[Afhandling]--[København], [1992]. / Bibliogr. p. 251-262.

L'évolution du cadre réglementaire et la prise de conscience générale des enjeux environnementaux et de santé publique sont à l'origine d'une profonde modification du paysage des solvants. L'avènement de solvants alternatifs, comme les agro-solvants, nécessite le recours à des outils physico-chimiques systématiques de caractérisation de leurs propriétés solubilisantes. L'approche des paramètres de Hansen, issue de la théorie de Hildebrand, propose une représentation des principales interactions moléculaires en solution. Ses performances applicatives ont été éprouvées pour la caractérisation des agro-solvants émergents et l'étude de la solubilisation de solutés moléculaires et macromoléculaires. Alternativement, le modèle COSMO-RS combine chimie quantique et thermodynamique statistique pour la prédiction des propriétés moléculaires à l'état liquide. Les performances de ce modèle ont été évaluées et exploitées pour rendre compte des phénomènes de solubilisation de solutés complexes tels que la nitrocellulose et le C60-fullerène. Permettant de traduire les deux mécanismes principaux de solubilisation (similarité et complémentarité), les descripteurs issus de COSMO-RS ont été mis à profit pour forger de nouveaux paramètres de solubilité aussi simples que ceux de Hansen mais plus rigoureux scientifiquement. Cette jouvence des paramètres de solubilité s'appuie sur la prise en compte des interactions acide-base de Lewis et le concept nouveau de COSMOmorphe permettant le calcul des interactions dispersives. Les connaissances ainsi acquises ont permis l'élaboration d'une microémulsion dégraissante verte dont l'efficacité repose sur un mécanisme original de décapage dégraissant. / The evolution of regulations and the global awareness as result of health and environmental issues are deeply modifying the solvent landscape. With the increasing demand for alternative solvents, such as biosolvents, there is a need for systematic physicochemical tools for the characterization of their solubilizing properties. The Hansen solubility parameters, derived from the theory of Hildebrand, provide a representation of the main molecular interactions in solution. Their applucation performance were tested in order to characterize emerfinf biosolvents and to study the solubilization of molecular and macromolecular solutes. In contrast, the COSMO-RS model combines quantum chemistry and statistical thermodynamics to predict molecular properties int the liquid state. The performance of this model was evaluated and used to account for the solubility phenomena of complex solutes such as nitrocellulose and fullerene-C60. With their ability to handle the two main mechanisms of solubilization (similarity and complementarity), the COSMO-RS descriptors were used to create new solubility parameters as simple as those of Hansen but more scientifically rigorous. This renewal of the solubility parameters is based on the consideration of the Lewis acide-base interactions and the new concept of COSMOmorphe for the calculation of dispersive interactions. These considerations enable the development of a green degreasing microemulsion whose efficiency is based on an unusual mechanism of degreasing-stripping.

The transdermal delivery route has become a popular alternative to more conventional routes, such as oral administration, but has not yet reached its full potential (Prausnitz & Langer, 2008:1261). Although the transdermal route proves to have several advantages over the conventional route, the greatest challenge is to overcome the effective barrier of the skin (Jepps et al., 2012:153). The permeation of the active pharmaceutical ingredient (API) through the skin is a complex, multi-step process and therefore predicting the permeability of the API is difficult (Jepps et al., 2012:153; Williams, 2003:30). Various approaches have been developed to overcome the skin barrier and it is recognised that the nature of the vehicle in which the API is applied plays a significant role in promoting transdermal delivery (Foldvari, 2000:417). It is important to consider the fate of the formulation ingredients and the API after application and how this changes the composition of the formulation on the skin when developing a vehicle for transdermal delivery (Lane et al., 2012:496; Otto et al., 2009:2). Wiechers (2012) proposed the Skin Delivery Gap (SDG) as an indicator for the permeability of an API. An API with a SDG < 1 will readily permeate the skin, whilst an SDG > 1 indicates a more complex delivery system is required. The partitioning of the API between the skin and the formulation is influenced by the formulation and by altering the formulation properties it is possible to manipulate the transdermal delivery of the API. The relative polarity index (RPI), based on the octanol-water partition coefficient (log P) of the stratum corneum, formulation and the API, was initially developed by Wiechers as a tool for developing formulations with an optimal polarity, to ensure the transdermal delivery of at least 50% of the API (Lane et al., 2012:498; Wiechers, 2008:94; Wiechers et al., 2004:174). The use of log P as an indicator of polarity was considered impractical by Hansen (2013) and acknowledged by both Wiechers and Abbott, who consequently developed the Formulating for Efficacy™ (FFE™) software which uses Hansen solubility parameters (HSP) instead of log P to indicate polarity (Hansen, 2013). The FFE™ calculates HSP distances, known as gaps, between the skin, API and the formulation to indicate the solubility of the different components in each other. A smaller HSP gap indicates a high solubility. The FFE™ enables the formulator to develop a formulation with a good balance between the active-formulation gap (AFG) and the skin-formulation gap (SFG) to ensure sufficient diffusion of the API into the skin. The FFE™ software was used to develop formulations containing 1.5% atropine as a model drug. Formulations of different polarity (optimised towards the stratum corneum, more hydrophilic and more lipophilic) were developed to determine the effect of the polarity of the formulation and the relevant HSP gaps on the transdermal delivery of the API. The same formulations were utilised for atropine sulphate to determine the effect the salt form has on the transdermal delivery of the API compared to the base compound. The log P and octanol-buffer partition coefficient (log D) of both atropine and atropine sulphate were determined. Log D is a more reliable indicator of distribution compared to log P, since, it considers the degree of ionisation of the API (Ashford, 2007:294). The log P and log D of atropine (0.22 and -1.26) and atropine sulphate (-1.32 and -1.23) both predicted poor skin penetration (Brown et al., 2005:177). The aqueous solubility of atropine (0.9 mg/ml) also predicted limited transdermal delivery, while the solubility of atropine in phosphate buffer solution (PBS pH 7.4) (5.8 mg/ml) indicated favourable permeation (Naik et al., 2000:321). The high degree of ionisation of the API (99.68 %), at pH 7.4, predicts only a small amount will penetrate the skin (Barry, 2007:576). The membrane release study confirmed the API was released from the different formulations and subsequently skin diffusion studies were conducted, followed by tape stripping after 12 h, to determine which formulation resulted in the highest transdermal delivery of the API. The atropine hydrophilic formulation released the highest percentage of API after 6 h (13.930%). This was explained by the low affinity the lipophilic atropine has towards the hydrophilic formulation (Otto et al., 2009:9). The highest percentage transdermal delivery (0.065%) was observed with the lipophilic formulation containing atropine. The higher SFG compared to the AFG of the lipophilic formulation initially predicted poor transdermal delivery, but when considering the HSP profile and molar volume of the different ingredients, it was observed the dimethyl isosorbide (DMI) penetrated and provided a desirable environment for the API in the skin. The residual formulation (containing less DMI and more polyethylene glycol 400 (PEG 8) and liquid paraffin) was less desirable for the API and was therefore forced out of the formulation (Abbott, 2012:219). Both these factors contributed to the high transdermal delivery of atropine from the lipophilic formulation. The atropine sulphate hydrophilic formulation had the highest percentage in the stratum corneum-epidermis (0.29 μg/ml) and the hydrophilic formulation of both atropine and atropine sulphate had the highest concentration in the epidermis-dermis (both 0.55 μg/ml). The hydrophilic formulations had the lowest driving force provided by the AFG and the only driving force for the API to leave the formulation was the concentration gradient. These formulations had the lowest transdermal delivery which indicates the API had not fully traversed through the skin after 12 h. According to Wiechers, a minimised SFG would indicate the formulation is optimised towards the stratum corneum and should essentially deliver the highest percentage of API through the skin. The results obtained are contrary to this belief and it is concluded that the total HSP profile and the molar volume of the formulation and the API should be considered when developing a formulation with optimal transdermal delivery rather than just the SFG. / MSc (Pharmaceutics), North-West University, Potchefstroom Campus, 2015

The transdermal delivery route has become a popular alternative to more conventional routes, such as oral administration, but has not yet reached its full potential (Prausnitz & Langer, 2008:1261). Although the transdermal route proves to have several advantages over the conventional route, the greatest challenge is to overcome the effective barrier of the skin (Jepps et al., 2012:153). The permeation of the active pharmaceutical ingredient (API) through the skin is a complex, multi-step process and therefore predicting the permeability of the API is difficult (Jepps et al., 2012:153; Williams, 2003:30). Various approaches have been developed to overcome the skin barrier and it is recognised that the nature of the vehicle in which the API is applied plays a significant role in promoting transdermal delivery (Foldvari, 2000:417). It is important to consider the fate of the formulation ingredients and the API after application and how this changes the composition of the formulation on the skin when developing a vehicle for transdermal delivery (Lane et al., 2012:496; Otto et al., 2009:2). Wiechers (2012) proposed the Skin Delivery Gap (SDG) as an indicator for the permeability of an API. An API with a SDG < 1 will readily permeate the skin, whilst an SDG > 1 indicates a more complex delivery system is required. The partitioning of the API between the skin and the formulation is influenced by the formulation and by altering the formulation properties it is possible to manipulate the transdermal delivery of the API. The relative polarity index (RPI), based on the octanol-water partition coefficient (log P) of the stratum corneum, formulation and the API, was initially developed by Wiechers as a tool for developing formulations with an optimal polarity, to ensure the transdermal delivery of at least 50% of the API (Lane et al., 2012:498; Wiechers, 2008:94; Wiechers et al., 2004:174). The use of log P as an indicator of polarity was considered impractical by Hansen (2013) and acknowledged by both Wiechers and Abbott, who consequently developed the Formulating for Efficacy™ (FFE™) software which uses Hansen solubility parameters (HSP) instead of log P to indicate polarity (Hansen, 2013). The FFE™ calculates HSP distances, known as gaps, between the skin, API and the formulation to indicate the solubility of the different components in each other. A smaller HSP gap indicates a high solubility. The FFE™ enables the formulator to develop a formulation with a good balance between the active-formulation gap (AFG) and the skin-formulation gap (SFG) to ensure sufficient diffusion of the API into the skin. The FFE™ software was used to develop formulations containing 1.5% atropine as a model drug. Formulations of different polarity (optimised towards the stratum corneum, more hydrophilic and more lipophilic) were developed to determine the effect of the polarity of the formulation and the relevant HSP gaps on the transdermal delivery of the API. The same formulations were utilised for atropine sulphate to determine the effect the salt form has on the transdermal delivery of the API compared to the base compound. The log P and octanol-buffer partition coefficient (log D) of both atropine and atropine sulphate were determined. Log D is a more reliable indicator of distribution compared to log P, since, it considers the degree of ionisation of the API (Ashford, 2007:294). The log P and log D of atropine (0.22 and -1.26) and atropine sulphate (-1.32 and -1.23) both predicted poor skin penetration (Brown et al., 2005:177). The aqueous solubility of atropine (0.9 mg/ml) also predicted limited transdermal delivery, while the solubility of atropine in phosphate buffer solution (PBS pH 7.4) (5.8 mg/ml) indicated favourable permeation (Naik et al., 2000:321). The high degree of ionisation of the API (99.68 %), at pH 7.4, predicts only a small amount will penetrate the skin (Barry, 2007:576). The membrane release study confirmed the API was released from the different formulations and subsequently skin diffusion studies were conducted, followed by tape stripping after 12 h, to determine which formulation resulted in the highest transdermal delivery of the API. The atropine hydrophilic formulation released the highest percentage of API after 6 h (13.930%). This was explained by the low affinity the lipophilic atropine has towards the hydrophilic formulation (Otto et al., 2009:9). The highest percentage transdermal delivery (0.065%) was observed with the lipophilic formulation containing atropine. The higher SFG compared to the AFG of the lipophilic formulation initially predicted poor transdermal delivery, but when considering the HSP profile and molar volume of the different ingredients, it was observed the dimethyl isosorbide (DMI) penetrated and provided a desirable environment for the API in the skin. The residual formulation (containing less DMI and more polyethylene glycol 400 (PEG 8) and liquid paraffin) was less desirable for the API and was therefore forced out of the formulation (Abbott, 2012:219). Both these factors contributed to the high transdermal delivery of atropine from the lipophilic formulation. The atropine sulphate hydrophilic formulation had the highest percentage in the stratum corneum-epidermis (0.29 μg/ml) and the hydrophilic formulation of both atropine and atropine sulphate had the highest concentration in the epidermis-dermis (both 0.55 μg/ml). The hydrophilic formulations had the lowest driving force provided by the AFG and the only driving force for the API to leave the formulation was the concentration gradient. These formulations had the lowest transdermal delivery which indicates the API had not fully traversed through the skin after 12 h. According to Wiechers, a minimised SFG would indicate the formulation is optimised towards the stratum corneum and should essentially deliver the highest percentage of API through the skin. The results obtained are contrary to this belief and it is concluded that the total HSP profile and the molar volume of the formulation and the API should be considered when developing a formulation with optimal transdermal delivery rather than just the SFG. / MSc (Pharmaceutics), North-West University, Potchefstroom Campus, 2015

This thesis is a study on how information about library closures are portrayed in media in four national British newspapers. The aim is to raise awareness that what is written in media usually consists of a frame around what is said. Also that the information that comes through is not always a depiction of reality but rather a reflection of it. Questions raised were: How are library closures being portrayed in media? What kind of functions in the articles can be seen as important for the library and it's future?The theories used are framing theory and Jochumsen, Rasmussen and Skot-Hansens the four space model of the public library from 2012. The method used was a conventional content analysis which resulted in four main themes that described the articles content in relation to the closure of libraries. The four main themes are Economy, Availability, Functions and Reactions of closures where the theme of Functions related well to the four space model. The results also show that choice of newspaper may have an impact on how users receive information about library closures.

Thesis--Copenhagen. / At head of title: P.P. Jørgensen.

Thesis (M.A.)--Brigham Young University. Dept. of English, 2008. / Includes bibliographical references (p. 42-46).

Thesis--Copenhagen. / At head of title: P.P. Jørgensen.

No description available.

O uso do bagaço de cana-de-açúcar, um subproduto da produção sucroalcooleira, ainda está hoje atrelado diretamente à produção de energia com sua queima nas usinas, um uso que é pouco nobre, considerando-se a grande diversidade de compostos químicos presentes neste tipo de material. A possibilidade de valorização desta matéria-prima lignocelulósica está ligada a realização de etapas de separação das principais frações de compostos, a celulose, as hemiceluloses e a lignina. Neste contexto, as deslignificações organossolve, etapa de remoção da lignina através da solubilização da mesma em soluções orgânicas, tem grande potencial de uso, visto que nestas pode-se recuperar tanto a polpa como o licor de polpação para posterior uso. Assim, verifica-se que a solubilidade da lignina é o fator que diferencia a utilização de um dado solvente orgânico em uma deslignificação organossolve. Desta maneira, pode-se utilizar o conceito de parâmetros de solubilidade para a escolha de um melhor solvente para o processo. Neste trabalho, verificou-se a relação entre a deslignificação organossolve e a distância e afinidade de um solvente com a esfera de solubilidade de Hansen para a lignina de bagaço de cana-de-açúcar. Verificou-se que os parâmetros de solubilidade de Hansen para a lignina verificados na literatura não apresentam boa correlação com os dados de deslignificação, porém, uma nova esfera de solubilidade foi desenvolvida, na qual verificou-se um coeficiente de determinação de 0,93856, em detrimento de um de 0,72074 para a esfera de solubilidade verificada na literatura. Concluiu-se que o modelo desenvolvido possuía como principal diferença com relação ao modelo obtido por Hansen e Björkman para a lignina, um parâmetro de solubilidade para interações intermoleculares polares (&delta;p) inferior e um parâmetro de solubilidade para a capacidade de realização de ligações de hidrogênio (&delta;h) bem superior, porém mantendo o mesmo parâmetro de solubilidade total (&delta;). Confirmou-se a relação entre a deslignificação e os valores de distância e de afinidade obtidos neste trabalho, com a realização de deslignificações usando misturas ternárias e quaternárias com solventes de baixo custo e/ou excedentes no mercado (etanol, glicerol e 2-butanol, além de água). Concluiu-se que apesar da esfera de solubilidade desenvolvida permitir melhor ajuste dos dados, não se pode afirmar que esta é com certeza a esfera real para a lignina. / The use of sugarcane bagasse, a by-product of sugar and ethanol production, is still linked today directly to energy production with its burning in power plants, a use which is not very noble, considering the great diversity of chemical compounds present in the lignocellulosic matrix. The possibility of better use of lignocellulosic feedstock is linked to steps of separation of their main fractions, cellulose, hemicelluloses and lignin. In this context, organosolv delignification, in which lignin is removed by the solubilization in organic solutions have great potential, since both pulps and the pulping liquor can be recovered for later use. Thus, since the solubility of lignin is the factor that differentiates the use of a given organic solvent in an organosolv delignification, the concept of solubility parameters can be used for the selection of the organic solvent. In this dissertation the relationship between the distance and the affinity of a solvent with the Hansen sphere of solubility for lignin from bagasse cane sugar and organosolv delignification were studied. It was found that the Hansen solubility parameters for lignin found in the literature do not present a good correlation with delignification data. Thus a new sphere of solubility was developed, with a determination coefficient of 0.93856, over a determination coefficient of 0.72074 for the sphere of solubility found in the literature. It was concluded that the main differences between the developed model and the model obtained by Hansen and Björkman for lignin were a lower solubility parameter for polar intermolecular interactions (&delta;p) and a higher solubility parameter for hydrogen bonds (&delta;h), however keeping the same total solubility parameter (&delta;). The relationship between delignification and the values of the distance and affinity obtained in this work were confirmed with the attainment of organosolv delignification using tertiary and quaternary mixtures of solvents with low cost and/or availability in the market (ethanol, glycerol and 2-butanol, in addition to water). It was concluded that although the developed solubility sphere allowed a better fit of the data, it cannot be stated with certainty that this is the real sphere for lignin.