Increasing Stiffness of Constructions through Application of Enhancing Elements

Presented in this work is a study on construction stiffness, based on examination of their neutral lines for various cross-section geometries and different force magnitudes. Investigations were conducted both through numerical simulations and experimentally. The results of numerical simulations indicate that stiffness enhancement reduces deflection in the range of 41-52 %, while the experimental tests showed the reduction of 42-54 %. Also reviewed is comparative analysis between the stiffness results obtained by numerical analyses and experiments, which showed high degree of their compliance. The deviations between the results offered by the two methods are 1-3 %, on average, while in the worst case, which occurs in just a couple of points, the deviation equals 10 %. This study revealed significant increase of element stiffness, which was obtained by employment of additional stiffness enhancing elements

Large Cities and World Economy

Global companies are strongly pressed by the need to simultaneously and equally efficiently manage globally, since the whole world for them is a single market, and locally, due to the fact that the world market makes a number of different and poorly connected markets. The global market today is extremely open and competitive and applicable to the entire world, in the presence of a large number of market operators. The goals and directions of globalization ( and its “conductors” embodied in the powerful multinationals and high-profit industries, such as military, cosmetic, pharmaceutical, etc. ), are increasingly turning to the demolition of the existing state borders and national, customs and trade barriers. And it is, and being an axiom of modern global business

District Energy: Investment Project Appraisal

Publisher Copyright: © 2022, TECNALIA.This chapter presents utility models and project selection criteria for energy and district heating related investments. Utility models are key for attracting investment of different sources for large scale projects. In these cases, guarantees are typically required, which are typically a mixture of stable business environment and liability from public sources. The correct selection of projects requires of a mixture of economic and social criteria, which is typically specific to each site, and is transposed into a set of metrics and performance criteria.Peer reviewe

Influence of oxidation layer generated on preheated contact pairs on static coefficient of friction

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Raman study of the interactions between highly ordered pyrolytic graphite (HOPG) and polyoxometalates: The effects of acid concentration

Heteropoly acids (HPAs) have found wide applications, such as in catalysis, energy conversion and storage, analytical chemistry, clinical medicine, materials science and others, but their use is limited due to their low surface area and high solubility in water. One of the possible ways to overcome these obstacles is to use height specific surface area supports for HPAs, such as carbon nanomaterials. Raman spectroscopy was applied for a studying the interaction between HPAs and highly ordered pyrolytic graphite (HOPG) as a model of a support. HOPG was exposed to two different HPAs: 12-tungsto-phosphoric acid and 12-molybodphosphoric acid, at different concentrations. It was noticed that 12-molybodphosphoric acid had stronger effects on the HOPG structure causing a weak doping and an increase of structural disorder. It was supposed that HOPG interacts with especially external oxygen atoms of 12-molybodphosphoric acid. Atomic force microscopy showed that the surface roughness of HOPG treated with 12-molybodphosphoric acid increases with increasing acid concentration, while in the case of HOPG exposed to 12-tungsto-phosphoric acid, the surface roughness concentration independent. The growth trend in the measured surface roughness (RMS) was in the agreement with the changes in the intensity ratio I-D/I-G obtained from the Raman spectra of the HOPG samples treated with 12-molybdophosphoric acid

Laser-induced surface oxidation of (Ni/Ti)/Si system with picosecond laser pulses

The surface oxidation of Ni/Ti bilayer, deposited on silicon substrate, affected by picosecond Nd: YAG laser radiation has been investigated. Fluence close to the target ablation threshold and multi-pulse laser irradiation regime were applied. Changes in the chemical composition of the formed surface oxide layer were studied by Elastic Recoil Detection Analysis (ERDA) and X-ray photoelectron spectroscopy (XPS). Morphological features analysis, at the oxide surface layer, was monitored, too. Laser modification as-deposited (Ni/Ti)/Si sample with 10 pulses induces a progressed interaction between Ni and Ti layers with the initial surface oxidation and formation of NiTi alloy phase. Progressed intermixing of components was achieved for the irradiation with 50 and more pulses, when all components were quite uniformly distributed to a depth of about 80 nm. An oxide layer was formed at the surface, with the specific combination of the oxide phases depending on the number of accumulated pulses. Changes in the morphological characteristics are reflected in the increase of the mean surface roughness and the generation of a certain number of cavities. These features are decreased with increasing number of pulses, caused by the surface melting and a pronounced mobility of the materials. (C) 2013 Elsevier B.V. All rights reserved

Geoeconomic variations in epidemiology, ventilation management, and outcomes in invasively ventilated intensive care unit patients without acute respiratory distress syndrome: a pooled analysis of four observational studies

Background: Geoeconomic variations in epidemiology, the practice of ventilation, and outcome in invasively ventilated intensive care unit (ICU) patients without acute respiratory distress syndrome (ARDS) remain unexplored. In this analysis we aim to address these gaps using individual patient data of four large observational studies. Methods: In this pooled analysis we harmonised individual patient data from the ERICC, LUNG SAFE, PRoVENT, and PRoVENT-iMiC prospective observational studies, which were conducted from June, 2011, to December, 2018, in 534 ICUs in 54 countries. We used the 2016 World Bank classification to define two geoeconomic regions: middle-income countries (MICs) and high-income countries (HICs). ARDS was defined according to the Berlin criteria. Descriptive statistics were used to compare patients in MICs versus HICs. The primary outcome was the use of low tidal volume ventilation (LTVV) for the first 3 days of mechanical ventilation. Secondary outcomes were key ventilation parameters (tidal volume size, positive end-expiratory pressure, fraction of inspired oxygen, peak pressure, plateau pressure, driving pressure, and respiratory rate), patient characteristics, the risk for and actual development of acute respiratory distress syndrome after the first day of ventilation, duration of ventilation, ICU length of stay, and ICU mortality. Findings: Of the 7608 patients included in the original studies, this analysis included 3852 patients without ARDS, of whom 2345 were from MICs and 1507 were from HICs. Patients in MICs were younger, shorter and with a slightly lower body-mass index, more often had diabetes and active cancer, but less often chronic obstructive pulmonary disease and heart failure than patients from HICs. Sequential organ failure assessment scores were similar in MICs and HICs. Use of LTVV in MICs and HICs was comparable (42·4% vs 44·2%; absolute difference -1·69 [-9·58 to 6·11] p=0·67; data available in 3174 [82%] of 3852 patients). The median applied positive end expiratory pressure was lower in MICs than in HICs (5 [IQR 5-8] vs 6 [5-8] cm H2O; p=0·0011). ICU mortality was higher in MICs than in HICs (30·5% vs 19·9%; p=0·0004; adjusted effect 16·41% [95% CI 9·52-23·52]; p<0·0001) and was inversely associated with gross domestic product (adjusted odds ratio for a US$10 000 increase per capita 0·80 [95% CI 0·75-0·86]; p<0·0001). Interpretation: Despite similar disease severity and ventilation management, ICU mortality in patients without ARDS is higher in MICs than in HICs, with a strong association with country-level economic status