Search results for "content"

Evaluación del efecto rejuvenecedor de bio-materiales sobre ligantes para mezclas con alto contenido de asfalto recuperado

2017

The interest in using bio-materials in pavement engineering has grown significantly over the last decades due to environmental concerns about the use of non-recoverable natural resources. In this paper, bio-materials are used together with Reclaimed Asphalt (RA) to restore some of the properties of the aged bitumen present in mixtures with high RA content. For this purpose, two bio-materials are studied and compared to conventional and polymer modified bitumens. Blends of these materials with RA bitumen were produced and studied to simulate a 50% RA mixture. The rejuvenating effect of the two bio-materials on RA has been assessed and compared with the effect of the conventional binders. App…

Corruption in international business: A review and research agenda

2020

Abstract We systematically reviewed the literature on corruption in international business (137 articles) for the last 17 years between 1992 and 2019. Additionally, we identified seven research streams in this growing literature: (1) the legislation against corruption, (2) the determinants of corruption, (3) combating corruption, 4) the effect of corruption on firms, (5) the political environment and corruption, (6) corruption as a challenge to existing theories of management, and (7) the effect of corruption on foreign direct investment and trade. Based on this review, we recommend that strong international laws are needed to minimize the negative impact of corruption on international busi…

Implementation of Content and Language Integrated Learning at Schools in Latvia

2017

The European Union supports multilingualism and promotes the learning of foreign languages since their knowledge enhances understanding among peoples and increases employability. To increase the efficiency and effectiveness of foreign language education in schools, Content and Language Integrated Learning (CLIL) has been promoted in Europe; this has influenced ways in which Latvia nowadays approaches bilingual education. A qualitative case study was undertaken to explore the implementation of CLIL at schools in Latvia, CLIL being seen as an element of bilingual education. This article outlines the development of CLIL in Latvia, which is largely embedded in national level policies which have…

Binder design of high RAP content hot and warm asphalt mixture wearing courses

2015

Reclaimed Asphalt Pavement (RAP) has shown great potential for being used in the construction or maintenance of roads. However, RAP is usually downgraded to lower pavement layers and the percentage of RAP used in wearing courses is still moderate (≤30%). The research and results contained in this paper focus on the definition of binder recipes aimed at increasing the percentage of RAP in hot and warm mix asphalt wearing courses. A review of current internationally used blend design methodologies is presented followed by case studies aimed at defining binder recipes for high RAP content asphalt mixture wearing courses to be further used for mix design and production in asphalt plants. Binder…

High-content analysis of oxygen reactive species and oxidative stress for toxicology in vitro

2010

Quantifying biogeochemical heterogeneity in soil systems

2018

© 2018 Elsevier B.V. Soils are increasingly perceived as complex systems with properties and biogeochemical functions that vary on millimeter scales. Quantitative information about the resulting biogeochemical heterogeneity is needed to improve process knowledge and to render biogeochemical models more mechanistic. Here we demonstrate how standardized arrays of Pt-electrodes can be used to quantify biogeochemical or ‘functional’ soil heterogeneity, defined as the extent to which the soil is subdivided into microenvironments. Our case study confirmed the validity of this approach for a soil sequence consisting of a well-drained, a moderately well drained and a poorly drained Mollisol. We fou…

HONO Emissions from Soil Bacteria as a Major Source of Atmospheric Reactive Nitrogen

2013

From Soil to Sky Trace gases emitted either through the activity of microbial communities or from abiotic reactions in the soil influence atmospheric chemistry. In laboratory column experiments using several soil types, Oswald et al. (p. 1233 ) showed that soils from arid regions and farmlands can produce substantial quantities of nitric oxide (NO) and nitrous acid (HONO). Ammonia-oxidizing bacteria are the primary source of HONO at comparable levels to NO, thus serving as an important source of reactive nitrogen to the atmosphere.

Plant effects on the soil community: A microcosm experiment

1999

Abstract An experiment was carried out in microcosms for testing the hypothesis that a higher level of primary production should maintain a decomposer community with higher biomass and activity. Microcosms with coniferous forest humus and a diverse microbial and faunal community were divided into three sets: (1) control without plants, (2) with birch seedlings in full illumination, and (3) with birch seedlings, shaded to reduce the net primary production. During 16 weeks of incubation at +16 °C, no treatment effects were found in numbers or biomass of taxonomic or functional groups of soil organisms, nor in the system respiration in darkness. The community structure of the shaded systems di…

Responses of decomposer community to root-isolation and addition of slash

2001

Abstract We studied the causal relationships between forest harvesting and the soil decomposer community focusing on suppression of energy inputs from trees to the soil through root–mycorrhizal network and increased energy input to the soil in the form of slash left on site. We hypothesised that both of these factors would affect the decomposer community, since the soil food web has been regarded as a system in which the amount of resources controls the numbers of consumers. To study the importance of these factors without changes in microclimate, like in sunshine and shade, taking place in clear-felled areas, the experiment was performed in a mature spruce ( Picea abies (L.) Karst.) forest…

Surface soil moisture retrieval using L-band SMAP SAR data and its validation

2016

Surface soil moisture was retrieved globally by systematically correcting for the effects of vegetation and soil surface roughness. The retrieval is enabled by employing physical-models of radar forward scattering for individual vegetation types to account for vegetation scattering and absorption, and by constraining the surface roughness effect using time-series observations. The L-band SMAP multi-polarized (HH/VV/HV) σ° data acquired globally every three days were used from mid-April to early July, 2015. Assessment was conducted over 13 rigorously-chosen core validation sites covering a wide range of biomass types, biomass amount, and soil conditions. The soil moisture retrieval reached a…