Search results for "Civil Engineering"

Macroelement Model for the Progressive-Collapse Analysis of Infilled Frames

2021

A new multistrut macromodel for the analysis of the progressive-collapse response of infilled reinforced concrete (RC) frames is presented in this paper. The model consists of three struts: two outer infinitely rigid and resistant struts and one inner fiber-section strut. The inclination of the struts as well as the stress-strain response are modulated by two parameters that are obtained by means of analytical correlations provided in the paper. The latter link the geometric and mechanical properties of an infilled frame to the geometric configuration and mechanical response of the equivalent strut model. This confers the model the capability to adapt to consider different collapse configur…

The Results of Changing the Current Solution Concept of Universal Motor Gear Reducers with Helical Gears

2021

By analysing and comparing the existing solutions of universal gear reducers with helical gears of the leading manufacturers, it can be noticed the effort to increase the load capacity of the gear reducer within the same axis height. In this way, the manufacturers can offer smaller (cheaper) gear reducers, as well as to simultaneously increase the values of the largest gear ratios. This concept enables the offer of lower-stage (cheaper) gear reducers with higher gear ratios in certain segments of gear ratios. By these efforts, it is reached the maximum, but the further increase is possible only by changing the current concept of universal gear drives. Within this paper, it is given an overv…

Pyrolysed cork-geopolymer composites: A novel and sustainable EMI shielding building material

2019

Abstract In this investigation, and for the first time, pyrolysed sustainable cork was used to produce waste-based geopolymer-cork composites with enhanced electromagnetic interference (EMI) shielding properties. The influence of the pyrolysed cork amount and the geopolymer porosity on the EMI shielding ability of the composites was studied. The maximum total shielding effectiveness (SET) values achieved by these novel building materials (−13.8 to −15.9 dB) are equal to any other reported geopolymer microwave (MW) absorbers over the X-band, despite containing much lower carbon content. In addition, our composites were produced using an industrial waste (biomass fly ash) as raw material and …

Stability Analysis and Stabilization of T-S Fuzzy Delta Operator Systems with Time-Varying Delay via an Input-Output Approach

2013

Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2013/913234 Open Access The stability analysis and stabilization of Takagi-Sugeno (T-S) fuzzy delta operator systems with time-varying delay are investigated via an input-output approach. A model transformation method is employed to approximate the time-varying delay. The original system is transformed into a feedback interconnection form which has a forward subsystem with constant delays and a feedback one with uncertainties. By applying the scaled small gain (SSG) theorem to deal with this new system, and based on a Lyapunov Krasovskii funct…

Intellectual Capital Management Increase in Offshoring

2021

Offshoring is a method for companies from automotive software development industry to have access to a larger pool of talents or to reduce the development costs. In order to have success, the management must be prepared for knowledge transfer process that will be different while compared to training a new employee at the headquarters. Many companies fail when this step is made and instead of reducing the costs, the loss can drag down the business even to the bankruptcy. In this paper, it is presented a solution for a systematic knowhow increase for the new offshore team, applicable to the processes of knowledge transfer. Complex trainings and various methods of solving the orders are not re…

Analysis of the new submarine interconnection system between Italy and Malta: Simulation of transmission network operation

2016

In this paper, some simulations of the interconnected Sicilian and Maltese transmission systems are performed, in order to assess this new system configuration. The HVAC submarine interconnection between Italy and Malta came into operation in 2015 and is part of a European programme for transmission grid interconnection improvement. This new line has been built in order to allow a better management of the power system of both the islands. Firstly, a brief description of the interconnection system is given. Moreover, the transmission systems of Sicily and Malta are depicted and their structures are shown. The simulations are carried out by means of a model of the interconnected system create…

Aluminium-steel plating by press welding

2021

A series of researches related to aluminium-steel plating by press welding are presented in the paper. In this sense, the influence of the roughness of the aluminium and steel test samples was taken into account, but also of the post-welding heat treatment on the characteristics of the joints made. S355 steel specimens and AlMgSi0.7 F27 aluminium specimens were analyzed. The samples were processed and roughness Ra = 2.51-51.09 µm were obtained. Also, after making the joints, a postwelding heat treatment was applied which consisted of a heating at a temperature of 425 °C with a duration of 6.5 hours and a slow cooling to room temperature. Six distinct samples were made in terms of surface ro…

Surveying and Observing Political Elites

2017

Surveys and observation are two strategies of inquiry that gather rich amounts of data about political elites’ opinions, attitudes, and behavior. These research techniques have experienced advances benefitting from the development of the Internet and new technological tools. Survey research has evolved from country studies to comparative research with greater amounts of units and cases. However, such studies face important challenges regarding questionnaire design, sampling, interviewing, and data analysis. In particular, problems of representativity and lack of control may threaten comparative analysis. On their side, observation techniques raise the question of accessibility, of potential…

Pāļu pamati

1938

Būvmechanika

1939

Izdevumu pēc profesora E. Veisa Latvijas Universitatē lasītām lekcijām sastādījis Arnolds Kazaks.