bluuebunny/crossref_metadata_2025 huggingface dataset:
Recombination of CdHgTe Quantum Dot and “Dextran - Magnetic Layered Double Hydroxide - Fluorouracil” System for Cell Imaging
Authors: Pei Qin Yu , Wang Rui , Jin Xue Qin , Gou Guo Jing
Published: February 2018

In this paper, we synthesized a CdHgTe type water-soluble quantum dots, combined in the next time with the drug delivery system "dextran - magnetic layered double hydroxide - fluorouracil" (DMF), built a new nanostructures platform QD@DMF for blending the fluorescent probe function of quantum dot together with the magnetic targeting curative effect of the DMF system. The Fluorescence spectrophotometer, Ultraviolet spectrophotometer, TEM and XRD were used to characterize the luminescent properties, particle morphology and phase characteristics of the QD@DMF samples. The experiments on cell imaging were carried out by laser con-focal scan microscopy technique. Results showed that the CdHgTe QDs could be successfully grafted onto the surface of the DMF system through electrostatic coupling, forming a special structure based on magnetic layered double hydroxide with a near-infrared emission wavelength in 575~780 nm. Compared with QDs, the QD@DMF composite could significantly improve the cell imaging effect, the label intensity increased with the magnetic field intensity and obeyed the linear relationship Dmean = 1.760+0.013B. The fluorescent magnetic nanoparticles maintained not only the super-paramagnetic of DMF but also the photoluminescence properties of the QDs, implicating that the QD@DMF composite may be an effective multifunction tool for optical bio-imaging and magnetic targeted therapy.
Spin Injection into Graphene from Heusler Alloy Co2MnGe (111) Surface: A First Principles Study
Authors: Wang Ya Xin , Xia Tong Sheng
Published: February 2018

To obtain a larger spin signal for use in graphene-based spintronic devices, the spin injection efficiency needs to be enhanced. Previously researchers can increase the efficiency by inserting a tunnel barrier such as Al2O3or MgO between ferromagnet and graphene. However, the key value in spin transport is still very low because of the conductance mismatch as well as the limit to fabricate a high-quality tunnel barrier at the junction surface. Here we use a highly spin-polarized ferromagnetic material—Heusler alloy Co2MnGe as a substitutional scheme without the tunnel barrier. The spin injection efficiency of our Co2MnGe (111)/graphene junction can be as high as 73% which is much higher than 1% of ferromagnet/graphene or 30% of ferromagnet/oxide/graphene using first-principles study. The large spin polarization can be explicated by analyzing the transmission spectrum at the nonequilibrium state.
Mechanism of Mn(II) Absorption and Desorption with CFBC Fly Ash Modified by Alkaline Wet Ball Milling
Authors: Xu Ya Hong , Xu Zhong Hui , Jiang Zao , Li Na , Li Ping , Zheng Lei
Published: February 2018

In this study, the adsorption properties of modified circulating fluidized-bed combustion (CFBC) fly ash by alkali wet millingwere investigated for Mn (II) cations. The effects ofNaOH content,milling speed and milling timeon the modification processof CFBC fly ashwerestudied. Preliminary statistical analysis has indicated thatmetal concentration, time, pH, fly ash dosage and temperaturewere the most importantvariables that affect the adsorption capacity. Results lead towards the conclusion that alkali wet millingtreatment cansignificantly increasethe adsorption capacity of the CFBC fly ash. The adsorption mechanism of the modified CFBCfly ash was determined using Langmuir, Freundlich isotherms and the Lagergren pseudo-first-order, pseudo-second-order, Elovich equation and the intraparticle diffusion equation, which indicated it was not thesole rate determiningstep, and the adsorption process was controlled by physical and chemical adsorption.The results showed that theCFBC fly ash can be utilized as a low-cost adsorbent for the removal of Mn (II) ionsfrom solution.
Combined Computational and Experimental Study of the Pressure Dependence of the Structural and Vibrational Properties on Solid Naphthalene C10H8
Authors: Xiao Ling Ping , Zeng Li , Yang Xue
Published: February 2018

We present high-quality optical data and density functional theory calculations for the structural and vibrational properties of solid naphthalene (C10H8) under pressure up to 21.5 GPa. Our results demonstrate that almost all the modes shift toward higher frequencies and some peaks are broadened with increasing pressure. Comparing the pressure effect on the shortest intermolecular distances and on the bond lengths we confirm the expected result that the intramolecular interaction are less sensitive to pressure than the intermolecular interactions. These findings are shown to be in agreement with experimental results and hint towards the evolution of intermolecular interaction with pressure. Moreover, within our data the lattice modes exhibit more drastic changes than intramolecular modes, which are due to there being greater intermolecular distortions than intramolecular under applied pressure. In combination with theoretical and experimental studies, these results permit detailed characterization of the structural and vibrational changes of naphthalene as a function of pressure.
The Developing Status of High-Throughput Drug Screening Microfluidic Chip by FRET on Medicine
Authors: Zhang Xin Yu , Huang Qiu Hong , Yang Mei , Liao Xiao Ling , Shao Ze Yu , Huang Jin Xia , Xu Wen Feng , Hu Xiao
Published: February 2018

High-throughput drug screening microfluidic chip has good biocompatibility and faveriable functional integration, which is the excellent platform for high-throughput screening. Importantly, FRET (Fluorescence Resonance Energy Transfer) technology is the most efficient detection means at present. In this paper, we introduce the development of drug screening microfluidic chip on cellular level and the application of FRET technology on cell detection. Further, we discusse the possibility of FRET applied in the field of microfluidic biochip.
Characterization of Porous Hyaluronan/β-TCP Scaffolds Prepared through Heterogeneous Crosslinking
Authors: Zhao Rui Min , Xue Xian Ya , Wang You Fa
Published: February 2018

Porous Hyaluronan/β-tricalcium phosphate composite scaffolds were synthesized through lyophilizing and subsequent heterogeneous crosslinking method. The morphology of the composite scaffolds were investigated by scanning electron microscopy (SEM). The swelling behavior, mechanical property, degradation behavior and cell adhesion ability of samples were also studied. The results revealed that hyaluronan mainly contributed to the polymer matrix and water adsorption, whereas β-TCP acted as a reinforcement to strengthen the porous structure, while too much β-TCP would make the structure collapse. The pose size of obtained scaffolds ranges from100μm to 200μm and the porosity decreased with the increase of β-TCP content. The degradation behavior and cell adhesion test indicated that increasing hyaluronan concentration can effectively improve the degradability of scaffolds and the incorporation of β-TCP improved the cell adhesion performance. Thus a simple way to prepare hyaluronan-based composite scaffolds was provided, which could be potentially used as an tissue engineering material.
Synthesis and Electrochemical Performance of Silicon/Carbon Composite Anodes through Ball Milling and Spray Drying Pyrolysis Process
Authors: Wang Ying , Wu Hao , Xiao Fang Ming , Tang Ren Heng , Sun Tai
Published: February 2018

A facile method was developed to synthesize amorphous carbon coated nano-sized silicon and graphite by using glucose or pitch as organic carbon source, nano-sized silicon particles were uniformly coated onto the artificial graphite by combined ball milling and spray drying pyrolysis, and the effect of binder types, binder amounts on the precursor morphology, feed rate and spray pressure on the electrochemical performance were investigated in detail. The partial size, surface morphology and electrochemical performances of the as-synthesized powders were analyzed by particulate size description analyzer (PSDA), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and constant current charge/discharge tools. It is found that, citric acid and binder are important for improving the free-aggregation of nano-sized silicon and the morphologyof combined silicon and graphite. Therefore, under the optimal experimental conditions, amorphous carbon from pitch coated nano-sized silicon and graphite composite anodes exhibits much higher electrochemical performance. It can deliver the first discharge specific capacity of 796.3mA·h/g at a current density of 100 mA/g, as well as 85% of initial coulombic efficiency. Additionally, the discharge specific capacity retains 724.9mA·h/g, and the discharge capacity retention of a half cell system is 91% after 50 cycles.
Point prevalence & risk factor assessment for hospital-acquired infections in a tertiary care hospital in Pune, India
Authors: Nair Velu , Sahni A.K. , Sharma Dinesh , Grover Naveen , Shankar S. , Chakravarty A. , Patrikar Seema , Methe Kailas , Jaiswal S.S. , Dalal S.S. , Kapur Anupam , Verma Rajesh , Prakash Jyoti , Gupta Ashutosh , Bhansali Anvita , Batura Deepak , Rao G. Gopal , Joshi D.P. , Chopra B.K.
Published: February 2018

Background & objectives:

Hospital-acquired infections (HAIs) are a major challenge to patient safety and have serious public health implications by changing the quality of life of patients and sometimes causing disability or even death. The true burden of HAI remains unknown, particularly in developing countries. The objective of this study was to estimate point prevalence of HAI and study the associated risk factors in a tertiary care hospital in Pune, India.

Methods:

A series of four cross-sectional point prevalence surveys were carried out between March and August 2014. Data of each patient admitted were collected using a structured data entry form. Centers for Disease Control and Prevention guidelines were used to identify and diagnose patients with HAI.

Results:

Overall prevalence of HAI was 3.76 per cent. Surgical Intensive Care Unit (ICU) (25%), medical ICU (20%), burns ward (20%) and paediatric ward (12.17%) were identified to have significant association with HAI. Prolonged hospital stay [odds ratio (OR=2.81), mechanical ventilation (OR=18.57), use of urinary catheter (OR=7.89) and exposure to central air-conditioning (OR=8.59) had higher odds of acquiring HAI (P<0.05).

Interpretation & conclusions:

HAI prevalence showed a progressive reduction over successive rounds of survey. Conscious effort needs to be taken by all concerned to reduce the duration of hospital stay. Use of medical devices should be minimized and used judiciously. Healthcare infection control should be a priority of every healthcare provider. Such surveys should be done in different healthcare settings to plan a response to reducing HAI.
Combination of interleukin-10 gene promoter polymorphisms with HLA-DRB1*15 allele is associated with multiple sclerosis
Authors: Shahbazi Majid , Abadi Javad Sadeghi Allah , Roshandel Danial , Koochaki Maryam , Amiri Hosein , Kohansal Rahim , Baghbanian Seied Mohammad , Zamani Mahdi
Published: February 2018

Background & objectives:

Multiple sclerosis (MS) is common in some ethnic groups. Interleukin-10 (IL-10) is a potent anti-inflammatory and immunosuppressive cytokine that may be an important regulator in MS disease pathogenesis. IL-10 promoter includes several single nucleotide polymorphisms and the level of IL-10 expression is related to these polymorphisms. Furthermore, loci within the histocompatibility regions are responsible for susceptibility to MS. The aim of this study was to investigate the association of IL-10 gene promoter polymorphisms and HLA-DRB1*15 allele frequencies with MS susceptibility in an Iranian population.

Methods:

In this study 336 MS patients and 454 healthy controls were included. Genomic DNA was purified from peripheral blood samples by a standard protocol. Genotyping was performed by the sequence-specific primer polymerase chain reaction method.

Results:

IL-10 −1082 G/G and IL-10 −819 C/C genotypes were more frequent in MS patients than healthy individuals. DRB1* 15 allele showed a higher frequency among MS patients compared to controls.

Interpretation & conclusions:

The IL-10 and HLA-DRB1*15 polymorphisms were associated with the susceptibility to MS in Iranian patients. Our results suggest that gene-gene interaction of IL-10 polymorphisms and HLA-DRB1*15 alleles may be important factors in the development of MS.
Association of rheumatic fever & rheumatic heart disease with plausible early & late-stage disease markers
Authors: Sarkar Subendu , Rastogi Mukul , Chaudhary Priyanka , Kumar Rajesh , Arora Priya , Sagar Vivek , Sahni Inderpal Singh , Shethi Sunil , Thakur Khemraj , Ailawadhi Sourav , Toor Devinder , Chakraborti Anuradha
Published: February 2018

Background & objectives:

Rheumatic fever (RF) and rheumatic heart disease (RHD) are the autoimmune sequelae caused by Group A Streptococcus. RHD still remains a major concern in the developing countries due to its poor diagnosis, lack of vaccines and social awareness among population. This study was aimed to identify the plausible early- and late-stage disease markers associated with RF/RHD.

Methods:

A total of 84 patients with confirmed pharyngitis (n=18), RF (n=23) and RHD (n=43) were included in the comparative analysis of different factors involved in host-pathogen interaction during RF/RHD pathogenesis.

Results:

This study revealed high titre of serum antistreptolysin O (ASO) antibody in pharyngitis compared to RF and RHD patients, whereas procollagen type 1 C-peptide (PICP) level was elevated in RHD which showed an inverse correlation with serum ASO titre. The significant elevation of serum anti-peptide associated with RF (PARF) antibody in RF patients was correlated as a probable stage-specific determinant. In addition, pro-inflammatory cytokine profile revealed high levels of interleukin-12 (IL-12)/IL-23p40, IL-17A in RF, whereas IL-6 concentration was higher in RHD compared to healthy controls.

Interpretation & conclusions:

The overall assessment of the factors/disease markers involved in host-pathogen interaction in RF/RHD may be suggestive of plausible disease marker in different groups of patients. Further studies with larger sample need to be done to better understand RF/RHD pathogenesis.
Sudden unexpected death in epilepsy
Authors: Duble Shishir Nagesh , Thomas Sanjeev V.
Published: February 2018

People with epilepsy have increased risk of premature death, and their life expectancy may reduce by 2-10 yr. Population- and hospital-based studies have shown that the excess mortality in epilepsy is not entirely explained by deaths directly attributable to epilepsy such as accidents and drowning during a seizure. It is also significantly contributed by deaths from other causes such as cardiac deaths, deaths due to malignancies and other causes. It had recently been recognized that sudden unexpected deaths in epilepsy (SUDEP) contributed to a small yet important proportion of mortality in epilepsy. SUDEPs are deaths (witnessed or unwitnessed) unrelated to trauma, drowning or status epilepticus and not attributable to any specific medical conditions. Several factors related to epilepsy and drug therapy have been found to be associated with higher risk of SUDEP.
Creatividad y eficacia en la Comunidad Valenciana: la figura del planner en el proceso creativo
Authors: Fanjul Peyró Carlos , González Oñate Cristina , Arranz Peña Marta
Published: February 2018

El presente trabajo analiza la situación del planificador estratégico en la Comunidad Valenciana. Este perfil nació como una figura imprescindible para aplicar la investigación sobre los públicos a la realización de campañas publicitarias, consiguiendo una comunicación más eficaz. Centrándonos en la relación entre el departamento de planificación estratégica con el de creatividad, buscamos conocer si es necesaria la introducción del planner en el proceso creativo, así como las funciones que deberá desarrollar para conseguir campañas creativas a la par de eficaces. Metodología: Por ello, realizamos una revisión bibliográfica para analizar las funciones básicas de este perfil, así como su relación con la creatividad. En segundo lugar, desarrollamos un trabajo de campo, donde, a través de un cuestionario a profesionales de la región y varias entrevistas a planificadores estratégicos de referencia, buscamos entender la situación del planner en la Comunidad Valenciana y el camino a seguir para la evolución de dicho perfil. Resultados y conclusiones: En este análisis observamos como el planner en la región valenciana se encuentra todavía en una etapa primigenia, por lo que aún queda camino por recorrer para hacer del planning una disciplina real. A su vez, hemos podido constatar la necesidad de incluir al planner en el proceso creativo, ya que tanto planificadores como creativos se muestran interesados en esta colaboración. Finalmente, proponemos una descripción de cuáles deben ser las tareas del planificador estratégico en este proceso para ayudar al departamento creativo.
Analysis of library patrons’ usage of social media in a Nigerian university library
Authors: Fabunmi Samuel O.
Published: February 2018

The changing nature of library services and the advent of social media network technology have created emphasis on its usage in academic institutions. Librarians are using the latest social media technology in marketing their information products and services to the library patrons. The aim of this study is investigating the library patrons’ usage of social media in a Nigerian University Library; and the instrument for data collection was a questionnaire of Two hundred and thirty-eight copies and the usable rate of returned responses was 87% of the anticipated responses. The findings revealed that Whatsapp and facebook were greatly used as it creates current awareness on the happening in the institution; it also established that social media enabled students to access local and web contents of information needs globally. The findings revealed that critical social media literacy is needed to help students to critically deal with the large amounts of information they interact with by sharing its content on social media. Furthermore, the research provides information on how this technology can be fully exploited for the benefits of the students and community at large.Keywords: academic library, library patrons, social media, use
Optimization of machining parameters of hard porcelain on a CNC machine by Taguchi-and RSM method
Authors: Agrawal Saurabh , Gaur Manoj kumar , Kasdekar Dinesh kumar , Agrawal Sharad
Published: February 2018

In order to build up a relationship between quality and productivity, the present work focuses an optimized approach to  establishing the multi-objective machining  parameters and mathematical models for Pressure and Voltage on CNC turning  machine (SINUMERIK802D). The Pressure and Voltage seem to be known as  quality issues; they are as well presumed to have direct association with productivity. In this study, minimization of response parameters has been identified by using design of  experimental methods, Taguchi Analysis and Response surface methodology (RSM). The conduct of experiments was made by employing the Taguchi’s L27 Orthogonal array to design the experiment by considering spindle speed (SS), feed rate (FR), angle of cut (AOC) and depth of cut (DOC) as Machining parameters. The model for the Pressure and Voltage, as the function of  response parameters, is obtained using the RSM. Finally, the result of developed mathematical model is examined by ANOVA. Experimental results indicate that the feed rate, angle of cut and depth of cut are the leading parameters that affect the Pressure (P). similarly for Voltage (V), all the cutting parameters (Spindle speed, feed rate, angle of cut and depth of cut) are found to be significant, which can be diminished when the significant factors were kept at the lower level, while other factors were kept at the highest level. On the Basis of analysis, it is found that both the optimization techniques predict the results in fair agreement.Keywords:SINUMERIK802D, Machining parameters, RSM, Taguchi Method, ANOVA.
Opvoednetwerken van migranten
Authors: de Haan Mariëtte
Published: February 2018

English title: Support networks of immigrant parents: A blueprint for the educative community in the 21st century?

How can educative communities -initiatives of citizens to organize collective support for child raising- be optimized given the changing social fabric of the 21st century? Using the idea of networked individualism as a prototype of how support is organized in our current era, the question is raised how collective arrangements for child raising can be conceived when autonomy and individualism in parenting still gain importance. An empirical study of support networks of immigrant parents is used to point to the variety of ways in which individual parents seek to build new networks post-migration. Turning their back to old collectivities, these parents build individual networks of peers and professionals to gain new and specialized expertise according to their specific needs. It is argued that their network strategies can be a source of inspiration for how to conceive of educative communities in the 21st century given their ability to seek out new connections and expertise, their awareness of the importance of peer learning, and ability to connect the sometimes contradictory knowledge in order to make it work for their parenting.
Het evidence-beest en de normativiteit van opvoeding
Authors: Hopman Marit
Published: February 2018

The Evidence ‘Beast’ and the Normativity of Child-Rearing

In 2008 Micha de Winter warned people to watch out for, what he coined, ‘the Evidence Beast’, referring to a too narrow focus within the Dutch youth care system on evidence and effectivity. This concern was also the main instigator for my PhD research conducted under his (and Prof. Koops’) supervision. In this article I address some of the ‘beasts’ of a strict evidence-based focus within the professional field of youth care. Some of these problems are related to the ways in which EBP is used in the Dutch youth care system (a strict focus on effectivity, a lack of professional reflection and a lack of professionals’ discretionary power). The most important and most Dewinterian issue however is the implicit normativity in child rearing in contrast to the rather technical, and presumed neutral, child rearing approach in youth care interventions. I conclude the article with several suggestions for the future, in order to give more room to important value-laden elements in the support that is offered to parents through youth care interventions.
Op zoek naar verbinding in de samenleving
Authors: Horjus Bob , van Dijken Maartje
Published: February 2018

Looking for connection in society; Lessons from eight years of research on The Peaceable Neighbourhood.

Research among the Dutch population indicates an undesirable trend of increasing segregation. Scientific literature shows that a solution lies in the strengthening of relationships between (groups) of citizens. Therefore, in this essay, we explore how The Peaceable Neighbourhood contributed to strengthening relationships between children, parents, other residents and professionals. We describe cases and practical experience based on research on the Peaceable Neighbourhood program. Findings show that the Children’s Council can act as a bridge between children and other groups of residents in their neighbourhood. There are also indications that relations among professionals working with children were mutually reinforced. However, strengthening relationships between parents and professionals (linking social capital) and between groups of parents (bridging social capital) seems less successful. Parents were often unable to take initiatives or deal with the, in their eyes, more powerful and competent professionals. Professionals had difficulties in giving up responsibility. As a result of the Peaceable Neighbourhood activities, networks of parents with the same migrant background became stronger (bonding social capital), but the strengthening of relationships with members of other populations remained behind. Practical experiences teaches us that with adequate and personal commitment of professionals, trust can be gained from (groups of) parents, who can, subsequently, connect with other (groups of) parents with more confidence.
Opvoeden: Een privé- én publieke zaak
Authors: Kesselring Marije
Published: February 2018

Childrearing: a private and public issue

In the run-up to the transformation of youth and family care, the ‘educative civil society’ (ECS) – the joint efforts of citizens in the upbringing of children and adolescents – has increasingly received attention. Many municipalities have embraced the ECS and translated into policy plans and practice initiatives. At the same time, there is criticisms: is it feasible to expect that all parents are willing to form childrearing networks? This article reports on a focus group study on parents’ willingness to involve others in the upbringing of their children. The results suggest that sharing childrearing responsibilities is a delicate issue that comes with conditions. At the same time, the results give rise to a nuancing of the antithesis ‘private worry vs. public issue’: parents believe that they do not have, nor insist on having, the monopoly on childrearing and emphasize the additional and compensatory value of secondary caregivers, both for their children and for themselves as primary caregivers. These nuances give nourishment to the debate on the feasibility and future development of the ECS.
Het spanningsveld tussen ‘front-’ en ‘backstage’ in intensieve pedagogische thuisbegeleiding
Authors: Steens Roos , Hermans Koen , Van Regenmortel Tine
Published: February 2018

The tension between ‘front-’ and ‘backstage’ in intensive pedagogical home-based family support. A multiple case study

Both in Flanders and in the Netherlands, there is a growing attention to family preservation programs. Research on family preservation is, however, mainly conducted within a positivist framework. Because of that, we have gathered some insights into overall trends, but we have very little detailed information about the day-to-day practice of family preservation. What happens when a social worker and a family are face-to-face? What are the underlying mechanisms that influence the impact of a family preservation program? In this study, we use a multiple case-study with a triangulation of different ethnographical methods to build knowledge about the complex and dynamic tension in which family preservation programs take shape. We illustrate the discrepancy between how an intervention is displayed ‘front stage’ (in case-files, reports, registrations) and what happens ‘back stage’ (during the face-to-face contacts). We describe how, at the beginning and at the end of a treatment process, the focus on the ‘front stage’ influences the attunement between a social worker and a family. In between, however, the social worker undertakes small but significant actions at the ‘back stage’ of the intervention process, which are regarded as extremely helpful by the families. By shedding light on what happens beyond case-files, reports and registrations, it becomes possible to open the black box of social interventions and enrich the conceptual framework of ‘what works’ in family preservation. In addition, by working collaboratively between researchers, social workers and families, a collaborative research community is formed and local improvement processes are enhanced.
Characteristics and source apportionment of fine haze aerosol in Beijing during the winter of 2013
Authors: Shang Xiaona , Zhang Kai , Meng Fan , Wang Shihao , Lee Meehye , Suh Inseon , Kim Daigon , Jeon Kwonho , Park Hyunju , Wang Xuezhong , Zhao Yuxi
Published: February 2018

Abstract. For PM2.5 filter samples collected daily at the Chinese Research Academy of Environmental Sciences (Beijing, China) from December of 2013 to February of 2014 (the winter period), chemical characteristics and sources were investigated with an emphasis on haze events in different alert levels. During the 3 months, the average PM2.5 concentration was 89 µg m−3, exceeding the Chinese national standard of 75 µg m−3 in 24  h. The maximum PM2.5 concentration was 307 µg m−3, which characterizes developed-type pollution (PM2.5 / PM10>0.5) in the World Health Organization criteria. PM2.5 was dominated by SO42−, NO3−, and pseudo-carbonaceous compounds with obvious differences in concentrations and proportions between non-haze and haze episodes. The non-negative matrix factorization (NMF) analysis provided reasonable PM2.5 source profiles, by which five sources were identified: soil dust, traffic emission, biomass combustion, industrial emission, and coal combustion accounting for 13, 22, 12, 28, and 25  % of the total, respectively. The dust impact increased with northwesterlies during non-haze periods and decreased under stagnant conditions during haze periods. A blue alert of heavy air pollution was characterized by the greatest contribution from industrial emissions (61  %). During the Chinese Lantern Festival, an orange alert was issued and biomass combustion was found to be the major source owing to firework explosions. Red-alert haze was almost equally contributed by local traffic and transported coal combustion emissions from the vicinity of Beijing (approximately 40  % each) that was distinguished by the highest levels of NO3− and SO42−, respectively. This study also reveals that the severity and source of haze are largely dependent on meteorological conditions.
Chemical characterization of fine particulate matter emitted by peat fires in Central Kalimantan, Indonesia, during the 2015 El Niño
Authors: Jayarathne Thilina , Stockwell Chelsea E. , Gilbert Ashley A. , Daugherty Kaitlyn , Cochrane Mark A. , Ryan Kevin C. , Putra Erianto I. , Saharjo Bambang H. , Nurhayati Ati D. , Albar Israr , Yokelson Robert J. , Stone Elizabeth A.
Published: February 2018

Abstract. Fine particulate matter (PM2.5) was collected in situ from peat smoke during the 2015 El Niño peat fire episode in Central Kalimantan, Indonesia. Twenty-one PM samples were collected from 18 peat fire plumes that were primarily smoldering with modified combustion efficiency (MCE) values of 0.725–0.833. PM emissions were determined and chemically characterized for elemental carbon (EC), organic carbon (OC), water-soluble OC, water-soluble ions, metals, and organic species. Fuel-based PM2.5 mass emission factors (EFs) ranged from 6.0 to 29.6 g kg−1 with an average of 17.3 ± 6.0 g kg−1. EC was detected only in 15 plumes and comprised  ∼ 1 % of PM mass. Together, OC (72 %), EC (1 %), water-soluble ions (1 %), and metal oxides (0.1 %) comprised 74 ± 11 % of gravimetrically measured PM mass. Assuming that the remaining mass is due to elements that form organic matter (OM; i.e., elements O, H, N) an OM-to-OC conversion factor of 1.26 was estimated by linear regression. Overall, chemical speciation revealed the following characteristics of peat-burning emissions: high OC mass fractions (72 %), primarily water-insoluble OC (84 ± 11 %C), low EC mass fractions (1 %), vanillic to syringic acid ratios of 1.9, and relatively high n-alkane contributions to OC (6.2 %C) with a carbon preference index of 1.2–1.6. Comparison to laboratory studies of peat combustion revealed similarities in the relative composition of PM but greater differences in the absolute EF values. The EFs developed herein, combined with estimates of the mass of peat burned, are used to estimate that 3.2–11 Tg of PM2.5 was emitted to atmosphere during the 2015 El Niño peatland fire event in Indonesia. Combined with gas-phase measurements of CO2, CO, CH4, and volatile organic carbon from Stockwell et al. (2016), it is determined that OC and EC accounted for 2.1 and 0.04 % of total carbon emissions, respectively. These in situ EFs can be used to improve the accuracy of the representation of Indonesian peat burning in emission inventories and receptor-based models.
A very limited role of tropospheric chlorine as a sink of the greenhouse gas methane
Authors: Gromov Sergey , Brenninkmeijer Carl A. M. , Jöckel Patrick
Published: February 2018

Abstract. Unexpectedly large seasonal phase differences between CH4 concentration and its 13C/12C isotopic ratio and their inter-annual variations observed in southern hemispheric time series have been attributed to the Cl+CH4 reaction, in which 13CH4 is discriminated strongly compared to OH+CH4, and have provided the only and indirect evidence of a hemispheric-scale presence of oxidative cycle-relevant quantities of tropospheric atomic Cl. Our analysis of concurrent New Zealand and Antarctic time series of CH4 and CO mixing and isotope ratios shows that a corresponding 13C/12C variability is absent in CO. Using the AC-GCM EMAC model and isotopic mass balancing for comparing the periods of presumably high and low Cl, it is shown that variations in extra-tropical Southern Hemisphere Cl can not have exceeded 0.9 × 103 atoms cm−3. It is demonstrated that the 13C/12C ratio of CO is a sensitive indicator for the isotopic composition of reacted CH4 and therefore for its sources. Despite ambiguities about the yield of CO from CH4 oxidation, with this yield being an important factor in the budget of CO, and uncertainties about the isotopic composition of sources of CO, in particular biomass burning, the contribution of Cl to the removal of CH4 in the troposphere is probably much lower than currently assumed.
Reliability ensemble averaging of 21st century projections of terrestrial net primary productivity reduces global and regional uncertainties
Authors: Exbrayat Jean-François , Bloom A. Anthony , Falloon Pete , Ito Akihiko , Smallman T. Luke , Williams Mathew
Published: February 2018

Abstract. Multi-model averaging techniques provide opportunities to
extract
additional information from large ensembles of simulations. In
particular, present-day model skill can be used to evaluate their
potential performance in future climate simulations. Multi-model
averaging methods have been used extensively in climate and
hydrological sciences, but they have not been used to constrain
projected plant productivity responses to climate change, which is
a major uncertainty in Earth system modelling. Here, we use three
global observationally orientated estimates of current net primary
productivity (NPP) to perform a reliability ensemble averaging (REA) method
using 30 global simulations of the 21st century change in NPP based
on the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP)
”business as usual” emissions scenario. We find that the three
REA methods support an increase in global NPP by the end of the 21st
century (2095–2099) compared to 2001–2005, which is 2–3 %
stronger than the ensemble ISIMIP mean value of
24.2 Pg C y−1. Using REA also leads to a 45–68 %
reduction in the global uncertainty of 21st century NPP projection,
which strengthens confidence in the resilience of the
CO2 fertilization effect to climate change. This reduction
in uncertainty is especially clear for boreal ecosystems although it
may be an artefact due to the lack of representation of nutrient
limitations on NPP in most models. Conversely, the large uncertainty
that remains on the sign of the response of NPP in semi-arid regions
points to the need for better observations and model development in
these regions.
Derived Optimal Linear Combination Evapotranspiration (DOLCE): a global gridded synthesis ET estimate
Authors: Hobeichi Sanaa , Abramowitz Gab , Evans Jason , Ukkola Anna
Published: February 2018

Abstract. Accurate global gridded estimates of evapotranspiration (ET) are key
to understanding water and energy budgets, in addition to being required
for model evaluation. Several gridded ET products have already been
developed which differ in their data requirements, the approaches
used to derive them and their estimates, yet it is not clear which
provides the most reliable estimates. This paper presents a new
global ET dataset and associated uncertainty with monthly temporal
resolution for 2000–2009. Six existing gridded ET products are
combined using a weighting approach trained by observational
datasets from 159 FLUXNET sites. The weighting method is based on
a technique that provides an analytically optimal linear combination
of ET products compared to site data and accounts for both the
performance differences and error covariance between the
participating ET products. We examine the performance of the
weighting approach in several in-sample and out-of-sample tests that
confirm that point-based estimates of flux towers provide
information on the grid scale of these products. We also provide
evidence that the weighted product performs better than its six
constituent ET product members in four common metrics. Uncertainty
in the ET estimate is derived by rescaling the spread of
participating ET products so that their spread reflects the ability
of the weighted mean estimate to match flux tower data. While issues
in observational data and any common biases in participating ET
datasets are limitations to the success of this approach, future
datasets can easily be incorporated and enhance the derived product.
Debris flow run-out simulation and analysis using a dynamic model
Authors: Melo Raquel , van Asch Theo , Zêzere José L.
Published: February 2018

Abstract. Only two months after a huge forest fire occurred in the upper part of a
valley located in central Portugal, several debris flows were triggered by
intense rainfall. The event caused infrastructural and economic damage,
although no lives were lost. The present research aims to simulate the run-out
of two debris flows that occurred during the event as well as to calculate
via back-analysis the rheological parameters and the excess rain involved. Thus,
a dynamic model was used, which integrates surface runoff, concentrated
erosion along the channels, propagation and deposition of flow material.
Afterwards, the model was validated using 32 debris flows triggered during
the same event that were not considered for calibration. The rheological and
entrainment parameters obtained for the most accurate simulation were then
used to perform three scenarios of debris flow run-out on the basin scale.
The results were confronted with the existing buildings exposed in the
study area and the worst-case scenario showed a potential inundation that may
affect 345 buildings. In addition, six streams where debris flow occurred in
the past and caused material damage and loss of lives were identified.
The seismo-hydromechanical behavior during deep geothermal reservoir stimulations: open questions tackled in a decameter-scale in situ stimulation experiment
Authors: Amann Florian , Gischig Valentin , Evans Keith , Doetsch Joseph , Jalali Reza , Valley Benoît , Krietsch Hannes , Dutler Nathan , Villiger Linus , Brixel Bernard , Klepikova Maria , Kittilä Anniina , Madonna Claudio , Wiemer Stefan , Saar Martin O. , Loew Simon , Driesner Thomas , Maurer Hansruedi , Giardini Domenico
Published: February 2018

Abstract. In this contribution, we present a review of scientific research results that address seismo-hydromechanically coupled processes relevant for the development of a sustainable heat exchanger in low-permeability crystalline rock and introduce the design of the In situ Stimulation and Circulation (ISC) experiment at the Grimsel Test Site dedicated to studying such processes under controlled conditions. The review shows that research on reservoir stimulation for deep geothermal energy exploitation has been largely based on laboratory observations, large-scale projects and numerical models. Observations of full-scale reservoir stimulations have yielded important results. However, the limited access to the reservoir and limitations in the control on the experimental conditions during deep reservoir stimulations is insufficient to resolve the details of the hydromechanical processes that would enhance process understanding in a way that aids future stimulation design. Small-scale laboratory experiments provide fundamental insights into various processes relevant for enhanced geothermal energy, but suffer from (1) difficulties and uncertainties in upscaling the results to the field scale and (2) relatively homogeneous material and stress conditions that lead to an oversimplistic fracture flow and/or hydraulic fracture propagation behavior that is not representative of a heterogeneous reservoir. Thus, there is a need for intermediate-scale hydraulic stimulation experiments with high experimental control that bridge the various scales and for which access to the target rock mass with a comprehensive monitoring system is possible. The ISC experiment is designed to address open research questions in a naturally fractured and faulted crystalline rock mass at the Grimsel Test Site (Switzerland). Two hydraulic injection phases were executed to enhance the permeability of the rock mass. During the injection phases the rock mass deformation across fractures and within intact rock, the pore pressure distribution and propagation, and the microseismic response were monitored at a high spatial and temporal resolution.
Climate warming over the past half century has led to thermal degradation of permafrost on the Qinghai–Tibet Plateau
Authors: Ran Youhua , Li Xin , Cheng Guodong
Published: February 2018

Abstract. Air temperature increases thermally degrade permafrost, which has widespread
impacts on engineering design, resource development, and environmental
protection in cold regions. This study evaluates the potential thermal
degradation of permafrost over the Qinghai–Tibet Plateau (QTP) from the 1960s
to the 2000s using estimated decadal mean annual air temperatures (MAATs) by
integrating remote-sensing-based estimates of mean annual land surface
temperatures (MASTs), leaf area index (LAI) and fractional snow cover values,
and decadal mean MAAT date from 152 weather stations with a geographically
weighted regression (GWR). The results reflect a continuous rise of
approximately 0.04 ∘C a−1 in the decadal mean MAAT values over
the past half century. A thermal-condition classification matrix is used to
convert modelled MAATs to permafrost thermal type. Results show that the
climate warming has led to a thermal degradation of permafrost in the past
half century. The total area of thermally degraded permafrost is
approximately 153.76×104 km2, which corresponds to
88 % of the permafrost area in the 1960s. The thermal condition of 75.2 %
of the very cold permafrost, 89.6 % of the cold permafrost, 90.3 % of the
cool permafrost, 92.3 % of the warm permafrost, and 32.8 % of the very
warm permafrost has been degraded to lower levels of thermal condition.
Approximately 49.4 % of the very warm permafrost and 96 % of the likely
thawing permafrost has degraded to seasonally frozen ground. The mean
elevations of the very cold, cold, cool, warm, very warm, and likely thawing
permafrost areas increased by 88, 97, 155, 185, 161, and
250 m, respectively. The degradation mainly occurred from the 1960s to the
1970s and from the 1990s to the 2000s. This degradation may lead to increased
risks to infrastructure, reductions in ecosystem resilience, increased flood risks, and positive climate feedback effects. It therefore affects the
well-being of millions of people and sustainable development at the Third
Pole.
Effects of undercutting and sliding on calving: a global approach applied to Kronebreen, Svalbard
Authors: Vallot Dorothée , Åström Jan , Zwinger Thomas , Pettersson Rickard , Everett Alistair , Benn Douglas I. , Luckman Adrian , van Pelt Ward J. J. , Nick Faezeh , Kohler Jack
Published: February 2018

Abstract. In this paper, we study the effects of basal friction, sub-aqueous
undercutting and glacier geometry on the calving process by combining six
different models in an offline-coupled workflow: a continuum–mechanical ice
flow model (Elmer/Ice), a climatic mass balance model, a simple subglacial
hydrology model, a plume model, an undercutting model and a discrete particle
model to investigate fracture dynamics (Helsinki Discrete Element Model,
HiDEM). We demonstrate the feasibility of reproducing the observed calving
retreat at the front of Kronebreen, a tidewater glacier in Svalbard, during a
melt season by using the output from the first five models as input to HiDEM.
Basal sliding and glacier motion are addressed using Elmer/Ice, while calving
is modelled by HiDEM. A hydrology model calculates subglacial drainage paths
and indicates two main outlets with different discharges. Depending on the
discharge, the plume model computes frontal melt rates, which are iteratively
projected to the actual front of the glacier at subglacial discharge
locations. This produces undercutting of different sizes, as melt is
concentrated close to the surface for high discharge and is more diffuse for
low discharge. By testing different configurations, we show that undercutting
plays a key role in glacier retreat and is necessary to reproduce observed
retreat in the vicinity of the discharge locations during the melting season.
Calving rates are also influenced by basal friction, through its effects on
near-terminus strain rates and ice velocity.
Consistent CryoSat-2 and Envisat Freeboard Retrieval of Arctic and
Antarctic Sea Ice
Authors: Paul Stephan , Hendricks Stefan , Ricker Robert , Kern Stefan , Rinne Eero
Published: February 2018

Abstract. In order to derive long-term changes in sea-ice volume, a multi-decadal sea-ice thickness record is required. CryoSat-2 has showcased the potential of radar altimetry for sea-ice mass-balance estimation over the last years. However, precursor altimetry missions such as Envisat have not been exploited to the same extent so far. Combining both missions to acquire a decadal sea-ice volume data set requires a method to overcome the discrepancies due to different footprint sizes from either pulse-limited or beam-sharpened radar echoes. In this study, we implemented an inter-mission consistent surface-type classification scheme for both hemispheres, based on the waveform pulse peakiness, leading-edge width, and sea-ice backscatter. In order to achieve a consistent retracking procedure, we adapted the Threshold First Maximum Retracker Algorithm, previously used only for CryoSat-2, to develop an adaptive retracker threshold that depends on waveform characteristics. With our method, we produce a global and consistent freeboard data set for CryoSat-2 and Envisat. This novel data set features a maximum monthly difference in the mission-overlap period of 2.2 cm (2.7 cm) for the Arctic (Antarctic) based on all gridded values with spatial resolution of 25 km × 2 km and 50 km × 50 km for the Arctic and Antarctic, respectively.
Extending the life of wind turbine blade leading edges by reducing the tip speed during extreme precipitation events
Authors: Bech Jakob I. , Hasager Charlotte B. , Bak Christian
Published: February 2018

Abstract. Impact fatigue caused by collision with rain droplets, hail stones and other airborne particles, also known as rain erosion, is a severe problem for wind turbine blades. Each impact on the leading edge adds an increment to the accumulated damage in the material. After a number of impacts the leading edge material will crack. This paper presents and supports the hypothesis that the vast majority of the damage accumulated in the leading edge is imposed at extreme precipitation condition events, which occur during a very small fraction of the turbines operation life. By reducing the tip speed of the blades during these events, the service life of the leading edges significantly increases from a few years to the full expected lifetime of the wind turbine. In the worst case at the cost of a negligible reduction of annual energy production (AEP) and in the best case with a significant increase in AEP.