1,720,977 research outputs found
Techno-economic analysis of integrating a water-to-water heat pump into the district heating system of Zagreb
No full textOvaj rad istražuje mogućnost integracije dizalice topline voda-voda u centralizirani toplinski sustav grada Zagreba s ciljem povećanja energetske učinkovitosti i smanjenja emisija CO₂. Analizira se korištenje rijeke Save kao izvora topline, pri čemu su razmatrane tehničke karakteristike sustava, sezonske varijacije temperature vode i utjecaj na koeficijent grijanja (COP). Također je provedena ekonomska analiza koja uspoređuje troškove implementacije s potencijalnim financijskim uštedama i tržišnim mehanizmima smanjenja emisija. Rezultati pokazuju da primjena ovog sustava može smanjiti potrošnju primarne energije i omogućiti opskrbu toplinom uz manji ekološki otisak.This study explores the potential integration of a water-to-water heat pump into the centralized heating system of the city of Zagreb, aiming to enhance energy efficiency and reduce CO₂ emissions. The use of the Sava River as a heat source is analyzed, considering the system's technical characteristics, seasonal water temperature variations, and the impact on the coefficient of performance (COP). An economic analysis was also conducted, comparing implementation costs with potential financial savings and market-based emission reduction mechanisms. The results indicate that adopting this system could decrease primary energy consumption and provide heat supply with a reduced environmental footprint
Techno-economic analysis of integrating a water-to-water heat pump into the district heating system of Zagreb
No full textOvaj rad istražuje mogućnost integracije dizalice topline voda-voda u centralizirani toplinski sustav grada Zagreba s ciljem povećanja energetske učinkovitosti i smanjenja emisija CO₂. Analizira se korištenje rijeke Save kao izvora topline, pri čemu su razmatrane tehničke karakteristike sustava, sezonske varijacije temperature vode i utjecaj na koeficijent grijanja (COP). Također je provedena ekonomska analiza koja uspoređuje troškove implementacije s potencijalnim financijskim uštedama i tržišnim mehanizmima smanjenja emisija. Rezultati pokazuju da primjena ovog sustava može smanjiti potrošnju primarne energije i omogućiti opskrbu toplinom uz manji ekološki otisak.This study explores the potential integration of a water-to-water heat pump into the centralized heating system of the city of Zagreb, aiming to enhance energy efficiency and reduce CO₂ emissions. The use of the Sava River as a heat source is analyzed, considering the system's technical characteristics, seasonal water temperature variations, and the impact on the coefficient of performance (COP). An economic analysis was also conducted, comparing implementation costs with potential financial savings and market-based emission reduction mechanisms. The results indicate that adopting this system could decrease primary energy consumption and provide heat supply with a reduced environmental footprint
Maximising of waste heat recovery of industrial regions using Total Site approach
No full textOvaj je završni zadatak vezan za projekt CARBEN. "Carbon footprint reduction and energy efficiency via development an advanced tehniques for Total Site integration" je projekt koji se provodi na Fakultetu strojarstva i brodogradnje u Zagrebu od 2014. godine teži postignućima koje će biti objašnjene u daljnjem tekstu. Cilj je bio povećati regeneraciju topline na tri odvojena mjesta korištenjem Total site metode i izračunati potencijal uštede energije i ekonomske pokazatelje štednje novca. Zadatak zadaje industrijski proces A, industrijski proces B i stambeno područje C. Svaki od njih ima više struja hlađenja i grijanja, kao i kondenzacije i isparavanja. Prvo, pomoću Pinch metode, izračun nas je doveo do minimalne topline grijanja i hlađenja uzimajući u obzir minimalnu temperaturnu razliku od 10° C. Također, izračunata je mreža izmjenjivača topline, kao i grafički prikaz mreže. Nakon toga primijenjena je Total site metoda na minimalnu potrebnu dovedenu i odvedenu toplinu, kao i izračun mreže izmjenjivača na Total siteu. Također je definiran medij preko kojeg se prenosi toplina unutar total sitea preko minimalnih površina potrebnih za provođenje topline. Koristeći dobivene i izračunate podatke izvedena je ekonomska analiza. Cilj je vidjeti razliku potrošnje između izračunate regeneracije topline u odnosu na procese bez ikakve regeneracije. Korišteni su podaci poput cijene izmjenjivača, diskontne stope, cijene površine izmjenjivača za izmjenu topline i koeficijent nelinearnosti između površine izmjenjivača i cijene po metru kvadratnom izmjenjivačke površine. Rezultati su pokazali regeneraciju od 4433 kW, s time da odvođenje topline izvana nije uopće potrebno, pošto su se vruće struje dovele na definiranu temperaturu isključivo regeneracijom, a vanjsko dovođenje topline potrebno je samo 1778,85 kW. Rezultirajuća ušteda unutar 5 godine ja 2.921.058,15 eura današnje vrijednosti novca u odnosu na procese bez regeneracije topline. Troškovi ugradnje izmjenjivača i trošak samih izmjenjivača iznosi 378.564 eura. Također je velika prednost postrojenja s regeneracijom topline niža emisija ugljičnog dioksida, što je od velike važnosti za današnji svijet. Težnja za manjim emisijama u svjetskoj politici je velika zbog sve većih utjecaja zagađivača na okoliš, te brojnih posljedica koje proizlaze iz toga.This BSc thesis assignment is tied to the project CARBEN. The 'Carbon footprint reduction and energy efficiency via development an advanced tehniques for Total Site integration' is a project which has been carried out on Faculty of mechanical engineering and naval architecture in Zagreb since 2014. The thesis has acomplished great benefits which will be explained in further text. The goal was to maximise the regeneration of heat on three seperate sites using Total site method and to calculate its potential of energy savings and economic indicators of saving money. The assignment has and industrial process A, industrial process B and residential and commercial area also known as process C. Each one of them has number of cooling and heating streams, as well as condensation and evaporation streams. Firstly, using basic Pinch method, the calculations led us to minimum hot and cold utility for minimum temperature difference of 10°C. Also, the calculations for heat exchanger network (HEN) were made, and all of the graphical apstract as well. Afterwards, the total site method was applied for these minimum hot and cold utilities, and the calculation of HEN inside the total site. Also, the intermediate utility was defined using minimum heat transfer area of the heat exchangers. Using all these calculations and obtained results, the economic analysis was made. The goal was to see what is the difference of costs for processes with regeneration an without it. The provided data such as installation of heat exchangers, money discount rate, cost of one squared meter of heat transfer surface and nonlinearity coefficient of price of the heat transfer surface was used. The results were astonishing, the regeneration acomplished is 4433kW for cold and hot utility, and only 1778,85kW of additional hot utility was needed and no cold utility at all because all hot streams were cooled down via regeneration. The result was 2.921.058,15 euros of present value money of savings in 5 years compared with processes without regeneration. The expenses for installation and revamp were included and they were around 378.564 euros. Also, the benefits beside capital profits are lower carbon emissions, which are of great importance in todays world
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Energy efficiency and carbon footprint reduction for Croatian regions by Total Site integration
No full textAppropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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