bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of Aluminum Nanopowder for Pure Hydrogen Production
Authors: Ilyin Alexander P. , Root Liudmila O. , Mostovshchikov Andrei V.
Published: September 2016

The problems of hydrogen energetic as well as a method of high pure hydrogen obtaining are presented in the paper. It was suggested to use the reaction of aluminium nanopowder with water, as the reaction proceeds with high rate even at ambient conditions (the rate of hydrogen emission reached 18 ml/(s∙g)) and high degree of conversion (up to 100 %). The unreasonableness of the replacement of aluminium nanopowder to coarse-grained powder in this reaction due to the low efficiency is shown in the article. As a solution for pure hydrogen obtaining, a phenomenon of self-heating of aluminum nanoparticles and the resulting hydrogen, as well as the effect of its high-temperature diffusion through the membrane of ultrahigh molecular weight polyethylene were used.
Thermal Hardening of the Tin Bronze Alloyed with Nickel
Authors: Klochkov N.S. , Egorov U.P. , Utyev Oleg M.
Published: September 2016

The article represents the results of thermal hardening of the stannic bronze alloyed with nickel without quenching. The samples were obtained by molding into a metal form applying centrifugal way of molding. Metallographic and phase analyses were carried out to define the mechanism of thermal hardening. The aging mode was chosen to ensure the maximum hardness of stannic bronze with nickel additives of the chosen structure.
3D AlOOH/Fe Micro/Nanostructures: Facile Synthesis, Characterization and Application for Arsenic Removal
Authors: Bakina Olga V. , Glazkova Elena A. , Svarovskaya Natalia V. , Berenda Andrei V. , Lerner Marat I.
Published: September 2016

Novel 3D AlOOH/Fe micro/nanostructures were successfully synthesized by the reaction of Al/Fe binary metallic nanoparticles with water at 60°C and under atmospheric pressure. Al/Fe binary metallic nanopowder was produced by the method of simultaneous electric explosion of twisted aluminum and iron wires in an argon atmosphere. Produced 3D AlOOH/Fe structures were characterized by TEM, SEM, XRD, EDX, BET, and adsorption capacity towards As (V). The hard framework consisting of both the boehmite nanosheets and the nanosheets enriched with iron provides a large available surface and prevents the aggregation of the micro/nanostructures. The high adsorption capacity of 42 mg g-1 As (V) under static conditions allows obtained 3D AlOOH/Fe micro/nanostructures to be a promising material for the removal of arsenic from contaminated drinking water.
Optical Absorption Peculiarities of Al-Si-N Coatings Produced by Magnetron Sputtering
Authors: Kabyshev Alexandr V. , Konusov Fedor V. , Lauk Alexander L. , Lebedinskiy Alexey M. , Legostaev Victor N. , Smolyanskiy Egor A.
Published: September 2016

In this paper the optical absorption characteristics of Al–Si–N coatings, deposited by magnetron sputtering on the substrates from silicon single crystals and glass were studied. The influence of conditions deposition on optical properties has been determined. The characteristics of interband and exponential absorption are determined by influence of localized states (LS) of defects continuously distributed in the band gap (BG) and reflect the influence on properties of crystalline and amorphous components material of coatings. The interband absorption is realized via the allowed indirect transitions through the optical gap 2.7–2.8 eV and direct transitions through the gap 3.8–3.96 eV. The interrelations between the parameters of interband and exponential absorption are typical for the naterials, whose properties are determined by a static and/or dynamic disordering of the crystal lattice by the defects of a different nature. Maximal average value of the BG width is 4.8–5.1 eV in the scope of semiclassical analysis applied to amorphous and strongly defective materials. The optical parameters of deposited coatings are changed in correlation with a changing of the mechanical characteristics in dependency on the nitrogen pressure.
Testing of Plasticity of Protective Coatings under Pure Bending
Authors: Bakhrunov Konstantin
Published: September 2016

The work presents the results of testing of protective diffusion coatings obtained by circular chrome-aluminizing of nickel-based heat-proof alloys of grades ZhS6U, ZhS26U and ZhS32. A technique for testing plasticity of protective coatings under pure bending was suggested.
Application of 3D Сomputed Microtomography for Investigating the Microstructural Defects of Carbon Fiber Reinforced Composite Made by 3D-Printing
Authors: Filippov Andrey V. , Rubtsov Valery E. , Tarasov Sergei Yu. , Beloborodov Vladimir A.
Published: September 2016

The microstructural defect of additive manufactured 3-component carbon fiber reinforced polymer (CFRP) composites has been studied using computed microtomography. The samples have been prepared using a 3D-printing process developed at Skolkovo Institute of Science and Technology, Russia. The research procedure has been described and internal defects of the fiber composite material have been detected and analyzed using a 3D image reconstructed from a number of cross section views. The defects larger 50 μm have been detected using the computed microtomography test. Defect-free images and defects typical for this type of composites such as delamination in polymer matrix and between fibers in a bundle, fiber breakage have been obtained.
Temperature Distribution on the Surface of LED Lamps
Authors: Lebedev Sergey M. , Gurin Sergey Yu.
Published: September 2016

In this work, new thermally conductive polymer materials (TCPMs) on the base of polymer/graphite composites for cooling system of LED lamps were developed. Heat sinks for LED lamps were fabricated and investigated. Thermal conductivity and thermal diffusivity for all TCPMs were investigated by thermal analyzers XFA 500 and THB 100. Infrared thermal imager was used to study the temperature distribution of the LED lamps. Experimental and numerical investigations have shown high efficiency of polymer/graphite heat sinks for LED lamps.
Parameters Investigation of Phosphors for Solid State Lighting
Authors: Ryapolova Yuliya V. , Soldatkin Vasily S. , Afonin Kirill N. , Tuev Vasily I. , Vilisov Anatoly A.
Published: September 2016

Five types of phosphors for LED ribbon beam elements in white LED lamps have been studied. The phosphor composition and colorimetric parameters have been researched during the experiment. It is found that the larger and more uniform the grains of the phosphor, the higher the emission efficiency. The most similar in color to the white color coordinates of the sample No. 5 phosphor having also higher brightness compared with samples No. 1 – No. 4.
Luminescence Spectrum of Yttrium Aluminum Garnet Based Phosphors with Initiating by Different Sources of Optical Excitation
Authors: Lisitsyn Viktor M. , Stepanov Sergey , Abdullin Habibula A. , Tulegenova Aida , Ju Yang Yang , Kolomin Viktor
Published: September 2016

This paper reports the quantitative characteristics of photoluminescence of phosphors powders based on yttrium-aluminium garnets. It contains spectra of excitation, spectra of luminescence with initiating through radiation of xenon lamps and chip with a different power, and kinetic characteristics.
Kinetic Model of Pulsed High Current Electron Beam Propagation in the Gas Medium
Authors: Aktaev Nurken E. , Pak Alexander Y.
Published: September 2016

The theoretical model for investigation of the electron beam propagation in the gas medium is developed. The main feature of the model is the possible to analyze the time evolution of the differential current which allows obtaining the energy distribution function of electron. The equations for electromagnetic fields created by the electron beam are the time dependence function. The elastic collision and ionization are considered as a basic interaction processes between beam and gas medium.
Infrared Spectra Investigation of CuO-Al2O3 Precursors Produced by Electrochemical Oxidation of Copper and Aluminum Using Alternating Current
Authors: Usoltseva Natalya , Korobochkin Valery , Dolinina Alesya S. , Ustyugov Alexander M.
Published: September 2016

Joint electrochemical oxidation of copper and aluminum using alternating current (AC) was performed. The electrolysis products were dried on air (method carbonate) and at the residual pressure of 3-5 kPa (oxide method). Cu-Al layered double hydroxide (Cu-Al/LDH) are formed at air carbonization. Oxide method saves copper (I) oxide. Heat treatment causes the decomposition of LDH to CuO and Al2O3 as well as Cu2O oxidation to CuO. Copper-aluminum spinel (CuAl2O4) is the product of solid-phase interaction of copper and aluminum oxides. Infrared spectra revealed that oxide method provides the boehmite dehydration and metal oxides interaction at lower temperature despite the fact that the poorly crystallized copper (II) oxide is formed at LDH decomposition.
Influence of Plasma Assistance on Arc Deposited MoN Coatings
Authors: Krysina Olga , Shugurov Vladimir V. , Koval Nikolay , Prokopenko Nikita
Published: September 2016

The paper reports on a study to optimize the modes of plasma-assisted vacuum arc deposition of molybdenum nitride (MoN) coatings. It is shown that the parameters of plasma assistance influence the coating properties and that varying the ion current ratio in the metal-gas plasma makes possible MoN coatings with high hardness and high wear resistance.
Antigen Targeting to Human HLA Class II Molecules Increases Efficacy of DNA Vaccination
Authors: Grodeland Gunnveig , Fredriksen Agnete Brunsvik , Løset Geir Åge , Vikse Elisabeth , Fugger Lars , Bogen Bjarne
Published: September 2016

It has been difficult to translate promising results from DNA vaccination in mice to larger animals and humans. Previously, DNA vaccines encoding proteins that target Ag to MHC class II (MHC-II) molecules on APCs have been shown to induce rapid, enhanced, and long-lasting Ag-specific Ab titers in mice. In this study, we describe two novel DNA vaccines that as proteins target HLA class II (HLA-II) molecules. These vaccine proteins cross-react with MHC-II molecules in several species of larger mammals. When tested in ferrets and pigs, a single DNA delivery with low doses of the HLA-II–targeted vaccines resulted in rapid and increased Ab responses. Importantly, painless intradermal jet delivery of DNA was as effective as delivery by needle injection followed by electroporation. As an indication that the vaccines could also be useful for human application, HLA-II–targeted vaccine proteins were found to increase human CD4+ T cell responses by a factor of ×103 in vitro. Thus, targeting of Ag to MHC-II molecules may represent an attractive strategy for increasing efficacy of DNA vaccines in larger animals and humans.
Antigen-Specific Immune Modulation Targets mTORC1 Function To Drive Chemokine Receptor–Mediated T Cell Tolerance
Authors: Chen Weirong , Wan Xiaoxiao , Ukah Tobechukwu K. , Miller Mindy M. , Barik Subhasis , Cattin-Roy Alexis N. , Zaghouani Habib
Published: September 2016

To contain autoimmunity, pathogenic T cells must be eliminated or diverted from reaching the target organ. Recently, we defined a novel form of T cell tolerance whereby treatment with Ag downregulates expression of the chemokine receptor CXCR3 and prevents diabetogenic Th1 cells from reaching the pancreas, leading to suppression of type 1 diabetes (T1D). This report defines the signaling events underlying Ag-induced chemokine receptor-mediated tolerance. Specifically, we show that the mammalian target of rapamycin complex 1 (mTORC1) is a major target for induction of CXCR3 downregulation and crippling of Th1 cells. Indeed, Ag administration induces upregulation of programmed death-ligand 1 on dendritic cells in a T cell–dependent manner. In return, programmed death-ligand 1 interacts with the constitutively expressed programmed death-1 on the target T cells and stimulates docking of Src homology 2 domain-containing tyrosine phosphatase 2 phosphatase to the cytoplasmic tail of programmed death-1. Active Src homology 2 domain-containing tyrosine phosphatase 2 impairs the signaling function of the PI3K/protein kinase B (AKT) pathway, leading to functional defect of mTORC1, downregulation of CXCR3 expression, and suppression of T1D. Thus, mTORC1 component of the metabolic pathway serves as a target for chemokine receptor-mediated T cell tolerance and suppression of T1D.
Antigen-Specific Development of Mucosal Foxp3+RORγt+ T Cells from Regulatory T Cell Precursors
Authors: Solomon Benjamin D. , Hsieh Chyi-Song
Published: September 2016

Foxp3+retinoic acid–related orphan receptor (ROR)γt+ T cells have recently been characterized as an immunoregulatory population highly enriched in the colon lamina propria. However, their developmental origin and relationship to RORγt− regulatory T and Th17 cells remain unclear. In this study, we use a fixed TCRβ system to show that the TCR repertoire of the Foxp3+RORγt+ population is mostly distinct compared with other colonic T cell subsets. However, of these TCRs, a fraction is also found in the Th17 subset, suggesting that TCR repertoire overlap may contribute to the reported ability of Foxp3+RORγt+ cells to regulate Th17 immunity. Naive transgenic T cells expressing a Foxp3+RORγt+-restricted TCR first acquire a Foxp3+RORγt− phenotype before coexpressing RORγt, suggesting that Foxp3+RORγt+ cell development can occur via an RORγt− regulatory T cell intermediate.
Political economy and citizen empowerment: Strategies and challenges of Emiratisation in the United Arab Emirates
Authors: Thompson Paul , Wissink Henry
Published: September 2016

Orientation:  The United Arab Emirates’ labour market by design is inclined to exclude generally the Emirati population from active participation in the private sector, in order to take advantage of cheap labour primarily from South Asia.Research purpose: The aim of this article was to explain, using labour market segmentation theory, how the present epoch of free market capitalism in the ‘minority state’ of the United Arab Emirates (UAE) has socially excluded its’ citizens.Motivation for the study:  The pro-national Emiratisation or employment policy project implemented by the federal government in 1998 provided an opportunity for UAE citizens to be fully absorbed in the private and public sectors. Researching the process as it unfolded, insights are unearthed as to why Emirati citizens are still on the periphery of the country’s labour market.Research design, approach and method:  The article employed a qualitative methodology using the UAE as a single case study.Main findings: The research on the UAE’s Emiratisation or labour nationalisation policies found that there are a number of systemic and structural barriers that have hampered the successful implementation of government policies in both the private and public sectors.Practical/managerial implications: Policy makers need to be able to differentiate between the systemic, structural and institutional factors that have stymied government’s attempt at addressing the country’s demographic imbalance and the social exclusion of Emirati citizens from the labour market.Contribution/value-add: This research has filled a gap in literature on the theme, and has also deviated from earlier research findings on the barriers to achieving policy targets.
Interreligious education in the context of Social Psychology research on attitudes and prejudice
Authors: Rothgangel Martin
Published: September 2016

Since the mid-1990s, interreligious education has become an integral component of thereligious education debate. Regardless of the affective level that interreligious education seeksto provide, the desired changes in attitude and prejudice require one to take into account adiversity of research on attitude and prejudice. Accordingly, the goal of the present article is toencourage the adoption of psychological theories of prejudice with a view to the prospectsthey offer to interreligious education. However, because the field of psychological prejudiceresearch is complex, we will only be discussing those theories that, firstly, reflect the presentstate of prejudice psychology and, secondly, are of particular relevance to interreligiouseducation; these are cognitive theories (accentuation theory, illusory correlation theory,attribution theory), the social identity theory, and social learning theory. Emanating from thisreview, the article will go on to reflect different strategies of attitude change for interreligiouslearning.
Supply chain management best practices: A case of humanitarian aid in southern Africa
Authors: Ngwenya Ngonidzahe K. , Naude Micheline J.A.
Published: September 2016

Background: A key contemporary issue in the southern African region is the increased frequency of the number of natural disaster occurrences. Because of the extent of the damage as a result of these disasters, beneficiary needs have to be met to mitigate against consequent hardships and the loss of lives in the affected communities.Objectives: This article reports on a study that investigated supply chain management best practices that are employed by the United Nations World Food Programme’s (UNWFP) when dealing with disasters.Method: This exploratory study consisted of five in-depth interviews with voluntary participants at the UNWFP regional office in Johannesburg to determine the various initiatives adopted by the UNWFP that ensure successful disaster relief operations. Thematic analyses were used to analyse the collected data.Results: Based on the themes generated from the in-depth interviews, supply chain best practices were mainly linked to the concepts of agility, responsiveness and flexibility.Conclusion: The main findings revealed that the strategic planning, implementation and controlling of agile, flexible and responsive supply chain practices can contribute to the success of logistical operations supporting humanitarian efforts in southern Africa.
The effects of job crafting on subjective well-being amongst South African high school teachers
Authors: Peral Sergio , Geldenhuys Madelyn
Published: September 2016

Orientation: Job crafting can result in a number of positive outcomes for teachers, such as increased meaningfulness and engagement at work. Increased work engagement and psychological meaningfulness may yield positive benefits for the practice of teaching, thus highlighting the pivotal role of job crafting.Research purpose: The study’s aim was to investigate the relationship between job crafting and subjective well-being amongst South African high school teachers. Subjective well-being comprises psychological meaningfulness and work engagement. The potential mediating effect that psychological meaningfulness had on this relationship was further explored.Motivation for the study: Being in a highly stressful occupation, teachers need to continuously find ways to craft their working practices in order to deal effectively with their job demands and to capitalise on their available job resources. Furthermore, South Africa’s current education system calls for serious proactive measures to be taken to improve and rectify the current status, such as job crafting.Research approach, design and method: A quantitative, cross-sectional survey design was used and administered to a sample of South African high school teachers situated in Gauteng, South Africa (N = 251).Main findings: A positive relationship was found between job crafting (increasing structural resources and challenging job demands) and work engagement. Furthermore, psychological meaningfulness mediated the relationship between job crafting and work engagement amongst the sampled high school teachers.Practical/managerial implications: Teachers who craft their work to better suit their preferences and needs will obtain greater meaning in their work and experience increased levels of work engagement. Training programmes and/or group-based interventions targeted around job crafting techniques may be particularly useful in the South African teaching context.Contribution/value-add: This study highlights the importance of job crafting to the well-being of teachers. It further contributes to the literature pertaining to job crafting and teaching specifically, as well as to the limited job crafting research that has been conducted in the South African context.
Post-Kala-Azar Dermal Leishmaniasis Without Previous History of Visceral Leishmaniasis
Authors: Hasnain Golam , Shomik Mohammad Sohel , Ghosh Prakash , Rashid Mamun Or , Hossain Shakhawat , Hamano Shinjiro , Mondal Dinesh
Published: September 2016

Post-kala-azar dermal leishmaniasis (PKDL) without previous visceral leishmaniasis (VL) is a rare dermatological manifestation of Leishmania infection. To date, most of the reported cases neither showed parasitological confirmation nor explained the outcome of treatment. Herein, we report three confirmed cases that were were successfully cured after miltefosine treatment.
West Nile Virus Infection in Human and Mouse Cornea Tissue
Authors: Blitvich Bradley J. , Wang Tian , Saxena Vandana , Zeng Shemin , Harmon Karen M. , Raymond Matthew D. , Goins Kenneth M. , Reed Cynthia R. , Mullins Robert F. , Greiner Mark A.
Published: September 2016

The purpose of this study was to determine the in vitro and ex vivo susceptibility of human corneal cells to West Nile virus (WNV) infection and evaluate the ability of the virus to disseminate to the corneas of infected mice. Human corneal epithelial cells were challenged with WNV, incubated for 1–6 days, and tested for evidence of WNV infection. Viral RNA and antigen were detected at every time point, and the virus reached a peak titer of 2.5 × 107 plaque-forming units (pfu)/mL at 3 days postinoculation (PI). Corneas procured from donors were incubated in culture dishes containing WNV for 1–5 days and tested for evidence of WNV. Viral RNA and antigen were detected, and the virus reached a mean peak titer of 4.9 × 104 pfu/mL at 5 days PI. Mice were inoculated intraperitoneally with WNV, and their eyes were harvested at 2, 5, and 8 days PI and tested for evidence of WNV. Viral RNA was detected in corneas of four of nine systemically infected mice as early as 2 days PI. We conclude that human corneal cells support WNV replication in vitro and ex vivo, and WNV may disseminate into the corneas of experimentally infected mice. These findings indicate that corneal transmission cannot be ruled out as a novel mode of human-to-human WNV transmission and additional experiments should be conducted to assess this risk further.
Malarial Infection and Curable Sexually Transmitted and Reproductive Tract Infections Among Pregnant Women in a Rural District of Zambia
Authors: Chaponda Enesia Banda , Chico R. Matthew , Bruce Jane , Michelo Charles , Vwalika Bellington , Mharakurwa Sungano , Chaponda Mike , Chipeta James , Chandramohan Daniel
Published: September 2016

Malarial infection and curable sexually transmitted and reproductive tract infections (STIs/RTIs) are important causes of adverse birth outcomes. Reducing the burden of these infections in pregnancy requires interventions that can be easily integrated into the antenatal care (ANC) package. However, efforts to integrate the control of malarial infection and curable STIs/RTIs in pregnancy have been hampered by a lack of evidence related to their coinfection. Thus, we investigated the prevalence of coinfection among pregnant women of rural Zambia. A prospective cohort study was conducted in Nchelenge District, Zambia, involving 1,086 first ANC attendees. We screened participants for peripheral malarial infection and curable STIs/RTIs (syphilis, Chlamydia, gonorrhea, trichomoniasis, and bacterial vaginosis), and collected relevant sociodemographic data at booking. Factors associated with malarial and STI/RTI coinfection were explored using univariate and multivariate regression models. Among participants with complete results (N = 1,071), 38.7% (95% confidence interval [CI] = 35.7–41.6) were coinfected with malaria parasites and at least one STI/RTI; 18.9% (95% CI = 16.5–21.2) were infected with malaria parasites only; 26.0% (95% CI = 23.5–28.8) were infected with at least one STI/RTI but no malaria parasites, and 16.4% (95% CI = 14.1–18.6) had no infection. Human immunodeficiency virus (HIV)-infected women had a higher risk of being coinfected than HIV-uninfected women (odds ratio [OR] = 3.59 [95% CI = 1.73–7.48], P < 0.001). The prevalence of malarial and STI/RTI coinfection was high in this population. An integrated approach to control malarial infection and STIs/RTIs is needed to reduce this dual burden in pregnancy.
Screening for Glucose-6-Phosphate Dehydrogenase Deficiency Using Three Detection Methods: A Cross-Sectional Survey in Southwestern Uganda
Authors: Roh Michelle E. , Oyet Caesar , Orikiriza Patrick , Wade Martina , Mwanga-Amumpaire Juliet , Boum Yap , Kiwanuka Gertrude N. , Parikh Sunil
Published: September 2016

Despite the potential benefit of primaquine in reducing Plasmodium falciparum transmission and radical cure of Plasmodium vivax and Plasmodium ovale infections, concerns over risk of hemolytic toxicity in individuals with glucose-6-phosphate dehydrogenase deficiency (G6PDd) have hampered its deployment. A cross-sectional survey was conducted in 2014 to assess the G6PDd prevalence among 631 children between 6 and 59 months of age in southwestern Uganda, an area where primaquine may be a promising control measure. G6PDd prevalence was determined using three detection methods: a quantitative G6PD enzyme activity assay (Trinity Biotech® G-6-PDH kit), a qualitative point-of-care test (CareStart™ G6PD rapid diagnostic test [RDT]), and molecular detection of the G6PD A− G202A allele. Qualitative tests were compared with the gold standard quantitative assay. G6PDd prevalence was higher by RDT (8.6%) than by quantitative assay (6.8%), using a < 60% activity threshold. The RDT performed optimally at a < 60% threshold and demonstrated high sensitivity (≥ 90%) and negative predictive values (100%) across three activity thresholds (below 60%, 30%, and 40%). G202A allele frequency was 6.4%, 7.9%, and 6.8% among females, males, and overall, respectively. Notably, over half of the G202A homo-/hemizygous children expressed ≥ 60% enzyme activity. Overall, the CareStart™ G6PD RDT appears to be a viable screening test to accurately identify individuals with enzyme activities below 60%. The low prevalence of G6PDd across all three diagnostic modalities and absence of severe deficiency in our study suggests that there is little barrier to the use of single-dose primaquine in this region.
Impacts of the Denver Cyclone on regional air quality and aerosol formation in the Colorado Front Range during FRAPPÉ 2014
Authors: Vu Kennedy T. , Dingle Justin H. , Bahreini Roya , Reddy Patrick J. , Apel Eric C. , Campos Teresa L. , DiGangi Joshua P. , Diskin Glenn S. , Fried Alan , Herndon Scott C. , Hills Alan J. , Hornbrook Rebecca S. , Huey Greg , Kaser Lisa , Montzka Denise D. , Nowak John B. , Pusede Sally E. , Richter Dirk , Roscioli Joseph R. , Sachse Glen W. , Shertz Stephen , Stell Meghan , Tanner David , Tyndall Geoffrey S. , Walega James , Weibring Peter , Weinheimer Andrew J. , Pfister Gabriele , Flocke Frank
Published: September 2016

Abstract. We present airborne measurements made during the 2014 Front Range Air Pollution and Photochemistry Experiment (FRAPPÉ) project to investigate the impacts of the Denver Cyclone on regional air quality in the greater Denver area. Data on trace gases, non-refractory submicron aerosol chemical constituents, and aerosol optical extinction (βext) at λ  =  632 nm were evaluated in the presence and absence of the surface mesoscale circulation in three distinct study regions of the Front Range: In-Flow, Northern Front Range, and the Denver metropolitan area. Pronounced increases in mass concentrations of organics, nitrate, and sulfate in the Northern Front Range and the Denver metropolitan area were observed during the cyclone episodes (27–28 July) compared to the non-cyclonic days (26 July, 2–3 August). Organic aerosols dominated the mass concentrations on all evaluated days, with a 45 % increase in organics on cyclone days across all three regions, while the increase during the cyclone episode was up to  ∼  80 % over the Denver metropolitan area. In the most aged air masses (NOx / NOy  <  0.5), background organic aerosols over the Denver metropolitan area increased by a factor of ∼  2.5 due to transport from Northern Front Range. Furthermore, enhanced partitioning of nitric acid to the aerosol phase was observed during the cyclone episodes, mainly due to increased abundance of gas phase ammonia. During the non-cyclone events, βext displayed strong correlations (r  =  0.71) with organic and nitrate in the Northern Front Range and only with organics (r  =  0.70) in the Denver metropolitan area, while correlation of βext during the cyclone was strongest (r  =  0.86) with nitrate over Denver. Mass extinction efficiency (MEE) values in the Denver metropolitan area were similar on cyclone and non-cyclone days despite the dominant influence of different aerosol species on βext. Our analysis showed that the meteorological patterns associated with the Denver Cyclone increased aerosol mass loadings in the Denver metropolitan area mainly by transporting aerosols and/or aerosol precursors from the northern regions, leading to impaired visibility and air quality deterioration.
Parameterizing cloud condensation nuclei concentrations during HOPE
Authors: Hande Luke B. , Engler Christa , Hoose Corinna , Tegen Ina
Published: September 2016

Abstract. An aerosol model was used to simulate the generation and transport of aerosols over Germany during the HD(CP)2 Observational Prototype Experiment (HOPE) field campaign of 2013. The aerosol number concentrations and size distributions were evaluated against observations, which shows satisfactory agreement in the magnitude and temporal variability of the main aerosol contributors to cloud condensation nuclei (CCN) concentrations. From the modelled aerosol number concentrations, number concentrations of CCN were calculated as a function of vertical velocity using a comprehensive aerosol activation scheme which takes into account the influence of aerosol chemical and physical properties on CCN formation. There is a large amount of spatial variability in aerosol concentrations; however the resulting CCN concentrations vary significantly less over the domain. Temporal variability is large in both aerosols and CCN. A parameterization of the CCN number concentrations is developed for use in models. The technique involves defining a number of best fit functions to capture the dependence of CCN on vertical velocity at different pressure levels. In this way, aerosol chemical and physical properties as well as thermodynamic conditions are taken into account in the new CCN parameterization. A comparison between the parameterization and the CCN estimates from the model data shows excellent agreement. This parameterization may be used in other regions and time periods with a similar aerosol load; furthermore, the technique demonstrated here may be employed in regions dominated by different aerosol species.
Sea salt emission, transport and influence on size-segregated nitrate
simulation: a case study in northwestern Europe by WRF-Chem
Authors: Chen Ying , Cheng Yafang , Ma Nan , Wolke Ralf , Nordmann Stephan , Schüttauf Stephanie , Ran Liang , Wehner Birgit , Birmili Wolfram , van der Gon Hugo A. C. Denier , Mu Qing , Barthel Stefan , Spindler Gerald , Stieger Bastian , Müller Konrad , Zheng Guang-Jie , Pöschl Ulrich , Su Hang , Wiedensohler Alfred
Published: September 2016

Abstract. Sea salt aerosol (SSA) is one of the major components of primary aerosols and has significant impact on the formation of secondary inorganic particles mass on a global scale. In this study, the fully online coupled WRF-Chem model was utilized to evaluate the SSA emission scheme and its influence on the nitrate simulation in a case study in Europe during 10–20 September 2013. Meteorological conditions near the surface, wind pattern and thermal stratification structure were well reproduced by the model. Nonetheless, the coarse-mode (PM1 − 10) particle mass concentration was substantially overestimated due to the overestimation of SSA and nitrate. Compared to filter measurements at four EMEP stations (coastal stations: Bilthoven, Kollumerwaard and Vredepeel; inland station: Melpitz), the model overestimated SSA concentrations by a factor of 8–20. We found that this overestimation was mainly caused by overestimated SSA emissions over the North Sea during 16–20 September. Over the coastal regions, SSA was injected into the continental free troposphere through an “aloft bridge” (about 500 to 1000 m above the ground), a result of the different thermodynamic properties and planetary boundary layer (PBL) structure between continental and marine regions. The injected SSA was further transported inland and mixed downward to the surface through downdraft and PBL turbulence. This process extended the influence of SSA to a larger downwind region, leading, for example, to an overestimation of SSA at Melpitz, Germany, by a factor of  ∼  20. As a result, the nitrate partitioning fraction (ratio between particulate nitrate and the summation of particulate nitrate and gas-phase nitric acid) increased by about 20 % for the coarse-mode nitrate due to the overestimation of SSA at Melpitz. However, no significant difference in the partitioning fraction for the fine-mode nitrate was found. About 140 % overestimation of the coarse-mode nitrate resulted from the influence of SSA at Melpitz. In contrast, the overestimation of SSA inhibited the nitrate particle formation in the fine mode by about 20 % because of the increased consumption of precursor by coarse-mode nitrate formation.
Geological nature of mineral licks and the reasons for
geophagy among animals
Authors: Panichev Alexander M. , Popov Vladimir K. , Chekryzhov Igor Y. , Seryodkin Ivan V , Sergievich Alexander A. , Golokhvast Kirill S.
Published: September 2016

Abstract. In this paper, the reasons for geophagy (the eating of rocks by wild herbivores) in two regions of the Eastern Sikhote-Alin volcanic belt are considered. The mineralogical and chemical features of the consumed rocks, and also the geological conditions of their formation are investigated. A comparative analysis of the mineral and chemical composition of the consumed rocks and the excrement of the animals, almost completely consisting of mineral substances, is carried out. It is established that the consumed rocks are hydrothermally-altered rhyolitic tuffs located in the volcanic calderas and early Cenozoic volcano-tectonic depressions. They consist of 30–80 % from zeolites (mainly clinoptilolites) and smectites, possessing powerful sorption properties. According to the obtained data, the main reason for geophagy may be connected with the animals’ urge to discard excessive and toxic concentrations of certain elements that are widespread in specific habitats and ingested with forage plants.
A reactivity continuum of particulate organic matter in a global ocean biogeochemical model
Authors: Aumont Olivier , van Hulten Marco , Roy-Barman Matthieu , Dutay Jean-Claude , Ethé Christian , Gehlen Marion
Published: September 2016

Abstract. The marine biological carbon pump is dominated by the vertical transfer of Particulate Organic Carbon (POC) from the surface ocean to its interior. The efficiency of this transfer plays an important role in controlling the amount of atmospheric carbon that is sequestered in the ocean. Furthermore, the abundance and composition of POC is critical for the removal of numerous trace elements by scavenging, a number of which such as iron are essential for the growth of marine organisms, including phytoplankton. Observations and laboratory experiments have shown that POC is composed of numerous organic compounds that can have very different reactivities. Yet, this variable reactivity of POC has never been extensively considered, especially in modeling studies. Here, we introduced in the global ocean biogeochemical model NEMO-PISCES a description of the variable composition of POC based on the theoretical Reactivity Continuum Model proposed by (Boudreau and Ruddick, 1991). Our model experiments show that accounting for a variable lability of POC increases POC concentrations in the ocean’s interior by one to two orders of magnitude. This increase is mainly the consequence of a better preservation of small particles that sink slowly from the surface. Comparison with observations is significantly improved both in abundance and in size distribution. Furthermore, the amount of carbon that reaches the sediments is increased by more than a factor of two, which is in better agreement with global estimates of the sediment oxygen demand. The impact on the major macro-nutrients (nitrate and phosphate) remains modest. However, iron (Fe) distribution is strongly altered, especially in the upper mesopelagic zone as a result of more intense scavenging: Vertical gradients in Fe are milder in the upper ocean which appears to be closer to observations. Thus, our study shows that the variable lability of POC can play a critical role in the marine biogeochemical cycles which advocates for more dedicated in situ and laboratory experiments.
Sedimentary ancient DNA and pollen reveal the composition of plant organic matter in Late Quaternary permafrost sediments of the Buor Khaya Peninsula (north-eastern Siberia)
Authors: Zimmermann Heike Hildegard , Raschke Elena , Epp Laura Saskia , Stoof-Leichsenring Kathleen Rosmarie , Schwamborn Georg , Schirrmeister Lutz , Overduin Pier Paul , Herzschuh Ulrike
Published: September 2016

Abstract. Organic matter deposited in ancient, ice-rich permafrost sediments is vulnerable to climate change and may contribute to the future release of greenhouse gases; it is thus important to get a better characterization of the plant organic matter within such sediments. From a Late Quaternary permafrost sediment core from the Buor Khaya Peninsula, we analysed plant-derived sedimentary ancient DNA (sedaDNA) to identify the taxonomic composition of plant organic matter, and undertook palynological analysis to assess the environmental conditions during deposition. Using sedaDNA we identified 154 taxa and from pollen and non-pollen palynomorphs we identified 86 taxa. In the deposits dated between 54 and 51 kyr BP, sedaDNA records a diverse low-centred polygon plant community including recurring aquatic pond vegetation while from the pollen record we infer terrestrial open-land vegetation with relatively dry environmental conditions at a regional scale. A fluctuating dominance of either terrestrial or swamp/aquatic taxa in both proxies allowed the local hydrological development of the polygon to be traced. In deposits dated between 11.4 and 9.7 kyr  BP (13.4–11.1 cal kyr BP), sedaDNA shows a taxonomic turnover to moist shrub tundra and a lower taxonomic richness compared to the older samples. Pollen also records a shrub tundra spectrum, mostly seen as changes in relative proportions of the most dominant taxa, while a decrease in taxonomic richness was less pronounced compared to sedaDNA. Our results show the advantages of using sedaDNA in combination with palynological analyses when macrofossils are rarely preserved. The high resolution of the sedaDNA record provides a detailed picture of the taxonomic composition of plant-derived organic matter throughout the core and palynological analyses prove valuable by allowing for inferences of regional environmental conditions.
The Radiative Forcing Model Intercomparison Project (RFMIP): experimental protocol for CMIP6
Authors: Pincus Robert , Forster Piers M. , Stevens Bjorn
Published: September 2016

Abstract. The phrasing of the first of three questions motivating CMIP6 – “How does the Earth system respond to forcing?” – suggests that forcing is always well-known, yet the radiative forcing to which this question refers has historically been uncertain in coordinated experiments even as understanding of how best to infer radiative forcing has evolved. The Radiative Forcing Model Intercomparison Project (RFMIP) endorsed by CMIP6 seeks to provide a foundation for answering the question through three related activities: (i) accurate characterization of the effective radiative forcing relative to a near-preindustrial baseline and careful diagnosis of the components of this forcing; (ii) assessment of the absolute accuracy of clear-sky radiative transfer parameterizations against reference models on the global scales relevant for climate modeling; and (iii) identification of robust model responses to tightly specified aerosol radiative forcing from 1850 to present. Complete characterization of effective radiative forcing can be accomplished with 180 years (Tier 1) of atmosphere-only simulation using a sea-surface temperature and sea ice concentration climatology derived from the host model's preindustrial control simulation. Assessment of parameterization error requires trivial amounts of computation but the development of small amounts of infrastructure: new, spectrally detailed diagnostic output requested as two snapshots at present-day and preindustrial conditions, and results from the model's radiation code applied to specified atmospheric conditions. The search for robust responses to aerosol changes relies on the CMIP6 specification of anthropogenic aerosol properties; models using this specification can contribute to RFMIP with no additional simulation, while those using a full aerosol model are requested to perform at least one and up to four 165-year coupled ocean–atmosphere simulations at Tier 1.
The role of the legislative and regulatory branches in promoting the use of geothermal energy in Latvia
Authors: Skapare I. , Kreslins A. , Cers A.
Published: September 2016

Abstract. Latvia currently is self-sufficient in energy resources up to approximately 35%. Annual fossil energy prices rise and risks of security of energy supply promote the development legislation in the matter of renewable resources. One of the Latvian Ministry of Economics' recent products is a new draft law called the "Renewable Energy Law", which has been created due to one of the European Union and Latvian national energy policy objectives: to increase the share of renewable energy up to 40% by 2020 (Moore and Vanags, 2012). Currently, geothermal energy potential is assessed at 1 × 1013kWh; nevertheless, it is difficult for geothermal energy to compete with other renewable energy resources in the Latvian energy market. A great job has been done in recent years at the legislative branch to choose the right methods for supporting the use of renewable energy resources. This paper aims is analysis of current situation and assessment of Latvian legislation possibilities to promote the use of geothermal energy.
Glacial lake change risk and management on the Chinese Nyainqentanglha in the past 40 years
Authors: Shijin Wang
Published: September 2016

Abstract. The paper analyzed synthetically spatial distribution and evolution status of moraine-dammed lakes in the Nyainqentanglha Mountain, revealed risk degree of county-based potential dangerous glacial lakes (PDGLs) outburst floods disaster by combining PDGLs outburst hazard, regional exposure, vulnerability of exposed elements and adaptation capability and using the Analytic Hierarchy Process and Weighted Comprehensive Method. The results indicate that 132 moraine-dammed lakes (> 0.02 km2) with a total area of 38.235 km2 were detected in the Nyainqentanglha in the 2010s, the lake number decreased only by 5 %, whereas total lake area expanded by 22.72 %, in which 54 lakes with a total area of 17.53 km2 are identified as PDGLs and total area increased by 144.31 %, higher significantly than 4.06 % of non-PDGLs. The zones at very high and high integrated risk of glacial lakes outburst floods (GLOFs) disaster are concentrated in the eastern Nyainqentanglha, whereas low and very low integrated risk zones are located mainly in the western Nyainqentanglha. On the county scale, Nagque and Nyingchi have the lowest hazard risk, Banbar has the highest hazard and vulnerability risk, Sog and Lhorong have the highest exposure risk. In contrast, Biru and Jiali have the highest vulnerability risk, while Gongbo'gyamda and Damxung have lowest adaptation capacity. The regionalization results for GLOF disaster risk in the study are consistent with the distribution of historical disaster sites across the Nyainqentanglha.
Slow strain waves in blocky geological media from GPS and seismological observations on the Amurian plate
Authors: Bykov Victor G. , Trofimenko Sergei V.
Published: September 2016

Abstract. Based on the statistical analysis of spatiotemporal distribution of earthquake epicenters and perennial geodetic observation series, new evidence is obtained for the existence of slow strain waves in the Earth. The results of our investigation allow us to identify the dynamics of seismicity along the northern boundary of the Amurian plate as a wave process. Migration of epicenters of weak earthquakes (2 ≤ М ≤ 4) is initiated by the east-west propagation of a strain wave front at an average velocity of 2.7 km/day. We have found a synchronous quasi-periodic variation of seismicity in equally spaced clusters with spatial periods of 3.5° and 7.26° comparable with the length of slow strain waves. The geodetic observations at GPS sites in proximity to local active faults show that in a number of cases, the GPS site coordinate seasonal variations exhibit a significant phase shift, whereas the time series of these GPS sites differ significantly from a sinusoid. Based on experimental observation data and the developed model of crustal block movement we have shown that there is one possible interpretation for this fact that the trajectory of GPS station position disturbance is induced by migrating of crustal deformation in the form of slow waves.
Eruptive shearing of tube pumice: pure and simple
Authors: Dingwell Donald B. , Lavallée Yan , Hess Kai-Uwe , Flaws Asher , Marti Joan , Nichols Alexander R. L. , Gilg H. Albert , Schillinger Burkhard
Published: September 2016

Abstract. Understanding the physicochemical conditions extant and mechanisms operative during explosive volcanism is essential for reliable forecasting and mitigation of volcanic events. Rhyolitic pumices reflect highly vesiculated magma whose bubbles can serve as a strain indicator for inferring the state of stress operative immediately prior to eruptive fragmentation. Obtaining the full kinematic picture reflected in bubble population geometry has been extremely difficult, involving dissection of a small number of delicate samples. The advent of reliable high-resolution tomography has changed this situation radically. Here we demonstrate via the use of tomography how a statistically powerful picture of the shapes and connectivity of thousands of individual bubbles within a single sample of tube pumice emerges. The strain record of tube pumice is modelled using empirical models of bubble geometry and liquid rheology, reliant on a constraint of magmatic water concentration. FTIR analysis reveals an imbalance in water speciation, suggesting post-eruption hydration, further supported by hydrogen and oxygen isotope measurements. Our work demonstrates that the strain recorded in the tube pumice dominated by simple shear (not pure shear) in the late deformational history of vesicular magma before eruption. This constraint in turn implies that magma ascent is conditioned by a velocity gradient (across the conduit) at the point of origin of tube pumice. Magma ascent accompanied by simple shear should enhance high eruption rates inferred independently for these highly viscous systems.