Scintillation detector for carbon-14

Detector consists of plastic, cylindrical double-wall scintillation cell, which is filled with gas to be analyzed. Thin, inner cell wall is isolated optically from outer (guard) scintillator wall by evaporated-aluminum coating. Bonding technique provides mechanical support to cell wall when device is exposed to high temperatures

Enhancing ordering dynamics in solvent-annealed block-copolymer films by lithographic hard masks supports

We studied solvent-driven ordering dynamics of block copolymer films supported by a densely cross-linked polymer network designed as organic hard mask (HM) for lithographic fabrications. The ordering of microphase separated domains at low degrees of swelling corresponding to intermediate/strong segregation regimes was found to proceed significantly faster in films on a HM layer as compared to similar block copolymer films on silicon wafers. The ten-fold enhancement of the chain mobility was evident in the dynamics of morphological phase transitions and of related process of terrace-formation on a macroscale, as well as in the degree of long-range lateral order of nanostructures. The effect is independent of the chemical structure and on the volume composition (cylinder-/ lamella-forming) of the block copolymers. In-situ ellipsometric measurements of the swelling behavior revealed a cumulative increase in 1-3 vol. % in solvent up-take by HM-block copolymer bilayer films, so that we suggest other than dilution effect reasons for the observed significant enhancement of the chain mobility in concentrated block copolymer solutions. Another beneficial effect of the HM-support is the suppression of the film dewetting which holds true even for low molecular weight homopolymer polystyrene films at high degrees of swelling. Apart from immediate technological impact in block copolymer-assisted nanolithography, our findings convey novel insight into effects of molecular architecture on polymer-solvent interactions.Comment: This document is the unedited Author's version of a Submitted Work that was subsequently accepted for publication in Macromolecules, copyright \c{opyright} American Chemical Society after peer review. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/ma500561

The Effects of Grazing and Trampling Upon Certain Soil Properties

The purpose of this study was to obtain basic information about the effects of grazing and trampling on various physical properties of the soil. Included are data on soil texture, rate of infiltration, soil moisture, degree of compaction, aggregate stability, and yields of vegetation under three main treatments. Research was also carried out in paths, congested areas, and artificially compacted plots. The 2 paths were located on moderately-deep soil on a gently-sloping hillside. Composition of the vegetation was similar to that of the moderately grazed site

Experiences with and benefits of the inspection of air-assisted sprayers from the fruit- and winegrowers’ point of view

Until the 1960s pesticides were applied with a spray gun connected to a long hose or directly to the tank and operated by a worker standing on a platform. This technique was gradually replaced by airassisted sprayers.The purchase of three sprayer test facilities in 1991 signified the start of a new era in pesticide application:• The ejection rate of the individual nozzles as well as the distribution pattern of the liquid could be measured and optimized on a vertical test stand by adjusting the nozzles or adding additional ones. • The ceramic nozzles were replaced by hollow-cone nozzles, which allowed for the first time to calculate the exact amount of liquid per hectare and tree height based on various parameters such as driving speed, spray pressure, number of open nozzles and nozzle output volume. The amount of water was reduced from 500 l/m tree height and hectare to 166 – 100 l. • The efficacy of the pesticides was increased and spray drift reduced, which brings about economic and ecological benefits. • Up to the year 1997 sprayer calibration was optional. Since then, a sprayer calibration in 5-year intervals has become a condition for participation in the South Tyrolean IP-programme. This also facilitates the observance of the GobalGAP control points and Compliance Criteria regarding application equipment.Since 2011 the South Tyrolean sprayer manufacturers and fruit- and winegrowers have been able to measure and optimize the air blast and emission pattern. Thereby we hope to further reduce spray drift and increase the efficacy of the pesticides. A properly calibrated sprayer enables the fruit- and winegrowers to observe more easily the regulations for the distances to residential and public buildings as well as pastures enacted by the South Tyrolean Provincial Government and AGRIOS in 2011. We trust that the South Tyrolean fruit- and winegrowers will have no difficulties in complying with the Directive 2009/128/EC on the sustainable use of pesticides with regard to application techniques and sprayer calibration

Submicrometric Films of Surface-Attached Polymer Network with Temperature-Responsive Properties

Temperature-responsive properties of surface-attached poly(N-isopropylacrylamide) (PNIPAM) network films with well-controlled chemistry are investigated. The synthesis consists of cross-linking and grafting preformed ene-reactive polymer chains through thiol--ene click chemistry. The formation of surface-attached and cross-linked polymer films has the advantage of being wellcontrolled without any caution of no-oxygen atmosphere or addition of initiators. PNIPAM hydrogel films with same cross-link density are synthesized on a wide range of thickness, from nanometers to micrometers. The swelling-collapse transition with temperature is studied by using ellipsometry, neutron reflectivity, and atomic force microscopy as complementary surface-probing techniques. Sharp and high amplitude temperature-induced phase transition is observed for all submicrometric PNIPAM hydrogel films. For temperature above LCST, surface-attached PNIPAM hydrogels collapse similarly but without complete expulsion of water. For temperature below LCST, the swelling of PNIPAM hydrogels depends on the film thickness. It is shown that the swelling is strongly affected by the surface attachment for ultrathin films below $\sim$150 nm. For thicker films above 150 nm (to micrometers), surface-attached polymer networks with the same cross-link density swell equally. The density profile of the hydrogel films in the direction normal to the substrate is confronted with in-plane topography of the free surface. It results that the free interface width is much larger than the roughness of the hydrogel film, suggesting pendant chains at the free surface.Comment: in Langmuir, American Chemical Society, 2015, LANGMUIR, 31 (42), pp.11516-1152

Controls on development and diversity of Early Archean stromatolites

The ≈3,450-million-year-old Strelley Pool Formation in Western Australia contains a reef-like assembly of laminated sedimentary accretion structures (stromatolites) that have macroscale characteristics suggestive of biological influence. However, direct microscale evidence of biology—namely, organic microbial remains or biosedimentary fabrics—has to date eluded discovery in the extensively-recrystallized rocks. Recently-identified outcrops with relatively good textural preservation record microscale evidence of primary sedimentary processes, including some that indicate probable microbial mat formation. Furthermore, we find relict fabrics and organic layers that covary with stromatolite morphology, linking morphologic diversity to changes in sedimentation, seafloor mineral precipitation, and inferred microbial mat development. Thus, the most direct and compelling signatures of life in the Strelley Pool Formation are those observed at the microscopic scale. By examining spatiotemporal changes in microscale characteristics it is possible not only to recognize the presence of probable microbial mats during stromatolite development, but also to infer aspects of the biological inputs to stromatolite morphogenesis. The persistence of an inferred biological signal through changing environmental circumstances and stromatolite types indicates that benthic microbial populations adapted to shifting environmental conditions in early oceans