Nonlocal Optics of Plasmonic Nanowire Metamaterials

We present an analytical description of the nonlocal optical response of plasmonic nanowire metamaterials that enable negative refraction, subwavelength light manipulation, and emission lifetime engineering. We show that dispersion of optical waves propagating in nanowire media results from coupling of transverse and longitudinal electromagnetic modes supported by the composite and derive the nonlocal effective medium approximation for this dispersion. We derive the profiles of electric field across the unit cell, and use these expressions to solve the long-standing problem of additional boundary conditions in calculations of transmission and reflection of waves by nonlocal nanowire media. We verify our analytical results with numerical solutions of Maxwell's equations and discuss generalization of the developed formalism to other uniaxial metamaterials

The room temperature phosphine-free synthesis of near-infrared emitting HgSe quantum dots

Luminescent mercury selenide (HgSe) quantum dots have been synthesised by a phosphine-free method using oleic acid as a capping agent. The modification of experimental conditions such as temperature resulted in particles of various sizes (15–100 nm) and morphologies not previously seen in HgSe, with emission tuneable between 1000 nm and 1350 nm

Boundary effects in finite size plasmonic crystals: Focusing and routing of plasmonic beams for optical communications

Plasmonic crystals, which consist of periodic arrangements of surface features at a metal-dielectric interface, allow the manipulation of optical information in the form of surface plasmon polaritons. Here we investigate the excitation and propagation of plasmonic beams in and around finite size plasmonic crystals at telecom wavelengths, highlighting the effects of the crystal boundary shape and illumination conditions. Significant differences in broad plasmonic beam generation by crystals of different shapes are demonstrated, while for narrow beams, the propagation onto the smooth metal film is less sensitive to the crystal boundary shape. We show that by controlling the boundary shape, the size and the excitation beam parameters, directional control of propagating plasmonic modes and associated beam parameters such as angular beam splitting, focusing power and beam width can be efficiently achieved. This provides a promising route for robust and alignment-independent integration of plasmonic crystals with optical communication components

Two-dimensional pulse propagation without anomalous dispersion

In two space dimensions and one time dimension a wave changes its shape even in the absence of a dispersive medium. However, this anomalous dispersive behavior in empty two-dimensional space does not occur if the wave dynamics is described by a linear homogeneous wave equation in two space dimensions and {\it two} time dimensions. Wave propagation in such a space can be realized in a three-dimensional anisotropic metamaterial in which one of the space dimensions has a negative permittivity and thus serves as an effective second time dimension. These results lead to a fundamental understanding and new approaches to ultrashort pulse shaping in nanostructures and metamaterials

Non-minimal Wu-Yang wormhole

We discuss exact solutions of three-parameter non-minimal Einstein-Yang-Mills model, which describe the wormholes of a new type. These wormholes are considered to be supported by SU(2)-symmetric Yang-Mills field, non-minimally coupled to gravity, the Wu-Yang ansatz for the gauge field being used. We distinguish between regular solutions, describing traversable non-minimal Wu-Yang wormholes, and black wormholes possessing one or two event horizons. The relation between the asymptotic mass of the regular traversable Wu-Yang wormhole and its throat radius is analysed.Comment: 9 pages, 2 figures, typos corrected, 2 references adde

Пасивна система сонячного теплопостачання

The aim of our study is to calculate the passive solar heat supply of a building with the Trombe-Michel (TM) wall, which is located in Chernivtsi. The investigated building has the following parameters: heating area – 50 m2, heating volume – 150 m3. In the section, the TM wall has a trapezoidal profile with an inclination of the south side, with an area of 8×2.7 m2, to the plane of the horizon 67 ° and orientation to the south. From the south, the TM wall is separated from the outside air by double glazing. The arrival of radiation on the southern surface of the TM wall was determined for the following periods: October-November and March-April. In this case, the absorption coefficient of solar radiation by the surface of the TM wall is assumed to be 0.9. The loss of radiation when passing through the glazing is assumed to be 0.83. The average daily heat losses due to the radiation of the surface of the wall into an infinite space with an ambient temperature are determined. At night, the inner side of the glazing is covered with a shield made from a heat-insulating material to reduce heat loss. Being placed in the basement, a gravel battery accumulates about 2 GJ of heat at a temperature of 75 оС during the summer. The battery is charged by supplying hot air through it, which is heated by solar radiation in the gap between the TM wall and the glazing. In October-November period the air taken by the fan from the room passes through the battery and heated enters the room. This ensures a uniform supply of heat to the premises at a rate of 20 MJ per day for October and 48 MJ per day for November. Heat consumption for heating is determined by dissipative losses due to fencing building constructions and heat consumption during ventilation. The seasonal dependence of the total daily heat input taking into account radiation losses and the use of accumulated heat has been established. The replacement coefficient for heat supply f, as part of solar energy in the total required heat consumption for heating, was determined for different values of heat load γ (from 0.7 to 1.3 W/(m3 hail)) during the autumn and spring months. It has been established that when using the TM wall, replacement rate f of the heat supply of the building considered in Chernivtsi at the volum indicated above, the size of the TM wall and the heat capacity of the battery can be from 25 to 100 % for the autumn and spring months depending on the values of heat load γ.Досліджено розрахунковим способом пасивне сонячне теплопостачання енергоощадного будинку в Чернівцях з розташованою в ньому стіною Тромбе-Мішеля, південна поверхня якої площею 8×2,7 м2 нахилена до площини горизонту під кутом 67 о і відділена від навколишнього середовища подвійним склінням. Будівля є одноповерховим двокімнатним приміщенням з опалювальною площею 50 м2 і опалювальним об'ємом 150 м3. У підвалі будинку розташовано тепловий щебеневий акумулятор, який здатний зберігати до 2 ГДж теплоти за температури 75 оС. Влітку для зарядки акумулятора прогріте в проміжку між стіною Тромбе-Мішеля та склінням повітря відбирається вентилятором, продувається через акумулятор тепла, нагріваючи цим самим його теплоакумулятивну насадку. У жовтні-листопаді забране вентилятором з кімнати повітря проходить через акумулятор і нагріте повертається у приміщення. Встановлено сезонну залежність сумарного добового приходу тепла з урахуванням радіаційних втрат і використанням закумульованого тепла. Наведено розрахунок ефективності пасивної системи сонячного опалення розглянутої будівлі у Чернівцях за вказаних її об'єму, розміру стіни Тромбе-Мішеля і ємності теплового акумулятора, визначено коефіцієнти заміщення, з яких видно, що ступінь підтримки теплопостачання в осінні та весняні місяці може становити, залежно від значень теплового навантаження γ (Вт/(м3∙град)), від 25 до 100 %

РАЗРАБОТКА ЭКСТРАКЦИОННОЙ МЕТОДИКИ ПРОБОПОДГОТОВКИ РАСТИТЕЛЬНЫХ МАСЕЛ ПРИ ОПРЕДЕЛЕНИИ ОСТАТОЧНЫХ КОЛИЧЕСВ ПЕСТИЦИДОВ КЛАССА НЕОНИКОТИНОИДОВ

The distribution of neonicotinoid insecticides (acetamiprid, clothianidin, imidacloprid, thiacloprid, thiamethoxam) in different extraction systems has been studied at 20 ± 1°C. Distribution constants (P) and distribution ratios (D) of pesticides between hexane and the polar phase, rapeseed oil and the polar phase have been calculated. Based on the experimental data, the sample preparation technique has been developed for the determination of neonicotinoid residues in rapeseed, sunflower, linseed and olive oils by high performance liquid chromatography with diode array detection. The extraction method of sample preparation is simple, low reagent and time consuming, and provides chromathograms without analyte peak interference. The recoveries of pesticides from plant matrices are more than 80%. The method allows to determine neonicotinoid insecticides at concentrations below maximum residue levels established in the Republic of Belarus for vegetable oils.При температуре 20 ± 1 °С в различных экстракционных системах изучено распределение инсектицидов класса неоникотиноидов (ацетамиприд, клотианидин, имидаклоприд, тиаклоприд, тиаметоксам). Рассчитаны константы и коэффициенты распределения пестицидов между гексаном и полярной фазой, а также рапсовым маслом и полярной фазой. На основе экспериментальных данных разработана методика определения остаточных количеств неоникотиноидов в рапсовом, подсолнечном, льняном и оливковом маслах методом высокоэффективной жидкостной хроматографии с диодно-матричным детектированием. Экстракционная методика пробоподготовки отличается простотой исполнения, малым расходом реактивов, экспрессностью и обеспечивает получение хроматограмм без пиков, интерферирующих с пиками определяемых веществ. Разработанная методика позволяет определять пестицидыкласса неоникотиноидов на уровне ниже максимально допустимого и характеризуется степенью извлечения определяемых веществ более 80 %

РАЗРАБОТКА И ВАЛИДАЦИЯ МЕТОДИКИ СОВМЕСТНОГО ОПРЕДЕЛЕНИЯ ОСТАТОЧНЫХ КОЛИЧЕСТВ ПЕСТИЦИДОВ В ЗЕРНЕ ОЗИМОЙ ПШЕНИЦЫ МЕТОДОМ ГАЗОВОЙ ХРОМАТОГРАФИИ С МАСС-СПЕКТРОМЕТРИЧЕСКИМ ДЕТЕКТИРОВАНИЕМ

Method for determination of 69 pesticides from different classes (amides, anilinopyrimidines, dinitroanilines, imidazoles, carbamates, carbanilates, morpholines, neonicotinoids, organodithiophosphates, organothiophosphates, pyrethroids, simmtriazines, esters, strobilurins, thiocarbamates, triazoles, etc.) in winter wheat grain by gas chromatography with mass spectrometric detection has been developed and validated by experimental data. The developed extraction method of sample preparation is simple, quick, consumes only cheap and rather common reagents and provides extracts clean enough to obtain reproducible quantitative results without cleaning of injector liner at least for 200 injections. The recovery values of studied pesticides from winter wheat grain were between 76 and 118 % with RSD values below 9 % at 10.0, 20.0 and 200 µg·kg–1 spiking levels. Detection limits were less or equal to 0.01 mg·kg−1 for all the studied pesticides. The obtained limits of quantification were below or equal to the maximum residue levels (MRLs) which are set by Belarus and the European Union for the corresponding pesticides in cereal grains. The linear range used in the calibration curves was from 50 to 3000 µg·L–1 with the values of the determination coefficients R2 more than 0.997. The developed method was successfully used for the analysis of cereal grains for the residues of the pesticides, which were under registration trials held in Belarus in 2015. На основе экспериментальных данных разработана и валидирована методика совместного определения остаточных количеств 69 пестицидов различных классов (амиды, анилинопиримидины, динитроанилины, имидазолы, карбаматы, карбанилаты, морфолины, неоникотиноиды, органодитиофосфаты, органотиофосфаты, пиретроиды, симм- триазины, сложные эфиры, стробилурины, тиокарбаматы, триазолы и др. ) в зерне озимой пшеницы методом газовой хроматографии с масс-спектрометрическим детектированием. Экстракционная методика пробоподготовки отличается простотой исполнения, малым расходом реактивов, экспрессностью и обеспечивает чистоту экстрактов, достаточную для получения воспроизводимых количественных результатов, как минимум, при 200 анализах. Степени извлечения определяемых веществ из зерна озимой пшеницы при уровнях добавок 10,0, 20,0 и 200 мкг·кг–1 составляли 76–118 % при стандартных отклонениях определения не превышающих 9 %. Пределы обнаружения для всех исследованных пестицидов не превосходили 0,01 мг·кг–1. Пределы количественного определения пестицидов не превышали максимально допустимых уровней (МДУ) содержания остаточных количеств пестицидов в зерне хлебных злаков, установленных в Беларуси и Европейском союзе. Площади пиков веществ в диапазоне концентрации от 50 до 3000 мкг·л–1 линейно зависели от их концентрации в растворах. Значения коэффициентов детерминации при этом R2 превышали 0,997. Разработанная методика была успешно использована для анализа зерна зерновых культур на остаточные количества пестицидов, проходивших регистрационные испытания в Беларуси в 2015 году.

Dynamics of infectious and parasitogenic morbidity at the children population in the rural districts and corelation with water factor

Introduction: Intestinal parasites are important enteric pathogens. Poverty, low quality of food and water supply and poor sanitation systems are the important factors associated with intestinal parasitic infections. These kinds of infections can be a good index for hygienic and sanitation status of the society. The aim: To study dynamics of infectious and parasitic diseases (for 2008-2013 years) among the children population in Dnipro region and to define influence of water factor on the disease and prevalence given class of illnesses. Materials and methods: Retrospective study of infectious and parasitogenic diseases (І class by ICD-10) among children population from rural districts of Dnipropetrovsk region for 2008-2013 years was carried out. Results: It was spent correlation analysis between some indicators of potable water quality of diseases of the given class in all districts. In the majority of rural districts, was shown increasing І class of diseases from (1.4 to 1.63) times in dynamics. In some districts was reveled an average correlation link between content in water of the dry residue, chlorides, sulphates, calcium, magnesium, except rigidity and iron and prevalence І class of diseases (r=0.50, p<0.001). Prevalence of the given class of diseases was correlated with рН, nitrates, oxidability in the three rural districts of Dnipropetrovsk region (r=0.74-0.89, p<0.001). Conclusions: It has been shown that the composition of drinking water consumed by the rural population remains one of the basic factors in the formation of public health in the conditions of small exposure of the influence individual indicators of salt and chemical composition. The children’s cohorts were the most sensitive to these indicators