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Search results for: COMMODITY EXCHANGES
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Two-phase thermosiphon heat exchanger for heat recovery
PublicationW pracy przedstawiono wyniki badań eksperymentalnych dotyczących wpływu geometrii pęku rur, rodzaju powierzni przejmowania ciepła parownika oraz płynu pośredniego na całkowitą wydajność dwufazowego termosyfonowego wymiennika ciepła (DTWC). Badaniu poddano sześć prototypowych DTWC z dwiema podziałkami rur w parowniku, dla trzech rodzajów powierzchni rur parownika oraz z zastosowaniem trzech rodzajów płynów pośrednich. Lepszą wydajność...
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The effect of heat exchanger geometry on adsorption chiller performance
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Flow maldistribution and its mitigation in mini heat exchangers
PublicationIn the present paper, a detailed numerical investigation has been carried out to analyze the flow maldistribution in 50 parallel 1 mm x 1 mm rectangular minichannels and 1 mm depth minigap section with rectangular, trapezoidal, triangular or concave mani-folds in Z-type flow configuration (16 different cases). The working medium was ethanol and the mass flow rate was 5×10-4 kg/s. Both sections was heated from the bottom side. Heat...
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Boiling heat transfer performance of the thermosiphon heat exchanger
PublicationPrzedstawiono wyniki badań eksperymentalnych prototypowego, termosyfonowgo wymiennika ciepła. W szczególności określono wpływ geometrii pęku rur, stanu powierzchni rurek oraz poziomu cieczy w parowniku na wydajność cieplną wymiennika.
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Bacterial community succession in an Arctic lake–stream system (Brattegg Valley, SW Spitsbergen)
PublicationThe factors affecting prokaryotic and virus structure dynamics and bacterial commu-nity composition (BCC) in aquatic habitats along a ca. 1500 m of the Brattegg Valley lake–stream system (SW Spitsbergen) composed of three postglacial lakes created by Brattegg Glacier meltwater were examined. A high number of small-volume prokaryotic cells were found in the recently-formed, deep, upper,...
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Molecular characteristics of community-associated methicillin-resistant Staphylococcus aureus strains for clinical medicine
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Community innovators: 'shock troops' of the new order or safety brake in the era of 'fast policy'?
PublicationArtykuł zawiera krytyczną analizę zinstytucjonalizowanej innowacji w zakresie polityki przestrzennej. Hasło kongresu ''szybkie planowanie'' jest interpretowane jako strategia modernizacyjna, mogąca w efekcie preferować ograniczoną liczbę prorynkowych modeli rozwoju i rolę głosu eksperckiego. Artykuł podsumowuje pierwsze doświadczenia związane ze społecznym oporem przeciwko takim formom kształtowania polityki rozwoju miast w Polsce.
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Modeling water exchange in the Oder River mouth area
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Heat and mass exchange in the process of condensation on critical droplets.
PublicationSformułowano model wzrostu kropli krytycznej podając równania zmiany masy i temperatury kropli. Pokazano formę zlinearyzowaną tych równań dobrze aproksymującą wzrost kropli w poblizu wymiaru krytycznego. Podano rozwiązanie układu zlinearyzowanego uzależniając zmianę temperatury od zmiany masy kropli i czasu charakterystycznego.
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ARIMA vs LSTM on NASDAQ stock exchange data
PublicationThis study compares the results of two completely different models: statistical one (ARIMA) and deep learning one (LSTM) based on a chosen set of NASDAQ data. Both models are used to predict daily or monthly average prices of chosen companies listed on the NASDAQ stock exchange. Research shows which model performs better in terms of the chosen input data, parameters and number of features. The chosen models were compared using...
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Free trade with the former COMECON Countries as Unequal Exchange
PublicationTwo authors of this chapter were born to the East of what was once The Iron Curtain and two to the West. From both angles, the two systems – capitalism and communism – seemed to be as contrary to each other as possible. Few people are aware that in terms of industrial and trade policy, both classical capitalism and communism had a common root in the theories of German economist Friedrich List (1789-1846) (List, 1841). In fact,...
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Culturable bacteria community development in postglacial soils of Ecology Glacier, King George Island, Antarctica
PublicationGlacier forelands are excellent sites in which to study microbial succession because conditions change rapidly in the emerging soil. Development of the bacterial community was studied along two transects on lateral moraines of Ecology Glacier, King George Island, by culture-dependent and culture-independent approaches (denaturating gradient gel electrophoresis). Environmental conditions such as cryoturbation and soil composition...
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Wystawa fotografii pt. Community Based Architectural Design in Practice/ Praktyka uspołecznionego projektowania architektonicznego
PublicationWystawa fotografii nt. praktyki w zakresie uspołecznienia procesu projektowania architektonicznego
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C2 NIWA Community-Segmentation Criteria and Building Brand Associations on the Example of a Selected Target Group
PublicationEvery organization which offers products or services wishes to communicate with their customers in the most effective way. This kind of communication is based on proper selection of target groups, which are extracted in the process of market segmentation. That is way it is very important to ask the question to whom the message is to be directed and what kind of message we want to give. This article describes the selection criteria...
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Long-term effect of ZnO and CuO nanoparticles on soil microbial community in different types of soil
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Segmentation of academic community for the purposes of mobility plan development – case study of Gdansk University of Technology
PublicationThe objective of the paper is to analyse the structure of academic community for its transport behaviour and attitudes using the example of the Gdansk University of Technology (the GUT) in Poland. Once understood, the group can be divided into homogenous sub-groups and studied for their potential and ways to influence their behaviour, attitudes and transport patterns. The results may be used to develop dedicated actions designed...
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Performance of a plate heat exchanger operated with water-Al2O3 nanofluid
PublicationThis study is focused on experimental investigation of a selected type of brazed plate heat exchanger (PHEx). The main aim of the paper was to experimentally check the ability of nanofluids to enhance the performance of PHEx. A typical water-Al2O3 nanofluid was tested and compared to that of the base fluid, i.e. water. Nanoparticles were tested at the concentration of 0.1% and 1% by weight. Impact of the 1 day and 3 days break...
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Heat transfer characteristics of a two-phase thermosyphon heat exchanger
PublicationPrzedstawiono wyniki badań wpływu geometrii parownika, rodzaju rur użytych do budowy parownika, rodzaju cieczy pośredniej oraz poziomu cieczy nad najwyższym rzędem rur na działanie dwufazowego, termosyfonowego wymiennika ciepła. Zaprezentowano algorytm obliczeń przedstawionego wymiennika.
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HEAT TRANSFER CHARACTERISTICS OF ENHANCED SHELL AND COIL HEAT EXCHANGER
PublicationIn the paper authors presented their own constructions of shell and tube heat exchangers with intensified heat transfer. The shell and coils heat exchangers are in common use in heat ventilations and air conditioning systems. Those types of recuperators are quite simple constructions, the low value of pressure drops and good conditions of heat transfer. The present study shows an experimental investigation of the heat transfer...
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Application of Ion Exchangers in Speciation and Fractionation of Elements in Food and Beverages
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Performance of a plate heat exchanger operated with water-Al2O3 nanofluid
PublicationThis study is focused on experimental investigation of a selected type of brazed plate heat exchanger (PHEx). The main aim of the paper was to experimentally check the ability of nanofluids to enhance the performance of PHEx. A typical water-Al2O3 nanofluid was tested and compared to that of the base fluid, i.e. water. Nanoparticles were tested at the concentration of 0.1% and 1% by weight. Impact of the 1 day and 3 days break...
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Performance of a plate heat exchanger operated with water-Al2O3 nanofluid
PublicationThis study is focused on experimental investigation of a selected type of brazed plate heat exchanger (PHEx). The main aim of the paper was to experimentally check the ability of nanofluids to enhance the performance of PHEx. A typical water-Al2O3 nanofluid was tested and compared to that of the base fluid, i.e. water. Nanoparticles were tested at the concentration of 0.1% and 1% by weight. Impact of the 1 day and 3 days break...
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Separation of effluents from regeneration of a cation exchanger by membrane distillation
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Numerical analysis of high temperature minichannels heat exchanger performance
PublicationNowadays, the most difficult technological challenge in energy sector is connected with the gas micro-CHP units, dedicated to the distributed power generation. They are expected to be of high efficiency and at the same time of compact in size. Regarding the first reason, significant increase in microturbine efficiency can only be achieved by increase in the engine operating temperature. Therefore, one of the critical elements in...
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Selected studies of flow maldistribution in a minichannel plate heat exchanger
PublicationAnalysis of the state of-the-art in research of minichannel heat exchangers, especially on the topic of flow maldistribution in multiple channels, has been accomplished. Studies on minichannel plate heat exchanger with 51 parallel minichannels with four hydraulic diameters, i.e., 461 μm, 574 μm, 667 μm, and 750 μm have been presented. Flow at the instance of filling the microchannel with water at low flow rates has been visualized. The...
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Thermal-Hydraulic Studies on the Shell-and-Tube Heat Exchanger with Minijets
PublicationIn this paper a patented design of a heat exchanger with minijets, with a cylindrical construction is presented. It is followed by the results of its systematic experimental investigations in the single-phase convection heat transfer mode. Based on these results, validation of selected correlations (coming from the literature) describing the Nusselt number was carried out. An assessment of the heat exchange intensification level...
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Zniszczenie korozyjne wymiennika ciepła = Corrosion failure of a heat exchanger
PublicationPłytowy wymiennik ciepła ze stali 316L uległ zniszczeniu po trzech latach eksploatacji, wskutek perforacji po czyszczeniu nieodpowiednim środkiem czyszczącym.
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Transfer of charging information between exchanges of different network operators in multi-provider environment.
PublicationW pracy przedstawiono różne konfiguracje systemów taryfikacji i zaliczania w środowisku zdemonopolizowanym. Przeanalizowano różne opcje przepływu danych w takim środowisku i omówiono rozszerzenie sygnalizacji SS7, która jest opracowana przez ETSI i wykorzystywana dla aplikacji zaliczania.
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Molecular identification and genotyping of Staphylococci: genus, species, strains, colnes, lineages, and interspecies exchanges
PublicationStaphylococci are increasingly recognized as etiological agents of many opportunistic human and animal infections, emphasizing the need for a rapid and accurate identification, even to a genotypical level of these bacteria. In the recent years, there has been a significant progress in typing and phylogenetic study of Staphylococcus species. Here, we describe molecular methods used in taxonomy as well as staphylococci characterization....
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Influence of Superparamagnetism on Exchange Anisotropy at CoO/[Co/Pd] Interfaces
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Forecasting of currency exchange rates using artificial neural networks
PublicationW rozdziale tym autor przedstawił wyniki swoich badań nad wykorzystaniem sztucznych sieci neuronowych do prognozowania kursu walut (na przykładzie pary walutowej PLN-USD).Głównym celem badań było porównanie skuteczności przewidywania kursu złotówki w latach 1997 - 2005 przy pomocy różnych rodzajów sieci neuronowych.
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Sustainable Investing. Socio-Economic Impacts of Exchange-Traded Funds
PublicationSustainable Investing: Socio-Economic Impacts of Exchange-Traded Funds examines the social and economic effects of sustainable investing ETFs and their impacts on the global financial system. The book presents the key issues with regard to sustainable investing, discussing exchange-traded funds mechanisms and categories in comparison to competing investment funds. The book outlines the theoretical determinants of ETF markets development...
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Dynamic characteristics of the proton exchange membrane fuel cell module
PublicationThe paper describes a fuel cell based system and its performance. The system is based on two fuel cell units, DC/DC converter, DC/AC inverter, microprocessor control unit, load unit, bottled hydrogen supply system and a set of measurement instruments. In the study presented in the paper a dynamic response of the proton exchange membrane (PEM) fuel cell system to unit step change load as well as to periodical load changing cycles...
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Sustainable investing exchange-traded funds: US and European market
PublicationThe key aim of the paper is to examine the diffusion of the sustainable investing exchange-traded funds (ETFs) on the European and US ETFs markets, with the special focus on the market shares of sustainable investing and conventional funds. The model of diffusion of innovation (logistic growth model) is applied. Monthly data on the assets of ETFs in the time period of 2006-2017 are used. Increasing assets of sustainable investing...
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Dynamics of Changes in The Urban Space
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The Effectiveness of Operations Implementing Changes
PublicationW niniejszym rozdziale zdefiniowano pojęcie efektywności zmian organizacyjnych. Scharakteryzowano również składowe elementy efektywności, jakimi są skuteczność, korzystność i ekonomiczność. Pokazano również miejsce oceny efektywności zmian w procesie realizacji przekształceń. Przedstawiono również model oceny efektywności zmian procesu planowania i sterowania umożliwiający ocenę skuteczności, korzystności i ekonomiczności zmian.
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Enviroment of Polish democratisation changes
PublicationW 1989 r. zapoczątkowany został w krajach Europy Środkowo-Wschodniej proces demokratyzacji. Demokratyzacja oznacza zmianę systemu społecznego w kierunku ideałów i instytucji zakorzenionych w krajach Europy Zachodniej, USA i Kanady opierających się m.in. o zasady: 1. Suwerenności narodu; 2. Republikańskiej formy państwa; 3. Poszanowaniu zasad państwa prawa; 4. Reprezentacji politycznej; 5. Podziału władzy i równoważenia się władz;...
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Management of changes in software engineering
PublicationPraca zawiera rozdział poświecony problematyce budowy systemów z bazami wiedzy dla wspomagania procesów zarządzania. W rozdziale tym przedstawiono metody budowy systemów dla potrzeb zarządzania koncentrując uwagę na systemach opartych na wiedzy. Następnie omówiono możliwości zastosowania teorii zbiorów rozmytych do modelowania wiedzy. Na zakończenie przedstawiono przykład wykorzystania zbiorów rozmytych i systemów opartych na wiedzy...
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Омонимическая общность (на примере польского и русского языков) [The homonymic community of the Finnish and Russian Languages]
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Challenges of Comparing Marine Microbiome Community Composition Data Provided by Different Commercial Laboratories and Classification Databases
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Diversity and community composition of pico- and nanoplanktonic protists in the Vistula River estuary (Gulf of Gdańsk, Baltic Sea)
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Microbial Diversity in Deep-Subsurface Hot Brines of Northwest Poland: from Community Structure to Isolate Characteristics
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Whirling system of water exchangein breeding pools
PublicationTo secure the proper conditions of life for sea mammals existing in closed systems one has to maintain the character of the breeding basins (i.e. shape, dimensions, facing of walls and bottom, quality and motion of water) as natural as possible. An appropriate system of water exchange plays a very important role here. A full renewal of water is time-consuming, expensive and troublesome, so can be made only periodically, and should...
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Plate heat exchanger with porous structure for potential use in ORC system
PublicationThe experimental analysis of passive heat transfer intensification in the case of plate heat exchanger has been carried out. The passive intensification was obtained by a modification of the heat transfer surface, which was covered by a metallic porous microlayer. The experiment was accomplished in two stages. In the first stage the commercial stainless steel gasketed plate heat exchanger was investigated, while in the second one...
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Plate heat exchanger with porous structure for potential use in ORC system
PublicationThe experimental analysis of passive heat transfer intensification in the case of plate heat exchanger has been carried out. The passive intensification was obtained by a modification of the heat transfer surface, which was covered by a metallic porous microlayer. The experiment was accomplished in two stages. In the first stage the commercial stainless steel gasketed plate heat exchanger was investigated, while in the second one...
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EFFECT OF NANOFLUID CONCENTRATION ON TWO-PHASE THERMOSYPHON HEAT EXCHANGER PERFORMANCE
PublicationAn approach – relaying on application of nanofluid as a working fluid, to improve performance of the two-phase thermosyphon heat exchanger (TPTHEx) has been proposed. The prototype heat exchanger consists of two horizontal cylindrical vessels connected by two risers and a downcomer. Tube bundles placed in the lower and upper cylinders work as an evaporator and a condenser, respectively. Distilled water and nanofluid water-Al2O3...
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Heat transfer intensification by enlarged surface roughness in the plate heat exchanger
PublicationIn the paper an experimental analysis of passive heat transfer intensification technique employed in the case of the plate heat exchanger is presented. The passive intensification was obtained by a modification of the heat transfer surface. The roughness of surface was increased by a use of glass micro-beads. Single-phase convective heat transfer in the water-water system was studied. The experiment was accomplished in two stages....
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Effect of surface roughness on thermal-hydraulic characteristics of plate heat exchanger
PublicationIn the paper the experimental analysis of passive heat transfer intensification in the case of modeled plate heat exchanger is conducted. The plate heat exchanger is chosen for the analysis because this kind of heat exchangers could be prospectively applied in the ORC systems, however other areas or application are equally possible. The experimental setup was assembled at the Department of Energy and Industrial Apparatus of Gdansk...
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CAPABILITY OF IDENTIFYING AND PREDICTING THE TECHNICAL CONDITION OF PLATE HEAT EXCHANGERS IN OPERATION
PublicationThe paper presents a test stand for plate heat exchangers, allowing to identify the technical condition and to predict durability of the heat exchangers used aboard the sea-going ships: ”Oceanograf”, ”Władysław Orkan”and a passenger-car ferry, under the condition that they are of the same type and manufactured by the same company. In the first part three different installations with plate heat exchangers in the engine rooms...
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Microjet technology as a perspective intensification method for high performance heat exchangers
PublicationIn the paper two oryginal designs of compact heat exchangers with intensification effect produced by microjets are presented. The technology of microjets manufacturing is an "inhouse" patented design. The idea of such heat exchanger is shown together with the flow and thermal characteristics of the prototypes. The results of performer measurements are satisfactory and encourage for further research of the original designs.