Проектирование системы электроснабжения машиностроительного завода

Объект исследования- электроснабжение машиностроительного завода, подробное рассмотрение цеха твердой изоляции. Цель работы: разработка системы электроснабжения промышленного предприятия. В процессе исследования произведен поэтапный расчет электрических нагрузок завода и рассматриваемого цеха, выбор оборудования и его проверка при различных режимах работы. В результате исследования была спроектирована конкретная модель электроснабжения промышленного предприятия, представлена ее техническая целесообразность и безопасность для окружающей среды. Основные характеристики: исследуемый завод состоит из 16 цехов, относящихся ко 2 категории по степени надежности электроснабжения, напряжение питающей линии 110 кВ; рабочие напряжения внутри завода:0,4 кВ; схема внутризаводской сети– радиальная.Object of research - power supply of engineering plant, detailed consideration of shop of firm isolation. Work purpose: development of the system of power supply of industrial enterprise. In the course of research staged billing of electric loadings of plant and the considered shop, the choice of the equipment and its check in case of various operating modes is made. As a result of research the specific model of power supply of industrial enterprise has been designed, its technical feasibility and safety for environment is provided. Main characteristics: the researched plant consists of 16 shops belonging to the 2nd category on degrees of reliability of power supply, tension of the feeding line of 110 kV; working tension inside zavoda:0,4 kV; the scheme of an intra factory network – radia

Energy end-use flexibility of the next generation of decision-makers in a smart grid setting: an exploratory study

Demand Response (DR) mechanisms have been developed to reshape consumption patterns in face of price signals, enabling to deal with the increasing penetration of intermittent renewable resources and balance electricity demand and supply. Although DR mechanisms have been in place for some time, it is still unclear to what extent end-users are ready, or willing, to embrace DR programs that can be complex and imply adjustments of daily routines. This work aims to understand how the next generation of Portuguese decision makers, namely young adults in higher education, are prepared to deal with energy decisions in the context of the challenges brought by the smart grids. Results demonstrate that cost savings and the contribution to environmental protection are found to be important motivating factors to enroll into DR programs, which should be further exploited in future actions for the promotion of end-user engagement. Moreover, DR solutions are well-accepted by higher education students, although with limited flexibility levels. In addition, there is room to exploit the willingness to adopt time-differentiated tariffs, yet savings should be clearer and more attractive to end-users. Also, the framing effect should be considered when promoting this type of time-differentiated tariffs.This work was partially supported by project grants UID/MULTI/00308/2013 and UID/CEC/00319/2013 and by the European Regional Development Fund through the COMPETE 2020 Programme, FCT—Portuguese Foundation for Science and Technology with in projects ESGRIDS (POCI-01-0145-FEDER-016434), Learn2Behave (02/SAICT/2016-023651), MAnAGER (POCI-01-0145-FEDER-028040), and POCI-01-0145-FEDER-007043, as well as by the Energy for Sustainability Initiative of the University of Coimbra

A shelf-life study of silica- and carbon-based mesoporous materials

Mesoporous silica- and carbon-based materials, including bioactive glasses, have proven potential as components of medical devices and as drug carriers. From an application perspective, knowledge about the shelf-life stability of these materials under various conditions is vital. Here, mesoporous bioactive glasses (MBGs) synthesized by aerosol-assisted spray-drying and by a batch sol–gel method, mesoporous silicas of SBA-15 type, and mesoporous carbons CMK-1 and CMK-3 have been stored under varying conditions, e.g. at different temperature and relative humidity (RH), and in different storage vessels. The results show that the silica-based materials stored in Eppendorfs are sensitive to humidity. Spray dried MBGs decompose within 1 month at a RH >5%, whilst sol–gel MBGs are more stable up to a RH >60%. Changing the storage vessel to sealed glass flasks increases the MBGs lifetime significantly, with no degradation during 2 months of storage at a RH = 75%. SBA-15 stored in Eppendorfs are more stable compared to MBGs, and addition of F- ions added during the synthesis affects the material degradation rate. Mesoporous carbons are stable under all conditions for all time points. This systematic study clearly demonstrates the importance of storage conditions for mesoporous materials which is crucial knowledge for commercialization of these materials

Electrosprayed mesoporous particles for improved aqueous solubility of a poorly water soluble anticancer agent: in vitro and ex vivo evaluation

open access articleEncapsulation of poorly water-soluble drugs into mesoporous materials (e.g. silica) has evolved as a favorable strategy to improve drug solubility and bioavailability. Several techniques (e.g. spray drying, solvent evaporation, microwave irradiation) have been utilized for the encapsulation of active pharmaceutical ingredients (APIs) into inorganic porous matrices. In the present work, a novel chalcone (KAZ3) with anticancer properties was successfully synthesized by Claisen-Schmidt condensation. KAZ3 was loaded into mesoporous (SBA-15 and MCM-41) and non-porous (fumed silica, FS) materials via two techniques; electrohydrodynamic atomization (EHDA) and solvent impregnation. The effect of both loading methods on the physicochemical properties of the particles (e.g. size, charge, entrapment efficiency, crystallinity, dissolution and permeability) was investigated. Results indicated that EHDA technique can load the active in a complete amorphous form within the pores of the silica particles. In contrast, reduced crystallinity (~79%) was obtained for the solvent impregnated formulations. EHDA engineered formulations significantly improved drug dissolution up to 30-fold, compared to the crystalline drug. Ex vivo studies showed EHDA formulations to exhibit higher permeability across rat intestine than their solvent impregnated counterparts. Cytocompatibility studies on Caco-2 cells demonstrated moderate toxicity at high concentrations of the anticancer agent. The findings of the present study clearly show the immense potential of EHDA as a loading technique for mesoporous materials to produce poorly water-soluble API carriers of high payload at ambient conditions. Furthermore, the scale up potential in EHDA technologies indicate a viable route to enhance drug encapsulation and dissolution rate of loaded porous inorganic materials

A reference high-pressure CH₄ adsorption isotherm for zeolite Y: results of an interlaboratory study

This paper reports the results of an international interlaboratory study led by the National Institute of Standards and Technology (NIST) on the measurement of high-pressure surface excess methane adsorption isotherms on NIST Reference Material RM 8850 (Zeolite Y), at 25 °C up to 7.5 MPa. Twenty laboratories participated in the study and contributed over one-hundred adsorption isotherms of methane on Zeolite Y. From these data, an empirical reference equation was determined, along with a 95% uncertainty interval (Uk=2). By requiring participants to replicate a high-pressure reference isotherm for carbon dioxide adsorption on NIST Reference Material RM 8852 (ZSM-5), this interlaboratory study also demonstrated the usefulness of reference isotherms in evaluating the performance of high-pressure adsorption experiments

Outlook and challenges for hydrogen storage in nanoporous materials

Considerable progress has been made recently in the use of nanoporous materials for hydrogen storage. In this article, the current status of the field and future challenges are discussed, ranging from important open fundamental questions, such as the density and volume of the adsorbed phase and its relationship to overall storage capacity, to the development of new functional materials and complete storage system design. With regard to fundamentals, the use of neutron scattering to study adsorbed H2, suitable adsorption isotherm equations, and the accurate computational modelling and simulation of H2 adsorption are discussed. The new materials covered include flexible metal-organic frameworks, core-shell materials, and porous organic cage compounds. The article concludes with a discussion of the experimental investigation of real adsorptive hydrogen storage tanks, the improvement in the thermal conductivity of storage beds, and new storage system concepts and designs.Scopu

The structure of adsorbed CO2 in carbon nanopores: a neutron diffraction study

The behaviour of CO2 adsorbed on a nticroporous carbon at a temperature slightly above the critical point, was studied by adsorption in conjunction with in situ neutron powder diffraction. The carbon sample was produced by carbonisation and activation of a polymer precursor and the experiment was carried out by means of a specially designed adsorption apparatus, directly mounted on the neutron diffractometer. The CO2 diffraction patterns provide evidence that the adsorbed phase is-at pressures well below the critical one-in a state comparable to high-pressure dense supercritical fluid or even bulk liquid. Furthermore, the features of the diffraction patterns are consistent with the presence of orientational correlations between adsorbed molecules. Even though, the scattering data cover a limited Q space and thus the overall resolution is rather poor, the radial distribution functions deduced at different equilibrium pressures, reveal differences, which could be attributed to changes in the arrangement of CO2 molecules along the 308 K isothermal scan. The results are discussed and compared with permeability measurements as well as Monte Carlo calculations. (C) 2004 Elsevier B.V. All rights reserved