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Investigation of silver nanoparticles embedded in extracted gelatins from camel, bovine, and fish bones for possible use in radiation dosimetry

Alrashidi Thaar K., Aljuhani Alwaleed, Almugaiteeb Faisal, Badi Nacer, Al-Aoh Hatem A., Alghamdi Saleh A., Alsharari Abdulrhman M, Alzahrani Ahmed Obaid M, Almalki Khaled

Materials Science Poland

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2023

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Vol. 41, No. 4

1--12

EN

Gelatins from camel, bovine, and fish bones were successfully extracted by using chemical pretreatment and heating methods. The bones were demineralized for 3 days at ambient temperature using hydrochloric acid solutions (0.5–1 M), and the collagen was partially hydrolyzed by preheating in distilled water at 75–80°C for 3 h, followed by extraction temperature at 90°C for 1 h. Free-standing films of gelatin entrained with silver nanoparticles (Gel/AgNPs) at low concentrations (1.25, 2.5, and 5 mM) were synthesized as radiation dosimeters. A high-energy ultrasonic homogenizer was used to dissolve the gelatin in distilled water and to disperse the AgNPs in the gelatin. The nanocomposites’ morphology and crystallinity were investigated using scanning electron microscopy (SEM), optical absorption, and Fourier transform infrared (FTIR) spectroscopies. Dose enhancement was assessed using X-ray irradiations with beam energies below and above silver K-edge. The beam was configured by setting the X-ray generator at 15, 25.5, and 35 kV potential and a beam current of 1 mA. An X-ray detector is used to detect the number of electrons after passing through Gel/AgNPs samples. The use of AgNPs embedded in gelatin caused the enhancement of X-ray radiation absorption, and the highest percentage of linearity for the dosimeter was found to be 90% in the optical range of 395 nm to 425 nm. The preliminary results demonstrated that Gel/AgNPs material may be used in radiation dosimetry for low-energy radiotherapy sources.

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Tuning the Laser Ignition Properties of Nitrocellulose-Nitroglycerine-Hexogen Propellants via Incorporation of Carbon Nanotubes

Shi Xianrui, Jia Yongjie, Chen Linyu, Tian Lu, Shen Jinpeng, Pei Chonghua

Central European Journal of Energetic Materials

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2021

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Vol. 18, no. 3

385--404

EN

Near infrared laser ignition is challenging owing to the poor near infrared laser absorption of nitrocellulose-nitroglycerine-hexogen (NC-NG-RDX) propellants. Less than 1 wt.% of carbon nanotubes (CNTs) were uniformly dispersed into the NC-NG-RDX propellants to tune its near infrared laser ignition property. The effects of CNTs on the thermal decomposition, near infrared light absorption and thermal conductivity of NC-NG-RDX propellants were studied. The near infrared laser ignition property of NC-NG-RDX propellants doped with CNTs were investigated compared with raw NC-NG-RDX propellant. The decomposition property and thermal conductivity of NC-NG-RDX propellants doped with CNTs were little changed due to the small quantity of CNTs. The laser reflectivity of the composite propellants decreased obviously as the content of CNTs was increased because of the high laser absorption property of CNTs. The laser ignition performance of the composites propellants is substantially improved by the incorporation of 0.5 wt.% or less CNTs and the successful ignition time decreases remarkably. Higher CNT content, such as 0.75 wt.% can lead to failure of laser ignition due to the excessive laser absorption efficiency and heating rate of the radiated region of the composite propellants together with inefficient deflagration. Our research reveals that the appropriate proportion of CNTs can potentially be used as a laser sensitizer for realizing effective infrared laser ignition of NC-NG-RDX propellants.

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Poradnik dla początkującego witrażysty. Malowanie witraża klasycznego. Odcinek 22. Witraż nie musi pochłaniać dużo światła

Bochacz A., Bochacz A.

Szkło i Ceramika

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2017

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R. 68, nr 5

47

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Inherent optical properties and remote sensing reflectance of Pomeranian lakes (Poland)

Ficek D., Meler J., Zapadka T., Woźniak B., Dera J.

Oceanologia

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2012

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No. 54 (4)

611-630

EN

This paper describes the results of comprehensive empirical studies of the inherent optical properties (IOPs), the remote sensing reflectance Rrs(λ) and the contents of the principal optically active components (OAC) i.e. coloured dissolved organic matter (CDOM), suspended particulate matter (SPM) and chlorophyll a, in the waters of 15 lakes in Polish Pomerania in 2007-2010. It presents numerous spectra of the total absorption a(λ) and scattering b(λ = bp(λ) of light in the visible band (400-700 nm) for surface waters, and separately, spectra of absorption by CDOM aCDOM(λ) and spectra of the mass-specific coefficients of absorption ap*(SPM)(λ) and scattering bp*(SPM)(λ) by SPM. The properties of these lake waters are highly diverse, but all of them can be classified as Case 2 waters (according to the optical classification by Morel & Prieur 1977) and they all have a relatively high OAC content. The lakes were conventionally divided into three types: Type I lakes have the lowest OAC concentrations (chlorophyll concentration Ca = (8.76 š 7.4) mg m-3 and CDOM absorption coefficients aCDOM(440) = (0.57 š 0.22) m-1 (i.e. mean and standard deviation), and optical properties (including spectra of Rrs(?) resembling those of Baltic waters. Type II waters have exceptionally high contents of CDOM (aCDOM(440) = (15.37 š 1.54) m-1), and hence appear brown in daylight and have very low reflectances Rrs(?) (of the order of 0.001 sr-1). Type III waters are highly eutrophic and contain large amounts of suspended matter, including phytoplankton ((CSPM = (47.0 š 39.4) g m-3, Ca = (86.6 š 61.5) mg m-3; aCDOM(440) = (2.77 š 0.86) m-1). Hence the reflectances Rrs(?) of these type of waters are on average one order of magnitude higher than those of the other natural waters, reaching maximum values of 0.03 sr-1 in ? bands 560-580 nm and 690-720 nm (see Ficek et al. 2011). The article provides a number of empirical formulas approximating the relationships between the properties of these lake waters.

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Inherent optical properties of suspended particulate matter in the southern Baltic Sea

Woźniak S.B., Meler J., Lednicka B., Zdun A., Stoń-Egiert J.

Oceanologia

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2011

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No. 53 (3)

691-729

EN

The inherent optical properties (IOPs) of suspended particulate matter and their relations with the main biogeochemical characteristics of particles have been examined in the surface waters of the southern Baltic Sea. The empirical data were gathered at over 300 stations in open Baltic Sea waters as well as in the coastal waters of the Gulf of Gdańsk. The measurements included IOPs such as the absorption coefficient of particles, absorption coefficient of phytoplankton, scattering and backscattering coefficients of particles, as well as biogeochemical characteristics of suspended matter such as concentrations of suspended particulate matter (SPM), particulate organic matter (POM), particulate organic carbon (POC) and chlorophyll a (Chl a). Our data documented the very extensive variability in the study area of particle concentration measures and IOPs (up to two orders of magnitude). Although most of the particle populations encountered were composed primarily of organic matter (av. POM/SPM = ca 0.8), the different particle concentration ratios suggest that the particle composition varied significantly. The relations between the optical properties and biogeochemical parameters of suspended matter were examined. We found significant variability in the constituent-specific IOPs (coefficients of variation (CVs) of at least 30% to 40%, usually more than 50%). Simple best-fit relations between any given IOP versus any constituent concentration parameter also highlighted the significant statistical errors involved. As a result, we conclude that for southern Baltic samples an easy yet precise quantification of particle IOPs in terms of the concentration of only one of the following parameters - SPM, POM, POC or Chl a - is not achievable. Nevertheless, we present a set of best statistical formulas for a rough estimate of certain seawater constituent concentrations based on relatively easily measurable values of seawater IOPs. These equations can be implemented in practice, but their application will inevitably entail effective statistical errors of estimation of the order of 50% or more.

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Orientational behaviour of some homologues of 4-n-pentyl-phenylthio-4'-n-alkoxybenzoate doped with dichroic dye

Bauman D., Zięba A., Mykowska E.

Opto-Electronics Review

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2008

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Vol. 16, No. 3

244-250

EN

The long-range orientational order of three members of 4-n-pentylphenylthio-4'-n-alkoxybenzoate (nS5) series doped with a dichroic dye was studied by means of electronic absorption and fluorescence measurements. The order parameters and as well as the orientational distribution function were determined on the basis of absorption and emission spectra of linearly polarized light recorded as a function of temperature in the nematic, smectic A, and smectic C phases. An influence of the dye molecular structure on the orientational order of the dye/liquid crystal mixture was observed. Moreover, the dependence of the order parameter values on the length of the alkoxy chain in liquid crystal molecules was found. It was shown that the order parameter , obtained from fluorescence measurements, can be helpful in recognizing the second-order or weakly first-order transitions between various liquid crystalline phases.

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Spectra of light absorption by phytoplankton pigments in the Baltic; conclusions to be drawn from a Gaussian analysis of empirical data

Ficek D., Kaczmarek S., Stoń-Egiert J., Woźniak B., Majchrowski R., Dera J.

Oceanologia

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2004

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No. 46 (4)

533-555

EN

Analysed by differential spectroscopy, 1208 empirical spectra of light absorption apl(?) by Baltic phytoplankton were spectrally decomposed into 26 elementary Gaussian component bands. At the same time the composition and concentrations of each of the 5 main groups of pigments (chlorophylls a, chlorophylls b, chlorophylls c, photosynthetic carotenoids and photoprotecting carotenoids) were analysed in 782 samples by HPLC. Inspection of the correlations between the intensities of the 26 elementary absorption bands and the concentrations of the pigment groups resulted in given elementary bands being attributed to particular pigment groups and the spectra of the mass-specific absorption coefficients established for these pigment groups. Moreover, balancing the absorption effects due to these 5 pigment groups against the overall absorption spectra of phytoplankton suggested the presence of a sixth group of pigments, as yet unidentified (UP), undetected by HPLC. A preliminary mathematical description of the spectral absorption properties of these UP was established. Like some forms of phycobilins, these pigments are strong absorbers in the 450-650 nm spectral region. The packaging effect of pigments in Baltic phytoplankton was analysed statistically, then correlated with the concentration of chlorophyll a in Baltic water. As a result, a Baltic version of the algorithm of light absorption by phytoplankton could be developed. This algorithm can be applied to estimate overall phytoplankton absorption spectra and their components due to the various groups of pigments from a knowledge of their concentrations in Baltic water.

8

Chlorophyll fluorimetry as a method for studying light absorption by photosynthetic pigments in marine algae

Matorin D. N., Antal T. K., Ostrowska M., Rubin A. B., Ficek D., Majchrowski R.

Oceanologia

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2004

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No. 46 (4)

519-531

EN

Using laboratory cultures of algae and natural phytoplankton populations from Nhatrang Bay (South China Sea), the relationship between the chlorophyll fluorescence F0, the chlorophyll a concentration Ca and light absorption capacities of algae cells was studied. It is shown that the ratio F0/Ca depends mainly on the species composition of the algae population; hence, the concentration Ca can be measured with the fluorescence method with acceptable accuracy only when the species composition of algae populations varies over a rather narrow range. The fluorescence F0 can, however, be a good index of the total absorption capacities of different phytoplankton species, because the intensity of F0 depends on the sum total of light absorbed by all photosynthetic pigments in a plant cell. Thus, the fluorescence F0 measures not only the concentration of chlorophyll a, but that of all photosynthetic pigment concentrations.

9

Modelling light and photosynthesis in the marine environment

Woźniak B., Dera J., Ficek D., Majchrowski R., Ostrowska M., Kaczmarek S.

Oceanologia

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2003

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No. 45 (2)

171-245

EN

The overriding and far-reaching aim of our work has been to achieve a good understanding of the processes of light interaction with phytoplankton in the sea and to develop an innovative physical model of photosynthesis in the marine environment, suitable for the remote sensing of marine primary production. Unlike previous models, the present one takes greater account of the complexity of the physiological processes in phytoplankton. We have focused in particular on photophysiological processes, which are governed directly or indirectly by light energy, or in which light, besides the nutrient content in and the temperature of seawater, is one of the principal limiting factors. To achieve this aim we have carried out comprehensive statistical analyses of the natural variability of the main photophysiological properties of phytoplankton and their links with the principal abiotic factors in the sea. These analyses have made use of extensive empirical data gathered in a wide diversity of seas and oceans by Polish and Russian teams as well as by joint Polish-Russian expeditions. Data sets available on the Internet have also been applied. As a result, a set of more or less complex, semi-empirical models of light-stimulated processes occurring in marine phytoplankton cells has been developed. The trophic type of sea, photo-acclimation and the production of photoprotecting carotenoids, chromatic acclimation and the production of various forms of chlorophyll-antennas and photosynthetic carotenoids, cell adaptation by the package effect, light absorption, photosynthesis, photoinhibition, the fluorescence effect, and the activation of PS2 centres are all considered in the models. These take into account not only the influence of light, but also, indirectly, that of the vertical mixing of water; in the case of photosynthesis, the quantum yield has been also formulated as being dependent on the nutrient concentrations and the temperature of seawater. The bio-optical spectral models of irradiance transmittance in case 1 oceanic waters and case 2 Baltic waters, developed earlier, also are described in this paper. The development of the models presented here is not yet complete and they all need continual improvement. Nevertheless, we have used them on a preliminary basis for calculating various photosynthetic characteristics at different depths in the sea, such as the concentration of chlorophyll and other pigments, and primary production. The practical algorithm we have constructed allows the vertical distribution of these characteristics to be determined from three input data: chlorophyll a concentration, irradiance, and temperature at the sea surface. Since all three data can be measured remotely, our algorithm can be applied as the "marine part" of the remote sensing algorithms used for detecting marine photosynthesis.

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Giant absorption of light in quasi-zero-dimensional structures

Pokutnyi S.I., Salejda W., Jacak L., Misiewicz J., Tyc M.

Optica Applicata

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2001

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Vol. 31, nr 3

659-671

EN

We present a theory of electromagnetic field interaction with one-particle localized charged states emerging near the small spherical semiconductor or dielectric particles of radius a placed in dielectric matrices. In the framework of the dipole approximation we predict theoretically giant magnitudes of: 1) transitions oscillator strengths, and 2) the resonance light absorption cross-section sigma /sub aba/( omega , a). We suggest that these peculiarities can be observed experimentally in the systems under consideration. We also discuss the dependence of sigma /sub abs/ ( omega ,a) and the scattering cross-section sigma /sub abs/( omega ,a) on light frequency and radius a of one-particle localized excitations under different physical circumstances.

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Parameterization of light scattering for solving the inverse problem of determining the concentrations of the principal light scattering and absorbing admixtures in shelf waters

Pelevin V. N., Rostovtseva V. V.

Oceanologia

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2001

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No. 43 (4)

479-485

EN

A method for estimating the water backscattering coefficient was put forward on the basis of experimental data of diffuse attenuation coefficient for downwelling irradiance and irradiance reflectance. Calculations were carried out for open sea waters of different types and the spectral dependencies were found ("anomalous" spectra) and explained. On this basis, a new model of light backscattering on particles in the sea is proposed. This model may be useful for modelling remote sensing reflectance spectra in order to solve the inverse problems of estimating the concentration of natural admixtures in shelf waters

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Modelling of bio-optical parameters of open ocean waters [commun.]

Pelevin V. N., Rostovtseva V. V.

Oceanologia

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2001

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No. 43 (4)

469-477

EN

An original method for estimating the concentration of chlorophyll pigments, absorption of yellow substance and absorption of suspended matter without pigments and yellow substance in detritus using spectral diffuse attenuation coefficient for downwelling irradiance and irradiance reflectance data has been applied to sea waters of different types in the open ocean (case 1). Using the effective numerical single parameter classification with the water type optical index m as a parameter over the whole range of the open ocean waters, the calculations have been carried out and the light absorption spectra of sea waters tabulated. These spectra are used to optimize the absorption models and thus to estimate the concentrations of the main admixtures in sea water. The value of m can be determined from direct measurements of the downward irradiance attenuation coefficient at 500 nm or calculated from remote sensing data using the regressions given in the article. The sea water composition can then be readily estimated from the tables given for any open ocean area if that one parameter m characterizing the basin is known.