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Open access

Haiwen Mao, Pibo Ma and Gaoming Jiang

Abstract

In this study, woven fabrics with numerous electrostatic charges and desirable charge stability were investigated. A kind of core–shell monofilaments with different melting points between outer and inner layers were applied to wove the fabrics. These fabrics were hot coated through tourmaline particles as an charge enhancer at 122°C. Benefiting from the anions released by tourmaline particles and optimized content of the particles, the fabrics were endowed with surface potentials from −10 to −160 V and the voids content decreased from 45.4% to 41.2%, which contribute to the improvement in the filtration performance of the fabrics. A filtration mechanism was proposed while incremental surface charges with increasing tourmaline particles content have been confirmed through the noncontact measurement of electrostatic charges. The resultant fabrics exhibited a high filtration efficiency of 64.8% and superior long-term service performance. This study can provide a new application of the screen window for PM 2.5 governance.

Open access

Lemnaouar Zedam, Mourad Yettou and Abdelaziz Amroune

Abstract

In a recent paper, Çeven and Öztürk have generalized the notion of derivation on a lattice to f-derivation, where f is a given function of that lattice into itself. Under some conditions, they have characterized the distributive and modular lattices in terms of their isotone f-derivations. In this paper, we investigate the most important properties of isotone f-derivations on a lattice, paying particular attention to the lattice (resp. ideal) structures of isotone f-derivations and the sets of their f-fixed points. As applications, we provide characterizations of distributive lattices and principal ideals of a lattice in terms of principal f-derivations.

Open access

Balázs Bodnár and György Csomós

Abstract

In the EU programming period of 2014–2020, Hungary’s largest-ever transport development project, an intermodal passenger terminal (IPT), is planned to be built in Debrecen. The IPT will integrate all public transport modes operating in Debrecen in a single building, with the modes being as follows: railways, long-distance and local buses, trolley-buses and trams. In addition, by creating a large number of parking spaces for cars, and by building lanes for bicycles and pedestrians heading into the facility, the public transport and individual transport modes will be directly connected under the roof of the IPT. The IPT development will be accompanied by large-scale urban renewal projects to revitalise Petőfi square, one of Debrecen’s major public spaces, lying in front of the building. Relating to the IPT development, several feasibility studies and sustainability analyses have been performed; however, the impact of the IPT on the development of Debrecen has not previously been examined. The main goal of this paper is to examine whether IPT development contributes to the enhancement of Debrecen’s central position in its agglomeration, the strengthening of Debrecen’s competitiveness in Hungary’s urban system, the spatial decentralisation of the city’s cultural activities and how it may influence the change of Debrecen’s socio-economic factors.

Open access

Pavel Vlasák, Zdeněk Chára, Václav Matoušek, Jiří Konfršt and Mikoláš Kesely

Abstract

For the safe and economical design and operation of freight pipelines it is necessary to know slurry flow behaviour in inclined pipe sections, which often form significant part of pipelines transporting solids. Fine-grained settling slurry was investigated on an experimental pipe loop of inner diameter D = 100 mm with the horizontal and inclined pipe sections for pipe slopes ranging from −45° to +45°. The slurry consisted of water and glass beads with a narrow particle size distribution and mean diameter d50 = 180 µm. The effect of pipe inclination, mean transport volumetric concentration, and slurry velocity on flow behaviour, pressure drops, deposition limit velocity, and concentration distribution was studied. The study revealed a stratified flow pattern of the studied slurry in inclined pipe sections. Frictional pressure drops in the ascending pipe were higher than that in the descending pipe, the difference decreased with increasing velocity and inclination. For inclination less than about 25° the effect of pipe inclinations on deposition limit velocity and local concentration distribution was not significant. For descending pipe section with inclinations over −25° no bed deposit was observed.

Open access

Mohammed Sayah Lembarek and Boualem Remini

Abstract

The channel of the Oued Righ valley plays an important role in draining the drainage waters of the palm groves of 47 oases. This article evaluates and offers a simple relationship calculation of flow of drainage water carried by the channel of Oued Righ. Several work missions were carried out in the Oued Righ Valley during the period: 2010–2018. Investigations and surveys were conducted among the local population. Data and information were collected from the National Hydric Resources Agency (Fr. Agence Nationale des Ressources Hydrauliques) of Touggourt (capital of the Oued Righ Valley). Samples of bottom material and flow velocity measurements were performed at 10 gauging stations located along the canal with a length of 130 km. A simple formula for evaluating the flow rate in the channel has been highlighted. It is a practical quantification tool that will be useful for channel managers. Calculated rate exceeded 5 m3∙s−1 of wastewater and drainage flow into the nature 10 km before reaching the Chott Merouane; the place of discharge.

Open access

Pyotr Kovalenko, Anatoliy Rokochinskiy, Jerzy Jeznach, Roman Koptyuk, Pavlo Volk, Nataliіa Prykhodko and Ruslan Tykhenko

Abstract

The analysis of the current state of weather and climatic conditions and evaluation of their predicted changes for immediate and distant prospect in the drained areas of Ukrainian Polissia region was carried out in the article. The main trends in changes of meteorological characteristics and their possible effect on the conditions of functioning water management and ameliorative objects and complexes as well as on the natural and ameliorative state of drained areas were identified. The research uses a method of predictive-simulation modelling with used predictive assessment models of normalized distribution of the basic meteorological characteristics in the long-term and one-year vegetation context. According to the results of the research it was established that, for today a high variability in meteorological characteristics can lead to the significant deterioration of operation conditions of water management and ameliorative objects and units, as well as natural and ameliorative conditions of drained lands in Polissia region as a whole. Core measures regarding the adaptive potential enhancement and development in the region under the conditions of climate change were examined.

Open access

Snežana Vuksanović, Nada Bubanja and Christian Berg

Abstract

During floristic research of acidic bogs, calcareous fens and seasonally flooded (periodically inundated) grassy places in beech forests in Semolj region, Eleocharis carniolica W. D. J. Koch was found, which was the first record of that species in vascular plant flora of Montenegro. In surrounding countries, this species was recorded in Bosnia and Herzegovina, Croatia, Slovenia and Albania. This paper provides description of sites, habitat and ecology of Eleocharis carniolica W. D. J. Koch in Montenegro.

Open access

Magdalena Domańska, Anna Boral, Kamila Hamal, Magdalena Kuśnierz, Janusz Łomotowski and Paulina Płaza-Ożóg

Abstract

The increasingly stringent requirements for wastewater treatment enforce the adoption of technologies that reduce pollution and minimize waste production. By combining the typical activated sludge process with membrane filtration, biological membrane reactors (MBR) offer great technological potential in this respect. The paper presents the principles and effectiveness of using an MBR at the Głogów Małopolski operation. Physicochemical tests of raw and treated wastewater as well as microscopic analyses with the use of the FISH (fluorescence in situ hybridization) method were carried out. Moreover, the level of electric energy consumption during the operation of the wastewater treatment plant and problems related to fouling were also discussed. A wastewater quality analysis confirmed the high efficiency of removing organic impurities (on average 96% in case of BOD5 and 94% in case of COD) and suspension (on average 93%).

Open access

Nihal Kuzu and Ekrem Cicek

Abstract

As radiation science and technology advances, nuclear medicine applications are increasing worldwide which necessitate the understanding of biological implications of such practices. Ionizing radiation has been shown to cause degraded matrix and reduced proteoglycan synthesis in cartilage, and the late consequences of which may include degenerative arthritis or arthropathy. Although degenerative effects of the ionizing radiation on cartilage tissue have been demonstrated, the effects on the mechanical properties of articular cartilage are largely unknown. The radiopharmaceuticals, technetium-99m and technetium-99m sestamibi, were utilized on bovine articular cartilage to investigate these effects. We used two different mechanical tests to determine the mechanical properties of articular cartilage. Dynamic and static mechanical tests were applied to calculate compressive modulus for articular cartilage. We observed clearly higher control modulus values than that of experimental groups which account for lesser stiffness in the exposed cartilage. In conclusion, compressive moduli of bovine articular cartilage were found to decrease after radiopharmaceutical exposure, after both instantaneous and equilibrium mechanical experiments.

Open access

Nargis Sahib

Abstract

Moderate management of temporary wetlands is one of the most proper methods for their restoration and conservation. The cessation of use may lead to high biomass domination by macrophytes as Juncus maritimus (Lam.) that changes plant community structure, threatens species biodiversity, and becomes a danger for their conservation. The experiment was carried out in Sidi Boughaba coastal reserve in Morocco. Two management techniques of wetlands were tested, cutting and uprooting of the rush. Four experimental plots (4.2 × 2.9 m) within the rush belt were set up, with intact plots as a control. Vegetation structure and water levels were monitored on 96 quadrats over two years. The six visits dates, three visits per year (February, April, June), were monitored over two years. The abundance and richness of species were studied, simultaneously with the density of the seed stock in each plot. Results showed that both techniques allowed the opening of the habitat with a significant increase of richness and abundance of species, particularly the restoration of characteristic species of the temporary wetland from the seed bank. The cut technique seems to have less of an effect on the seed stock, total seeds median value was 6.5 in cut plots versus 5 in uprooting plots, being regularly applied given the rapid encroachment of the rush.