Children Hunger 2/13/1985 News Release Selct Committee on Hunger U.S. House of Representatives H2-507 School Lunch for Millions of Poor Children Threatened

Children Hunger 2/13/1985 News Release Selct Committee on Hunger U.S. House of Representatives H2-507 School Lunch for Millions of Poor Children Threatene

Blood equivalent phantom vs whole human blood, a comparative study

Preclinical research of biomedical optoelectronic devices is often performed with the use of blood phantoms — a simplified physical model of blood. The aim of this study is the comparison and distinction between blood phantoms as well as whole human blood measurements. We show how the use of such phantoms may influence the incorrect interpretation of measured signal. On the other hand, we highlight how the use of blood phantoms enables to investigate the phenomena that otherwise are almost impossible to be noticed

Comparability of Raman Spectroscopic Configurations: A Large Scale Cross-Laboratory Study

This is the final version. Available on open access from the American Chemical Society via the DOI in this recordThe variable configuration of Raman spectroscopic platforms is one of the major obstacles in establishing Raman spectroscopy as a valuable physicochemical method within real-world scenarios such as clinical diagnostics. For such real world applications like diagnostic classification, the models should ideally be usable to predict data from different setups. Whether it is done by training a rugged model with data from many setups or by a primary-replica strategy where models are developed on a 'primary' setup and the test data are generated on 'replicate' setups, this is only possible if the Raman spectra from different setups are consistent, reproducible, and comparable. However, Raman spectra can be highly sensitive to the measurement conditions, and they change from setup to setup even if the same samples are measured. Although increasingly recognized as an issue, the dependence of the Raman spectra on the instrumental configuration is far from being fully understood and great effort is needed to address the resulting spectral variations and to correct for them. To make the severity of the situation clear, we present a round robin experiment investigating the comparability of 35 Raman spectroscopic devices with different configurations in 15 institutes within seven European countries from the COST (European Cooperation in Science and Technology) action Raman4clinics. The experiment was developed in a fashion that allows various instrumental configurations ranging from highly confocal setups to fibre-optic based systems with different excitation wavelengths. We illustrate the spectral variations caused by the instrumental configurations from the perspectives of peak shifts, intensity variations, peak widths, and noise levels. We conclude this contribution with recommendations that may help to improve the inter-laboratory studies.COST (European Cooperation in Science and Technology)Portuguese Foundation for Science and TechnologyNational Research Fund of Luxembourg (FNR)China Scholarship Council (CSC)BOKU Core Facilities Multiscale ImagingDeutsche Forschungsgemeinschaft (DFG, German Research Foundation

Modelling of optical components made of liquid crystals and liquid crystalline polymers

Birefringent components, such as waveplates, Wollaston or Nomarski prisms, used in acoustic transducers can be made from Liquid Crystals or Liquid Crystalline Polymers (LCPs). This may result in better integration of optical setups and in reduced cost and complexity of these transducers. Since Wollaston or Nomarski prisms made from these materials differ from those made from crystalline materials, their key properties warrant closer examination. Modelling of light propagation in selected Nomarski prisms made from LCPs was performed using a birefringent ray-tracing algorithm. Obtained results were compared with those for corresponding prisms made from a crystalline material. Investigated Nomarski prisms made from LCPs have the plane of apparent splitting placed inside the component, which may be inconvenient for certain applications

Design and simulation of excitation laser system for

A system for in-situ Raman monitoring of thin film growth during Microwave Plasma Assisted Chemical Vapour Deposition (μPACVD) process was developed. Dedicated Raman probe system was designed for precise focusing of an excitation laser beam into the growing film. The probes have to be placed outside the reaction chamber (working distance about 20 cm) in order to avoid interference of the process by work of measurement devices (non-invasive measurements). Analysis and calculation supported by simulations based on Monte-Carlo ray-tracing method and Beam Propagation Method showed that glancing-incidence optical configuration is of the Raman system is the most sufficient one. Range of the most effective incidence angles of the excitation beam was determined. Shape and size of laser spot at the sample was determined. Correction of spherical aberrations by use of doublets was proposed to ensure efficient focusing of the excitation beam into the investigated film

Liquid crystalline optical components for application in optical sensing

Manufacturing process of Wollaston prisms using ZLI-1957 Liquid Crystal (LC) mixture and waveplates from RMS03-001 Liquid Crystalline Polymer (LCP) is presented. The Wollaston prism presented in the paper has the splitting angle of 0.37 mrad, and can be used in optical setups where very straight fringes are not required. Produced LCP waveplates exhibit retardation from 175.3 nm to 238.6 nm at the wavelength of 622 nm and show local retardation variations of $\pm 9{\%}$

Optical Investigation of Hematocrit Level in Human Blood

In this paper use of selected optical methods of a hematocrit measurement has been presented. Elaborated methods have numerous advantages: relatively simple configurations, potentially low cost and high resolution. Investigation confirmed their ability to determine the hematocrit value with appropriate measurement accuracy. Furthermore, simultaneous use of complementary optical methods can substantially increase measurement reliability, because low-coherence interferometric measurement is based on physical (mainly optical) properties of the investigated object, while Raman spectroscopy is based on study of its molecular composition

Detection of illicit chemicals by portable Raman spectrometer

The Raman spectrometers can be built as the portable devices and can be used in various places to detect illicit chemicals. This method has become popular due to deficiency of other fast methods that could be applied against terrorist attacks or could help police at their work. The Conception of a portable Raman spectrometer has been presented. The Description enclosures the presentation of the prepared device and its possible applications by presenting exemplary detection results