Doctor of Philosophy / Department of Animal Sciences and Industry / Robert D. Goodband / Two experiments evaluated effects of glycerol on pellet mill production and pig performance. In Exp. 1, increasing glycerol increased (quadratic; P < 0.01) pellet durability index through 9% added glycerol. Adding glycerol decreased (linear; P > 0.01) production energy (kWh/t). In Exp. 2, pigs were fed one of seven diets with no added soy oil or glycerol (control); the control diet with 3 or 6% added soy oil, 3 or 6% added glycerol, and 6 or 12% additions of a 50:50 soy oil/glycerol blend in a 26-d growth assay. Adding glycerol improved (P < 0.01) pellet durability compared to soy oil and the soy oil/glycerol blend treatments. Pigs fed glycerol had increased (linear, P < 0.03) ADG. Adding soy oil, glycerol, or the soy oil/glycerol blend resulted in similar final BW. Two experiments evaluated the effects of glycerol as a replacement for lactose on pellet mill production and nursery pig performance. In Exp. 1, pigs were fed one of ten treatments that included 0, 3.6, or 7.2% lactose or 0, 3.6, or 7.2 % glycerol and fed in either meal or pelleted form. Pellet durability index increased (linear; P < 0.01) with added lactose and glycerol. Glycerol decreased (linear; P < 0.01) production energy (kWh/t). There was a tendency (P < 0.06) for an inclusion level × diet form (meal or pellet) interaction observed for ADG. Pigs fed the pelleted diets containing the 7.2% glycerol inclusion had decreased ADG compared to all other treatments. In Exp. 2, pigs were fed one of fourteen diets that included 0, 3.6, 7.2, or 10.8% lactose or 0, 3.6, 7.2, or 10.8 % glycerol and fed in either meal or pelleted form. There was no effect (P < 0.27) of diet form, inclusion level, or source on ADG or ADFI. Eight experiments evaluated the effect of ingredients on the flow ability of ground corn. Flow ability of feed improved with added glycerol, especially when added to meal diets containing hammer mill ground corn. Specialty protein ingredients in powder form reduce flow ability, while fine lactose sources improved flow ability. Granulated ingredients improved flow ability.

The primary prerequisites for powder mixtures/granules intended for tableting is to posses the quality of (i) homogenous composition; (ii) acceptable flowability, (iii) sufficient compressibility; and (iv) anti-adhesiveness. The most important prerequisite for these powder mixture/granulates is undoubtedly the ability to flow, due to its effect on product quality, especially dose and dosage form uniformity. A comprehensive literature study on the flowability of powders revealed that flow is affected by physical properties such as molecular- and interparticle forces, particle size and size distribution, particle shape, particle density, surface structure of the particle, and particle packing geometry. Various flow tests are available to determine powder flow, each measuring a variety of the properties mentioned above, resulting in different flow results and a subsequent variation in the classification of powders. Particle characterization of a wide range of pharmaceutical fillers through SEM and particle size analysis, indicated considerable differences between physical properties of the various fillers, which suggested significant differences in their flow behaviour. Flow tests were conducted determining the critical orifice diameter (COD); percentage compressibility (%C); angle of repose (AoR) and flow rate (FR) of the fillers in the absence and presence of a glidant (0.25% Aerosil® 200). The results confirmed the expected differences in flow obtained from the various tests, with no one of the fillers achieving the same flow behaviour in all the tests. The difference in flow amongst the fillers for a specific test could, to a large extent, been correlated with specific physical properties of the particles within the powder bed. COD results illustrated the influence of particle size and shape and surface structure on the flowability of these materials, with fillers with a smaller average particle size, less spherical shaped particles and uneven / rough surface structures performing poorer than their counterparts. The percentage compressibility (%C) of the materials was affected by the shape and size of the particles and the density of the materials, whilst the packing geometry also affected flow behaviour. Particles with high density and a low internal porosity tended to posses free flowing properties. Powders with a larger difference in the ratio between their respective bulk and tapped densities/volumes presented better flow results. The AoR of the fillers was affected by the cohesiveness and friction between the particles as well as the shape, surface structure and size of the particles. This method was less discriminative in terms of indicating differences in the flow of powders with comparable physical properties. A further drawback of this method was the variation in results between repetitions, which is affected by the way the samples were handled prior to measurement. The flow rate (FR) of the fillers was predominantly affected by the density of the materials and the size, shape, and surface structure of the particles. Powders with a higher density seemed to exhibit a better flow rate, although some of the other factors affected the flow rate more when the densities were very close or identical. The following general rank order for the various fillers (as an average of their performance in all the tests) were established (with no glidant present): Cellactose® 80 > FlowLac® 100 > Prosolv® HD90 * Ludipress® > Emcompress® >Avicel® PH200 > Starlac® » Emcocel® 50M * chitosan » lactose monohydrate. Addition of a glidant failed to change the rank order significantly. During the final stage of the study an attempt was made to modify and/or refine the composite flow index (CFI) proposed by Taylor ef a/. (2000:6) through (i) inclusion of flow rate results in its computation and/or (ii) varying the contribution (percentage) of each test to the CFI (Taylor & co-workers used equal contributions, namely 33 V* %, in their calculation of the CFI). The results indicated that including the results from the flow rate test was not beneficial in terms of providing a more representative CFI (in fact it reduced the accuracy of the index). Next various weight ratios for COD, %C and AoR was used to determine the CFI of each filler, and an optimum ratio was found at 50%:40%:10% (COD:%C:AoR) resulting in the highest CFI for each powder and the widest range for the CFI (largest difference between minimum and maximum values). This ratio was found in the presence and absence of a glidant. At this ratio the CFI discriminated well between the different powders in terms of their flowability. Lastly, the flowability scale for powders as used by the USP (20007:644) for %C and AoR results was adapted and fitted on the CFI results obtained for the various powders. This scale provided an exceptional fit for the powders both in the absence and presence of a glidant) and offered an excellent means for the grouping and classifcation of powders based on their CFI. / Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2009.

The primary prerequisites for powder mixtures/granules intended for tableting is to posses the quality of (i) homogenous composition; (ii) acceptable flowability, (iii) sufficient compressibility; and (iv) anti-adhesiveness. The most important prerequisite for these powder mixture/granulates is undoubtedly the ability to flow, due to its effect on product quality, especially dose and dosage form uniformity. A comprehensive literature study on the flowability of powders revealed that flow is affected by physical properties such as molecular- and interparticle forces, particle size and size distribution, particle shape, particle density, surface structure of the particle, and particle packing geometry. Various flow tests are available to determine powder flow, each measuring a variety of the properties mentioned above, resulting in different flow results and a subsequent variation in the classification of powders. Particle characterization of a wide range of pharmaceutical fillers through SEM and particle size analysis, indicated considerable differences between physical properties of the various fillers, which suggested significant differences in their flow behaviour. Flow tests were conducted determining the critical orifice diameter (COD); percentage compressibility (%C); angle of repose (AoR) and flow rate (FR) of the fillers in the absence and presence of a glidant (0.25% Aerosil® 200). The results confirmed the expected differences in flow obtained from the various tests, with no one of the fillers achieving the same flow behaviour in all the tests. The difference in flow amongst the fillers for a specific test could, to a large extent, been correlated with specific physical properties of the particles within the powder bed. COD results illustrated the influence of particle size and shape and surface structure on the flowability of these materials, with fillers with a smaller average particle size, less spherical shaped particles and uneven / rough surface structures performing poorer than their counterparts. The percentage compressibility (%C) of the materials was affected by the shape and size of the particles and the density of the materials, whilst the packing geometry also affected flow behaviour. Particles with high density and a low internal porosity tended to posses free flowing properties. Powders with a larger difference in the ratio between their respective bulk and tapped densities/volumes presented better flow results. The AoR of the fillers was affected by the cohesiveness and friction between the particles as well as the shape, surface structure and size of the particles. This method was less discriminative in terms of indicating differences in the flow of powders with comparable physical properties. A further drawback of this method was the variation in results between repetitions, which is affected by the way the samples were handled prior to measurement. The flow rate (FR) of the fillers was predominantly affected by the density of the materials and the size, shape, and surface structure of the particles. Powders with a higher density seemed to exhibit a better flow rate, although some of the other factors affected the flow rate more when the densities were very close or identical. The following general rank order for the various fillers (as an average of their performance in all the tests) were established (with no glidant present): Cellactose® 80 > FlowLac® 100 > Prosolv® HD90 * Ludipress® > Emcompress® >Avicel® PH200 > Starlac® » Emcocel® 50M * chitosan » lactose monohydrate. Addition of a glidant failed to change the rank order significantly. During the final stage of the study an attempt was made to modify and/or refine the composite flow index (CFI) proposed by Taylor ef a/. (2000:6) through (i) inclusion of flow rate results in its computation and/or (ii) varying the contribution (percentage) of each test to the CFI (Taylor & co-workers used equal contributions, namely 33 V* %, in their calculation of the CFI). The results indicated that including the results from the flow rate test was not beneficial in terms of providing a more representative CFI (in fact it reduced the accuracy of the index). Next various weight ratios for COD, %C and AoR was used to determine the CFI of each filler, and an optimum ratio was found at 50%:40%:10% (COD:%C:AoR) resulting in the highest CFI for each powder and the widest range for the CFI (largest difference between minimum and maximum values). This ratio was found in the presence and absence of a glidant. At this ratio the CFI discriminated well between the different powders in terms of their flowability. Lastly, the flowability scale for powders as used by the USP (20007:644) for %C and AoR results was adapted and fitted on the CFI results obtained for the various powders. This scale provided an exceptional fit for the powders both in the absence and presence of a glidant) and offered an excellent means for the grouping and classifcation of powders based on their CFI. / Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2009.

Simulations are powerful and important tools for gaining insight into powder processes. Ultimately, simulations have the potential to replace experiments. Thus, accurate models and insight into the essential factors for descriptions of powder behaviour are required. In this thesis, discrete element method (DEM) simulations of granule flow and compression were evaluated to deduce parameters and potential models essential for the experimental and numerical correspondence. In addition, the evolution in tablet microstructure during compression was studied using mercury porosimetry. Granule flow was measured using angle of repose, discharge rate, and shear. The granular flow depended primarily on particle shape and surface texture due to the mutual influence of these two parameters on the inter-particle forces. Rolling friction stabilised both the heap formation and promoted shear in the elastic quasi-static flow regime. Thus, rolling friction was established to be an essential simulation parameter for the correspondence to experiments. Current compression models often neglect the elastic compact deformation during particle loading. In this thesis, two fundamentally different models were evaluated with focus of including the elastic deformation. The first model comprised a maximal particle overlap, where elastic deformation commences. The second model accounted for the contact dependence and impingement at high relative densities. This model was based on a truncated-sphere followed by a Voronoi extension. The validity of the models was demonstrated by the elastic qualitative correspondence to experimental compressions for ductile materials. In tablets, the void (inter-granular pore) diameter was dependent on the degree of compression. Thus, the degree of compression provides an indication of the tablet microstructure. The microstructure was subsequently observed to be related to the tablet tensile strength as inferred from a percolation threshold required for formation of coherent tablets. In summary, this thesis has shed light onto the potential of simulating flow and compression of granulated pharmaceutical powders using DEM. Continuous work in the area are required to further improve the models to increase the experimental and numerical correspondence.

The West has long been an important geographic and symbolic space for the United States. In the 19th and 20th centuries that space became the subject of numerous popular works of fiction, first in print and later in the cinema. These texts eventually formed a specialized genre, the Western, which had its own conventions, styles, and themes. Wallace Stegner's Angle of Repose and Fred Zinnemann's High Noon, both seminal western texts from the mid-twentieth century, seek to reinterpret those conventions. While the Western is often characterized as a genre of violent masculinity and rugged individualism, these two texts employ conventional Western motifs in an effort to articulate a metafictional criticism of those ideas. Ultimately, they posit a reality in which traditional portrayals of the West lead to alienation, while also advocating an escape from that alienation.

Slope processes are important to understand if we are to protect fragile environments. Every year slope development in weak soils put nearby infrastructure in risk zones of sliding and ravine erosion takes away field areal from farmers as they grow even larger. Many methods for doing a risk analysis of a slope and its soil are complicated and require a lot of equipment. A simple way to do a slope investigation is explained in this report, along with its advantages and disadvantages. The authors construct a shear ring, an apparatus to measure peak shear stress of soils before fracturing. LIDAR scanning of two small ravines are also made to illustrate how laser scanning can be used to accurately measure denudation in slopes. The results vary, the shear ring is mostly a success aside from errors caused by difficulty in taking representative samples and disturbance. Some of the laboratory work made to determine material properties fail at giving good results, often a result of bad samples or disturbance in the tests. The LIDAR is determined to be a good instrument when working with slope development. / Sluttningsprocesser är viktiga att förstå och studera om vi ska kunna skydda känsliga områden. Varje år så sätter svaga jordar i sluttningar närliggande infrastruktur i riskzonen för att ligga på ett glidplan som snabbt kan släppa om jorden blir för blöt eller om för mycket tyngd läggs ovanpå. Samtidigt så tar ravinerosion bort åkerareal från bönder varje år medan ravinerna blir större och större. Många metoder för att göra riskanalyser av sluttningar är komplicerade och kräver mycket utrustning. I denna rapport så testas ett enkelt sätt att göra en sluttningsanalys med tillhörande diskussion kring dess fördelar och nackdelar. Författarna konstruerar en shear ring, en apparat som används för att testa jordens möjlighet att motstå en applicerad kraft. Två sidoraviner scannas även med LIDAR som en bas för att studera denudation i sluttningar. Resultaten varierar, shear ring-apparaturen bestäms som väl fungerande med undantag från vissa utförda tester, där svårigheter uppstod då jordproverna var störda eller mindre representativa. Vissa av laborationerna på jorden misslyckas med att ge bra värden, vilket ofta är ett resultat av dåliga eller störda prover. Laserscanningar av raviner med LIDAR bestäms som ett bra sätt att studera utvecklingen i sluttningar samt att mäta erosion.

Diploma thesis describes design and function verification of device for filling tap hole of electric arc furnace with tap hole diameter from 190 mm to 250 mm. The theses includes drive design calculation of chute swinging movement and bearing calculations. Another part of the thesis deals with verification of device functions which it is completed with process description of creating DEM simulation in program YADE. The thesis also includes basic experiments for determination angle of internal friction, angle of repose, coefficient of restitution and angle of material friction on a steel surface. Drawing documentation of selected assemblies is part of the thesis.

This thesis originated as a part of the PhD research carried out by Mgr. Radek Suchomel. To calibrate a hypoplastic model for granular materials a large number of laboratory tests was needed and a part of the testing constitutes the present thesis. The hypoplastic model by von Wolffersdorff (1996) has eight materials parameters. The critical state fiction angle φc', which was obtained directly by the measurement of the angle of repose, is one of the eight parameters. Other parameters are determined form the results of experiments and empirically. Aim of this thesis was to carry out field and laboratory tests, to determine selected soil properties and to interpret them with regard to the variability of the soil in the selected face of the sand pit. The material for investigation comes from the south part of the Cretaceous Třeboň Basin in the South Bohemia from the Kolný sand pit. The pit is located in the upper part of the Klikov layers. The fluvial layers are characterised by rhythmical variation of gravely sands, sands and sands with dark grey clayey inclusion. Samples were taken in the face of the sand pit with the dimensions of 9 x 36 m. The following tests were performed: drained triaxial compression test (38 samples), oedometric compression test (38 samples), measurement of the angle of repose...

One of the current testing method (the Dry Flow test) to qualify resin for use in production in the rotomolding process has been shown to have many flaws in both equipment and procedure. Research was done here to investigate a possible alternative that could eliminate some of these testing deficiencies. By reducing equipment and operator errors, the testing of materials becomes more valuable of an exercise. The Angular Flow test developed in this research can increase repeatability. By coming to understand the rotational molding process better, an evaluation that can give more valid information was devised.

During the pressing of powder mixtures to make cemented carbide tools, the degree to which the powder spreads to fill the die and to which it compacts is uncertain. This leads to inconsistent dimensions and densities in the finished product. This performance changes with the composition of the powder, including the amount of pressing agent in the mixture, the particle size distribution and particle shape. One way to quantify the degree to which powder will spread to fill the mold evenly is using the property called 'flowability'. There are several techniques by which flowability can be measured, and each technique does not always give results that are consistent with other techniques. It is, therefore, important to know what technique(s) predict(s) the final behavior of the powder in this application before it is used in quality assurance or to design a process. Additionally, powder size distribution and shape metrics are measured using dynamic image analysis to investigate if there is any relationship between key values of these properties and compaction behavior. In this study, static Angle of repose, Tap Density, Hall flow time and Powder rheometry were benchmarked against each other and against the dimensions of presses and liquid phase sintered tool inserts to understand which technique had the strongest dependence on the compactability, which was defined as the ratio of the tallest dimension in the insert to the smallest. After the study, the results showed that a more extensive particle size distribution improves the compaction properties and that the powders with a higher resistance to a rotating blade tend to have better compaction properties. On the other hand, a clear pattern for the results of all measurement methods and the correlation between the compaction behavior of the carbide tools could not be discerned. In conclusion, the study showed that it is possible to determine a relationship between the results of measurement methods and the compaction behavior of powders. By using simple tests to predict the compactability properties, both money and time can be saved on the research of new, improved powder. Furthermore, the implementation of this study can lead to even better pressing and compactibility properties in the future for cemented carbide tools. / Vid pressning av pulverblandningar för tillverkning av hårdmetallverktyg är det osäkert i vilken grad pulvret sprider sig för att fylla matrisen och i vilken grad det komprimeras. Detta leder till inkonsekventa dimensioner och densitet i den färdiga produkten. Denna prestanda förändras med pulvrets sammansättning, inklusive mängden bindemedel som finns i blandningen, partikelstorleksfördelningen och partikelformen. Ett sätt att kvantifiera i vilken grad pulvret sprids för att fylla formen jämnt är att använda den egenskap som kallas "flytbarhet". Det finns flera tekniker för att mäta flytbarhet, och varje teknik ger inte alltid resultat som överensstämmer med andra tekniker. Det är därför viktigt att veta vilken eller vilka tekniker som förutsäger pulvrets slutliga beteende i denna tillämpning innan den används i kvalitetssäkring eller för att utforma en process. Vidare mäts pulvrets partikelstorleksfördelning och form med dynamisk bildanalys för att undersöka om det finns något samband mellan nyckelvärden för dessa egenskaper och komprimeringsbeteendet. I den här studien jämfördes statisk rasvinkel, tappdensitet, hallflödestid och pulverreometri samt med dimensionerna på pressar och sintrade verktygsinsatser i vätskefas för att förstå vilken teknik som hade det starkaste beroendet på kompatibiliteten, vilket definieras som förhållandet mellan den högsta dimensionen i insatsen och den minsta. Efter studien visade resultaten att en mer omfattande partikelstorleksfördelning förbättrar komprimeringsegenskaperna och att pulver med högre motståndskraft mot ett roterande blad tenderar att ha bättre komprimeringsegenskaper. Vidare kunde inte ett tydligt mönster för resultaten för alla mätmetoder och sambandet på komprimeringbeteendet för hårmetallverktygen urskiljas. Sammanfattningsvis visade studien på att det går att använda sig av mätmetoder för att kunna urskilja ett samband mellan resultaten på mätmetoderna och pulvers kompaktibillitetsegenskaper. Genom att använda sig av enkla mätningar för att kunna förutsäga kompaktibilitetsegenskaper samt komprimeringsbeteende kan både pengar respektive tid sparas. Vidare kan genomförandet av denna studie i framtiden leda till ännu bättre pressnings- samt kompaktibilitetsegenskaper för hårdmetallverktyg.