Porównanie składu chemicznego dostępnych w handlu wybranych wód mineralnych ze składem wody wodociągowej miasta Kielce

Comparative analysis of the chemical composition of the commerce mineral and spring waters to tap water in the district city of Kielce has been presented in this paper. The research has been done using the latest analytical equipment which was stocked with ion chromatograph 883 Basic IC plus and spectrometer Optima 8000. The PHREEQC 2.17 program has been used in order to calculate the ion balances and SI index.W pracy porównano skład chemiczny dostępnych w handlu wybranych wód mineralnych z wodą wodociągową miasta Kielce. Badaniami objęto wody mineralne niskomineralizowane: Kroplę Beskidu, Żywiec Zdrój i Dobrowiankę; średniomineralizowane: Nałęczowiankę, Nestle Aquarel i Cisowiankę oraz wysokomineralizowane: Staropolankę 2000, Muszyniankę i Piwniczankę. Oznaczenia wykonano, posługując się najnowocześniejszym sprzętem analitycznym, tj. chromatografem jonowym 883 Basic IC plus firmy Metrohm oraz spektrometrem emisyjnym ze wzbudzeniem, w indukowanej plaźmie, Optima 8000 firmy Perkin Elmer. Bilanse jonowe oraz wartość indeksów stabilności uzyskano, wykorzystując programy Exel oraz PHREEQC 2.17

SPR Effect Controlled by an Electric Field in a Tapered Optical Fiber Surrounded by a Low Refractive Index Nematic Liquid Crystal

This paper presents the influence of a thin metal layer deposition on the surface of a tapered optical fiber surrounded by a low liquid crystal, on light propagation inside the taper structure. In this research, three types of liquid crystal cells were under investigation: orthogonal, parallel, and twist. They differed by the rubbing direction of the electrodes in relation to the fiber axis determining the initial molecule arrangement inside the cell. Gold films with thickness d = 30 nm were deposited on the tapered fiber surface in the tapered waist area. Cells including a tapered optical fiber with no metallic layer were also examined and presented as a reference. All measurements were performed at room temperature for a different steering voltage U from 0 to 200 V, with and without any amplitude modulation with a frequency f = 5 Hz, and the wavelength λ range from 550 to 1200 nm. As a result, the resonant peaks were obtained, which depends on a liquid crystal cell type and steering voltage, as well. This paper shows the possibility of sensing the change of applied voltage by the constructed system. During measurements, additional effects as signal overlapping and intermodal interference were observed reducing measured voltage value. In the future, the improved, similar systems that will have a better response could be used as a sensor of factors to which liquid crystal (LC) will be sensitive, especially temperature and electric field

Kompozyty ciekłokrystaliczne do punktowych pomiarów temperatury

The application of cholesteric liquid crystals and composites containing them for visualization of thermal field and temperature measurement is very well known. Despite all disadvantages as limited precision and adhesion to the studied surface, this method is still of interest. In this work, we present the results of preliminary studies on polymer-dispersed cholesteric liquid crystal (PDCLC) composites designed for visualization and measurement of point temperature changes which can be used in medical diagnostics. Basing on the results of former studies, the perspective PDCLC preparation method as well as high-performance liquid-crystalline chiral nematics were obtained and applied. The microencapsulation in poly(vinyl, alcohol) has been chosen as the method of PDCLC preparation while as liquid-crystalline materials the chiral nematics were adopted.Zastosowanie cholesterycznych ciekłych kryształów i kompozytów je zawierających do wizualizacji pól cieplnych i pomiaru temperatury jest dobrze znane. Niezależnie od niedogodności, jakimi są ograniczona precyzja i adhezja do badanego podłoża, metoda ta jest ciągle interesująca. Niniejsza praca przedstawia wyniki wstępnych badań nad kompozytami typu PDCLC, zawierającymi cholesteryczne ciekłe kryształy, a przeznaczonymi do wizualizacji i pomiaru punktowych zmian temperatury, co może znaleźć zastosowanie w diagnostyce medycznej. W oparciu o wyniki poprzednich badań wytypowano i zastosowano perspektywiczną metodę otrzymywania kompozytów oraz nowe materiały ciekłokrystaliczne. Wykorzystano dyspergowanie w wodnym roztworze poli(alkoholu winylowego) ciekłokrystalicznych nematyków chiralnych

Enhancement of the SPR Effect in an Optical Fiber Device Utilizing a Thin Ag Layer and a 3092A Liquid Crystal Mixture

This paper is a continuation of previous work and shows the enhancement of the surface plasmon resonance effect in a tapered optical fiber device. The study investigated liquid crystal cells containing a tapered optical fiber covered with a silver nanolayer, surrounded by a low refractive index liquid crystal in terms of the properties of light propagation in the taper structure. Silver films with a thickness of d = 10 nm were deposited on the tapered waist area. Measurements were performed at room temperature; liquid crystal steering voltage U from 0 to 200 V, with and without any amplitude modulation with a frequency of f = 5 Hz, and the wavelength λ ranged from 550 to 1200 nm. A significant influence of the initial arrangement of liquid crystals molecules on light propagation was observed. Three types of liquid crystal cells—orthogonal, parallel, and twist—were considered. During the measurements, resonant peaks were obtained—the position of which can also be controlled by the type of liquid crystal cells and the steering voltage. Based on the obtained results, the best parameters, such as highest peak’s width reduction, and the highest SNR value were received for twisted cells. In addition, the present work was compared with the previous work and showed the possibility of improving properties of the manufactured probes, and consequently, the surface plasmon resonance effect. In the presented paper, the novelty is mainly focused on the used materials as well as suitable changes in applied technological parameters. In contrast to gold, silver is characterized by different optic and dielectric properties, e.g., refractive index, extension coefficient, and permittivity, which results in changes in the light propagation and the SPR wavelengths

Mesomorphic, optic, dielectric, elastic and viscous properties of multi-component isothiocyanato mixtures

Four nematic mixtures A, B, C and D, comprising alkylphenylethylphenyl isothiocyanates, alkylcyclohexylphenylisothiocyanates, biphenyl and terphenyl derivatives, respectively, were prepared and their physical properties investigated, including birefringence, static permittivity, dielectric anisotropy, splay elastic constant and rotational and bulk viscosity. All the mixtures exhibited a broad nematic range ($\sim 100^{\circ}$), moderate birefringence ($\Delta n \sim 0.23-0.26$), positive dielectric anisotropy ($\Delta \epsilon \sim 8-10$ ) and low rotational viscosity. The mixtures showed improved performance in birefringence and viscosity properties in comparison with the widely used commercial mixture E7. As far as display performance is concerned, mixture D was found to be the most valuable. A comprehensive study of the usefulness of the biphenyl and terphenyl derivatives as dopants in mixtures has also been conducted with a view to improving their physical parameters to give faster electro-optical response times in liquid crystal display devices. Application of these mixtures is envisaged in high-speed photonics and liquid crystal display devices