Polyethylene terephthalate is one of the most important engineering thermal plastics used for fibers, films and bottles. Despite its wide applications and vast global market, PET has shortcomings, which limits it usage in many areas. PET has a glass transition temperature (Tg) of 80 DEGREE Celsius, this temperature is too low for certain applications. Increase in glass transition temperature, high temperature mechanical properties, and dimensional stability is of great importance to further expand the applications of PET. Significant research efforts have been made toward this goal, using a variety of approaches. In this work, we attempt to improve the properties of PET melt spun filament. Three strategies has been investigated (i) copolymerization of more rigid comonomer, 4, 4' bibenzoate unit into the PET structure, (ii) UV crosslinking of functionalized PET fiber, and (iii) Reinforcing PET matrix with carbon nanofibers.

Proton Exchange Membrane (PEM) fuel cell stack requires gaskets and seals in each cell to keep the hydrogen and air/oxygen within their respective regions. The stability of the gaskets is critical to the operating life as well as the electrochemical performance of the fuel cell. Chemical degradation of five elastomeric gasket materials in a simulated and an aggressive accelerated fuel cell solution at PEM operating temperature for up to 63 weeks was investigated in this work. The five materials are Copolymeric Resin (CR), Liquid Silicone Rubber (LSR), Fluorosilicone Rubber (FSR), Ethylene Propylene Diene Monomer Rubber (EPDM), and Fluoroelastomer Copolymer (FKM). In order to assess the durability of the materials, observation of chemical degradation level, dynamic mechanical analysis, and micro-indentation test were adopted in this study. This experimental result showed that the influence of the chemical reaction could affect the material surface condition. Also, the chemical reaction could affect material¡¦s mechanical properties had been changed over the soaking time. By considering the level of chemical degradation and mechanical properties, the experimental results showed that EPDM is recommended as the best choice of sealing material for using in a PEMFC.

This paper has mentioned the detailed process in which MP3 has been porting so as to being executed on the plate of ARM9 and working device of AACI¡BMMU¡BI-Cache¡BD-Cache¡BDMA¡BI-TCM¡BD-TCM on the developing board of Versatile VPB926EJS; the device has reduced clock Rate of ARM926EJ CPU. On the basis of lowest Clock Rate, the software of MP3 player could be executed smoothly with the little hardware resource.

Asphalt pavements experience damage due to traffic loading under various environmental conditions. Damage can be caused by viscopl microcracks, fracture due to fatigue cracking, or fracture due to thermal cracking. Asphalt pavements have the capability to remedi s damage depending on binder surface and rheological properties, filler surface properties, and length of rest periods. Asphalt mastic (asphalt and fine aggregates) properties play an important role in controlling damage and healing. This dissertation development of a comprehensive methodology to characterize damage and healing in asphalt mastics and mixtures. The methodology reli ctive imaging techniques (X-ray CT), principles of continuum damage mechanics, and principles of micromechanics. The X-ray CT yield meter that quantifies the percentage of cracks and air voids in a specimen. The continuum damage model parameters are derived from p between applied stress and pseudo strain. The micromechanics model relates the damaged mastic modulus to a reference undamaged mo ationship is a function of internal structure properties (void size, film thickness, and percentage of voids), binder modulus, aggr and bond energy between binder and aggregates. The internal structure parameters are all obtained using X-ray CT and correlated. The developed methodology was used to characterize damage in asphalt mastic and mixture specimens tested using the Dynamic Mechanic A) and dynamic creep test. The damage parameter measured using X-ray CT correlated very well with the predictions of the continuum ics models. All damage parameters were able to reflect the accumulation of damage under cyclic loading and were also able to captur of moisture conditioning on damage. Although this dissertation focused on fatigue cracking at room temperatures, the methodology d used to assess damage due to different mechanisms such as permanent deformation and low temperature cracking.

This dissertation describes the use of measured aerosol size distributions and size-resolved hygroscopic growth to examine the physical and chemical properties of several particle classes. The primary objective of this work was to investigate the optical and cloud forming properties of a range of ambient aerosol types measured in a number of different locations. The tool used for most of these analyses is a differential mobility analyzer / tandem differential mobility analyzer (DMA / TDMA) system developed in our research group. To collect the data described in two of the chapters of this dissertation, an aircraft-based version of the DMA / TDMA was deployed to Japan and California. The data described in two other chapters were conveniently collected during a period when the aerosol of interest came to us. The unique aspect of this analysis is the use of these data to isolate the size distributions of distinct aerosol types in order to quantify their optical and cloud forming properties. I used collected data during the Asian Aerosol Characterization Experiment (ACE-Asia) to examine the composition and homogeneity of a complex aerosol generated in the deserts and urban regions of China and other Asian countries. An aircraft-based TDMA was used for the first time during this campaign to examine the size-resolved hygroscopic properties of the aerosol. The Asian Dust Above Monterey (ADAM-2003) study was designed both to evaluate the degree to which models can predict the long-range transport of Asian dust, and to examine the physical and optical properties of that aged dust upon reaching the California coast. Aerosol size distributions and hygroscopic growth were measured in College Station, Texas to investigate the cloud nucleating and optical properties of a biomass burning aerosol generated from fires on the Yucatan Peninsula. Measured aerosol size distributions and size-resolved hygroscopicity and volatility were used to infer critical supersaturation distributions of the distinct particle types that were observed during this period. The predicted cloud condensation nuclei concentrations were used in a cloud model to determine the impact of the different aerosol types on the expected cloud droplet concentration. RH-dependent aerosol extinction coefficients were also calculated.

<p>This Master's Thesis describes the design of a new system where a digital signal processor has been added to an existing imaging system consisting of field programmable gate arrays. The new system will offer a higher degree of flexibility by considerably shortening the design time and make it possible to implement more complex algorithms than the existing ones. </p><p>The choice of system architecture and a test implementation are discussed. The test implementation consists of a program for the digital signal processor and VHDL code for one of the field programmable gate arrays. </p><p>The code for the digital signal processor was designed for testing on an evaluation board from Texas Instruments. The evaluation board is connected to a computer, which runs a Windows program to visualize the result. </p><p>The choice of algorithm has not been made yet. In the test implementation a skewing algorithm is used as an example. Two implementations of the skewing algorithm has been optimized, one fix point version and one floating point version.</p>

Κύριος σκοπός της εργασίας είναι η υλοποίηση ενός υπολογιστικού συστήματος με Scratch pad μνήμη και η διαχείριση της μνήμης μέσω ενσωματωμένου λογισμικού. Αρχικά παρουσιάζονται τα πλεονεκτήματα και τα μειονεκτήματα ενός συστήματος που χρησιμοποιεί μνήμη Scratch pad σε σύγκριση με ένα αντίστοιχο σύστημα με cache. Μετά σχεδιάζουμε το σύστημα μας χρησιμοποιώντας την γλώσσα περιγραφής υλικού VHDL και λαμβάνουμε πειραματικές μετρήσεις οι οποίες προκύπτουν από την μέτρηση των κύκλων εκτέλεσης ενός αντιπροσωπευτικού προγράμματος. Η προτεινόμενη αρχιτεκτονική με Scratch pad και η τεχνική προγραμματισμού της αποφέρουν μια βελτίωση της απόδοσης κατά 36% σε σχέση με την αντίστοιχη αρχιτεκτονική με cache. Αυτό οφείλεται στις σημαντικά λιγότερες αστοχίες που παρουσιάζει η Scratch pad όταν προγραμματιστεί κατάλληλα καθώς ο DMA ελεγκτής έχει τη δυνατότητα να μεταφέρει τα δεδομένα παράλληλα με την εκτέλεση του προγράμματος. / The main purpose of this master thesis is the implementation of a computer system using scratch pad memory including memory management via embedded software. Initially we present the pros and cons of a system using scratch pad memory, in comparison to a system using cache memory. We then design our system using the hardware description language VHDL and we compare the performance with an equivalent architecture using cache memory. This is done by counting the clock cycles needed in order to run a sample program. The proposed scratch pad architecture and the programming technique used produced a 36% better performance in comparison to an equivalent cache memory architecture. This is due to the less misses that a scratch pad memory presents, when programmed efficiently.

The rapidly increasing capabilities of digital electronics have increased the demand of Software Defined Radio (SDR), which were not possible in the special purpose hardware. These enhanced capabilities come at the cost of time due to complex operations involved in multi-antenna wireless communications, one of those operations is complex matrix inversion. This thesis presents the verification and FPGA implementation of a SIMD processor, which was developed at Computer Engineering division of Linköping university, Sweden. This SIMD processor was designed specifically for performing complex matrix inversion in an efficient way, but it can also be reused for other operations. The processor is fully verified using all the possible combinations of instructions. An optimized firmware for this processor is implemented for efficiently inverting 4×4 matrices. Due to large number of subtractions involved in direct analytical approach, it losses stability for 4×4 matrices. Instead of this, a blockwise subdivision is used, in which 4×4 matrix is subdivided into four 2×2 matrices. Based on these 2×2 matrices, the inverse of 4×4 matrix is computed using the direct analytical approach and some other computations. Finally, the SIMD processor is integrated with Senior processor (a controlprocessor) and synthesized on Xilinx, Virtex-4 FPGA. After this, the performance of the proposed architecture is evaluated. A firmware is implemented for the Senior which uploads and downloads data/program into the SIMD unit using both I/O and DMA. / Den snabbt ökande prestandan hos digital elektronik har ökat behovet av Software Defined Radio (SDR), vilket inte var möjligt med tidigare hårdvara. Denna ökade förmåga kommer till priset av tidsåtgång, till följd av komplexa procedureri samband med trådlös kommunikation med flera antenner, en av dessa procedurer är komplex matrisinvertering. Denna avhandling presenterar verifiering och FPGA implementering hos en SIMD processor, vilken har blivit utvecklad vid institutionen för datorteknik, Linköpings universitet, Sverige. Denna SIMD processor blev specifikt designad för att genomföra komplex matrisinvertering på ett effektivt sätt, men kan också användas för andra tillämpningar. Processorn har testats och verifierats för alla möjliga kombinationer av instruktioner. En optimerad firmware för denna processor är implementerad för att effektivt invertera 4×4 matriser. På grund av att ett stort antal subtraktioner är inblandade i ett direkt analytiskt angreppssätt, så förlorar den stabilitet för 4×4 matriser. Istället används en stegvis indelning i underavdelningar, där 4×4 matrisen delasin i fyra 2×2 matriser. Baserat på dessa 2×2 matriser beräknas inversen av 4×4 matrisen med hjälp av ett direkt analytiskt angreppssätt samt andra beräkningar. Slutligen, SIMD processorn är integrerad i en huvudprocessor och körs påXilinx, Virtex-4 FPGA. Efter detta utvärderas prestandan hos den föreslagna arkitekturen. Firmware implementeras hos huvudprocessorn som laddar upp och ned data/program till SIMD enheten genom I/O samt DMA.

A DMA Controller can offload a processor tremendously. A memory copy operation can be initiated by the processor and while the processor executes others tasks the memory copy can be fulfilled by the DMA Controller. An implementation of a DMA Controller for use in LEON3 SoC:s has been made during this master thesis. Problems that occurred while designing a controller of this type concerned AMBA buses, data transfers, alignment and interrupt handling. The DMA Controller supports AMBA and is attached to an AHB master and APB slave. The DMA Controller supports burst transfers to maximize data bandwidth. The source and destination address can be arbitrarily aligned. It supports multiple channels and it has interrupt generation on transfer completion along with interrupt masking. The implemented functionality works as intended.

SRAM-based Field Programmable Gate Arrays (FPGAs) must be programmed with configuration data every time they are powered on. In addition to initially programming an FPGA, there are many other applications that require access to FPGA configuration memory such as partial reconfiguration, fault injection, and memory scrubbing. This thesis describes a system that provides high-speed, programmable configuration management for Xilinx FPGAs through external interfaces. This system is an improvement upon the JTAG Configuration Manager (JCM) previously created at BYU. The JCM consists of a custom I/O board paired with a MicroZed development board which includes a Xilinx ZYNQ SoC. This platform is used to implement a flexible configuration management system that can communicate with Xilinx FPGAs at high speeds using the JTAG and SelectMAP interfaces.The improved system described in this thesis increases the maximum data transfer rate of the JCM's JTAG and SelectMAP interfaces and dramatically decreases the processor utilization of user programs running on the JCM. This is accomplished by incorporating a Direct Memory Access (DMA) engine and interrupts into the system. In addition to faster data rates, these changes and the decrease in processor utilization also allow the JCM to manage up to eight JTAG chains simultaneously with the use of a special I/O card.