003

Adsorption and reaction of NO on oxidized and reduced SrTiO3(100) surfaces have been studied using temperature programmed desorption (TPD). Major desorption peaks for NO from the fully oxidized surface are found at 140 and 260 K, along with a long tail that continues up to 500 K. The desorption features at 140 and 260 K correspond to activation energies of 36 and 66 kJ/mol, respectively, using a simple Redhead analysis. NO reacts nondissociatively on the fully oxidized surface. Reactivity of reduced SrTiO3(100) is relatively higher than that of the fully oxidized surface and is influenced by the adsorption temperature of the NO molecules on the surface. NO and N2O are the major desorption products following adsorption of NO on the reduced surface at 110 K. Desorption of N2O from significantly reduced SrTiO3(100) indicates that the oxygen atoms of the adsorbed NO molecules are preferentially extracted by the surface oxygen vacancy sites, whereas the surface oxidizes as a result of the deoxygenation of the adsorbates. Adsorption of NO on the reduced surface at 297 K is followed by breakage of the N–O bond producing adsorbed N and O atoms and recombination of these adspecies results in desorption of NO and N2 from this surface. Adsorption of NO on the significantly reduced surface at 200 K is followed by desorption of NO, N2, and N2O as TPD products and the reactivity of this surface at 200 K presumably is a composite of the behavior observed for NO adsorption at 110 and 297 K.
Oxygen adsorption on Cu–9 at. %Al(111) studied by low energy electron diffraction and Auger electron spectroscopy
Authors: Yoshitake Michiko , Bera Santanu , Yamauchi Yasuhiro , Song Weijie
Published: July 2003

Cu-based alloys have been used for electric cables for long time. In the field of microelectronics, Al had been used for electrical wiring. However, it became clear that electromigration occurs in Al that causes breaking of wires in minute wirings. Due to this problem, Cu wiring is used in most advanced microprocessors. Cu metal is more corrosive than Al and Cu-based alloys with a small amount of Al is expected to solve problems both on electromigration and corrosion. The initial stage of corrosion is oxygen adsorption. We studied surface segregation of Al on Cu–9% Al(111) and oxygen adsorption on the surface with/without Al segregation in ultrahigh vacuum by low energy electron diffraction (LEED) and Auger electron spectroscopy. It was found that Al segregates on the surface to form (∛×∛)R30° structure and the structure vanishes above 595 K to give (1×1) structure while Al still segregates. The specimen was exposed to oxygen at different temperatures. The amount of oxygen uptake was not structure dependent but temperature dependent. Below 595 K, only a small amount of oxygen adsorbed. Between 595 and 870 K, oxygen adsorbed surface showed amorphous LEED pattern. The specimen was annealed at 1070 K after oxygen exposure. When the specimen was exposed oxygen below 870 K, the oxygen Auger intensity decreased significantly by annealing and the annealed surface showed (∛×∛)R30° structure at room temperature. When the specimen was exposed to oxygen at 870 K, diffused spots developed newly in LEED pattern but the pattern disappeared after 1070 K annealing while oxygen Auger intensity remained almost constant. Exposing the specimen to oxygen at 995 K resulted in clear spots in the LEED pattern, which were attributed to the (7/∛×7∛)R30° structure.