This investigation is carried out to evaluate the repair and strengthening the techniques of elliptical paraboloid reinforced concrete shells with openings. An experimental program of several different techniques in repair and strengthening is executed. The materials, which are considered for strengthening, are; Glass fiber reinforced polymers GFRP at different position of the shell bottom surface, steel strip and external tie. They loaded by four concentrated loads affected on the corners of the opening. The initial and failure loads as well as the crack propagation for the tested shells at different loading stages, defl ections and failure load for repaired and shells are recorded. A non-linear computer program based on finite element techniques is used to study the behavior of these types of shells. Geometric and materials nonlinearities are considered in the analysis. The efficiency and accuracy of computer program are verified by comparing the program results with those obtained experimentally for the control shell with opening and strengthened shells.
U-turn lanes eliminate left turns at intersections and allow the manoeuvre to be made via median crossovers beyond the intersection. However, there are many situations where road infrastructures are characterized by the reduced width of the median. It is clear that, in such situations, we must adopt design criteria that take into account limitations imposed by the width of the cross-section of the road. This is the reason why it is necessary to adopt design solutions which expect a complete reorganization of the road section affected by the insertion of U-turns. In this paper, we intend to propose original guidelines for U-turn lane design, suitable to guarantee both the necessity to offer a high level of functionality of the road sections to be implemented by U-turns, and the principles of safety in order to reduce unsafe conditions during inversion manoeuvres as much as possible.
The main bulk density representation in the molding material is opening material, refractory granular material with a particle size of 0.02
mm. It forms a shell molds and cores, and therefore in addition to activating the surface of the grain is one of the most important features
angularity and particle size of grains. These last two features specify the porosity and therefore the permeability of the mixture, and
thermal dilatation of tension from braking dilation, the thermal conductivity of the mixture and even largely affect the strength of molds
and cores, and thus the surface quality of castings. [1]
Today foundries, which use the cast iron for produce of casts, are struggling with surface defects on the casts. One of these defects are
veining. They can be eliminated in several ways. Veining are foundry defects, which arise as a result of tensions generated at the interface
of the mold and metal. This tension also arises due to abrupt thermal expansion of silica sand and is therefore in the development of
veining on the surface of casts deal primarily influences and characteristics of the filler material – opening material in the production of
iron castings.
This article examines the process of opening datasets accumulated by public institutions, and its impact on the rise of new types of journalism, in particular data journalism.
Nominal strength reduction in cross ply laminates of [0/90]2s is observed in tensile tests of glass fiber composite laminates having central open hole of diameters varying from 2 to 10 mm. This is well known as the size effect. The extended finite element method (XFEM) is implemented to simulate the fracture process and size effect (scale effect) in the glass fiber reinforced polymer laminates weakened by holes or notches. The analysis shows that XFEM results are in good agreement with the experimental results specifying nominal strength and in good agreement with the analytical results based on the cohesive zone model specifying crack opening displacement and the fracture process zone length.
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.
A total of 704 fishes representing 39 species were examined. Twenty five digenean species were recognized. Only one species previously found by the present author in a fiord of this area was absent in the material. Pelagic species were usually not parasitized by digeneans, while demersal fishes were normally found to be infected. Results of the present study are compared to those from fiords. Seven species were found to be widely distributed. Two of them, Macvicaria pennelli and Genolinea bowersi, were associated with an inshore fiord environment and could be used as biological tags indicating the association of hosts with this kind of environment. Three of widely distributed species, Lepidapedon garrardi, Elytrophalloides oatesi and Lecilhaster macrocotyle, were not clearly associated with any environment.
Gonocerca phycidis, Neolebouria antarctica and other less widely distributed species, with the exception of Postmonorchis variabilis, were associated with deep part of fiords and/or open sea shelf environment. The level of infection of open sea fish at the South Shetlands was low. Many fish species living at South Georgia were massively infected; the dominant species in this area is E. oatesi, which was rare off the South Shetland Islands. A total of 45 digenean species occurring in the Antarctic fish were listed. Eleven of them were not endemic.
This work aims to comprehensively describe the current state of the concept of green infrastructure. It is thus meant to fill in a gap in Polish literature as no comprehensive works concerning green infrastructure have been published in our country even though we have witnessed several such works in other places in the world. The book is mostly addressed to urban planners, spatial planners and landscape architects and it focuses on issues related to developing strategies or green nalyzingture network designs. It is difficult to establish when (and by whom) the term “green infrastructure” was actually coined. The performed literature search indicates that various authors attribute its beginnings to different publications. There is, however, much more consensus regarding the origins of the idea of green infrastructure. Among the concepts regarded as the bases for the notion of green infrastructure we can discern two principal ones: the concept of ecological networks and the concept of greenways (in the US). In Poland, such concepts included the Ecological System of Protected Areas (in Polish: Ekologiczny System Obszarów Chronionych) and System of Open Spaces (in Polish: System terenów otwartych). There is some disagreement regarding the origins of green infrastructure in cities. Analysis of defi nitions of green infrastructure seen in both scientific publications as well as guides and formal documents leads to a single conclusion – we should accept the diversity of interpretations and approaches. A similar diversity in approaches can also be found when looking at the presented typologies. By analyzing the rationale behind the typologies, we can discern three major criteria used by the authors: land cover, land use and ecological value, which is usually associated with formal protection of specifi c areas. The principles of green infrastructure development can be divided into planning-related (multi-functionality, connectivity, multi-scale approach, multi-object approach, cost-effective approach) and governance-related (strategic approach, integration, social inclusion, transdisciplinarity, stakeholder inclusion).
Green infrastructure provides people with a multitude of more or less measurable benefits. For the last several years they have been identified and quantified using a concept of ecosystem services. These services are always provided in certain confi gurations, which means that it is only possible to obtain the benefits if the services generating those benefi ts are not contradictory to each other. For several years now, the European Commission has been conducting research on the scope, possibilities and methods of implementing the concept of green infrastructure in the member states. However, the EU’s offi cial position on this subject was declared only in 2013 via Communication from the Commission to the European Parliament, the Council, the European Economic and Social Committee and the Committee of the Regions – Green Infrastructure (GI) — Enhancing Europe’s Natural Capital.
In both EU member states and the United States, non-governmental organizations are the main advocates of the concept of green infrastructure. They have been recently joined by governmental and self-government agencies. The case studies of already developed strategies and designs of the concept of green infrastructure presented in this book illustrate a great diversity of approaches. It is particularly noticeable in the way of identifying specific components and principles of planning and implementation of green infrastructure networks. These differences come mainly from the varying scale of development, adopted interpretations of the notion of green infrastructure as well as specifi c natural, social and sometimes economic conditions in particular areas. Based on the knowledge and experience gathered from the analysis of those cases, we can point out the following problems that Polish planners need to face in order to develop and implement green infrastructure for Polish rural communes, cities and regions:
• good selection of the formula and defi nition of green infrastructure that is appropriate for the scale, specifi c conditions of the area, needs of the inhabitants and ambitions of the authorities;
• good identification of areas with potential for green infrastructure development that is appropriate for the scale and problems of a specific area (city, village, region)
• identification of the scope and degree of confl ict between ecosystem services provided by individual components of green infrastructure;
• development of a spatial concept that includes the problem of the inherent conflict between the expected benefits (especially regulation and maintenance versus cultural) coming from individual components of green infrastructure;
• proposal of appropriate instruments for implementing the concept and resolving the problem of its coexistence with other concepts of shaping the ecological structure of cities, rural communes and regions in Poland.
Summing up, the concept of green infrastructure can be viewed as the ultimate synthesis of all former ideas dealing with the development of ecological structure of cities, open landscapes and regions. In most European countries, apart from Great Britain, the concept of green infrastructure is currently in its implementation phase. Therefore, its true – not paper – history is about to begin and it will probably look diff erent in every country. It will be aff ected by various traditions of development planning, the already developed concepts, degree of involvement of the authorities and – probably above all – the will of those that expect quantifiable benefits from green infrastructure.
Scientists around the world agree that nowadays, science is facing severe challenges like poor peer-review system, replicability crisis, or locked science behind paywalls. The National Science Center addresses at least some of them by introducing procedures that promote integrity, ethics, social responsibility, transparency, and openness in science.
A ccording to the Polish Geological and Mining Law the granting of a concession for the exploration of a hydrocarbon deposit and the production of hydrocarbons from a deposit, or a concession for the production of hydrocarbons from a deposit in Poland is proceeded according to a tender procedure or open door procedure (upon a request of an entity). O n June 28, 2018 the Polish Minister of the Environment announced 5 tender areas. These areas (promising for discoveries of conventional and unconventional oil and gas deposits) were selected by the geologists of the Polish Geological Institute-NRI and Department of Geology and Geological Concessions of the Ministry of the Environment based on the geological data resources stored in the National Geological Archive. These are: Bestwina-Czechowice, Królówka, Pyrzyce, Złoczew i Żabowo. The main exploration target on the areas located in central and north-western Poland (Pyrzyce, Żabowo and Złoczew) is related to Permian Rotliegend sandstones and carbonates of the Zechstein/Main Dolomite. The Bestwina-Czechowice and Królówka areas (southern Poland) are prospective for conventional and hybrid-type accumulations of gas in the Miocene of the Carpathian Foredeep below the Carpathian Overthrust and in the Paleozoic-Mesozoic basement. The beginning of the 4th bidding round for hydrocarbon concessions is planned in Q4 2019. The entity can also choose the area and apply for a license submitting an application to the Ministry of the Environment. The area indicated by the entity cannot be the subject of a tender or any other concession, and the maximum acreage is 1,200 km2.
The article discusses the problem of the supply of a by-product, which is synthetic gypsum produced as a result of flue gas desulphurization in conventional power plants. The state of production and forecast for the future are presented. Currently, synthetic gypsum is almost entirely used as a raw material in the gypsum products plant located in the immediate vicinity of the power plant. Since the mid-1990s, in Poland, an increase in the production of synthetic gypsum associated with the construction of a flue gas desulphurization installation in Polish conventional power plants has been observed. In the near future, the upward trend will continue in connection with the construction of new coal units in power plants. Significant surpluses of this raw material will appear on the market, which will not be used on an ongoing basis in the production of gypsum components. However, due to the EU’s restrictive policy towards energy based on coal and lignite, within the next few decades, the share of conventional power plants in energy production will be gradually reduced. As a consequence, the supply of synthetic gypsum will also gradually decrease. Therefore, it is advisable to properly store the surplus of this raw material so that it can be used in the future. Taking this into account, it is already necessary to prepare methods for storing the expected surpluses of synthetic gypsum. For this purpose, post-mining open pits are particularly suitable, especially in mines of rock raw materials. The article proposes a legal path enabling the post-mining open pits to be transformed into a anthropogenic gypsum deposit.
The economic envelopes obtained by optimization techniques in open pit mining are transformed into operational phases that are suitable for extraction through ramp designs. This process is performed with the aid of specialized design software, which is still very manual, time consuming and highly dependent on the expertise of the planner. In this paper, we introduce a new methodology based on a mathematical model to automatically propose the design of ramps from the economic envelope of a pushback, with the resulting envelope having the maximum value. The developed model was tested against a real case scenario showing reasonable and useable solutions for the planner. Using this approach, a planner can evaluate several alternatives in a reasonable time before selecting the final design.
Open pit mining has severe environmental impacts on the environment of mining region. Mined land reclamation procedure in open pit mining contains numerous activities in order to prevent, monitor, control reduce environmental impacts of a project from exploration stage to exploitation, to mine closure and beyond. After mine closure, a permanent Post Mining Land Use (PMLU) should be implemented as an appropriate choice for use of different sections of mined land in an open pit mine. Mined land in open pit mining comprise different sections as pit(s), waste dump(s), tailing pond(s), roads, areas for on site facilities and free land zones which are not mined. The selected PMLU for each section of mined land as the most appropriate alternative based on the different points of view is presented as Optimum Post Mining Land Use (OPMLU). OPMLU for each section of mined land and the specifications of mine site are the most decisive parameters which affect the quality and volume of mine closure procedure, reclamation process and their costs. Furthermore, to define Ultimate Pit Limit (UPL) in open pit mining, consideration of mine closure and reclamation costs is essential as other costs of a mining project. Therefore, defining OPMLU for each section of mined land is essential within planning phase of an open pit mining project. In this paper the applicable alternatives of PMLU, the effective criteria, attributes and sub-attributes for defining OPMLU are presented for pit area amongst different sections of mined land. Pit area amongst different sections of mined land has more significant effects on the adjacent environment and also on defining OPMLU for the other sections of mined land. As there are several alternatives of PMLU, several criteria, attributes and sub-attributes for defining OPMLU, Multi Attribute Decision Making (MADM) methods are efficient techniques to define OPMLU for pit area. Fuzzy sets use a spectrum of numbers instead of using absolute numbers. As well, the nature of the effective parameters for defining OPMLU is same as Fuzzy numbers including incremental changes without definite limits thus the use of Fuzzy MADM modeling can produce more reliable results than the other techniques. As pair-wise comparisons and judgments through Fuzzy numbers have proper consistency with the nature of the effective parameters for defining OPMLU accordingly, a model is developed to attain OPMLU for pit area through Fuzzy Analytical Hierarchy Processing (FAHP). As a case study the model was implemented in Sungun copper mine in Northwest of Iran. Lumber production was defined as OPMLU for the pit area in this mine. It is finally concluded that using the developed model, OPMLU is defined for pit area as a key parameter to estimate reclamation costs in planning phase of an open pit mining project.
Geometry of plate heat exchangers (PHE) is characterized by a complex net of narrow channels. It enhances turbulence and results in better heat transfer performance. Theoretically, larger number of channels (plates) should proportionally increase the PHE heat power capacity. In practice a nonuniform massflow distribution in consecutive flow channels can significantly deteriorate the overall heat exchange performance. The flow maldistribution is one of the most commonly reported exploitation problems and is present in PHE with and without phase-change flows. The presented paper investigates numerically a flow pattern in PHE with evaporation of R410A refrigerant. Various sizes of PHE are considered. The paper introduces a robust methodology to transform the complicated geometry of a real 3D PHE to its 2D representation. It results in orders of magnitude faster calculations and allows for fast evaluation of different geometrical changes of PHE and their effect on flow maldistribution.
The pump performance and occurrence of cavitation directly depends on different operating conditions. To cover a wide range of operation conditions for detecting cavitation in this work, investigations on the effect of various suction valve openings on cavitation in the pump were carried out. In order to analyse various levels of cavitation in different operation conditions, the effect of the decrease in the inlet suction pressure of the centrifugal pump by controlling the inlet suction valve opening was investigated using this experimental setup. Hence, the acoustic and pressure signals under different inlet valve openings and different flow rates, namely, 103, 200, 302 l/min were collected for this purpose. A detailed analysis of the results obtained from the acoustic signal was carried out to predict cavitation in the pump under different operating conditions. Also, the acoustic signal was investigated in time domain through the use of the same statistical features. The FFT technique was used to analyse the acoustic signal in the frequency domain. In addition, in this work an attempt was made to find a relationship between the cavitation and noise characteristics using the acoustic technique for identifying cavitation within a pump.