4,074 research outputs found
Synthesis optimization and charge carrier transfer mechanism in LiLuSiO<sub>4</sub>:Ce, Tm storage phosphor
No full textLiLuSiO4:Ce and LiLuSiO4:Ce, Tm show very efficient charge carrier storage properties upon beta irradiation after samples have received treatment in vacuum. They outperform the commercial storage phosphor BaFBr(I):Eu2+ in many aspects. The influence of the synthesis conditions, Ce and Tm concentration, nonstoichiometry and codoping with Ca, Hf, Al and Ge are reported. Based on the results of the synthesis optimization, thermoluminescence (TL) emission and TL excitation spectra a mechanism of charge carrier transfer, storage, and recombination during irradiation and thermal or optical readout is proposed.Accepted Author ManuscriptRST/Fundamental Aspects of Materials and EnergyRST/Luminescence Material
Cloning and gene structure of the rod cGMP phosphodiesterase delta subunit gene (PDED) in man and mouse
No full textRod-specific cGMP phosphodiesterase (PDE) is a key enzyme of the phototransduction cascade, and mutations in its catalytic subunits have been associated with retinal degenerative diseases, The bovine Q-subunit solubilises the normally membrane-bound PDE and is the only subunit expressed in extraocular tissues, We isolated the human and mouse orthologs, and found 78% identity at the DNA level and 98% identity at the protein level, The Caenorhabditis elegans homolog shows 69% identity at the protein level, The human PDED gene consisted of 5 exons spanning at least 30 kb of genomic DNA, Northern blot analysis showed a 1,3 kb transcript in human retina, heart, brain, placenta, liver, and skeletal muscle, Fluorescence in situ hybridisation (FISH) and radiation hybrid mapping localised the human PDED gene to chromosome 2q37, A preliminary screen of all 5 exons in 20 unrelated patients with autosomal recessive retinitis pigmentosa revealed no PDED mutations
GA Landsat 5 TM Analysis Ready Data Collection 3
No full textMaintenance and Update Frequency: asNeededStatement: This product is derived from the USGS Landsat Collection 1 archive.
The Moderate Resolution Imaging Spectroradiometer (MODIS) MCD43A1 Version 6 Bidirectional Reflectance Distribution Function and Albedo (BRDF/Albedo) Model Parameters dataset was provided by the National Aeronautics and Space Administration (NASA). It was produced daily using 16 days of Terra and Aqua MODIS data at 500 m resolution.
The ozone data was provided by Environment Canada.
The Aerosol Optical Thickness data was provided by the Commonwealth Scientific and Industrial Research Organisation (CSIRO).
The Precipitable Water for Entire Atmosphere data was provided by the National Oceanic and Atmospheric Administration (NOAA) / Earth System Research Laboratory (ESRL) / Physical Sciences Division (PSD).
The baseline Digital Surface Model (DSM) data produced from the Shuttle Radar Topography Mission (SRTM) was provided by the National Geospatial-Intelligence Agency (NGA).
Level 1 Collection 1 data was provided by the United States Geological Survey (USGS)'s Earth Resources Observation and Science (EROS) Center.<b>BACKGROUND</b><br/><p><br/><p>The United States Geological Survey's (USGS) Landsat satellite program has been capturing images of the Australian continent for more than 30 years. This data is highly useful for land and coastal mapping studies. <br/><p>In particular, the light reflected from the Earth’s surface (surface reflectance) is important for monitoring environmental resources – such as agricultural production and mining activities – over time. <br/><p>We need to make accurate comparisons of imagery acquired at different times, seasons and geographic locations. However, inconsistencies can arise due to variations in atmospheric conditions, sun position, sensor view angle, surface slope and surface aspect. These need to be reduced or removed to ensure the data is consistent and can be compared over time. <br/><p> </p><br/><b>WHAT THIS PRODUCT OFFERS</b><br/><p><br/><p>GA Landsat 5 TM Analysis Ready Data Collection 3 takes Landsat 5 Thematic Mapper (TM) imagery captured over the Australian continent and corrects for inconsistencies across land and coastal fringes. The result is accurate and standardised surface reflectance data, which is instrumental in identifying and quantifying environmental change. <br/><p><br/><p>The TM instrument is an advanced, multispectral scanning, Earth resources sensor which is designed to categorise the Earth's surface. It is particularly useful for agricultural applications and identification of land use. <br/><p><br/><p>This product is a single, cohesive Analysis Ready Data (ARD) package, which allows you to analyse surface reflectance data as is, without the need to apply additional corrections. <br/><p><br/><p>It contains three sub-products that provide corrections or attribution information:<br/><p><br/><p> 1) GA Landsat 5 TM NBAR Collection 3 <br/><p> 2) GA Landsat 5 TM NBART Collection 3<br/><p> 3) GA Landsat 5 TM OA Collection 3<br/><p><br/><p>The resolution is a 30 m grid based on the USGS Landsat Collection 1 archive
The dependence of light extraction improvement on optimized surface microstructure for AlGaN-based UVC-LEDs considering TM-polarized emission
No full textIn order to improve the light extraction of AlGaN-based short wavelength ultraviolet light emitting diodes (DUC-LEDs), a type of microstructure with high aspect ratio is introduced and optimized on the AlN substrate surface. And, particle swarm optimization (PSO) algorithm is used to inverse design of the surface microstructure to maximize the light extraction efficiency (LEE). Considering that the propagation characteristics of TM-polarized light are different from that of TE-polarized light, the optical field distribution and LEE is analyzed for the UVC-LEDs with different TE-polarized component when the optimized surface microstructure is applied. Furthermore, the preparation process tolerance of the high aspect ratio structure is discussed by calculating the LED's LEE when the structural deviation occurs or morphology changes. Simulation results show that, by using the optimized surface microstructure based on parabola cone array, the LEDs' LEE is increased from 4.4% to 8.7% and from 0.4% to 3.7% for TE-polarized and TM-polarized emission, respectively. In addition, it is demonstrated that the light extraction improvement by the surface microstructure has a good tolerance to the structural deviation and morphology. The results are significant for improving light extraction and realizing high efficient short wavelength AlGaN-based UVC-LEDs by designing surface microstructures.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.ImPhys/Esmaeil Zadeh grou
Rigor and relevance in empirical TM research: Key issues and challenges Author links open overlay panel
No full textThis paper aims to offer a critical reflection on the way Talent Management (TM) is investigated in practice, by addressing the key issues regarding the quality (in terms of rigor and relevance) of academic empirical TM research and therefore the critical scrutiny of TM scholars’ work. We will argue that despite the growth in the quantity, the quality of many empirical TM papers is lagging behind and hindering the progress of the academic field of TM. Based on a content analysis of 174 peer-reviewed articles published between 2006 and 2017, the paper outlines nine critical issues regarding the quality of the existent empirical TM research. In order to improve the positioning of the field as well as the impact of TM research on practice itis absolutely necessary for TM scholars to secure the quality of academic empirical TM research. Also, the collaboration between practitioners and scholars should increase.Peer ReviewedPostprint (author's final draft
Rigor and relevance in empirical TM research: Key issues and challenges Author links open overlay panel
No full textThis paper aims to offer a critical reflection on the way Talent Management (TM) is investigated in practice, by addressing the key issues regarding the quality (in terms of rigor and relevance) of academic empirical TM research and therefore the critical scrutiny of TM scholars’ work. We will argue that despite the growth in the quantity, the quality of many empirical TM papers is lagging behind and hindering the progress of the academic field of TM. Based on a content analysis of 174 peer-reviewed articles published between 2006 and 2017, the paper outlines nine critical issues regarding the quality of the existent empirical TM research. In order to improve the positioning of the field as well as the impact of TM research on practice itis absolutely necessary for TM scholars to secure the quality of academic empirical TM research. Also, the collaboration between practitioners and scholars should increase.Peer Reviewe
Dalla Biblioteca Comunale di Urbania: due raccolte musicali per un interprete
No full textIn the Library of Urbania (Marche, Italy) six musical manuscripts containing seventeenth century arias and cantatas are preserved. They belonged to an aristocratic family of Apecchio, (Marche), the Ubaldini. This article investigates two of them containing cantatas by Cossoni, Giovanni Bonaventura Viviani, Legrenzi Bassani and others, and in which there is the note “ex libris Antonij Barbarini”. This article reconstructs the origin of these two manuscripts, for whom the author individuated the probable owner, the singer Ippolito Fusai, by means the repertory identified in it. A thorough investigation of this hitherto little-known manuscripts may shed new light on the diffusion and transmission of music in Italy during the Seventeenth and early-Eighteenth centurie
Determination of the "new" problem group chloroparaffins in sediments by HRGC-LRMS
No full textChloroparaffins (CPs) are complex mixtures of n-alkanes homologues with variable chain lengths
and chlorine contents consisting of several thousands of congeners, homologues, isomers and
enantiomers. Although chloroparaffins belong to chemicals of high volume production, little
attention has been paid to the analysis and environmental levels of these compounds in the last
decades. Short chain chloroparaffins have been included in several regulation programs worldwide
since studies demonstrated toxicity to aquatic organisms. However, environmental levels still
missing for a detailed risk assessment, especially for aquatic systems.
The aim of the work was to develop a method for the determination of short and medium chain
chloroparaffins in sediments. The clean-up should be as simple as possible and the detection carried
out by high resolution gas chromatography (HRGC) coupled to low resolution mass spectrometry
(LRMS). In total, three mass spectrometric methods were applied for the detection of
chloroparaffins in sediments using different ionization techniques (electron ionization (EI), electron
capture negative ionization (ECNI) and chloride attachment chemical ionization (CACI)). They
allowed to determine short (SCCP) and medium chain CP (MCCP) levels and patterns in sediments
from the North and Baltic Sea.
Soxhlet extraction was followed by a clean-up consisting of adsorption chromatography with silica
gel and Florisil®, which allowed the separation of CPs from other interfering organochlorines such
as polychlorinated biphenyls, toxaphene and DDT-related compounds.
At first, thirty three sediments from the North and Baltic Sea were investigated by EI-MS/MS.
Secondly, eight additional sediments from the Seine estuary, Tromsø and Hamburg harbour were
analysed as well as fifteen suspended particular matter samples from the rivers Rhine, Neckar, Elbe
and from the North Sea. EI-MS/MS allowed simultaneous determination of short, medium and long
chain chloroparaffins. Concentrations ranged between 5-355 ng/g dry weight (d.w.) for the North
Sea, 45-377 ng/g d.w. for the Baltic Sea, 70-156 ng/g d.w. for the Seine estuary and the harbours of
Tromsø and Hamburg as well as 127-669 ng/g d.w. for the samples from Rhine and Neckar.
The application of ECNI-MS and CACI-MS allowed the separate quantification of short and
medium chain chloroparaffins and of the homologue and congener group patterns. SCCP
concentrations ranged between 8-144 ng/g d.w. and MCCP between 23-407 ng/g d.w. in twenty
eight samples (ECNI-MS). The SCCP and MCCP content was determined in those samples
exceeding ca. 50 ng/g total CP. Below this level the quantities were too low for this differentiation
based on single formular and congener groups. MCCP levels were highest in all samples.
Differences in the CP patterns were obtained. Sea sediments were predominated by chlorinated doand
tridecanes and those from rivers, harbours and suspended particular matter samples by
chlorinated un- and dodecanes. No difference was observed between the MCCP patterns.
Concentrations obtained by CACI-MS were in the range of 13-128 ng/g d.w. for SCCP and between
36-303 ng/g d.w. for MCCP in eighteen sediments from the North and Baltic Sea. The
MCCP/SCCP ratios varied between 1.5 and 3.2 and were in good agreement (< 25% relative
deviation) with the same sampling location and different years of sample collection. Results
obtained by the three methods were in a good agreement with each other (< 34% relative standard
deviation).
Furthermore, principal component analysis (PCA) was applied to compare the CP patterns of
sediments and suspended particular matter with those of technical mixtures from European
producers. Congener and homologue group patterns of marine sediments showed similarities with
technical SCCP and MCCP mixtures and differences with those of river sediments and suspended
particular matter (ECNI-MS). CP patterns of marine sediments obtained by CACI-MS were similar
to technical mixtures with chlorine contents < 50%. Additionally, cluster analysis (CA) was used
for the differentiation between technical SCCP and MCCP mixtures. The main criterion of
differentiation was the degree of chlorination.
Congener and homologue group patterns of technical SCCP and MCCP mixtures were registered
and compared using ECNI-MS and CACI-MS. In contrast to CACI-MS, homologue and congener
group patterns obtained by ECNI-MS showed always a shift to the next higher chlorinated congener
of the same carbon chain length group. Consequently, the calculated molecular masses and chlorine
contents were always higher for ECNI-MS. However, for sediment samples a pronounced shift to
congeners with 2-3 more chlorine atoms was observed due to interfering compounds not removed
by the clean-up.
Technical CP mixtures and sediments were also characterized by comprehensive two-dimensional
(GC×GC) gas chromatography coupled to quadrupole LRMS. For single CP mixtures with the same
chlorine content but different carbon chain lengths the same main CP congeners were detected, e.g.
congeners with 5-8 chlorine atoms for mixtures with 50% chlorine content. Separation of MCCPs a
SCCPs could not be achieved with the selected stationary phase combination of ZB1-ms (first
column) and DB-17MS (second column). The applicability of this method was demonstrated for
sediments.
The developed clean-up procedure allowed also the determination of chlordane compounds in sea
sediments. Detection was carried out by conventional ECNI-MS on two different instruments and
by a newly developed method based on electron ionization tandem mass spectrometry (MS/MS).
This method showed comparable detection limits in the low pg range except for cisheptachlorepoxide,
where detection limits were higher one order of magnitude. Levels of
heptachlor, trans/cis-chlordane and trans/cis–nonachlor were determined. The concentrations
ranged between 7-144 pg/g d.w. for trans-nonachlor, < 2-29 pg/g d.w. for the cis isomer, < 2-135
pg/g d.w. for trans-chlordane, < 7-126 pg/g d.w. for cis-chlordane and 42-64 pg/g d.w. for
heptachlor. trans-Nonachlor concentrations were highest in all samples
Preferred Reporting Items for the Development of Evidence-based Clinical Practice Guidelines in Traditional Medicine (PRIDE-CPG-TM): Explanation and elaboration
No full textAbstractIntroductionThe development of evidence-based clinical practice guidelines (CPGs) in traditional medicine (TM) is an ongoing challenge as it is unique area. This study describes a unified platform with Preferred Reporting Items for the Development of Evidence-based CPGs in TM (PRIDE-CPG-TM), which has been successfully used by the evidence-based CPGs committee for TM.MethodsInitially we searched the literature and CPG handbooks, collected items from methodology references and drew on experiences gained from Korean medical physicians and methodology experts. A group of experts subsequently edited drafts of the items, identified one or more examples of good reporting for each item, and developed text that explained the rationale and discussed relevant evidence. Face to face meetings were held with experts to finalize the items with the most extensive elaboration.ResultsThe PRIDE-CPG-TM, in the form of a checklist and description of items with TM approach and TM examples, were designed to improve the reporting of CPG in TM and thereby facilitate their interpretation and replication. The PRIDE-CPG-TM included 5 domains and 40 items. The items pertain to the development methodology (22 items), Overview of diseases and symptoms (6 items), Recommendations (4 items), Implementation and dissemination (5 items) and others (3 items).ConclusionsThe completeness of CPG descriptions in TM is very poor. Therefore, a complete description of the recommendations for TM in CPGs is necessary for physicians to implement the recommendations in clinical practice areas. The PRIDE-CPG-TM will provide useful guidance for TM developers in the development of evidence-based CPGs
Study of Tm valence state in CaSi2O2N2 and phosphor-enabled PowerWindow application
No full textPowerWindow is a luminescent solar concentrator which employs a Tm2+-doped material to strongly absorb sunlight and produce a sharp emission in the near-infrared spectrum for energy-harvesting purposes. The absence of self-absorption and the large spectral overlap with the solar spectrum make it an attractive addition to current building-integrated photovoltaics development. Such Tm2+-doped materials have so far been limited to halides that are susceptible to decomposition when exposed to air, which compromises its stability and limits the application. The solutions to functionalize the characteristic Tm2+ photoluminescence properties are two-fold: by an alternative inorganic host (CaSi2O2N2) that is insensitive to moisture, or by using a protective barrier (silicone) that protects halides against decomposition upon exposure to air. The proposed alternative phosphor CaSi2O2N2:Tm is synthesized by solid-state reaction and its luminescent property is examined. The Tm dopant is found to exist in trivalent state (Tm3+) and no luminescence of Tm2+ is found in the material. Besides Tm2O3, different starting powders with other oxidation states (TmI2 and Tm metal powder) were tested to reduce Tm3+ ion to Tm2+ but no change has been observed. It is concluded that the high-lying Tm2+ 4f electronic ground state in CaSi2O2N2 is susceptible to oxidization by losing electrons to its conduction band and therefore unlikely to be stabilized with this synthesis method. The protective barrier approach applied to the NaCl:Tm2+ phosphors was realized by a polydiphenylsiloxane silicone encapsulant. The precursors and the phosphors are cured together in a lamination scheme between two pieces of glass. From the optical properties derived from its absorption and transmission spectra, it is concluded that the Tm2+ valence state of NaCl:Tm2+ is stable in the polymer with no sign of Tm3+ formation at all. While its production process and the relative amount of phosphor still need to be further optimized, a proof-of concept has been attained
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