[en] Screw turns are known to be deformed as a result of the contact pliability of the nut and screw surfaces. The load distribution over the turns is investigated when fine thread is employed, when compression nuts are replaced by tension–compression and tension nuts, when the roughness of the working surfaces is increased, and when the load on the screw is increased.

[en] The Extreme Ultraviolet Lithography (EUVL) program currently is constructing an alpha-class exposure tool known as the Engineering Test Stand (ETS) that will employ 200mm wafer format masks. This report lists and explains the current specifications for the EUVL mask substrates suitable for use on the ETS. The shape and size of the mask are the same as those of a standard 200mm Si wafer. The flatness requirements are driven by the potential image placement distortion caused by the non-telecentric illumination of EUVL. The defect requirements are driven by the printable-defect size and desired yield for mask blank fabrication. Surface roughness can cause both a loss of light throughput and image speckle. The EUVL mask substrate must be made of low-thermal-expansion material because 40% of the light is absorbed by the multilayers and causes some uncorrectable thermal distortion during printing

[en] Full Text:Growth behavior of interfaces is usually described by a power-law of the growing interface width with time. This general scaling picture is an average behavior description, which may not be valid when only a finite number of interfaces is considered. In this work we study theoretically and experimentally the growth behavior of single interfaces and show that the particular growth function of the width always exhibits a non-monotonic, fluctuating behavior. This behavior results from competing mechanisms of normal growth and surface tension forces in the Quenched-noise Kardar-Parisi-Zhang (QKPZ) equation, and contains information on the growth process in this specific interface. We define a new measure of the interface width fluctuations in order to extract this information from experimental data. We analyze data of mercury droplets spreading on silver films, as well as data of water spreading on paper, in order to demonstrate the validity of our claim in a wide range of growing interfaces. The experimental results are compared to the numerical results of the QKPZ equation, for different cases of noise distributions

[en] The free layer switching properties of microstructured magnetic tunnel junctions have been investigated. The M-H loop of nonpatterned film shows ferromagnetic coupling with 10 Oe shifting associated with the interlayer roughness coupling. The MR curve of the patterned element shows stepped minor loop, less loop shifting, and larger coercive field due to shape anisotropy and stray field effects. MFM images of the element show nonuniform domain structures during reversal process

[en] The experimental investigation results on the vibration characteristics of the rods with artificial roughness in the axial flow are presented. It is shown that the roughness plays an important role in the mechanism of vibrations excitation. For the rods having artificial roughness with a relative size of 0.075+0.2 the phenomenon of dynamic instability has been revealed at the flowrates being by the order of magnitude smaller than those predicted by the Paidoussis theory. It is experimentally obtained that for the rods similar to those used as a nuclear reactor fuel element and heat exchanger tubes the critical velocities resulting in the vibration amplitude increase by the one or two order of magnitude are the values as much as 6-12 m/s. It is shown that the phenomenon revealed differs from a classic flutter by a number of attributes. (author)

[en] A global data set of land surface parameters is provided for the climate model ECHAM developed at the Max-Planck-Institut fuer Meteorologie in Hamburg. These parameters are: background (surface) albedo α, surface roughness length z_0y, leaf area index LAI, fractional vegetation cover or vegetation ratio c_y, and forest ratio c_F. The global set of surface parameters is constructed by allocating parameters to major exosystem complexes of Olson et al. (1983). The global distribution of ecosystem complexes is given at a resolution of 0.5⁰ x 0.5⁰. The latter data are compatible with the vegetation types used in the BIOME model of Prentice et al. (1992) which is a potential candidate of an interactive submodel within a comprehensive model of the climate system. (orig.)

[en] Dry frictional contact between two metallic surfaces, one cast iron and the other steel, is analyzed. The experiments were conducted using a pin-on-disk setup instrumented with force and acceleration transducers. The interactions between friction, wear, and vibrations and their dependence on normal load and system stiffness are investigated. The results indicate that stiffness has a significant effect on normal load at which transition takes place from mild to severe friction and wear. The variation of surface roughness with normal load for different stiffnesses is also examined. The different regimes of friction are observed, as the normal load is increased. They are characterized as steady state friction region, nonlinear friction region, region of transient friction with disturbances and region of self-excited vibrations. It is shown that the transition from the steady-state friction can be characterized by a sudden increase in the coefficient of friction and amplitude of slider oscillations

[en] It is suggested that whilst surface energy minimisation and the kinetic processes driving a system under sputter erosion towards such a state may exist, evidence is available which suggests that in many circumstances it is the kinetic process of erosion which dominates and dictates equilibrium or quasi-equilibrium crystal morphology. A much more extensive near-atomic scale study is required to determine the relative importance of both types of process under a variety of experimental conditions. (author)

[en] Decay type diffusion-limited reactions (DLR) over a rough surface generated by a random deposition model were performed. To study the effect of the decay profile on the reaction probability distribution (RPD), multifractal scaling analysis has been carried out. The dynamics of these autopoisoning reactions are controlled by the two parameters in the decay function, namely, the initial sticking probability (P_ini) of every site and the decay rate (m). The smaller the decay rate, the narrower is the range of α values in the α-f(α) multifractal spectrum. The results are compared with the earlier work of DLR over a surface of diffusion-limited aggregation (DLA). We also considered here the autopoisoning reactions over a smooth surface for comparing our results, which show clearly how the roughness affects the chemical reactions. The q-τ(q) multifractal curves for the smooth surface are linear whereas those for the rough surface are nonlinear. The range of α values in the case of a rough surface is wider than that of the smooth surface

[en] Published in summary form only