Neighbouring as a type of social interchange and multi-dimensional social phenomenon is of funda-mental importance in the social sciences and problems associated with intercultural and interethnic neighbouring are currently on the increase. Contemporary migration processes and ethnic diversity in Poland are relatively new issues that are reflected in the experiences of both migrants and representa-tives of the host society. The aim of this article is to analyse intercultural neighbourly contacts be-tween Poles and migrants in Warsaw in the context of Erving Goffman’s sociology of interaction. These contacts and the social processes they involve are of great importance when it comes to mi-grants’ integration in their new place of residence. The article considers how glances, gestures and behaviours are interpreted, leading to the formation of specific opinions and attitudes between mi-grants and Poles. Both ‘unfocused’ and ‘focused’ interactions are analysed, with an emphasis on ex-pectations and definitions of tactful behaviour in intercultural neighbourly encounters and the concept of ‘polite indifference.’ Conclusions are based on semi-structured interviews conducted with Poles and migrants from Vietnam, Turkey and African countries living in Warsaw, Poland.

The paper presents descriptions of bridge disintegration types and contact mass loss in the bridge stage. There is presented Matlab solvers to solve equation describing dynamic changes of temperature in the bridge region. The final result of program calculations is the mass loss and the volume of the metal of contacts which was lost during the bridge stage.

A revision of the standard approach to characterization of thin-semiconductor-layer Hall samples has been proposed. Our results show that simple checking of I(V) curve linearity at room temperature might be insufficient for correct determination of bias conditions of a sample before measurements of Hall effect. It is caused by the nonlinear behaviour of electrical contact layers, which should be treated together with the tested layer a priori as a metal-semiconductor-metal (MSM) structure. Our approach was examined with a Be-doped p-type InAs epitaxial layer, with four gold contacts. Despite using full high-quality photolithography a significant asymmetry in maximum differential resistance (Rd) values and positions relative to zero voltage (or current) value was observed for different contacts. This suggests that such characterization should be performed before each high-precision magneto-transport measurement in order to optimize the bias conditions.

The paper presents the results of numerical simulation of processes aimed at production of nanostructures with the use of oil emulsions in water. The appropriate molecular models of water and oil, as well as the model of the substance which would sediment at the water – oil interface, are looked for. Such substance, after suitable solidification, would become the main component of the produced material. For the described simulations, the Molecular Dynamics method has been used throughout this paper.

Thrust bearing model is developed for fluid flow calculation and for determination of bearing integral characteristics in the presence of sliding surfaces closure and shaft angular displacements. The model is based on the coupled solution of the problem of incompressible fluid flow between the sliding surfaces and the problem of bearing and shaft elements deformation under the action of the fluid film pressure. Verification of the bearing model results is carried out by the comparison versus the fluid flow calculation results obtained by STAR-CD software and the experimental and theoretical results represented in the certain literature. Thrust bearing characteristics are determined versus sliding surfaces closure and rotating disk (runner) angular displacements. The contribution of the sliding surfaces deformations into bearing integral characteristics is estimated.

This paper presents a methodology for contact detection between convex quadric surfaces using its implicit equations. With some small modifications in the equations, one can model superellipsoids, superhyperboloids of one or two sheets and supertoroids. This methodology is to be implemented on a multibody dynamics code, in order to simulate the interpenetration between mechanical systems, particularly, the simulation of collisions with motor vehicles and other road users, such as cars, motorcycles and pedestrians.

The contact detection of two bodies is formulated as a convex nonlinear constrained optimization problem that is solved using two methods, an Interior Point method (IP) and a Sequential Quadratic Programming method (SQP), coded in MATLAB and FORTRAN environment, respectively. The objective function to be minimized is the distance between both surfaces. The design constraints are the implicit superquadrics surfaces equations and operations between its normal vectors and the distance itself. The contact points or the points that minimize the distance between the surfaces are the design variables. Computational efficiency can be improved by using Bounding Volumes in contact detection pre-steps. First one approximate the geometry using spheres, and then Oriented Bounding Boxes (OBB).

Results show that the optimization technique suits for the accurate contact detection between objects modelled by implicit superquadric equations.

This article proposes that the ’imāla phenomenon was an innovation in the Najd region. The non-’imāla form was the traditional form because it is the vowel production in the available Ancient North Arabian data. The article will separate the use of ’imāla as an assimilatory vowel from the Najdi non-assimilatory production by analyzing the testimonial data in the traditional books of grammar. Finally, the article will use the available genealogical literature to establish an approximate chronology for the innovation and to justify the spread of the innovation among the pre-Islamic tribes.

The purpose of the paper is the attempt to point one of the most important aspects of the cultural contact of the Poland and Arabic countries with the consideration of the historical perspective. The author assumes that the language is the basic carrier of such contacts and also the main area of the mutual influences. Therefore, she discusses the Arabic and Polish relations mostly on the level of the translation of the literary and scientific output of both sides, as well as the linguistic interference mainly in the aspect of the lexical borrowings. The author quotes many examples of such linguistic contacts and underlines their great meaning in the existence and development of other types of relations: political, commercial, and cultural.

Energy efficiency improvement and ecological safety of heat power plants are urgent problems, which require scientifically grounded approaches and solutions. These problems can be solved partly within the presented heat-and-power cycles by including contact energy exchange equipment in the circuits of existing installations. A significant positive effectis obtained in the contact energy exchange installations, such as gas-steam installation ‘Aquarius’ and the contact hydrogen heat generator that also can use hydrogen as a fuel. In these plants, the efficiency increases approximately by 10–12% in comparison with traditional installations, and the concentration of toxic substances, such as nitrogen oxides and carbon monoxide in flue gas can be reduced to 30 mg/m3and to 5 mg/m3, respectively. Moreover, the plants additionally ‘generate’ the clean water, which can be used for technical purposes.

The human environment consists of a large variety of mechanical and biomechanical systems in which different types of contact can occur. In this work, we consider a monopedal jumper modelled as a three-dimensional rigid multibody system with contact and simulate its dynamics using a structure preserving method. The applied mechanical integrator is based on a constrained version of the Lagrange-d’Alembert principle. The resulting variational integrator preserves the symplecticity and momentum maps of the multibody dynamics. To ensure the structure preservation and the geometric correctness, we solve the non-smooth problem including the computation of the contact configuration, time and force instead of relying on a smooth approximation of the contact problem via a penalty potential. In addition to the formulation of non-smooth problems in forward dynamic simulations, we are interested in the optimal control of the monopedal high jump. The optimal control problem is solved using a direct transcription method transforming it into a constrained optimisation problem, see [14].

The text discusses words occurring in the Polish-East Slavic borderlands and prevalent in eastern Polish dialects. Differntiation between old references and loans in this area is not always easy. The material presented here is very diverse. In the case of certain words, identifying them as East Slavic loans with an indisputable source is possible, while in the case of others it is difficult to identify the direct source of the loan. Among the words recorded in the East Slavic borderlands we can find those whose range in Polish dialects seems to indicate the possibility of Ruthenian influence; however, their Polish phonetic form implies their native origin and one should speak about an old reference in this respect. We also encounter Pan-Slavic words, where a doubt arises as to whether they are loans or old references in Polish in the East Slavic area and Eastern Poland.

Significant differences in the physical and mechanical properties exist between the rock masses on two sides of an ore-rock contact zone, which the production tunnels of an underground mine must pass through. Compared with a single rock mass, the mechanical behavior of the contact zone composite rock comprising two types of rock is more complex. In order to predict the overall strength of the composite rock with different contact angles, iron ore-marble composite rock sample uniaxial compression tests were conducted. The results showed that composite rock samples with different contact angles failed in two different modes under compression. The strengths of the composite rock samples were lower than those of both the pure iron ore samples and pure marble samples, and were also related to the contact angle. According to the stress-strain relationship of the contact surface in the composite rock sample, there were constraint stresses on the contact surface between the two types of rock medium in the composite rock samples. This stress state could reveal the effect of the constraint stress in the composite rock samples with different contact angles on their strengths. Based on the Mohr-Coulomb criterion, a strength model of the composite rock considering the constraint stress on the contact surface was constructed, which could provide a theoretical basis for stability researches and designs of contact zone tunnels.

The paper presents the results of studies on quartzite milling in a ball mill. The milling was conducted in a batch system, for diversified compositions of balls. The milling product was subjected to granulometrical, morphological and strength analyses. On the basis of the developed Reid's theory and using the Austin-Gardner equation, a form of the function circumscribing the specific rate of comminution of selected size fractions was determined. The values of the breakage rate function bi, j for the mill's apparatus conditions were determined. The impact was investigated for a variable number of grinding media contact points on the values of specific rate S and the values of the breakage rate function bi, j. Furthermore, the values of coefficients occurring in the equations circumscribing the specific rate of milling S and breakage parameter bi, j were determined.