Optical fiber-based open source low cost portable spectrometer system

This article explores the development of a small, compact fiber-based spectrometer system designed to overcome the limitations of standard spectrometers, such as the high cost and restricted accessibility. Operated by a Raspberry Pi, the fiber-based spectrometer system uses the increased computing power to provide versatile modes of operation and powerful data processing, while maintaining a small size. Specifically crafted for basic chemistry and biology lab setups, where fibers allow measurements in different conditions, and customization enables fluorescence, light scattering, and absorption measurements. The system is adaptable and versatile, offering ease of modification and adaptation for a broad range of applications.

Examining the Effect of Cu and Mn Dopants on the Structure of Zinc Blende ZnS Nanopowders

It is known that doping zinc sulfide (ZnS) nanoparticles with Mn or Cu ions significantly affects their luminescent properties. Herein, we investigated how dopant atoms are incorporated into the structure of ZnS using X-ray diffraction and multi-edge X-ray absorption spectroscopy. The observed broadening of the X-ray diffraction patterns indicates an average crystallite size of about 6 nm. By analyzing the Zn, Mn, and Cu K-edge extended X-ray absorption fine structure (EXAFS) spectra using the reverse Monte Carlo method, we were able to determine the relaxations of the local environments around the dopants. Our findings suggested that upon the substitution of Zn by Mn or Cu ions, there is a shortening of the Cu-S bonds by 0.08 Å, whereas the Mn-S bonds exhibited lengthening by 0.07 Å. These experimental results were further confirmed by first-principles density functional theory calculations, which explained the increase in the Mn-S bond lengths due to the high-spin state of Mn2+ ions.

Effect of Core-Shell Rubber Nanoparticles on the Mechanical Properties of Epoxy and Epoxy-Based CFRP

The aim of the research was to estimate the effect of core-shell rubber (CSR) nanoparticles on the tensile properties, fracture toughness, and glass transition temperature of the epoxy and epoxy-based carbon fiber reinforced polymer (CFRP). Three additives containing CSR nanoparticles were used for the research resulting in a filler fraction of 2-6 wt.% in the epoxy resin. It was experimentally confirmed that the effect of the CSR nanoparticles on the tensile properties of the epoxy resin was notable, leading to a reduction of 10-20% in the tensile strength and elastic modulus and an increase of 60-108% in the fracture toughness for the highest filler fraction. The interlaminar fracture toughness of CFRP was maximally improved by 53% for ACE MX 960 at CSR content 4 wt.%. The glass transition temperature of the epoxy was gradually improved by 10-20 °C with the increase of CSR nanoparticles for all of the additives. A combination of rigid and soft particles could simultaneously enhance both the tensile properties and the fracture toughness, which cannot be achieved by the single-phase particles independently.

Programmable material testing device for mechanoluminescence measurements

Mechanoluminescent materials transform mechanical energy into visible light. Phenomena could prove to be advantageous to various next-generation monitoring systems employed in the fields of security and healthcare if the intrinsic mechanisms are fully understood. Scientific efforts are mainly hindered by the lack of equipment capable of controlled mechanical deformation and simultaneous collection of light emitted by the sample. This article describes an easily constructible material testing device (508 €) with an interchangeable test fixture and an integrated load cell made from readily available mechanical components and 3D printed parts. A commercial low-cost alternative to spectroscopic apparatus (200 €) has recently become available alongside a highly capable 16-bit CMOS camera intended for low light conditions (520 €). A highly modular prototype system with an overall cost much lower than commercial alternatives that provide less functionality could enable a larger portion of scientific personnel to contribute to a novel field of research.

Portable low-cost open-source wireless spectrophotometer for fast and reliable measurements

We demonstrate a low-cost standalone portable spectrophotometer for fast and reliable measurement execution. The data acquired can be both displayed via a dedicated smartphone application or a computer interface, allowing users either to gather and view data on the move or set up a continuous experiment. All design and software files are open-source and are intended for the device to be easily replicable and further customizable to suit specific applications. The assembled device can measure absorption in the wavelength range from 450 nm to 750 nm with a resolution of 15 nm and is housed in a 90 × 85 × 58 mm casing. Validation of the device was carried out by assessing wavelength accuracy, dynamic range and the signal-to-noise ratio of the system, followed by testing in three different applications where limit of quantification, limit of detection and relative standard deviations were determined. The results indicated better performance than low-cost spectrophotometers, on average being comparable to moderate to high-cost spectrophotometers.