Structure Tuning and Electrical Properties of Mixed PVDF and Nylon Nanofibers

The paper specifies the electrostatic spinning process of specific polymeric materials, such as polyvinylidene fluoride (PVDF), polyamide-6 (PA6, Nylon-6) and their combination PVDF/PA6. By combining nanofibers from two different materials during the spinning process, new structures with different mechanical, chemical, and physical properties can be created. The materials and their combinations were subjected to several measurements: scanning electron microscopy (SEM) to capture topography; contact angle of the liquid wettability on the sample surface; Raman spectroscopy; X-ray photoelectron spectroscopy (XPS); and Fourier-transform infrared spectroscopy ({FT-IR}) to describe properties and their changes at the chemical level. Crystallization events were determined by differential scanning calorimetry (DSC). Furthermore, the contact angle of the wettability of the liquid on the surface was measured for the materials, and the permittivity was measured to observe the dielectric properties. The advantage of the addition of co-polymers was to control the properties of PVDF samples and understand the reasons for the changed functionality. The innovation point of this work is the complex analysis of PVDF modification caused by mixing with nylon PA6. Here we empathize that the application of nylon during the spin influences the properties and structure (polarization, crystallization) of PVDF

RT LEVEL POWER CONSUMPTION ESTIMATION TOOL ABSTRACT

This paper deals with RT level power consumption estimation during test application. The goal of this paper is to describe design and implementation of custom power consumption estimation tool that works in collaboration with Mentor Graphic DfT tools. The proposed tool can be used in an early design stage for quick classification of various test sets according to power consumption without need of full synthesis and slow physical level simulation of the design. The tool is implemented as a library that makes it ideal for usage in various power consumption optimization techniques. 1

ABSTRACT GA BASED TEST SCHEDULING UNDER POWER CONSTRAINTS

This paper deals with test scheduling under power constraints. An approach based on genetic algorithm operating on Test Application Conflict Graph is presented. The main goal of the method is to minimize test application time with considering structural resource allocation conflicts and to ensure that test application schedule does not exceed chip power limits. The proposed method was implemented using C++, experimental results with ITC’02 SOC benchmark suite are presented in the paper together with the perspectives for the future research.

Comprehensive characterization of PVDF nanofibers at macro- and nanolevel

This study is focused on the characterization and investigation of polyvinylidene fluoride (PVDF) nanofibers from the point of view of macro- and nanometer level. The fibers were produced using electrostatic spinning process in air. Two types of fibers were produced since the collector speed (300 rpm and 2000 rpm) differed as the only one processing parameter. Differences in fiber’s properties were studied by scanning electron microscopy (SEM) with cross-sections observation utilizing focused ion beam (FIB). The phase composition was determined by Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy. The crystallinity was determined by differential scanning calorimetry (DSC), and chemical analysis of fiber’s surfaces and bonding states were studied using X-ray photoelectron spectroscopy (XPS). Other methods, such as atomic force microscopy (AFM) and piezoelectric force microscopy (PFM), were employed to describe morphology and piezoelectric response of single fiber, respectively. Moreover, the wetting behavior (hydrophobicity or hydrophilicity) was also studied. It was found that collector speed significantly affects fibers alignment and wettability (directionally ordered fibers produced at 2000 rpm almost super-hydrophobic in comparison with disordered fibers spun at 300 rpm with hydrophilic behavior) as properties at macrolevel. However, it was confirmed that these differences at the macrolevel are closely connected and originate from nanolevel attributes. The study of single individual fibers revealed some protrusions on the fiber’s surface, and fibers spun at 300 rpm had a core-shell design, while fibers spun at 2000 rpm were hollow

GNU Radio

GNU Radio is a free & open-source software development toolkit that provides signal processing blocks to implement software radios. It can be used with readily-available, low-cost external RF hardware to create software-defined radios, or without hardware in a simulation-like environment. It is widely used in hobbyist, academic, and commercial environments to support both wireless communications research and real-world radio systems