Blown film thickness control with a scanning down-the-line measurement

The thickness profile of the tubular bubble in blown film extrusion is deduced from delayed measurements made downstream in the flatted web consisting of the bubble. Scanner moving across the web measures only a portion of it at a time and the measurement results are matched to the bubble profile at actuators controlling the thickness. The delayed profile is predicted to current time and used for LQR feedback control. The control architecture is tested in a simulation of the process.acceptedVersionPeer reviewe

Electrospun sodium titanate fibres for fast and selective water purification

From the environmental and end-​users' viewpoints, electrospun ion exchange fibres provide highly efficient and sustainable material for separation of for example trace pollutants, such as radionuclides and heavy metals. This work aimed to reduce the amount of ion exchange material needed per unit volume of raw material subjected to an ion exchange process. We present a very simple process to electrospinning of sodium titanate fibres, but also test results of ion exchange kinetics measurements. Sodium titanate fibres are very promising material and it is possible that by exploiting electrospun inorganic sub-​micron fibres the ion exchanger mass required for a given capacity can be decreased significantly.Peer reviewe

Conceptual model for capability planning in a military context – A systems thinking approach

During recent decades, planning defense systems have evolved into capability-based planning (CBP) processes. This paper seeks to answer two questions: firstly, how to express a complex, real-world capability requirement; and secondly, how to assess if a system with interacting elements fulfills this requirement. We propose that both a capability need and the solution fulfilling it are expressed with a consistent set of models in a traceable manner. The models integrate current capability models, specific to planning level and capability viewpoint, with systems thinking approach. Our conceptual model defines the defense system in its environment, our data model defines and organizes the CBP terms, and our class diagram defines the CBP planning elements. We illustrate the approach by giving an example of capability parametrization and compare it both with the DODAF capability view and with the generic CBP process. Our data model describes how capabilities are degraded in action and extends the approach toward capability dynamics. The quantitative capability definition aims to support efforts to solve for real world interacting subsystems that combined implement the required capability.publishedVersionPeer reviewe

Sb-doped zirconium dioxide submicron fibers for separation of pertechnetate (TcO4-) from aqueous solutions

Submicron ZrO(2)fibers with three different Sb-doping levels (5, 10 and 15 cation%) were produced with an electroblowing synthesis for removal of(99)TcO(4)(-). The Sb-doped ZrO(2)fibers showed high selectivity toward(99)TcO(4)(-), which was not interfered by ClO4-, NO(3)(-)or Cl(-)ions and showed no selectivity toward ReO4-. The optimal pH range for the(99)Tc separation was 2-6 but the Sb-doped fibers maintained very high uptake level throughout the studied pH range of 1-10. According to the uptake experiments, Sb(III) is assumed to reduce Tc(VII) to Tc(IV) that is then adsorbed by the zirconia surface.Peer reviewe

Submicron fibers as a morphological improvement of amorphous zirconium oxide particles and their utilization in antimonate (Sb(v)) removal

Mesoporous and large surface area zirconium oxide aggregate granules with good adsorption properties were synthesized using a simple precipitation method. Since utilization of these small and fragile particles is considered rather difficult in larger scale column operation, the product was formed into a fibrous form to improve its usability. The submicron fibers were obtained from an optimized electroblowing synthesis that resulted in elastic and uniform fibers with a tetragonal structure and high length-to-diameter ratio. In antimonate (Sb(v)) adsorption experiments, the higher calcination temperature (350 degrees C) of the fibers did not seem to decrease the Sb(v) adsorption capacity excessively since the high theoretical adsorption capacities were 113 mg g(-1) and 58 mg g(-1) for the aggregate and fibers, respectively. Both materials had fast kinetics, fibers being faster in the beginning of the reaction. Moreover, both materials offered efficient Sb(v) removal in the studied pH range from 1 to 11 by reaching over 99.9% adsorption in the optimal pH range. X-ray absorption near edge spectroscopy (XANES) revealed that Sb(v) stays as pentavalent antimony after being adsorbed by these materials and based on the isoelectric point shifts in the zeta potential measurement, adsorption occurs mainly by an inner-sphere complexation reaction. Finally, our study showed that pressure buildup in a flow-through column packed with zirconium oxide fibers was significantly lower than in a column packed with aggregates. Thus, zirconium oxide aggregates can be formed into submicron fibers with enhanced column operation properties without a too large compromise in the adsorption properties.Peer reviewe

Electroblown titanium dioxide and titanium dioxide/silicon dioxide submicron fibers with and without titania nanorod layer for strontium(II) uptake

Nuclear power is a clean alternative to fossil fuels. However, the use of nuclear energy generates hazardous fission products of which 90Sr is the second most important. To remove Sr2+ from aqueous solutions, we synthesized submicron TiO2 and TiO2/SiO2 composite fibers with Ti : Si molar ratios of 3 : 1 (3TiO2–1SiO2) and 1 : 1 (1TiO2–1SiO2) utilizing a novel electroblowing technique. After calcination at 500 °C, the TiO2 and 3TiO2–1SiO2 fibers had a predominantly anatase TiO2 structure with portions of rutile and brookite but the crystallites in the 3TiO2–1SiO2 fibers were smaller due to the SiO2 component. The 1TiO2–1SiO2 fibers were quasi-amorphous. Rutile TiO2 nanorods were grown on the fibers by a hydrothermal method. The rods seemed to grow only on the TiO2 domains of the fiber surface, which affected their size and morphology. In batch adsorption experiments all the fibers had excellent Sr2+ uptake with the hydrothermally modified TiO2 fibers having the highest distribution coefficient (Kd) of 3,490,000 mL g−1. The results show that both anatase and rutile TiO2 can efficiently adsorb Sr2+ from an aqueous environment. Hardly any damage was observed in the nanorods on the TiO2 fibers in a column operation test with flow rates up to 74 mL h−1 which is promising for the use of the fibers in industrial column mode wastewater treatment.Peer reviewe

Perusteita seuraavan sukupolven metsävarajärjestelmälle – Forest Big Data -hanke

Tieteen tori: Yksityiskohtainen metsävaratiet

Novel electroblowing synthesis of tin dioxide and composite tin dioxide/silicon dioxide submicron fibers for cobalt(II) uptake

Nanoscale SnO2 has many important properties ranging from sorption of metal ions to gas sensing. Using a novel electroblowing method followed by calcination, we synthesized SnO2 and composite SnO2/SiO2 submicron fibers with a Sn : Si molar ratio of 3 : 1. Different calcination temperatures and heating rates produced fibers with varying structures and morphologies. In all the fibers SnO2 was detected by XRD indicating the SnO2/SiO2 fibers to be composite instead of complete mixtures. We studied the Co2+ separation ability of the fibers, since Co-60 is a problematic contaminant in nuclear power plant wastewaters. Both SnO2 and SnO2/SiO2 fibers had an excellent Co2+ uptake with their highest uptake/K-d values being 99.82%/281 000 mL g(-1) and 99.79%/234 000 mL g(-1), respectively. Compared to the bare SnO2 fibers, the SiO2 component improved the elasticity and mechanical strength of the composite fibers which is advantageous in dynamic column operation.Peer reviewe