• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 86
  • 34
  • 34
  • 15
  • 13
  • 11
  • 6
  • 6
  • 5
  • 3
  • 2
  • 2
  • 2
  • 2
  • 1
  • Tagged with
  • 254
  • 31
  • 26
  • 22
  • 21
  • 20
  • 18
  • 16
  • 15
  • 15
  • 15
  • 14
  • 13
  • 13
  • 13
  • 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.
71

How does industrial symbiosis influence environmental performance?

Onita, John January 2006 (has links)
<p>A collaborative approach to industry-environment issues is acknowledged as a key aspect of sustainable development. Sincerely, resource sharing among firms offers the potential to increase stability of operations, especially in supply-constrained areas, by ensuring that access to important inputs such as water, energy and raw materials are guaranteed. Industrial Symbiosis (IS), a sub-field of Industrial Ecology, is primarily concerned with the cyclical flow of resources through networks of industrial units as a means of cooperatively approaching environmentally sustainable industrial activity. In line with this principle, a critical assessment of the change in environmental performance brought about by industrial symbiosis (IS) was conducted in nineteen selected eco-industrial park case studies identified in all regions of the world with the exception of the African continent. Case study selection criteria were based on models of eco-industrial parks proposed by Chertow (2000). A description of the type of material exchanges that go on in each case study was carried out which revealed evidence of implemented synergies in respective case studies. A comparative assessment of cross-case patterns which is a semi-quantitative matrix used to quantify the degree of environmental performance showed that there was a clear evidence of improved environmental performance among respective case studies investigated where water, energy and material flows served as indicators. Results obtained from the study showed a common pattern of industrial presence in respective case studies reflecting the occurrence of heavy process industries such as oil refineries, cement industries, petrochemical industries, and steel industries. The principle of “anchor tenant” proposed by some experts in the field of industrial ecology was strongly supported by the obtained results. Symbiotic cooperation among participating firms in respective case studies were mainly on areas like cogeneration, re-use of materials, recycling and wastewater treatment and re-use.</p>
72

Ice, wood and rocks : regulating elements in riverine ecosystems

Engström, Johanna January 2010 (has links)
Riparian ecosystems are of great importance in the landscape, connecting landscape elements longitudinally and laterally and often encompassing sharp environmental gradients in ecological processes and communities. They are influenced by fluvial disturbances such as flooding, erosion and sediment deposition, which create dynamic and spatially heterogeneous habitats that support a high diversity of species. Riverine ecosystems belong among the world’s most threatened systems. In rivers throughout the world, human alterations to fluvial disturbance regimes have resulted in degraded ecosystems and species loss. For example, in Sweden, watercourses of all sizes have been channelized to facilitate timber floating, but in the last 10–20 years the impacts in some of the affected rivers have been reduced by restoration actions. The objectives of this thesis are to evaluate how riverine ecosystems in general, with specific focus on riparian communities, are affected by (1) restoration of channelized reaches by boulder replacement, (2) ice formation, and (3) restoration of in-stream wood abundance in the stream channel. Objective (1) was assessed by quantifying the retention of plant propagules in channelized and restored stream reaches and by evaluating effects on riparian plant and bryophyte communities in disconnected and re-opened side channels. Retention of plant propagule mimics was highest at low flows and in sites where boulders and large wood had been replaced into the channel. Propagules are however unlikely to establish unless they can be further dispersed during subsequent spring high flows to higher riparian elevations suitable for establishment. Thus, immigration to new suitable sites may occur stepwise. Our study demonstrates that restoration of channel complexity through replacement of boulders and wood can enhance retention of plant propagules, but also highlights the importance of understanding how restoration effects vary with flow. We detected no differences in riparian diversity between re-opened and disconnected side channels, but we did observe significant differences in species composition of both vascular plant and bryophyte communities. Disconnected sites had more floodplain species, whereas restored sites had more species characteristic of upland forest. This suggests that the reopening of side channels resulted in increased water levels, resulting in new riparian zones developing in former upland areas, but that the characteristic floodplain communities have not had time to develop in response to the restored fluvial regime. Objective (2) was approached by evaluating the effect of both natural anchor ice formation and experimentally created ice in the riparian zone. Riparian plant species richness and evenness proved to be higher in plots affected by anchor ice. Plants with their over-wintering organs above the ice sheet suffered from the treatment but the overall species richness increased in ice-treated plots. Objective (3) was evaluated by studying wood recruitment and movement, channel hydraulics, propagule retention and fish abundance in streams restored with large wood. Only one stream experienced reduced velocities after large wood addition. The large size and reduced velocity were probably also the reasons why this stream proved to be the best one in trapping natural, drifting wood. Increased retention and decreased mechanical fragmentation in large wood sites will lead to decreased loss of detritus from the site and therefore higher availability of coarse particulate organic matter which can result in more species rich shredder communities. Our study did not show that the occurrence of large wood had an important role in controlling density or biomass of brown trout.
73

Affärsrelationer inom ett köpcenter / Business relationships within a shopping centre

Emmesjö, Martin, Attås, Jakob January 2013 (has links)
Aktuell forskning indikerar att antalet köpcenter växer för varje år som går, vilket grundar sig i att detaljhandelsindustrin under de senaste decennierna expanderat allt mer. Mycket av köpcentrens succé har att göra med dess bekvämlighetsfaktor, vilket resulterat i att denna detaljhandelsform snabbt hittat hem hos gemene man. Detta eftersom de erbjuder ett smidigt och effektivt shoppingalternativ jämfört med den klassiska gatan kantad av butiker. Dess placering tenderar även att vara lättillgänglig från både bostad och jobb vilket ökar attraktionsvärdet för köpcentret som i sin tur också har att göra med den ökande betydelsen av en välbalanserad hyresgästmix. Det vill säga den sammansättning av butiker som gallerian har. Butiker som i sin tur lever på de kunder som besöker köpcentret och som blivit allt svårare att locka till sig i dagens konkurrens, ledd av näthandeln. En förutsättning för att möjliggöra detta är att köpcentrumledningen försöker uppnå ett ömsesidigt samarbete med sina hyresgäster för att skapa synergieffekter mellan de olika delarna inom köpcentret. Detta lägger än mer tyngd på ledningen för ett köpcentrums relation till hyresgästerna. Därför syftar denna studie till att undersöka vilka faktorer som spelar in i affärsrelationen mellan köpcentrumledningen och hyresgästerna inom ett köpcenter och utröna hyresgästernas beroende av varandra. För att uppfylla syftet har en enkätundersökning genomförts. Denna har distribuerats till köpcentrena MittiCity och Galleria Duvan som båda är belägna i Karlstad. Resultatet från undersökningen indikerar att deltagarna värdesätter en levande kommunikation med centrumledningen och att de har möjlighet att vara med och påverka vid centrala beslut inom köpcentret. Däremot visar utfallet att respondenterna är oeniga när det gäller centrumledningens flexibilitet och strävan efter ett långsiktigt hyresförhållande. I fråga om hyresgästernas inbördes beroende av varandra pekar resultatet på att deltagarna ser värdet i att köpcentret innehar ankarhyresgäster. Dessutom framgår att de erfar att både deras egen butik och deras grannbutiker gynnas av de kunder som respektive butik attraherar. Däremot visar resultatet att merparten av respondenterna upplever det som negativt om grannbutikerna har snarlika produkter. / Current research indicates that the number of shopping centers is growing each year that passes, which in turn is based upon that the retail industry during recent decades has expanded without a foreseeable end in sight. Much of the shopping mall´s success has to do with its convenience factor. This has resulted in that this form of retail establishment quickly found a home among the general public. This is because they provide a convenient and efficient shopping alternative compared to the classic street based shops. Furthermore its location also tends to be easily accessible from both housing and jobs, which also increases the general appeal of the mall. Another factor that applies to mall appeal is the increasing importance of a balanced tenant mix. That is, the composition of the stores that occupies the mall. Store´s, which in turn depends on the customers who visits the mall. Attracting these customers has become a feat that has grown increasingly more difficult to do in today's competitive environment led by the expanding e-commerce. A prerequisite to achieve this is that mall management tries to accomplish mutual cooperation with their tenants in an effort to create synergy between the various components within the mall. This puts even more weight on the center management's relationship with the tenants. Therefore, this study aims to investigate which factors that is important in the relationship between mall management and tenants in a shopping center environment and also to ascertain tenant´s interdependence between each other. In order to fulfill this purpose a survey has been conducted. This has in turn been distributed to the shopping centers Mitticity and Galleria Duvan, both located in Karlstad. The results of the study indicate that participants value a vivid communication with the center management and that they have the opportunity to participate as well as influence the key decisions within the mall. However, the result also shows that respondents are divided when it comes to the center management's flexibility and the pursuit of a long-term tenancy. In the case of tenant´s interdependence, results indicate that the participants notice the value of anchor tenants and that they agree with that both their own store and neighboring shops benefit from the customers that each store attracts. However, the results show that the majority of respondents feel that it is negative if the neighboring store offers similar products as their own.
74

How does industrial symbiosis influence environmental performance?

Onita, John January 2006 (has links)
A collaborative approach to industry-environment issues is acknowledged as a key aspect of sustainable development. Sincerely, resource sharing among firms offers the potential to increase stability of operations, especially in supply-constrained areas, by ensuring that access to important inputs such as water, energy and raw materials are guaranteed. Industrial Symbiosis (IS), a sub-field of Industrial Ecology, is primarily concerned with the cyclical flow of resources through networks of industrial units as a means of cooperatively approaching environmentally sustainable industrial activity. In line with this principle, a critical assessment of the change in environmental performance brought about by industrial symbiosis (IS) was conducted in nineteen selected eco-industrial park case studies identified in all regions of the world with the exception of the African continent. Case study selection criteria were based on models of eco-industrial parks proposed by Chertow (2000). A description of the type of material exchanges that go on in each case study was carried out which revealed evidence of implemented synergies in respective case studies. A comparative assessment of cross-case patterns which is a semi-quantitative matrix used to quantify the degree of environmental performance showed that there was a clear evidence of improved environmental performance among respective case studies investigated where water, energy and material flows served as indicators. Results obtained from the study showed a common pattern of industrial presence in respective case studies reflecting the occurrence of heavy process industries such as oil refineries, cement industries, petrochemical industries, and steel industries. The principle of “anchor tenant” proposed by some experts in the field of industrial ecology was strongly supported by the obtained results. Symbiotic cooperation among participating firms in respective case studies were mainly on areas like cogeneration, re-use of materials, recycling and wastewater treatment and re-use.
75

Comparison Of 3d Facial Anchor Point Localization Methods

Yagcioglu, Mustafa 01 June 2008 (has links) (PDF)
Human identification systems are commonly used for security issues. Most of them are based on ID card. However, using an ID card for identification may not be safe enough since people may not have any protection against the theft. Another solution to the identification problem is to use iris or fingerprints. However, systems based on the iris or fingerprints need close interaction to identification machine. Identifying someone from his photograph overcomes all these problems which can be called as face recognition. Common face recognition systems are based on the 2D image recognition but success rates of these methods are strictly depending on the environment. Variations on brightness and pose, complex background are the main problems for 2D image recognition systems. At this point, three dimensional face recognition techniques gain importance. Although there are a lot of methods developed for 3D face recognition, many of them assume that face is not rotated and there is not any destructive (i.e. beard, moustache, hair, hat, and eyeglasses) on the face. However, identification needs to be done though these destructives. Basic step for the face recognition is the determination of the anchor points (i.e. nose tip, inner eye points). In this study, the goal is to implement previously proposed four face recognition methods based on anchor point detection / &ldquo / Multimodal Facial Feature Extraction for Automatic 3D Face Recognition&rdquo / , &ldquo / Automatic Feature Extraction for Multiview 3D Face Recognition&rdquo / , &ldquo / Multiple Nose Region Matching for 3D Face Recognition under Varying Facial Expression&rdquo / , &ldquo / 3D face detection using curvature analysis&rdquo / , to compare the success rates of them for rotated and destructed images and finally to propose improvements on these methods.
76

Strengthening of noncomposite steel girder bridges with post-installed shear connectors : fatigue behavior of the adhesive anchor

Patel, Hemal Vinod 21 November 2013 (has links)
This thesis describes part of the work associated with Project 0-6719 sponsored by the Texas Department of Transportation (TxDOT). The primary objective of the project is to examine the feasibility of strengthening older continuous multi-span steel girder bridges through the use of post-installed shear connectors. Bridges potentially eligible for retrofit have noncomposite floor systems, where the concrete slab is not attached to the steel girders with shear connectors. Many of these bridges were designed in the 1950's and 1960's for loads smaller than the standard design loads used today. A secondary objective of the project, and the main focus of this thesis, is to examine the design of post-installed shear connectors for fatigue. Of particular interest in this study is the adhesive anchor, given its convenient installation procedure but relatively poor fatigue performance in previous tests. The objectives of this thesis were to quantify the fatigue strength of the adhesive anchor, as well as quantify the shear force and slip demands on adhesive anchors in realistic bridge conditions. In regards to the first objective, twenty-six direct shear fatigue tests were performed on adhesive anchors. Each test was conducted on a single adhesive anchor in order to capture its individual cyclic load-slip behavior. Results indicate that adhesive anchors have considerably higher fatigue strength than conventional welded shear studs, making partial composite design feasible in the strengthening of older steel bridges. In regards to the second objective, analytical and computational studies were conducted on composite beams with adhesive anchors. Results show that the shear force and slip demands are typically smaller than the endurance limits determined from direct-shear testing. This suggests that fatigue failure of adhesive anchors under service loads may not be a primary concern. Based on the results, preliminary recommendations for the design of adhesive anchors for fatigue are provided. / text
77

Experimental modeling for in-plane and out-of-plane loading of scaled model drag embedment anchors

Kroncke, Mark William 03 September 2009 (has links)
The failed anchoring systems of mobile offshore drilling units from hurricanes occurring in 2004 and 2005 established a need to better understand the ultimate pullout capacity and trajectory of scaled model anchors under typical and out-of-plane loading conditions. The six degrees of freedom of small scale drag embedment anchors were studied in a laboratory testing environment with the intent that reasonable trends in anchor behavior will be found. Investigations within this experimental research program demonstrated the in-plane and out-of-plane loading behavior of conventional and prototype scaled model anchors embedded to predetermined depths in two different test beds of kaolinite clay with undrained shear strength profiles constant and increasing with depth. The anchors were loaded to failure in concentric, normal, concentric, shear, eccentric, normal, eccentric, shear, inclined, and drag embedment loading configurations. This series of pullout and drag embedment tests provided a suite of test results indicating behavioral trends of the varying holding capacities and anchor trajectories. Results were compared with similar research presented in the literature and an analytical model predicting out-of-plane loading behavior of similar anchors. It was concluded that increasing eccentricities from both concentric, normal and concentric, shear loading configurations resulted in decreasing bearing capacity factors, confirming the predicted trend from the analytical model for these loading configurations. Trajectories observed for the concentric, normal, concentric, shear, and eccentric, shear loading configurations showed that the anchors tracked straight out of the soil without deviation, but eccentric, normal loading found the anchor tending to track away from the initial loading location. For inclined loads, both anchors to track to whichever direction the anchor faced upon loading. Drag embedment trajectory was found to vary depending on the anchor, as the conventional anchor dove with an applied load and the prototype anchor rose towards the surface. / text
78

Basement  Membrane  Dynamics  During  Anchor  Cell  Invasion

Morrissey, Meghan Ann January 2015 (has links)
<p>Basement membranes are a dense, sheet-like form of extracellular matrix that underlie epithelia and endothelia, and surround muscle, fat and Schwann cells. Basement membranes separate tissues and protect them from mechanical stresses. Although traditionally thought of as a static support structure, a growing body of evidence suggests that dynamic basement membrane deposition and modification instruct cell behavior and morphogenetic processes. In this thesis, I discuss how changes to basement membrane affect anchor cell (AC) invasion during C. elegans uterine vulval attachment. During AC invasion, the uterine AC breaches two juxtaposed basement membranes to contact the underlying vulval epithelium. Using live-cell imaging, genetics, molecular biology and electron microscopy I identify three modifications to the BM that affect AC invasion. In Chapter 2, I describe a system for linking juxtaposed basement membranes to stably align or connect adjacent tissues. This adhesion system promotes rapid AC invasion and also regulates a more long-term connection between the uterine tissue and the hypodermal seam cell in the adult worm. Chapter 3 elucidates how the BM component SPARC promotes cell invasion. As SPARC overexpression is correlated with cancer metastasis, this aims to understand how SPARC overexpression promote invasion in a pathological situation. In Chapter 4, I discuss preliminary data showing that the AC actively secretes laminin into the basement membrane targeted for invasion. I outline how future studies could elucidate the mechanism by which AC-derived laminin might promote cell invasion. Finally, Chapter 5 discusses conclusions and future directions for these studies.</p> / Dissertation
79

Shear strengthening of reinforced concrete beams with carbon fiber reinforced polymer (CFRP) under fatigue and sustained loading applications

Satrom, Christopher Neil 29 September 2011 (has links)
Four specimens were tested to evaluate the shear performance of beams with carbon fiber reinforced polymer (CFRP) laminates and CFRP anchors under fatigue and sustained loading applications. The specimens consisted of 24-in. deep T-beams that were constructed and tested at Phil M. Ferguson Structural Engineering Laboratory at the University of Texas at Austin. The specimens were strengthened in shear with CFRP laminates anchored with CFRP anchors. One end of each specimen was strengthened using bonded CFRP laminates while the other end was strengthened using unbonded CFRP laminates. Two specimens were used for fatigue testing and two were used for sustained load testing. For each set of tests, one specimen was strengthened using CFRP laminates prior to cracking and one specimen was strengthened using CFRP laminates following the initial cracking of the specimen. The CFRP laminates showed no signs of deteriorations in strength during fatigue testing, with only small increases in strain occurring in the CFRP laminates during testing. After fatigue loading was completed, the specimens were monotonically loaded to failure. The failure loads were 5 to 15% lower than beams that were not subjected to fatigue loading. Sustained load tests were subjected to a constant midpoint load based on service load requirements for a period of 217 days. CFRP laminates performed well during sustained loading. CFRP strains increased slightly throughout testing, but no signs of deterioration were observed. For both types of tests, specimens strengthened using bonded CFRP laminates demonstrated an increased stiffness resulting in smaller crack widths and lower strains in the internal steel. These benefits were not as great in specimens strengthened after the initial cracking of the specimen. / text
80

Experimental Testing of CFRP Splays Bonded to Uniaxial Fabric

Rivers, Roger Troy January 2014 (has links)
The use of fiber reinforced polymers (FRP's) for structural repair or retrofit has increased significantly in the last decade, with adoption for civil infrastructure occurring only in the last 20 years. These products are most often used to increase the capacity of damaged or deteriorated structures. Much research has been performed in the arena of testing of various FRP's bonded to both concrete and masonry substrates, the majority of which focusing on three areas; flexural strengthening, in-plane shear strengthening, and mechanical anchoring. Anchorage is commonly the limiting factor in the application of FRP's, due to the inability of the edge of the polymer matrix to reliably extend beyond a point of zero-interfacial stress. Where interfacial stresses exist and the FRP is terminated localized disbondment often occurs, these localized failures then propagate across the entire bond of the structural system. Various mechanical termination details have been tested to mitigate the potential failure modes near the ends of the fabric. There, however, has been very limited research performed on the behavior of dowels which are installed parallel to the FRP fabric and splayed onto the FRP fabric matrix. In this research the mechanical properties of carbon fiber reinforced polymer (CFRP) dowels with a parallel orientation to uniaxial carbon fabric are experimentally tested to determine the tensile capacity of "dowel to splay" CFRP connections and to discover any dominant failure modes.

Page generated in 0.0227 seconds