Врахування ризиків у процесі взаємодії електронних магазинів та користувачів

Розглядаються ризики, які виникають у відвідувачів електронних магазинів, а також пропонуються можливі заходи безпеки при онлайн-купівлі товарів. Описуються ризики, яким підлягають самі Інтернет-магазини, та наводяться пропозиції щодо підвищення безпеки веб-ресурсу, розміщеного в мереж і Інтернет.Describing the risks arising at visitors of electronic shops are considered, and also possible security' measures are offered at online purchase of the goods. Risks to which Internet shops are exposed are described and offers on improvement of safety of a web resource which Internet is in a network are resulted

Colloidal iron(III) pyrophosphate particles

a b s t r a c t Ferric pyrophosphate is a widely used material in the area of mineral fortification but its synthesis and properties in colloidal form are largely unknown. In this article, we report on the synthesis and characterisation of colloidal iron(III) pyrophosphate particles with potential for application as a food additive in iron-fortified products. We present a convenient and food grade synthetic method yielding stable colloids of nanometre size with a distinctive white colour, a unique characteristic for iron-containing colloids. Physical properties of the colloids were investigated using different techniques, to assess particle crystallinity, surface charge, mass density, refractive index, internal structure, elemental composition and magnetic properties. The findings of this research are especially relevant for food and beverage science and technology and will help develop a more effective use of these fortifiers in colloidal form

Формирование приоритетов интенсификации факторов производства угольного предприятия на основе структурно-иерархического анализа

Проведено оцінку взаємного впливу чинників виробництва і пріоритетів їх формування на базі підприємств вугільної галузі на основі структурно-ієрархічного підходу. Обґрунтовано можливості йі умови аналізу багатоваріантності впливів чинників праці і капіталу на зниження трудомісткості і капіталомісткості очисних робіт. Доведено доцільність застосування методу аналізу ієрархій, за допомогою якого побудовано матриці парних порівнянь. Ключові слова: інтенсифікація чинників виробництва, матриця попарних порівнянь, метод аналізу ієрархій, структурно-ієрархічний метод, чинники виробництва.Проведена оценка взаимного влияния факторов производства и приоритетов их формирования на базе предприятий угольной отрасли на основе структурно-иерархического подхода. Обоснованы возможности и условия анализа многовариантности воздействия факторов труда и капитала на снижение трудоемкости и капиталоемкости очистных работ. Доказана целесообразность применения метода анализа иерархий, с помощью которого построены матрицы парных сравнений. Ключевые слова: интенсификация факторов производства, матрица попарных сравнений, метод анализа иерархий, структурно-иерархический метод, факторы производства.In new economics which is based on the knowledge system the level and complicity of innovation development of industrial complexenterprise is determined by such deep transformational phenomena as change of structure of technological modes in world economy, change of qualitative and quantitative proportions of production factors and, in particular, intensification of production factors, which is able to solve such actual problem as migration to primary intensive way of development. That is why the purpose of this research is development and improvement of methodological approach to formation of priority variants of production factors intensification on the basis of method of hierarchies analysis. For solution ofthis task the method of hierarchies analysis is usedwhich is systematic procedure for hierarchical expressing the elements determining the essence of any problem. The assessment of mutual influence of production factors and priorities of their formation by the example of coal industry enterprise on the basis of structural-hierarchic approach is given in the article. On the basis of structural-hierarchic approach the criteriawere formed, which, each in different ways and with different level of intensity, make influence on meaning of coal enterprise factors. There were proved the possibilities and conditions of multipart influence of labor factors and capital on decrease of labor and capital intensity of coal-face works, which will allow giving rise in increasing effectiveness while securing necessary labor safety. Practicability of method of hierarchies analysis, with the help of which the comparison-of-pairs matrix were built, was proved. Investigation conducted allowed choosing the directions of capital investments for the purpose of getting maximum effect. Keywords: production factors intensification, comparison-of-pairs matrix, method of hierarchies analysis, structural-hierarchic method, production factors

Mesoporous colloidal silica cubes with catalytically active cores

Preparation methods of cubic core-shell particles with specific functionality are limited. Here we demonstrate the possibility to transform cuprous oxide cubes coated with mesoporous silica into functional core-shell particles, while retaining their cubic shape. Cuprous oxide nanocubes are coated with mesoporous silica using cetyltrimethylammonium bromide as a template, after which the cuprous oxide core is transformed using liquid phase calcination and galvanic replacement. Nitrogen physisorption and electron microscopy confirm that mesoporous silica coatings are obtained with tuneable thickness. The successful transformation of cuprous oxide into gold and silver is assessed via UV–VIS spectroscopy and energy dispersive X-ray spectroscopy. Particles with a silver core and a cubic mesoporous silica shell are demonstrated to be catalytically active in the degradation of the dye Congo red. Graphical abstract: [Figure not available: see fulltext.

Становище сільського господарства Чернігівської губернії на початку XX ст.

Chemically responsive hydrogels with embedded magnetic nanoparticles are of interest for biosensors that magnetically detect chemical changes. A crucial point is the irreversible linkage of nanoparticles to the hydrogel network, preventing loss of nanoparticles upon repeated swelling and shrinking of the gel. Here, acrylic acid monomers are adsorbed onto ferrite nanoparticles, which subsequently participate in polymerization during synthesis of poly(acrylic acid)-based hydrogels (PAA). To demonstrate the fixation of the nanoparticles to the polymer, our original approach is to measure low-field AC magnetic susceptibility spectra in the 0.1 Hz to 1 MHz range. In the hydrogel, the magnetization dynamics of small iron oxide nanoparticles are comparable to those of the particles dispersed in a liquid, due to fast Néel relaxation inside the particles; this renders the ferrogel useful for chemical sensing at frequencies of several kHz. However, ferrogels holding thermally blocked iron oxide or cobalt ferrite nanoparticles show significant decrease of the magnetic susceptibility resulting from a frozen magnetic structure. This confirms that the nanoparticles are unable to rotate thermally inside the hydrogel, in agreement with their irreversible fixation to the polymer network

Соматоформная вегетативная дисфункция у лиц молодого возраста в свете современньїх представлений об этиопатогенезе, диагностике и методах восстановительного лечения

Guiding the self-assembly of materials by controlling the shape of the individual particle constituents is a powerful approach to material design. We show that colloidal silica superballs crystallize into canted phases in the presence of depletants. Some of these phases are consistent with the so-called "Λ1" lattice that was recently predicted as the densest packing of superdisks. As the size of the depletant is reduced, however, we observe a transition to a square phase. The differences in these entropically stabilized phases result from an interplay between the size of the depletants and the fine structure of the superball shape. We find qualitative agreement of our experimental results both with a phase diagram computed on the basis of the volume accessible to the depletants and with simulations. By using a mixture of depletants, one of which is thermosensitive, we induce solid-to-solid phase transitions between square and canted structures. The use of depletant size to leverage fine features of the shape of particles in driving their self-assembly demonstrates a general and powerful mechanism for engineering novel materials

Brownian motion: elements of colloid dynamics

This textbook is an introduction to the Brownian motion of colloids and nano-particles, and the diffusion of molecules. One very appealing aspect of Brownian motion, as this book illustrates, is that the subject connects a broad variety of topics, including thermal physics, hydrodynamics, reaction kinetics, fluctuation phenomena, statistical thermodynamics, osmosis and colloid science. The book is based on a set of lecture notes that the authors used for an undergraduate course at the University of Utrecht, Netherland. It aims to provide more than a simplified qualitative description of the subject, without getting bogged down in difficult mathematics. Each chapter contains exercises, ranging from straightforward ones to more involved problems, addressing instances from (thermal motion in) chemistry, physics and life sciences. Exercises also deal with derivations or calculations that are skipped in the main text. The book offers a treatment of Brownian motion on a level appropriate for bachelor/undergraduate students of physics, chemistry, soft matter and the life sciences. PhD students attending courses and doing research in colloid science or soft matter will also benefit from this book