203 research outputs found
A Numerical Implementation of the Soret Effect in Drying Processes
Drying of porous media is strictly governed by heat and mass transfer. However, contrary to the definition that drying is simultaneous transport mechanisms of heat and mass, most past and current models either account for temperature or concentration gradient effects on drying. Even though the complexity of computations of these processes varies with area of application, in most cases, the Dufour and Soret effects are neglected. This leads to deviations and uncertainties on the assumptions and interpretations of these and other relevant effects on drying. This paper covers the theoretical methods to derive the coupled transfer effects. In addition, this work proposes and formulates relevant heat and mass transfer equations, as well as the governing equations for drying processes with Dufour and Soret effects. The application of a numerical approach to solve the equations allows for studying of the influence of these effects on the design and operation of dryers. It is shown that the Soret effect can be highly relevant on drying operations with dynamic heating operation. While for drying processes where the steady state drying process predominates, the effect is deemed negligible
Below ground efficiency of a parasitic wasp for Drosophila suzukii biocontrol in different soil types
The parasitoid wasp Trichopria drosophilae is promising as a biocontrol agent for controlling the ubiquitous pest Drosophila suzukii (Matsumura). Crucial for the successful implementation of any biocontrol agent is a high parasitisation rate by the parasitoid. Most studies investigating the parasitisation rate of D. suzukii pupae have focused on parasitisation in the fruit or in a petri dish. However, the predominant pupation site of D. suzukii in the field is the soil. Unfortunately, little is known on how well parasitoid wasps can detect and parasitise pupae of D. suzukii buried in the soil. Therefore, we conducted soil parasitisation experiments of T. drosophilae on D. suzukii pupae using two pupation depths in three different soil types (loamy sand, loam, and clay). In all three soil types, we found generally low D. suzukii pupae parasitisation rate by T. drosophilae, independent of the pupation depth. The pupation behaviour of D. suzukii and the parasitisation behaviour of T. drosophilae are discussed in detail. For pest control in most soil types, our results mean that the number of D. suzukii larvae pupating in the soil should be reduced, e.g., by adding a layer of sandy soil or covering the soil with plastic mulch. This might increase the probability of success when using T. drosophilae as a biocontrol agent
The preference of Trichopria drosophilae for pupae of Drosophila suzukii is independent of host size
Triangular mass matrices of quarks and Cabibbo-Kobayashi-Maskawa mixing
Every nonsingular fermion mass matrix, by an appropriate unitary
transformation of right-chiral fields, is equivalent to a triangular matrix.
Using the freedom in choosing bases of right-chiral fields in the minimal
standard model, reduction to triangular form reduces the well-known ambiguities
in reconstructing a mass matrix to trivial phase redefinitions. Furthermore,
diagonalization of the quark mass sectors can be shifted to one charge sector
only, without loosing the concise and economic triangular form. The
corresponding effective triangular mass matrix is reconstructed, up to trivial
phases, from the moduli of the CKM matrix elements, and vice versa, in a unique
way. A new formula for the parametrization independent CP-measure in terms of
observables is derived and discussed.Comment: 13 pages, Late
Beziehungen zwischen Chlorosegrad, Eisengehalten und Blattwachstum von Weinreben auf verschiedenen Standorten
Relationship between chlorosis, iron and leaf growth in grapevines growing at different locationsAt different locations, samples from chlorotic and green leaves were taken periodically during the growing season. Leaf area, contents of chlorophyll, total iron and acid-soluble iron were determined in leaf samples from various positions within the shoots. At locations where chlorosis became evident during the growth period, analysis showed that these leaves had lower levels of both total iron and acid-soluble iron compared with leaves of locations without chlorosis. At all locations, a close linear correlation was found between the contents of acid-soluble iron and chlorophyll. For total iron this positive correlation was confined to the lower concentration range (50-90 μg Feig dry weight). The highest and lowest contents of total iron and of acid-soluble iron were found in the youngest leaves and in the leaves with the largest growth rate, respectively. This demonstrates 'dilution' and 'concentration' effects of iron in the leaf dry matter. Therefore, particular care is necessary in leaf sampling as a basis for causal interpretations of iron chlorosis.The results of the present study indicate that the lower uptake and translocation rates of iron rather than the 'inactivation' of iron within the shoots are responsible for chloros is at the various locations
Gauge dependence and renormalization of in the MSSM
Well-known and newly developed renormalization schemes for are
analyzed in view of three desirable properties: gauge independence, process
independence, and numerical stability in perturbation theory. Arguments are
provided that no scheme can meet all three requirements, and as an
illustration, a ``No-Go-Theorem'' for the renormalization of is
established. Nevertheless, two particularly attractive schemes emerge. A
discussion about which scheme might be the best compromise in practice is
given.Comment: 20 pages, improved version that was published in PRD D66 (2002
Mass and Flavor Mixing Schemes of Quarks and Leptons
We give an overview of recent progress in the study of fermion mass and
flavor mixing phenomena. The hints exhibited by the quark and lepton mass
spectra towards possible underlying flavor symmetries, from which realistic
models of mass generation could be built, are emphasized. A variety of schemes
of quark mass matrices at low and superhigh energy scales are described, and
their consequences on flavor mixing and CP violation are discussed. Instructive
patterns of lepton mass matrices, which can naturally lead to large flavor
mixing angles, are explored to interpret current data on atmospheric and solar
neutrino oscillations. We expect that B-meson factories and long-baseline
neutrino experiments will soon shed more light on the dynamics of fermion
masses, flavor mixing and CP violation.Comment: LaTex 81 pages. Minor changes made, typing errors corrected, and
references added. Prog. Part. Nucl. Phys. (in printing
DNA Sensors with Diamond as a Promising Alternative Transducer Material
Bio-electronics is a scientific field coupling the achievements in biology with electronics to obtain higher sensitivity, specificity and speed. Biosensors have played a pivotal role, and many have become established in the clinical and scientific world. They need to be sensitive, specific, fast and cheap. Electrochemical biosensors are most frequently cited in literature, often in the context of DNA sensing and mutation analysis. However, many popular electrochemical transduction materials, such as silicon, are susceptible to hydrolysis, leading to loss of bioreceptor molecules from the surface. Hence, increased attention has been shifted towards diamond, which surpasses silicon on many levels
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