• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 29
  • 25
  • 12
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 85
  • 19
  • 16
  • 13
  • 11
  • 10
  • 9
  • 8
  • 8
  • 8
  • 7
  • 7
  • 7
  • 7
  • 7
  • 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.
81

Quantification of emissions in the ICT sector – a comparative analysis of the Product Life Cycle Assessment and Spend-based methods. : Optimal value chain accounting (Scope 3, category 1)

Rajesh Jha, Abhishek kumar January 2022 (has links)
Considering the rapid increase in the ICT (Information & Communication Technology) products in use, there is a risk of an increase in GHG emissions and electronic waste accumulation in the ICT sector. Therefore, it becomes important to account for the emissions in the ICT sector in order to take steps to mitigate them. There are several methods put forward under ETSI, ITU-T, GHG protocol, etc., which can be used to measure the emissions in the ICT sector. Two such methods are Product Life Cycle Assessment (PLCA) and Spend-based, which are used in this study to account for scope 3, category 1 emissions in the ICT sector. Scope 3, category 1 emissions are released during the raw material acquisition and part production phase of the ICT product’s life cycle and account for a major portion of the overall emissions. As the ICT sector is a very huge field of study in itself, two ICT products, namely smartphones and laptops, are considered in this study to calculate their overall scope 3, category 1 emissions. A list of influential components in smartphones and laptops is defined to be included in the Excel Management Life Cycle Assessment (EMLCA) tool to calculate the scope 3, category 1 emissions. A comprehensive comparison between PLCA and Spend-based methods is also studied during the process of calculating their emissions. These observations are then used to make critical analyses and compare the two methods under results and discussions based on various parameters described under them. Both the methods were found to be suitable for calculating the emissions, with some uncertainty, although the Spend-based method was a quicker approach to do so. The PLCA method, although more complex, was found to be more suitable for ICT product eco-design. Both methods required a different set of primary data and were sensitive to various components in smartphones and laptops. This study illustrates the parameters that affect PLCA and Spend-based methods and discusses the pros and cons of them depending on the situations they are used in.
82

Thermal Cycling Fatigue Investigation of Surface Mounted Components with Eutectic Tin-Lead Solder Joints

Bonner, J. K. "Kirk", de Silveira, Carl 10 1900 (has links)
International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / Eutectic (63% tin-37% lead) or near-eutectic (40% tin-60% lead) tin-lead solder is widely used for creating electrical interconnections between the printed wiring board (PWB) and the components mounted on the board surface. For components mounted directly on the PWB mounting pads, that is, surface mounted components, the tin-lead solder also constitutes the mechanical interconnection. Eutectic solder has a melting point of 183°C (361°F). It is important to realize that its homologous temperature, defined as the temperature in degrees Kelvin over its melting point temperature (T(m)), also in degrees Kelvin, is defined as T/T(m). At room temperature (25°C = 298K), eutectic solder's homologous temperature is 0.65. It is widely acknowledged that materials having a homologous temperature ≥ 0.5 are readily subject to creep, and the solder joints of printed wiring assemblies are routinely exposed to temperatures above room temperature. Hence, solder joints tend to be subject to both thermal fatigue and creep. This can lead to premature failures during service conditions. The geometry, that is, the lead configuration, of the joints can also affect failure. Various geometries are better suited to withstand failure than others. The purpose of this paper is to explore solder joint failures of dual in-line (DIP) integrated circuit components, leadless ceramic chip carriers (LCCCs), and gull wing and J-lead surface mount components mounted on PWBs.
83

Elektronická stavebnice v předmětu Praktické činnosti / Electronic kit in the subject Practical activities

ŠMRHA, Jiří January 2012 (has links)
In this thesis I focused on the evaluation of the historical development of electronic kits in the Czech school system, and the survey of the current state of use of electronic kits in the subject Praktické činnosti (Practical Activities) on the second level of primary schools. The thesis also presents a comparison of different types of electronic kits using complex eva-luation criteria. Another part deals with design and implementation of a custom electronic kit intended for teaching the subject Praktické činnosti (Practical Activities), including the implementation of appropriate didactic instruction.
84

Evidence for a dual origin of insect wings via cross-wiring of ancestral tergal and pleural gene regulatory networks

Deem, Kevin David 06 April 2022 (has links)
No description available.
85

Rekonstrukce elektrické části vytloukacího roštu / Reconstruction of discharging shakeout machine electric installation

Bednář, Vojtěch January 2016 (has links)
This Diploma work is concerned with the design of project documentation for discharging shakeout machine electric installation. This work continues in the Semestral project 2 in which the background of a new machine was made. Then, this work deals with the replacement of a switch room with required devices including the design of a new connecting cables and power streams. In the first part, the work deals with the control part of the device and the design of control and signal cables including the product documentation of the device. In the second part, the work deals with the proposal of building electro installation in which a new lighting and its use is described. The last part focuses on the coordination during the realization of a suggested device. In this part, all problems coming from the particular working procedures including a proposal of possible solutions are described. According to the project documentation and following realization, the documentation of final concept reflecting the real status of the device is described.

Page generated in 0.0416 seconds