Search results for "Civil engineering"

A review of health assessment techniques for distribution transformers in smart distribution grids

2020

Due to the large number of distribution transformers in the distribution grid, the status of distribution transformers plays an important role in ensuring the safe and reliable operation of the these grids. To evaluate the distribution transformer health, many assessment techniques have been studied and developed. These tools will support the transformer operators in predicting the status of the distribution transformer and responding effectively. This paper will review the literature in the area, analyze the latest techniques as well as highlight the advantages and disadvantages of current methodologies.

Prosumer’s impact on low voltage distribution networks

2019

The use of renewable energy, within nowadays energy policy, has increased considerably all over the world in order to respond to the increasing energy consumption and to reduce the environmental impact of the electricity generation. At the beginning, the relatively low penetration levels of distributed generation does not produce problems, however, the nowadays massive increase of local power generation have led to new integration challenges in order to ensure the reliability and quality of the power supply. This paper also highlights some aspects regarding the use of the active distribution networks of low voltage to which electric energy producers are connected-the prosumers: advantages a…

Chemical and biological evaluation of cross-linked halloysite-curcumin derivatives

2020

Abstract Well designed and safe nano drug carrier systems are an important tool in biomedical applications. The combination of two or more drugs has been used in medicine both to enhance the therapeutic effect and to decrease the side effects of drugs. Biocompatible halloysite nanotubes, that possess two different surfaces, are a suitable nanomaterial for a simultaneous carrier and release of two drugs that can exert a synergistic effect against cancer cells. In this study, three curcumin derivatives and doxorubicin were loaded by supramolecular and covalent linkage at the lumen and external surface of the halloysite nanotubes. The obtained multifunctional systems were characterized by seve…

An In Vitro Stereomicroscopic Evaluation of Bioactivity between Neo MTA Plus, Pro Root MTA, BIODENTINE & Glass Ionomer Cement Using Dye Penetrati…

2021

The ideal root end filling material should form a tight seal in the root canal by adhering to the cavity walls. Several materials have been used for root end filling. The present study aims to find out and compare the bioactivity of Neo MTA Plus, Pro Root MTA White, BIODENTINE & glass ionomer cement as root end filling materials using 1% methylene blue as tracer. Materials and methods: 80 extracted human permanent maxillary anterior teeth were used in the study. They were divided into four groups. Specimens were sectioned transversely in the cervical area to separate the crown from the root. The root canal was obturated with gutta percha and zinc oxide eugenol sealers. Thereafter, each …

Отчетъ завѣдывающаго работами о результатахъ его наблюденій при изученіи желѣзныхъ дорогъ Западной Европы съ предложеніемъ возможнаго переустройства …

1903

Содержание: Предисловіе ; Отдѣлъ I-й. Краткий обзоръ Ж. д. узловъ западной Европы : [Берлинъ. Вѣна. Парижъ. Дрезденъ. Франкфуртъ на Майнѣ. Кельнъ. Гамбургъ] ; Отдѣлъ II-й. Выводъ основныхъ положеній ; Отдѣлъ III-й. Обзоръ основныхъ положеній въ каждомъ изъ узловъ западной Европы ; Отдѣлъ IV-й. Возможное примѣнение основныхъ положеній къ Рижскому узлу ; Отдѣлъ V-й. Заключеніе ; Схема относительной зависимости частей Рижскаго ж. д. узла.

Eröffnungsfeier des Passagierverkehrs in Riga vom neuen Bahnhof "Riga-Glawnaja" (Haupt-Bahnhof) über die neue Düna-Eisenbahnbrücke

1914

Teksts paralēli krievu, vācu un latviešu valodā.

Zur Geschichte der öffentlichen Anlagen und Gärten der Stadt Riga

1913

The influence of building interactions on seismic and elastic body waves

2019

We outline some recent research advances on the control of elastic waves in thin and thick plates, that have occurred since the large scale experiment [S. Brûlé, Phys. Rev. Lett. 112, 133901 (2014)] that demonstrated significant interaction of surface seismic waves with holes structuring sedimentary soils at the meter scale. We further investigate the seismic wave trajectories of compressional body waves in soils structured with buildings. A significant substitution of soils by inclusions, acting as foundations, raises the question of the effective dynamic properties of these structured soils. Buildings, in the case of perfect elastic conditions for both soil and buildings, are shown to int…

Life cycle assessment of low temperature asphalt mixtures for road pavement surfaces: A comparative analysis

2018

The increasing fuel consumption demand, the accelerated pressure imposed by the depletion of 5 scarce raw materials and the urgent environmental protection requirements are forcing the change of 6 pavement industry and academia community’s research endeavors towards the development of low 7 emissions road paving technologies able to significantly reduce mixing and compaction temperature as 8 well as the consumption of virgin raw materials. One set of relatively recent technologies in the field of 9 pavement materials that aims at addressing those concerns are the warm mix asphalt (WMA). In fact, 10 they have the potential to allow the reduction of energy consumption and airborne emissions d…

Paradigms on landfill mining: From dump site scavenging to ecosystem services revitalization

2017

For the next century to come, one of the biggest challenges is to provide the mankind with relevant and sufficient resources. Recovery of secondary resources plays a significant role. Industrial processes developed to regain minerals for commodity production in a circular economy become ever more important in the European Union and worldwide. Landfill mining (LFM) constitutes an important technological toolset of processes that regain resources and redistribute them with an accompanying reduction of hazardous influence of environmental contamination and other threats for human health hidden in former dump sites and landfills. This review paper is devoted to LFM problems, historical developm…