Light scattering in random media with wavelength-scale structures : astronomical and industrial applications

Light scattering, or scattering and absorption of electromagnetic waves, is an important tool in all remote-sensing observations. In astronomy, the light scattered or absorbed by a distant object can be the only source of information. In Solar-system studies, the light-scattering methods are employed when interpreting observations of atmosphereless bodies such as asteroids, atmospheres of planets, and cometary or interplanetary dust. Our Earth is constantly monitored from artificial satellites at different wavelengths. With remote sensing of Earth the light-scattering methods are not the only source of information: there is always the possibility to make in situ measurements. The satellite-based remote sensing is, however, superior in the sense of speed and coverage if only the scattered signal can be reliably interpreted. The optical properties of many industrial products play a key role in their quality. Especially for products such as paint and paper, the ability to obscure the background and to reflect light is of utmost importance. High-grade papers are evaluated based on their brightness, opacity, color, and gloss. In product development, there is a need for computer-based simulation methods that could predict the optical properties and, therefore, could be used in optimizing the quality while reducing the material costs. With paper, for instance, pilot experiments with an actual paper machine can be very time- and resource-consuming. The light-scattering methods presented in this thesis solve rigorously the interaction of light and material with wavelength-scale structures. These methods are computationally demanding, thus the speed and accuracy of the methods play a key role. Different implementations of the discrete-dipole approximation are compared in the thesis and the results provide practical guidelines in choosing a suitable code. In addition, a novel method is presented for the numerical computations of orientation-averaged light-scattering properties of a particle, and the method is compared against existing techniques. Simulation of light scattering for various targets and the possible problems arising from the finite size of the model target are discussed in the thesis. Scattering by single particles and small clusters is considered, as well as scattering in particulate media, and scattering in continuous media with porosity or surface roughness. Various techniques for modeling the scattering media are presented and the results are applied to optimizing the structure of paper. However, the same methods can be applied in light-scattering studies of Solar-system regoliths or cometary dust, or in any remote-sensing problem involving light scattering in random media with wavelength-scale structures.

Emerging bioenergy business at Finnish independent industrial sawmills

Finnish forest industry is in the middle of a radical change. Deepening recession and the falling demand of woodworking industry´s traditional products have forced also sawmilling industry to find new and more fertile solutions to improve their operational preconditions. In recent years, the role of bioenergy production has often been highlighted as a part of sawmills´ business repertoire. Sawmilling produces naturally a lot of by-products (e.g. bark, sawdust, chips) which could be exploited more effectively in energy production, and this would bring more incomes or maybe even create new business opportunities for sawmills. Production of bioenergy is also supported by government´s climate and energy policies favouring renewable energy sources, public financial subsidies, and soaring prices of fossil fuels. Also the decreasing production of domestic pulp and paper industry releases a fair amount of sawmills´ by-products for other uses. However, bioenergy production as a part of sawmills´ by-product utilization has been so far researched very little from a managerial point of view. The purpose of this study was to explore the relative significance of the main bioenergy-related processes, resources and factors at Finnish independent industrial sawmills including partnerships, cooperation, customers relationships and investments, and also the future perspectives of bioenergy business at these sawmills with the help of two resource-based approaches (resource-based view, natural-resource-based view). Data of the study comprised of secondary data (e.g. literature), and primary data which was attracted from interviews directed to sawmill managers (or equivalent persons in charge of decisions regarding bioenergy production at sawmill). While a literature review and the Delphi method with two questionnaires were utilized as the methods of the study. According to the results of the study, the most significant processes related to the value chain of bioenergy business are connected to raw material availability and procurement, and customer relationships management. In addition to raw material and services, the most significant resources included factory and machinery, personnel, collaboration, and geographic location. Long-term cooperation deals were clearly valued as the most significant form of collaboration, and especially in processes connected to raw material procurement. Study results also revealed that factors related to demand, subsidies and prices had highest importance in connection with sawmills´ future bioenergy business. However, majority of the respondents required that certain preconditions connected to the above-mentioned factors should be fulfilled before they will continue their bioenergy-related investments. Generally, the answers showed a wide divergence of opinions among the respondents which may refer to sawmills´ different emphases and expectations concerning bioenergy. In other words, bioenergy is still perceived as a quite novel and risky area of business at Finnish independent industrial sawmills. These results indicate that the massive expansion of bioenergy business at private sawmills in Finland is not a self-evident truth. The blocking barriers seem to be connected mainly to demand of bioenergy and money. Respondents´ answers disseminated a growing dissatisfaction towards the policies of authorities, which don´t treat equally sawmill-based bioenergy compared to other forms of bioenergy. This proposition was boiled down in a sawmill manager´s comment: “There is a lot of bioenergy available, if they just want to make use of it.” It seems that the positive effects of government´s policies favouring the renewables are not taking effect at private sawmills. However, as there anyway seems to be a lot of potential connected to emerging bioenergy business at Finnish independent industrial sawmills, there is also a clear need for more profound future studies over this topic.

Industrial validation of processing maps of 316L stainless steel using hot forging, rolling, and extrusion

The development of microstructure in 316L stainless steel during industrial hot forming operations including press forging (strain rate of 0 . 15 s(-1)), rolling/extrusion (strain rate of 2-8 . 8 s(-1)), and hammer forging (strain rate of 100 s(-1)) at different temperatures in the range 600-1200 degrees C was studied with a view to validating the predictions of the processing map. The results showed that good col relation existed between the regimes indicated in the map and the product microstructures. The 316L stainless steel exhibited unstable flow in the form of flow localisation when hammer forged at temperatures above 900 degrees C, rolled below 1000 degrees C, or press forged below 900 degrees C. All these conditions must therefore be avoided in mechanical processing of the material. Conversely, in order to obtain defect free microstructures, ideally the material should be rolled at temperatures above 1100 degrees C, press forged at temperatures above 1000 degrees C, or hammer forged in the temperature range 600-900 degrees C. (C) 1996 The Institute of Materials.

Diaphragmless shock wave generators for industrial applications of shock waves

The prime focus of this study is to design a 50 mm internal diameter diaphragmless shock tube that can be used in an industrial facility for repeated loading of shock waves. The instantaneous rise in pressure and temperature of a medium can be used in a variety of industrial applications. We designed, fabricated and tested three different shock wave generators of which one system employs a highly elastic rubber membrane and the other systems use a fast acting pneumatic valve instead of conventional metal diaphragms. The valve opening speed is obtained with the help of a high speed camera. For shock generation systems with a pneumatic cylinder, it ranges from 0.325 to 1.15 m/s while it is around 8.3 m/s for the rubber membrane. Experiments are conducted using the three diaphragmless systems and the results obtained are analyzed carefully to obtain a relation between the opening speed of the valve and the amount of gas that is actually utilized in the generation of the shock wave for each system. The rubber membrane is not suitable for industrial applications because it needs to be replaced regularly and cannot withstand high driver pressures. The maximum shock Mach number obtained using the new diaphragmless system that uses the pneumatic valve is 2.125 +/- 0.2%. This system shows much promise for automation in an industrial environment.

Modelling, simulation, and graphical user interface for industrial gas carburising process

A mathematical model has been developed for the gas carburising (diffusion) process using finite volume method. The computer simulation has been carried out for an industrial gas carburising process. The model's predictions are in good agreement with industrial experimental data and with data collected from the literature. A study of various mass transfer and diffusion coefficients has been carried out in order to suggest which correlations should be used for the gas carburising process. The model has been interfaced in a Windows environment using a graphical user interface. In this way, the model is extremely user friendly. The sensitivity analysis of various parameters such as initial carbon concentration in the specimen, carbon potential of the atmosphere, temperature of the process, etc. has been carried out using the model.

Biocorrosion in industrial applications

Industrial situations afflicted by corrosion induced by microorganisms are illustrated with examples. The types and characteristics of microorganisms involved in biocorrosion processes are discussed. Possible mechanisms in biocorrosion as occurring under sub-soil, sea water and fresh water conditions are analyzed. Methods to combat biocorrosion are also outlined.

Study on degradation of H-acid by Alcaligenes latus isolated from textile industrial effluent

This study presents 100% degradation of H-acid under optimized conditions using Alcaligenes latus, isolated from textile industrial effluent. Gene/s responsible for H-acid degradation was/were found to be present on plasmid DNA. Addition of bipyridyl to incubated medium resulted in accumulation of terminal aromatic compound, suggesting that catechol may be terminal aromatic compound in degradation pathway of H-acid by A. latus. SDS-PAGE of cell free extracts showed two prominent bands close to molecular weight of catechol 1,2-dioxygenase.

Combining ``chimie douce'' and green principles for the developing world: Improving industrial viability of photocatalytic water remediation

We highlight the need for a comprehensive, multi-disciplinary approach for the development of cost-effective water remediation methods. Combining ``chimie douce'' and green chemical principles seems essential for making these technologies economically viable and socially relevant (especially in the developing world). A comprehensive approach to water remediation will take into account issues such as nanotoxicity, chemical yield, cost, and ease of deployment in reactors. By considering technological challenges that lie ahead, we will attempt to identify directions that are likely to make photocatalytic water remediation a more global technology than it currently is. (C) 2013 Elsevier Ltd. All rights reserved

Biological sulfate reduction of a sulfate-rich industrial waste liquor using sulfate reducing bacteria

An industrial waste liquor having high sulfate concentrations was subjected to biological treatment using the sulfate-reducing bacteria (SRB) Desulfovibrio desulfuricans. Toxicity levels of different sulfate, cobalt and nickel concentrations toward growth of the SRB with respect to biological sulfate reduction kinetics was initially established. Optimum sulfate concentration to promote SRB growth amounted to 0.8 - 1 g/L. The strain of D. desulfuricans used in this study initially tolerated up to 4 -5 g/L of sulfate or 50 mg/L of cobalt and nickel, while its tolerance could be further enhanced through adaptation by serial subculturing in the presence of increasing concentrations of sulfate, cobalt and nickel. From the waste liquor, more than 70% of sulfate and 95% of cobalt and nickel could be precipitated as sulfides, using a preadapted strain of D. desulfuricans. Probable mechanisms involving biological sulfide precipitation and metal adsorption onto precipitates and bacterial cells are discussed.

Biodiesel Exhaust Treatment with Dielectric Barrier Discharges Coupled with Industrial Waste Byproducts

Biodiesel run engines are gaining popularity since the last few years as a viable alternative to conventional petro-diesel based engines. In biodiesel exhaust the content of volatile organic compounds, oil mist, and mass of particulate matter is considerably lower. However, the concentration of oxides of nitrogen (NOx) is relatively higher. In this paper the biodiesel exhaust from a stationary engine is treated under controlled laboratory conditions for removal of NOx using dielectric barrier discharge plasma in cascade with adsorbents prepared from abundantly available industrial waste byproducts like red mud and copper slag. Results were compared with gamma-alumina, a commercial adsorbent. Two different dielectric barrier discharge (DBD) reactors were tested for their effectiveness under Repetitive pulses /AC energization. NOx removal as high as 80% was achieved with pulse energized reactors when cascaded with red mud as adsorbent.

Incidencia de Cysticercus bovis en la matanza industrial de Nicaragua

En este trabajo, se analizó la situación existente con respecto a la Cysticercosis bovina, en la Empresa Julio Moneada Tercero, ubicada en el Km 11 carretera Norte, departamento de Managua; Esta Empresa cubre el 33% de la matanza industrial en Nicaragua. Con los datos recabados se Evaluaron: Niveles de infestación de los años 1984, 1985, 1988 y 1989; se determinó la infestación por categorías; EL departamento de mayor incidencia; Y las pérdidas económicas. Para el análisis estadístico, el método utilizado fue el de mínimos cuadrados generalizado, usando el procedimiento CATMOD del paquete statistical Analisis System. Los resultados obtenidos en el Análisis de varianza, demuestran que existen diferencias significativas entre años, con un nivel de significancia de P< 0.05 obteniéndose 1.24% de infestación global para los cuatro años, así como también existen diferencias significativas para las diferentes categorías (P< 0.05), siendo la categoría vaca (C2) la más afectada. Matagalpa resultó ser el departamento con el mayor número de animales parasitados seguido de Boaco, Managua y León. Las pérdidas económicas revelan cifras aproximadas de US$ 109,121.50 (ciento nueve mil ciento veinte y un dólares con cincuenta centavos) para el productor, adicionando a esto, las divisas no captadas por un monto aproximado de US$ 653,511.07 (seiscientos cincuenta y tres mil quinientos once dólares con siete centavos) por disminución de las exportaciones.

Residuos de plaguicidas en carne bovina de exportación en el Matadero Industrial Amerrisque

El presente trabajo se realizó en el matadero Amerrisque ubicado a la altura del km 128 carretera el Rama a 130 metros sobre e1 nivel del mar con el objetivo de evaluar los residuos de plaguicidas en carne bovina de exportación. Los datos fueron recopilados de la matanza diaria realizada en dicho matadero a partir del mes de enero de 1987 al mes de diciembre de 1992 a excepción de los meses de marzo, abril, agosto y noviembre del año 1989, de igual forma el año 1990, debido a que los registros ya para este año se encontraron incompletos. Las variables en estudio fueron: Niveles de contaminación aceptable y no aceptable para la exportación, procedencia de dichas carnes, plaguicidas que mayormente se acumulan en 1a carne y las pérdidas económicas. El procedimiento analítico se realizó por medio de una distribución de frecuencias, se hizo uso de medias como estadística descriptiva y también se determinó el rango. Como resultado del presente estudio observamos que la matanza industrial efectuada para los cinco años en estudio fue de 142,919 cabezas, de éstas 18,434 resultaron contaminada con un promedio de contaminación de 0.059 partes por millón, dejándose de percibir USA $ 10,497 dólares.

Efecto de tres periodos de suministro de alimento de retiro en broilers en la Empresa Tip-Top industrial, S.A.

En el presente estudio se evaluaron tres periodos de alimento de retiro o acabado en broilers (o, 3, 6 y 9 días antes de la matanza) el cual contiene 3,225 kcal EM/kg de alimento y 19% de proteína, ajustándose a los requerimientos nutricionales recomendados por Arbor Acres Farm Inc., (1992), en especial a la proporción energia-proteina. La evaluación tuvo lugar en la Granja Buenos Aires propiedad de la Empresa Tip-Top Industrial, S.A., con una duración de 42 días, en donde se utilizaron 800 pollos de engorde sin sexar (mixtos) de la línea Peterson-Arbor Acres de un día de edad, dichos pollos fueron distribuidos aleatoriamente en cuatro tratamientos: T1 suministro de alimento de retiro por nueve días), T2 suministro de alimento de retiro por seis días), T3, (Suministro de alimento de retiro por tres días) y T4 (testigo, con cero días de alimento de retiro), con cuatro repeticiones cada uno, distribuidos en un Diseño completamente al Azar sometidos a la prueba de rangos múltiples de Duncan. Las variables estudiadas fueron: consumo de alimento, peso vivo, ganancia de peso, conversión alimenticia, mortalidad vs viabilidad, rendimiento en la canal, análisis económico. No se encontraron diferencias significativas (P<0.05) entre los tratamientos al final del ensayo para el consumo de alimento, conversión alimenticia y costo de alimento, pero no así ara peso vivo y ganancia de peso. El porcentaje de mortalidad acumulada total fue de 2.5% y los rendimientos de la canal fueron: (90.74)T1 (88.98)T2, (85.86)T3,y (90.31)T4, Se corolo que el periodo de suministro de alimento de retiro que permitió los mejores pesos vivos, ganancias de pesos y conversiones alimenticias fue el periodo de tres días (T3), sin embargo, obtuvo el mayor consumo total para generar un peso promedio en la canal de 3.34 lbs, además, presentó el mayor costo alimenticio entre los tratamientos experimentales (T1, T2, T3) y bajo rendimiento en la canal, contrario al T1 que aunque los parámetros productivos fueron menores que el T3 obtuvo el mayor rendimiento en la canal con un menor costo alimenticio. El alimento de retiro no ejerció efecto sobre las variables estudiadas lo que demuestra que dicho alimento pueda ser una alternativa viable para disminuir costo alimenticio.