Several intact or broken stringers attached to an orthotropic sheet with a crack

Several intact or broken stringers which are continuously attached to a cracked orthotropic sheet through an adhesive are considered. The effect of orthotropy on the stress intensity factors is investigated. The stringers are assumed to be partially debonded due to high stress concentrations. The shear stress distribution between the stringers and the plate and the stress intensity factors are obtained from an integral equation which represents the continuity of displacements along the bond lines

A note on a broken layer in an orthotropic laminate composite

An orthotropic laminate composite containing a completely broken layer is considered. The problem is formulated in terms of integral transforms and then reduced to a singular integral equation which is solved numerically. The strength of stress singularity at the crack tip is determined from a characteristic equation which is obtained by studying the dominant part of the singular integral equation near the end points. The stress intensity factors are given for various material properties

A metal sheet stiffened by a partially debonded composite quarter-plate

An isotropic sheet stiffened by means of an orthotropic quarter-plate is considered. The quarter-plate is assumed to be perfectly bonded to the metal sheet everywhere except an area of debonding which may develop due to high stress concentrations. The adhesive which has a small constant thickness is treated as a shear spring. The loads are applied at infinity and supposed to be transmitted through the metal plate. Shear stress distribution between the two plates was obtained from the continuity of displacements along an area where they were bonded to each other

Fracture and contact problems for an elastic wedge

The plane elastostatic contact problem for an infinite elastic wedge of arbitrary angle is discussed. The medium is loaded through a frictionless rigid wedge of a given symmetric profile. Using the Mellin transform formulation the mixed boundary value problem is reduced to a singular integral equation with the contact stress as the unknown function. With the application of the results to the fracture of the medium in mind, the main emphasis in the study has been on the investigation of the singular nature of the stress state around the apex of the wedge and on the determination of the contact pressure

The stress distribution in tempered glass due to a crack

A model describing the failure in tempered glass is proposed and a method of solution is presented. An infinite elastic strip is assumed to represent the glass and the loads vanish everywhere on the boundary as well as at infinity. The problem is solved using the integral equations technique where the input is the residual stresses in the glass

International Transmission of Fiscal Shocks: An Empirical Investigation

This paper investigates how innovations in income taxes and government purchases originating in the U.S. affect the U.S. economy, and how these effects are transmitted to the Canadian economy. Using a semi-structural VAR model and data for both countries for the 1961:1-2004:3 period, we find that fiscal policy innovations originating in the U.S. are transmitted to the Canadian economy by international trade and capital flows through interest rate and exchange rate channels. Unanticipated shocks to U.S. government purchases have beggar thy neighbor effects on Canada. U.S. output increases and Canadian output decreases in response to a positive shock to U.S. government purchases. In response to an unanticipated increase in U.S. income taxes, U.S. output declines while U.S. and Canadian real interest rates rise. The response of Canadian output, however, is not significantly different from zero.

Fiscal Policy and Economic Activity: U.S. Evidence

We investigate the dynamic effects of five different fiscal shocks on the US economy using a structural vector autoregressive (SVAR) model that uses Blanchard-Quah type restrictions. We find that an increase in indirect taxes or in corporate taxes has a contractionary effect on the economy, while an increase in personal taxes is neither contractionary, nor expansionary. These results imply that the Ricardian Equivalence hypothesis holds only for personal taxes. On the spending side, we find that an increase in government wages and salaries has a contractionary effect on the economy, while an increase in defense spending is expansionary. Our results suggest that different fiscal shocks have different and offsetting effects on the economy, and using aggregated data may, therefore, conceal the effects of fiscal policy.

The taxation-growth-nexus revisited

One of the major challenges of empirical tax research is the identification and calculation of appropriate tax data. While there is consensus that average marginal tax rates are most suitable for studying the effects of tax policy on economic growth, due to data limitations the calculation of marginal tax rates has been limited to the U.S. and the U.K. This paper provides calculations of average marginal tax rates for the four Scandinavian countries using the methodologies of Seater [1982, 1985] and Barro and Sahasakul [1983, 1986]. Then, by pooling the newly calculated tax rates for the Scandinavian countries with the data for the U.S. and the U.K., we investigate the effects of tax policy shocks on the per capita GDP growth rate. Our results suggest that an increase in average marginal tax rates has a negative impact on economic growth. Employing Additive Mixed Panel Models with penalized splines as estimation approach, we show that changes in tax rates have nonlinear effects. Increasing average marginal tax rates turn out to be the most distorting at relatively moderate tax rates

Obesity-induced Upper Extremity Lymphedema

Summary: Obesity increases the risk of upper extremity lymphedema following treatment for breast cancer and can cause lower extremity lymphatic dysfunction in extremely obese individuals. We report the first patient with obesity-induced upper extremity lymphedema. A 62-year-old man with a previous body mass index (BMI) of 105.6, presented with a BMI 60.3 following weight loss. He complained of lymphedema of all 4 extremities, which was confirmed by lymphoscintigraphy. Because the upper limbs are more resistant to lymphedema than the lower extremities, a higher BMI threshold may be necessary to cause upper extremity lymphatic dysfunction

Introduction to The Special Issue: Advances in Methods and Measurement in Family Psychology

This special issue presents a collection of reports that highlight recent advances in methods and measurement and also shed light on the complexity of family psychology. The importance of theory in guiding solid family science is evident throughout these reports. The reports include guides for researchers who incorporate direct observation into their research protocols and the ever-expanding field of tele-health interventions. Advanced analytic approaches are offered in the areas of grid sequence analysis, latent fixed-effects models, and the Factors of Curves Model (FOCUS). These sophisticated analytic approaches may be applied to advance systemic thinking in family psychology. The last set of articles illustrate how complex and innovative methodologies are applied to address important societal issues. Work experiences and marital relationships in African American couples address the importance of spillover effects in contemporary families. The creation of biobehavioral plasticity index has the potential to inform gene x environment contributions to family functioning. Finally, the unique methodological issues that are particularly germane to the diverse nature of stepfamilies and nonresident fathers are addressed. We hope that readers of this special issue will return to these reports as resources and examples of theory-driven methods and measurements