Estimability Analysis and Optimisation of Soil Hydraulic Parameters from Field Lysimeter Data

International audienceModelling the water-flow in the vadose zone requires accurate hydraulic parameters to be obtained at the relevant scale.Weighable lysimeters enable us to monitor hydraulic data at an intermediate scale between lab and field scales and they can be used to optimise these parameters. Parameter optimisation using inverse methods may be limited by the nonuniqueness of the solution. In this contribution, an estimability method has been used to assess the estimability of the van Genuchten-Mualem parameters, to evaluate the information content of the data collected from a bare field lysimeter and to optimise the estimable model parameters. Daily data were monitored from a 2 m3 lysimeter, filled with the soil of a former coking plant: pressure heads and water contents were measured at three depths (50, 100, 150 cm), cumulative boundary water fluxes.Water-flow was represented using the onedimensional single-porosity model implemented in HYDRUS-1D code. The estimability ofthe 5 van Genuchten-Mualem hydraulic parameters and the information content of different data were evaluated by sequentially calculating a sensitivity coefficient matrix. Optimisation was achieved by the Levenberg-Marquardt algorithm. The estimability analysis revealed that estimability of the soil hydraulic parameters, based on the combination of daily pressure heads and water contents, was higher than those based on these data separately. In case of 2.4 being considered as a cut-off criterion for this study, all the parameters were considered estimable from daily data in the decreasing order: θs, n, Ks, α, θr . Hydraulic parameters were optimised in four scenarios: θs and n were estimated with reliability while α, Ks and θr were uncertain. However, the narrow variations in measured data restricted parameter optimisation

Demonstration of electronic pattern switching and 10x pattern demagnification in a maskless micro-ion beam reduction lithography system

A proof-of-principle ion projection lithography (IPL) system called Maskless Micro-ion beam Reduction Lithography (MMRL) has been developed and tested at the Lawrence Berkeley National Laboratory (LBNL) for future integrated circuits (ICs) manufacturing and thin film media patterning [1]. This MMRL system is aimed at completely eliminating the first stage of the conventional IPL system [2] that contains the complicated beam optics design in front of the stencil mask and the mask itself. It consists of a multicusp RF plasma generator, a multi-beamlet pattern generator, and an all-electrostatic ion optical column. Results from ion beam exposures on PMMA and Shipley UVII-HS resists using 75 keV H+ are presented in this paper. Proof-of-principle electronic pattern switching together with 10x reduction ion optics (using a pattern generator made of nine 50-{micro}m switchable apertures) has been performed and is reported in this paper. In addition, the fabrication of a micro-fabricated pattern generator [3] on an SOI membrane is also presented

Cultural characteristics and cordycepin production of some Cordyceps militaris strains under artificial cultivation conditions

Cordyceps militaris, a precious medical mushroom, has attracted wide attention in industrial fields. Currently, the degeneration phenomenon of C. militaris commercial strains is amongst the major challenges for cultivation at the industrial scale. The screening for superior strains with high yield and medicinal value is considered a realistic approach to overcome degeneration problems. In the present study, the mycelial growth, primordia formation, yield performance, and cordycepin content of five strains (DT1, DT2, DT3, DT4, and DT5) under artificial cultivation conditions were investigated. All strains showed mycelial growth on SDAY and liquid medium. The strains were successfully cultivated in brown rice medium and required 18 (strain DT3) to 25 days (strain DT5) to form primordia. Additionally, morphological characteristics of fruiting bodies varied among the strains. Strains DT4 and DT3 exhibited the highest fruiting body length with 74.23 ± 5.13 mm and 72.63 ± 2.62 mm, respectively whereas the highest diameter was recorded for strains DT1 (4.05 ± 0.18 mm) and DT2 (3.63 ± 0.12 mm). Of note, among the investigated strains, strain DT3 exhibited the highest biological efficiency (8.95 ± 0.07%) and cordycepin content (1.68 mg/g). Therefore, strain DT3 could be selected as a potential strain for commercial cultivation

Optical properties of Mn-doped ZnS semiconductor nanoclusters synthesized by a hydrothermal process

Undoped and Mn-doped ZnS nanoclusters have been synthesized by a hydrothermal approach. Various samples of the ZnS:Mn with 0.5, 1, 3, 10 and 20 at.% Mn dopant have been prepared and characterized using X-ray diffraction, energy-dispersive analysis of X-ray, high resolution electron microscopy, UV-vis diffusion reflection, photoluminescence (PL) and photoluminescence excitation (PLE) measurements. All the prepared, ZnS nanoclusters possess cubic sphalerite crystal structure with lattice constant a = 5.408 ± 0.011 Á. The PL spectra of Mn-doped ZnS nanoclusters at room temperature exhibit both the 495 nm blue defect-related emission and the 587 nm orange Mn2+ emission. Furthermore, the blue emission is dominant at low temperatures: meanwhile the orange emission is dominant at room temperature. The Mn2+ ion-related PL can be excited both at energies near the band-edge of ZnS host (the UV region) and at energies corresponding to the Mn2+ ion own excited states (the visible region). An energy schema for the Mn-doped ZnS nanoclusters is proposed to interpret the photoluminescence behaviour