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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.
11

Gold(I)-Catalyzed Synthesis of Polycyclic Frameworks Related to Terpenes: Selective Divergent Synthesis of Fused Carbocycles

Barabe, Francis January 2013 (has links)
Gold catalysis has become an important tool to achieve highly chemoselective p-acid activation. Exceptional reactivity and selectivity are often encountered under mild reaction conditions. These properties have made gold(I) complexes suitable catalysts for tremendous applications in the total synthesis of natural products. The first chapter will highlight a number of total syntheses using gold catalysis as a key step. The second chapter will cover our application of the gold(I)-catalyzed 6-endo-dig carbocyclization for the synthesis of bridgehead-substituted scaffolds and its use toward the synthesis of PPAP natural products. This research has opened our eyes to the utility of biphenylphosphine ligands, particularly JohnPhos, in gold(I)-catalysis. The reactivity and selectivity exhibited by gold(I) complexes is modulated by the nature of the ancillary ligand. Recent research rationalizes the impact of these ligands on the divergent reactivity observed between cationic and carbenoid intermediates. Our desire to favor the 6-endo-dig pathway has led us toward the discovery of another example of the diagonal reactivity that NHC carbene and biphenylphosphine ligands can bring to gold(I)-catalysis. Chapter three will explain the development of a selective gold-catalyzed synthesis of fused carbocycles . Our selective divergent synthesis of fused carbocycles, combined with the Diels–Alder reaction, has brought new synthetic opportunities. Chapter four will describe our approach toward the synthesis of various polycyclic diterpene-related frameworks. Starting with a unique linear precursor, we have developed a new “one-pot” process for the synthesis of three different polycyclic compounds related to the terpenoid family. The facile modulation of the linear precursor and the use of different dienophiles during the Diels–Alder reaction could enable the synthesis of diverse polycyclic analogues based on three principal frameworks. The gold(I)-catalyzed synthesis of fused carbocycles reached some limitations during our study. Regioselective control was found to be substantially more challenging, with terminal alkynes or alkynes bearing a sterically and electronically neutral methyl substituent. In chapter five, we will discuss how the complementarity of silver(I) catalysis to gold(I) catalysis enabled the selective divergent synthesis of three different fused carbocycles from a unique precursor. Moreover, copper(I) catalysis has given access to the 6-endo-dig pathway on terminal alkynes without the formation of a vinylidene intermediate.
12

Výroba přírub s využitím postupu PPAP a normy ISO 9001 / Production of flanges using the procedure PPAP , and ISO 9001

Prokeš, Tomáš January 2016 (has links)
In the first part of this thesis is described implementation of quality management system in a small company according to ISO 9001. Next part is about production process by method PPAP. In this section is solved primarily ISO 9001 standard, statistical control of production and certification company according to requirements of ISO 9001. Second part is focused on mass production of flange by using the company facilities Kovobrábění Sobotka. In the end of thesis are reflected weaknesses of production. In the conclusion is described technical and economic evaluation of implementation QMS and machining sample parts.
13

Integration of Advanced Product Quality Planning in Quality Preparation for an Original Equipment Manufacturer in the Automotive Industry : A Case Study at Volvo Group Trucks Operations Powertrain Production in Skövde

Gertsson, Hanna, Lindberg, Henrik January 2023 (has links)
This study examines the development of Volvo Group Trucks Operations Powertrain Production (Volvo GTO PTP) in Skövde, focusing on the implementation of processes for new products intended for both internal and external customers. Previously, the company solely supplied products within the Volvo Group, functioning as an Original Equipment Manufacturer (OEM). With the opportunity to adhere to the supplier-specific quality standard IATF 16949:2016, an extension of the ISO 9001:2015 quality standard. Volvo GTO PTP aims to enhance product and process development through the adoption of the Advanced Product Quality Planning (APQP) method. Unlike the existing project models, Develop Product and Aftermarket Product Portfolio (DVP) and Project Steering Model (PSM), used by Volvo GTO PTP, the APQP method validates product and process development together.   This study investigates the relationship between the current project models, DVP and PSM, and the APQP model, identifying areas within APQP that require further development. Interviews and thematic analysis were conducted to assess the current state of APQP, with an evaluation matrix employed for quantitative analysis. Findings reveal a knowledge gap within Volvo GTO PTP, wherein comprehension of APQP activities and their correlation with DVP and PSM is lacking. Critical activities for execution and management within the APQP model include measurement system analysis (MSA), checking aids, records of customer-specific requirements, part submission warrant, and Production Part Approval Process (PPAP). Furthermore, organizational culture-related deficiencies contribute to the difficulties in adopting a holistic project perspective due to siloed working practices.    The integration of APQP in the existing project models is recommended to Volvo GTO PTP in Skövde, as many APQP activities are already established or easily implementable. This integration facilitates the clear definition and demonstration of interplay between different project models, clarifying deliveries and the release of product and process development. To avoid reactive approaches to problem management, it is advisable to explicitly define responsibility for risk management and activities within the APQP model. The demand for APQP activities emphasizes their interconnectedness and creates a natural flow within the project model, contributing to an improved organizational culture and understanding of APQP. Ultimately, the APQP model establishes favorable conditions for reducing quality-related costs during the introduction of new products and product changes, ensuring appropriate preparedness in quality management. Compliance with IATF 16949:2016 also offers Volvo GTO PTP in Skövde the opportunity to obtain certification.

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