Diploma thesis studies the layers created by laser cladding and method of testing abrasion resistance of these layers using the method of dynamic shock impactor. In the theoretical part describes laser technologies and their applications, hardness testing and methods of testing of coatings. Proposed by the mechanical testing of the selected materials were carried out and evaluated in the experimental part. The conclusion summarizes final results of the experiment.

Pour évaluer l'impact d’un rejet accidentel ou chronique de polluants dans les écosystèmes, il est important d’étudier le dépôt sec des aérosols en milieu rural. Le manque de données expérimentales en milieu rural sur la vitesse de dépôt sec des particules ayant une taille inférieure à 1 μm conduit à des incertitudes au vu des modèles et de leurs différences, qui vont jusqu’à dépasser un ordre de grandeur. Le but de cette étude est de développer une mesure directe de la vitesse de dépôt sec des aérosols (Vd), notamment en utilisant un impacteur à basse pression (Electrical Low Pressure Impactor, ELPI, DEKATI), à travers des mesures expérimentales in situ. L’originalité de la méthode est le calcul des flux de dépôt par corrélation turbulente. Les vitesses de dépôt sec ont été obtenues pour des aérosols atmosphériques de tailles comprises entre 7 nm et 2 μm, sur un terrain plat dans le sud-ouest de la France, sous différentes conditions atmosphériques, ainsi que sur différents couverts (maïs, herbe, sol nu). Vd est analysée en fonction du diamètre des particules et l’impact des conditions micro météorologiques est étudié. / To evaluate the impact of accidental or chronic pollutant releases on ecosystems, we must study the dry deposition of aerosols in rural areas. The lack of experimental data on the dry deposition velocity of particle sizes below 1 μm over rural environments leads to uncertainties regarding models and differences between them, which exceed one order of magnitude. The aim of thisstudy is to develop a method, especially using an Electrical Low Pressure Impactor (Outdoor ELPI, DEKATI) to determine aerosol dry deposition velocities (Vd) over rural areas through experimental measurements. This method is based on eddy covariance flux calculation and spectral analysis correction. Dry deposition velocities were obtained for atmospheric aerosols sizing from 7 nm to2 μm, in the South-West of France on a flat terrain under varied meteorological conditions andvaried substrates (maize, grass and earth). Vd was analysed as a function of the particle diameters, and the impact of micrometeorological parameters was studied.

Spray Polyurethane Foam insulation (SPF) kits are currently being marketed and sold to do-it-yourselfers to meet various insulating needs. Like commercial SPF systems, the primary health concern with SPF kits is user overexposure to the isocyanates during product application. The potential health risk associated with SPF applications is driven by several factors including (but not limited to): the toxicity of isocyanates; the potentially high exposure intensity; the quantity of isocyanates used in the process; the enclosed nature of the environment in which the product could be applied; the potentially high exposure duration/frequency; and the limited availability of control measures to reduce agent intensity (e.g., personal protective equipment, dilution ventilation). To better understand the potential hazards associated with the use of SPF kits, the current study was designed to provide an initial characterization of user exposure to airborne particulate during the application process. Specifically, the study would aim to answer the following: * What is the particle size distribution of the aerosol a SPF kit user is exposed to during application? * What is the airborne particle mass concentration a SPF kit user is exposed to during application? To answer these questions, a single commercially available SPF kit was selected for use and a mock residential environment was constructed to support repeated applications of SPF. Size-selective and total dust air sampling were conducted during the applications to determine the particle size distribution and mass concentration of aerosols generated by the selected kit. The particle size distributions developed from the size selective sampling results showed the presence of airborne particulate capable of penetration to the gas exchange regions of the respiratory tract. The average mass median diameter and geometric standard deviation of the particle size distributions were 4.6 µm and 2.7 respectively. The total dust sampling results showed mean airborne concentrations of 10.40 mg/m3. Based on the sampling results the study, personal air monitoring is needed to assess the degree of user exposure to methylene diphenyl diisocyanate (MDI) and to provide information for the selection of exposure control methods.

Transport of solid particles in a slit virtual impactor has been analyzed using visualization techniques. Particle trajectories were observed using laser-induced fluorescence of monodisperse particles seeded in the virtual impactor flow. It was observed from these trajectories that for smaller inertia particles essentially followed the flow streamlines, whereas higher inertia particles tend to deflect from their initial streamlines. These transport characteristics were used to determine particle collection efficiency curves, and the percentage of defect particle transmission, particles transmitted to the major flow that are well beyond the experimentally determined 50% cutoff. Defect percentages were found to be in good agreement with those based on a local stokes number approach, an analytical model using a converging flow velocity profile. It was hypothesized that these defects occur by virtue of larger particles passing through the near wall flow region and consequently transported to the major flow. The trajectories of such defect occurrences clearly show that these particles originated in the near wall region. Performance at higher mass loadings was evaluated using a background dust matrix generated by a turntable aerosol generator. At high mass loadings, clogging of the slit led to the deterioration of the impactor's performance. The time taken to clog the silt was estimated by modeling the slit edge as a single filter fiber of rectangular cross section with the primary mechanism of filtration being interception and was found to be in good agreement with the experimental data. Elimination of defect transmission and clogging would be possible by the provision of a sheath airflow, which ensures that the near wall regions are free of particles.

Transport of solid particles in a slit virtual impactor has been analyzed using visualization techniques. Particle trajectories were observed using laser-induced fluorescence of monodisperse particles seeded in the virtual impactor flow. It was observed from these trajectories that for smaller inertia particles essentially followed the flow streamlines, whereas higher inertia particles tend to deflect from their initial streamlines. These transport characteristics were used to determine particle collection efficiency curves, and the percentage of defect particle transmission, particles transmitted to the major flow that are well beyond the experimentally determined 50% cutoff. Defect percentages were found to be in good agreement with those based on a local stokes number approach, an analytical model using a converging flow velocity profile. It was hypothesized that these defects occur by virtue of larger particles passing through the near wall flow region and consequently transported to the major flow. The trajectories of such defect occurrences clearly show that these particles originated in the near wall region. Performance at higher mass loadings was evaluated using a background dust matrix generated by a turntable aerosol generator. At high mass loadings, clogging of the slit led to the deterioration of the impactor's performance. The time taken to clog the silt was estimated by modeling the slit edge as a single filter fiber of rectangular cross section with the primary mechanism of filtration being interception and was found to be in good agreement with the experimental data. Elimination of defect transmission and clogging would be possible by the provision of a sheath airflow, which ensures that the near wall regions are free of particles.

Today, orally inhaled drugs found on the market suffer from variable and discontinuous pulmonary drug release which lowers efficacy and patience compliance. This is usually a consequence of the poor understanding of the interaction and dissolution behavior of drug particles in the lung environment. Thus, the aim of this project was to investigate the effect of the dissolution medium on dissolution profiles for the well-known orally inhaled drug budesonide (BD) and fluticasone propionate (FP), in order to assess the importance of a proper selection of dissolution media for in vitro dissolution methods. In order to achieve this a modified Andersen Cascade Impactor was used to simulate deposition of particles onto filters. The dissolution was measured using a Transwell set up with polycarbonate membranes that can hold the filters with the deposited drug on it. Different media were prepared, from simple to more biorelevant. The samples taken during the dissolution experiments were analyzed quantitatively using UPLC-UV and the experimental data was processed by fitting to the Weibull function. The aim of this project was successfully achieved and the dissolution media that worked best for both BD and FP was PBS with the addition of 0.5% SDS. On the other hand, the dissolution media that performed the least for both BD and FP was the simulated lung fluid (SLF) with presence of 0.02% (w/v) DPPC. This may be due to the fact that DPPC forms liposomal aggregates which probably results in the media becoming more viscous and hence the dissolution time becomes slower.

The design and performance evaluation of in-duct, isokinetic samplers capable of testing flat sheet, nuclear-grade High Efficiency Particulate Air (HEPA) filters simultaneously with a radial filter testing system is discussed in this study. Evaluations within this study utilize challenge aerosols of varying particle diameters and masses such as hydrated alumina, Arizona test dust, and flame-generated acetylene soot. Accumulated mass and pressure drop for each in-duct sampler is correlated to the full-scale radial filter accumulated mass from initial to 10 in w. c. of loading. SEM imaging of samples at 25%, 50%, 75% and 100% loading verifies particle sizes with instrumentation used, revealing filter clogging resulting from particle impaction and interception. The U.S Department of Energy requires prototype nuclear-grade HEPA filters to be qualified under ASME AG-1 standards. The data obtained can be used to determine baseline performance characteristics on pleated radial filter medium for increased loading integrity and lifecycle endurance.

Surface energetics play a key role in the delivery of a dry powder inhaler formulation into the lungs, as there must be a sufficient balance of adhesive and cohesive forces to allow optimal lung delivery. In this study, measuring the surface energies of a set of single drug and carrier (budesonide or theophylline with either mannitol or lactose) with different levels of surfactant using Inverse Gas Chromatography, and comparing them to their lung deposition performance using a Next Generation Impactor established a relationship between the two. A 1:10 mixing ratio of budesonide with either carrier was found to have the highest FPF. Coating the carriers with 0.05% sodium lauryl sulphate resulted in a further increase in the FPF when using either budesonide or theophylline as the API, and the same results were seen when a sonocrystallised version of the API was substituted for the micronised form. The calculated IGC values then showed that the highest performing formulations had the lowest dispersive energy and total free surface energy. Furthermore, a trend was observed in the work of adhesion (Wa) and work of cohesion (Wc) for each set of formulations depending on which API was chosen, where for the less polar drug (budesonide) a higher Wa/Wc ratio was associated with the highest formulation performance, and for the more polar drug (theophylline) a smaller Wa/Wc ratio was associated with the highest formulation performance, enabling the estimation of lung performance for a set of single drug and carrier using their surface energy data. / Kuwait’s government and the Ministry of Health of Kuwait

This thesis is based around examination of three mainstream inhaled drugs Formoterol, Budesonide and Beclomethasone for treatment of asthma and COPD. The areas investigated are these which have been raised in reports and studies, where there are concern, for drug use and assessment of their use. In reporting this work the literature study sets out a brief summary of the background and anatomy and physiology of the respiratory system and then discuses the mechanism of drug deposition in the lung, as well as the methods of studying deposition and pulmonary delivery devices. This section includes the basis of asthma and COPD and its treatment. In addition, a short section is presented on the role of the pharmacist in improving asthma and COPD patient's care. Therefore the thesis is divided into 3 parts based around formoterol, budesonide and beclomethasone. In the first case the research determines the in-vitro performance of formoterol and budesonide in combination therapy. In the initial stage a new rapid, robust and sensitive HPLC method was developed and validated for the simultaneous assay of formoterol and the two epimers of budesonide which are pharmacologically active. In the second section, the purpose was to evaluate the aerodynamic characteristics for a combination of formoterol and the two epimers of budesonide at inhalation flow rates of 28.3 and 60 L/min. The aerodynamic characteristics of the emitted dose were measured by an Anderson cascade impactor (ACI) and the next generation cascade impactor (NGI). In all aerodynamic characterisations, the differences between flow rates 28.3 and 60 were statistically significant in formoterol, budesonide R and budesonide S, while the differences between ACI and NGI at 60 were not statistically significant. Spacers are commonly used especially for paediatric and elderly patients. However, there is considerable discussion about their use and operation. In addition, the introduction of the HFAs propellants has led to many changes in the drug formulation characteristics. The purpose of the last section is to examine t h e performance of different types of spacers with different beclomethasone pMDIs. Also, it was to examine the hypothesis of whether the result of a specific spacer with a given drug/ brand name can be extrapolated to other pMDIs or brand names for the same drug. The results show that there are different effects on aerodynamic characterisation and there are significant differences in the amount of drug available for inhalation when different spacers are used as inhalation aids. Thus, the study shows that the result from experiments with a combination of a spacer and a device cannot be extrapolated to other combination.

Drywall, a popular building material made of gypsum based plaster sandwiched between two thick sheets of paper is used for building interior walls, is speedier alternative to traditional plaster, decreasing time and labor for construction. Importance of drywall increased with the demand for drywall after nine hurricanes hit Florida in 2004-05 and widespread damage caused in the Gulf Coast after Katrina in 2005. This study has two parts. First part presents an analysis of metals like strontium for the identification of Chinese drywall, and a comparison of strontium concentrations of American drywall and Chinese drywall using XRF (X-Ray Fluorescence) analysis with the Innov-X XRF analyzer. The second part presents an analysis of metal exposure during cutting and installation of drywall using 8stage Cascade impactor. The work space concentration of, different metals is analyzed using XRF analysis and particulate matter within various size ranges, were calculated and their effects are studied.