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Knowledge of protein structures is necessary to clarify their structure-function relationships. Haloalkane dehalogenases are microbial enzymes that catalyze the hydrolysis of carbon-halogen in the halogenated hydrocarbons. Based on their properties these enzymes are able to degrade halogenated compounds. As the environment is burdened by a lot of different pollutants, biodegradation is a necessary step to improve the quality of environment. Haloalkane dehalogenases can be used as biosensors since they can detect contamination by halogenated compounds. This thesis is focused on crystallization of the model protein lysozyme and haloalkane dehalogenase DpcA isolated from the organism Psychrobacter cryohalolentis K5. The aim of this work was to prepare crystals suitable for X-ray diffraction analysis. After verification of protein?s purity, both proteins were crystallized by the use of basic and advanced crystallization methods. Single crystals of suitable size and quality for X-ray diffraction analysis were obtained and diffraction data were used to solve the 3D atomic structure of the DpcA. Since haloalkane dehalogenases have a low activity for halogenated substrates, the main aim of protein engineering is to increase their activity so thus further research is focused on modification of substrate specificity.

Recently, there has been growing interest on the behaviour of unbound granular material in road base layers. Researchers have studied that the design of a new pavement and prediction of service life need proper characterization of unbound granular materials, which is one of the requirements for a new mechanistic design method in flexible pavement. Adequate knowledge of the strength and deformation characteristics of unbound layer in pavements is a prerequisite for proper thickness design, residual life determination, and overall economic optimization of the pavement structure. The current knowledge concerning the granular materials employed in pavement structures is limited. In addition, to date, no general framework has been established to explain satisfactorily the behaviour of unbound granular materials under the complex repeated loading which they experience. In this study, a conceptual method, packing theory-based model is introduced; this framework evaluates the stability and performance of granular materials based on their packing arrangement. In the framework two basic aggregate structures named as Primary Structure (PS), and Secondary Structure (SS). The Primary Structure (PS) is a range of interactive grain sizes that forms the network of unbound granular materials. The Secondary Structure (SS) includes granular materials smaller than the primary structure. The Secondary Structures fill the gaps between the particles in the Primary Structure and larger particles essentially float in the skeleton. In this particular packing theory-based model; the Primary Structure porosity, the average contact points (coordination number) of Primary Structure, and a new parameter named Disruption Potential are the key parameters that determine whether or not a particular gradation results in a suitable aggregate structure. Parameters mentioned above play major role in the aggregate skeleton to perform well in terms of resistance to permanent deformation as well as load carrying capacity (resilient modulus). The skeleton of the materials must be composed of both coarse enough and a limited amount of fine granular materials to effectively resist deformation and carry traffic loads. QC 20120601

Diamond has excellent optical properties including broadband transmissivity, low self- absorption and a high refractive index, which have prompted its use in for optical sensing applications. Thin-film diamond strip waveguides (DSWGs) combined with tunable quantum cascade lasers (tQCLs) providing an emission wavelength range of 5.78-6.35 μm (1735-1570 cm-1) have been used to obtain mid-infrared (MIR) spectra of proteins, thereby enabling the analysis of their secondary structure via the amide I band. Three different proteins were analyzed, namely bovine serum albumin (BSA), myoglobin, and γ-globulin. The secondary structure of BSA and myoglobin has a major contribution of -helices, whereas γ-globulins are rich in β-sheet structures, which is reflected in the amide I band. A comparison of the spectra obtained via the combination of the tQCL and DSWG with spectra obtained using conventional Fourier transform infrared (FTIR) spectroscopy and a commercial diamond attenuated total reflection (ATR) element has been performed. It is shown that the main features evident in FTIR-ATR spectra are also obtained using tQCL-DSWG sensors., submittedVersion