A theoretical model for double diffusive phenomena in cloudy convection

International audienceUsing classical rheological principles, a model is proposed to depict the molecular diffusion in a moist-saturated dissipative atmosphere: due to the saturation condition existing between water vapor and liquid water in the medium, the equations are those of a double diffusive phenomenon with Dufour effect. The double diffusivity is important because of the huge diffusivity difference between the liquid phase and the gaseous phase. Reduced equations are constructed and are then applied to describe the linear free convection of a thin cloudy layer bounded by two free surfaces. The problem is solved with respect to two destabilizing parameters, a Rayleigh number Ra and a moist Rayleigh number Rh . Two instabilities may occur: (i) oscillatory modes, which exist for sufficiently large values of the Rayleigh number: these modes generalize the static instability of the medium; (ii) stationary modes, which mainly occur when the moist Rayleigh number is negative. These modes are due to the molecular diffusion, and exist even when the medium is statically stable: the corresponding motions describe, in the moist-saturated air, configurations such as "fleecy clouds". Growth rates are determined at the instability threshold for the two modes of instability occurring in the process. The case of vanishing moisture concentration is considered: the oscillatory unstable case appears as a singular perturbation (due to the moisture) of the stationary unstable state of the Rayleigh-Bénard convection in pure fluid, and, more generally, as the dynamical perturbation of the static instability. The convective behaviour of a cloud in the air at rest is then examined: the instability of the cloud is mainly due to moisture, while the instability of the surrounding air is mainly due to heating

A survey of land suitable for Townsville stylo in the North Kimberley of W.A. 1973

The aims of the survey were to - (a) define the extent and actual location of country suitable for the production of non-indigenous pastures; in particular to classify the land for its suitability for Townsville stylo (Styioaanthes hurniiia). (b) map the areas so defined on a land system basis. The area surveyed covered approximately 88 000 sq.km (33 968 sq.miles) and included most of the catchments of the Carson, Drysdale, King Edward, Prince Regent, Charnley, Isdell and Chapman Rivers. It covered the country between latitude 14°S and 17°S and longitude 124°30\u27E and 127°30\u27E.https://researchlibrary.agric.wa.gov.au/books/1008/thumbnail.jp

Management and Distribution of Information (MADI) Discussion paper

The Department of Agriculture\u27s mission is To maintain and improve the productivity, profitability and market competitiveness of the rural sector of Western Australia, consistent with conservation of the State\u27s natural resources . To achieve that, the DAWA conducts extensive research, extension, and regulatory programs, and reviews ways it might provide information more effectively and efficiently to its clients, including consultants and farmers Developments in the computing, communication, and education industries are providing opportunities such as video text, free text retrieval, image and document management systems, electronic help lines. bulletin boards, and networks. The situation is continuing to develop rapidly and the DAWA aims to package information in more focused ways and to provide alternative avenues for access On a technical side, the development of common interest networks such as Telecom\u27s Discovery, AARNET, Oz-E-Mail and Pegasus has been rapid. This has allowed the establishment and decentralisation of public bulletin boards providing announcements and current information, and access to database forums with questions and answers. In addition, the technology of in-house CD­ ROM preparation and transferring copious amounts of information to remote locations electronically, or via commercial television networks such as Golden West Network broadcasters, is developing rapidly

Hybrid LTA vehicle controllability as affected by buoyancy ratio

The zero and low speed controllability of heavy lift airships under various wind conditions as affected by the buoyancy ratio are investigated. A series of three hybrid LTA vehicls were examined, each having a dynamic thrust system comprised of four H-34 helicopters, but with buoyant envelopes of different volumes (and hence buoyancies), and with varying percentage of helium inflation and varying useful loads (hence gross weights). Buoyancy ratio, B, was thus examined varying from approximately 0.44 to 1.39. For values of B greater than 1.0, the dynamic thrusters must supply negative thrust (i.e. downward)

Miniature instrument for lab-on-a-chip capillary gel electrophoresis of DNA utilizing temperature control technique

AbstractA complete miniaturized instrument for chip-based capillary gel electrophoresis of DNA with fluorometric detection method and temperature control technique is presented. Separation of single-stranded and double-stranded DNA is obtained in a few minutes utilizing reusable glass chip. Real-time detection is performed using laser-induced-fluorescence and miniature CCD camera. Applied temperature control technique affects mobility of different DNA fragments in polymer sieving matrix. Electrokinetic sample plug injection and separation, temperature stabilization and fluorometric detection are automatically performed in the miniature docking station, controlled by dedicated software with real-time fluorescence signal recognition and digital data conditioning. Presented instrument is automatic, low-cost and portable solution, enabling future application of multitemperature single strand conformation polymorphism (MSSCP) genotyping technique for sensitive detection of minor genetic variants in DNA samples

5-Chloro-1-phenyl-1H-pyrazol-4-amine

In the crystal structure of the title compound, C(9)H(8)ClN(3), amino–pyrazole N—H⋯N hydrogen bonds connect the mol­ecules along the [010] direction; the chains interact with each other only by van der Waals-type inter­actions. The pyrazole and phenyl rings are inclined at a dihedral angle of 45.65 (6)

1-(3-Chlorophenyl)-2-methyl-4-nitro-1H-imidazole-5-carboxamide

In the crystal structure of the title compound, C11H9ClN4O3,pairs of NH N(imidazole) hydrogen bonds connect themolecules into centrosymmetric dimers, which are furtherconnected by NH O(carbamoyl) hydrogen bonds intoC(4) chains along [010]. Interplay of these two kinds ofhydrogen bonds connect the molecules into layers perpendicularto [101]. The imidazole [maximum deviation0.0069 (9) A ] and phenyl rings are inclined at a dihedral angleof 58.44 (6); the nitro group is almost coplanar [dihedralangle 5.8 (2)] with the imidazole ring while the carbamoylgroup is almost perpendicular [70.15 (13)] to it

The infuence of glycosidic linkage neighbors on disaccharide conformation in vacuum

Correct description of the free energy of conformation change of disaccharides is important in understanding a variety of biochemical processes and, ultimately, in the manufacture of better food and paper products. In this study, we determine the relative free energy of a series of 12 disaccharides in vacuum using replica exchange molecular dynamics (repMD) simulations. The chosen sugars and the novel application of this method allow the exploration of the role of glycosidic linkage neighbors in conformer stabilization. In line with expectations, we find that hydrogen bonding (and therefore energetically preferred conformations) are determined both by the nature of the glycosidic linkage (i.e., 1 f 2, 1 f 3, or 1 f 4), the C1 epimer of the of the nonreducing monosaccharide, and by the configuration of carbon atoms once removed from the glycosidic linkage. Contrary to suggestions by prior authors for repMD more generally, we also demonstrate that repMD provides enhanced sampling, relative to conventional MD simulations of equivalent length, for disaccharides in vacuum at 300 K.Fundação para a Ciência e a Tecnologia (FCT)SFRH/BPD/20555/2004/0GVLNational Science Foundation under Grant CHE-043132