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  • 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.
61

Estudo da influência da adição de borracha vulcanizada em concreto à temperatura ambiente e elevada temperatura /

Marques, Ana Carolina. January 2005 (has links)
Orientador: Jorge Luís Akasaki / Banca: Jefferson Sidney Camacho / Banca: Armando Lopes Moreno Júnior / Resumo: O presente trabalho tem como objetivo estudar algumas propriedades de concretos e argamassas, com substituição parcial do agregado miúdo por resíduos de borracha de pneus provenientes do processo de recauchutagem. Para todas as misturas foi utilizado o cimento CP V - ARI PLUS, areia e, para os concretos, brita basáltica. As substituições foram de 12% em volume do agregado miúdo por borracha para argamassa e 10% em volume para concreto. Em argamassa procurou-se verificar a influência do tratamento do resíduo de borracha com solução saturada de hidróxido de sódio. As propriedades estudadas foram: resistência à compressão, resistência à tração, absorção de água e índice de consistência. As propriedades analisadas em concreto à temperatura ambiente foram: resistência à compressão, absorção de água, resistência à tração, resistência à abrasão, módulo de elasticidade e resistência à flexão. Em concreto aquecido a 600ºC, avaliaram-se as propriedades de resistência à compressão e módulo de elasticidade. Os resultados obtidos em argamassas, após o tratamento do resíduo, mostram que este não influencia nas propriedades estudadas. Também é observado, após a substituição de parte do agregado pelo resíduo, queda na trabalhabilidade e nos resultados referentes à resistência mecânica. Os resultados de resistência à abrasão em concreto mostram-se interessantes para o uso da mistura em pavimentação. Após o aquecimento do concreto, observa-se redução na resistência à compressão e módulo de elasticidade para as misturas com e sem borracha. Também é observado que as relações de perda de resistência entre o concreto com e sem borracha são mantidas após o aquecimento. / Abstract: The aim of this work is to study some properties of mortars and concretes, whose fine aggregate was partially replaced by tire rubber from retreading process. It was used in all mixes CPV - ARI PLUS cement, river sand, and basaltic coarse aggregate. The replacement was made in volume of fine aggregate by tire rubber and it was 12% in mortars and 10% in concrete. The influence of the residue's treatment with a sodium hydroxide saturated solution was analyzed through tests in mortar. The studied properties were: compressive strength, splitting tensile strength, water absorption, and consistence index. The properties analyzed in concrete at room temperature were: compressive strength, splitting tensile strength, modulus of elasticity, and flexural tensile strength. The tests made at 600ºC heated concrete were compressive strength and modulus of elasticity. The results from mortars tests, after the rubber's treatment, show that it doesn't influence considerably the studied properties. It is also observed that after the replacement of part of the aggregate by tire rubber; there is a decrease in workability and mechanical tests results. The abrasion resistance tests results show that an interesting use to tire rubber concrete is in precast-concrete paving brick. It can be noted from the heated concrete results that compressive strength and modulus of elasticity decrease in mixes with and without tire rubber. It could be also seen that the relationship between concrete strength losses are kept after heating. / Mestre
62

Caracterização dos finos de areia de uma fundição e sua incorporação em argamassa de cimento /

Oliveira, Débora Ferreira de. January 2014 (has links)
Orientador: Maria Lúcia Pereira Antunes / Banca: Sandro Donnini Mancini / Banca: Antonio Carlos Vieira Coelho / Resumo: O trabalho está entre os dez países que possuem a maior produção mundial de fundidos, movimentando aproximadamente onze bilhões de dólares por ano para uma produção de mais de três milhões de toneladas/ano. Com esta alta produtividade, a indústria de fundição gera um grande volume de resíduos, dentre eles, destacam-se os finos de areia oriundos dos sistemas de areia captados durante os processos de moldagem e desmoldagem. Este resíduo é gerado em considerável quantidade e por isso seu descarte é um dos motivos da diminuição do espaço disponível em aterros, acarretando um alto custo para as indústrias de fundição. Assim, faz-se necessário a obtenção de técnicas para reaproveitamento deste resíduo, sendo uma das alternativas aq sua utilização em matriz de cimento Portland. Esta opção além de reduzir custos com descartes em aterros, também contribui com a redução do consumo e dos custos de insumos na área da construção civil. Com o objetivo de estudar este reaproveitamento, o presente trabalho foi realizado com finos de areia coletados em dois pontos do sistema de areia de uma fundição de aço. Estes resíduos foram caracterizados por fluorescência de raios X (FRX), por espectroscopia de energia dispersiva (EDS), difração de raios X (DRX) e análises da morfologia e do tamanho das partículas. Sua incorporação em argamassa de cimento foi realizada com corpos de prova em substituição à parte do agregado miúdo e corpos de prova em substituição à parte do cimento. Estes corpos de prova com diferentes percentuais de resíduos foram avaliados através de ensaios de resistência à compreensão, absorção de água, índice de vazios e massas específicas. Os resultados da caracterização do resíduo demonstraram uma predominância de óxidos de ferro, cromo, alumínio e silício, caracterizando-o como proveniente de uma areia de cromita, com propriedades hidrofilicas e de granulometria fina... / Abstract: Brazil is among the ten countries with highest wordwide production of casting products, driving about eleven billion dollars a year, producing more than three million tons/year. With this high productivity, the foundry industry generates large amounts of waste, which stands out the fine sand originating from the sand systems, during the process of molding and demolding. This waste is begotten in considerable quantity, so their disposal is one of the reasons for the decrease in available space in landfills, resulting in a high cost for foundry industry. Thus, it is necessary to find techniques to reuse this waste, as an alternative to this, it use in Portland cement matrix. This option could reduce costs with disposal at landfills and also contributes to the reduction of consumption and input costs in the construction area. In order to study this reuse, this work was performed with fine sand had gathered at two points of sand system on a steel foundry. These waste were characterized by X-ray fluorescence (XRF), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and analysis of morphology and particle size. Their incorporation into coment mortar was performed with specimens to replace part of the aggregate and speciments to replace part of the cement. These specimens with different percentages of waste were evaluated by compressive strength test, water absorption, voids and densities. The results of waste's characterization showed a predominance of iron oxides, chromium, aluminum and silicon, characterizing them as a them as a chromite sand, with hydrophilic properties and fine particle size. These characteristics influenced the other analyses, resulting in a more brittle and porous mortar, the compressive strength reduced proportionally with the increase percentages of waste. However the results were satisfactory, because these ar according to the standard NBR-13281 - mortar for laying and coatings. Concluding that the... / Mestre
63

Omni-Channel Retail and the New Age Consumer: An Empirical Analysis of Direct-to-Consumer Channel Interaction in the Retail Industry

Dorman, Alec J 01 January 2013 (has links)
It is indisputable that the internet has become a necessary component of contemporary multi-channel retail, as more consumers are choosing to purchase goods online each year. As online spending continues to grow, many have called into question the future of brick-and-mortar retail. This thesis seeks to empirically prove that brick-and-mortar retail remains not only relevant, but indispensable in direct-to-consumer business models. The basis of this conjecture is the idea of channel synergism, in which online and brick-and-mortar operations are complementary. This theory is predicated on the emergence of the omni-channel retail, which is characterized by the integration of the various direct-to-consumer (D2C) channels to support cross-channel consumer interaction. To empirically test this hypothesis, key operating metrics were examined over the five year period from 2007 to 2011. By examining profitability trends and several D2C channel relationships, empirical support is developed to substantiate the claim that brick-and-mortar operations are not being driven into obsolescence by the growing prevalence of e-commerce transactions.
64

Combining the Benefits of Traditional Commerce and E-Commerce with M-Commerce benefits in the Retail Industry

Corbitso, Kenneth, Ash, Thomas, Pisone, Neil January 2011 (has links)
The convergence of traditional and electronic commerce practices is being driven by the need for businesses to keep up with the ever increasing competition of online retailing. This thesis aims to examine and analyze the possible benefits that may arise via the use and development of rapidly evolving mobile technology, through analyzing the benefits of each of the forms of commerce during outlined stages of retail process, in order to evaluate to what extend the benefits can be combined. The benefits of each form of commerce were studied by observing existing theories and validated as perceived benefits through consumer surveys and management interviews.The theoretical part of this thesis is based on academic literature in the subject of Traditional commerce, Electronic commerce and Mobile commerce. The empirical studies were conducted as both qualitative and quantitative research, with a consumer survey conducted with 350 students, as well as two interviews with managers of retail stores in Västerås, Sweden.Results of the analysis shows that Mobile commerce has a role to play in better combining the benefits of traditional and electronic commerce and results in a combined figure implementing the findings into a working model, which we have dubbed ‘the four I’s of commerce’. The results are aimed at aiding retail managers in determining whether or not to implement a revised business model including the aspect of mobile commerce.
65

Slag cement mortar add bentonite in the study of anti-corrosion

Wang, Chong-Wei 08 February 2011 (has links)
In this study, we use the swelling characteristics of bentonite to discussion about the performance of bentonite mortar anti-seepage and the performance of resistance to sulfate. And add the AE water-reducing to improve its workability. To compare with different rate of bentonite added at different ratio of AE water-reducing in the condition of Standard Test for Flow Table. We planning in different water-cement ratio (0.445,0.485,0.550) to test for its fresh properties and hardened properties, and discussion the effect by AE water-reducing on the marine engineering. According to this study, adding bentonite will make the flow value dropped, and affecting the workability. Because of the positive ion exchange properties between bentonite and water will make it a high volume exchange rate, it means that absorption is high, so when the mixing time, the bentonite will form clumps, in this study, we add the AE water-reducing to improve. After we add AE water-reducing, the absorption, compressive strength are increase, but we still had to pay attention to the ratio between bentonite and AE water-reducing, the strength of structure perhaps decrease if added too much bentonite. This study can get the best positive effect when added ratio of 0.25% of bentonite to replaced cement.
66

A Study on the Model of Building New Brand Image: By the Case of SARAI

Huang, Yu-Ting 16 May 2012 (has links)
This study aimed to explore the model of building new brand image by integrating case study method, internal manager interview, and external dealer interview. The main objectives of this study are: (1) Probing into the progress and the development stages of SARAI, (2) Exploring the manner of SARAI on using traditional marketing, internet marketing, and community marketing to build brand image, (3) Exploring how SARAI to use ¡¥clicks and mortar¡¦ to build brand image, (4) Making suggestion about the brand image building model of SARAI. This study finds that the advantage of cost and quality is the major drive of the progress of SARAI. Secondly, the way that SARAI using owner as brand endorser, makes benefits of higher customer trust, more brand topics, lower endorsement risk, and higher cost/value effect. Hence, the endorsement model of SARAI becomes the main source and core concept of the brand image building tools about traditional marketing, internet marketing, and community marketing. Thirdly, propaganda artifact, lecture, dealer/store clerk education are the main tools which could make direct influence to the brand image SARAI. Resulting from the sort time period of on-line date, internet and community marketing tools could not make great contribution to brand image yet. Finally, as a result of the strategic and operational consideration and trade-off, building brand image is the main facet of the ¡¥clicks and mortar¡¦ of SARAI. Suggestions are discussed in accordance with findings.
67

Static and dynamic response of sandstone masonry units bound with fibre reinforced mortars

Islam, Md Toihidul Unknown Date
No description available.
68

A study of how the Brick and Mortar business can utilize Location-based Marketing in Sweden. : Technologies, Strategies, Privacy & Integrity and Receptiveness from a consumer and expert perspective.

Lagström, Philip, Stenlund, Gustaf January 2014 (has links)
Title: A study of how the Brick and Mortar business can utilize Location-based Marketing in Sweden. - Technologies, Strategies, Privacy & Integrity and Receptiveness from a consumer and expert perspective. Date: 2014-05-20 Level: Bachelor Thesis in Marketing Authors: Philip Lagström and Gustaf Stenlund. Supervisor: Klaus Solberg Søilen. Purpose: The purpose of this research is to create an understanding of what location-based marketing is and how brick and mortar businesses in Sweden can use this type of marketing, and how it affects sales and the customer experience. The objective is also to find out how consumers percept location-based marketing and possible privacy and integrity concerns. Theoretical framework: The theoretical framework begins with theory regarding Smartphone usage in Sweden and privacy & integrity concerns. The theory also discusses the brick and mortar business. Further, it discusses what kinds of techniques and methods that are used by location-based marketing today is, and how push and pull strategies can be used within location-based marketing. Method: The research is based on a combination of a qualitative and quantitative study. This was made to get the experts point of view and also the consumers’ perspective. The qualitative part consisted of three interviews with experts in the field of location-based marketing, mobile applications, Smartphone marketing and digital marketing. The quantitative part consisted of a survey with 357 participants Empirical framework: The empirical study consists of interviews and a survey. It begins with the interviews with the three experts; this part involves thoughts regarding location-based marketing within brick and mort, best method of LBM, consumer receptiveness, negative/positive aspects, privacy and integrity and future prospects for location-based marketing. This followed by the results from the quantitative survey with our 357 respondents; the survey gives a consumer point of view on important factors such as Smartphone use, consumer interest regarding LBM, receptiveness, privacy and integrity concerns and loyalty. Conclusion: The conclusion made in this dissertation is that location-based marketing is a great part of the digital marketing mix, and could potentially work well for Swedish brick and mortar businesses. It has potential to create increased value for consumers, which in turn can develop into a loyal customer base. The respondents of our survey are not concerned about their privacy and integrity. However, it could be a devastating blow for retailers if dealt with incorrectly.
69

Omni-Channel Retail and the New Age Consumer: An Empirical Analysis of Direct-to-Consumer Channel Interaction in the Retail Industry

Dorman, Alec J 01 January 2013 (has links)
It is indisputable that the internet has become a necessary component of contemporary multi-channel retail, as more consumers are choosing to purchase goods online each year. As online spending continues to grow, many have called into question the future of brick-and-mortar retail. This thesis seeks to empirically prove that brick-and-mortar retail remains not only relevant, but indispensable in direct-to-consumer business models. The basis of this conjecture is the idea of channel synergism, in which online and brick-and-mortar operations are complementary. This theory is predicated on the emergence of the omni-channel retail, which is characterized by the integration of the various direct-to-consumer (D2C) channels to support cross-channel consumer interaction. To empirically test this hypothesis, key operating metrics were examined over the five year period from 2007 to 2011. By examining profitability trends and several D2C channel relationships, empirical support is developed to substantiate the claim that brick-and-mortar operations are not being driven into obsolescence by the growing prevalence of e-commerce transactions.
70

Static and dynamic response of sandstone masonry units bound with fibre reinforced mortars

Islam, Md Toihidul 11 1900 (has links)
This research project describes the impact resistance of masonry units bound with fibre-reinforced Type S mortars and hydraulic lime mortar. The dynamic impact factor and stress rate sensitivity were evaluated for the flexural strength of the mortar and the bond strength, and further, the pattern of failure was noted for each mix and loading rate. Results show that the impact resistance of the masonry units increased in the presence of fibres. However, the stress rate sensitivity of the bond strength decreased with an increase in fibre content. Also, whereas the mode of failure in those masonry units bound with plain Type S mortars was through fracture at the mortar-block interface, the addition of fibres transferred the failure plane to within the masonry block. For hydraulic lime mortar, fibre reinforcement retained the sacrificial nature of mortar and also increased the flexural toughness factor of the joint even under dynamic loading. / Structural Engineering

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