Search results for "soil"

Planning of gravimetric investigations on mars

2004

We propose to install a balance at the surface of Mars. In this paper we present a survey on tasks which could be accomplished by means of a balance. The determination of the specific surface area and porosity of Martian soil and other sorption experiments are discussed. Criteria for the choice of a suitable balance type are given.

Soil enzyme assays using p-nitrophenyl derivatives: an inter-laboratory comparison

2011

Reproducibility and reliability of soil enzyme assays need to be validated by comparing results among different labs. The Italian Group of Enzymology organized a ring test among five labs. Beta-glucosidase, acid- and alkaline phosphatase activities were chosen as they are all measurable by using substrates with wide applicability, i.e. p-nitrophenyl derivatives. The five labs preliminarily agreed and standardised the specific methodological procedure for each enzymatic activity, also taking into account factors such as practicability and equipment availability. Nine soils with contrasting physico- chemical and biological properties were adequately sampled, pre-treated and sieved, in order t…

The ability of soil-borne fungi to degrade organophosphonate carbon-to-phosphorus bonds

1997

The ability of a wide variety of soil-borne fungal strains to degrade four structurally different compounds containing P-C bonds, namely the naturally occurring amino acid ciliatine, the popular herbicide glyphosate, phosphonoacetic acid and 2-amino-3-phosphonopropionic acid, was studied in order to show that soil fungi may play an important role in the biodegradation of organophosphonates. Most of the strains appeared to utilize ciliatine as the sole source of phosphorus for growth. Only a limited number of strains were able to grow on the other phosphonates used in this work. The strains of Trichoderma harzianum, Scopulariopsis sp. and Aspergillus niger chosen for more detailed study show…

Photoelectrocatalysis of paracetamol on Pd–ZnO/ N-doped carbon nanofibers electrode

2021

Abstract The presence of pharmaceuticals in water bodies has become a major concern in recent years. An efficient and innovative way of eliminating these pollutants is through photoelectrocatalytic (PEC) degradation owing to its environmental sustainability and its ability to remove recalcitrant pollutants. In this study, palladium loaded zinc oxide/carbon nanofibers (CZnO–Pd) were employed as a novel photoanode for PEC degradation of paracetamol. The CZnO–Pd composite was prepared through electrospinning and atomic layer deposition (ALD). The obtained materials were characterized. Photoelectrochemical studies were carried out with linear sweep voltammetry and chronoamperometry. The removal…

Comparative study on the quality characteristics of some Egyptian mango cultivars used for food processing

2016

This study aims to investigate the physical, chemical, rheological and sensorial properties of six common mango (Mangifera indica) cultivars in Egypt. These common cultivars were Alfonse, Sedeka, Awis, Sinara, Sukari and Zibdia. Weights of mango fruits ranged between 246.6 and 549.2 g. The highest significant value of sphericity was in Alfonse fruits (0.82), whereas the lowest value was 0.58 in Sinara fruits. The highest firmness value was 29.51 N in Sedeka fruits. The highest elasticity was 1.16 N/mm for Sukari fruits. The significantly color intensity chroma was recorded by Sinara, whereas the highest total color index (ΔE) was 88.41 for Sedeka mango cultivar. The significantly lowest pH …

Physicochemical uptake and release of volatile organic compounds by soil in coated-wall flow tube experiments with ambient air

2019

Volatile organic compounds (VOCs) play a key role in atmospheric chemistry. Emission and deposition on soil have been suggested as important sources and sinks of atmospheric trace gases. The exchange characteristics and heterogeneous chemistry of VOCs on soil, however, are not well understood. We used a newly designed differential coated-wall flow tube system to investigate the long-term variability of bidirectional air–soil exchange of 13 VOCs under ambient air conditions of an urban background site in Beijing. Sterilized soil was investigated to address physicochemical processes and heterogeneous/multiphase reactions independently from biological activity. Most VOCs revealed net depositio…

Production altitude and time delays of the terrestrial gamma flashes: Revisiting the Burst and Transient Source Experiment spectra

2008

[1] On the basis of the RHESSI results it has been suggested that terrestrial gamma flashes (TGFs) are produced at very low altitudes. On the other hand some of the Burst and Transient Source Experiment (BATSE) spectra show unabsorbed fluxes of X rays in the 25–50 keV energy range, indicating a higher production altitude. To investigate this, we have developed a Monte Carlo code for X-ray propagation through the atmosphere. The most important features seen in the modeled spectra are (1) a low-energy cutoff which moves to lower energies as TGFs are produced at higher altitudes, (2) a high-energy cutoff which moves to lower energies as TGFs are observed at larger zenith angles, and (3) time d…

Collocated measurements of boundary layer cloud microphysical and radiative properties: A feasibility study

2010

[1] First data from collocated, helicopter-based measurements of boundary layer cloud microphysical properties (effective droplet radius Reff, droplet number concentration N) and spectral radiative quantities (cloud optical thickness τ, cloud top albedo ρ, reflectivity ) are presented. The in situ measurements of the microphysical cloud properties were collected by the Airborne Cloud Turbulence Observation System (ACTOS) attached to a helicopter by a 145 m long rope. Cloud spectral reflectivity was derived from radiances measured by grating spectrometers combined with downward looking optical inlets installed underneath the helicopter. Correlations between cloud microphysics and reflected r…

Reply to comment by R. Grard et al. on “An analysis of VLF electric field spectra measured in Titan's atmosphere by the Huygens probe”

2011

Determination of sea surface temperature at large observation angles using an angular and emissivity-dependent split-window equation

2007

Abstract This paper proposes an angular and emissivity-dependent split-window equation that permits the determination of the sea surface temperature (SST) to a reasonable level of accuracy for any observation angle, including large viewing angles at the image edges of satellite sensors with wide swaths. This is the case of the MODIS radiometer both on EOS Terra/Aqua platforms, with observation angles of up to 65° at the surface, for which the split-window equation has been developed in this study. The algorithm takes into account the angular dependence of both the atmospheric correction (due to the increase of the atmospheric optical path with angle) and the emissivity correction (since sea…