Ce travail étudie l'influence des propriétés de surface sur l'écoulement limite de liquides<br />simples aux parois solides, à l'aide d'expériences de nanorhéologie réalisées avec<br />une machine à forces de surfaces dynamique. Nous mettons d'abord en évidence l'influence<br />du mouillage sur la condition limite hydrodynamique intrinsèque s'appliquant sur<br />des surfaces lisses à l'échelle nanométrique. Nous montrons en revanche que le glissement<br />interfacial ne dépend pas de la viscosité du liquide. Nous étudions ensuite l'écoulement<br />limite et la friction sur des interfaces complexes d'intérêt biologique solide/bicouche de<br />phospholipides/eau. Enfin nous étudions l'écoulement de mélanges eau-glycérol sur des<br />surfaces texturées et superhydrophobes. Nous mesurons à distance les propriétés élastiques<br />de ces surfaces dues aux poches de gaz piégées. Nous montrons que contrairement<br />à une idée répandue, ces poches de gaz ne sont pas toujours lubrifiantes et peuvent<br />augmenter significativement la friction interfaciale.

本研究以2000至2012年台灣地區26間人壽保險公司的不平衡縱橫資料，運用網絡隨機邊界分析法將壽險業的生產過程分為行銷與投資兩階段進行效率評估，並利用估計結果計算規模彈性與成本彈性探討台灣壽險業的生產特性，附帶分析跨期技術變動率，最後比較不同分組的壽險公司間經營效率是否存在差異。 實證結果發現壽險公司在行銷活動過程投入較少的內勤員工與較多的固定資產，在投資階段則相反，投入較多的內勤員工與較少的固定資產，與壽險公司實際運作情況相符；此外，投資階段的效率優於第一階段的行銷效率。整體台灣壽險業受到2008年金融風暴影響導致經營效率下降，國內壽險公司在經營效率上優於外商壽險分公司，金控壽險公司生產技術效率優於非金控壽險公司，1993年後成立的新壽險公司生產技術效率平均優於傳統舊壽險公司。 / This paper uses the copula-based network SFA model developed by Huang et al. (2013) to estimate the technical efficiency of Taiwan’s life insurance companies over the period 2000-2012. Under this framework, life insurance companies produce premium income as intermediate product which is one of input factors to produce investment income. The empirical analysis concluded: (a) life insurers use little internal staff in first stage, (b) domestic life insurers have both high technical efficiency and cost efficiency in comparison with foreign life insurers, (c) financial holding life insurers have greater technical efficiency than those of not from financial holding insurers, and (d) new life insurers have higher technical efficiency than old life insurers.

The structure and dynamics of the smectic-A liquid crystal 8CB (4 cyano-4 octylbiphenyl) when sheared and confined to mesoscale gaps (with crossed cylindrical geometry and mica confining surfaces) were studied using a Surface Forces Apparatus (SFA). Triangular shear patterns with frequencies of 0.01, 0.1, 1.0 and 10 Hz, and amplitudes of 62.5 nm, 625 nm and 6.25 m were applied to samples at gap sizes of 0.5 and 5.0 m. The study was performed at room temperature (20.5C) and at two higher temperatures (22C and 27C). In order to minimize the thermal fluctuations within the test chamber and hence to allow for the rapid re-initialization of test runs, the SFA was modified to allow for quick, precise and remote control of the confining surfaces. The procedure maximized the number of tests that could be undertaken with a single pair of surfaces so that a single gap geometry could be maintained for the duration of the test run. In order to run the SFA remotely, scripts written with a commercial software package, LabVIEW, were used to control of the SFA components, its FECO-monitoring camera and all its peripheral electronic equipment as well. Samples were agitated to disrupt any shear-induced liquid crystal domain alignment from previous testing following each shear test, and methodologies were developed to ascertain the extent of confinement quickly and remotely following agitation. Separate methods were developed for gap sizes at each extreme of the mesoscale regime, where the transition from bulklike structure and dynamics to nano-confinement occurs (between 1 and 10 microns for smectic-A 8CB). The results revealed that the greater amplitude-gap aspect ratio and surface-to-domain contact associated with smaller gaps facilitated reorientation of the domains in the shear direction. Evidence was also presented of domains at the higher end or outside of the mesoscale regime that, while straining and accreting, were unable to reorient and thereby led to an overall increase of viscoelastic response. The effective viscosity was found to obey a simple power law with respect to shear rate, , and the flow behaviour indices, n, slightly in excess of unity indicate shear thickening occurs with large enough shear amplitude, and that the viscosity reached a plateau near unity over shear rates of 0.005 to 500 s-1 within the mesoscale regime. Different K and n values were observed depending on the shear amplitude used. Unlike bulk smectic 8CB, whose domains do not align well in the shear direction with large shear-strain amplitude, at mesoscale levels of confinement large amplitude shearing (up to 12.5 shear strain amplitude) was found to be very effective at aligning domains. In general domain reorientation is found to be much more rapid within the mesoscale regime than has been reported in bulk. Aggressive shearing was found to result in a complete drop in viscoelastic response within seconds, while gentler shearing is found to produce a very gradual increase that persists for more than six hours, with individual shear periods exhibiting frequent and significant deviations from the expected smooth shear path that may be a product of discrete domain reorientations. From these findings, certain traits of the smectic 8CB domain structures under mesoscale confinement were deduced, including how they respond to shear depending on the level of confinement, and how their reorientation due to shear varies not only with shear rate but also independently with shear amplitude. An equation describing the viscosity change as a function of both shear rate and shear amplitude is proposed. The shear amplitude dependence introduces the notion of shearing beyond the proposed smectic 8CB “viscoelastic limit”, which was shown to exhibit behaviour in accordance with Large Amplitude Oscillatory Shear (LAOS) techniques developed for Fourier Transform rheology. The findings provided an understanding of the behavioural changes that occur as one reduces the level of confinement of smectic materials from bulk to nanoconfinement.

It is widely known that surfaces play an important role in numerous biological processes and technological applications. Thus, being able to modify surface properties provides an opportunity to control many phenomena occurring at interfaces. One way of controlling surface properties is to adsorb a polymer film onto the surface, for example through layer-by-layer (LbL) deposition of polyelectrolytes. This simple but versatile technique enables various polymers, proteins, colloidal particles etc. to be incorporated into the film, resulting in a multifunctional coating. Due to recent legislations and a consumer demand for more environmentally friendly products, we have chosen to use natural polymers (biopolymers) from renewable resources. The focus of this thesis has been on the adsorption of biopolymers and their layer-by-layer formation at solid-liquid interfaces; these processes have been studied by a wide range of techniques. The main method was the quartz crystal microbalance with dissipation monitoring (QCM-D), which measures the adsorbed mass, including trapped solvent and the viscoelastic properties of an adsorbed film. This technique was often complemented with an optical method, such as ellipsometry or dual polarization interferometry (DPI), which provided information about the “dry” polymer or protein adsorbed mass. From this combination, the solvent content and density of the layers was evaluated. In addition, the surface force apparatus (SFA), X-ray photoelectron spectroscopy (XPS), total internal reflection fluorescence (TIRF), and fluorescence resonance energy transfer (FRET) were utilized, providing further information about the film structure, chemical composition, and polymer inter-layer diffusion. Adsorption studies of the glycoprotein mucin, which has a key role in the mucousal function, showed that despite the net negative charge of mucin, it adsorbed on negatively charged substrates. The adsorbed layer was highly hydrated and the segment density on the substrate was low. We showed the importance of characterizing the mucin used, since differences in purity, such as the presence of albumin, gave rise to different adsorption behaviours in terms of both adsorbed amount and structure. The adsorbed mucin layer was to a large extent desorbed upon exposure to the anionic surfactant sodium dodecyl sulfate (SDS). In order to prevent desorption, we demonstrated that a protective layer of the cationic polysaccharide chitosan could be adsorbed onto the mucin layer and that the mucin-chitosan complexes resisted the desorption normally induced by association with SDS. Moreover, the association between chitosan and SDS was examined at the solid-liquid interface, in the bulk, and at the air-water interface. In all these environments chitosan-SDS complexes were formed and a net charge reversal of the complexes from positive to negative was observed when the concentration of SDS was increased. Furthermore, the LbL deposition method could be used to form a multilayer-like film by alternate adsorption of mucin and chitosan on silica substrates. The LbL technique was also applied to two proteins, lysozyme and β-casein with the aim of building a multilayer film consisting entirely of proteins. These proteins formed complexes at the solid-liquid interface, resulting in a proteinaceous layer, but the build-up was highly irregular with an increase in adsorbed amount per protein deposition cycle that was far less than a monolayer.Continuing with chitosan, known to have antibacterial properties we assembled multilayers with an anti-adhesive biopolymer, heparin, to evaluate the potential of this system as a coating for medical implants. Multilayers were assembled under various solution deposition conditions and the film structure and dynamics were studied in detail. The chitosan-heparin film was highly hydrated, in the range 60-80 wt-% depending on the deposition conditions. The adsorbed amount and thickness of the film increased exponential-like with the number of deposition steps, which was explained by inter-diffusion of chitosan molecules in the film during the build-up. In a novel approach, we used the distant dependent FRET technique to prove the inter-layer diffusion of fluorescent-labelled chitosan molecules within the film. The diffusion coefficient was insignificantly dependent on the deposition pH and ionic strength, and hence on the film structure. With the use of a pH sensitive dye buried under seven chitosan-heparin bilayers, we showed that the dye remained highly sensitive to the charge of the outermost layer. From complementary QCM-D data, we suggested that an increase in the energy dissipation does not necessarily indicate that the layer structure becomes less rigid. / Det är välkänt att ytor spelar en viktig roll i många biologiska processer och tekniska tillämpningar. Att kunna modifiera en ytas egenskaper ger därför en möjlighet att kunna kontrollera många fenomen som sker på ytor. Ett sätt att kontrollera ytegenskaperna är genom att adsorbera en polymerfilm på ytan, till exempel genom att växelvis adsorbera olika polyelektrolyter (LbL-teknik). Denna enkla men mångsidiga teknik möjliggör att många olika material kan införlivas i filmen, vilket resulterar i en multifunktionell beläggning. På grund av dagens lagstiftning och konsumenters ökade efterfrågan på miljövänliga material beslutade vi oss för att använda biologiska polymerer (biopolymerer) i detta projekt. Fokus i den här avhandlingen har varit på adsorption av biopolymerer och deras LbL-formation på gränsytan vätska-fast fas, där adsorptionsförloppet och det adsorberade skiktet bestående av biopolymerer studerats med en mängd olika tekniker. Huvudtekniken var kvartskristallmikrovåg med energidissipations-registrering (QCM-D), som mäter massan inklusive inkorporerat vatten, samt de viskoelastiska egenskaperna hos ett adsorberat skikt. Som komplement till denna teknik användes ofta optiska metoder, till exempel ellipsometri och ”dubbel polarisationsinterferometri (DPI)”, två tekniker som endast mäter massan av de adsorberade biopolymererna. Genom denna kombination av metoder kunde massan av inkorporerat vatten i filmen och filmens densitet bestämmas. Dessutom användes ytkraftsapparaten (SFA), röntgenfotoelektronspektrometri (XPS), och fluorescens-spektroskopiteknikerna TIRF och FRET i några undersökningar för att erhålla information om skiktens struktur, kemiska sammansättning och polymerernas diffusion inom skiktet.Adsorptionsstudier av glycoproteinet mucin, som har en central roll i funktionen av slemhinnan, avslöjade att trots att mucinet har en negativ nettoladdning adsorberade det ändå på negativt laddade substrat. Det adsorberade lagret var väldigt hydratiserat och hade en låg andel mucin i direkt kontakt med ytan. Vi påvisade vikten av att noga undersöka mucinet som användes, eftersom olika renhet, till exempel i form av förekomsten av albumin gav upphov till olika adsorptionsbeteende gällande både adsorberad mängd och struktur. En stor andel av det adsorberade mucinlagret desorberade när det exponerades för den anjoniska tensiden natriumdodecylsulfat, SDS. Vi visade att ett skyddande lager av den katjoniska polysackariden chitosan kunde adsorberas på mucinet och att mucin-chitosan-komplexen inte desorberade när SDS tillsattes. Därtill studerades växelverkan mellan chitosan och SDS på gränsytan vätska-fast fas, i bulken och på luft-vattengränsytan. Komplex av chitosan-SDS bildades i samtliga miljöer och en nettoladdningsomsvängning från positiv till negativ observerades när koncentrationen av SDS ökades.Vidare kunde LbL-tekniken nyttjas för att skapa ett multilagerlikt skikt genom att alternerande adsorbera mucin och chitosan på kiseldioxidsubstrat. Denna teknik användes även med två proteiner, lysozym och β-kasein, med målet att skapa ett multilager bestående av endast proteiner. Dessa proteiner bildade komplex på gränsytan vätska-fast fas i form av ett blandat proteinlager, men uppbyggnaden var väldigt oregelbunden med en ökning i adsorberad mängd per proteindeponeringscykel som var avsevärt mindre än ett monolager.Inom området för biomaterial utgör de antibakteriella och antihäftande egenskaperna hos chitosan respektive heparin en lovande blandning för beläggningar av medicinska implantat. Baserat på detta konstruerade vi multilagerfilmer av chitosan och heparin med olika deponeringslösningar och undersökte dynamiken och filmens struktur i detalj. Chitosan-heparin-filmen var starkt hydratiserad, bestående av cirka 60-80 vikt-% vatten beroende på deponeringsbetingelserna. Den adsorberade mängden och tjockleken på filmen ökade nästan exponentiellt med antal deponeringar, vilket förklarades med chitosanets förmåga att diffundera genom filmen under uppbyggnaden. Med ett nytt angreppssätt använde vi FRET för att bevisa diffusionen av fluorescerande färgmärkt chitosan i filmen under uppbyggnaden. Diffusionskoefficienten var i princip oberoende av pH och jonstyrka under deponeringen och följaktligen av filmens struktur. Genom att använda ett pH-känsligt färgämne begravt under sju biskikt av chitosan-heparin visade vi att färgämnet i hög grad påverkades av laddningen på det yttersta lagret. Från QCM-D-data lade vi fram teorin om att en ökning av energidissipationen för ett lager inte nödvändigtvis indikerar att lagrets struktur har blivit mindre styvt. / QC 20100729

The purpose of this thesis is to clarify the reasons and consequences of failed implementations and poor adoption of CRM / SFA tools in sales teams, that have been recorded in recent years. Almost 70% of initiatives to introduce new technologies for sales teams have failed in the return on investments. The goal of the thesis is to create requirements for a new CRM / SFA, which will support salesmen and sales teams in a better way. It describes the way the sales team work, it describes business cases and determinates its key activities. Using perceived usefulness, I create a set of system requirements for CRM / SFA tool, which will support salesmen and improve their sales performance.

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