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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.
41

Vzduchotěsnost obvodových konstrukcí a kritických detailů / Air tightness of building structures and critical details

Vávra, Petr January 2015 (has links)
In thesis is dealt with problematic of how the value of air permeability may be affected by properties for water vapour diffusion with regard to OSB material There were chosen two main brands of OSB at Czech trade market Two specimens of OSB with different thickness were chosen for each brand. As a first the specimens were tested for air tightness to work out a value of air permeability for each specimen. Afterwords, the testing was conducted for gaining properties of water vapour diffusion on each specimen. As a final assessment was analysed the impact of properties of water vapour diffusion on the air tightness for each specimen. The general meaning of gaining higher air tightness with higher water vapour resistance was proved . It was shown that with raising thickness is usually gotten higher value of water vapour diffusion resistance. However it could not mean getting high air tightness. The crucial parameter is the quality of the material for gaining higher resistance against water vapour diffusion as well as for higher airtightness.
42

Größenanalyse an nicht separierten Holzpartikeln mit regionenbildenden Algorithmen am Beispiel von OSB-Strands

Plinke, Burkhard 02 October 2012 (has links)
Bei strukturorientierten, aus relativ großen Holzpartikeln aufgebauten Holzwerkstoffen wie z.B. OSB (oriented strand board) addieren sich die gerichteten Festigkeiten der einzelnen Lagen je nach Orientierung der Partikel und der Verteilung ihrer Größenparameter. Wünschenswert wäre eine Messung der Partikelgeometrie und Orientierung möglichst im Prozess, z.B. am Formstrang vor der Presse direkt durch den „Blick auf das Vlies“. Bisher sind regelmäßige on-line-Messungen der Spangeometrie aber nicht möglich, und Einzelspanmessungen werden nicht vorgenommen, weil sie zu aufwändig wären. Um die Partikelkonturen zunächst hinreichend für die Vermessung zu restaurieren und dann zu vermessen, muss ein mehrstufiges Verfahren angewendet werden, das eine Szene mit Strands und mehr oder weniger deutlichen Kanten zunächst als „Grauwertgebirge“ auffasst. Zur Segmentierung reicht ein Watershed-Algorithmus nicht aus. Auch ein zweistufiger Kantendetektor nach Canny liefert allein noch kein ausreichendes Ergebnis, weil sich keine geschlossenen Objektkonturen ergeben. Hinreichend dagegen ist ein komplexes Verfahren auf der Grundlage der Höhenschichtzerlegung und nachfolgenden Synthese: Nach einer Transformation der Grauwerte des Bildes in eine reduzierte, gleichverteilte Anzahl von Höhenschichten werden zwischen diesen die lokalen morphologischen Gradienten berechnet und herangezogen für die Rekonstruktion der ursprünglichen Spankonturen. Diese werden aus den Höhenschichten aufaddiert, wobei allerdings nur Teilflächen innerhalb eines für die gesuchten Spangrößen plausiblen Größenintervalls einbezogen werden, um Störungen zu unterdrücken. Das Ergebnis der Rekonstruktion wird zusätzlich verknüpft mit den bereits durch einen Canny-Operator im Originalbild detektierten deutlichen Kanten und morphologisch bereinigt. Diese erweiterte Höhenschichtanalyse ergibt ausreichend segmentierte Bilder, in denen die Objektgrenzen weitgehend den Spankonturen entsprechen. Bei der nachfolgenden Vermessung der Objekte werden Standard-Algorithmen eingesetzt, wobei sich die Approximation von Spankonturen durch momentengleiche Ellipsen als sinnvoll erwies. Verbliebene Fehldetektionen können bei der Vermessung unterdrückt werden durch Formfaktoren und zusätzliche Größenintervalle. Zur Darstellung und Charakterisierung der Größenverteilungen für die Länge und die Breite wurden die nach der Objektfläche gewichtete, linear skalierte Verteilungsdichte (q2-Verteilung), die Verteilungssumme und verschiedene Quantile verwendet. Zur Umsetzung und Demonstration des Zusammenwirkens der verschiedenen Algorithmen wurde auf der Basis von MATLAB das Demonstrationsprogramm „SizeBulk“ entwickelt, das Bildfolgen verarbeiten kann und mit dem die verschiedenen Varianten der Bildaufbereitung und Parametrierung durchgespielt werden können. Das Ergebnis des Detektionsverfahrens enthält allerdings nur die vollständigen Konturen der ganz oben liegenden Objekte; Objekte unterhalb der Außenlage sind teilweise verdeckt und können daher nur unvollständig vermessen werden. Zum Test wurden daher synthetische Bilder mit vereinzelten und überlagerten Objekten bekannter Größenverteilung erzeugt und dem Detektions- und Messverfahren unterworfen. Dabei zeigte sich, dass die Größenstatistiken durch den Überlagerungseffekt und auch die Spanorientierung zwar beeinflusst werden, dass aber zumindest die Modalwerte der wichtigsten Größenparameter Länge und Breite meist erkennbar bleiben. Als Versuchsmaterial dienten außer den synthetischen Bildern verschiedene Sortimente von OSB-Strands aus Industrie- und Laborproduktion. Sie wurden sowohl manuell vereinzelt als auch zu einem Vlies arrangiert vermessen. Auch bei realen Strands zeigten sich gleiche Einflüsse der Überlagerung auf die Größenverteilungen wie in der Simulation. Es gilt aber auch hier, dass die Charakteristika verschiedener Spankontingente bei gleichen Aufnahmebedingungen und Auswerteparametern gut messbar sind bzw. dass Änderungen in der gemessenen Größenverteilung eindeutig den geometrischen Eigenschaften der Späne zugeordnet werden können. Die Eignung der Verarbeitungsfolge zur Charakterisierung von Spangrößenverteilungen bestätigte sich auch an Bildern, die ausschließlich am Vlies auf einem Formstrang aufgenommen wurden. Zusätzlich wurde nachgewiesen, dass mit der erweiterten Höhenschichtanalyse auch Bilder von Spanplattenoberflächen ausgewertet werden könnten und daraus auf die Größenverteilung der eingesetzten Deckschichtspäne geschlossen werden kann. Das vorgestellte Verfahren ist daher eine gute und neuartige Möglichkeit, prozessnah an Teilflächen von OSB-Vliesen anhand von Grauwertbildern die Größenverteilungen der Strands zu charakterisieren und eignet sich grundsätzlich für den industriellen Einsatz. Geeignete Verfahren waren zumindest für Holzpartikel bisher nicht bekannt. Diese Möglichkeit, Trends in der Spangrößenverteilung automatisch zu erkennen, eröffnet daher neue Perspektiven für die Prozessüberwachung. / The strength of wood-based materials made of several layers of big and oriented particles like OSB (oriented strand board) is a superposition of the strengths of the layers according to the orientation of the particles and depending from their size distribution. It would be desirable to measure particle geometry and orientation close to the production process, e.g. with a “view onto the mat”. Currently, continuous on-line measurements of the particle geometry are not possible, while measurements of separated particles would be too costly and time-consuming. Before measuring particle shapes they have to be reconstructed in a multi-stage procedure which considers an image scene with strands as “gray value mountains”. Segmentation using a watershed algorithm is not sufficient. Also a two-step edge detector according to Canny does not yield closed object shapes. A multi-step procedure based on threshold decomposition and recombination however is successful: The gray values in the image are transformed into a reduced and uniformly distributed set of threshold levels. The local morphological gradients between these levels are used to re-build the original particle shapes by adding the threshold levels. Only shapes with a plausible size corresponding to real particle shapes are included in order to suppress noise. The result of the reconstruction from threshold levels is then matched with the result of the strong edges in the original image, which had been detected using a Canny operator, and is finally cleaned with morphological operators. This extended threshold analysis produces sufficiently segmented images with object shapes corresponding extensively to the particle shapes. Standard algorithms are used to measure geometric features of the objects. An approximation of particle shapes with ellipses of equal moments of inertia is useful. Remaining incorrectly detected objects are removed by form factors and size intervals. Size distributions for the parameters length and width are presented and characterized as density distribution histograms, weighted by the object area and linearly scaled (q2 distribution), as well as the cumulated distribution and different quantiles. A demonstration software “SizeBulk” based on MATLAB has been developed to demonstrate the computation and the interaction of algorithms. Image sequences can be processed and different variations of image preprocessing and parametrization can be tested. However, the detection procedure yields complete shapes only for those particles in the top layer. Objects in lower layers are partially hidden and cannot be measured completely. Artificial images with separated and with overlaid objects with a known size distribution were generated to study this effect. It was shown that size distributions are influenced by this covering effect and also by the strand orientation, but that at least the modes of the most important size parameters length and width remain in evidence. Artificial images and several samples with OSB strands from industrial and laboratory production were used for testing. They were measured as single strands as well as arrangements similar to an OSB mat. For real strands, the same covering effects to the size distributions revealed as in the simulation. Under stable image acquisition conditions and using similar processing parameters the characteristics of these samples can well be measured, and changes in the size distributions are definitely due to the geometric properties of the strands. The suitability of the processing procedure for the characterization of strand size distributions could also be confirmed for images acquired from OSB mats in a production line. Moreover, it could be shown that the extended threshold analysis is also suitable to evaluate images of particle board surfaces and to draw conclusions about the size distribution of the top layer particles. Therefore, the method presented here is a novel possibility to measure size distributions of OSB strands through the evaluation of partial gray value images of the mat surface. In principle, this method is suitable to be transferred to an industrial application. So far, methods that address the problem of detecting trends of the strand size distribution were not known, and this work shows new perspectives for process monitoring.
43

Técnicas de otimização não-linear aplicada a algoritmos DSM

NEVES, Darlene Maciel 09 November 2007 (has links)
Submitted by Edisangela Bastos (edisangela@ufpa.br) on 2013-01-08T19:18:39Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_TecnicasOtimizacaoNaolinear.pdf: 1651076 bytes, checksum: fa57b2105cf7dc60b02f0754371ecee5 (MD5) / Approved for entry into archive by Ana Rosa Silva(arosa@ufpa.br) on 2013-01-17T14:43:15Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_TecnicasOtimizacaoNaolinear.pdf: 1651076 bytes, checksum: fa57b2105cf7dc60b02f0754371ecee5 (MD5) / Made available in DSpace on 2013-01-17T14:43:15Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_TecnicasOtimizacaoNaolinear.pdf: 1651076 bytes, checksum: fa57b2105cf7dc60b02f0754371ecee5 (MD5) Previous issue date: 2007 / Esta dissertação apresenta os algoritmos considerados estado-da-arte para gerenciamento dinâmico de espectro (DSM). As técnicas de otimização utilizadas nos algoritmos DSM são abordadas e brevemente discutidas para melhor entendimento, descrição e comparação dos algoritmos. A análise comparativa entre os algoritmos foi realizada considerando o ganho em taxa (kbps) obtido em simulações. Para tanto, foi realizado em laboratório um conjunto de medições de função de transferência direta e de acoplamento, posteriormente utilizadas nas simulações dos algoritmos IWF, ISB e SCALE. Os resultados obtidos nas simulações através do uso das funções de transferência medidas mostraram melhor desempenho quando comparados aos demais resultados ao considerar funções de transferência obtidas a partir do padrão 1% pior caso, resultado este reflexo da aproximação 1% em que os pares apresentam maiores níveis de crosstalk em todas as frequências da função de transferência. Dentre os algoritmos comparados, o ISB e SCALE obtiveram desempenho semelhante em canais padronizados, ficando o IWF com o desempenho próximo ao SSM. No entanto, nas simulações em cenários com canais medidos, os três algoritmos tiveram ganhos muito próximo devido ao baixo nível de crosstalk. / This M.Sc. thesis presents state-of-art algorithms for dynamic spectrum management (DSM). The strategy and description of each DSM algorithm are presented and briefly discussed as well as a comparative analysis between them for better understanding. This analysis was conducted considering the rate gain (kbps) obtained from computer simulations and the results are presented by tables and rate region curves. Additionally, it was conducted in laboratory a set of direct and coupling transfer function measurements. Later on, those measurements were used during DSM algorithms simulations; this dissertation focused in the IWF, ISB and SCALE algorithms. The results obtained from the transfer function measurements showed better performance compared to the results with transfer function 1% worst-case model. The later considers 1% of pairs present the biggest crosstalk level in all transfer function frequencies. In the case where standardized channels were employed, ISB and SCALE obtained similar performances whereas IWF had a performance quite similar to SSM. On the other hand, these three algorithms had similar gain in simulations evolving the measured channels because the low crosstalk level.
44

Seismic Design Of Cold Formed Steel Structures In Residential Applications

Uygar, Celaletdin 01 May 2006 (has links) (PDF)
iv ABSTRACT SEISMIC DESIGN OF COLD FORMED STEEL STRUCTURES IN RESIDENTIAL APPLICATIONS Uygar, Celaletdin M.Sc., Department of Civil Engineering Supervisor: Prof. Dr. &Ccedil / etin Yilmaz May 2005, 82 pages In this study, lateral load bearing capacities of cold formed steel framed wall panels are investigated. For this purpose lateral load bearing alternatives are analyzed numerically by computer models and results are compared with already done experimental studies and approved codes. In residential cold formed steel construction, walls are generally covered with cladding material like oriented strand board (OSB) or plywood on the exterior wall surface and these sheathed light gauge steel walls behave as shear walls with significant capacity. Oriented strand board is used in analytical models since OSB claddings are most commonly used in residential applications. The strength of shear walls depends on different parameters like screw spacing, strength of sheathing, size of fasteners used and aspect ratio. SAP2000 software is used for structural analysis of walls and joint force outputs are collected by Microsoft Excel. The yield strength of shear walls at which first screw connection reaches its shear capacity is calculated and load carrying capacity per meter length is found. The nonlinear analysis is also done by modeling the screw connections between OSB and frame as non-linear link and the nominal shear capacities of walls are calculated for different screw spacing combinations. The results are consistent with the values in shear wall design Guide and International Building Code 2003. The other lateral load bearing method is flat strap X-bracing on wall surfaces. Various parameters like wall frame section thickness, flat strap area, aspect ratio and bracing number are investigated and results are evaluated. The shear walls in which X-bracing and OSB sheathing used together are also analyzed and the results are compared with separate analyses.
45

Produção de painéis de partículas orientadas (OSB) a partir da madeira de um híbrido  de Pinus elliottii var. elliottii var. Pinus caribaea var. hondurensis / Production of oriented strand board (OSB) from a hybrid of Pinus elliottii var. elliottii x Pinus caribaea var. hondurensis

Surdi, Paula Gabriella 29 June 2012 (has links)
,O estudo sobre a qualidade da madeira de híbridos do gênero Pinus no Brasil é recente. Por outro lado, alguns dados disponíveis indicam que o material apresenta rápido crescimento e pode ser considerado promissor sob o ponto de vista silvicultural. O presente trabalho teve como objetivo principal avaliar o potencial de utilização da madeira do híbrido Pinus elliottii var. elliottii x Pinus caribaea var. hondurensis para a produção de painéis de partículas orientadas (Oriented Strand Board OSB). Para a realização do estudo foram utilizadas 10 toras (2,5 m de comprimento), sendo 05 delas provenientes de árvores de Pinus elliottii var. elliottii x Pinus caribaea var. hondurensis (PECH) e as outras 05 de árvores de Pinus taeda L. (PT). O delineamento experimental adotado na fase de manufatura dos painéis OSB constituiu-se de 08 tratamentos, arranjados em esquema fatorial, por meio dos quais foram analisados os efeitos de 02 ciclos de prensagem e 04 proporções de mistura de partículas de madeira de PECH e de PT. A partir dos painéis produzidos foram confeccionados corpos-de-prova para a realização de ensaios físicos (teor de umidade, densidade aparente, absorção de água e inchamento em espessura) e mecânicos (flexão estática e ligação interna), conduzidos conforme as normas ASTM D 1037 (2006) e DIN 52362 (1982). Mediante a análise dos resultados dos ensaios concluiu-se que: O aumento da proporção de partículas da madeira de PECH na manufatura experimental do OSB resultou em tendência de redução dos valores da massa específica e da maioria das propriedades mecânicas (MOR paralelo e MOE paralelo e perpendicular) dos painéis. A estabilidade dimensional foi influenciada negativamente com a alteração do ciclo de prensagem e a utilização de PECH em diferentes proporções, resultando em tendência de aumento dos valores de absorção de água e inchamento em espessura. Apesar das tendências observadas, os painéis OSB manufaturados com as partículas de madeira de PECH nas proporções 50% e 75% de mistura com as partículas de madeira de PT (tratamentos T4 e T3, ciclo de prensagem convencional), foram os que apresentaram o maior potencial de uso da madeira do híbrido, uma vez que atenderam aos requisitos mínimos indicados pela norma CSA (1993) para todas as propriedades mecânicas avaliadas. / The study about the quality of the wood of Pinus hybrids in Brazil is still recent. On the other hand, some data indicate that the material can be considered promising from the point of view silvicultural. This study aimed to evaluate the potential use of wood hybrid Pinus elliottii var. elliottii x Pinus caribaea var. hondurensis for the production of oriented strand boards (OSB). To conduct the study, 10 logs (2.5 m long) were used, from 05 trees of Pinus elliottii var. elliottii x Pinus caribaea var. hondurensis (PECH) and 05 trees of Pinus taeda L. (PT). The experiment consisted of eight treatments arranged in a factorial way, where the effects of 02 pressing cycles and 04 mixing ratios of wood particles of PECH and PT were analyzed. From the panels produced, samples were obtained to conduct physical tests (moisture content, bulk density, water absorption and thickness swelling) and mechanical (modulus of rupture, modulus of elasticity and internal bonding), tests according to ASTM D 1037 (2006) and DIN 52362 (1982) standards. Through the analysis of test results it was possible to conclude: Increasing the proportion of particles of PECH wood in the OSB manufacture experimental result in reduced trend in the values of density and most of the mechanical properties (MOR parallel and MOE parallel and perpendicular) of the panels. The dimensional stability was negatively affected by changing the pressing cycle and use of PECH in different proportions, resulting in increase trend of the values of water absorption and thickness swelling. Despite the trends, the OSB manufactured with particles of PECH wood in the proportions 50% and 75% mixed with particles of PT (treatments T4 and T3, conventional cycle), were the ones with the greatest potential for the use of hybrid wood, as they meet the minimum requirements specified by the standard CSA (1993) for all mechanical properties.
46

Návrh dřevostavby rodinného domu

Vařejka, Jindřich January 2015 (has links)
This thesis describes the design of wooden buildings house, whose layout corresponds to the size requirements of the four/five person family. The main objective is the development of technical documentation for realization wooden building system frame construction. The work is divided into text and section drawings. In the text part, we focus on the structural system of wooden frame. Further to the proposal of the building envelope system diffusion open structure. For each construction envelope is made of heat-technical assessment. The work is completely processed and architectural layout wooden buildings. The last part is focused on determining the gross price of the house. Drawing section contains both drawings needed for building permits and manufacturing documentation for implementation of wooden buildings house.
47

Produção de painéis de partículas orientadas (OSB) a partir da madeira de um híbrido  de Pinus elliottii var. elliottii var. Pinus caribaea var. hondurensis / Production of oriented strand board (OSB) from a hybrid of Pinus elliottii var. elliottii x Pinus caribaea var. hondurensis

Paula Gabriella Surdi 29 June 2012 (has links)
,O estudo sobre a qualidade da madeira de híbridos do gênero Pinus no Brasil é recente. Por outro lado, alguns dados disponíveis indicam que o material apresenta rápido crescimento e pode ser considerado promissor sob o ponto de vista silvicultural. O presente trabalho teve como objetivo principal avaliar o potencial de utilização da madeira do híbrido Pinus elliottii var. elliottii x Pinus caribaea var. hondurensis para a produção de painéis de partículas orientadas (Oriented Strand Board OSB). Para a realização do estudo foram utilizadas 10 toras (2,5 m de comprimento), sendo 05 delas provenientes de árvores de Pinus elliottii var. elliottii x Pinus caribaea var. hondurensis (PECH) e as outras 05 de árvores de Pinus taeda L. (PT). O delineamento experimental adotado na fase de manufatura dos painéis OSB constituiu-se de 08 tratamentos, arranjados em esquema fatorial, por meio dos quais foram analisados os efeitos de 02 ciclos de prensagem e 04 proporções de mistura de partículas de madeira de PECH e de PT. A partir dos painéis produzidos foram confeccionados corpos-de-prova para a realização de ensaios físicos (teor de umidade, densidade aparente, absorção de água e inchamento em espessura) e mecânicos (flexão estática e ligação interna), conduzidos conforme as normas ASTM D 1037 (2006) e DIN 52362 (1982). Mediante a análise dos resultados dos ensaios concluiu-se que: O aumento da proporção de partículas da madeira de PECH na manufatura experimental do OSB resultou em tendência de redução dos valores da massa específica e da maioria das propriedades mecânicas (MOR paralelo e MOE paralelo e perpendicular) dos painéis. A estabilidade dimensional foi influenciada negativamente com a alteração do ciclo de prensagem e a utilização de PECH em diferentes proporções, resultando em tendência de aumento dos valores de absorção de água e inchamento em espessura. Apesar das tendências observadas, os painéis OSB manufaturados com as partículas de madeira de PECH nas proporções 50% e 75% de mistura com as partículas de madeira de PT (tratamentos T4 e T3, ciclo de prensagem convencional), foram os que apresentaram o maior potencial de uso da madeira do híbrido, uma vez que atenderam aos requisitos mínimos indicados pela norma CSA (1993) para todas as propriedades mecânicas avaliadas. / The study about the quality of the wood of Pinus hybrids in Brazil is still recent. On the other hand, some data indicate that the material can be considered promising from the point of view silvicultural. This study aimed to evaluate the potential use of wood hybrid Pinus elliottii var. elliottii x Pinus caribaea var. hondurensis for the production of oriented strand boards (OSB). To conduct the study, 10 logs (2.5 m long) were used, from 05 trees of Pinus elliottii var. elliottii x Pinus caribaea var. hondurensis (PECH) and 05 trees of Pinus taeda L. (PT). The experiment consisted of eight treatments arranged in a factorial way, where the effects of 02 pressing cycles and 04 mixing ratios of wood particles of PECH and PT were analyzed. From the panels produced, samples were obtained to conduct physical tests (moisture content, bulk density, water absorption and thickness swelling) and mechanical (modulus of rupture, modulus of elasticity and internal bonding), tests according to ASTM D 1037 (2006) and DIN 52362 (1982) standards. Through the analysis of test results it was possible to conclude: Increasing the proportion of particles of PECH wood in the OSB manufacture experimental result in reduced trend in the values of density and most of the mechanical properties (MOR parallel and MOE parallel and perpendicular) of the panels. The dimensional stability was negatively affected by changing the pressing cycle and use of PECH in different proportions, resulting in increase trend of the values of water absorption and thickness swelling. Despite the trends, the OSB manufactured with particles of PECH wood in the proportions 50% and 75% mixed with particles of PT (treatments T4 and T3, conventional cycle), were the ones with the greatest potential for the use of hybrid wood, as they meet the minimum requirements specified by the standard CSA (1993) for all mechanical properties.
48

Využití modifikovaných částic ve výrobě OSB desek

Panáček, Radan January 2017 (has links)
Object of this thesis is to find out the influence of modified particles by plasma on properties of OSB board bonded by pMDI resin. Particles were made from veneer, because it is easier to modify by plasma (DCSBD). Produced particles were tested for chosen physical and mechanical properties. Results show degradation of properties of modified boards
49

Bici Decoraciones SAC

Cortez Salas, María Teresa Ysabel, Llano Canahuate, Julio Elmer, Garamendi Tomas, Wendy Yahaira, Grabau, César Rody 11 July 2020 (has links)
El presente proyecto del curso de Desarrollo de Negocios 2 de la Universidad Peruana de Ciencias Aplicadas, consiste en la creación de un soporte de madera para bicicletas que serán elaboradas con tableros OSB que nos asegura una alta resistencia en los soportes. Cabe recalcar, que nos vamos a dirigir a Lima Metropolitana en los distritos de mayor población en el uso de bicicletas y que además cuentan con acceso de ciclovías, tales como Surco, La Molina, San Isidro, San Borja y Miraflores, asimismo nos dirigiremos a los sectores socioeconómicos A y B, con un rango de edad de los 18 hasta los 45 años. El proyecto es viable, puesto que según la entrevista a profundidad que se realizó, se identificó un gran porcentaje de personas que usan la bicicleta como medio de transporte; parte de ello, la investigación también indica que los usuarios tienen dificultades para guardar sus bicicletas ya que no cuentan con el espacio adecuado en sus hogares. Por un lado, para la puesta en marcha del proyecto se necesitará una inversión inicial de S/. 51,884 soles, que será financiado al 100% por los accionistas sin necesidad de ser financiado por entidades bancarias. A su vez, tenemos en cuenta que los meses Diciembre, Enero, Marzo y Julio tendremos ventas elevadas que demostrada que el negocio es rentable. Por otro lado, el área de marketing hará uso de la publicidad digital, para ello se empleará las herramientas web como Facebook, Google Adwords, Landing Page y Community Manager, que nos permita una mejor difusión del producto. La distribución será coordinada directamente con el cliente a través de las redes sociales; también es importante indicar que se contará con distribuidores externos tales como Maestro y Sodimac. / The present Project of the Business Development course 2 of the Peruvian University of Applied Sciences, consists in the creation of a wooden support for bicycles that will be made with OSB boards that ensures high resistance in the supports. It should be noted that we are going to head to Metropolitan Lima in the districts with the largest population in the use of bicycles and that also have access to bicycle paths, such as Surco, La Molina, San Isidro, San Borja and Miraflores, we will also go to socioeconomic sectors A and B, with an age range of 18 to 45 years. The project is viable, since according to the in-depth interview that was carried out, a large percentage of people who use the bicycle as a means of transportation was identified; Part of it, the research also indicates that users have difficulty storing their bikes as they do not have adequate space in their homes. On the one hand, for the start-up of the project an initial investment of S /. 51,884 soles, which will be financed 100% by shareholders without the need to be financed by banks. At the same time, we take into account that the months of December, January, March and July will have high sales, which has proven that the business is profitable. On the other hand, the marketing area will make use of digital advertising, for this we will use web tools such as Facebook, Google Adwords, Landing Page and Community Manager, which allows us to better disseminate the product. The distribution will be coordinated directly with the client through social networks; It is also important to indicate that there will be external distributors such as Maestro and Sodimac. / Trabajo de investigación
50

Etude sur la biosynthèse de Naphtoquinones végétales et bactériennes

Dansette, Patrick M 12 October 1972 (has links) (PDF)
Les quinones sont des composés largement répandus dans la nature, aussi bien dans le règne végétal, qu'animal ou microbien. Ces molécules sont biosynthétisées à partir d'un petit nombre d'intermédiaires simples. Le noyau des naphtoquinones, en particulier, peut être synthétisé à partir de quatre précurseurs principaux l'acétate, la toluhydroquinone, le p-hydroxybenzoate et le shikimate. L'objet du présent travail est l'étude de la biosynthèse des naphtoquinones végétales ou bactériennes dérivant de l'acide shikimique (acide trihydroxy-3,4,5 cyclohexène-1 carboxylique), et la recherche des intermédiaires de cette voie de biosynthèse. Etant donné, à l'origine, l'absence quasi-totale de résultats expérimentaux dans ce domaine et le développement important qu'il a acquis en même temps que nous commencions notre travail, celui-ci a été constamment lié dans son développement aux données les plus récentes parues dans la littérature. Quelques études antérieures avaient montré que l'acide shikimique devait être le précurseur commun des acides aminés aromatiques et de plusieurs facteurs de croissance aromatiques (acide dihydroxy-2,3 benzoique, dihydroxy-3,4 benzoique, p-aminobenzoique et p-hydroxybenzoique) ainsi que de la ménaquinone de Escherichia coli (16,17). Lorsque nous commençons ce travail, on sait seulement que l'acide shikimique est incorporé in toto dans les ménaquinones bactériennes, de telle sorte que son carboxyle devient un des carbonyles de la quinone. Trois questions se posent alors: - Sur lequel des carbones 2 ou 6 adjacents au carboxyle, le cycle naphtoquinonique se ferme-t-il ? - Quelle est la molécule qui fournit les trois carbones nécessaires à la fermeture du cycle quinonique de la naphtoquinone, et quel est le mécanisme de cette fermeture ? - Le cycle naphtoquinonique ainsi formé est-il incorporé de façon symétrique ou non dans les ménaquinones, c'est-à-dire le carboxyle de l'acide shikimique est-il incorporé indifféremment dans les deux carbonyles quinoniques, ou sélectivement dans l'un des deux ? Pour résoudre la première question, LEISTNER et ZENK d'une part et M. LEDUC dans notre laboratoire d'autre part, ont utilisé l'acide shikimique [14 C-1,6]. Cette méthode nécessite une dégradation laborieuse des quinones formées. Nous avons, quant à nous, synthétisé un acide shikîmique [3H-3] marqué au tritium en une position spécifique, ce qui permet une dégradation simple et univoque. Une réponse partielle à la deuxième question a été donnée par CAMPBELL. Il montrait, en 1969, que le glutamate est capable d'apporter ses carbones 2, 3 et 4 pour la fermeture du cycle naphtoquinonique, mais il ne disposait pas alors des résultats de notre laboratoire lui permettant d'induire correctement le mécanisme de cette biosynthèse. Nous avons pu postuler la formation d'un intermédiaire, I'acide ortho-succinoylbenzoique OBS, dont nous avons pu prouver l'existence par synthèse et incorporation dans les quinones étudiées . L'existence de cet intermédiaire et la possibilité que nous avons eue de réaliser sur l'OSB différents marquages spécifiques nous ont permis de répondre à la troisième question, à savoir, l'incorporation orientée ou non de l'OSB dans les quinones. En même temps, différentes équipes montraient que d'autres quinones existant dans les végétaux telles que la lawsone, la juglone et différentes anthraquinones dérivaient aussi de l'acide shikimique; il nous a semblé intéressant d'appliquer nos techniques à l'étude très voisine de la biosynthèse de ces quinones. Pour la clarté de l'exposé, nous présentons dans le premier chapître les méthodes de synthèse des précurseurs radioactifs, dans le deuxième, les méthodes d'isolement et de dégradation des quinones. Les trois chapîtres suivants rapportent l'incorporation dans les ménaquinones, les naphtoquinones végétales et les anthraquinones végétales. Dans le sixième chapître, nous discutons nos résultats et proposons un schéma général de biosynthèse des quinones dérivant de l'acide shikimique. La partie expérimentale de ce travail est rassemblée après l'exposé théorique.

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