Search results for "MINERALOGY"
showing 10 items of 1516 documents
Relationship between radial and concentric cracking of tomato fruit
1983
Abstract A study with 62 genotypes was carried out to establish correlations existing between the percentages of fruits showing concentric cracks of more or less than 2 cm and radial cracks of more or less than 2 cm, considering both early and total production. Over a determined productive period, the susceptibility to form large or small cracks was controlled by the same genetic system (rG = 0.89 – 0.95), yet there was a genetic difference between susceptibility to radial and concentric cracking (rG = 0.53 – 0.68). Genetic systems for susceptibility to radial and concentric cracking seemed to show similarly over the first harvesting and over the total productive period ( r G ⋍ 1 ). Environ…
Correspondence: Strongly-driven Re+CO2 redox reaction at high-pressure and high-temperature.
2016
Correspondence: Strongly-driven Re+CO 2 redox reaction at high-pressure and high-temperature
A simplified falling-head tecnique for rapid determination of field-saturated hydraulic conductivity
2004
Simplified measurements of the field-saturated hydraulic conductivity, K fs , require short duration experiments, small water volumes, and easily transportable equipment. A simplified falling-head (SFH) technique for the rapid determination of K fs has been developed and tested. The technique consists in applying a small volume of water on a soil surface, confined by a ring inserted a short distance into the soil, and then measuring the time from the application of water to the instant at which the surface area is no longer covered by water. A measurement of the initial and field-saturated soil water contents, and an estimate of the α* parameter of the Gardner's exponential model are then u…
Laminated carbonate deposits in Roman aqueducts: Origin, processes and implications
2013
Carbonate deposits in Roman aqueducts of Patara and Aspendos (southern Turkey) were studied to analyse the nature of their regular layering. Optical microscopy and electron-backscattered diffraction results show an alternation of dense, coarsely crystalline, translucent laminae composed of bundles and fans of elongate calcite crystals with their c-axes parallel to the long axis, and porous, fine-grained laminae with crystals at near-random orientation. The ?18O and ?13C data show a strong cyclicity and anti-correlation, whereby high and low ?18O values correspond to dense columnar and porous fine-grained laminae, respectively. Geochemical analyses show similar cyclic changes in carbonate co…
Nucleation and accretion of bioelastomeric fibers at biological temperatures and low concentrations.
1988
Quasi-elastic light scattering (QELS) studies are reported, which address the early stages of aggregation of the polypentamer poly(VPGVG). This reflects the major primary structural feature of native elastin. The study is focused on the region of the phase diagram which in both its temperature and concentration range is closest to the state of affairs occurring in the course of bioelastogenesis by progressive synthesis of the precursor protein. Results here reported allow for the first time a self-consistent view of the physics of elastogenesis, and specify the role of the region of metastability and of that of instability of the phase diagram in the non-chaotic, orderly formation of elasto…
In situ measurement of elastic properties of PdH , PdD , and PdT
2003
Abstract The Young’s modulus E of palladium hydride PdH x , deuteride PdD x and tritide PdT x were measured for studying the effect of both hydrogen stoichiometry x and isotope nature. A special technique based on optical detection of flexural modes of a palladium cylindrical microcantilever was adapted to in situ measurements to guarantee the sample homogeneity during the hydriding process. A 10% decrease in E was found between pure polycrystalline palladium and hydride phases. The non linear dependence observed with the H content was discussed in terms of lattice expansion, phonons and electronic properties. Sensitivity of the technique enables to distinguish an isotope effect on E .
High resolution remote estimation of soil surface water content by a thermal inertia approach
2009
Summary The spatial distribution of soil surface water content in a bare soil was evaluated by a thermal inertia approach from high resolution visible/near infrared (VIS/NIR) and thermal infrared (TIR) airborne data. Given that the relationship between the thermal inertia and the soil water content strongly depends on the accurate estimation of the soil thermal conductivity, two different empirical models were applied to estimate it. Remotely estimated water contents were tested with time domain reflectometry (TDR) measurements collected on a 110 × 90 m 2 bare field in coincidence with airborne over-flights. The thermal conductivity model by Johansen (1975) produced more accurate estimates …
Modelling fractionation of stable isotopes in stalagmites
2009
Abstract High resolution δ13C and δ18O profiles recorded in precisely dated speleothems are widely used proxies for the climate of the past. Both δ13C and δ18O depend on several climate related effects including meteorological processes, processes occurring in the soil zone above the cave and isotope fractionation processes occurring in the solution layer on the stalagmite surface. Here we model the latter using a stalagmite isotope and growth model and determine the relationship between the stable isotope values in speleothem calcite and cave parameters, such as temperature, drip interval, water p CO 2 and a mixing coefficient describing mixing processes between the solution layer and the …
Total CO2output from Vulcano island (Aeolian Islands, Italy)
2012
[1] Total CO2 output from fumaroles, soil gas, bubbling gas discharges and water dissolved gases discharged from the island, was estimated for Vulcano island, Italy. The CO2 emission from fumaroles from the La Fossa summit crater was estimated from the SO2 crater output, while CO2 discharged through diffuse soil emission was quantified on the basis of 730 measurements of CO2 fluxes from the soil of the island, performed by using the accumulation chamber method. The results indicate an overall output of ≅500 t day−1 of CO2 from the island. The main contribution to the total CO2 output comes from the summit area of the La Fossa cone (453 t day−1), with 362 t day−1 from crater fumaroles and 91…
Total (fumarolic + diffuse soil) CO2 output from Furnas volcano
2015
Furnas volcano, in São Miguel island (Azores), being the surface expression of rising hydrothermal steam, is the site of intense carbon dioxide (CO2) release by diffuse degassing and fumaroles. While the diffusive CO2 output has long (since the early 1990s) been characterized by soil CO2 surveys, no information is presently available on the fumarolic CO2 output. Here, we performed (in August 2014) a study in which soil CO2 degassing survey was combined for the first time with the measurement of the fumarolic CO2 flux. The results were achieved by using a GasFinder 2.0 tunable diode laser. Our measurements were performed in two degassing sites at Furnas volcano (Furnas Lake and Furnas Villag…