Flow field and traverse times for fan forced injection of fumigant via circular or annular inlet into stored grain

Fan forced injection of phosphine gas fumigant into stored grain is a common method to treat infestation by insects. For low injection velocities the transport of fumigant can be modelled as Darcy flow in a porous medium where the gas pressure satisfies Laplace's equation. Using this approach, a closed form series solution is derived for the pressure, velocity and streamlines in a cylindrically stored grain bed with either a circular or annular inlet, from which traverse times are numerically computed. A leading order closed form expression for the traverse time is also obtained and found to be reasonable for inlet configurations close to the central axis of the grain storage. Results are interpreted for the case of a representative 6m high farm wheat store, where the time to advect the phosphine to almost the entire grain bed is found to be approximately one hour.

Mathematical modelling of fumigant transport in stored grain

Computational fluid dynamics, analytical solutions, and mathematical modelling approaches are used to gain insights into the distribution of fumigant gas within farm-scale, grain storage silos. Both fan-forced and tablet fumigation are considered in this work, which develops new models for use by researchers, primary producers and silo manufacturers to assist in the eradication grain storage pests.

The Behaviour of Two-Phase Flow of DNAPL and Water through a Fractured Rock under Confining Pressure

This study presents the characterization of DNAPL and water flow in a fracture under confining pressure. A comprehensive mathematical model and the conditions under which DNAPL will enter an initially water-saturated deforming rock fracture are discussed. A numerical model with which to predict the quantity of each phase in terms of their saturations in deforming rock joint is developed. The effect of varying confining stresses on the traverse time of DNAPL across a fractured aquitard is studied. The sensitivity analysis for physical and hydraulic properties like initial fracture apertures, fracture dips, equivalent fracture aperture and confining pressures are performed and discussed.

Deoxyribonucleic acid replication time in Mycobacterium tuberculosis H37 Rv

The DNA increment method, designed for measuring the increment in the amount of DNA after inhibition of initiation of fresh rounds of replication initiation was employed to measure the rate of deoxyribonucleic acid (DNA) chain growth in Mycobacterium tuberculosis H37Rv growing in Youman and Karlson's medium at 37°C with a generation time of 24 h and also in relatively fast growing species like Mycobacterium smegmatis and Escherichia coli. From the results obtained, the time required for a DNA replication fork to traverse the chromosome from origin to terminus (C period) was calculated. The chain elongation rates of DNA of the three organisms was determined from the C period and the known genome sizes assuming that all these genomes have a single replication origin and bidirectional replication fork. The rate for M. tuberculosis was 3,200 nucleotides per min about 11 times slower than that of M. smegmatis and about 13–18 times slower than that of E. coli.

L’infidélité dans le couple : Charles et Emma Bovary dans Madame Bovary de Flaubert et Dinah et Loulou dans Traversée de la Mangrove de Maryse Condé

Ce travail sur l’infidélité dans le couple traite les différentes sources de l’ennui ainsi que leurs conséquences dans la vie du couple. Les différentes opinions de différents auteurs sur la cause de l’infidélité dans le couple sont vues en long et en large. L’éducation féminine du XIXème siècle éclaire sur le handicap qui a entrainé certaines filles dans le malheur car l’éducation de l’époque ne les avait pas bien préparées pour devenir de bonnes épouses. Ce mémoire montre l’image de la religion dans ces deux oeuvres : Madame Bovary et Traversée de la mangrove. La question est de voir comment ces auteurs peignent la religion dans ces oeuvres et pourquoi ils adoptent l’infidélité pour sauver la femme de son ennui. Enfin, la comparaison de ces ennuis est faite afin de voir que dans ces couples, malgré le fait qu’ils appartiennent à des époques différentes, l’ennui dans le couple est le même. Ces auteurs ont procédé aux mêmes stratégies pour sauver le couple de son ennui. La morale critique et religieuse a été utilisée pour aborder ce thème, lorsque nous avons fait une lecture biblique de ces deux oeuvres.

Tunneling time through a barrier using the local value of a time operator

A time for a quantum particle to traverse a barrier is obtained for stationary states by setting the local value of a time operator equal to a constant. This time operator, called the tempus operator because it is distinct from the time of evolution, is defined as the operator canonically conjugate to the energy operator. The local value of the tempus operator gives a complex time for a particle to traverse a barrier. The method is applied to a particle with a semiclassical wave function, which gives, in the classical limit, the correct classical traversal time. It is also applied to a quantum particle tunneling through a rectangular barrier. The resulting complex tunneling time is compared with complex tunneling times from other methods.