LOGISTICS SYSTEM IN TOURISM: FEATURES, FUNCTIONS AND OPPORTUNITIES

The article emphasizes the importance of logistics in promoting tourism. The structure of the logistics system and the main functions of the logistics activity in tourism are presented. Opportunities for the introduction and effective use of logistics technologies in tourism are also presented

Proposal for a Listening Comprehension Oriented Classroom -With focus on interpretation practise-

© 2016 American Chemical Society.Interaction of 4,5-dimethyl-2-(2-oxo-1,2-diphenyl)ethoxy-1,3,2-dioxaphospholane, bearing a carboxyl group in the γ-position with respect to the phosphorus atom and obtained from d,l-butanediol, with hexafluoroacetone (CCl4, -40 °C) leads to the simultaneous formation of regio- and stereoisomeric cage-like phosphoranes with phosphorus-carbon and phosphorus-oxygen bonds with a high stereoselectivity (>95%), whose structure was determined by 1D and 2D NMR spectroscopy and XRD. When stored as a solution in dichloromethane for one month, the PCO-isomer rearranges into the thermodynamically more stable POC-isomer of the cage-like phosphorane. Mild hydrolysis of the PCO/POC-isomers proceeds with a high chemoselectivity and leads to the formation of P(IV)-dioxaphospholane derivatives. Acidic hydrolysis of the POC-isomer leads to the formation of an oxirane derivative with an unexpectedly high stereoselectivity (>95%). DFT calculations (using the PBE functional) allowed us to obtain structures and energies of the initial phospholane, reaction products (PCO/POC-isomers), and an intermediate P(V)-oxaphosphirane

Conditional linearizability criteria for a system of third-order ordinary differential equations

We provide linearizability criteria for a class of systems of third-order ordinary differential equations (ODEs) that is cubically semi-linear in the first derivative, by differentiating a system of second-order quadratically semi-linear ODEs and using the original system to replace the second derivative. The procedure developed splits into two cases, those where the coefficients are constant and those where they are variables. Both cases are discussed and examples given

Research of the wastewater treatment method for the production of wood-chip building materials in the presence of nanostructured heterogeneous catalys

ABSTRACT: Introduction. Phenols and petroleum products are common wastewater contaminants in many industries. Due to their persistence and toxicity in the natural environment, an efficient waste disposal technology is needed. Ozonation in the presence of heterogeneous catalysts is one of the advanced methods for treating wastewater from these toxicants. Since most catalysts are expensive, they are being sought on the basis of transition metals and their oxides, which have high activity and relatively low cost. In this regard, the Scientific and Educational Center for Innovative Technologies (SECIT) of USPTU carried out work on the search for an effective and affordable catalyst for the deep oxidation of phenol and petroleum products in wastewater under the influence of ozone. Methods and materials. To study catalytic ozonation, we used model waste water containing phenol and oil products at concentrations of 8 and 30 mg/dm3, respectively. Ozonation was carried out in the presence of fresh (1) and spent (2) NiO–MoO3 catalyst deposited in the form of a film on cylindrical Al2O3 granules weighing 0.5 – 2 g. Results. Optimal conditions of ozonation have been found (1), within 10 min of the decomposition process in its presence, COD decreased by 25% compared to the oxidation process with a catalyst (2), and by 40% compared to classical ozonolysis. It was found that the optimal loading of catalyst (1) is 1 g, duration is 35 min, pH = 8.5, temperature – 22 – 30оC, ozone dose – 5 g/dm3. Discussion. At catalyst dosages of less than 1 g/dm3 , the low efficiency of removing phenol and hydrocarbons is probably due to a lack of the adsorption surface of the catalyst. Conclusion. The studied method of purification allows to reduce the content of phenol and oil products to the standard indicator of drinking water quality (0.001 and 0.05 mg/dm3, respectively), COD by 96% and solve the problem of the harmful effects of these toxicants on ecosystems

Oxyalkylated alcohols phthalates

Polyvinyl chloride (PVC) is used to obtain a wide range of materials for various purposes. High demand of PVC is explained by possibility to modify polyvinyl chloride and produce broad range of materials with improved properties as well as to have cost efficient ratio: productivity, available raw materials, saving of natural resources. However, under normal temperature polyvinyl chloride is brittle and inelastic, that limits the fields of PVC application. The production of basic PVC compositions is impossible without plasticizers – low-molecular compounds that allow direct regulating physical and mechanical properties of polymer. Production of plasticizers became one of the most important branch of petrochemical industry. Recently, however, the range and production of plasticizers have drastically decreased due to the increased cost, which reduced the competitiveness of plasticized PVC products. Therefore, the expansion of plasticizer variety for PVC is a strategic task of great practical significance. The present work describes synthesis methods of esters on the basis of oxyalkylated alcohols suggested as polyvinyl chloride plasticizers. Physico-chemical properties of synthesized compounds were studied. Conditions for their production with maximum outcome were selected. The results of experiments in which obtained compounds were tested as additives in the plasticization of PVC showed that the obtained samples of cable plastic, adhesive PVC tapes and multi-layered polyvinyl chloride linoleum satisfy all the technical requirements by the main indicators: cable plastic compound – GOST 5960-72 with amendment 1-9; a PVC adhesive tape – Technical Conditions – 2245-001-00203312-2003; multilayered linoleum – GOST 7251-77. According to the experimental results, phthalates of oxyalkylated alcohols possess rather high efficiency as plasticizers of polyvinyl chloride and are recommended for use in the above-mentioned industrial PVC recipe

Use of Complex Lie Symmetries for Linearization of Systems of Differential Equations - II: Partial Differential Equations

The linearization of complex ordinary differential equations is studied by extending Lie's criteria for linearizability to complex functions of complex variables. It is shown that the linearization of complex ordinary differential equations implies the linearizability of systems of partial differential equations corresponding to those complex ordinary differential equations. The invertible complex transformations can be used to obtain invertible real transformations that map a system of nonlinear partial differential equations into a system of linear partial differential equation. Explicit invariant criteria are given that provide procedures for writing down the solutions of the linearized equations. A few non-trivial examples are mentioned.Comment: This paper along with its first part ODE-I were combined in a single research paper "Linearizability criteria for systems of two second-order differential equations by complex methods" which has been published in Nonlinear Dynamics. Due to citations of both parts I and II these are not replaced with the above published articl

Protease Activated Receptor Signaling Is Required for African Trypanosome Traversal of Human Brain Microvascular Endothelial Cells

Human African trypanosomiasis, or sleeping sickness, occurs when single-cell trypanosome protozoan parasites spread from the blood to brain over the blood-brain barrier (BBB). This barrier is composed of brain microvascular endothelial cells (BMECs) especially designed to keep pathogens out. Safe drugs for treating sleeping sickness are lacking and alternative treatments are urgently required. Using our human BMEC BBB model, we previously found that a parasite protease, brucipain, induced calcium activation signals that allowed this barrier to open up to parasite crossing. Because human BMECs express protease-activated receptors (PARs) that trigger calcium signals in BMECs, we hypothesized a functional link between parasite brucipain and BMEC PARs. Utilizing RNA interference to block the production of one type of PAR called PAR-2, we hindered the ability of trypanosomes to both open up and cross human BMECs. Using gene-profiling methods to interrogate candidate BMEC pathways specifically triggered by brucipain, several pathways that potentially link brain inflammatory processes were identified, a finding congruent with the known role of PAR-2 as a mediator of inflammation. Overall, our data support a role for brucipain and BMEC PARs in trypanosome BBB transmigration, and as potential triggers for brain inflammation associated with the disease

Principles of Projecting Preschool Education Institutions

 This article describes the principles of projecting of preschool facilities, sanatorium-type kindergartens in the village, the scope of services for kindergartens located in rural areas, the development of plans (analytical schemes) depending on their typ