bluuebunny/crossref_metadata_2025 huggingface dataset:
Mineral insulation - a critical study
Authors: Winer A A , Wang S B
Published: April 2018

Mineral insulation, a glass fibre product formed from melting mixtures of inorganic material, is a simple and economical component in energy conservation. Because of expected shortages in energy fuels and subsequent increases in costs, all economic sectors will
be effected. The Canada Centre for Mineral and Energy Technology (CANMET) is involved in a project on mineral insulation. As part of this project, a critical study of the literature and field trips to industry have been made and discussions held with experts in insulation technology. Composition of
the inorganic mixture and temperature both influence glass structure, and structure in turn determines glass properties. Important parameters in fiberizing the glass are viscosity, temperature, surface tension and density. Phase equilibria diagrams are very useful in determining optimum composition
and correct fiberizing temperature. Most mineral producers in Canada use the cupola melting furnace and wheel spinning process but the electric furnace is becoming more popular because of its inherent advantages such as the ability to use a finer and therefore more homogeneous charge; it is also
more easily controlled and inhibits environmental pollution. In electric melting, electrical conductivity is an important parameter and is related to the degree of ionization. Tests are performed on mineral insulation products to satisfy standards established for applications in industry, building,
and homes. Such standards are not all uniform across the country but may vary according to local requirements.
Mineral waste resources of Canada report no. 4 - mining wastes in the Atlantic provinces
Authors: Collings R K
Published: April 2018

Legislation restricting mining in many urban centres, exhaustion of ore deposits, and increased cost of locating and developing new orebodies have combined to focus attention on mineral waste accumulations as possible supplemental sources of mineral raw material.
Current annual production of such wastes by the mining industry of Canada is about 800 x 106 t. Only a small portion of this is used because of remote location and low quality, as well as a lack of detailed information on the nature of these wastes and their possible uses. Current applications
include road construction and maintenance, railroad ballast, smelter flux, and mine backfill. Uses being studied by CANMET researchers include the recovery of contained metals and minerals, the production of concrete and construction aggregate, the manufacture of bricks, building blocks and mineral
wool insulation, and use as a mineral filler and soil additive. This report provides background information on waste rock and mill tailings in the Atlantic Provinces where more than 45 x 106 t of such wastes are produced annually. Data on the occurrence, mineralogy, petrography, and physical and
chemical characteristics of wastes from 17 operating mines are provided in tabular form for three principal types of mines - metal, non-metallic or industrial mineral, and coal. Potential uses for these wastes are noted along with relevant research.
The chemistry, generation and treatment of thiosalts in milling effluents - a non-critical summary of CANMET investigations 1976-1982
Authors: Wasserlauf M , Dutrizac J E
Published: April 2018

CANMET's thiosalt program, as well as the relevant open literature on thiosalts, is reviewed in a non-critical manner. Prior to this program, very little was known about thiosalts or their behaviour in milling effluents. Analytical techniques previously available
usually had been tested only on pure synthetic solutions often with only one thiosalt species present. Adequate sampling and storage procedures were not available. Virtually nothing was known about thiosalt generation in milling circuits. Some studies had been made on the chemistry of thiosalts,
especially thiosulphate, and although many of the early studies suffered from analytical uncertainties, they indicated that thiosalt destruction might be achieved by a variety of unevaluated techniques. During CANMET's thiosalt program it was found that thiosalt solutions were somewhat unstable at
room temperature; freezing of solutions appeared to be the best method of sample preservation. Colorimetric analytical methods based on selective cyanolysis of thiosulphate, trithionate and tetrathionate contained in mill effluents were developed and evaluated. Titrimetric methods, based on EDTA
back titration of barium remaining after selective oxidation of the individual thiosalts to SO4 , were developed. The Noranda mercuric chloride total thiosalt titration method was perfected. Methods were tried to permit the determination of low (<50 ppm) thiosalt levels, but these were
subject to large uncertainties. As part of the general analytical work, the infrared and ultraviolet spectra of the dissolved thiosalts were measured; the crystal structures of trithionate and tetrathionate were determined; the crystal structures of trithionate and tetrathionate were accurately
measured. The factors affecting thiosalt generation in milling circuits were determined, and the principal ones were grinding pH, sulphide content of the ore, residence time and temperature. Mass balances were conducted at two operating mills to define the importance of the various unit operations.
Fourteen methods of thiosalt destruction were evaluated on technical and economic grounds. Although some methods such as electrodialysis were the subject of paper studies only, most of the techniques were extensively examined at the laboratory level and those such as biological oxidation, were
tested at pilot scale. When all aspects of the treatment are considered, thiosalt destruction costs become very high; furthermore, none of the methods has yet been proved to be continuously effective for the large-scale treatment of actual thiosalt effluents.
Beneficiated products from fly ash: market research
Authors: Wilson H S , Burns J S
Published: April 2018

Research done in recent years shows that fly ash can be separated into size fractions and components, thus making it a valuable mineral resource. This study examined the state-of-the-art on the beneficiation of fly ash to recover cenospheres, magnetic iron
compounds, and carbon. Methods of beneficiation, applications for products and possible market prices are discussed.
Fibres résistantes aux alcalis: étude documentaire
Authors: Wang S S B
Published: April 2018

This literature review presents background information outlining the function of mineral fibres in cement and concrete mixes. Asbestos fibres are currently used because of their alkali-resistant properties. Newly developed alkali-resistant man-made mineral fibres
(MMMF) have been developed as possible substitutes. Problems relative to such fibres are noted along with the desirability of researching alternate fibre-forming mineral materials, e.g., asbestos tailings and diopside. The various types and grades of mineral wool and typical raw mineral materials
are identified and reviewed as are the major mineral woolforming processes, furnaces and fiberization methods. Glass fibre properties and fundamental considerations of the nature of glass and glass fibre are then reviewed following which the mechanics of chemical attack on glasses in aqueous
solutions is considered. Finally, alkali-resistant fibres are reviewed and alkali-resistant evaluation tests described.
On the determination of the lattice type and unit cell parameters of a crystal using electron diffraction
Authors: Milliken K S
Published: April 2018

The goniometer stage of a Philips EM300 transmission electron microscope has been used as a measuring device in lattice determination. Hewlett-Packard 9810A programs have been written to control the lattice calculations. The use of the programs is described and
two examples are given.
Comparison of notch-ductility and weldability of three high-strength structural steels
Authors: Campobell W P
Published: April 2018

A comparative study was made of the tensile, Charpy Vnotch, and drop-weight properties of prime plate and welds in commercially produced T-1 and CET-100 steels and in an experimental Cu-Ni steel which was produced commercially but with further laboratory
processing. Comparison was also made of the cold-cracking behaviour of weld heat-affected zones in the three steels and of the behaviour of welds in explosion-bulge tests. Confirmatory crack-starter explosion-bulge tests were made on the Cu-Ni prime plate. Prime plate tensile properties exceeding
those of ASTM specification A517 were met by the three steels, and transverse weld tensile strengths exceeded the prime plate strengths. The highest prime plate Charpy V-notch ductility was developed by the Cu-Ni steel and the lowest by the CHT-100 steel. This relative rating was confirmed by the
drop-weight results. Charpy V-notch properties of welds in each steel equalled or exceeded those of the corresponding plate. The drop-weight results, also for weld centre-line locations, were generally supportive of the Charpy V-notch results for welds, although considerable difficulty was
experienced with anomalous or secondary cracking in the crackstarter bead of many drop-weight specimens. This anomalous cracking was investigated to determine its cause and possible remedy. Welds in T-1 and Cu-Ni steels showed consistently good performance in the explosion-bulge tests at
temperatures down to -32°C (-25°F), but welds in CHT-100 steel demonstrated inconsistent performance ranging from good to poor at temperatures up to -1°C (30°F). The crack-starter explosion-bulge tests on Cu-Ni steel confirmed earlier results of a crack-arrest temperature at or
close to -46°C (-51°F). In the comparative heat-affected zone cold-cracking studies, the three steels showed no tendency to crack in Controlled Thermal Severity tests, but all cracked severely in Y-groove butt weld restraint tests unless preheating was employed. The Cu-Ni and CHT-100
steels required a slightly higher preheat level than did the T-1 steel to eliminate cracking.
Fluorite
Authors: Collings R K , Andrews P R A
Published: April 2018

More than 300 occurrences or deposits of fluorite (calcium fluoride, CaF2) have been recorded in Canada; however, deposits of economic significance are confined largely to Newfoundland, Nova Scotia, Ontario and British Columbia. There is only one producer at
present, Minworth Ltd., with a mine and concentrator near St. Lawrence on the Burin Peninsula of Newfoundland. Fluorite occurs in the form of vein, replacement and residual deposits; vein deposits predominate and form the chief source of commercial fluorite. Although some deposits are relatively
high grade, most require beneficiation. Beneficiation commonly includes gravity separation, e.g., jigging and tabling, magnetic separation and flotation. Fluorite has important uses in the chemical, metallurgical and ceramic industries, and is produced in three grades acid, metallurgical and
ceramic to supply industry requirements. Fluorite has been the subject of many laboratory studies by CANMET and other organizations. This report references 31 fluorite studies by CANMET and nine by others. Summaries of the most important CANMET studies are presented in the
Appendix.
Completeness of the Road-to-Health Booklet and Road-to-Health Card: Results of cross-sectional surveillance at a provincial tertiary hospital
Authors: Naidoo Harishia , Avenant Theunis , Goga Ameena
Published: April 2018

Background: Accurate record-keeping is important for continuity and quality of care. Completing a child’s Road-to-Health Booklet (RTHB), or the older, less detailed, Road-to-Health Card/Chart (RTHC), immediate interpretation thereof and appropriate action facilitates comprehensive care, which could contribute to a decline in child morbidity and mortality.Objective: This study aimed to assess the extent to which healthcare personnel working in catchment clinics of Kalafong Provincial Tertiary Hospital (KPTH), Tshwane district, South Africa, complete HIV-related, sociodemographic, neonatal, growth and immunisation information in the RTHC and/or RTHB.Methods: A cross-sectional, quantitative record review was conducted. Data were extracted from 318 RTHCs and/or RTHBs of children attending KPTH for paediatric care. Data extraction focused on six main areas, namely documentation of HIV-related, neonatal, sociodemographic, anthropometric, immunisation and vitamin A-related information. During data analysis, age-appropriate completeness scores were generated for each area and completeness of documentation in the RTHB and RTHC was assessed.Results: Data demonstrate significantly less unrecorded HIV-related information (maternal HIV status, timing of maternal HIV testing, timing of maternal antiretroviral therapy [ART] initiation, current maternal ART use and infant feeding decisions) in RTHBs compared with RTHCs (p < 001). Despite this, 24% of all RTHBs had no record of maternal HIV status and 67% of RTHBs from documented HIV-exposed infants had no record of maternal ART duration. Neonatal information completeness was similar between RTHBs and RTHCs, but socio-demographic completeness was significantly better in RTHBs compared with RTHCs (p = 0.006). Growth (especially weight), immunisation and vitamin A completeness was > 80% and similar between RTHBs and RTHCs. Length-for-age, weight-for-length and head circumference were plotted in < 5% of RTHBs and none of the RTHCs.Conclusion: Although completeness of key HIV-related information was better in RTHBs compared with RTHCs, RTHB completeness was suboptimal. Healthcare personnel need reminders to utilise the RTHB optimally to improve continuity and quality of child healthcare.
A Morse index invariant reduction of non-equilibrium thermodynamics
Authors: Cardin Franco , Masci Leonardo
Published: April 2018

We consider the finite dimensional reduction of the well known non-equilibrium thermodynamics theory developed through the last two decades by a team of researchers lead by Giovanni Jona-Lasinio, realized by considering a simplified version – a reaction-diffusion-like dynamics – of that theory. We begin with a clear axiomatic format of that framework, showing that the reaction-diffusion dynamics emerge in a direct way after a few assumptions. Our goal is to put focus on the relations between the reduced and the full theory and to underline some topological features of this theory, more precisely, by first showing that the Morse index distribution of the equilibria of the finite dimensional reduced system is exactly the same of the full original system, thus giving us eventually a good measure of the robustness of the reduction, and secondly, moving our framework to a Morse–Smale setting, by proposing an alternative way to compute the Morse index of the equilibria. In order to realize this last program, we propose a weak infinite-dimensional Maslov–Hörmander theorem.
A continuum model of interlocking structural systems
Authors: Brocato Maurizio
Published: April 2018

Masonry systems made of interlocking square-cut stones have long been studied by mathematicians and architects. It so happens that, under appropriate boundary conditions, ashlars interlock, and a stable structure results. Recently, the idea that new masonry-like materials can be designed on the basis of this archetypal principle has been put forward and applications have been proposed under the name of topological interlocking materials.

In this paper, a mathematical model is proposed, that describes these materials as a special class of continua with microstructure. The system is viewed as a continuous body, the material elements of which are ashlar blocks endowed with an interaction structure based, to within certain approximations, on their interlocking geometry. The case of rigid ashlars with purely plastic interactions is developed in detail.
On Professor Grioli’s last riddle: What boundary and initial conditions make sense for microstructured continua?
Authors: Podio-Guidugli Paolo
Published: April 2018

An abridged but faithful exposition of Professor Grioli’s version of the theory of microstructured continua of Cosserat type is given, so as to reformulate and discuss the title question. This exposition prompts some reflections on how to bridge by the use of continuum theories the gap between microscopic and macroscopic mathematical descriptions of matter.
Compactness and $s$-numbers for polynomials
Authors: Çalışkan Erhan , Rueda Pilar
Published: April 2018

We extend the measure of non compactness notion to the polynomial setting by means of Approximation, Kolmogorov and Gelfand numbers, that are introduced for homogeneous polynomials. As an application, we study diagonal polynomials between sequence spaces.
On a $(p,q)$-Laplacian problem with parametric concave term and asymmetric perturbation
Authors: Marano Salvatore A. , Mosconi Sunra J.N. , Papageorgiou Nikolaos S.
Published: April 2018

A Dirichlet problem driven by the

(p,q)

-Laplace operator and an asymmetric concave reaction with positive parameter is investigated. Four nontrivial smooth solutions (two positive, one negative, and the remaining nodal) are obtained once the parameter turns out to be suffciently small. Under a oddness condition near the origin for the perturbation, a whole sequence of sign-changing solutions, which converges to zero, is produced.
Inverse mean curvature flow in quaternionic hyperbolic space
Authors: Pipoli Giuseppe
Published: April 2018

In this paper we complete the study started in [Pi2] of evolution by inverse mean curvature flow of star-shaped hypersurface in non-compact rank one symmetric spaces. We consider the evolution by inverse mean curvature flow of a closed, mean convex and star-shaped hypersurface in the quaternionic hyperbolic space. We prove that the flow is defined for any positive time, the evolving hypersurface stays star-shaped and mean convex. Moreover the induced metric converges, after rescaling, to a conformal multiple of the standard sub-Riemannian metric on the sphere defined on a codimension 3 distribution. Finally we show that there exists a family of examples such that the qc-scalar curvature of this sub-Riemannian limit is not constant.
Eigenvalue problem for fractional Kirchhoff Laplacian
Authors: Tyagi Jagmohan
Published: April 2018

In this note, we discuss the isolatedness, simplicity and nodal estimate for the first eigenvalue of fractional Laplacian of Kirchhoff type. This work is motivated by the recent works on the fractional eigenvalues.
Prevalence of Depressive Symptoms and Related Risk Factors among Patients with Tuberculosis in China: A Multistage Cross-Sectional Study
Authors: Gong Yanhong , Yan Shijiao , Qiu Lei , Zhang Shengchao , Lu Zuxun , Tong Yeqing , Fang Pengqian , Yin Xiaoxv
Published: April 2018

Poor mental health among tuberculosis (TB) patients affects not only their compliance with treatments but also their daily lives. Few studies in China have evaluated depressive symptoms among TB patients. The present study aimed to determine the prevalence of depressive symptoms and its associated risk factors among Chinese TB patients. A total of 1,342 TB patients were recruited using a multistage sampling method and interviewed using a structured questionnaire. Depressive symptoms were measured using the Center for Epidemiologic Studies Depression Scale. Multinomial logistic regression analysis was performed to identify risk factors of depressive symptoms. Of the 1,342 participants included in this study, 48.0% had depressive symptoms. Of these, 34.8% and 13.2% had mild and moderate-to-severe depressive symptoms, respectively. Factors associated with depressive symptoms included family dysfunction, TB-related stigma, poor doctor–patient communication, and lack of knowledge about TB. Depressive symptoms are common among TB patients in China. Efforts of government and stakeholders in the development of relevant policy documents to prevent stigma and create social support for TB patients are necessary. This would not only promote their mental health but also improve their compliance with treatments.
Polskie badania polarne (zarys)
Authors: Birkenmajer Krzysztof Ludwik
Published: April 2018

Artykuł przedstawia w skrócie najważniejsze fakty z historii polskich badań i odkryć naukowych w Arktyce i Antarktyce od XIX stulecia do chwili obecnej. Autor jest geologiem, od 1956 roku badaczem polarnym, prowadził badania naukowe i zorganizował 23 wyprawy polarne na Spitsbergen, Grenlandię i do Antarktyki, przez wiele lat był przewodniczącym Komitetu Badań Polarnych przy Prezydium Polskiej Akademii Nauk. Obecnie jest jego honorowym przewodniczącym.
Communist anniversaries as a symphony of power and science (case study of Bulgaria)
Authors: Drzewiecka Ewelina
Published: April 2018

The aim of the paper is to show the interplay between the power and the science in the context of cultural memory. The focus is on the Cyrillo-Methodian anniversaries in Bulgaria in the communist period, and the object of the analysis is the anniversary of 1969. The context relates to the process of development of new historiography and the functionalization of the nation-centric narrative. The main issue discussed is how the Communist Party, as a political institution, and the Bulgarian Academy of Science, as an academic institution, cooperated to establish a new vision of society. The discussion offers an interpretation in the light of the Orthodox concept of the symphony of power perceived as a metaphor of the relation between the secular and the spiritual power.
The concepts of Ludwik Fleck and their application to the eukaryotic cell cycle
Authors: Cooper Stephen
Published: April 2018

The concepts of Ludwik Fleck (1896–1961), a microbiologist, historian, and philosopher of medicine, can be used to analyze the conservative nature of scientific ideas. This is discussed and applied to ideas dominant in the understanding of the eukaryotic cell cycle. These are (a) the G1-phase restriction point as a regulatory element of the mammalian cell cycle, (b) the Rate Change Point proposed to exist in fission yeast, and (c) the proposal that a large number of genes are expressed in a cell-cycle-dependent manner.Fleck proposed that scientific ideas become fixed and difficult to change because criticisms of current and dominant models are either ignored or turned to support of the current model. The idea of a thought-collective leading to the stability of scientific ideas is a central theme of the theory of Ludwik Fleck.
Uwagi na temat „Projektu z dnia 23 marca 2017 r. Rozporządzenie Ministra Nauki i Szkolnictwa Wyższego z dnia ………… 2017 r.”
Authors: Kokowski Michał
Published: April 2018

Artykuł omawia „Projekt z dnia 23 marca 2017 r. Rozporządzenie Ministra Nauki i Szkolnictwa Wyższego z dnia ………… 2017 r.”, wskazuje wady natury legislacyjnej i naukoznawczej (w tym bibliometrycznej) tego projektu oraz postuluje istotną nowelizację treści tego rozporządzenia.
Ludwik Fleck. Tradycje – inspiracje – interpretacje (red. Bożena Płonka-Syroka, Paweł Jarnicki, Bogdan Balicki). Wrocław: Wydawnictwo Fundacji „Projekt Nauka”, 2015, ss. 313
Authors: Rydlewski Michał
Published: April 2018

Artykuł krytycznie omawia zbiór tekstów poświęconych lwowskiemu mikrobiologowi i teoretykowi poznania naukowego – Ludwikowi Fleckowi. Artykuł przedstawienia główne tezy tekstów oraz merytorycznie ustosunkowuje się do nich, niekiedy podejmując polemikę.
Some categorical aspects of the inverse limits in ditopological context
Authors: Yildiz Filiz
Published: April 2018

This paper considers some various categorical aspects of the inverse systems (projective spectrums) and inverse limits described in the category ifPDitop, whose objects are ditopological plain texture spaces and morphisms are bicontinuous point functions satisfying a compatibility condition between those spaces. In this context, the category InvifPDitop consisting of the inverse systems constructed by the objects and morphisms of ifPDitop, besides the inverse systems of mappings, described between inverse systems, is introduced, and the related ideas are studied in a categorical - functorial setting. In conclusion, an identity natural transformation is obtained in the context of inverse systems - limits constructed in ifPDitop and the ditopological infinite products are characterized by the finite products via inverse limits.
Trends in air pollutants and health impacts in three Swedish cities
over the past three decades
Authors: Olstrup Henrik , Forsberg Bertil , Orru Hans , Spanne Mårten , Nguyen Hung , Molnár Peter , Johansson Christer
Published: April 2018

Abstract. Air pollution concentrations have been decreasing in many cities in the developed countries. We have estimated time trends and health effects associated with exposure to NOx, NO2, O3, and PM10 in the Swedish cities of Stockholm, Gothenburg, and Malmo from the 1990's to 2015. Trend analyses of concentrations have been performed by using the Mann-Kendall test and the Theil-Sen method. Measured concentrations are from central monitoring stations representing urban background levels, and they are assumed to indicate changes in long-term exposure to the population. However, corrections for population exposure have been performed for NOx, O3, and PM10 in Stockholm, and for NOx in Gothenburg. For NOx and PM10, the concentrations at the central monitoring stations are shown to overestimate exposure when compared to dispersion model calculations of spatially resolved population-weighted exposure concentrations, while the reverse applies to O3. The trends are very different for the pollutants that are studied; NOx and NO2 have been decreasing in all cities, O3 exhibits an increasing trend in all cities, and for PM10, there is a slowly decreasing trend in Stockholm, a slowly increasing trend in Gothenburg, and no significant trend in Malmo. When the trends are divided into weekdays and weekends, the decreasing trends associated with NOx and NO2 are more prominent during weekdays compared to weekends, indicating that local emission reductions from traffic to a large part have contributed to these declining trends. Health effects in terms of changes in life expectancy are calculated based on the trends in exposure to NOx, NO2, O3, and PM10, and the relative risks associated with exposure to these pollutants. The decreased levels of NOx are estimated to increase the life expectancy by up to 11 months for Stockholm and 12 months for Gothenburg. This corresponds to up to one fifth of the total increase in life expectancy (54–70 months) in the cities during the period 1990–2015. In contrast to NOx and NO2, the changing trends associated with O3 and PM10 have relatively little impact on the change in life expectancy. NOx and NO2 are highly associated with vehicle exhaust emissions, indicating that decreasing road-traffic emissions have had significant impact on the public health in these cities.
The impact of data assimilation on the prediction of Asian desert dust using an operational 4D-Var system
Authors: Benedetti Angela , Di Giuseppe Francesca , Jones Luke , Peuch Vincent-Henri , Rémy Samuel , Zhang Xiaoye
Published: April 2018

Abstract. Asian Dust is a seasonal meteorological phenomenon which affects East Asia, and has severe consequences on the air quality of China, North and South Korea and Japan. Despite the continental extent, the prediction of severe episodes and the anticipation of their consequences is challenging. Three one-year experiments were run to assess the skill of the model of the European Centre for Medium-Range Weather Forecasts (ECMWF) in monitoring Asian dust and understand its relative contribution to air quality over China. Data used were the MODIS Dark Target and the Deep Blue Aerosol Optical Depth. In particular the experiments aimed at understanding the added value of data assimilation runs over a model run without any aerosol data. The year 2013 was chosen as representative for the availability of independent Aerosol Optical Depth (AOD) data from two established ground-based networks (AERONET and CARSNET), which could be used to evaluate experiments. Particulate Matter (PM) data from the China Environmental Protection Agency (CEPA) were also used in the evaluation. Results show that the assimilation of satellite AOD data is beneficial to predict the extent and magnitude of desert-dust events and to improve the forecast of such events. The availability of observations from the MODIS Deep Blue algorithm over bright surfaces is an asset, allowing for a better localization of the sources and definition of the dust events. In general both experiments constrained by data assimilation perform better that the unconstrained experiment, generally showing smaller mean normalized bias and fractional gross error with respect to the independent verification datasets. The impact of the assimilated satellite observations is larger at analysis time, but lasts well into the forecast. While assimilation is not a substitute for model development and characterization of the emission sources, results indicate that it can play a big role in delivering improved forecasts of Asian Dust.
Enhancing the consistency of spaceborne and ground-based radar comparisons by using quality filters
Authors: Crisologo Irene , Warren Robert , Mühlbauer Kai , Heistermann Maik
Published: April 2018

Abstract. Coinciding monsoon and typhoon seasons in the Philippines cause torrential rainfall, and associated hazards such as flooding and landslides. While early warning systems require accurate radar-based rainfall estimates, low-density rain gauge networks in the Philippines make it challenging to monitor the calibration of the ground-based radars (GRs). As an alternative, we explore the potential of spaceborne radar (SR) observations from the Ku-band precipitation radars on board the TRMM and GPM satellites as a reference to quantify the calibration bias of an S-band GR in the Philippines. To this end, the 3D volume-matching algorithm proposed by Schwaller and Morris (2009) is implemented and applied to five years (2012–2016) of observations. We further extend the procedure by a framework to take into account the data quality of each ground radar bin. Through these methods, we are able to assign a quality index to each matching SR-GR volume, and thus compute the GR calibration bias as a quality-weighted average of reflectivity differences in any sample of matching GR-SR volumes. We exemplify the idea of quality-weighted averaging by using the beam blockage fraction as a basis of a quality index. As a result, we can increase the consistency of SR and GR observations, and thus the precision of calibration bias estimates. The remaining scatter between GR and SR reflectivity, as well as the variability of bias estimates between overpass events indicate, however, that other error sources are not yet fully addressed. Still, our study provides a framework to introduce any other quality variables that are considered relevant in a specific context. The code that implements our analysis is based on the open source software library wradlib, and is, together with the data, publicly available to monitor radar calibration, or to scrutinize long series of archived radar data back to December 1997, when TRMM became operational.
Interpreting eddy covariance data from heterogeneous Siberian tundra: land cover-specific methane fluxes and spatial representativeness
Authors: Tuovinen Juha-Pekka , Aurela Mika , Hatakka Juha , Räsänen Aleksi , Virtanen Tarmo , Mikola Juha , Ivakhov Viktor , Kondratyev Vladimir , Laurila Tuomas
Published: April 2018

Abstract. The non-uniform spatial integration inherent in the eddy covariance (EC) method provides an additional challenge for data interpretation when fluxes are measured in a heterogeneous environment, as the contribution of different surface types varies with flow conditions, potentially resulting in a bias as compared to the true areally averaged fluxes and surface attributes. We modelled flux footprints and characterized the spatial scale of our EC measurements at Tiksi, a tundra site in northern Siberia, including a comparison of different source area definitions. We used leaf area index (LAI) and land cover class (LCC) data, derived from very high spatial resolution satellite imagery and field surveys, and quantified the sensor location bias. We found that methane (CH4) fluxes varied strongly with wind direction (from −0.09 to 0.59 μg m−2 s−1 on average), reflecting the distribution of different LCCs. Using footprint weights of grouped LCCs as explanatory variables for the measured CH4 flux, we then developed a multiple regression model to estimate LCC-specific fluxes. This model showed that wet fen and graminoid tundra patches in locations with a high topography-based wetness index acted as strong CH4 sources (0.95 μg m−2 s−1), while mineral soils were significant sinks (−0.13 μg m−2 s−1). Finally, to assess the representativeness of CH4 flux measurements, we upscaled the LCC-specific fluxes to different spatial scales. This assessment showed that, despite the surface heterogeneity and rather poor representativeness of EC data with respect to the areally averaged LAI and coverage of some LCCs, the mean CH4 flux measured during summer 2014 was close to the corresponding balance upscaled to an area of 6.3 km2, with a location bias of 14 %. We recommend that EC site descriptions in a heterogeneous environment should be complemented with footprint-weighted high-resolution data on vegetation and other relevant site characteristics.
Reviews and syntheses: 210Pb-derived sediment and carbon
accumulation rates in vegetated coastal ecosystems: setting the
record straight
Authors: Arias-Ortiz Ariane , Masqué Pere , Garcia-Orellana Jordi , Serrano Oscar , Mazarrasa Inés , Marbà Núria , Lovelock Catherine E. , Lavery Paul , Duarte Carlos M.
Published: April 2018

Abstract. Vegetated coastal ecosystems, including tidal marsh, mangrove and seagrass, are being increasingly assessed for their potential in carbon dioxide sequestration worldwide. However, there is a paucity of studies that have effectively estimated the accumulation rates of sediment organic carbon (Corg) beyond the mere quantification of Corg stocks. Here, we discuss the use of the 210Pb dating technique as a practical tool to measure the rate of Corg accumulation in vegetated coastal ecosystems. We critically review the status of 210Pb dating methods of vegetated coastal sediments and assess the limitations that apply to these ecosystems, which are often composed by heterogeneous sediments, abundant in coarse particles, with varying inputs of organic material, and are disturbed by natural and anthropogenic processes causing sediment mixing, changes in sedimentation rates or erosion. Through a range of simulations, we discuss the most relevant processes that impact the 210Pb record in vegetated coastal ecosystems and evaluate the deviations in sediment and Corg accumulation rates produced by anomalies in 210Pb profiles. Our results show that the deviation in the determination of sediment and derived Corg accumulation rates is within 20 % confirming that the 210Pb dating technique is secure. However, while these uncertainties might be acceptable for the determination of mean sediment and Corg accumulation rates over the last century, they may not always allow the determination of a detailed geochronology, historical reconstruction, or to ascertain rates of change and fluxes. Additional tracers or geochemical data need to be used in concert to constrain the 210Pb-derived results and to properly interpret the processes recorded in vegetated coastal sediments. The framework provided in this study can be instrumental in reducing the uncertainties associated to the estimates of Corg accumulation rates in vegetated coastal sediments.
Combining Data from the Distributed GRUAN Site Lauder-Invercargill, New Zealand, to Provide a Site Atmospheric State Best Estimate of Temperature
Authors: Tradowsky Jordis S. , Bodeker Gregory E. , Querel Richard R. , Builtjes Peter J. H. , Fischer Juergen
Published: April 2018

Abstract. A Site Atmospheric State Best Estimate (SASBE) of the temperature profile above the GCOS (Global Climate Observing System) Reference Upper-Air Network (GRUAN) site at Lauder, New Zealand, has been developed. Data from multiple sources are combined within the SASBE to generate a high temporal resolution data set that includes an estimate of the uncertainty on every value. The SASBE has been developed to enhance the value of measurements made at the distributed GRUAN site at Lauder and Invercargill (about 180 km apart), and to demonstrate a methodology which can be adapted to other distributed sites. Within GRUAN, a distributed site consists of a cluster of instruments at different locations. The temperature SASBE combines measurements from radiosondes and automatic weather stations at Lauder and Invercargill, and ERA5 reanalysis, which is used to calculate a diurnal temperature cycle to which the SASBE converges in the absence of any measurements. The SASBE provides hourly temperature profiles at 16 pressure levels between the surface and 10 hPa for the years 1997 to 2012. Every temperature value has an associated uncertainty which is calculated by propagating the measurement uncertainties, the ERA5 ensemble SDs, and the ERA5 representativeness uncertainty through the retrieval chain. The SASBE has been longterm archived and obtained the following digital object identifier (doi): doi:10.5281/zenodo.1195779 The study demonstrates a method to combine data collected at distributed sites. The resulting best-estimate temperature data product for Lauder is expected to be valuable for satellite and model validation as measurements of atmospheric essential climate variables are sparse in the Southern Hemisphere. The SASBE could, for example, be used to constrain a radiative transfer model to provide top-of-the-atmosphere radiances with traceable uncertainty estimates.
Geomorphic regulation of floodplain soil organic carbon concentration in watersheds of the Rocky and Cascade Mountains, USA
Authors: Scott Daniel N. , Wohl Ellen E.
Published: April 2018

Abstract. Mountain rivers have shown the potential for high organic carbon (OC) storage in terms of retaining OC-rich soil. We characterize valley bottom morphology, floodplain soil, and vegetation in two disparate mountain river basins: the Middle Fork Snoqualmie, in the Cascade Mountains, and the Big Sandy, in the Wind River Range of the Rocky Mountains. We use this dataset to examine variability in OC concentration between these basins as well as within them, at multiple spatial scales. We find that although there are some differences between basins, much of the variability in OC concentration is due to local factors, such as soil moisture and valley bottom geometry. From this, we conclude that local factors likely play a dominant role in regulating OC concentration in valley bottoms, and that inter-basin trends in climate or vegetation characteristics may not translate directly to trends in OC storage. We also use analysis of OC concentration and soil texture by depth to infer that OC is input to floodplain soils mainly by decaying vegetation, not overbank deposition of fine, OC-bearing sediment. Geomorphology and hydrology play strong roles in determining the spatial distribution of soil OC in mountain river corridors.
MPAS-Albany Land Ice (MALI): A variable resolution ice sheet
model for Earth system modeling using Voronoi grids
Authors: Hoffman Matthew J. , Perego Mauro , Price Stephen F. , Lipscomb William H. , Jacobsen Douglas , Tezaur Irina , Salinger Andrew G. , Tuminaro Raymond , Zhang Tong
Published: April 2018

Abstract. We introduce MPAS-Albany Land Ice (MALI), a new, variable resolution land ice model that uses unstructured Voronoi grids on a plane or sphere. MALI is built using the Model for Prediction Across Scales (MPAS) framework for developing variable resolution Earth System Model components and the Albany multi-physics code base for solution of coupled systems of partial-differential equations, which itself makes use of Trilinos solver libraries. MALI includes a three-dimensional, first-order momentum balance solver ("Blatter-Pattyn") by linking to the Albany-LI ice sheet velocity solver, as well as an explicit shallow ice velocity solver. Evolution of ice geometry and tracers is handled through an explicit first-order horizontal advection scheme with vertical remapping. Evolution of ice temperature is treated using operator splitting of vertical diffusion and horizontal advection and can be configured to use either a temperature or enthalpy formulation. MALI includes a mass-conserving subglacial hydrology model that supports distributed and/or channelized drainage and can optionally be coupled to ice dynamics. Options for calving include "eigencalving", which assumes calving rate is proportional to extensional strain rates. MALI is evaluated against commonly used exact solutions and community benchmark experiments and shows the expected accuracy. We report first results for the MISMIP3d benchmark experiments for a Blatter-Pattyn type model and show that results fall in-between those of models using Stokes flow and L1L2 approximations. We use the model to simulate a semi-realistic Antarctic Ice Sheet problem for 1100 years at 20 km resolution. MALI is the glacier component of the Energy Exascale Earth System Model (E3SM) version 1, and we describe current and planned coupling to other components.
Controls on spatial and temporal variability of streamflow and hydrochemistry in a glacierized catchment
Authors: Engel Michael , Penna Daniele , Bertoldi Giacomo , Vignoli Gianluca , Tirler Werner , Comiti Francesco
Published: April 2018

Abstract. The understanding of the hydrological and hydrochemical functioning of glacierized catchments require the knowledge of the different controlling factors and their mutual interplay. For this purpose, the present study was carried out in two sub-catchments of the Sulden River catchment (130 km2, Eastern Italian Alps) in 2014 and 2015, characterized by similar size but contrasting geological setting. Samples were taken at different space and time scales for analysis of stable isotopes of water, electrical conductivity, major, minor and trace elements. At the monthly sampling scale for different spatial scales (0.05–130 km2), complex spatial and temporal dynamics such as contrasting EC gradients in both sub-catchments were found. At the daily scale, for the entire Sulden catchment the relationship between discharge and electrical conductivity showed a monthly hysteretic pattern. Hydrometric and geochemical dynamics were controlled by an interplay of meteorological conditions and geological heterogeneity. After conducting a PCA analysis, the largest share of variance (36.3 %) was explained by heavy metal concentrations (such as Al, V, Cr, Ni, Zn, Cd, Pb) during the melting period while the remaining variance (16.3 %) resulted from the bedrock type in the upper Sulden sub-catchment (inferred from EC, Ca, K, As and Sr concentrations). Thus, high concentrations of As and Sr in rock glacier outflow may more likely result from bedrock weathering. Furthermore, nivo-meteorological indicators such as maximum daily global solar radiation, three day maximum air temperature, and 15 day snow depth differences could explain the monthly conductivity and isotopic dynamics best. The decrease of snow depth calculated for different time lengths prior to the sampling day showed best agreements with conductivity and isotopic dynamics when time lengths varied. These insights may help to better predict hydrochemical catchment responses linked to meteorological and geological controls and to guide future classifications of glacierized catchments according to their hydrochemical characteristics.
Global Phosphorus Recovery for Agricultural Reuse
Authors: Kok Dirk-Jan D. , Pande Saket , van Lier Jules B. , Ortigara Angela R. C. , Savenije Hubert , Uhlenbrook Stefan
Published: April 2018

Abstract. Phosphorus is is an element necessary for the development of crops and is thus commonly applied as fertilizer to sustain agricultural production. It occurs naturally at indefinite quantities, of uncertain quality, in phosphate rock formations, but also concentrates itself in urban and livestock wastewater wherefrom it is often lost as a pollutant. Recovering phosphorus from wastewater to partially meet agricultural demand can contribute to tackling both phosphorus pollution as well natural resource depletion. Here we show that humans discharge a maximum of 3.7 Mt P into wastewater thereby potentially satisfying 20 % of the global fertilizer demand. Provided 2015 market dynamics, however, we conclude that only 4 % of this throughput is technologically and economically recoverable while rock phosphate products exist. Nonetheless, through this recovery many wastewater treatment facilities can contribute to creating sustainable communities as well as protecting the environment, while reducing their own operational cost.
La simplicidad en el diseño de marcas gráficas: análisis de la preferencia
Authors: Suárez-Carballo Fernando , Galindo-Rubio Fernando , Martín-Sanromán J. Ramón
Published: April 2018

Un gran número de autores y profesionales alude a la simplicidad como uno de los atributos fundamentales en la definición del buen diseño; sin embargo, cabe preguntarse por la percepción del público ante este rasgo visual. A partir de una experiencia piloto previa, el presente estudio busca analizar la respuesta del destinatario ante la simplicidad o la complejidad -su técnica opuesta- en el ámbito de la identidad visual, concretamente. La  investigación realiza una descripción previa de ambos conceptos mediante cinco variables y recurre al índice de Preferencia como herramienta para evaluar la reacción del receptor. Siguiendo este modelo, y mediante la valoración del rediseño de 30 identificadores reales por parte de 1304 participantes, el trabajo concluye que existe una significativa inclinación hacia la simplicidad, que se incrementa notablemente en la medida en que el vínculo del sujeto con el diseño gráfico (en cuanto a perfil profesional, formación y conocimientos) es más estrecho.
Trayectorias laborales y competencias de empleabilidad de jóvenes nacionales e inmigrantes en riesgo de exclusión social
Authors: Santana Vega Lidia E. , Alonso Bello Estefanía , Feliciano García Luis
Published: April 2018

Los jóvenes en situación de riesgo de exclusión presentan trayectorias atípicas en las que tienen que hacer frente a la exclusión y la marginación; de ahí la necesidad de que adquieran competencias para la empleabilidad.  La adquisición de tales competencias facilitará a estos jóvenes la obtención y mantenimiento de un empleo y les abrirá las puertas al aprendizaje permanente. Los objetivos del trabajo son: a) analizar las competencias de empleabilidad de los jóvenes nacionales e inmigrantes que salen del sistema público de protección y b) comparar sus trayectorias laborales. Se realizó un estudio de casos múltiples en el que participaron cuatro jóvenes nacionales y cuatro jóvenes inmigrantes subsaharianos no acompañados en riesgo de exclusión, los tutores de sus centros y los empresarios que tutorizaron sus prácticas profesionales. La selección de los casos tuvo en cuenta tres criterios: 1) haber estado acogido al sistema de protección, 2) haber estado un mínimo de 6 meses en un programa de inserción laboral y 3) tener entre16-25 años. Los datos del estudio fueron obtenidos mediante técnicas e instrumentos cualitativos y cuantitativos. Los resultados ponen  de manifiesto que los jóvenes inmigrantes: a) elaboran proyectos de vida más claros y reales que los jóvenes nacionales; b) finalizan su programa de inserción sociolaboral con un mayor nivel de competencias de empleabilidad; c) afrontan su transición a la vida adulta con una mejor formación. Según los datos de la investigación, los jóvenes inmigrantes afrontan de forma más exitosa la transición a la vida adulta que los jóvenes nacionales. En el artículo se discute la necesidad de trabajar sobre los objetivos del proyecto de vida de los jóvenes en riesgo de exclusión, sus redes de apoyo y sus competencias de empleabilidad para ir consolidando sus trayectorias laborales.