Reply to Comments of P. W. Smith, Jr.

In his comments on this subject, Smith has put emphasis on the special nature of the plane-wave solution in acoustic problems. It is perhaps unnecessary to defend the importance of the plane-wave solution in a linear theory

The Influence of Mediterranean Modernist Movement of Architecture in Lefkoşa: the First and Early Second Half of 20th Century

The twentieth century modern architectures in Lefkosia in North Cyprus are changing especially in residential building. This change is occurs based on the client\u27s orders or because of the dilapidated condition of the buildings. Identify the characteristics of modernist architectural movement will help in identifying these buildings and recognize the changes applied on them. The paper aims to reach the rationale understanding about the norms of modern architecture in Lefkoşa in the twentieth century. The methodology is based on analyzing the residential buildings designed by local architects and “Ahmet Vural Bahaeddin” selected as one of the famous modernist architect in the twentieth century in North Cyprus. Residential buildings from Milan and Rome in Italy, as well as Baecelina in Spain selected for analysis. The paper tries to demonstrate the presence of vernacular elements in modern architecture in Lefkoşa. Two vernacular elements were studied, i) the patio (outside and inside interrelation), and ii) the façade materials (exposed stone) as vernacular elements in “Mediterranean modernist architecture”. The paper delineated the influence of the “Mediterranean modernist movement” on modern architecture in Lefkoşa in the 20th century. The findings show that there is influence by Modernist movement of architecture in other Mediterranean cities in Italy and Espain on the modern architecture in Lefkoşa. The results contribute evidence to promote our understanding regarding the modernist architecture in Lefkoşa

Experimental and analytical investigation of the fracture processes of boron/aluminum laminates containing notches

Experimental results for five laminate orientations of boron/aluminum composites containing either circular holes or crack-like slits are presented. Specimen stress-strain behavior, stress at first fiber failure, and ultimate strength were determined. Radiographs were used to monitor the fracture process. The specimens were analyzed with a three-dimensional elastic-elastic finite-element model. The first fiber failures in notched specimens with laminate orientation occurred at or very near the specimen ultimate strength. For notched unidirectional specimens, the first fiber failure occurred at approximately one-half of the specimen ultimate strength. Acoustic emission events correlated with fiber breaks in unidirectional composites, but did not for other laminates. Circular holes and crack-like slits of the same characteristic length were found to produce approximately the same strength reduction. The predicted stress-strain responses and stress at first fiber failure compared very well with test data for laminates containing 0 deg fibers

Sea Level Variation Along the Western Coast of the Arabian Gulf

Observed hourly tidal heights from six stations during the period 1980-1987 were used in the analyses. Daily readings of the pressure at mean sea level from three meteorological stations were also used. The variations of the observed daily mean sea level were studied at the six stations, giving low values in the winter season, and high ones in summer and spring seasons. The monthly mean sea level showed higher values during July and August and lower ones in the winter season. As the Arabian Gulf is generally considered a shallow sea, the meteorological conditions are the main cause of the sea level variation. This was shown by the variation of the daily mean sea level residual at the six stations. From the analyses of the coherence of several parameters, the pressure difference over the Gulf area did not give a noticeable effect with either the daily observed sea level or the daily sea level residual. Generally speaking, the important factor affecting the sea level variation in the Arabian Gulf is the pressure system covering the area either during the summer or the winter seasons

Analysis of thermomechanical fatigue of unidirectional titanium metal matrix composites

Thermomechanical fatigue (TMF) data was generated for a Ti-15V-3Cr-3Al-3Sn (Ti-15-3) material reinforced with SCS-6 silicon carbide fibers for both in-phase and out-of-phase thermomechanical cycling. Significant differences in failure mechanisms and fatigue life were noted for in-phase and out-of-phase testing. The purpose of the research is to apply a micromechanical model to the analysis of the data. The analysis predicts the stresses in the fiber and the matrix during the thermal and mechanical cycling by calculating both the thermal and mechanical stresses and their rate-dependent behavior. The rate-dependent behavior of the matrix was characterized and was used to calculate the constituent stresses in the composite. The predicted 0 degree fiber stress range was used to explain the composite failure. It was found that for a given condition, temperature, loading frequency, and time at temperature, the 0 degree fiber stress range may control the fatigue life of the unidirectional composite

Theory of gas bubble dynamics in oscillating pressure fields

The behavior of a permanent gas bubble in a liquid with an oscillating pressure field is analyzed with a linearized theory. If the assumption is made that conditions within the bubble are uniform, the thermodynamic relations found are as expected; i.e., at low frequencies the bubble behaves isothermally and at high frequencies the behavior becomes adiabatic. However, a more detailed analysis, which allows the bubble interior to vary not only in time but also in space, leads to an average isothermal behavior for the bubble even in the high-frequency limit

Theory of the acoustic absorption by a gas bubble in a liquid

A complete analysis of acoustic absorption by a spherical gas bubble is developed by the application of the classical Rayleigh method. The absorption considered is that due to the viscosity and heat conduction of the gas bubble. Specific results are presented for the S-wave scatter and absorption for the case of an air bubble in water, and the absorption effects of viscosity and heat conduction alone are calculated explicitly. The results found here are of similar magnitude to those found by Pfriem and Spitzer who used an approximate procedure