Today 70 percent of the people residing in nursing homes are undernourished. One way to avoid that an individual is affected by malnutrition it is a necessity that the meals is customized after special needs current among other things as energy and protein. Food record is a method that can be used to examine and evaluate if an individual is getting sufficient nutrition and energy to cover the daily needs. For those suffering from malnutrition it is recommended to eat energy and protein enriched diet. Aims The aim is to compare the intake of energy and macronutrients in a group of elderly people living in a nursing home in southern Sweden before and after the introduction of an energy and protein enriched diet based on newly developed recipes. Methods Food record was made during four days. Food record means that everything that is consumed by an individual is noted precisely. The food records were performed during four days and were then nutritionally calculated in DietistNet. In our analysis we used a paired t-test and a significance level of 5 percent were used in all hypothesis tests. Results The intake of energy, fat and protein significantly increased when the energy and protein enriched diet was introduced. The amount of finished portions that by size corresponded with a reference portion increased from 22 to 75 percent. Conclusion When the energy and protein enriched diet was introduced the intake of energy, protein and fat was significantly increased and the mean amongst the participants reached the nutrition recommendations from NNR. / Idag är cirka 70 procent av de som är bosatta på särskilda boende konstaterat undernärda eller i riskzonen för undernäring. En metod för att undvika att en individ drabbas av undernäring är att måltiderna anpassas efter särskilda behov med avseende på bland annat energi och protein. Kostregistrering är en metod som kan användas för att undersöka och värdera om en individ får i sig tillräckligt med makronutrienter och energi för att täcka dagsbehovet. För de som lider av undernäring kan en energi- och proteinrik kost (EPR-kost) rekommenderas. Syfte Syftet är att jämföra intag av energi och makronutrienter bland äldre på ett särskilt boende i södra Sverige före och efter införande av EPR-kost baserad på nyutvecklade recept. Material och metod Kostregistrering innebär att allt som konsumeras av en individ noteras med exakthet. Kostregistreringarna genomfördes under fyra dygn och näringsvärdesberäknades i DietistNet. I analysen användes ett parat t-test och en felrisk på 5 procent användes vid alla hypotestest. Resultat Intaget av energi, fett och protein ökade signifikant då EPR-kost infördes. Antalet uppätna portioner som storleksmässigt motsvarade en referensportion ökade från 22 till 75 procent. Slutsatser Då EPR-kost infördes ökade intaget av energi, protein och fett signifikant och medelvärdet bland deltagarna uppnådde näringsrekommendationerna enligt NNR.

Coal preparation plants are required in some cases to produce a high-grade product using a low specific gravity cut-point. For these situations, a second higher gravity separation would be desirable to generate a mid-grade product that can be utilized for electricity generation thereby maximizing coal recovery. A study was conducted to evaluate the potential of achieving efficient separations at two different density cut-points in a single stage using a three-product dense medium cyclone. Variations in density cut-point and process efficiency values were quantified as a function of the feed medium density, feed medium-to-coal ratio, and feed pressure using a three-level experimental design program. Results indicate the ability to effectively treat coal over a particle size range from 6mm to 0.15mm while achieving both low- and high-density cut-points up to 1.95 relative density. Ash content decreased from 27.98% in the feed to an average of 7.77% in the clean coal product and 25.76% in the middlings product while sulfur content was reduced from 3.87 to 2.83% in the clean coal product. The overall combustible recovery was maintained above 90% while producing clean coal products with ash and total sulfur content as low as 5.85 and 2.68%, respectively. Organic efficiency values were consistently about 95% and probable error values were in the range of 0.03 to 0.05, which indicates the ability to provide a separation performance equivalent to or better than traditional coal cleaning technologies.

The sinking of dense shelf waters down the continental slope (or “cascading”) contributes to oceanic water mass formation and carbon cycling. Cascading is therefore of significant importance for the global overturning circulation and thus climate. The occurrence of cascades is highly intermittent in space and time and observations of the process itself (rather than its outcomes) are scarce. Global climate models do not typically resolve cascading owing to numerical challenges concerning turbulence, mixing and faithful representation of bottom boundary layer dynamics. This work was motivated by the need to improve the representation of cascading in numerical ocean circulation models. Typical 3-D hydrostatic ocean circulation models are employed in a series of numerical experiments to investigate the process of dense water cascading in both idealised and realistic model setups. Cascading on steep bottom topography is modelled using POLCOMS, a 3-D ocean circulation model using a terrain-following s-coordinate system. The model setup is based on a laboratory experiment of a continuous dense water flow from a central source on a conical slope in a rotating tank. The descent of the dense flow as characterised by the length of the plume as a function of time is studied for a range of parameters, such as density difference, speed of rotation, flow rate and (in the model) diffusivity and viscosity. Very good agreement between the model and the laboratory results is shown in dimensional and non-dimensional variables. It is confirmed that a hydrostatic model is capable of reproducing the essential physics of cascading on a very steep slope if the model correctly resolves velocity veering in the bottom boundary layer. Experiments changing the height of the bottom Ekman layer (by changing viscosity) and modifying the plume from a 2-layer system to a stratified regime (by enhancing diapycnal diffusion) confirm previous theories, demonstrate their limitations and offer new insights into the dynamics of cascading outside of the controlled laboratory conditions. In further numerical experiments, the idealised geometry of the conical slope is retained but up-scaled to oceanic dimensions. The NEMO-SHELF model is used to study the fate of a dense water plume of similar properties to the overflow of brine-enriched shelf waters from the Storfjorden in Svalbard. The overflow plume, resulting from sea ice formation in the Storfjorden polynya, cascades into the ambient stratification resembling the predominant water masses of Fram Strait. At intermediate depths between 200-500m the plume encounters a layer of warm, saline AtlanticWater. In some years the plume ‘pierces’ the Atlantic Layer and sinks into the deep Fram Strait while in other years it remains ‘arrested’ at Atlantic Layer depths. It has been unclear what parameters control whether the plume pierces the Atlantic Layer or not. In a series of experiments we vary the salinity ‘S’ and the flow rate ‘Q’ of the simulated Storfjorden overflow to investigate both strong and weak cascading conditions. Results show that the cascading regime (piercing, arrested or ‘shaving’ - an intermediate case) can be predicted from the initial values of S and Q. In those model experiments where the initial density of the overflow water is considerably greater than of the deepest ambient water mass we find that a cascade with high initial S does not necessarily reach the bottom if Q is low. Conversely, cascades with an initial density just slightly higher than the deepest ambient layer may flow to the bottom if the flow rate Q is high. A functional relationship between S/Q and the final depth level of plume waters is explained by the flux of potential energy (arising from the introduction of dense water at shallow depth) which, in our idealised setting, represents the only energy source for downslope descent and mixing. Lastly, the influence of tides on the propagation of a dense water plume is investigated using a regional NEMO-SHELF model with realistic bathymetry, atmospheric forcing, open boundary conditions and tides. The model has 3 km horizontal resolution and 50 vertical levels in the sh-coordinate system which is specially designed to resolve bottom boundary layer processes. Tidal effects are isolated by comparing results from model runs with and without tides. A hotspot of tidally-induced horizontal diffusion leading to the lateral dispersion of the plume is identified at the southernmost headland of Spitsbergen which is in close proximity to the plume path. As a result the lighter fractions in the diluted upper layer of the plume are drawn into the shallow coastal current that carries Storfjorden water onto the Western Svalbard Shelf, while the dense bottom layer continues to sink down the slope. This bifurcation of the plume into a diluted shelf branch and a dense downslope branch is enhanced by tidally-induced shear dispersion at the headland. Tidal effects at the headland are shown to cause a net reduction in the downslope flux of Storfjorden water into deep Fram Strait. This finding contrasts previous results from observations of a dense plume on a different shelf without abrupt topography. The dispersive mechanism which is induced by the tides is identified as a mechanism by which tides may cause a relative reduction in downslope transport, thus adding to existing understanding of tidal effects on dense water overflows.

No description available.

Liquid waste discharged from industrial outfalls is categorized into two major classes based on their density. One type is the effluent that has a higher density than that of the ambient water body. In this case, the discharged effluent has a tendency to sink as a negatively buoyant jet. The second type is the effluent that has a lower density than that of the ambient water body and is hence defined as a (positively) buoyant jet that causes the effluent to rise. Negatively/Positively buoyant jets are found in various civil and environmental engineering projects: discharges of desalination plants, discharges of cooling water from nuclear power plants turbines, mixing chambers, etc. This thesis investigated the mixing and dispersion characteristics of such jets numerically. In this thesis, mixing behavior of these jets is studied using a finite volume model (OpenFOAM). Various turbulence models have been applied in the numerical model to assess the accuracy of turbulence models in predicting the effluent discharges in submerged outfalls. Four Linear Eddy Viscosity Models (LEVMs) are used in the positively buoyant wall jet model for discharging of heated waste including: standard k-ε, RNG k-ε, realizable k-ε and SST k-ω turbulence models. It was found that RNG k-ε, and realizable k-ε turbulence models performed better among the four models chosen. Then, in the next step, numerical simulations of 30˚ and 45˚ inclined dense turbulent jets in stationary ambient water have been conducted. These two angles are examined in this study due to lower terminal rise height for 30˚ and 45˚, which is very important for discharges of effluent in shallow waters compared to higher angles. Five Reynolds-Averaged Navier-Stokes (RANS) turbulence models are applied to evaluate the accuracy of CFD predictions. These models include two LEVMs: RNG k-ε, and realizable k-ε; one Nonlinear Eddy Viscosity Model (NLEVM): Nonlinear k-ε; and two Reynolds Stress Models (RSMs): LRR and Launder-Gibson. It has been observed that the LRR turbulence model as well as the realizable k-ε model predict the flow more accurately among the various turbulence models studied herein.

The use of dense CO2 in polymer processing can provide a response to the need for more environmentally-friendly industrial processes. Products with high-purity, sterility, and porosity can be achieved using dense gas technology (DGT). Currently, DGT has been used in different aspects of polymer processing including polymerization, micronization, and impregnation. Due to its solubility in polymers, CO2 can penetrate and plasticize polymers, while impregnating them with low-molecular weight CO2 -soluble compounds. Biodegradable polymers and other medical-grade polymers have benefited from the application of DGT. Dense CO2 processing properties of inertness, non-toxicity, and affinity for various therapeutic compounds are specifically advantageous to the medical and biomedical industries. In this work, the different applications of DGT in polymer processing are revised, then implemented. The polymerization of polycarbonate (PC) and polycaprolactone (PCL) in dense CO2 are presented. The syntheses of both polymers were successful and were aided by the use of dense CO2 . A multi-stage approach using dense CO2 as a sweep fluid to extract the PC polymerization by-product phenol is reported. Polycaprolactone was synthesized with varying temperatures and dense CO pressures, then impregnated with a CO2 -soluble therapeutic agent. The impregnated PCL acted as a drug reservoir with a drug-loading of 27wt% and a sustained drug release profile was observed for all samples over several days. Polymer blends of PC/PCL have potential industrial and biomedical applications both in vivo and in vitro. The applicability of PCL can be extended by enhancing its mechanical properties by creating a bio-blend with a stronger polymer such as PC. In this work, PC/PCL nonporous and porous blends were produced. Three novel dense CO2 blending techniques were used. The macroporous PC/PCL blend was impregnated with a therapeutic agent using CO2 as the carrier. A drug loading of 20wt% was achieved and sustained drug release was observed over 3 days. The applicability of dense CO2 in polymer processing was further demonstrated by sterilizing macroporous PC/PCL blends and soft hydrogels with dense CO2 . The PC/PCL blends and hydrogels were inoculated with vegetative bacteria and bacterial endospores. Industrial standard sterilization levels were achieved.

Cette thèse met en avant une démarche originale, celle de faire cohabiter l'utilisation d'une technologie moderne, au sein d'une étude archéologique conventionnelle centrée sur l'architecture grecque. L'utilisation de la modélisation 3D dans ce projet doctoral nous amène indubitablement à explorer de nouvelles problématiques en archéologie grecque. Pour ce faire, une réflexion sera menée sur les apports de cette technologie aux sciences archéologiques. En effet, la restitution d'un édifice antique en 3D implique des questionnements sur la réalité virtuelle créée. La modélisation 3D se fonde sur du matériel archéologique partiel altéré par le temps. C'est pourquoi il est nécessaire de prendre du recul face à une image 3D qui peut idéaliser une réalité archéologique. Notre étude s'appliquera aussi à apporter des solutions permettant de remédier à ces complications liées à la restitution virtuelle. De plus, la restitution 3D d'un édifice antique n'est pas une fin en soi. En d'autres termes, cette technologie doit par son approche intuitive apporter une nouvelle façon d'appréhender les questions qui touchent à la construction des édifices antiques. À commencer par les méthodes de constructions ou encore la faisabilité architecturale...etc. Dans un même temps, nous mènerons un examen architectural et archéologique dans le but de proposer une étude qui soit équilibrée et qui puisse être réutilisée par la recherche archéologique. Nos objectifs sont multiples et cette étude fait le vœu d'être ambitieuse. Pour cela, cette étude s'attellera à éviter l'écueil de proposer une approche ayant un cadre trop restrictif. C'est pourquoi nous envisageons de préférence une étude qui associera plusieurs groupes d'édifices aux fonctions différentes. De ce fait, en tenant compte d'un maximum de situations et de réalités archéologiques, notre examen gagnera en représentativité, tout comme cela lui assurera une probabilité plus grande d'être réutilisé dans la recherche pour d'autres applications liées à la restitution 3D. Cette thèse est aussi une occasion d'évoquer les questions liées à la valorisation du patrimoine culturel. Ce thème sera aussi abordé, car le partage du savoir ne doit pas seulement être destiné aux initiés, mais aussi auprès du grand public. Il s'agit là d'une mission essentielle que l'archéologie se doit de mener à bien. / This thesis puts forward a novel approach who will make cohabit together the use of a modern technology in a conventional archaeological study focused on Greek architecture. The use of 3D modeling in this doctoral project leads undoubtedly to explore new issues in the Greek archeology. To do this, we will consider to the benefits of this technology to archaeological sciences. Indeed, the restitution of an ancient building in 3D, involves questions on the virtual reality that created. 3D modeling is based on the archaeological material altered by the time. That is why, it is necessary to take a step back on a 3D picture that can idealize an archaeological reality. Our study will also apply to provide solutions to overcome these complications of the virtual restitution. Moreover, the 3D rendition of an ancient building is not an end in itself. In other words, this technology must provide a intuitive approach and a new way to understand the issues that affect at the construction of ancient buildings. Starting with the construction methods or architectural feasibility ... etc.. At the same time, we will conduct an architectural and archaeological examination in order to propose a study that is balanced and that can be reused by archaeological research. Our goals are many and this study wants to be ambitious. For this, this study will strive to avoid the pitfall of proposing an approach that is too restrictive. That is why we plan to combine preferably a study several groups of buildings with different functions. Therefore, taking into account a maximum of archaeological situations our study will be more representative, as this will ensure it a greater likelihood of being reused in the archeological studies. This thesis is also an opportunity to discuss issues related to the promotion of cultural heritage. This topic will also be addressed because the sharing of knowledge should not be accessible only to insiders, but it must also be affordable for the general public. This is an essential task that archeology must carry.

Dans la cellule hôte, Toxoplasma gondii se développe dans une vacuole parasitophore (VP) caractérisée par un réseau de nanotubes membranaires (RNM) dont la composition, le mécanisme de formation et la fonction sont obscures. Quelques protéines GRA, dont GRA2 et GRA6, sont sécrétées dans la VP à partir des granules denses puis ciblées au RNM. Cette localisation s'accorde avec l'hélice alpha-hydrophobe de GRA6 et les hélices alpha-amphipathiques de GRA2. Avant et après sécrétion dans la VP, les protéines GRA sont partiellement solubles. Le phénotype de parasites délétés de leur(s) gène(s) GRA2 et/ou GRA6 révèle que ces 2 protéines sont indispensables à la formation du RNM. J'ai montré 1) qu'avant leur insertion dans les membranes de la VP, la solubilité des protéines GRA est préservée grâce à des interactions hydrophobes avec peut être, des micelles de l'espace vacuolaire ; 2) que GRA12, une nouvelle protéine du RNM, n'interagit pas avec GRA2 dans ces membranes. 3) que l'adressage spécifique de GRA6 au RNM est déterminé par son domaine N-terminal hydrophile. 4) J'ai montré que GRA2 recombinante a une affinité pour le phosphatidyl inositol (4, 5) diphosphate avec lequel elle interagit via ses hélices alpha-amphipathiques. GRA2 déforme des liposomes de courbure membranaire importante pour générer de courts tubules membranaires. La tubulation est accentuée par GRA6 qui s'associe aux liposomes, quelque soit leur diamètre. Ces résultats valident le rôle direct de GRA2 et GRA6 dans la formation du RNM et laissent envisager un modèle de sa formation, dans lequel GRA6 favoriserait l'assemblage de vésicules lipidiques que GRA2 fusionnerait en tubules membranaires. / Within the host cell, Toxoplasma gondii multiplies in a parasitophorous vacuole (PV) characterized by a membranous nanotubular network (MNN). Its components, the mechanism of its formation and its function remain unknown. A few GRA proteins, including GRA2 and GRA6, are secreted from the dense granules into the PV and are targeted to the MNN. This location is in agreement with the hydrophobic alpha-helix predicted in GRA6 and with the GRA2 amphipatic alpha-helices. However, before and after their secretion in the PV, the GRA proteins are partially soluble. The phenotypic analysis of parasites deleted from their GRA2 and/or GRA6 gene(s) had shown that both these proteins are indispensable for MNN formation. During my thesis, I showed that before their insertion into the PV membranes, the GRA proteins solubility is preserved by establishing hydrophobic interactions, likely with micelles in the PV space. I also showed that GRA12, a novel MNN-associated protein, does not interact with GRA2 within these membranes. Using GRA6 as a model of study, I contributed to demonstrate that the GRA6 specific targeting to the MNN relies on its N-terminal hydrophilic domain. I demonstrated that recombinant GRA2 recognizes inositol (4, 5) biphosphate with which it interacts via its amphipatic alpha-helices. GRA2 deforms liposomes of steep membrane curvature into short membranous tubules. The tubulation is increased by GRA6 which associates with liposomes independently of their diameter. These results validate the direct role of both GRA2 and GRA6 in MNN formation and led us to propose a model in which GRA6 would tether vesicles, the fusion of which would be induced by GRA2.

Muitas questões ligadas à ecologia, biologia da conservação e biogeografia estão relacionadas aos efeitos de processos naturais ou antropogênicos sobre fragmentos, manchas ou ilhas. Na atualidade, para se compreender os efeitos da fragmentação e se propor medidas efetivas de conservação, torna-se cada vez mais importante analisar os fragmentos como parte de uma matriz que inclui não somente diferentes tamanhos de remanescentes e de floresta contínua, mas também outros elementos da estrutura da paisagem. Para tanto, quando comparamos formações com diferentes características ambientais, mesmo que inseridas em regiões próximas, para entendermos os mecanismos que levam ao desaparecimento de algumas espécies e beneficiam outras, é necessário considerar níveis de organização relacionados a atributos de espécies e populações. Determinados atributos podem ser indicadores ecológicos relevantes de pressões exercidas pelo ambiente na biologia das espécies, ao mesmo tempo em que demonstram relação com a função do organismo. Essa tese, em seu primeiro capítulo avalia como questões metodológicas e analíticas podem influenciar os resultados de estudos avifaunísticos e a relação da riqueza e abundância de espécies com o tamanho de fragmentos e manchas florestais. Observamos que a relação entre a riqueza e o tamanho das áreas foi afetada pela padronização do tempo de contagem por área. A utilização de contagens com raio ilimitado fez com que o número de espécies aumentasse significativamente somente nas maiores manchas de Floresta Ombrófila Mista. Considerando-se o acréscimo de registros obtidos em cada minuto de contagem, constatou-se que com nove minutos já haviam sido obtidos grande parte dos registros de espécies e contatos de aves. No segundo capítulo, foi investigado se a riqueza rarefeita e a abundância de aves diminuem com o decréscimo da área de fragmentos de Floresta Ombrófila Densa. Paralelamente buscou-se compreender como a avifauna é influenciada por características da vegetação dos fragmentos e do entorno destes. A abundância obtida em cada fragmento esteve significativamente relacionada ao tamanho das áreas, sendo mais elevada nos fragmentos maiores. As análises relacionando a riqueza rarefeita média dos fragmentos e as variáveis ambientais selecionadas mostraram que as variáveis de mancha foram mais importantes que as variáveis relacionadas à estrutura da vegetação no interior dos fragmentos. No terceiro capítulo, avaliamos como as comunidades de aves respondem diferentemente à fragmentação em regiões originalmente florestadas e à existência de mosaicos em regiões com manchas florestais (capões), situações características das regiões onde estão inseridas, respectivamente, as Florestas Ombrófilas Densa (FOD) e Mista (FOM). As áreas de FOM e FOD foram agrupadas quando relacionadas às variáveis ambientais e, menos fortemente, em relação ao tamanho. Aves com status migratório apresentaram correlação significativa com pelo menos um dos eixos, mostrando-se mais fortemente associadas às manchas de FOM e áreas maiores. O uso de áreas abertas pelas aves teve uma associação mais marcante com os fragmentos e manchas de menor tamanho. Nectarívoros e frugívoros/folívoros tiveram uma associação mais forte com os fragmentos de FOD, enquanto as espécies onívoras foram mais bem representadas nas manchas de FOM. Aves de sub-bosque foram significativamente relacionadas aos fragmentos de FOD e áreas de menor tamanho e aves que habitam o dossel estiveram correlacionadas principalmente às manchas de FOM. A partir dos resultados obtidos nas áreas estudadas na Mata Atlântica do sul do Brasil, onde os maiores remanescentes florestais tem menos de 200 ha, observamos que mesmo as áreas de menor tamanho podem ser importantes para a manutenção das comunidades de aves. Conhecer as respostas da fauna às modificações ambientais impostas pela intervenção humana torna-se fundamental para o planejamento de estratégias de manejo e conservação. / Many issues in ecology, conservation biology and biogeography are related to the effects of natural or anthropogenic processes over fragments, patches and islands. Nowadays, the evaluation of fragments in a landscape context, as elements of a matrix including not only fragments of different size and continuous forest, but also other elements of landscape structure, is becoming increasingly important in order to understand fragmentation effects and to propose effective conservation actions. Furthermore, when comparing formations with distinct environmental attributes, even when geographically near, it is necessary to consider organization levels related to species and populations attributes to understand the mechanisms that drive some species to extinction and other to success. Some attributes may be used as ecological indicators that reflect environmental pressures on species biology, at the same time that reflect relationships with organism functions. In the first chapter of this thesis, we evaluated how methodological and analytical approaches may influence the results of bird studies and the relationship between species richness/abundance and the size of forest fragments and patches. We observed that the relationship between species richness and size of areas was affected by the standardization of the time counting. Species number increased significantly in patches of Mixed Ombrophilous Forest when counting was performed with unlimited radius. When considering bird records computed in each sampling minute, we found that with nine minutes of sampling the most part of the species and contact records had already been obtained. In the second chapter we investigated if rarefied richness and abundance of birds reduce with decreasing area of fragments at Atlantic Ombrophilous Dense Forest. At the same time, we aimed to understand how bird assembly is influenced by attributes of vegetation within fragments and around them. Our results indicated that species abundance in each fragment was significant related to the fragment size, with the highest abundance in the largest fragments. The analyses carried out between mean rarefied richness and the selected environmental variables showed that patch variables were more important than variables related to vegetation structure within fragments. In the third chapter we evaluated how bird communities are influenced by fragmentation in areas originally forested and by nucleation processes in areas of mosaic of patchy forests, in Atlantic Ombrophilous Dense Forest (AODF) and Mixed Ombrophilous Forest (MOF), respectively. MOF and AODF areas were aggregated when related to environmental variables and, less strongly, in relation to size. Migrant birds had significant correlation with at least one ordination axis, showing a stronger association with MOF patches and largest areas. The use of open areas was markedly associated with smaller fragments and patches. Nectarivores and folivores/frugivores had a strong association with AODF fragments, while omnivore species were better represented in MOF patches. Understory birds were significantly related to AODF fragments and small areas, while canopy birds were correlated mainly to MOF patches. Considering our results obtained in Atlantic Forest in southern Brazil – where the largest forest remnants have less than 200 ha, we observed that even small areas may be important for the conservation of bird communities. The knowledge about wildlife responds to environmental modifications made by humans is critical for management and conservation planning in this scenario.

Made available in DSpace on 2016-06-02T19:10:27Z (GMT). No. of bitstreams: 1 6459.pdf: 4283564 bytes, checksum: 527069b2b33732466b82a6f78943d62f (MD5) Previous issue date: 2014-02-21 / Financiadora de Estudos e Projetos / This thesis presents the development of a new criterion which can indicate new compositions for amorphous metallic alloys. This new criterion was based on dense packing of spheres combined with the lambda criterion through the coordination number. The mathematical development is presented and a software was developed with the purpose of indicating alloys with best glass forming ability (GFA). This software includes and concatenates several other criteria. For this purpose, we performed a mathematical analysis of the criteria, which included: (i) (λmin) criterion which uses the minimum topological instability parameter and it is used as an indication of phase competition during the solidification. (ii) the γ parameter, which reflects the relative GFA between bulky metallic glasses (BMG) and it is based on characteristic temperatures, such as: the glass transition temperature - Tg, the crystallization onset temperature - Tx and the liquidus temperature - Tl. (iii) the parameter Zc that is the critical thickness for bulky glass formation, which corresponds to the maximum dimension in which the molten can be formed without any crystals precipitation and (iv) the parameter Rc that is the critical cooling rate for glass formation, which decreases inversely to the Zc values. Through a mathematical formalism combining all the parameters, the software can decide the most suitable composition range to produce a new alloy. The results are presented and compared with the ones available on the literature. Also, for comparison, new alloys were developed by using the new criterion. These results indicate good agreement with the literature and with the experimental data since it is not a general theory, but intends to meet some specific cases with a reasonable convergence and which still need to be better studied. / Esta tese apresenta o desenvolvimento de um novo critério para indicar novas composições de ligas metálicas amorfas. Este novo critério foi baseado no empacotamento denso de esferas combinado com o critério lambda através do número de coordenação. O desenvolvimento matemático é apresentado e um software que engloba e concatena diversos outros critérios foi desenvolvido com o propósito de indicar as melhores ligas metálicas com alta tendência à formação de vidros (GFA). Para tal, houve uma análise matemática dos critérios, entre eles: (i) o critério λmin, que usa o parâmetro de mínima instabilidade topológica, usado como indicativo da competição de fases durante a solidificação; (ii) o parâmetro γ, que reflete a GFA relativa entre vidros metálicos volumosos (BMG) com base nas temperaturas características como a temperatura de transição vítrea - Tg; temperatura de início de cristalização - Tx e a temperatura liquidus - Tl; (iii) o parâmetro Zc, que é a espessura crítica para a formação do vidro volumoso e que corresponde à máxima dimensão com que o fundido pode ser formado sem que haja precipitação de cristais e (iv) o parâmetro Rc, que é a taxa de resfriamento crítico para a formação de vidro a qual decresce inversamente aos valores de Zc. Através de formalismo matemático para combinar todos os parâmetros, o software pode decidir qual a faixa de composição mais adequada para a produção de uma nova liga. Os resultados são apresentados e comparados com a bibliografia existente, além de terem sido desenvolvidas ligas experimentais para comparação. Estes resultados indicam uma boa concordância com a literatura e com os dados experimentais, uma vez que não se trata de uma teoria geral, mas que pretende atender a alguns casos específicos com razoável convergência e que ainda precisam ser melhor estudados.