117,376 research outputs found
Preparation and characterisation of a wood coating with a luminiscent effect
No full textUgotavljali smo, ali je v premaze za les možno vmešati pigmente z luminiscentnim efektom. Uporabljali smo luminiscentne delce velikosti 10 %m in 4 %m. Pigment nam je uspelo vmešati v premazne sisteme, tako da smo pripravili paleto vzorcev z različnimi koncentracijami pigmenta v premazu, in z različnimi debelinami filmov. Med mešanjem so se zmesi precej segrele. Pripravili smo premaze s 5 %, 10 %, 15 %, 20 %, 30 %, 40 % in 50 % vmešanega pigmenta. Nanose smo izvedli na bukov furnir na iverni plošči ter na masivni hrastov les. Nanašali smo filme nazivnih debelin 40 %m, 120 %m in 240 %m. Utrjevanje filmov je potekalo bodisi na zraku ali z UV svetlobo. Ugotovili smo, da dodani pigment ne vpliva negativno na utrjevanje filma. Vzorce smo nato analizirali v temnici, kjer je luminiscentni efekt prišel najbolj do izraza. S slik, posnetih z digitalnim fotoaparatom ter s pomočjo nekaj računalniških programov smo za vsak vzorec izračunali svetlost L. Ugotovili smo, da večja koncentracija pigmenta v premazu poveča intenziteto in trajanje luminiscenčnega efekta. Prav tako na luminiscenco filmov vplivajo tudi debelina filma, prisotnost omakal, vrsta podlage, vmesno brušenje vmesnih plasti premaznega sistema, število nanosov ter vir svetlobe, ki mu izpostavimo luminiscentni film.We analysed the possibilities of mixing the pigments with a luminescent effect into different wood coatings. We used luminescent particles in sizes of 10 %m and 4 %m. For stirring the pigment into coating systems, we prepared samples with different concentrations of the pigment in the coatings and with different film thicknesses. During the stirring, the mixtures heated significantly. We prepared coatings with 5 %, 10 %, 15 %, 20 %, 30 %, 40 % and 50 % of the pigment. As a substrate we used beech veneered chipboard and oak solid wood. We applied films with the nominal thicknesses of 40 %m, 120 %m and 240 %m. Curing of films was performed in air or with UV light. We found out that the added pigment does not have a negative effect on curing of a film. We analysed the samples in a dark room, where a luminescent effect was the most prominent. From the photos taken with a digital camera and with the help of computer programmes we estimated the brightness (L) of each sample. We ascertained that the intensity and duration of the luminescent effect increase with higher concentration of the pigment in the coating. Luminescence of a film is also influenced by the following factors: film thickness, the presence of a surfactant, substrate type, intermediate sanding of intermediate coating layers, number of coating layers, as well as the source of light to which the luminescent film is exposed to
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Square Dancing with the Stars to Enhance Dynamic Hirschman Linkages?
No full textIn this Presidential Address, the author takes the reader on a reconnaissance of his life and time as a regional scientist. He points out scenery he found scintillating along the way, hoping that some may pick up the banner and chew on a few of the ideas for a while. He suggests a revisit to Albert O. Hirschman’s notion of key sectors and more empirical analysis related to Marcus Berliant’s and Masahisa Fujita’s notion of knowledge creation and transfer.Presidential Address, San Antonio, Texas, March 29, 2014 (53rd Meetings of the Southern Regional Science Association
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
First contribution to the knowledge of coralline algae distribution in the Slovenian circalittoral zone (Northern Adriatic).
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Letter from unknown writer to Jesse L. Boyce
No full textLetter to Jesse L. Boyce from unknown author (possibly Jack) about the investigation into the powder magazine located in the Grand Canyon. Some personal news is included in the letter such as the writer's marriage to the daughter of C.A. Taylor, former Supervisor of Cochise County
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Mercury and methylmercury in the Gulf of Trieste (northern Adriatic sea)
No full textThe distribution, sources and fate of mercury (Hg) in the water column of the Gulf of Trieste (northern Adriatic Sea), affected by the Hg polluted river SocayIsonzo for centuries draining the cinnabar-rich deposits of the Idrija mining district (NW Slovenia), were studied in terms of total and dissolved Hg, reactive Hg, total and dissolved methylmercury (MeHg), mesozooplankton Hg and MeHg, and sedimentation rates of particulate Hg. Higher total Hg
concentrations in the surface layer were restricted to the area of the Gulf in front of the river plume expanding in a westerly direction. Higher concentrations in bottom water layers were the consequence of sediment resuspension. Dissolved Hg exhibited higher concentrations in the surface layer in the area in front of the river plume. Higher bottom concentrations of dissolved Hg observed at some stations were probably due to remobilization from sediments, including resuspension and benthic recycling. The relationship between dissolved Hg in the surface layer and salinity showed nonconservative mixing in June 1995 during higher riverine inflow and nearly conservative mixing in September 1995 during lower riverine inflow. Both mixing curves confirm the river SocayIsonzo to be the most important source of total and dissolved Hg, which are significantly correlated, in the Gulf. Reactive Hg is significantly correlated with dissolved Hg, indicating that the majority of dissolved Hg is reactive and potentially involved in biogeochemical transformations. The higher total MeHg in the bottom layer is the result of remobilization of MeHg from sediments including benthic fluxes. Strong seasonal variation of sedimentation rates of particulate Hg was found during a 2-year study in the central part of the Gulf. These variations followed those of total sedimented matter, indicating that sedimented Hg is mostly associated with inorganic matter. About a 2.5-fold higher fluxes of particulate Hg were observed at the depth of 20 m relative to 10 m which is attributed to bottom sediment resuspension. Temporal variability of mesozooplankton Hg and MeHg is the consequence of biomass and species variations, and grazing behaviour. From the preliminary Hg mass balance it appears that the Gulf is an efficient trap for total Hg and a net source of MeHg
Effect of salinity on condition of Mediterranean killifish (Aphanius fasciatus) and eastern mosquitofish (Gambusia holbrooki) in Škocjanski zatok and their interactions in laboratory conditions
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