• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 24
  • 12
  • 7
  • 5
  • 4
  • 4
  • 3
  • 2
  • 1
  • Tagged with
  • 64
  • 9
  • 8
  • 7
  • 7
  • 6
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Turističko-ekološka studija doline Lima / Tourist and Ecological Study of the River Lim Valley

Dragović Ranko 25 September 2003 (has links)
<p>Dolina Lima i Polimlje predstavljaju složenu prostornu celinu u kojoj se prepliću različiti prirodni i antropogeni procesi. Analiza elemenata prirodne i sociokulturne sredine, njihovo turističko-ekolo&scaron;ko vrednovanje i objedinjavanje treba da pokažu svrsishodnost ulaganja u turizam i ekologiju Polimlja. Tema doktorske disertacije postavljena je tako da se kroz trinaest komplementarnih poglavlja dođe do projektovanog cilja o mogućnostima razvoja pojedinih vrsta ekoturizma. Prikaz objedinjenih sadržaja u određenom obimu doprinosi boljem poznavanju Polimlja i omogućava lak&scaron;i pristup operativnom delu turističkog planiranja u uslovima ekolo&scaron;ke i turističke održivosti. Takva konstatacija proističe iz utvrđenih vrednosti dobijenih analizom parametara kvaliteta životne sredine i sociokulturne ba&scaron;tine. Na osnovu dobijenih vrednosti izveden je zaključak da turizam u ekolo&scaron;kom ambijentu Polimlja s obzirom na kvalitet prirodnih elemenata može postati dominantna delatnost i pored negativih iskustava u oblasti životne sredine iz druge polovine dvadesetog veka.</p> / <p>The valley of the river Lim and Polimlje represent a complex regional entity in which different natural and antropogenic processes interact. Analysis of elements of the natural and socio-cultural environment, their tourist-ecological valorization and combination should show the appropriateness of investing in the tourism and ecology of Polimlje. The theme of this Ph.D. thesis is defined in such a way that through thirteen complementary chapters it arrives at the projected target about the possibillities of the development of some types of eco tourism. Presentation of the combined content to a certain degree contributes to a better knowledge of Polimlje and enables easier access to the operative part of tourist planning in conditions of ecological and tourist maintenance. Such a conclusion is the result of established values obtained by analysis of the quality of the environment and the socio-cultural heritage. Based on the values obtained it may be concluded that tourism in the ecological environment of Polimlje, having in mind the quality of natural elements, could become a dominant activity regardless of negative experiences in the environmental field in the second half of the twentieth century.</p>
42

Synthetic Functionalization of Colloidal Lignin Particles for Wood Adhesive Applications / Syntetisk funktionalisering av kolloidala Lignin-partiklar förvedhäftande applikationer

Alexander Deen, Fusi January 2020 (has links)
Functionalizable spherical colloidal lignin particles (CLPs) represent a valuable asset for the valorization of lignin side-streams from the pulp industry. The spherical structure allows for the circumvention of the heterogeneous and poorly dispersible structure of the biopolymer. However, organic solvents and alkaline media degrade the particle structure and dissolve the polymers due to their chemical nature and solubility. The solvents will alter the aggregated polymers into irregular shapes that would correspond to inconsistent physicochemical properties. Then, the material will become unusable for advanced material applications, namely wood adhesives. In this study, a replicable process to yield pH ca. 12 stable CLPs for wood adhesives or further functionalization for other advanced material applications was developed and optimized. Lignin was functionalized with cross-linkers, glyoxal or formaldehyde, and selfassembled into spherical structures in the micro emulsification of the organic solution. The formed colloids were partially rotary evaporated to retain organic solvents within the colloidal structures, and then be cured at 73-76 °C until pH stable and further functionalized for advanced material applications. The functionalization with glyoxal was pursued further for its possibly increased reactivity and the health concerns associated with formaldehyde. The process requires the addition of glyoxal to lignin in an acidic organi cmedia at ambient temperature, and the solution to react at 64 °C. Glyoxal is likely added to the polymer structure in its hydrated and dimerized form, and its attachment to lignin should be analyzed through the behavior of glyoxal in different media. The formed colloids were rotary evaporated to an organic solvent content of 60 wt. % of the spheres to allow the occurrence of the curing reaction. These materials were finally cured by thermosetting them at 73-76 °C until pH stable. The particles can be cured with base-catalysis through the controlled addition of the base NaOH(aq). However, the mode and rate of addition of the catalyst are critically important for a nondegradative infusion of a base into solvent present ot removed particles without morphological changes. Further procedural improvement and larger batches are necessary to conduct CLP adhesive experiments. / Funktionaliserbara sfäriska kolloidala ligninpartiklar (CLP) är en värdefull tillgång för valorisering av ligninsidoströmmar från massaindustrin. Den sfäriska strukturen reducerar effekten av den heterogena och dåligt dispergerbara biopolymeren. Organiska lösningsmedel och alkaliska medier försämrar emellertid partikelstrukturen och löser upp polymererna på grund av deras kemiska natur och löslighet. Lösningsmedel kommer att resultera i att de aggregerade polymererna antar oregelbundna former vilket skulle resultera i inkonsistenta fysikalisk-kemiska egenskaper. Därigenom blir materialet oanvändbart för avancerade materialapplikationer, såsom t ex trälim. I denna studie, utvecklades och optimerades en reproducerbar process för att ge pH ca. 12 stabila CLP för trälim eller ytterligare funktionalisering för andra avancerade materialapplikationer. Lignin funktionaliserades med tvärbindare, glyoxal eller formaldehyd och självorganiserades till sfäriskas trukturer genom mikroemulgering av organfasen. De bildade kolloiderna indunstades delvis roterande för att bibehålla det organiska lösningsmedlet i de kolloidala strukturerna och härdades sedan vid 73-76 ° C tills pH-stabilitet och funktionaliserades ytterligare för avancerade materialapplikationer. Funktionaliseringen med glyoxal utfördes också för att reaktiviteteten och begränsa de hälsoproblem som är förknippade med formaldehyd. Förfarandet kräver tillsats av glyoxal till lignin i ett surt organiskt medium vid rumstemperatur för att sedan reageras vid 64 ° C. Glyoxal i dess hydratiserade och dimeriserade form adderas sannolikt till polymeren, och dess kemiska inbindning till lignin kan analyseras genom att undersöka glyoxal uppförande i olika medier. De bildade kolloiderna indunstades till ett organiskt lösningsmedelsinnehåll av 60 viktprocent för att möjliggöra härdning. Dessa material härdades slutligen genom värmehärdning vid 73-76 ° C tills pH var stabilt. Partiklarna kan härdas med baskatalys genom kontrollerad tillsats av basen NaOH (aq). Emellerti där sättet och tillsatshastigheten för katalysatorn kritiskt viktigt. Ytterligare processförbättringar och större satser är nödvändiga för att genomföra CLP-limexperiment.
43

Lim i skor : Vattenbaserade lim som ett mindre riskfyllt alternativ till lösningsbaserade lim

Trieb, Alicia, Lönnesjö, Jennie January 2020 (has links)
NilsonGroup presenterade uppdraget att undersöka vattenbaserade lim som alternativ till lösningsbaserade lim vid tillverkning av skor, vilket var grunden till det här arbetets ämne och avgränsningar har tagits fram. Vattenbaserade lim är ett alternativ till lösningsbaserade lim som inte är lika hälsofarligt, då lösningsmedelkan orsaka allvarliga hälsoeffekter. Enligt NilsonGroup ligger skobranschen steget efter vad det gäller hållbarhet och i nuläget saknas det en satsning på hållbarutveckling, medan andra branscher är bättre på att leta efter nya möjligheter. Det här arbetet vill lyfta fram på vilka sätt vattenbaserade lim är ett mindre riskfylltalternativ till lösningsbaserade lim och visa att skillnaderna i limfogens egenskaper inte blir så olika. Första delen av resultatet innefattar en definition av lim och limning. Fokus ligger på att reda ut vad som krävs och hur en limfog skapas med ett lim mellan två ytor, för att läsaren ska få en grundlig kunskap om det innan arbetet går in på lim i skor. Det presenteras även vilka egenskaper som är viktiga för en limfog och vilka faktorer det är som vanligtvis vägs in vid val av lim. Andra delen handlar om material, lim och limfogar i skoindustrin. Resultatet visar att det är den övre delen av skon och sulan som är den mest kritiska limfogen att skapa vid tillverkningen av en sko, samt att de mest förekommande lim som används vid skotillverkning är av polymererna polyuretan och polykloropren. De material till den övre delen av skon som främst används av NilsonGroup och generellt hela skoindustrin, är syntetiskt skinn, läder och bomull. Till en skos sula används gummi och polyuretan i störst utsträckning. Resultatet kommer fram till fem olika kombinationer av material och vattenbaserade lim som har bra potential att kunna bilda en hållbar limfog. Resultatet visar även att de egenskaper som vattenbaserade och lösningsbaserade polykloropren- och polyuretanlim ger en limfog är lika, så när det kommer till att välja mellan vattenbaserade lim och lösningsbaserade lim, så är det komponenterna i limmen och riskerna de medför som innefattar den stora skillnaden. I bilaga 1presenteras alla de mest förekommande komponenter som polyuretan- och polykloroprenlim består av, samt vilka hälsoeffekter de kan orsaka vid exponering för ämnet. / NilsonGroup presented the assignment to investigate water-borne adhesives as an alternative to solvent-borne adhesives in shoe production. This represent the purpose of this work and the limitations that have been developed. Water-borne adhesives do not pose as serious health risks as solvent-borne adhesives, mainly because of the solvent that may cause serious health risks. According to NilsonGroup, the shoe industry is a step behind in terms of sustainability and there is no investment in sustainable development. While other industries are stepping forward in terms of sustainability. The purpose of this work is to highlight waterborne adhesives as a less critical alternative to solvent-borne adhesives. And to prove that the characteristics between the two choices are not so different. The first part of this work explains adhesives and adhesive bonding. The part explains the requirements and how an adhesive joint is created from an adhesive between two different surfaces. This is necessary to get the reader to understand the basics about adhesive bonding before the work focus on adhesives in shoes. Important properties related to the adhesive joint and the common factors when choosing adhesives is also a part of this work. Second part of this work deals with material, adhesives and adhesive joints in the shoe industry. The upper part of the shoe and sole bonding process is the most critical joint in the shoe and the most common adhesives in the shoe industry is made of polyurethane and polychloroprene polymers. Some common materials used in the upper part of shoes made by NilsonGroup, and the shoe industry overall, are synthetic leather, leather and cotton. The sole is usually made of rubber or polyurethane. The result presents five different combinations of material and waterborne adhesives that may have the potential to produce a durable joint. The result shows that the properties related to waterborne and solvent-borne adhesives are equivalent. When choosing type of adhesive, the components in the adhesives and the health risk they cause, makes up the big difference. Appendix 1 presents common components in polyurethane and polychloroprene adhesives along with health risks that they may cause when exposed.
44

Codes transcriptionnels et expression du gène du récepteur de la GnRH au cours du développement et chez l'adulte

Schang, Anne-Laure 01 June 2011 (has links) (PDF)
Le récepteur hypophysaire de la GnRH (RGnRH) joue un rôle crucial dans le contrôle de la fonctionde reproduction. Dans le promoteur distal du Rgnrh, j'ai caractérisé un élément de réponsebifonctionnel répondant aux protéines LIM à homéodomaine ISL1/LHX3 et à GATA2. D'autre part,deux motifs TAAT situés dans la région plus proximale confèrent à ce gène la capacité de répondreaux facteurs Paired-like PROP1 et OTX2. Tous ces facteurs, exprimés précocement au cours del'ontogenèse hypophysaire, pourraient participer à l'émergence de l'expression du Rgnrh. Hors del'hypophyse, j'ai découvert que le Rgnrh est exprimé au cours du développement postnatal dansl'hippocampe de rat, où il module la plasticité synaptique. Par ailleurs, j'ai identifié deux nouveauxsites d'expression, la rétine et la glande pinéale. Ces résultats mettent en lumière l'importancefonctionnelle de ce récepteur et de son ligand et les rôles multiples qu'il ont acquis au cours del'évolution des Vertébrés.
45

Intelektinės tiesiaeigės pavaros tyrimas / Research on the Intelligent Linear Drive

Jenkinas, Pavelas 17 June 2011 (has links)
Baigiamojo magistro darbo tiriamasis objektas – intelektinė tiesiaeigė elektros pavara. Tyrimo tikslas – ištirti tiesiaeigę elektros pavarą, valdoma neraiškiuoju reguliatoriumi. Uždaviniai – sudaryti intelektinės tiesiaeigės pavaros kompiuterinį modelį gauti ir ištirti imitacijos rezultatus, juos palyginti su tokia pačia PI reguliatoriumi valdoma pavara. Literatūros analizės dalyje išnagrinėtas neraiškiosios logikos panaudojimas valdant elektros pavaras. Pateikiami straipsniai, kuriose aprašomos elektros pavarų valdymo galimybės panaudojant neraiškiosios logikos reguliatorius. Teorinėje dalyje išnagrinėjamos tiesiaeigės pavaros, pateikiamos jų taikymo apžvalga ir panaudojimo galimybės. Taip pat išanalizuojamos neraiškiosios valdymo sistemos, jų sudarymo principai ir panaudojimas reguliatoriuose. Aptariami tiesiaeigių elektros pavarų valdymo būdai. Tiriamojoje dalyje sukurtas tiesiaeigės pavaros kompiuterinis modelis, suprojektuotas neraiškusis reguliatorius, gauti imitacijos rezultatai. Rezultatams palyginti sudarytas pavaros modelis naudojant PI reguliatorių. Gauti rezultatai ištirti ir palyginti. Išnagrinėjus tiesiaeigės asinchroninės pavaros imitavimo rezultatus pateikiamos išvados ir pasiūlymai. Darbą sudaro 7-ios dalys: įvadas, literatūros analizė, tyrimo tikslas ir uždaviniai, teorinė dalis, tiriamoji dalis, apibendrinančioji dalis, naudotos literatūros šaltinių sąrašas. Darbo apimtis – 65 psl. teksto be priedų, 43 iliustr., 2 lent., 37 bibliografiniai šaltiniai, iš jų... [toliau žr. visą tekstą] / Research subject of master thesis is intelligent linear electric drive. Objective of the study - to investigate linear electric actuator, controlled with Fuzzy controller. Tasks - create computer model of intellectual linear drive, to investigate the simulation results and compare them with the same drive which controlled with PI controller. In the literary analysis part usage of Fuzzy logic in the electric drives control has been examined. Articles with description of the electric drive control features using Fuzzy logic controller have been given. In the theoretical part the linear actuators are analyzed, the review of the application and their usability was given. Also are analyzed Fuzzy control systems, their creation principles and usage in the regulators. The linear electric drive control methods are discussed. In the research part computer model of the linear drive has developed, designed Fuzzy controller, analyzed simulation results. For results comparing the model with PI controller has designed. The results obtained are examined and compared. After examination results of the linear induction drive simulation the conclusions and recommendations are given. The work consists of seven parts: introduction, literature review, the study aims and objectives, the theoretical part, research, generalization and used references. Thesis volume - 65 pages text without appendixes, 43 pictures, 2 tables, 37 bibliographical sources, including internet links 10. Appendixes are... [to full text]
46

Pellet Power

Vice President Research, Office of the January 2009 (has links)
Wood pellets are offering opportunities for a cleaner-burning biofuel but major concerns are overshadowing their potential. Tony Bi and UBC’s Clean Energy Research Centre are engineering solutions.
47

Tiesiaeigių asinchroninių variklių nesimetrinių režimų tyrimas / Investigation Into Non-Symmetrical Modes Of Linear Induction Motors

Lisauskas, Saulius 11 January 2007 (has links)
Linear induction motors are applied in equipments with different requirements set up to the controlled motion parameters. Investigation of motoring and breaking modes remains the relevant problem nowadays. The scientific novelty is based on analysis of non-symmetrical operation modes of linear induction motor at supplying it by a voltage source, developing a generalized model of motoring and breaking dynamic modes and analyzing influence of linear motor windings connection way and control parameters on dynamic breaking characteristics. The coordinate transformations of linear induction motors dynamic models, based on rotational motor with assumptions valid for low speed motor and multi-pole motor, are considered. Mathematical and computer models to investigate symmetrical dynamic modes of linear induction drives are presented. Generalized model to investigate non-symmetrical dynamics modes is elaborated. The results of simulation are presented by dependences on the main variables in the time domain, and dependences on both constructional and control parameters that give possibility to optimize constructional parameters of motors.
48

Tiesiaeigių asinchroninių variklių nesimetrinių režimų tyrimas / Investigation Into Non-Symmetrical Modes Of Linear Induction Motors

Lisauskas, Saulius 17 January 2007 (has links)
Linear induction motors are applied in equipments with different requirements set up to the controlled motion parameters. Investigation of motoring and breaking modes remains the relevant problem nowadays. The scientific novelty is based on analysis of non-symmetrical operation modes of linear induction motor at supplying it by a voltage source, developing a generalized model of motoring and breaking dynamic modes and analyzing influence of linear motor windings connection way and control parameters on dynamic breaking characteristics. The coordinate transformations of linear induction motors dynamic models, based on rotational motor with assumptions valid for low speed motor and multi-pole motor, are considered. Mathematical and computer models to investigate symmetrical dynamic modes of linear induction drives are presented. Generalized model to investigate non-symmetrical dynamics modes is elaborated. The results of simulation are presented by dependences on the main variables in the time domain, and dependences on both constructional and control parameters that give possibility to optimize constructional parameters of motors.
49

Proračun intenziteta erozije zemljišta u Polimlju (Crna Gora i Srbija) i Širindareh slivu (Iran) korišćenjem WIntErO modela / Calculation of soil erosion intensity in Polimlje (Montenegro and Serbia) and Širindareh basin (Iran) using the WIntErO model

Vujačić Duško 10 April 2019 (has links)
<p>Predmet&nbsp; ovog&nbsp; rada&nbsp; predstavlja&nbsp; geografski prostor&nbsp; sliva&nbsp; Lima&nbsp; od&nbsp; Plavskog&nbsp; jezera&nbsp; do&nbsp; brane&nbsp; HE &#39;&#39;Potpeć&#39;&#39;,&nbsp; kao&nbsp; jedne&nbsp; prostorno-funkcionalne&nbsp; cjeline,koji&nbsp; se&nbsp; prostire&nbsp; na&nbsp; teritorijama&nbsp; država&nbsp; Crne&nbsp; Gore (2334&nbsp; km <sup>2</sup>),&nbsp; Srbije&nbsp; (2407,7&nbsp; km <sup>2</sup> )&nbsp; i&nbsp; Albanije&nbsp; (115,5<br />km <sup>2 </sup>) i &Scaron;irindareh sliv na NE Irana.Kori&scaron;ćenjem&nbsp; računarsko-grafičkog&nbsp; metoda<br />programa&nbsp; &quot;WintErO&quot;,&nbsp; u&nbsp; proučavanju&nbsp; oticanja&nbsp; i intenziteta&nbsp; erozije,&nbsp; vrijednosti&nbsp; povr&scaron;ina&nbsp; (povr&scaron;ina slivova,&nbsp; povr&scaron;ina&nbsp; između&nbsp; izohipsi&nbsp; i&nbsp; sl.)&nbsp; i&nbsp; dužina,&nbsp; tj.rastojanja sa karte (dužina glavnog vodotoka, dužina linije vododjelnice i sl.) veoma precizno je obrađena,<br />&scaron;to&nbsp; nije&nbsp; uvijek&nbsp; bio&nbsp; slučaj&nbsp; kod&nbsp; primjene&nbsp; mehaničkih instrumenata,&nbsp; planimetara&nbsp; i&nbsp; kurvimetra.&nbsp; Obradom dobijenih&nbsp; fizičko-geografskih&nbsp; inputa,&nbsp; nakon&nbsp; unosa podataka,&nbsp; dobijeni&nbsp; su&nbsp; rezultati.&nbsp; Detaljan&nbsp; prikaz&nbsp; ove računarsko&nbsp; grafičke&nbsp; metode&nbsp; predstavljen&nbsp; je&nbsp; u rezultatima ove doktorske disertacije.<br />Dio istraživanja ovog doktorskog rada obavljen je na području sjeveroistoka Irana, u slivu &Scaron;irindareh. Oko 100 miliona hektara iranske teritorije je izloženo eroziji&nbsp; ili&nbsp; drugim&nbsp; hemijskih&nbsp; i&nbsp; fizičkih&nbsp; degradacija.Erozija&nbsp; vodom&nbsp; ugoržava&nbsp; velike&nbsp; povr&scaron;ine&nbsp; u&nbsp; Iranu,<br />uni&scaron;tavajući pri tom plodna poljoprivredna zemlji&scaron;ta. Skoro&nbsp; 35&nbsp; miliona&nbsp; hektara&nbsp; Irana&nbsp; je&nbsp; pod&nbsp; uticajem različitih&nbsp; vrsta&nbsp; erozije&nbsp; vodom.&nbsp; Ova&nbsp; činjenica&nbsp; je&nbsp; bila povod i izazov da se i ova istraživanja dijelom osvrnu na&nbsp; ovu&nbsp; problematiku&nbsp; u&nbsp; Iranu,&nbsp; testirajući&nbsp; pri&nbsp; tom<br />novopripemljeni&nbsp; model&nbsp; WIntErO&nbsp; na&nbsp; jednom&nbsp; od slivova u Iranu.</p> / <p>The subject of this paper is the&nbsp; geographical area of&nbsp; the Lim&nbsp; Basin&nbsp; from&nbsp; Plav&nbsp; Lake&nbsp; to&nbsp; the&nbsp; dam&nbsp; &quot;Potpeć&quot;,&nbsp; as&nbsp; a spatial-functional&nbsp; unit,&nbsp; spreading&nbsp; in&nbsp; the&nbsp; territories&nbsp; of&nbsp; the countries&nbsp; of&nbsp; Montenegro&nbsp; (2,334&nbsp; km2),&nbsp; Serbia&nbsp; (2407,7 km2)&nbsp; and&nbsp; Albania&nbsp; 115.5&nbsp; km2).&nbsp; In&nbsp; mathematicalgeographical terms,&nbsp; the research area is between 42 &deg; 37 &#39;and 43 &deg; 30&#39; north latitude and 17 &deg; 10 &#39;and 17 &deg; 23&#39; east longitude.&nbsp; The&nbsp; research&nbsp; area&nbsp; is&nbsp; located&nbsp; in&nbsp; the&nbsp; north&nbsp; of Albania,&nbsp; east&nbsp; and&nbsp; north-east&nbsp; of&nbsp; Montenegro,&nbsp; and&nbsp; in&nbsp; the southwest of Serbia. Using the computer-graphic&nbsp; method of the &quot;WintErO&quot; program, in the study of the erosion and intensity&nbsp; of&nbsp; erosion,&nbsp; the&nbsp; surface&nbsp; values&nbsp; (surface&nbsp; of&nbsp; the basins,&nbsp; the&nbsp; area&nbsp; between&nbsp; isohipins,&nbsp; etc.)&nbsp; and&nbsp; length,&nbsp; The distance&nbsp; from&nbsp; the&nbsp; map&nbsp; (the&nbsp; length&nbsp; of&nbsp; the&nbsp; main watercourse, the length of the line of the water line, etc.) is&nbsp; very&nbsp; precisely&nbsp; processed,&nbsp; which&nbsp; was&nbsp; not&nbsp; always&nbsp; the case with the use of mechanical instruments, planimeters and&nbsp; curvimeters.&nbsp; By&nbsp; obtaining&nbsp; the&nbsp; obtained&nbsp; physicalgeographic&nbsp; inputs,&nbsp; after&nbsp; entering&nbsp; the&nbsp; data,&nbsp; results&nbsp; were obtained.&nbsp; A&nbsp; detailed&nbsp; view&nbsp; of&nbsp; this&nbsp; computer&nbsp; graphic method&nbsp; is&nbsp; presented&nbsp; in&nbsp; the&nbsp; results&nbsp; of&nbsp; this&nbsp; doctoral dissertation.&nbsp; Part&nbsp; of&nbsp; the&nbsp; research&nbsp; of&nbsp; this&nbsp; doctoral&nbsp; thesis was&nbsp; done&nbsp; in&nbsp; the&nbsp; area&nbsp; of&nbsp; the&nbsp; northeast&nbsp; of&nbsp; Iran,&nbsp; in&nbsp; the Shirindareh basin. About 100 million hectares of Iranian territory are exposed to erosion or other types of chemical and&nbsp; physical&nbsp; degradation&nbsp; (Kheirodin,&nbsp; 2016).&nbsp; Erosion&nbsp; by water&nbsp; entangles&nbsp; large&nbsp; areas&nbsp; in&nbsp; Iran,&nbsp; destroying&nbsp; fertile agricultural&nbsp; land&nbsp; (Sadeghi,&nbsp; 2017).&nbsp; Almost&nbsp; 35&nbsp; million hectares of Iran&nbsp; are under the influence of various types of&nbsp; water&nbsp; erosion&nbsp; (Zakerinejad&nbsp; and&nbsp; Maerker,&nbsp; 2015).&nbsp; This fact&nbsp; was&nbsp; also&nbsp; a&nbsp; cause&nbsp; and&nbsp; challenge&nbsp; for&nbsp; the&nbsp; research&nbsp; to partly look at this issue in Iran, testing the new WIntErO model on one of the basins in Iran.</p>
50

Korslimmat trä : Studie om delaminering vid brandexponering för olika brandskyddsbehandlingar

Engvall, Vera, Zanasson, Zinar January 2022 (has links)
Purpose: This work is based on the problem with the product cross-laminated timber and its properties in the event of fire. The reason for the problem is the glue used in the product and the lack of requirements for adhesion at high temperatures. Due to this, there is a risk of delamination in the event of a fire, i.e. that the wooden slats that constitute the largest component in the CLT wood fall off during the course of the fire and contribute to extra energy. Method: The work is built up of two different methods, first a literature study and then an experiment. The literature study focuses on the National Board of Housing, Building and Planning's building regulations, the production of cross-laminated timber and what happens in the event of a fire. The experiment was carried out at Fågelbacken in Västerås, where help from the rescue service was available. The informative part of the report begins with a subject reference framework where the first part consists of information about the National Board of Housing, Building and Planning's requirements and ordinances that are based on the Planning and Building Act and the Planning and Building Ordinance. This study describes the experiment, everything from the application of the fire protection treatment to the design of the fire test. The materials included in the fire test are described and any certifications they hold are mentioned. The results section presents the results of the literature study and the fire test. Results: The four pieces of wood showed different results after fire, as three out of four showed cracks between the slats on the fire-affected surface. No piece of wood delaminated or had loose slats, however, the cracks are interpreted as meaning that the glue did not withstand the temperature that the fire generated, and melted. The depths of the carbon layer, on the other hand, were significantly protected by the fire protection treatment as there was a maximum difference of 7 mm between one of the fire protection-treated pieces of wood and the untreated piece of wood. The burning time of the fuel pool varied. The course of fire for the pieces that were treated with fire protection was strong with large flames and large, black smoke pillars. Conclusion: The conclusion of the thesis is that the fire protection treatment has a good effect on the depth of the carbon layer, which delays the risk of delamination. The fire protection treatment also has a good effect on the adhesive in some of the cases when no or few cracks between the slats were seen.

Page generated in 0.0401 seconds