Privatization of urban services focuses often on the involvement of foreign enterprises. This contribution deals with micro-privatization, the partial transfer of government responsibility for solid waste collection to micro-enterprises. It tries to shed light on whether the current private sector participation (PSP) of micro-enterprises in solid waste collection service is the best way to capt...

A polar and neutral polymethacrylate-based monolithic column was evaluated as a hydrophilic interaction capillary electrochromatography (HI-CEC) stationary phase with small polar-neutral or charged solutes. The polar sites on the surface of the monolithic solid phase responsible for hydrophilic interactions were provided from the hydroxy and ester groups on the surface of the monolithic station...

The new lamellar phases [Zn(2,2'-bpy)(2)(H(2)O)(2)](ZrF(6))·3H(2)O (I) and [Ni(2,2'-bpy)(3)](MoO(2)F(4))·5H(2)O (II) (bpy = bipyridine), which are built from a chiral cation and respectively an inherently nonpolar and a polar anion, provide two contrasting structures with respect to chirality and polarity in the solid state. Each nonpolar layer of I contains enantiomers of both handednesses; co...

In this paper, we focus on the first stage of transition to Rayleigh–Bénard convection in soft-jammed systems (yield stress fluids) confined a parallelepiped box heated from bottom. Up yielding, material is solid-state with constant elastic modulus. By means linear thermoelastic model, an analytical solution for stresses and strains induced by gravity temperature gradient derived. The allows us...

A new planar structure of solid propellant micro -rocket for micro-spacecraft and Micro-Air-Vehicle applications is reported in this paper. We have successfully fabricated an array of micro-rockets using MEMS technology. For a lowpower consumption, the micro-igniter used here is a resistor deposited on a low tensile stress thin membrane to ensure a good heat transfer to the propellant. Experime...

This paper concentrates on the reflection of plane waves in the mixture of generalized thermo elastic solid half-space. There exists quasi dilatational waves i.e. qP1, qP2, qT and two rotational waves S1, S2 in a two dimensional model of the solid. The boundary conditions are solved to obtain a system of five non-homogeneous equations for amplitude ratios. These amplitude ratios are found to de...

Elastic fibers are composed of peripheral microfibrils and a core of elastin. Whether elastic-fiber microfibrils are specialized and whether their structure differs from that in non-elastic tissues remain to be determined, however. In this study, the ultrastructure of elastic-fiber microfibrils was examined in monkey (Macaca mulatta and Macaca fuscata) gingiva. In contrast to the straight micro...

We investigate the weakening of elastic materials through randomly distributed circles and cracks numerically and compare the results to predictions from homogenization theories. We find a good agreement for the case of randomly oriented cracks of equal length in an isotropic plane-strain medium for lower crack densities; for higher densities the material is weaker than predicted due to precurs...