Cost-effective seismic exploration: 2D reflection imaging at the Kylylahti massive sulfide deposit, Finland

We show that by using an advanced pre-stack depth imaging algorithm it is possible to retrieve meaningful and robust seismic images with sparse shot points, using only 3-4 source points per kilometer along a seismic profile. Our results encourage the use of 2D seismic reflection profiling as a reconnaissance tool for mineral exploration in areas with limited access for active seismic surveys. We used the seismic data acquired within the COGITO-MIN project comprising two approximately 6 km long seismic reflection profiles at the polymetallic Kylylahti massive sulfide mine site in eastern Finland. The 2D seismic data acquisition utilized both Vibroseis and dynamite sources with 20 m spacing and wireless receivers spaced every 10 m. For both source types, the recorded data show clear first breaks over all offsets and reflectors in the raw shot gathers. The Kylylahti area is characterized by folded and faulted, steeply dipping geological contacts and structures. We discuss post-stack and pre-stack data processing and compare time and depth imaging techniques in this geologically complex Precambrian hardrock area. The seismic reflection profiles show prominent reflectors at 4.5-8 km depth utilizing different migration routines. In the shallow subsurface, steep reflectors are imaged, and within and underneath the known Kylylahti ultramafic body reflectivity is prominent but discontinuous.Peer reviewe

Seismic mineral exploration at different scales in the Outokumpu Ore District, Eastern Finland

Non peer reviewe

Crystal structure of thebaine 6-O-demethylase from the morphine biosynthesis pathway

Thebaine 6-O-demethylase (T6ODM) from Papaver somniferum (opium poppy) is a key enzyme in the morphine biosynthesis pathway that belongs to the non-heme 2-oxoglutarate/Fe(II)-dependent dioxygenases (ODD) family. Initially, T6ODM was characterized as an enzyme catalyzing Odemethylation of thebaine to neopinone and oripavine to morphinone, however recently the substrate range of T6ODM was expanded to a number of various benzylisoquinoline alkaloids. Here, we present crystal structures of T6ODM in complexes with 2-oxoglutarate (T6ODM:2OG, PDB: 5O9W) and succinate (T6ODM:SIN, PDB: 5O7Y). The arrangement of the T6ODM’s active site is typical for proteins from the ODD family, but the enzyme is characterized by a large substrate binding cavity, whose volume can partially explain the T6ODM promiscuity. Moreover, the size of the cavity allows for binding of multiple molecules at once, posing a question about substrate-driven specificity of the enzyme

Assessment of highly repellent surfaces

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonHighly repellent surfaces are constantly being sought in a number of industrial sectors, where accumulation of unwanted material (ice, debris, insects etc…) can cause seriously detrimental effects on these function. The chemistry and physics of such surfaces is relatively well-understood, yet their industrial adoption is still very limited, due to their poor durability. Emerging technologies for nanostructured coatings have significant potential for the development of advanced surfaces, where high repellency can be combined with mechanical robustness. However, lack of understanding of the wear mechanism in such coatings and lack of recognised test methodologies to enable comparison of various approaches hinders effective progress in advanced surfaces development. Furthermore, there is no comprehensive classification system that allows categorization of highly repellent surfaces. New multi-variable analysis methodology for the evaluation of durability in highly repellent coatings was developed in this study. Key coating parameters were identified, including initial wettability, abrasive wear, adhesive wear and ability to retain repellency. Coating characteristics were examined with FTIR, SEM, AFM, DSA, Taber Abrader, roughness profilometer and goniometer. Furthermore, these characteristics were presented in a form of spider diagrams and performance indices and are used to generate plot of performance indices. In this study, six types of TWI coating anti-soiling materials (based on patented TWI’s Vitolane® technology, containing silsesqioxanes and functionalized silica nanoparticles) and two commercial easy clean products were prepared and subjected to new assessment methodology. It has been found that this novel methodology for evaluation of highly repellent surfaces allows comparison and categorizing different families of coatings. The data obtained from plot of performance indices supports the statement that there is an inverse relation between repellency and durability of hydrophobic surfaces. It has been found that coatings with low Ra value (no more than 10nm) and symmetric distribution of peaks and valleys are the most durable, yet their WCA value doesn’t exceed more than 105°. It has been also found that some nanostructured coatings behave beyond this inverse relationship. Addition of novel inorganic building blocks with controlled size (Ra in a range of 200nm and symmetric distribution in roughness profile) and functionalities (3-(trimethoxysilyl)propyl methacrylate and 1H 1H 2H 2H-perfluorooctyltriethoxysilane) improves overall coating performance by linking mechanical robustness with desired wetting characteristics (WCA reaches 112°C). The progress in testing and classification criteria of repellent coatings enables further development of next generation of materials. This novel knowledge-based approach for highly repellent coatings validation has the potential to accelerate uptake. The findings open a promising new direction in materials development, where advanced coatings and surface treatments can be developed by design, reducing the number of development iterations, ultimately leading to reduced cost and development time

Towards a viable method of reusing silicon carbide. Physicochemical analyses in the studies on the industrial application of the material

The paper presents an investigation on the feasibility of recovery of the highly valuable silicon carbide (SiC) from the slurry waste generated from silicon wafer production in the photovoltaic and semiconductor industry. Compared to the other techniques of recycling, a facile and low-cost method of waste treatment via heat drying followed by low-energy mixing in a shaker mixer was proposed. As the result of the treatment, the slurry waste was converted into a powdered form with dominant content of SiC. Separated SiC material was characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray powder diffraction, and sieve analysis. In addition, analyses of the bulk density, moisture content and melting test were carried out. As was confirmed by the physicochemical analyses, the dominant sieve fraction was in the range of 0.1-0.06 mm, the purity level was a minimum 99% mass of SiC, the moisture content - 0.3%, the bulk density - 1.3 g/cm3. The physicochemical characteristics of the material were crucial for understanding the material performance, assessment of the material quality and determining the perspective directions of the industrial application. The studies revealed that the material exhibited a high application potential as abrasive, especially in abrasive grinding and waterjet cutting

Efficacy and safety of apixaban vs warfarin in patients with atrial fibrillation and prior bioprosthetic valve replacement or valve repair : Insights from the ARISTOTLE trial

Background The optimal anticoagulation strategy for patients with atrial fibrillation (AF) and bioprosthetic valve (BPV) replacement or native valve repair remains uncertain. Hypothesis We evaluated the safety and efficacy of apixaban vs warfarin in patients with AF and a history of BPV replacement or native valve repair. Methods Using data from Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) (n = 18 201), a randomized trial comparing apixaban with warfarin in patients with AF, we analyzed the subgroup of patients (n = 251) with prior valve surgery. We contacted sites by telephone to obtain additional data about prior valve surgery. Full data were available for 156 patients. The primary efficacy endpoint was stroke/systemic embolism. The primary safety endpoint was major bleeding. Treatment groups were compared using a Cox regression model. Results In ARISTOTLE, 104 (0.6%) patients had a history of BPV replacement (n = 73 [aortic], n = 26 [mitral], n = 5 [mitral and aortic]) and 52 (0.3%) had a history of valve repair (n = 50 [mitral], n = 2 [aortic]). Among patients with BPVs, 55 were randomized to apixaban and 49 to warfarin. Among those with a history of native valve repair, 32 were randomized to apixaban and 20 to warfarin. Overall clinical event rates were low, with no significant differences between apixaban and warfarin for any outcomes. Conclusions In patients with AF and a history of BPV replacement or repair, the safety and efficacy of apixaban compared with warfarin was consistent with results from ARISTOTLE. These data suggest that apixaban may be reasonable for patients with BPVs or prior valve repair, though future larger randomized trials are needed. ClinicalTrials.gov NCT00412984

Novel copolymers of vinyl acetate. 3 Ring-substituted ethyl 2-cyano-3-phenyl-2-propenoates

Novel copolymers of vinyl acetate and ring-substituted ethyl 2-cyano-3-phenyl-2-propenoates, RPhCH=C(CN)CO2C2H5 (where R is 4-acetoxy, 4-acetamido, 2-cyano, 3-cyano, 4-cyano, 4-dimethylamino, 4-diethylamino, 2,4,6-trimethyl, 2,3-dimethyl-4-methoxy, 2,4-dimethoxy-3-methyl were prepared in solution with radical initiation at 70C. The propenoates were synthesized by the piperidine catalyzed Knoevenagel condensation of ring-substituted benzaldehydes and ethyl cyanoacetate, and characterized by CHN analysis, IR, 1H and 13C-NMR. The compositions of the copolymers were calculated from nitrogen analysis and the structures were analyzed by IR, 1H and 13C-NMR. Thermal behavior of the copolymers was studied by DSC (Tg) and TGA. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 160-350ºC range with residue (1.5-15.1 wt%), which then decomposed in the 500-650ºC range