Doctor of Philosophy / Department of Animal Sciences and Industry / R. Scott Beyer / Broiler chicken feed is processed. Cereal grains are ground to reduce particle size and the feed usually is pelleted. When pelleted, broiler diets are steam conditioned and forced through a die causing varying levels of starch gelatinization. Cereal grain particle size and starch gelatinization can be controlled during feed manufacturing. Earlier research has shown that starch gelatinization negatively affects growth performance of 0 to 21 d of age. An experiment was conducted to determine the effects of corn particle size and starch gelatinization on growth performance, dressing percentage, and gizzard size when fed to 22 to 42 d of age broilers. Increasing particle size from 470 to 1240 μm increased body weight gain, dressing percentage, and relative gizzard size. Starch gelatinization increased relative gizzard size. No interaction effects were detected. To expand on previous experiments, a trial was conducted to investigate the effect of starch gelatinization on broiler chick gastrointestinal pH, glucose absorption, and glucoregulation. Starch gelatinization level affected jejunum pH, with a higher pH reported at 20% starch gelatinization. Increases in starch gelatinization decreased blood glucose and increased glucagon level. Highest measured glucagon level was reported in broiler chicks fed the diet with 20% starch gelatinization level diet after 6 hours of starvation. A third experiment was conducted to determine the effect of starch gelatinization on metabolizable energy and amino acid digestibility. Increasing starch gelatinization from 0 to 100% increased true metabolizable energy and fecal output in roosters. No effect was found on apparent metabolizable energy or amino acid digestibility, with an increase in starch gelatinization from 0 to 20%. Increasing particle size from 470 to 1240 μm had a positive effect on 22 to 42 d growth performance. A starch gelatinization level of 20% or lower had no effect on metabolizable energy or amino acid digestion. Older broilers with larger gastrointestinal tracts are unaffected by 20% gelatinized starch; whereas, 20% gelatinized starch reduced blood glucose and increased glucagon levels of young broilers. Lower blood glucose and increased glucagon are indicative of lower glucose storage, and could cause reduced young broiler growth performance when fed diets with gelatinized starch.

ABSTRACT This work applies the concepts of the attainable region for process synthesis in comminution. The attainable region analysis has been successfully applied for process synthesis of reactor networks. The Attainable Region is defined as the set of all possible output states for a constrained or unconstrained system of fundamental processes (Horn, 1964). A basic procedure for constructing the attainable region for the fundamental processes of reaction and mixing has been postulated in reaction engineering (Glasser et al., 1987). This procedure has been followed in this work to construct the candidate attainable region for size reduction processes as found in a size reduction environment. A population balance model has been used to characterise the evolution of particle size distributions from a comminution event. Herbst and Fuerstenau (1973) postulated the dependency of grinding on the specific energy. A specific energy dependent population balance model was used for the theoretical simulations and for the fitting of experimental data. A new method of presenting particle size distributions as points in the Euclidian space was postulated in place of the traditional cumulative distribution. This allows successive product particle size distributions to be connected forming a trajectory over which the objective function can be evaluated. The curve connects products from successive batch grinding stages forming a pseudo-continuous process. Breakage, mixing and classification were identified as the fundamental processes of interest for comminution. Agglomeration was not considered in any of the examples. Mathematical models were used to describe each fundamental process, i.e. breakage, mixing and classification, and an The application of the attainable region analysis in comminution Abstract algorithm developed that could calculate the evolution of product particle size distributions. A convex candidate attainable region was found from which process synthesis and optimisation solutions could be drawn in two dimensional Euclidian space. As required from Attainable Region Theory, the interior of the bounded region is filled by trajectories of higher energy requirements or mixing between two boundary optimal points. Experimental validation of the proposed application of the attainable region analysis results in comminution was performed. Mono-sized feed particles were broken in a laboratory ball mill and the products were successfully fitted using a population balance model. It was shown that the breakage process trajectories were convex and they follow first order grinding kinetics at long grind times. The candidate attainable region was determined for an objective function to maximise the mass fraction in the median size class 2. It was proved that the same specific energy input produces identical products. The kinematic and loading conditions are supposed to be chosen as a subsequent event after the required specific energy is identified. Finally the fundamental process of classification was added to the system of breakage and mixing. The attainable regions analysis affords the opportunity to quantify exactly the reduction in energy consumption due to classification in a comminution circuit, thus giving optimal targets. Classification showed the potential to extend the candidate attainable region for a fixed specific energy input. The boundary of the attainable region is interpreted as pieces of equipment and optimum process conditions. This solves both the original process synthesis and successive optimisation problems.

A indústria cerâmica tem destinado produtos para as mais diversas áreas e, com a crescente exigência de alta qualidade, tornou-se necessário desenvolver novas técnicas para o processamento cerâmico. O objetivo consiste em produzir corpos a verde (antes da queima) mais homogêneos, com menor incidência de micro-defeitos. Tais materiais podem ser produzidos preparando-se suspensões aquosas de pós cerâmicos como o óxido de alumínio (Al2O3), conhecido como alumina. Estas suspensões possuem um alto teor de sólidos no meio. A adição de outras espécies ao meio auxilia a dispersão das partículas, aumentando a estabilidade da suspensão. Estas espécies podem ser polieletrólitos (polímeros com cargas) que interagem com a superfície das partículas de alumina, através de vários mecanismos, promovendo um impedimento à aproximação de outras partículas. Neste trabalho, foram utilizados três tipos de taninos, que são macromoléculas de origem vegetal, de nome comercial Weibull e Macrospec; e Dispersan, sendo que a diferença entre eles está na quantidade de grupos hidroxila, maior em Macrospec com relação a Weibull, e na mistura com polímero sintético, o poliacrilato de sódio, caso do Dispersan. Um derivado quaternizado de quitosana, (nitrogênio trimetilado), um polissacarídeo natural, também foi utilizado como agente de estabilização. A meta pretendida correspondia à obtenção de suspensões com partículas menores e portanto menor viscosidade e maior fluidez, ou seja a suspensões mais homogêneas que levem a produtos de melhor qualidade. A avaliação da estabilidade das suspensões, devido à adição das macromoléculas, foi feita através de medidas de viscosidade, potencial zeta, diâmetro médio de partícula, além de testes de sedimentação. Dentre os agentes de estabilização utilizados, os taninos Weibull, Macrospec e Dispersan, no geral, apresentaram desempenho similar, contribuindo para uma diminuição da viscosidade e do tamanho das partículas da suspensão e no teste de sedimentação, um melhor empacotamento. A quitosana quaternizada também levou à estabilização da suspensão em determinadas condições mas, comparativamente aos taninos, apresentou desempenho inferior. Os resultados foram promissores, todavia, devendo o estudo ser aprofundado considerando-se condições diversificadas. / The ceramic industry provides products for several areas, and new processing techniques became necessary to meet the quality requirements. The objective is to produce more homogeneous green microstructures (bodies before burning), with lower number of micro-defects. Such materials can be produced from aqueous suspensions of aluminum oxide (Al2O3), known as alumina. These suspensions have a large number of solid particles, and dispersion of particles may be assisted by the addition of other species, increasing stability. These species can be polyelectrolytes (polymers with charges) that interact with the surface of alumina particles, hindering the approach of other particles. In this work, vegetal macromolecules such as tannins and chitosan, polysaccharides found in exoskeleton of crustaceans, are used as stabilizing (stabilization) agents of the suspension. Evaluation of the suspension stability, due to addition of these macromolecules, is performed through measurements of viscosity, zeta potential, particle diameter, pore size and sedimentation tests. The overall aim is the attainment of less viscous suspensions with smaller particles and greater fluidity, i.e. more homogeneous suspensions that lead to better-quality products. Amongst the stabilizing agents used, the tannins presented the better performance, contributing for a reduction in viscosity and particle size, in addition to a better wrapping up in the sedimentation tests. Although the quaternized chitosan has also contributed for a decrease in viscosity and particle size, it presented inferior performance, in comparison to that of tannins. These results were nevertheless promising, and a further study with chitosan is recommended, in which other conditions are employed.

Os fatores envolvidos na obstrução dos gotejadores são divididos em químicos, físicos e biológicos, os quais, dependem da qualidade da água utilizada na irrigação e dos adubos utilizados em fertirrigação. Dentre os fatores físicos estão as partículas de areia, que são classificadas como sólidas inertes, pois não sofrem agregação com outras partículas já presentes na água e nem dispersão. O objetivo deste trabalho foi avaliar a influência do tamanho e concentração de partículas de areia e da velocidade de escoamento da água nas linhas laterais na obstrução de um único modelo de gotejador do tipo cilíndrico, não regulado, com vazão nominal de 2 L h-1. Foram realizados ensaios de obstrução com areia misturada em água destilada, combinando os seguintes fatores: três faixas granulométricas de partículas de areia (53-105; 105-250 e 250-500 μm), três concentrações de areia na água destilada (100, 250 e 500 mg L-1) e três velocidades de escoamento da água no início das linhas laterais (0,13; 0,25 e 0,94 m s-1). O tempo de ensaio para cada combinação de fatores foi de 48 horas. A vazão de 32 gotejadores foi medida a cada doze minutos por meio de um sistema automatizado desenvolvido durante esta pesquisa, sendo que esse operou adequadamente durante todo o período de ensaios de obstrução. Utilizaram-se oito linhas laterais conectadas em linha de derivação com bifurcações simétricas, cuja finalidade era distribuir uniformemente a água as partículas de areia entre as linhas laterais. Em ensaios com faixa granulométrica de 105 a 250 μm, ocorreu a obstrução nas concentrações de 250 e 500 mg L-1, para as velocidades de escoamento da água no inicío das linhas laterais V2 (0,25 m s-1) e V3 (0,94 m s-1). Já na faixa granulométrica de 250 a 500 μm, ocorreu obstrução nas concentrações de 100, 250 e 500 mg L-1, para V2 e V3. A obstrução de gotejadores ocorreu de forma aleatória nas oito linhas laterais. Após obstruídos os gotejadores não desobstruíram com o passar do tempo de ensaio, portanto fenômenos de autolimpeza não foram observados durante os experimentos. / Clogging of emitters is influenced by chemical, physical and biological agents that are associated with irrigation water quality and fertilizers, in case of adoption of fertigation practices. Among the physical agents, sand particles are one of the most important clogging sources. Sand particles are considered to be inert since it does not aggregate with other particles suspended in water. The purpose of this research was to assess influence of concentration, size of sand particles, and flow velocity within laterals on sensitivity of drippers to clogging. The results are limited to a cylindrical integrated dripper of 2 L h-1 nominal flow rate that is a nonpressure compensating emitter. Experiments were undertaken using distilled water and sand particles. The following levels were evaluated: (a) three ranges of particles sizes (0.053-0.105; 0.105-0.25 and 0.25-0.5 mm); (b) three concentrations of particles (100, 250 and 500 mg L-1); and, (c) three flow velocities at the laterals inlet (0.13, 0.25 and 0.94 m s-1). Each testing level had 48 hours duration. The flow rate of 32 drippers was measured every 12 minutes by an automated system developed and successfully validated during this research. A manifold with symmetrical bifurcations was designed to assure uniform water distribution among eight parallel laterals installed on the testing bench. Within the range of particle sizes from 105 to 250 μm, clogging of emitters was observed under concentration of particles of 250 and 500 mg L-1 and under flow velocities of 0.25 and 0.94 m s-1. Within the range of particles sizes from 250 to 500 μm, clogging was observed under all concentrations and under flow velocities of 0.25 and 0.94 m s-1. Apparently, clogging of emitters of the eight laterals occurred randomly. Once clogged, emitters did not recovered its initial flow rate, therefore self-cleaning phenomena was not observed during the experiments.

No Brasil pouco se estuda sobre as estratégias de amostragem em áreas com mais de um tipo de solo e várias feições de paisagem, estratégias estas, importantes para mapear a variabilidade espacial dos atributos físicos: frações granulométricas, como também a correlação destas com os parâmetros geomorfológicos: altitude e inclinação máxima da área amostrada da extensão multivariada da krigagem, a cokrigagem. Essa extensão multivariada permite a associação de duas variáveis dependentes gerarem novas informações correlacionadas através do modelo de variância cruzada. O objetivo deste trabalho foi avaliar a correlação espacial entre a distribuição da fração granulométrica com os parâmetros de altitude e a inclinação máxima através de uma densidade amostral agregada (100x100 e 50x50m) com dois níveis de densidade amostral, 20x20 e 40x40m. O estudo se deu numa área de 180 ha, onde se coletou frações de solo numa grade amostral agregada, ou seja, um arranjo amostral 100x100m e três sub-grades de 50x50m distribuídas aleatoriamente na área. Foi realizada análise estatística descritiva dos dados processados no laboratório e a análise espacial através de modelos de variância. De posse dos modelos ajustados na análise dos variogramas, realizou a interpolação pela krigagem para as frações granulométricas e através dos variogramas cruzados pela cokrigagem, as correlações dessas frações com os dados, obtidos pelo modelo digital de elevação, da altitude e a inclinação máxima do terreno da área e comparada, através dos mapas, essas mesmas correlações em densidades amostrais diferentes. A partir dos modelos de mapas gerados, chegou aos seguintes resultados: houve uma moderada variabilidade das frações granulométricas e uma moderada dependência espacial. De acordo com os parâmetros da variância cruzada a distribuição espacial da fração areia correlacionada com a altitude e com a inclinação máxima não diferenciou significativamente em relação aos níveis de densidade amostral 20x20m e 40x40m, praticamente não houve correlação entre a fração areia e a altitude, pois não apresentou um padrão definido de distribuição espacial. Pode-se concluir que a declividade influenciou na distribuição dos atributos físicos do solo. Como também foi avaliada a disponibilidade hídrica na área do pivô da Fazenda, foi constatada a forte correlação do atributo argila+silte com a capacidade de água disponível (CAD), enfatizando a dependência da disponibilidade hídrica em relação aos atributos físicos do solo. / In Brazil, few studied are related about soil sampling strategies in areas with more than one type soil and various features of the landscape, these strategies are important to map the spatial variability of physical attributes: size fractions, as well as the correlation of these with geomorphologic parameters: altitude and maximum slope of the sampled area of the multivariate extension of kriging, cokriging. This extension allows multivariate combination of two dependent variables to generate new information correlated with the model cross variance. The objective of this study was to evaluate the spatial correlation between the distribution of particle size fraction with the parameters of altitude and terrain slope through a maximum aggregate sample density (100x100 and 50x50m) with two levels of sample density, 20x20 and 40x40m. The study was an area of 180 ha, where fractions of collected soil at a sampling grid aggregate, ie an arrangement 100x100m sample and three sub-grids 50x50m randomly distributed in the area. We performed a descriptive statistical analysis of data processed in the laboratory and spatial analysis through models of variance. In possession of the adjusted models in the analysis of variogram for kriging interpolation performed for the fractions and through the variogram crossed by cokriging, the correlations of these fractions with the data obtained by digital elevation model, altitude and the maximum slope of the land area and compared, through maps, these same correlations in different sampling densities. From the models generated maps, it was reached the following results: there was a moderate variability in size fractions and a moderate spatial dependence. In accordance with parameters of cross (semi)variance the spatial distribution of the sand fraction correlated with altitude and the maximum slope did not differ significantly from the levels of sample density 20x20m and 40x40m, virtually no correlation between the sand fraction and altitude because it did not show a definite pattern of spatial distribution. It can be concluded that the slope influenced the distribution of soil physical attributes studieds. It was also quantified the water availability in the area under the center pivot equipment, it was found a strong correlation of the attribute clay + silt with TAW (total available water), emphasizing the dependence on water availability in relation to soil physical properties.

The size of a soot particle has an effect on smoke detector alarm activation. It is the purpose of this paper to identify changes to soot particle size and examine if those size changes effect smoke detector alarm times in the ceiling jet. Changes in particle size has been attributed to delays in detector activation, however, little evidence exists to support that particle size changes occur in the ceiling jet where detector activation occurs. This paper presents the results from laser scattering experiments and calculations conducted to support and validate the experimental findings. The laser scattering from various aerosols was collected, over time, to examine changes in particle size due to agglomeration in the smoke aging process. The laser scattering measurements were made at two linear polarizations, vertical (VV) and horizontal (HH), and scattering angles ranging from 20 to 155 degrees. A laser with a wavelength of 632.8 nm was used as a light source. The aerosol laser scattering results were then compared to the results from the Mie scattering theory. The Mie scattering theory was adjusted using a lognormal distribution to generate theoretical light scattering curves expected from a polydisperse aerosol typical of smoke. The collected data was examined using a combination of the Mie theory with various particle sizing techniques, including dissymmetry ratio and polarization ratio, to look for changes in laser scattering indicating changes in particle size.

The theoretical and experimental investigation of the novel in-line CMOS image sensor was performed. This sensor is aimed to investigate particle size distribution, particle concentration and shape in hydraulic liquid in order to implement the proactive maintenance of hydraulic equipment. The existing instruments such as automatic particle counters and techniques are not sufficiently enough to address this task because of their restricted sensitivity, limit of concentration to be measured and they cannot determine particle shape. Other instruments cannot be used as inline sensors because they are not resistant to the arduous conditions such as high pressure and vibration. The novel mathematical model was proposed as it is not possible to use previously developed techniques based on using optical system and complicated algorithms. This model gives the output signal of the image sensor depending on the particle size, its distance from the light source (LED) and image sensor. Additionally, the model takes into account the limited exposure time and particle track simulation. The results of simulation based on the model are also performed in thesis. On the basis of the mathematical model the image processing algorithms were suggested in order to determine particle size even when this size is lower than pixel size. There are different approaches depending on the relation between the size of the particle and the pixel size. The approach to the volume of liquid sample estimation was suggested in order to address the problem of low accuracy of concentration measurement by the conventional automatic particle counters based on the single photodiode. Proposed technique makes corrections on the basis of particle velocity estimation. Approach to the accuracy estimation of the sensor was proposed and simulation results are shown. Generally, the accuracy of particle size and concentration measurement was considered. Ultimately, the experimental setup was used in order to test suggested techniques. The mathematical model was tested and the results showed sufficient correlation with the experiment. The zinc dust was used as a reference object as there are the particles within the range from 1 to 25 microns which is appropriate to check the sensitivity. The results of experiments using reference instrument showed the improved sensitivity and accuracy of volume measured compared to the reference one.

Com a crescente diminuição de recursos minerais e o alto custo envolvido na construção da estrutura de uma mina, a recuperação máxima possível de uma jazida vem se tornando fundamental. Para isso além da escolha do método de lavra ter a necessidade de ser feito cautelosamente, é possível lançar mão de métodos adicionais de recuperação, como por exemplo, a recuperação de pilares. Essa pesquisa foi baseada na determinação da caracterização do enchimento (backfill cimentado) utilizado nas câmaras vazias que possibilita a posterior recuperação dos pilares. A caracterização do enchimento é composta da determinação da resistência simples do backfill necessária para que o enchimento cumpra com seu objetivo, desenvolvimento da classificação granulométrica ótima para os agregados e dosagem de cimento e água para alcançar a resistência proposta. A metodologia desenvolvida para obter a nova caracterização é composta de várias etapas que incluem pesquisas em campo e trabalhos em laboratório. Primeiramente, foram obtidos através de análise em campo os parâmetros de dosagem de cimento e classificação granulométrica dos agregados já utilizados na planta de fabricação do enchimento, bem como sua resistência correspondente. Em seguida definições teóricas da dosagem de cimento ideal e classificação granulométrica ótima foram realizadas com base na resistência à compressão simples que foi identificada como necessária para cumprir com as solicitações geomecânicas do maciço rochoso, então posteriormente, a nova caracterização definida teoricamente foi posta à prova através da confecção de corpos de prova de backfill, seguido de execuções de ensaios de compressão. Durante a primeira etapa da metodologia, já se pôde identificar que os agregados possuíam um alto índice de partículas tamanho argila que estavam afetando os resultados de resistência obtidos com a caracterização empregada inicialmente. A partir disso se optou por construir a curva granulométrica ótima sem essa fração. A resistência à compressão simples calculada de 2,69 MPa, foi obtida com base no planejamento de longo prazo que prevê a total recuperação dos pilares existentes na mina. Dessa maneira toda a área que será minerada foi considerada como um único bloco. Finalmente, foi identificada a dosagem de cimento sendo de 4% em peso, que juntamente com a granulometria ótima é capaz de alcançar os valores esperados de resistência. Para que o planejamento da produção da mina durante os próximos anos de vida útil seja efetivamente cumprido, o enchimento deverá prover à mina estabilidade geomecânica local a nível de câmaras abertas com paredes verticais de backfill estáveis e também estabilidade global a nível de contato entre níveis e galerias de acesso. Isso somente será alcançado se a nova caracterização for corretamente aplicada. / As a consequence of the ongoing reduction of mineral resources and the high cost involved in the construction of a mine, the maximum recovery of a mineral deposit becomes a fundamental issue. Therefore, besides the need of caution on the choice of the mining method, it is possible to make use of additional recovery methods, such as the recovery of pillars. This research was based on the determination of the characterization of the fill (cemented backfill) used in avoid stopes that allows the subsequent recovery of adjacent pillars. The characterization of the fill consists of determining the uniaxial compressive strength of the backfill required for an efficient filling, developing an optimal particle-size distribution for the aggregates and finding the cement-water ratio necessary to reach the desired resistance. The methodology developed to obtain the new characterization is comprised of several steps which include field work and laboratory tests. First, cement dosing parameters and particle size of the aggregates (already used at the filling manufacturing plant), as well as their corresponding strength, were obtained through analyses in the field work. Then, theoretical definitions of the ideal cement dosing and optimal particle-size analysis were carried out based on the uniaxial compressive strength that has been identified as necessary to comply with the geomechanical requests from the rock mass, and then later, the new theoretical characterization was tested by making backfill samples, followed by execution of compression tests. During the first stage of this methodology, it has been identified a high proportion of clay particle size for the aggregates, that have affected the strength results obtained from the characterization used initially. From this point, we decided to build the optimal particle-size curve without this fraction. Uniaxial compressive strength, calculated as 2.69 MPa, was obtained from the long-term planning that determines the full recovery of the existing pillars in the mine. In this way, the entire area to be mined was considered as a single block. Finally, the cement dosing has been identified as 4% by weight, which together with the optimal particle size, is able to achieve the expected strength values. In order to effectively fulfill the mine production planning over the next years of lifespan, the filling should provide the mine local geomechanical stability at open stopes level, with vertical walls of stable backfill, and also global stability at the contacts between levels and access galleries. This will only be achieved if the new characterization is correctly applied.

O objetivo do presente estudo foi avaliar o desempenho, saúde intestinal e metabolizabilidade de dietas para frangos de corte alimentados com o uso contínuo ou mudança brusca de diferentes rações à base de milho e sorgo moído ou inteiro. No Exp. 1 foi estudada a mudança no tipo de grão com as dietas: M100% (ração à base de milho); S100% (ração à base de sorgo); M:S50% (ração à base de 50% milho e 50% sorgo); PS-M (ração à base de sorgo na fase pré-inicial e milho nas demais fases); PM-S (ração à base de milho na fase pré-inicial e sorgo nas demais fases). No Exp. 2 foi estudada a mudança na forma do grão de sorgo: Sm100% (ração à base de sorgo moído); Si100% (ação à base de sorgo inteiro); PSm-Si (ração à base de sorgo moído na fase pré-inicial e inteiro nas demais fases) e PSi- Sm (ração à base de sorgo inteiro na fase pré-inicial e moído nas demais fases). Os experimentos foram conduzidos em um delineamento em blocos casualizados (blocos no tempo) para avaliar o desempenho e epitélio jejunal (r=8), microbiota intestinal (r=4) e metabolizabilidade das dietas (r=10). As mudanças entre milho e sorgo não alteraram o desempenho, epitélio jejunal nem a metabolizabilidade das rações, mas influenciaram a porcentagem de Clostridium, Weissella, Bacillus e Alkaliphilus no intestino delgado e Lactobacillus e Desulfotomaculum nos cecos. O uso de sorgo inteiro piorou o desempenho aos sete dias. Aos 40 dias, Sm100% e PSm-Si apresentaram desempenhos semelhantes, PSi-Sm apresentou menor ganho de peso, mas melhor conversão alimentar e Si100% apresentou o pior desempenho. Si100% e PSm-Si apresentaram aumento no peso relativo da moela e na metabolizabilidade das rações, assim como diminuição de Clostridium e aumento de bactérias das famílias Actinomycetales e Bacillales no intestino delgado, Si100% resultou em menor porcentagem de Alkaliphilus e Enterococcus que Sm100% nos cecos. Conclui-se que a melhor estratégia de uso do sorgo é a substituição total de milho por sorgo moído ao alojamento com posterior mudança para sorgo inteiro, pois não afeta o desempenho e epitélio jejunal das aves, melhora a metabolizabilidade das rações e potencializa a redução de Clostridium no intestino delgado de frangos de corte. / The aim of this study was to evaluate performance, intestinal health and metabolizability of diets in broilers fed different corn- or sorghum (ground or whole)- based diets, continuously or with abrupt change between the diets. Exp. 1 - Change in the type of grain: C100% (corn-based diet); S100% (sorghum-based diet); C:S50% (50% corn and 50% sorghum-based diet); PC-S (corn-based diet in pre-starter phase and sorghum-based diet in other phases); PS-C (sorghum-based diet in pre-starter phase and corn-based diet in other phases). Exp. 2 - Change in the form of sorghum grain: Gs100% (ground sorghum-based diet); Ws100% (whole sorghum-based diet); PGs-Ws (ground sorghum-based diet in pre-starter phase and whole sorghum-based diet in other phases); PWs-Gs (whole sorghum-based diet in pre-starter phase and ground sorghum-based diet in other phases). Experiments were conducted in a randomized block design for to evaluate performance and jejunal epithelium (r=8), intestinal microbiota (r=4) and metabolizabilty of diets (r=10). The changes between corn and sorghum did not affect performance, jejunal epithelium or metabolizability of the diets, but influenced the genera Clostridium, Weissella, Bacillus and Alkaliphilus in the small intestine, and Lactobacillus and Desulfotomaculum in the caecum. Whole sorghum resulted in decreased performance at seven days of age. At 40 days, Gs100% and PGs-Ws showed similar performance, PWs-Gs showed lower weight gain and the best feed conversion rate, and Ws100% showed the worst performance. Ws100% and PGs-Ws resulted in the biggest gizzard relative weight and the highest diet metabolizability values, as well as the lowest level of Clostridium and highest level of Actinomycetales and Bacillales in the small intestine. Ws100% showed lower level of Alkaliphilus and Enterococcus than Gs100% in the caecum. The best strategy to use sorghum in broilers diets is replacing 100% of corn for ground sorghum since the first day followed by change to whole sorghum, because this diet did not affect performance or jejunal epithelium, improved diet metabolizability values, and reduced Clostridium in the small intestine of broilers.

Approximately 1500 km (43%) of the strategic Scottish trunk road network drainage asset takes the form of Highway Filter Drains (HFDs). However, despite their popularity, they are prone to clogging, therefore they have an estimated operational life-cycle of ten-years. This research was undertaken to investigate the complex inter-relationship between catchment characteristics, road dynamics and the physical characteristics of the road to establish the key factors that govern the generation and spatial variability of Road-Deposited-Sediment (RDS). The aim being to establish the impact RDS Particle Size Distribution (PSD) has on clogging and the operational life-cycle of HFDs. The research adopted an integrated approach, incorporating: (i) a Field Study to investigate RDS PSD grading envelopes across the Scottish trunk road network, (ii) a HFD Field Survey (HFD-FS) to investigate the current condition of HFDs across a range of catchments, (iii) a HFD Field Study to establish whether, or not, graded stone PSD envelopes comply with specification requirements when first placed in the trench, (iv) 3 HFD Field Studies to assess the level of risk of system failure through evaluating the causes and quantifying the individual, cumulative and influencing factors which contribute to the evolution of clogging in HFDs, and (v) a Field Study utilising Ground Penetrating Radar data to explore why stratified (clogged) layers evolve within some HFDs. Based on the results of this research, design and maintenance procedures were then identified to improve the performance of HFDs. Results established that Scottish trunk roads operate under variable catchment characteristics and road dynamics, with the condition and specification of the road surface, volume of traffic, road geometry, number of running lanes and adjacent land use governing the generation and spatial variability of RDS. Five of the nine trunk road RDS PSD profiles shared a peak particle diameter of 425 μm, two had a peak of 600 μm, one had a peak of 1180 μm and one resulted in a peak of 2120 μm. Particles >1000 μm were mostly mineral or asphalt and it was shown that there is a direct link between the factors that govern the generation and spatial variability of RDS and those that govern the evolution of clogging and actual operational life-cycle of HFDs. The HFD-FS revealed that 69% were assigned Filter Drain Condition Index ratings of 3 or below, which identifies these as having exceeded the ten-year estimated operational life-cycle. 94% of those deemed to have reached the end of their operational life-cycle were over-the-edge (OTE) HFDs, which supports the assertion that pre-treatment would increase their operational life-cycle. Results also established that introducing a kerb-line and gully-pots or grass-strip between the road and the HFD significantly reduced the indices of particle size composition d50 and d90 and percentage of RDS retained at depths spanning 0 - 400 mm, compared to OTE HFDs with comparable catchment characteristics and road dynamics. Based on these results, the operational life-cycle of HFDs with a kerb-line and gully-pots and OTE HFDs with a grass-strip can be expected to exceed twenty-years, if catchment characteristics and road dynamics are representative of those in this study. This research also identified that compacting Type B graded stone with ‘heavy vibrating machinery’ during construction could potentially contribute to clogging. It was also established that HFD harrowing may exacerbate clogging because the process of disintegrating the cake-layer mobilises an otherwise rigid and compacted RDS mass and this is more likely to penetrate deeper into the HFD and inundate the HFD during a storm event. These findings indicate that current HFD construction and maintenance practice could have a detrimental impact on the effective operational life-cycle of HFDs. Overall, this research study has demonstrated that there are considerable uncertainties related to PSD grading envelopes and percentage of RDS migrating from roads to HFDs. It is clear therefore that one of the most notable findings of this research is that given the scale of strategic trunk road networks, assuming a single HFD operational life-cycle profile, for a trunk road or trunk road network, is highly unlikely to be representative of a HFD at the local level. It follows then that the widely accepted estimated ten-year operational life-cycle for HFDs, does not reflect the actual operational life-cycle of HFDs.