Search results for "forestry"
showing 10 items of 1998 documents
Nature of water-biochar interface interactions
2012
A poplar biochar obtained by an industrial gasification process was saturated with water and analyzed using fast field cycling (FFC) NMR relaxometry in a temperature range between 299 and 353 K. Results revealed that the longitudinal relaxation rate increased with the increment of the temperature. This behavior was consistent with that already observed for paramagnetic inorganic porous media for which two different relaxation mechanisms can be accounted for: outer- and inner-sphere mechanisms. The former is due to water diffusing from the closest approach distance to infinity, whereas the second is due to water interacting by nonconventional H-bonds to the porous surface of the solid materi…
Characterization of micro-fibrillated cellulose fiber suspension flow using multi scale velocity profile measurements
2017
Rheological properties and boundary layer flow behavior of Micro Fibrillated Cellulose (MFC) suspended in water was studied using a novel velocity profiling rheometric technique. The method is based on measuring stationary velocity profiles of fluid flow in a straight tube simultaneously by Doppler Optical Coherence Tomography (DOCT) and by Ultrasound Velocity Profiling (UVP). The high resolution DOCT provides velocity profiles near the transparent tube wall, while UVP yields corresponding information in the interior parts of the flow. The data from the two instruments is combined into a comprehensive velocity profile including both the thin boundary layer near the wall and the interior par…
Drying rate control in microwave assisted processing of sliced apples
2018
The most enhanced microwave systems for the preparation of quality-dehydrated fruits continuously adjust the power level in order to maintain the product temperature above a target value. As a result, typical drying curves that exhibit high drying rates in the middle stage are obtained. This can often lead to quality damage or undesirable changes on food colour and texture. In response to these issues, a microwave system is proposed that can realise drying processes keeping drying rates constant. This approach required a continuous temperature adjustment of the apple slices under test, whose temperature was detected by a computer-aided infrared thermography system. Since temperature correct…
Diode laser reliability in dynamic laser speckle application: Stability and signal to noise ratio
2018
Abstract The biospeckle, or dynamic laser speckle, is used as a potential tool to monitor activity in many biological and non-biological materials from agriculture to medicine, and it is usually based on the use of He-Ne and diode lasers, the latter of which has great potential to be embedded in portable equipment. Some queries about the stability of the diode laser were raised, such as the real influence of the mode hopping phenomenon as a drawback in solid-state devices in comparison to the well-known He-Ne lasers, and thus we decided to test it . In addition, we present an alternative way to enhance the stability and the signal-to-noise ratio of the information using a relative index rat…
Bayesian calibration of the nitrous oxide emission module of an agro-ecosystem model
2008
1. NitroEurope Open Science Conference on Reactive Nitrogen and the European Greenhouse Gas Balance ; Ghent (Belgique) - (2008-02-20 - 2008-02-21) / Conférence; Nitrous oxide (N2O) is the main biogenic greenhouse gas contributing to the global warming potential (GWP) of agro-ecosystems. Evaluating the impact of agriculture on climate therefore requires a capacity to predict N2O emissions in relation to environmental conditions and crop management. Biophysical models simulating the dynamics of carbon and nitrogen in agro-ecosystems have a unique potential to explore these relationships, but are fraught with high uncertainties in their parameters due to their variations over time and space. H…
Evaluation of Suitability of Treated Sewage Sludge for Maize Cultivation
2020
The worlds growing population demands more food and creates more waste. Economically viable and environmentally friendly would be to use sewage sludge for agricultural production. There are several limitations for this use – heavy metal content, pathogenic microorganisms, helminths etc.. The different methods of treatment of sewage sludge helps to overcome this problem. The aim of the study is to find the effects of treated sewage sludge on the growth of maize and changes in soil biological activity. Experiments were carried out with dry sewage sludge preparation (SSP) in the such combinations 1) SSP, 2) SSP+PK, 3) SSP+NPK. Controls- loamy soil without additional fertilizer, soil mixed with…
Células del cuello uterino con atipias que no descartan una lesión de alto grado (ASC-H) con premalignidad
2019
Introducción: la presencia de células escamosas con atipias que no descartan una lesión intraepitelial escamosa de alto grado (ASC-H) es significativa, pues cerca de 50% podrían corresponder a una lesión premaligna del cérvix uterino. Objetivo: describir las alteraciones citomorfológicas más frecuentes en los extendidos citológicos categorizados como células escamosas con atipias que no descartan una lesión intraepitelial escamosa de alto grado (ASC-H), con existencia de lesión clínicamente significativa en el resultado histopatológico. Metodología: estudio retrospectivo en el laboratorio de citología de la Facultad de Farmacia y Bioanálisis, Universidad de Los Andes y Clínica de Prevención…
Ecosystem responses to land abandonment in Western Mediterranean Mountains
2017
Agricultural expansion in the Mediterranean resulted in plant and soil degradation due to the intensive use, climate conditions, and rugged terrain. After abandonment, the recovery of vegetation contributed to improvement in soil quality from a hydrological, pedological and geomorphological point of view. This paper shows three examples of ecosystem evolution in abandoned fields in Valencia, Murcia and Andalucia and the application of different methodological approaches that resulted in similar findings. In Valencia, the main responses were the recovery of vegetation after land abandonment and an increase in organic matter and infiltration capacity of soils. In Murcia, with the exception of…
Aridity index, soil erosion and climate drive no-till ecosystem services trade-off in Mediterranean arable land
2021
Abstract Despite the relevant literature on the advantages of no-till (NT) management, the world area under NT is only 10% of the arable land, probably due to several limiting factors as climate, soil types, farming systems and yield. Soil conservation practices and particularly NT soil management are able to provide many ecosystem services (ESs). This paper suggests a framework to determine the area distribution of soil erosion control and food security ESs trade-offs furnished by NT, starting from the potential soil erosion and aridity index maps. The interaction between the potential soil erosion and the aridity index showed that different trade-offs and synergies of multiple ESs may occ…
Charcoal and stable soil organic matter as indicators of fire frequency, climate and past vegetation in volcanic soils of Mt. Etna, Sicily
2012
Abstract Charcoal fragments in soils are useful to reconstruct past vegetation because the level of preservation is often good enough to determine the tree genus. All forest ecosystems have the potential to burn as a result of naturally occurring or human-induced fires. Forest fires are coupled to climate and are a not-negligible factor of pedogenesis in Mediterranean areas, where they occur frequently. Furthermore, soil organic matter (SOM) is prone to undergo peculiar changes due to forest fires, both in terms of quantity and quality. A soil sequence along an elevational gradient ranging from Mediterranean to subalpine climate zones on slopes of Mt. Etna (Sicily, Italy) was investigated i…