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The performance level of customer services (for example, short time for delivery of customer orders and economical service process) in manufacturing enterprises greatly depends on an effective manufacturing planning and control system (MPCS). The hierarchical planning approach of most MPCS may have resulted in critical situations, such as rigidity in the planning structure, complex control system...
The Rutherford Appleton Laboratory has built a small pixel detector for spectroscopic measurements of high energy X-rays using CdTe and CdZnTe. The detector has an array of 20×20 pixels on a 250μm pitch with each pixel bonded to a separate channel on an application specific integrated circuit (ASIC). Each channel in the ASIC contains a charge preamplifier, leakage current compensation circuit, shaping...
Nuclear Resonance Fluorescence (NRF) has the potential of addressing a wide variety of applications, which require isotopic and/or elemental information about a sample. We have investigated a variety of non-proliferation applications that may be addressed by NRF. From these applications, we have selected two, measuring uranium enrichment in UF6 cylinders and material verification in dismantlement,...
This paper analyzes the Intense Pulsed Active Detection (IPAD) approach for active detection of fissile material, highlights some of its merits, and compares it to the multiple-pulse-train LINAC approach. In both cases, bremsstrahlung photons are used to induce fissions. IPAD's single, 100-ns bremsstrahlung pulse offers the possibility to utilize prompt as well as delayed neutrons emitted during the...
Soft cosmic ray tomography has been shown to successfully discriminate materials with various density levels due to their ability to deeply penetrate matter, allowing sensitivity to atomic number, radiation length and density. Because the multiple muon scattering signal from high Z-materials is very strong, the technology is well suited to the detection of the illicit transportation of special and...
This main part of this thesis is concerning with the delamination phenomenon of quad flat no leads package (QFN) between epoxy molding compound (EMC) and exposure bottom paddle in IC package assembly factories. The characteristics show that the delamination phenomenon of QFN product occurred after Electro de-flash process (ED). ED process is making use of the redox reaction to produce hydrogen (H2)...
Indium doped lead telluride-based photodetectors have demonstrated extremely high performance in the terahertz range. These materials reveal a number of advantageous features: “internal” accumulation of the incident radiation, high spatial and temporal stability, high radiation hardness and others.
Further miniaturization of electronic systems is approaching new limits due to the failure mechanism of electromigration. Electromigration results in a transport of material in solder joints subjected to high electric current densities. This decreases the system reliability and, therefore, assessing and quantifying this failure mechanism becomes necessary.
Based on the requirements for miniaturization of a biocompatible package for medical implants, we derived a process flow for hermetic encapsulation of individual dies. In order to be cost-effective, wafer level based processing is used for this packaging flow. All processes are carried out using conventional clean room tools. Hermeticity of the individual dies or microsystems is ensured by using a...
Robustness and reliability for electronic boards are key issues, especially in the aeronautics industry. To study the reliability of the assembly, accelerated tests are performed on daisy chain components assembled on Printed Circuit Board (PCB). Times to failure of components need to be accurately detected to propose relevant fatigue and reliability models. To electrically monitor the daisy chains,...
A monochromatic millimeter wave system coupled with an infrared temperature sensor has been used to investigate pictorial artworks. The flexibility of the system makes it possible to rapidly reveal buried layer information such as a graphite handmade sketch covered by paintings.
Heavy metals accumulate in organisms as a result of direct uptake from the surroundings across the body wall, from respiration and from food. Uptake via food is most important in terrestrial organisms and it may also be important in the aquatic environment. Dietary uptake can include heavy metals adsorbed on particulates present on the surface of leaves etc, which have not been absorbed by the plant...
The connotation and basic principles of action-oriented teaching are introduced in his paper. And the process of taking action-oriented as teaching concept, implementing integrated teaching and developing students' key abilities by synthetically using various teaching methods contained in action-oriented teaching is described in detail, combined with vocational education of mechanical manufacturing...
This paper discussed the necessity, the possibility and the method of introducing GIS technology into LCA database study, analyzed the database structure and data elements of LCA database that included the data of the three pillars -ecology, economics, and social equity, a more comprehensive LCA database is innovated in this study.
Cracking along the intermetallic compound (IMC) interface in solder joints is the most important failure mechanism in electronics packages. In order to understand the failure mechanism well, a 2D solder/IMC interface model is used to examine the stress around the interface. Three solder materials, Sn37Pb, Sn3.5Ag and Sn3.0Ag0.5Cu, and various IMC thicknesses, which represent different growth stages...
For application of a lead-free composite solder in advanced electrical components, lead-free Sn3.5Ag0.5Cu composite solder was produced by mechanically mixing 0.5 wt.% nano-TiO2 particles with Sn3.5Ag0.5Cu solder. The corrosion behavior of the new Sn3.5Ag0.5Cu composite solder in 3.5 wt.% NaCl solution was investigated by using potentiodynamic polarization methods. The corrosion products formed during...
It is closely related between innovation ability of scientific and technical personnel in universities and personnel assignment system of scientific research in universities. The paper analyzes the disadvantages of personnel assignment system that restricts scientific and technical personnel innovation in China's universities, namely insufficiency of direction in personnel management system, insufficiency...
The IMC has become an important criterion when assessing the reliability of portable electronics. The quality of solder joints directly determines the drop-impact reliability of the product. As a structural member of the electronic product, IMCs are used to connect the solders and the associated printed circuit board by a proper joining technique such as the surface mount technology (SMT). Inter-metallic...
This paper analyzes knowledge-sharing barriers and incentives of university scientific research and innovation teams through a questionnaire survey. We find that knowledge-sharing barriers of university scientific research and innovation teams include psychological barriers, managing barriers and communicating barriers. Knowledge-sharing incentives of university scientific research and innovation...
Stationary energy storage technologies can improve the efficiency of transit systems. In this paper, three different demonstrations of energy storage technologies for transit systems were reviewed and discussed. The demonstrations reviewed were a sodium sulphide battery system in Long Island, a flywheel system for the London Underground, and a capacitor system for Madrid de Metro. Analysis was conducted...
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