The article presents results of tests performed at the AGH-University of Science and Technology in Cracow on strength of single-coil inductors used as tools in electrodynamic machining of pipes. The character of volumetric Lorentz forces acting on coils of compressing and expanding inductors was discussed, and numerically determined distributions of stresses and displacements created in coils under the impact of these forces were presented. The problems presented are relevant when designing durable inductors intended for industrial applications.
The subject of investigations was the fragment of low peatland complex located close to Miękinia,
about 30 km from Wrocław. Within the range of the examined area of peat bog complex there can be distinguished three parts differing in their utilization and composition of species, namely: 1/ the area degraded by the
attempt to afforest it with alder trees Alnus glutinosa (L.) Gaertner, 2/ occasionally used bog hay meadow and
3/ typical peat forming phytocenosis. Total number of determined species, belonging to 11 phytosociological
classes, ranged 77, out of which more than a half constitute representatives of Molinio-Arrhenatheretea class.
As far as a non-afforested area was concerned, there were determined 5 phytocenosis, including 4 classified as
peat forming ones and one typical for post-bog meadows (Alopecuretum pratensis). The afforested area featured
herbaceous plant composition which indicated that the area with Alopecuretum pratensis phytocenosis had been
degraded. Analysis of environmental requirements, done with the use of ecological numbers, proved that prevailing number of species characterize similar requirements. It was mainly afforested part to feature taxons of
broader ecological scale, e.g. Polygonum bistora L., Carex hirta L. and Plantago lanceolata L.
The afforested area was purchased by a private person, therefore it can be assumed that the reason for such
a way of peatlands utilization was obtaining EU subsidies at minimum work effort. A higher financial profit,
however, would have been made by the owner if he had maintained a bog area as an extensive meadow.
The subject of the work is the analysis of thermomechanical bending process of a thin-walled tube made of X5CrNi18-10 stainless steel. The deformation is produced at elevated temperature generated with a laser beam in a specially designed experimental setup. The tube bending process consists of local heating of the tube by a moving laser beam and simultaneous kinematic enforcement of deformation with an actuator and a rotating bending arm. During experimental investigations, the resultant force of the actuator and temperature at the laser spot are recorded. In addition to experimental tests, the bending process of the tube was modelled using the finite element method in the ABAQUS program. For this purpose, the tube deformation process was divided into two sequentially coupled numerical simulations. The first one was the heat transfer analysis for a laser beam moving longitudinally over the tube surface. The second simulation described the process of mechanical bending with the time-varying temperature field obtained in the first simulation. The force and temperature recorded during experiments were used to verify the proposed numerical model. The final stress state and the deformation of the tube after the bending process were analyzed using the numerical solution. The results indicate that the proposed bending method can be successfully used in forming of the thin-walled profiles, in particular, when large bending angles and a small spring-back effect are of interest.
The paper covers the research on the process of solutionizing of 7075 aluminum alloy in cold tools during the stamping of a high-strength structural element (B-pillar’s base). For technological reasons, in order to obtain high strength parameters of the 7075 alloy, it is necessary to carry out a solutionization process, which allows to obtain dispersion strengthening during ageing process. Properly performed heat treatment of the alloy increases the strength of the material to approx. 600 MPa. The combination of the process of solutionization with simultaneous shaping is aimed at improving and simplifying technological operations of aluminum alloy stamping, shortening the duration of the manufacturing process and reducing production costs. The manufactured lower part of the B-pillar will be used for the verification of the validity of the developed method. During the experiment, a series of stamping tests were carried out, in which the lubricants, pressure and position of the upper and lower blankholders were the variables. The obtained results allow to estimate the influence of the cooling conditions on the strength of the drawpieces obtained after the process of artificial ageing. In order to verify and analyse the results more quickly, a numerical simulation was carried out.
In the paper the results of experimental research of the process of flow forming of cylindrical drawpieces were presented. The drawpieces were made of the 3.1 mm thick AMS 5596 sheet by drawing process. Tests were performed on two-roller metal spinning machine of a vertical axis Leifeld SFC 800 V500.
The main purpose of this research was to determine the relationship between relative thickness reduction and the mechanical properties of tested material. Knowledge of these dependencies is especially useful in designing machines’ components manufactured by flow forming, in the selection of parameters of realization of this technological process as well. Mechanical properties were determined on the basis of uniaxial tensile of the micro samples obtained from the drawpieces: (I) after cold flow forming, (II) after cold flow forming and in-process heat treatment. Obtained results were shown graphically in the diagrams and their analysis was carried out. In addition, the microstructure of the sheet material tested after drawing and flow forming is presented.
The study proposed the model of “guide mark” defects formation on the internal surface of pipes, produced on PRM mills of PRP – 140. The research of pipe forming at plug rolling mill with stub mandrel has been carried out; regularities of the dimensionless parameters characterizing the deformation of the gap release, depending on the reduction ratio, were determined. The model of “guide mark” defect formation on the internal surface of the pipe has been proposed. This allows for lesser wall thickness variation of rough tubes. It has been shown that, when using dioctahedral pass designs in comparison with hexagonal pass designs the proportion of displaced volume along the pipe axis is greater but the value is lower; thereby, the risk of “guide mark” defect forming is reduced.
This study presents a description of the mechanics of forming dough pieces into cylindrical (cylinder-like) shapes. Based on the configuration of forming, the movement of the formed piece and its surface deformations were described. Kinematic relationships concerning the dough piece material as a rheological fluid were formulated. Next, the relationships coupling the kinematic quantities present with both descriptions were determined. The components of the deformation rate tensor, presented in the assumed forming configuration (cylindrical coordinate system), describe the velocity distribution on the surface of dough piece being formed and deformed. The determined kinematic quantities and their interrelations may be used to describe the process of forming dough pieces into cylindrical shapes.
In this paper, the author derives theoretical formulae for calculating of squeezing forces. This report is the first one concerning the method of forming stepped shafts by longitudinal cold rolling. The formulae of the radial squeezing forces for the final passage of longitudinal rolling were calculated under the Huber hypothesis of plastic deformation and maximum shear stress.
The urban form creates the city structure, whose spatial values not only shape the functionality of the city, but also its identity, whose the most important determinant is the urban tissue. The subject of the study is the analysis of selected historical areas of Cracow in the scope of composition and readability of their urban structure. The analysis focuses on the identification of the most important aspects of spatial renewal processes of these spaces. These processes aimed at strengthening their potential as local centres, that can become a factor stimulating the development of the individual urban units. The increase in the attractiveness and quality of public spaces will positively affect the degree of their perception by the inhabitants and the social relations taking place in them. This in turn, influences the degree of the social involvement in development processes and the creation of more or less spontaneous, bottom-up activities.
When and where did life first appear on Earth? Humankind has been pondering this question for centuries. The discovery of ancient microalgae is providing a partial answer.
Public spaces designed in a reasonable way make up an element that heals the city. They are both areas dedicated to collective recreation and a catalyst for social activities. Regarding a rational space exploitation, a reuse of grounds that are being liberated as a result of cities reorganization and revitalization of postindustrial areas should be a clue. The latter represent a unique esthetic virtues due to specificity of their original function. Comparison of the selected designs and scientific approaches had been made in order to take the floor in a debate about devastated areas revitalisation and city – and center-making capability of cultural investments. The importance of psychological links between human and his environment is set down by the presence of features defining the open form in a mentioned projects.
The article is an introduction to the monographic content of a volume containing articles dedicated to contemporary models of building residential districts in Europe, where the issue of an attractive, beautiful architectural form must integrate the dimension of energy efficiency. Individualism must be subject to flexible regulations so that the current understanding of the concept of spatial order brings with it commonly desirable qualities as an effective strategy against the processes of the city›s sprawl. Attached is the output of the HOPU-S URBACT II project (2007-2013), which became an inspiration for the topic.
This article is devoted to the official forms in the inflection of chosen toponyms in Poland and the variety of dialectal singular and plural place names. The variety of place names often diverges from the rules of language use, and causes language users problems. The toponyms have peculiar, locally used inflected forms; the outside-linguistic (non-linguistic) factors that are social and local factors, play an important role in the inflection of place names. The local population often uses other forms than those recommended by official sources. I focus my attention on the genitive forms of toponyms because it is mainly here that one can see clear variations in the official and local inflection of place names. The material shows that the singular masculine toponyms have genitive endings: -a (in the official variety), -u (in the local variety), for example Biłgoraj, gen. Biłgoraja, but in the local dialect: biłgoraju. The singular feminine place names have genitive endings: -ej (in the official variety), -y||-i (in the local variety): Brzezowa, gen. Brzezowej, but Brzezowy in the local dialect. The plural toponyms have genitive endings: -ø, -ów, -i (-y), but in the local circulation the ending -ów is dominant and demonstrates a wider expansion in use. For example Brzózki, gen. Brzózek, in the local variety Brzuskuf; Budy, official gen. Bud, but Buduf; Burnie, gen. Burni, in the local dialect: Burniuf. The gathered material reflects a hesitation in the inflection of toponyms, as the linguistic customs and presented dialectal records of forms of genit ives of place names show a significantly diverse approach towards the Polish language.
The author tries to explain what consequences for social morality ensue from the assumption that moral attitudes are expressed not only in words but also in reactive attitudes. P.F. Strawson assumes that acts of resentment can alter attitudes of those who have triggered them by their behavior. On the other hand, we are ready to control our outbursts of short temper and anger to a certain degree if we take into account agents’ motives and their limited ability to exercise self-control. Moreover, it seems that reactive attitudes – though less precise than verbal rebuke – are more frank and straightforward. Nevertheless, why must I, when I hear a mediocre academic researcher brag over and over again about his apparently essential contribution to philosophy, curb my moral assessment of his self-importance to the level of my irritation? Why should I feel constrained to keep my moral disgust in tune with my impatience mixed with amusement? Why shouldn’t I continue to believe that I can be an amiable character and a rigorous moral person at the same time?