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In the semiconductor industry, plasma etching processes are widely used. Process chamber parts that are located in the plasma etching system are also exposed to the harsh environmental conditions. Thus, parts located close to the process area are typically coated with yttria to increase service life, and thus process performance. However, such yttria coatings are usually porous, and thus can be attacked by fluorine containing plasma. In order to increase the lifetime of the components in the plasma etching system, this research project aimed to improve the protective yttria layer by reducing the porosity of the protective layer. Specifically, a design of experiment was employed in which the porosity was the target value. The main effects of the coating parameters and their interactions including the surface treatment before the coating process were determined. Furthermore, the bonding of the protective coating to the component to be protected, as well as the element distribution and the coating morphology were investigated. The results and their ramifications with respect to the envisaged application will be discussed.

In addition to the proper functional properties, the adhesive strength represents one of the key criteria for industrial use of thermally sprayed coatings. Since conventional thermal spraying processes are almost carried out exclusively in air atmosphere, this leads to the oxidation of the particles and of interfaces within the coatings. As a result, conventional thermally sprayed metallic and metal-ceramic coatings are characterized by heterogeneous microstructures with interlamellar oxide fringes at the interfaces between individual splats and also between the coating and the substrate. This has a decisive influence on the bond strength and on the wear and corrosion protection properties of thermally sprayed coatings. The aim of this study is to present the potentials of thermal spraying processes carried out in a mixture of monosiliane and an inert gas at ambient pressure as an alternative to the known vacuum spraying process in order to prevent oxidation during the coating process. Using the example of arcsprayed coatings, it is demonstrated that the extremely low oxygen partial pressure in the silane-doped medium leads to coatings free of oxide seams with a reduced porosity and substantially enhanced properties.

In this study, the thermal conductivity ( κ ) of Al–Cu eutectics were investigated by experimental and computational methods to shed light on the role of these compounds in thermal properties of Al–Cu connections in compound casting. Specifically, the nonequilibrium molecular dynamics (MD) method was utilized to simulate the lattice thermal conductivity ( κ l ) of six compositions of Al–Cu with 5–30 at.% Cu. To extend the results of the MD simulations to bulk materials, instead of using conventional linear extrapolation methods, a machine learning approach was developed for the dataset acquired from the MD simulations. The bootstrapping approach was utilized to find the most suitable method among the support vector machine (SVM) with polynomial and radial basis function (RBF) kernels and the random forest method. The results showed that the SVM model with RBF kernel performed the best, and thus was used to predict the bulk κ l . Subsequently, the chosen compositions were produced by induction casting and their electrical conductivities were measured via eddy current method for calculating the electronic contribution of κ using the Wiedemann–Franz law. Finally, the actual κ of the alloys were measured using the xenon flash method and the results were compared with the computational values. It was shown that the MD method is capable of successfully simulating the thermal conductivity of this system. In addition, the experimental results demonstrated that the κ of Al–Cu eutectics decreases almost linearly with formation of the Al2Cu phase due to increase in the Cu content. Overall, the current findings can be used to enhance the κ of cooling devices made via Al–Cu compound casting.

In the present study, tungsten inert gas wire and arc additive manufacturing was used to process an iron-based FeMnAlNi shape memory alloy. By a layer-by-layer method, a wall structure with a length of 60 mm and a height of 40 mm was generated. Bidirectional welding ensured grain growth parallel to the building direction. To maintain a nearly constant temperature–time path upon cooling, the structure was fully cooled after each weld to room temperature (298 K). With this approach, an anisotropic microstructure with a grain length of up to 8 mm (major axis) could be established. The grain morphology and formed phases were investigated by optical microscopy and scanning electron microscopy. The images revealed a difference in the orientation with respect to the building direction of the primarily formed γ grains along the grain boundaries and the secondarily formed γ grains in the heat-affected zones. Subgrains in the α matrix were observed also by scanning electron microscopy. With X-ray diffraction, the preferred orientation of the α grains with respect to the building direction was found to be near ⟨100⟩. Overall, an anisotropic polycrystalline material with a columnar texture could be produced, with a preferred grain orientation promising high values of transformation strains.

In this work, a bioresorbable Mg-ZKQX6000 (Mg-6Zn-0.6Zr-0.4Ag-0.2Ca (wt%)) alloy was severely plastically deformed via equal channel angular pressing (ECAP) according to three unique hybrid routes at low temperatures (200 °C to 125 °C). The roles of ECAP processing on microstructure, and ensuing mechanical properties and corrosion rates, are assessed. Microstructurally, ECAP induces a complex plethora of features, especially variations in grain sizes and precipitates' sizes, distributions, and morphologies for individual cases. Mechanically, ECAP generally refined grain size, resulting in ultra-high strength levels of about 400 MPa in ultimate tensile strength for several cases; however, deformation via ECAP of precipitates induced embrittlement and low elongation to failure levels. Corrosion testing, conducted in simulated bodily fluid at bodily pH levels to mimic conditions in the human body, revealed consistent corrosion rates across several techniques (mass loss, hydrogen evolution, and electrochemical impedance spectroscopy (EIS)), showing that severe plastic deformation deteriorates corrosion resistance for this material. In-situ corrosion monitoring explained that corrosion accelerated after ECAP due to the creation of heterogeneous, anodic shear zones, which exhibited dense regions of refined grains and fine precipitates. Suggestions for future design and thermomechanical processing of Mg alloys for bioresorbable orthopedic implants are provided.

Monthly to seasonal streamflow forecasts provide useful information for a range of water resource management and planning applications. This work focuses on improving such forecasts by considering the following two aspects: (1) state updating to force the models to match observations from the start of the forecast period, and (2) selection of a shorter calibration period that is more representative of the forecast period, compared to a longer calibration period traditionally used. The analysis is undertaken in the context of using streamflow forecasts for environmental flow water management of an open channel drainage network in southern Australia. Forecasts of monthly streamflow are obtained using a conceptual rainfall–runoff model combined with a post-processor error model for uncertainty analysis. This model set-up is applied to two catchments, one with stronger evidence of non-stationarity than the other. A range of metrics are used to assess different aspects of predictive performance, including reliability, sharpness, bias and accuracy. The results indicate that, for most scenarios and metrics, state updating improves predictive performance for both observed rainfall and forecast rainfall sources. Using the shorter calibration period also improves predictive performance, particularly for the catchment with stronger evidence of non-stationarity. The results highlight that a traditional approach of using a long calibration period can degrade predictive performance when there is evidence of non-stationarity. The techniques presented can form the basis for operational monthly streamflow forecasting systems and provide support for environmental decision-making.

Depending on the size and type defects of nickel-based alloy turbine blades two procedures are used mainly: cladding and high temperature brazing. The repair brazing of turbine blades is used to regenerate cracks and surface defects and is the focus of this work. In this contribution a two stage hybrid repair brazing process is presented which allows reducing the current process chain for repair brazing turbine blades. In the first stage of this process the filler metal (NiCrSi) then the hot gas corrosion protective coating (NiCoCrAlY) and finally the aluminium are applied in this order by atmospheric plasma spraying. In the second stage of this hybrid technology the applied coating system undergoes a heat treatment in which brazing and aluminising are combined. The temperature-time regime has an influence on the microstructure of the coating which is investigated in this work.

The effect of the size and volume fraction of Ti 3 N 4 particles in Ti-(50.3-51.5) at % Ni single crys- tals on their martensitic transformation temperatures and temperature hysteresis is studied. Aging at T = 673- 823 K leads to a nonmonotonic change in the martensitic transformation temperatures and temperature hyster- esis, which is related to a change in the Ni concentration in the matrix, the hardening of the high-temperature phase, a change in the elastic and surface energies generated upon the martensitic transformations, and the inter- nal stresses that appear because of the difference in the lattice parameters of the particles and the matrix. As a result of the high strength of the B 2 phase and the high elastic and surface energies that are generated upon the martensitic transformations due to the precipitation of particles of size d < 40 nm at an interparticle distance λ < 50 nm, the martensitic transformation temperatures decrease down to the suppression of the R - B 19' transi- tions upon cooling to 77 K. A thermodynamic description for the martensitic transformations in heterophase crystals is proposed, and an analogy between the martensitic transformations in heterophase Ti-Ni single crys- tals with nanoparticles of size d = 20-100 nm and those in single-phase Ti-Ni polycrystals with a grain size of 50-200 nm is found.

The Circumpolar Arctic Vegetation Map (CAVM) was used to analyze the distribution of NDVI and phytomass in the Arctic, providing data for understanding arctic vegetation patterns, assessing change, and calibrating models. The dominant trend in the analysis of Normalized Difference Vegetation Index (NDVI) was a decrease from south to north, correlating with bioclimate subzones and vegetation units. NDVI also decreased at higher elevations and with higher substrate pH. In the coldest bioclimate subzone, increased elevation was not correlated with decreased NDVI. In the warmest tundra bioclimate subzone, especially in Alaska, NDVI did not decrease with the first several hundred meters of elevation. NDVI in this subzone varied more by region than by elevation or substrate chemistry, and was lowest in recently glaciated areas such as the Canadian Shield. Phytomass (above-ground plant biomass) was calculated from NDVI using a relationship derived from ground clip-harvest data. Phytomass for the tundra bioclimate subzone was estimated at 2.5 × 1012 kg, with most of this in the warmest subzone, at the lowest elevations, and on acidic substrates.

We analyzed the relation between early winter distribution and density of female moose (Alces alces L.) and habitat heterogeneity in interior Alaska. We tested for effects of vegetation type, topography, distance to rivers and towns, occurrence and timing of fire, and landscape metrics. A spatial linear model was used to analyze effects of independent variables organized at multiple scales. Because densities of moose vary widely as a result of differences in management and other factors, a spatial response surface of the log of moose density was fit to remove large-scale effects. The analysis revealed that the densest populations of moose occurred closer to towns, at moderate elevations, near rivers, and in areas where fire occurred between 11 and 30 years ago. Furthermore, moose tended to occur in areas with large compact patches of varied habitat and avoided variable terrain and nonvegetated areas. Relationships of most variables with moose density occurred at or below 34 km2, suggesting that moose respond to environmental variables within a few kilometres of their location. The spatial model of density of moose developed in this study represents an important application for effective monitoring and management of moose in the boreal forest.

Zusammenfassung Zum Nachweis verschiedener Arten von Werkstoffinhomogenitaten am Verbundwerkstoff C/C–SiC wurde die Wirbelstromtechnik unter Anwendung einer C–Scan-Probe qualifiziert. Neben Oberflachenkerben und –rissen wurden Inhomogenitaten und Risse direkt unter der Werkstoffoberflache an kohlenstoffbeschichteten und oxidierten Proben untersucht. Die Ergebnisse zeigen, dass die Wirbelstromtechnik eine sensible Methode ist, um derartige Fehler in C/C–SiC Materialien aufzuzeigen.

There is an increasing demand for peptide-mimicking molecules to modulate the interactions between proteins of pharmaceutical and agrochemical interest and their target polypeptides. Unnatural L-alpha-amino acids differing from the 20 naturally proteinogenic amino acids only in their side chain are ideal for this purpose, but their chemical synthesis is complex. Here we describe a fermentation-based approach for biosynthesis of unnatural amino acids after re-engineering the cysteine-biosynthetic pathway in Escherichia coli. O-acetylation of serine, the committed step of the pathway, was released from feedback inhibition by mutating the serine acetyltransferase gene. Next, the naturally broad substrate specificity of O-acetylserine sulfhydrylase was exploited for the direct in vivo incorporation of an unnatural side chain in a semisynthetic fermentation process comparable to the production of beta-lactams. O-acetyl-L-serine extruded from the cells by way of the O-acetylserine efflux protein was amenable to further biotransformations.

An existing extensive database on the isothermal and thermomechanical fatigue behaviour of high-temperature titanium alloy EVII 834 and dispersoid-strengthened aluminum alloy X8019 in SiC particle-reinforced as well as unreinv conditions was used to evaluate both the adaptability of fracture mechanics approaches to TMF and the resulting predictive capabilities of determining material life by crack propagation consideration. Selection of the correct microstructural concepts was emphasised and these concepts were, then adjusted by using data from independent experiments in order to avoid any sort of fitting. It is shown that the cyclic /-integral (δJeff concept) is suitable to predict the cyclic lifetime for conditions where the total crack propagation rate is approximately identical to pure fatigue crack growth velocity. In the case that crack propagation is strongly affected by creep, the creep-fatigue damage parameter δCF introduced by Riedel can be successfully applied. If environmental effects are very pronounced, the accelerating influence of corrosion on fatigue crack propagation can no longer implicitly be taken into account in the fatigue crack growth law. Instead, a linear combination of the crack growth rate contributions from plain fatigue (determined in vacuum) and from environmental attack is assumed and found to yield a satisfactory prediction, if the relevant corrosion process is taken into account.

Differences in the summer insulative value of the zonal vegetation mat affect the depth of thaw along the Arctic bioclimate gradient. Toward the south, taller, denser plant canopies and thicker organic horizons counter the effects of warmer temperatures, so that there is little correspondence between active layer depths and summer air temperature. We examined the interactions between summer warmth, vegetation (biomass, Leaf Area Index, Normalized Difference Vegetation Index), soil (texture and pH), and thaw depths at 17 sites in three bioclimate subzones of the Arctic Slope and Seward Peninsula, Alaska. Total plant biomass in subzones C, D, and E averaged 421 g m � 2 , 503 g m � 2 , and 1178 g m � 2 respectively. Soil organic horizons averaged 4 cm in subzone C, 8 cm in subzone D, and 14 cm in subzone E. The average late-August thaw depths in subzones C, D, and E were 44 cm, 55 cm, and 47 cm respectively. Non-acidic soils in equivalent climates generally have shorter-stature sedge-dominated canopies and many frost boils, and consequently have thicker active layers than acidic soils. The trends reported here are useful for palaeo-ecological reconstructions and predictions of future ecosystem changes in the Low Arctic. Climate change will not lead to uniform thickening of the active layer, and could lead to shallower active layers in some presently dry areas due to paludification. Copyright  2003 John Wiley & Sons, Ltd.

During the next few decades the Arctic is expected to experience unprecedented changes in climate and resource development. All of these will potentially affect land use and vegetation cover. There is a need for a comprehensive and consistent circumpolar map of arctic vegetation that will be useful for modelling vegetation change in the circumpolar region. The Canadian arctic vegetation map is part of the Circumpolar Arctic Vegetation Mapping project (CAVM) which was initiated to fulfil this need. The CAVM is an effort by an international group of arctic vegetation scientists to create a map and GIS database of circumpolar vegetation at the 1:7 500 000 scale. The Canadian vegetation map and ultimate circumpolar map will be useful for the study of arctic vegetation, modelling vegetation change at the continental and circumpolar scale, interpreting patterns of wildlife distribution and migration, land management, and educational purposes. The mapping effort combines information on soils, bedrock and surfici...

A new false-colour-infrared image derived from biweekly 1993 and 1995 Advanced Very High Resolution Radiometer (AVHRR) data provides a snow-free and cloud-free base image for the interpretation of vegetation as part of a 1:7.5 M-scale Circumpolar Arctic Vegetation Map (CAVM). A maximumNDVI (Normalized Difference Vegetation Index) image prepared from the same data provides a circumpolar view of vegetation green-biomass density across the Arctic. This paper describes the remote sensing products, the environmental factors that control the principal vegetation patterns at this small scale, and the integrated geographic information-system (GIS) methods used in making the CAVM.

Magnesium alloys are currently being investigated for use as resorbable biomaterials. Various applications for magnesium based implant materials have already been presented. Currently, stents and structures that sustain diseased or narrowed vessels seem to be the most promising areas. This study focuses on the use of a magnesium fluoride (MgF2 ) coated magnesium neodymium based alloy (MgNd2 ) and its use as a postsurgery stent material to avoid proliferation in the sinus region. Simple cylindrical shaped specimens were sown to the sinus' mucosa of pigs and left in place for different periods of time to investigate the long-term corrosion resistance of the alloy and its coating during direct contact with physiological tissue. Investigations made within this study explicitly focused on the corrosive behavior of the alloy in the region of a physiological sinus. Thus, losses in mass and volume, and element analyses were considered to obtain information about the specimens' corrosion performance over time. Furthermore, micrographs support the alloy specific corrosion type analyses which focus on grain boundary effects. This study demonstrates the general in vivo applicability of fluoride coated MgNd2 . The progress of corrosion was determined to be adequate and homogeneous over a total period of 180 days.

Optical isotope shift measurements have been performed at the 244fAm fission isomers (T1/2=1 ms) with low target production rates of 10/s employing resonance ionization spectroscopy in a buffer gas cell. The isotope shift ratio IS244f,241/IS243,241 = 42.0(9) has been measured at the 500.02 nm transition. A change in the nuclear mean charge radius \(\delta \langle r^2 \rangle _{{\text{opt}}}^{{\text{224}}f,241}\) = 5.41(31) fm2 and an intrinsic quadrupole moment \(Q_{{\text{20}}}^{{\text{224}}f}\) = 34.4 eb have been deduced with the deformed Fermi model. The small difference of the nuclear parameter Λ244f,242f = 0.069(21) fm2 between the 244fAm and 242fAm fission isomers results in a change of the quadrupole moment \(\delta Q_{{\text{20}}}^{{\text{224}}f,242f}\) eb only and demonstrates the stability of the superdeformation in the second potential minimum if two neutrons are removed.

Ground and isomeric proton and alpha decay branches are reported for the new isotope ${}^{177}\mathrm{Tl},$ produced by bombarding a ${}^{102}\mathrm{Pd}$ target with a 370 MeV beam of ${}^{78}\mathrm{Kr}$ ions. The ground state is assigned as a $\ensuremath{\pi}{s}_{1/2}$ configuration and the high spin isomer is assigned as a $(\ensuremath{\pi}{h}_{11/2}{)}^{\ensuremath{-}1}$ configuration. The ground-state proton decay of ${}^{171}\mathrm{Au}$ has been identified for the first time, produced by bombarding a ${}^{96}\mathrm{Ru}$ target with ${}^{78}\mathrm{Kr}$ ions. The ${}^{171}\mathrm{Au}$ ground state is also assigned as a $\ensuremath{\pi}{s}_{1/2}$ configuration. Spectroscopic factors, masses, and proton separation energies are derived using these new proton decay measurements. New ground-state $\ensuremath{\alpha}$ decays for ${}^{169}\mathrm{Ir}$ and ${}^{173}\mathrm{Au}$ are also reported.

Recent Coulomb-activation experiments indicate the presence of a low-lying intermediate state depopulating the long-lived 180Ta isomer to the radioactive g.s. with considerable conquences on the effective halflife of 180Ta under s-process conditions. An ‘in-beam’ Coulomb-excitation experiment searching for the relevant transitions is reported using a 5.6% enriched 180Ta target and a particle-gamma coincidence setup consisting of five HPGe EUROBALL cluster modules covering about 10% of 4π solid angle and the NaI Crystal Ball filling the rest. Preliminary analysis indicates Coulomb excited levels in 180Ta around 700 and 1050 keV.

Die Verbesserung der endoskopischen Aufnahmetechnik macht heute eine endoskopische Inspektion der Cochlea moglich. Die Untersuchungstechnik erfolgte bisher uber eine intraoperative Cochleotomie im Rahmen von Cochleaimplantoperationen bei surden Patienten. Wunschenswert ware eine diagnostische Endoskopie des geschadigten, noch horenden Innenohrs. Die Ziele der vorliegenden Arbeit waren daher zum einen die Verfeinerung der Cochleoskopie am Saugetierohr und des weiteren, die Auswirkung der Ruptur des runden Fensters und das Eindringen des Endoskops in die Cochlea mit Hilfe der Summenaktionspotentiale zu untersuchen. Anhand von Untersuchungen der Schwellen des Summenaktionspotentials (SAP) am Meerschweinchen wissen wir, das die vorsichtige Offnung des runden Fensters zu keiner signifikanten SAP-Schwellenerhohung fuhrt; daher wurde das Endoskop durch das runde Fenster eingefuhrt. Als Versuchsmodell diente die Cochlea des Meerschweinchen (350–450 g). Die Tiere wurden mittels Ketanest (60 mg/kg) und Rompun (12 mg/kg) intramuskular in Narkose operiert. Das Monitoring der Narkosetiefe erfolgte an den tracheotomierten und beatmeten Tieren uber EKG und Pfotenreflex. Zur Darstellung des runden Fensters wurde ein dorsaler Zugangsweg unter Resektion der Bulla gewahlt. Das weitere Vordringen in Richtung rundes Fenster erfolgte hierbei uber ein per Mikromanipulator gesteuertes Endoskop (Durchmesser 0,29 mm mit 2000 Fasern; 0,7 mm mit 3000 Fasern; 0,89 mm mit 3000 Fasern). Die raumliche Lage konnte des weiteren uber ein Operationsmikroskop verfolgt werden. Dabei diente als Zustandskontrolle der Cochlea die Messung der SAP-Schwelle vor und wahrend wesentlicher Versuchsphasen. Die gewonnenen Ergebnisse zeigen hierbei, das eine Cochleoskopie an Ohren des Meerschweinchens ohne Beeintrachtigung der SAP-Schwellen moglich ist. Der Versuchsaufbau soll Baustein fur kunftige endoskopische In-vivo-Untersuchungen der Cochlea vom runden Fenster aus sein. Anhand der vorliegenden Resultate besteht die Hoffnung, das durch die weitere Miniaturisierung der Endoskope mit verbesserter Auflosung eine diagnostische Endoskopie der Cochlea durch die Tuba Eustachii oder uber einen Parazenteseschnitt durch das Trommelfell am Menschen moglich sein wird.

In recent times, an apparent increase in the frequency and intensity of blooms of cyanobacteria (blue-green algae) in the River Murray (Australia) has caused widespread concern. When present in large numbers, they can cause serious problems for domestic, industrial, agricultural and recreational users of water, as they can produce toxins and impart undesirable tastes and odours to water. It is important to understand the relationship between the incidence of algal populations and the prevailing environmental conditions in order to prevent algal blooms from occurring. In this paper, artificial neural networks (ANNs) are used to model the incidence of a specific genus of cyanobacteria ( Anabaena sp. ) in the River Murray at Morgan, with the dual objectives of forecasting algal concentrations to give prior warning of impending blooms and to identify the factors that affect the blooms of Anabaena . The model inputs include weekly values of turbidity, colour, temperature, flow and the concentrations of total nitrogen, as well as soluble and total phosphorus. The results obtained are very promising as the model was able to forecast most major variations in Anabaena concentrations (timing and magnitude) for an eight-year period two weeks in advance. A sensitivity analysis carried out on the model inputs indicated that all input variables are important, with no one variable being dominant.

Owing to their mechanical properties, metallic materials present a promising solution in the field of resorbable implants. The magnesium metabolism in humans differs depending on its introduction. The natural, oral administration of magnesium via, for example, food, essentially leads to an intracellular enrichment of Mg(2+) . In contrast, introducing magnesium-rich substances or implants into the tissue results in a different decomposition behavior. Here, exposing magnesium to artificial body electrolytes resulted in the formation of the following products: magnesium hydroxide, magnesium oxide, and magnesium chloride, as well as calcium and magnesium apatites. Moreover, it can be assumed that Mg(2+) , OH(-) ions, and gaseous hydrogen are also present and result from the reaction for magnesium in an aqueous environment. With the aid of physiological metabolic processes, the organism succeeds in either excreting the above mentioned products or integrating them into the natural metabolic process. Only a burst release of these products is to be considered a problem. A multitude of general tissue effects and responses from the Mg's degradation products is considered within this review, which is not targeting specific implant classes. Furthermore, common alloying elements of magnesium and their hazardous potential in vivo are taken into account.

The fission probability of 232Pa was measured as a function of the excitation energy in order to search for hyperdeformed (HD) transmission resonances using the (d,pf) transfer reaction on a radioactive 231Pa target. The experiment was performed at the Tandem accelerator of the Maier-Leibnitz Laboratory (MLL) at Garching using the 231Pa(d,pf) reaction at a bombarding energy of E=12 MeV and with an energy resolution of dE=5.5 keV. Two groups of transmission resonances have been observed at excitation energies of E=5.7 and 5.9 MeV. The fine structure of the resonance group at E=5.7 MeV could be interpreted as overlapping rotational bands with a rotational parameter characteristic to a HD nuclear shape. The fission barrier parameters of 232Pa have been determined by fitting TALYS 1.2 nuclear reaction code calculations to the overall structure of the fission probability. From the average level spacing of the J=4 states, the excitation energy of the ground state of the 3rd minimum has been deduced to be E(III)=5.05 MeV., Comment: 6 pages, 8 figures

Hair damage, caused by sunlight, and the possibility to protect hair against sunlight by means of cosmetic formulations was studied. For this, five UV-filters were tested: benzophenone-3 (UV-A/UV-B); benzophenone-4 (UV-A/UV-B); phenylbenzimidazole sulfonic acid (UV-B); butylmethoxydibenzoylmethane (UV-A); octyl dimethyl PABA (UV-B). The stability of the UV-filters was tested as pure substances as well as in two cosmetic formulations: a setting lotion and a shine spray. The degree of decolouration and stress strain behaviour were determined. The benzophenones had the best protection ability both on colour and on morphology. Stability data and UV-spectra are discussed Les effets nocifs de la lumiere solaire sur les cheveux, ainsi que les possibilites de proteger ces derniers des rayons solaires avec des formules cosmetiques ont ete etudies. A cet effet, cinq filtres d'UV ont ete testes: benzophenone-3 (UV-A/UV-B); benzophenone-4 (UV-A/UV-B); phenylbenzimidazole sulfonique acide (UV-B); butylmethoxydibenzoylmethane (UV-A); octyl dimethyl PABA (UV-B). La stabilite des filtres d'UV a ete testee, d'une part en tant que substances a l'etat pur et d'autre part integres dans deux formules cosmetiques: une lotion de mise en plis et un spray brillance. On a determine le degre de decoloration et la resistance a la tension. Resultat: les benzophenones ont la meilleure capacite de protection de la couleur et de la structure du cheveu. La stabilite des resultats et le spectre des UVs sont egalement discutes