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The study concerns the behavior of optical and colorimetric properties of cadmium telluride semiconductor colloidal quantum dots covered with silica shell (CdTe/SiO2, core/shell) in an external constant electric field has been studied. To date, the electric field is known to lead mainly to quenching and red shift of the luminescence spectra of quantum dots; however, in most of the corresponding studies only the behavior of band-edge luminescence is considered. In this work, in addition to the luminescence due to interband transitions, the effect of the electric field on the trap-related luminescences of core/shell quantum dots is studied. Semiconductor nanocrystals were synthesized by colloidal chemistry methods. The product mixture was a solution of quantum dots in an aqueous medium. To investigate the optical properties of CdTe/SiO2 nanoparticles in an external electric field, a series of samples was fabricated on the basis of an optically passive cellulose film, in the pores of which quantum dots were embedded. The final sample was a cellulose film with quantum dots sandwiched between two glasses with transparent indium tin oxide electrodes. The strength of the constant electric field applied to such structures reached 140 kV/cm. Photoluminescence spectra of the investigated nanostructures were recorded using a CCD spectrometer. As a result of the experiments it was found that the presence and subsequent increase of the external electric field leads to quenching of the intensity of both band-edge and traprelated photoluminescence of quantum dots. This fact is associated with a decrease in the overlap between electron and hole wave functions under the action of the electric field. It is also shown that at moderate field strength there is a slight increase in the total photoluminescence intensity. This observation can be related to impeded charge carrier trapping. The demonstrated quenching of luminescence intensity is also consistent with the results of other authors who have shown a decrease in the absorption of quantum dots in external electric fields. The stability of colorimetric characteristics of the spherical nanoparticles in an external electric field has been demonstrated. The results of the study can be used for development of optoelectronic devices based on CdTe/SiO2 nanoparticles.

Food products change their quality during storage not only under the external impact, but also because they are complex in composition. As a result, food scientists look for new methods to control these internal changes. The research objective was to describe the changes in the physicochemical properties of apple puree during storage at elevated temperatures (40–60°C) and link them with the changes in the sensory profile. The study featured homogenized apple puree packaged in composite material and heated up to 40, 50, and 60°C. The colorimetric studies were conducted at 45°/0°, light source D65. The proton relaxation time and the water diffusion coefficient (impulse gradient method) were studied at a frequency of 20 MHz. The analysis of molecular dynamics involved the method of electron paramagnetic resonance of spin probes. The samples were cooled down to –70°C to measure the content of non-crystallizing water by the method of differential scanning calorimetry. The color change rate was constant and followed the zero-order kinetic reaction equation with an activation energy of 92 kJ/mol. The changes in color, proton relaxation, and sensory properties correlated when the samples were stored at 50 and 60°C. The analysis of the magnetic relaxation time, the diffusion coefficient of water, and the content of non-crystallizing water indicated that the main changes in the physical structure of the puree during heat treatment occurred as a result of the aggregation of apple cell fragments. These findings were confirmed by the optical microscopy. A prolonged exposure to 40–60°C affected the color, the relaxation of water protons, and the size of aggregates of apple cell fragments. It also affected the amount of water that did not crystallize at –70°C. The correspondence between the values of the activation energies was determined by the methods of colorimetry and proton relaxation. Therefore, the coloration and the water changes depended on the same processes. These physical and chemical properties can be used for quantitative assessment of apple puree under thermal treatment.

The brackish microalgae Dunaliella salina, being an extremophilic halophyte, is a promising object for biotechnological production. The aim of this work is to develop a methodology for non-destructive control of the development of a microalgae culture under conditions of balanced growth during periodic cultivation on plates. Before the start of the experiment, the microalgae culture was synchronized. The quantitative content of chlorophylls a and b, as well as carotenoids, was determined spectrophotometrically in alcohol extracts. During cultivation, time-lapse images were recorded on a smartphone camera. The basis of the colorimetric evaluation is the analysis of the time series of images in the RGB color model. It is shown that the ratio of colors correlates to a high degree with the content of the determined main plant pigments – chlorophylls and carotenoids, and with the data of spectrophotometric measurements of live suspensions. The changes in the blue channel are the most pronounced, the least being in the green channel. The logarithm of color intensity is linearly dependent on the degree of dilution of the culture. The developed method for real-time monitoring of the development dynamics of the D. salina microalgae culture makes it possible to build growth curves and solve multiparametric problems to optimize the cultivation of microalgae, including when working with large arrays of samples.

Any object can have many implementations in the form of digital images and any digital image can be processed many times increasing or decreasing accuracy and reliability. Digital colorimetry faces the need to work out issues of ensuring accuracy, metrological traceability and reliability. The purpose of this work was to generalize approaches to the description of multidimensional quantized spaces and show the possibilities of their adaptation to digital colorimetry. This approach will minimize the private and global risks in measurements.For color identification digital colorimetry uses standard color models and spaces. Most of them are empirical and are improved during the transition from standard to real observation conditions taking into account the phenomena of vision and the age of observers. From the point of view of measurement, a digital image can be represented by a combinatorial model of an information and measurement channel with the appearance of the phenomenon of a color covariance hypercube requiring a significant amount of memory for data storage and processing. The transition from the covariance hypercube to high-dimensional matrices and tensors of the first, second and higher ranks provides the prospect of optimizing the color parameters of a digital image by the criterion of information entropy.Tensor calculus provides opportunities for expanding the dynamic range in color measurements describing multidimensional vector fields and quantized spaces with indexing tensors and decomposing them into matrices of low orders.The proposed complex approach based on tensor calculus. According to this approach the color space is a set of directed vector fields undergoing sampling, quantization and coding operations. Also it is a dynamic open system exchanging information with the environment at a given level and to identify color with specified levels of accuracy, reliability, uncertainty and entropy.

Currently, neural network methods of fire detection have been used to monitor fires in forests. To date, such systems have been developed as the Prometheus project, the Fire Video Detector, and the Artificial Intelligence University method. These methods make it possible to determine a fire with an accuracy of more than 90 %, for which a combination of recurrent and light-line neural networks is used. The article proposes a method for improving the efficiency of neural network methods for determining fires in forests based on computer colorimetry. The use of this method makes it possible to increase the efficiency of neural network methods for detecting fire when using multiple cameras of a video surveillance system. Thus, the article presents a comparison of the performance of a convolutional neural network with and without the use of a colorimetric module. According to the results, the efficiency of work has increased by more than 20 %.

Lipid metabolism is crucial in physiology. In recent decades the model object Drosophila melanogaster has been actively used in the study of the fundamental issues of lipid metabolism and its disorders, including obesity, as well as in the search for therapeutic goals for the treatment of metabolic disorders in humans. Quick and accurate quantification of lipid content is an important step in solving these problems. For the first time the method of quantitative measurement of total lipids with the use of the sulfophosphovanillin (SPV) method was described by Zöllner and colleagues in 1962, and adapted for insects by Van Handel on females of the yellow fever mosquito Aedes aegypti. The advantages of this method compared to traditional gravimetric and chromatographic methods of analysis are the use of a small amount of biological material, lack of need for complex manipulations with the sample, its high sensitivity, reproducibility and simplicity of implementation with a minimum set of equipment. Here, a modification of the Van Handel protocol is described, which allows the method to be adapted for quantitative determination of total lipids for various organisms as exemplified a widely used model, D. melanogaster. To test the effectiveness of the modified method, we measured the content of total lipids in D. melanogaster females carrying hypomorphic mutations of the dilp6 and dfoxo insulin signaling pathway genes compared to the wild-type Canton-S line, and showed that dilp6 took part in the regulation of fat metabolism, while dfoxo did not. The results obtained emphasize the effectiveness of the colorimetric method with the use of SPV reaction and spectrophotometry for the quantitative analysis of total lipids.

Algorithms for the analysis of polychromatic interference patterns in images of thin stratified objects in optical microscopy are considered. The algorithms allow one to measure the thin-film optical thickness. A measurement method based on the comparison of colors of the interference image under study and a numerically simulated image is discussed. We discuss a mathematical model for the calculation and numerical simulation of interference patterns and algorithms for interference pattern processing. Color comparison in an RGB color model is described and limitations of such a method are shown. The feasibility of using a Lab color model is shown and algorithms of interference color comparison in this model are presented. Results of application of the presented algorithms to measuring the optical thickness of red blood cells in a blood smear are discussed. The estimation of the error and robustness of the proposed algorithms is conducted.

The results of investigation of luminous intensity distribution and color quantities of LED lamps of different design are presented. It is demonstrated that measurement of angular luminous intensity distribution is more accurately indicates characteristics of LED lamp emission than measured luminous intensity value alongside its mechanical axis. It is established that color quantities of investigated LED lamps declared by manufacturer are different from values defined by applicable normative documents.

Porous anodic aluminium oxide must be widely used in new types of micro- and nanoelectronics devices, including those operating at elevated temperatures. Therefore, it is of great importance to study the behaviour of anodic alumina fi lms upon heating. This paper studies phase and morphological changes in the fi lms of anodic aluminium oxide from sodium hydroxide solutions which occur under thermal treatment. The study uses a set of physical and mathematical methods, including colorimetric, x-ray phase and fractal analyses. Colorimetric analysis showed that after annealing, the values of refl ection coeffi cients reduced from 65 to 57%, which may be due to structural changes. The samples of initial and annealed anodic aluminium oxide fi lms were studied by X-ray phase analysis. It has been established that annealing anodized samples at a temperature of 500 ° C for 40 minutes leads to a number of changes in the hydrated alumina forms. Low-temperature modifi cation of aluminium oxide γ - Al2О3 is formed by thermal decomposition of “hydroxide precursors”. The study proposes an explanation of the thermally induced phase transformations of porous alumina which is based on the statement about different crystallization rate of Al2O3 enriched with electrolyte anions and anion-free oxide. The interrelation between changes in micro- and macrostructures was determined by comparative fractal analysis of images of anodized samples before and after annealing. The calculation showed that the fractal dimension of the surface increased from 2.7621–2.8724 (initial samples) to 2.8193–2.8824 (after annealing). The process of annealing involves the dehydration of aluminium hydroxides accompanied by the destruction of primary crystallites, the formation of platelet particles, and an increase in the specifi c surface area. The interrelation between micro- and macrostructures is of great importance for understanding the mechanisms of the formation and interdependent transitions of aluminium hydroxides and aluminium oxides. The detailed study of these mechanisms will make it possible to obtain aluminium oxides with set properties.

The review presents an analysis of modern methods and instruments for performing nonspecific detection of pathogenic biological agents in environmental objects. Discussed are technological characteristics of application of these methods for the detection of biological substances of protein nature in samples. The spectrum of means for non-specific PBA detection includes home-produced and foreign field devices based on protein contamination indication using various colorimetry variants. Technologies for remote and direct monitoring of environment for the presence of aerosols of biological nature are represented by hybrid lidar systems (biolidars) and biodetectors. For PBA nucleic acids tracing, the complexes based on DNA molecule binding with fluorophore with further fluorescence detection are described. Given are the examples of chemiluminescent analysis application in the developed automatic impurity detectors, as well as systems using bioluminescence. Based on the literature data analysis, put forward is a possible algorithm for indication of pathogenic biological agents when carrying out monitoring of the environment in zones of possible emergency situation occurrence and mass events holding.

Розроблено новий гібридний органополімерний сорбент на основі метилсилікатної кислоти (МСК), модифікованої 3-метил(або 3-феніл)-2,6-димеркапто-1,4-тіопіроном (Н2М або Н2Ф) та полівінілпіролідоном (ПВП), для селективного та чутливого сорбційно-кольорометричного або тест-визначення мікродомішок Pd(II). Визначено сорбційну ємність модифікованих сорбентів МСК−ПВП−Н2М та МСК−ПВП−Н2Ф за Pd(II): 6.6 та 3.9 мг/г відповідно. Концентрація Pd(II) може бути оцінена візуально за допомогою індикаторної трубки (d = 0.4 см, mcорб. = 0.10 г, Vоб. = 0.2 мл/хв) або кольорометричним методом в інтервалах концентрацій 0.01−16 мкг/мл або 1−45 мкг/мл для індикаторних порошків МСК−ПВП−Н2Ф або МСК−ПВП−Н2М з межею виявлення 0.005 мкг/мл або 0.1 мкг/мл відповідно. Правильність розроблених методик перевірено методом «введено–знайдено» у процесі кольорометричного визначення Pd(II) у зразках природної води (sr ≈ 8%) та візуально-тестового з використанням індикаторної трубки на модельних розчинах переробки каталізатора (sr < 5%).

The developed method of Objects photometric and colorimetric characteristics measurements on the base of digital cameras are described. Application of the initial samples those are realized as the support of the control points on a non-radiant Object or as primary sources on a radiant Object will provide the metrological traceability and also build a conditional scale in each colour channel and expand the dynamic range of measurements by increasing the reliability and accuracy of measurement results.

One of the important factors for creating a beautiful smile is the color of the teeth, which for most people has a more important role than anatomical characteristics. The exact reproduction of the color of the tooth affects the appearance and psycho-emotional state of the patient. The purpose of this work is to review domestic and foreign literature on methods for determining the color of teeth. Methods for determining color are divided into visual, spectrophotometric, colorimetric, digital photo analysis and computer method. The most common in the practice of a dentist is visual, which is based on comparing the examined tooth with color templates. Determination of the color of teeth using scales does not give a reliable result, which is due to the small number of shades in the colors, the phenomenon of metamerism, the impossibility of converting the obtained data into digital values, etc. The hardware method for determining the color of teeth compensates for the disadvantages of the visual and has a high adaptability, which requires many interrelated factors. Due to the complexity and high cost, the devices are used mainly for research purposes. Currently, innovative methods for determining the color of teeth, based on digital and computer analysis, are being actively developed. Thus, hardware methods for determining the color of teeth significantly increase the accuracy of choosing the shade of a future aesthetic restoration or orthopedic construction, excluding subjective factors, however, they require mandatory certification. Correct color assessment and identification helps to reduce costly re-treatments and reduce warranty costs. Despite this, visual methods using scales remain in demand among practicing doctors, due to their low cost and ease of use. The accuracy of determining the color of teeth in this case depends on the professionalism of the dentist, as well as on the correctness of the photo protocol.

The goal of this work was to demonstrate the results of the development of the enzyme-linked immunosorbent tests with chemiluminescence detection and colorimetric detection of specific viral antigens and antibodies for identifying the avian influenza and the Newcastle disease viruses: high sensitivity and specificity of the immuno- chemiluminescence assay, which are 10-50 times higher than those of the ELISA colorimetric method. The high effectiveness of the results and the automation of the process of laboratory testing (using a luminometer) allow these methods to be recommended for including in primary screening tests for these infectious diseases.

The homeostasis of basic microelements (Fe, Cu and Zn) is ultimately important for normal functioning of organism. The article presents the data concerning the detection of these metals both in blood serum and urine of patients with anemia of different etiology. The indicators of excretion can provide additional information for diagnostics and needed therapy. The article describes in details simple colorimetric methods of detection of mentioned metals in urine. It is demonstrated that under anemia the positive balance of cuprum is noted. This occurrence can be a possible cause of coagulation complications.

Association and degradation of protein complexes play essential role in a majority of normal and pathologic processes, which take place in living cell. Studying the underlying mechanisms of those interactions would give deeper understanding of specific causes of disease progression and would allow developing new therapeutic strategies. The majority of technical approaches currently used for detecting protein association include in vitro protein extraction and purification, whereas more relevant results require methods that can be used in vivo. One of a few approaches for in vivo protein association detection is based on reporter protein fragment complementation. Reporter systems based on protein complementation rely on reconstitution of reporter protein fluorescent or enzymatic activity which occurs upon reassociation of protein fragments and could be measured by colorimetry, luminometry or fluorimetry. Protein complementation is widely used to develop reporter systems for analysis of protein interactions, for functional dissection of signal transduction pathways and for performing high-throughput screenings to discover new protein interaction partners. Currently developed approaches that utilize protein fragment complementation have possibilities that extend far beyond simple detection of interaction in a pair of proteins.

The effect of cations, anions and specific chemical reagents: 1-[3-(dimethylamino) propyl]-3-ethylcarbodiimide methiodide, EDTA, o-phenanthroline, dithiotreitol, L-cysteine, beta-mercaptoethanol, p-chlormercurybenzoate (p-ChMB), N-ethylmaleimide on the activity of alpha-L-rhamnosidase of Eupenicillium erubescens has been investigated. The essential role of Ag+ and Hg2+ which inhibit the alpha-L-rhamnosidase activity by 47-73% has been shown. Whereas L-cysteine exhibits the protective effect, rhamnose in concentration of 1-5 mM does not protect the enzyme from negative effect of Ag+ and Hg2+. Basing on the inhibitory and kinetic analysis it was supposed that the carboxyl group of C-terminal aminoacid and imidazole group of histidine take part in the catalytic action of alpha-L-rhamnosidase. It was assumed that sulphydryl groups took part in catalysis, carried out by alpha-L-rhamnosidase of E. erubescens, since the activity of alpha-L-rhamnosidase inhibited by p-ChMB and thiol reagents such as dithiothreitol, L-cysteine, beta-mercaptoethanol did not remove its inhibitory action.

Patients with obesity and type 2 diabetes mellitus are known to have hypoadiponectinemia partially compensated by switching to low-caloric diet. Reduction of the body mass results in the proportional increase of the adiponectin level and decreased severity of insulin resistance.

Aim: To study the role of free radical processes (FRP) in the development of involutional skin changes and their correction., Subjects and Methods: One hundred and twenty patients aged 18 to 74 years with various degrees of involutional facial and cervical skin changes were examined. Clinical and laboratory assessments were made over time. The oxygen and lipid peroxidase parameters of FRP were estimated; objective and subjective visualization, Doppler flowmetry of the facial skin, and colorimetric study of the skin color spectrum were done., Results: The imbalance between oxygen and lipid peroxide components of FRP was found to increase with advancing age. These processes correlate with the severity of involutional skin changes and objectify the early use of energy-correcting therapy (ECT). The incorporation of ECT with cytoflavin positively affects FRP values and clinical and instrumental findings of involutional facial and cervical skin changes, by improving microcirculation. The patients with first-second degree involutional skin changes achieved the best results., Conclusion: The findings permit cytoflavin to be recommended as one of the components of therapy aimed to stabilize intradermal exchange processes as part cosmetic manipulations in aesthetic medicine.

A specific, fast, and easy method for revelation of active plate producers of L-asparaginase using differential medium on the basis of LB or M9 with 1.5% agar was developed. Each 100 ml of LB or M9 medium additionally contained 6-7 ml ofglycerol, 4 g of L-asparagine, 0.2 g of CaCO3, and diagnostic components: 3 ml of 0.2 M CuSO4 x 5H2O and 2.5 ml of 0.1 M K3Fe(CN)6, pH 7.6-7.8. The results were counted 12-20 or 24-48 h after strain growth at 37 degrees C in corresponding mediums. Red color of colonies and colored zone around them showed the ability of the strain under study to destroy asparaginic complexes. The recommended method allows revealing bacterial strains producing L-asparaginase with specific activity of not less than 0.1-3.0 MU/mg of protein.

The article presents an analysis of practical experience and the author presents the methodology of glycolized hemoglobin (GH) determination in the clinic of internal diseases. 1220 patients with diabetes mellitus (DM) and without clinically evident DM have been examined during different period of time. Different techniques were used to determine GH. they are the following: photocolorimetric, chromatographic, and electrophoretic. It were useful during interpretation of GH to consider not absolute value of GH, but also change of its level in dynamics for a long period of time, i.e., art monitoring.

Previously, significant increase in survival in locally-advanced rectal cancer as a result of heated intraoperative intraperitoneal chemotherapy was reported. Our study used cisplatin 0.5 mg/ml (0.05 per cent solution) in the culture of pharyngeal epidermoid carcinoma (PEC) cells (HEP-2) and A-549 culture of lung carcinoma cells. The number of viable cells was estimated colorimetrically after 24 and 48 hr incubation. 50%-rise in inhibition of culture growth was assumed to be biologically significant. Forty-eight hours after inoculation, single dose of cisplatin 8 mg/kg was injected in mice bearing transplanted lung carcinoma of Lewis (LLC). That was followed by death of tumor cells. Preheating (45 deg. C, 1 hr) did not influence either the cytostatic or therapeutic effect of cisplatin in vivo.That procedure inhibited tumor growth by 7-8% and the effect did not wear off until day 11 or longer. Survival in LLC-bearing mice rose by 26% which pointed to the advantages offered by heated cytostatic chemotherapy.