DaKS - University of Kassel's research data repository

This is the code used to produce results for the publication "Multiplexer Optimizations for Virtex FPGAs" by N. Fiege, M. Hardieck and P. Zipf, presented at the 35th International Conference on Field-Programmable Logic and Applications (FPL) in Leiden, Netherlands during September, 2025.
The README.md file contains the VHDL code describing the multiplexers as well as all necessary information to reproduce the results presented in the paper. We are actively working on applying these optimizations to other FPGA architectures within the following repository: https://gitlab.uni-kassel.de/uk025743/mux_opt

Abstract:
Multiplexers (MUX) are essential elements in Field-Programmable Gate Arrays (FPGA), widely used in practical applications. Due to the LUT-based architecture of FPGAs, multiplexers that switch among many signals or operate on large word sizes incur significant resource costs, as these costs scale linearly with the data word size. Vivado’s automatic synthesis flow often produces sub-optimal MUX implementations, necessitating hand-crafted solutions to minimize resource overhead. Here, we present three MUX implementation schemes that reduce resource usage for various input signal counts. These optimizations enable enhanced resource efficiency in applications ranging from circuits generated by High-Level Synthesis (HLS) tools to optimized digital filters and artificial neural networks.

This study provides a detailed analysis of the crystalline structure of polyamide 5.10 (PA5.10) and determines the effects of hydrothermal aging on its moisture content, crystallinity, and texture. Using wide-angle X-ray scattering (WAXS), the investigation revealed insights into both the amorphous boundary layer and the semi-crystalline core, with a Python script based on Bragg’s law enabling precise identification of crystalline phase planes. Gaussian fitting of crystalline peaks further refined the structural understanding. The effects of experimental parameters on WAXS measurements were examined to identify additional factors influencing PA5.10. Hydrothermal aging led to notable changes, including increased moisture absorption, volume expansion, enhanced crystallinity, and shifts in molecular structure and crystalline morphology. WAXS showed that moisture-induced scattering reduced intensity, which was reversible upon re-drying. Despite an increase in crystallinity observed by DSC, WAXS did not capture a corresponding shift, likely due to the combined effects of residual moisture and annealing processes. Overall, this study enhances the understanding of PA5.10's crystalline behavior under hydrothermal exposure and provides a basis for future investigations into its aging processes and structural evolution. These findings contribute to a broader understanding of the long-term degradation mechanisms and stability of bio-based polyamides under hydrothermal and humid conditions. Moreover, the insights gained are relevant for predicting material performance in moisture-sensitive applications and can inform the development of stabilization strategies for hygroscopic polymers.

This dataset consists of the measured data from the conducted experiments, python scripts as well as the data analysis.
In case you use the data please cite the corresponding article. The corresponding publication is currently in publication process.

Polyamides are known for their chemical resistance and are commonly used as matrix materials in glass fiber-reinforced composites (GFC) for automotive applications such as fuel caps and housings. To assess the potential of natural fiber-reinforced composites (NFC) as alternatives, this study investigates the chemical resistance of a bio-based polyamide (PA5.10) reinforced with regenerated cellulose fibers (RCF). Composites containing 20 wt.% RCF were produced using twin-screw extrusion, and standardized type 1A test specimens were injection molded. These were exposed to various fluids (distilled water, salt water, soap water, acid rain, rubbing alcohol, engine oil, ethanol, sodium hydroxide solution, and 2-propanol) for up to 168 hours. Subsequent analyses included tensile testing, FTIR spectroscopy, MVR, moisture measurements, and SEM imaging. Results revealed significant hydrolytic degradation, indicated by FTIR and decreased viscosity. Degradation was especially pronounced in acidic and alkaline media. A strong link was observed between increased moisture uptake and reduced mechanical properties. Chemical exposure led to notable damage in RCF composites, attributed to the moisture absorption of RCF and fiber degradation, as confirmed by SEM images. Loss of fiber-matrix adhesion further contributed to substantial declines in tensile strength and Young’s modulus. These findings highlight limitations in chemical resistance for RCF-reinforced bio-based polyamides, especially under harsh environmental conditions.

This data set consists of the measured data from the conducted experiments as well as the data analysis.
In case you use the data please cite the corresponding article. The corresponding publication is currently in publication process.