Modified One‐at‐a‐time Optimization

An optimization method has been developed that searches one variable at a time under the conditions that previously searched variables are at their approximate optimum and variables to be searched later are constant. This method provides the optimum and also information on the effects of the variables. The method is based on the Partan and Powell methods and on assuming linear partial derivatives of the objective function with respect to any given variable. The procedure involves searching each variable separately with other variables either constant or varied so that they remain at their estimated optimum for the given conditions. This method provides useful information on the effects of independent variables as well as locating the overall optimum and a number of partial optimums and requires a comparable number of trials. Copyright © 1974 American Institute of Chemical Engineer

Mass And Heat Transfer Relations In Evaporation Through Porous Membranes

This study concerns rates of evaporation and mass transfer of water vapor from a heated salt solution through a water repellent porous membrane to a cooled water condensate. This transfer is a result of temperature differences and corresponding vapor pressure differences across the membrane. Three groups of experiments were carried out which indicate that the major factor influencing the rates of transfer is diffusion through a stagnant gas in the membrane pores. However, an equation considering film heat transfer coefficients, membrane thermal conductivity, and an empirical correction based on temperature driving force appears to be necessary for representing all the data. The empirical correction appears to be related to internal condensation and possibly diffusion along surfaces. Copyright © 1969 American Institute of Chemical Engineer

Framework, principles and recommendations for utilising participatory methodologies in the co-creation and evaluation of public health interventions

Background: Due to the chronic disease burden on society, there is a need for preventive public health interventions to stimulate society towards a healthier lifestyle. To deal with the complex variability between individual lifestyles and settings, collaborating with end-users to develop interventions tailored to their unique circumstances has been suggested as a potential way to improve effectiveness and adherence. Co-creation of public health interventions using participatory methodologies has shown promise but lacks a framework to make this process systematic. The aim of this paper was to identify and set key principles and recommendations for systematically applying participatory methodologies to co-create and evaluate public health interventions. Methods: These principles and recommendations were derived using an iterative reflection process, combining key learning from published literature in addition to critical reflection on three case studies conducted by research groups in three European institutions, all of whom have expertise in co-creating public health interventions using different participatory methodologies. Results: Key principles and recommendations for using participatory methodologies in public health intervention co-creation are presented for the stages of: Planning (framing the aim of the study and identifying the appropriate sampling strategy); Conducting (defining the procedure, in addition to manifesting ownership); Evaluating (the process and the effectiveness) and Reporting (providing guidelines to report the findings). Three scaling models are proposed to demonstrate how to scale locally developed interventions to a population level. Conclusions: These recommendations aim to facilitate public health intervention co-creation and evaluation utilising participatory methodologies by ensuring the process is systematic and reproducible

The Mating Type Locus (MAT) and Sexual Reproduction of Cryptococcus heveanensis: Insights into the Evolution of Sex and Sex-Determining Chromosomal Regions in Fungi

Mating in basidiomycetous fungi is often controlled by two unlinked, multiallelic loci encoding homeodomain transcription factors or pheromones/pheromone receptors. In contrast to this tetrapolar organization, Cryptococcus neoformans/Cryptococcus gattii have a bipolar mating system, and a single biallelic locus governs sexual reproduction. The C. neoformans MAT locus is unusually large (>100 kb), contains >20 genes, and enhances virulence. Previous comparative genomic studies provided insights into how this unusual MAT locus might have evolved involving gene acquisitions into two unlinked loci and fusion into one contiguous locus, converting an ancestral tetrapolar system to a bipolar one. Here we tested this model by studying Cryptococcus heveanensis, a sister species to the pathogenic Cryptococcus species complex. An extant sexual cycle was discovered; co-incubating fertile isolates results in the teleomorph (Kwoniella heveanensis) with dikaryotic hyphae, clamp connections, septate basidia, and basidiospores. To characterize the C. heveanensis MAT locus, a fosmid library was screened with C. neoformans/C. gattii MAT genes. Positive fosmids were sequenced and assembled to generate two large probably unlinked MAT gene clusters: one corresponding to the homeodomain locus and the other to the pheromone/receptor locus. Strikingly, two divergent homeodomain genes (SXI1, SXI2) are present, similar to the bE/bW Ustilago maydis paradigm, suggesting one or the other homeodomain gene was recently lost in C. neoformans/C. gattii. Sequencing MAT genes from other C. heveanensis isolates revealed a multiallelic homeodomain locus and at least a biallelic pheromone/receptor locus, similar to known tetrapolar species. Taken together, these studies reveal an extant C. heveanensis sexual cycle, define the structure of its MAT locus consistent with tetrapolar mating, and support the proposed evolutionary model for the bipolar Cryptococcus MAT locus revealing transitions in sexuality concomitant with emergence of a pathogenic clade. These studies provide insight into convergent processes that independently punctuated evolution of sex-determining loci and sex chromosomes in fungi, plants, and animals

Process Energy Evaluations and Optimization in International Projects

A discussion is presented of some of the factors which enter into the economic evaluations and optimizations of energy consuming or producing processes with special emphasis on international projects with multiple national and financial interests involved. In such analyses the objectives and the prices of energy and other factors used have an important effect

Linear process calculations as convergence accelerators in flowsheet-sequenced programs

Linear process calculations were developed for use in conjunction with flow‐sheet‐sequenced calculations, as methods of convergence acceleration. Two such methods were compared with the successive substitution and Wegstein methods on relatively simple processes. Linear Process Simulation, which requires user‐derived equations, produced the best results. Copyright © 1986 American Institute of Chemical Engineer

Studies On The Rate Of Lysine Production By Brevibacterium Lactofermentum From Glucose

The production of lysine by a microbial method was studied using Brevibacterium lactofermentum (ATCC 21086) in shake flasks and a 7.5-liter fermentor. Lysine, residual glucose, cell counts, and dissolved oxygen were measured as a function of fermentation time. The effects of casamino acid, soypeptone, certain amino acids, glucose, and agitation on the rate of production and the yield were investigated. It appeared that reducing any one of the variables caused appreciable decrease in lysine production rates and yields. Plots of rate and d (log lysino)/dt were made to find the relationship between the rate of lysine production and the other factors. Plotting d (log lysine)/dt vs. lysine appears to be the most suitable method of comparing production rates. A mathematical expression was derived which appears to approximately fit the rates of lysine production. © 1976, Applied Microbiology, Molecular and Cellular Biosciences Research Foundation. All rights reserved

Kinetics Of The Pyrolysis Of Utah Tar Sands

Utah tar sands have been pyrolyzed experimentally in a tubular furnace into a stream of nitrogen. Various condensate products have been collected and analyzed, and the pyrolyzed sands have been analyzed for coke and unreacted bitumen. The kinetics of the pyrolysis appeared to be second order under conditions of approximately constant temperature and in experiments with continuously changing temperatures. A lighter product with less sulfur, nitrogen, and arsenic was produced when more rapid heating rates were used. Other characteristics of the reaction and products are presented. Copyright © 1987 Canadian Society for Chemical Engineerin

Air-blown Wood Gasification in a Large Fluidized Bed Reactor

Wood gasification in the Gasification Research on Wood (GROW) pilot plant at the University of Missouri-Rolla has been described. The effects of various types of reactors, feed materials, methods, moisture contents, residence times, and bed temperatures on quality and quantity of product gas were studied. It was found that the car- bon-to-nitrogen ratio was a major factor in this process. Empirical correlations and design methods are presented. The economics for the proposed system were evaluated