bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimization of Shaft Sleeve Slippage in High-Voltage Circuit Breaker
Operation Mechanism
Authors: Wenqiang Zhao , Haibo Zhang , Shijing Wu , Fangang Meng
Published: November 2015

High-voltage circuit breakers are mechanical switching devices which connect and break current circuits
(operating currents and fault currents) and carry the nominal current in closed position. As a result of multi-running, the
shaft sleeve in operation mechanism could slip and even strip from the shaft at the hinge joint, which decreases the system
reliability. In this work, investigations on the cause of sleeve slippage are proceeded, and the dimension parameters of
shafting components where sleeve slippage occurs are optimized by incorporating a quasi-static mechanical model with
Taguchi method. By developing and analyzing the mechanical model for the shaft sleeve slippage, it indicates that the
sleeve slippage displacement has a same variation tendency with the shaft deflection. Theoretical equations are derived by
using force analysis and superposition method to descript the analytic function of the shaft deflection. As the variables
within the analytic function of the shaft deflection, the diameter and length of the shaft and the corresponding shaft sleeve
length are selected as the control parameters in the optimization model. Moreover, several experiments are conducted by
using the L18 (mixed orthogonal array) design method. Considering that the local mechanical characteristics such as sleeve
strain are difficult to monitor via experimental method, an FEM simulation model is established to give the sleeve
slippage displacement. Different levels of control parameters are introduced into the mechanical model and FEM
simulation according to Taguchi method. The results from signal-to-noise (S/N) and ANOVA analysis (analysis of
variance) reveal that shaft diameter is the most significant factor determining sleeve slippage in high-voltage circuit
breaker operation mechanism, and that a larger diameter of shaft, a shorter shaft length and a longer sleeve length can
reduce the sleeve slippage effectively. Meanwhile, the theoretical model is verified and enhanced by the FEM model.
First integrals and exact solutions of the generalized models of magnetic insulation
Authors: Kosov Alexander , Semenov Edward , Sinitsyn Alexander
Published: November 2015

We suggest generalizations of the mathematical model of magnetic insulation,
described by multidimensional quasi potential ODE system or PDE system with
two-dimensional Laplace operator. Existence conditions of the first integrals
of a certain type for the class of nonlinear quasi potential systems,
including the model vacuum diode are obtained. Integrability of the vacuum
diode models is justified. We find for PDE system the class of exact radially
symmetric solutions given by fractional-rational functions. The class of
systems with variable density, reduced to a similar system with the constant
current density by special transformations is specified. The class of exact
solutions of the non-singular boundary-value problem in annular domain is
found.
Analysis of Quinic Acid and of myo-Inositol in Tobacco
Authors: Moldoveanu SC , Davis MF
Published: November 2015

Quinic acid [D(-)-quinic acid, (1S, 3R,4S,5R)-1,3,4,5-tetrahydroxycyclohexanecarboxylic acid], and inositol [myoinositol, (1R,2R,3S,4S,5R,6S-cyclohexane-1,2,3,4,5,6-hexol or cis-1,2,3,5-trans-4,6-cyclohexane-hexol] are oxygenated compounds well known as tobacco constituents. Although mentioned in the literature as constituents of tobacco leaf as early as 1930, very little information is offered regarding the quantitation of quinic acid and inositol, up to the present day. This study describes a simple procedure for the analysis of quinic acid and myo-inositol in tobacco and reports the levels of these two analytes in various single grade and blended tobaccos from commercial and Kentucky reference cigarettes. The procedure is based on an original LC/MS/MS analysis of the tobacco extract. This method and its validation are described in this paper.

A wide range of levels of the analytes was observed from sample to sample. Burley samples were in general low in both quinic acid and inositol compared to flue-cured tobaccos. The levels of myo-inositol detected in the analyzed samples were consistent with previously reported results for flue-cured tobaccos, but significantly lower than those reported for Burley. Besides myo-inositol, a number of naturally occurring stereoisomers of inositol are known. These include scyllo-, muco-, D-chiro- and neo-inositol. Other isomers are possible, including L-chiro-, allo-, epiand cis-inositol, but they are less common. No previous study has been reported regarding the evaluation of these compounds in tobacco, and the present study indicated that only myo-inositol and D(-)-quinic acid are found in tobacco.
Prevalence of Malocclusion and Orthodontic Treatment Needs in Down Syndrome Sudanese Individuals
Authors: Ibrahim Hiba A. , Abuaffan Amal H.
Published: November 2015

Objective: To determine prevalence of malocclusion and orthodontic treatment needs in Down syndrome individuals among Sudanese population in Khartoum area.Materials & Method: A total of 75 (37 males and 38 females) Down syndrome individuals age ranging from 6-28 years were clinically examined after obtaining their guardian’s consent, malocclusion was determined based on Angle and Incisor classification. Exclusion criteria were included individuals who had history of extraction and orthodontic treatment.Data was analysed by using SPSS Version 17, at an alpha level 0.05 and 95% confidence limits.Result: Angle Class III and Incisor III malocclusion represents the most prevalent type of malocclusions (58.7%) Angle classification, (53.3%) Incisors classification. Angle Class III malocclusion was more frequent among females (60.5%) than in males (56.8%). Themajority of individuals with Down syndrome are in need of orthodontic treatment (85.3%).Conclusion: The prevalence of malocclusion and orthodontic treatment need among Sudanese Down syndrome individuals was high. Angle and Incisor Class III malocclusion representing commonest trait of malocclusion with more frequency in femalesthan males.Key word: down syndrome, Class III malocclusion, orthodontic treatment
Demystifying online personas of Vietnamese young adults on Facebook: A Q-methodology approach
Authors: Dang-Pham Duy , Pittayachawan Siddhi , Nkhoma Mathews
Published: November 2015

As online social networking sites (SNS) are becoming a part of many people’s daily life, they have become a topic of interest that attracts the attention of both academics and practitioners. The users’ behaviours on those sites are complex and have important implications. Individuals can use a wide range of SNS’s functionalities, for example, to socialise and promote their online identities or find friends of common interests. Reckless online behaviours on SNS have been shown to result in breaches of privacy and other risks such as cyber-bullying, cyber-stalking, and job loss. As a result, there are many concerns over these problems that prevent SNS from reaching their full potential. Given the vast number of user’s concerns, identified by prior studies, there is a need to explore a typology of users that classifies online personas. This typology would reveal more about the users’ needs and help improve their experience on SNS. To achieve that goal, we collected data from fourteen Vietnamese young adults of different backgrounds who use Facebook, which was then analysed with Q factor analysis. The findings suggested three distinctive online personas that include the Outgoing Connector, the Reserved Trustor, and the Threats Perceiver. Implications for marketing tactics and design of better users’ experiences on social networking sites were discussed, and the proposed typology could serve as a starting point for future research to further explore the different types of social media’s users.
Effects of burnishing parameters on the quality and microhardness of flat die surfaces
Authors: Müftüoğlu Hikmet Sadi , Malyer Elif
Published: November 2015

In this study, the burnishing process is recommended as finishing operation of flat die surfaces for improving not only surface quality but also mechanical properties of milled die surfaces. This technique can be applied after milling operations in CNC milling centers with a single fastening that increases the accuracy of the die geometry. To determine both the usability of the process on flat die surfaces and the influence of process parameters, a simple burnishing tool with a fixed deformation element was designed and constructed. The CNC milling center was used for burnishing operations. The burnishing process was employed using a constant spindle speed on a flat surface. Burnishing feed rate, stepover, penetration depth, the number of passes, burnishing direction and coolant were chosen as process parameters. First, optimum parameters were stated, then macro and microstructure of the burnished surfaces were examined, and roughness and hardness measurements of surfaces were carried out. Results show that burnishing increased the surface quality and microhardness of flat milled surface. The penetration depth has the maximum and stepover has the minimum effect on surface quality. The coolant has the highest effect on microhardness. The burnishing direction has a significant effect on both microhardness and surface quality. It can be briefly stated that burnishing is an economic and feasible surface treatment process for finishing operations of die surfaces.
High-precision deformation and damage development assessment of composite materials by high-speed camera, high-frequency impulse and digital image correlation techniques
Authors: Myslicki Sebastian , Ortlieb Markus , Frieling Gerrit , Walther Frank
Published: November 2015

Although composite materials like wood, vulcanized fiber and carbon reinforced plastic (CFRP) are already investigated by means of their mechanical properties, the abrupt fracture mechanism as well as the deformation behavior right before and after fracture has not been investigated. However, it is marginally investigated for CFRP because of the quite high fracture speed. The knowledge about the damage evolution as the crack start and propagation can help to improve the strength and sensitivity to fracture by improving the materials structure and to utilize these materials for structural applications. For the investigated materials, fracture happens abruptly as it is the nature of composites and the detailed fracture mechanisms could not be detected by conventional measurement techniques. Therefore, an innovative combination of testing devices is presented which is able to fill this gap. Tensile tests were performed to receive conventional stress-strain curves. At the fracture stage, a high-speed camera recorded the fracture process. This information could be combined with digital image correlation (DIC) to visualize the deformation behavior. At the same time acoustic emission (AE) was used to detect the spectrum of mechanical vibrations which gives information about the released energy due to fracture. The challenging triggering of the high-speed camera was solved for each material individually. By using improved light sources, the recording speed could be set up to 2 million frames per second (Mfps). The investigations show different fracture mechanisms for each composite. Wood and vulcanized fiber were also investigated in different directions due to their anisotropy.
Diagnostic Approach to Limp in Children
Authors: Shah Ami P. , Indra Sean , Kannikeshwaran Nirupama , Hartwig Earl , Kamat Deepak
Published: November 2015

“Limp” is a common complaint of children presenting to the emergency department or physician's office. For most patients presenting with limp, the diagnosis and management can be completed in the physician's office or emergency department by gathering a detailed history, performing a careful physical examination, and requesting a few laboratory and imaging studies. This article reviews common causes of atraumatic limp in children and discusses the evaluation and management of these conditions.

[
Pediatr Ann
. 2015;44(12):548–550, 552–554, 556.]
Las asociaciones de ostrácodos en secuencias aluviales como indicadores de cambios ambientales holocenos (Bardenas Reales de Navarra, Cuenca del Ebro, NE Península Ibérica)
Authors: Martínez-García B. , Suarez-Hernando O. , Rodríguez-Lázaro J. , Pascual A. , Ordiales A. , Murelaga X. , Sancho C. , Muñoz A. , Osácar C.
Published: November 2015

En este trabajo se estudian las asociaciones de ostrácodos identificadas en tres unidades aluviales preservadas en Bardenas Reales de Navarra (Cuenca del Ebro, NE Península Ibérica), para reconstruir la evolución paleoambiental de esta área durante el Holoceno final. Las especies de ostrácodos más comunes en las muestras estudiadas son Ilyocypris bradyi Sars y Paralimnocythere aff. psammophila (Flössner), acompañadas por Pseudocandona albicans (Brady). Las variaciones en su abundancia relativa a lo largo de dichas unidades aluviales permiten caracterizar cambios internos en el ambiente de depósito. Así, la unidad depositada entre 4763±87 y 2848±55 años cal. BP presenta como especie más abundante a I. bradyi, lo que indica la existencia de pequeños arroyos o riachuelos con agua corriente que se desarrollaron probablemente en llanuras de inundación fluviales. Sin embargo, de 2848±55 a 836±65 años cal. BP Paralimnocythere aff. psammophila es la especie dominante, representando el establecimiento de un medio acuático efímero y de aguas estancadas, posiblemente relacionado con condiciones climáticas más áridas (Anomalía Climática Medieval). Finalmente, la asociación de ostrácodos identificada en el Reciente (191±97 a 127±82 años cal. BP) está constituida principalmente por I. bradyi, que indicaría la presencia de nuevo de aguas corrientes. Esta última asociación parece estar vinculada a la influencia de condiciones climáticas húmedas y frías (Pequeña Edad del Hielo) durante el Reciente en esta área. Por lo tanto, la evolución paleoambiental para el Holoceno final de Bardenas Reales de Navarra, identificada a partir de las asociaciones de ostrácodos, muestra una buena correlación con los cambios climáticos rápidos holocenos deducidos en otros registros continentales del NE de la Península Ibérica.
Attitudes towards music as a means of therapy: can it help to overcome depression and/or cardiovascular disease?
Authors: Giannouli Vaitsa
Published: November 2015

 

 
Pain clinic referral to psychological services best addressed with collaboration
Authors: Sexton-Radek Kathy , Chami A. Tony
Published: November 2015

A case study of a middle aged female with severe musculoskeletal medical conditions causing severe pain is presented. The referral for psychological services was conducted in concordance with the medical treatments. In this case, the complex nature of the severe musculoskeletal medical conditions necessitated intensive care and the collaborative communications provided this to the patient. A tabulation of representative treatments is provided with an explanation of the nature of the collaboration. Outcome data in terms of patient self-reported pain ratings and sleep logging provided evidence of a mild improvement and stability where more negative findings, given the complexity of the medical conditions was expected.
The in-house psychologist: do we speak the same language? Short report of a qualitative practice project
Authors: Schoenmakers Birgitte , De Lepeleire Jan
Published: November 2015

Interdisciplinary collaboration is gaining importance. Although general practices (GP’s) have a comprehensive experience in collaboration with psychologists, research on this topic is scarce. In house referrals to a psychologist are assumed to lower the thresholds for patients and GP’s. In this study it was investigated whether the GP’s reasons to refer in were accordance with the treatment strategy of the residing psychologist. The study is performed in a retrospective, observational cross section design. The studied population were the residing psychologist and GP’s. Both were asked to complete a questionnaire. Outcome measures where the referral reasons of the GP’s and the treatment strategy of the psychologist. A total sample of 92 patients of 6 GP’s was studied. Over 60% of the patients were referred for counseling but only in 25% of the cases this proposal was carried out by the psychologist. Overall, the referral reasons of the GP’s were not in accordance with the treatment strategy of the psychologist. A close collaboration and communication between general practitioners and psychologists is both difficult and indispensable. This practice research demonstrated that the referral motives of the GP’s usually do not correspond to the treatment policy of the psychologist. This observation is partly explained by a lack of understanding of the GP in the treatment strategies of the psychologists. Another part of the explanation is that there is a pre-selection of the GPs referrals rather influenced by patient characteristics than by pathology.
Do psychological factors help to reduce body mass in obesity or is it vice versa? Selected psychological aspects and effectiveness of the weight-loss program in the obese patients
Authors: Bąk-Sosnowska Monika , Pawlak Adam , Skrzypulec-Plinta Violetta
Published: November 2015

The aim of this study was to assess the strength and direction of the correlation between cognitive appraisal, emotional state, social functioning and the effectiveness of a weight-loss program undertaken by obese subjects. The out-patient weight-loss program encompassed 150 obese women. Assessments were carried out at four time points: at the start of the weight-loss program and then after a 5%, 10% and a 15% reduction of the initial body mass. The research tools used were: a survey, the Situation Appraisal Questionnaire (SAQ), the Emotional State Questionnaire (ESQ), and the Q-Sort Social Functioning Questionnaire. The cognitive appraisal, emotional state and social functioning of the study group changed significantly (P<0.001). Significantly more individuals with a 15% body mass reduction, as compared with individuals with no body mass reduction, had an early obesity onset, i.e. at the age of <10 years old (P<0.001). Significantly more individuals with no body mass reduction, compared with individuals with a 15% reduction, had a later obesity onset, i.e. between the ages of 20 and 30 (P<0.001) and between 50 and 60 (P<0.001). Significantly more individuals with a 15% body mass reduction, compared with individuals with no mass reduction, had previously experienced the jojo effect (P<0.001) and had successfully lost weight (P<0.001). Significantly more individuals with no body mass reduction, compared with individuals with a15% reduction, had a history of unsuccessful attempts at reducing body mass (P<0.001). We conclude that the attitude of obese patients towards a weight-loss program is not a deciding factor for its effectiveness. As body mass reduces, the attitude improves.
Adherence and physical activity
Authors: Theofilou Paraskevi , Reyes Saborit Aymara
Published: November 2015

   
Investigation of aggravating psychosocial factors on health and predictability of smoking and alcohol use in post adolescent students
Authors: Barmpagianni Effrosyni , Travlos Antonios , Kalokairinou Athina , Sachlas Athanasios , Zyga Sofia
Published: November 2015

Purpose of this study is to explore those factors which affect the health of students in postadolescent age, focusing on smoking and alcohol use, especially in regard to ways of predicting adoption of this behavior and its frequency to detect future users of tobacco and alcohol use but also high-risk groups, i.e. those people who are led to abuses. On the basis of the research part is the Theory of Planned Behaviour, the axes of which are to be investigated. Specifically, the factors evaluated, except for population parameters, behavioral attitudes, i.e. attitudes towards the behavior of tobacco use and alcohol regulations subjective perceptions and perceptions of control, perceived behavioral control and self-efficacy. Intention is explored to continue or start using tobacco and alcohol in the future and evaluate the behavior. The sample consisted of 138 students of postadolescent age, 18-25 years of both sexes, all of the University of Peloponnese and the Technological Educational Institute of Kalamata, Department of Sparta, Greece. The results of a series of statistical analysis, via SPSS 21.0 statistical program revealed the predictive power of perceived behavioral control and subjective norms to the intention of interpreting 64% of the variance of the latter, of the attitudes toward alcohol in relation to intention that interpret 69% of the variance, of the normative beliefs toward smoking with 69% range of interpretation to the dependent variable, of the perceived behavioral control of smoking with 72% and of the attitudes toward smoking with 77% of interpretation. The results demonstrate the significance and application in universities and technological educational institutes appropriate primary preventive interventions for students nonusers of tobacco and alcohol and appropriate programs of secondary and tertiary prevention in heavy users of tobacco and alcohol use and high-risk individual.
Perceptions of educators regarding the implementation of the health promotion programme manuals for children in schools in Makapanstad, South Africa
Authors: Peu Doriccah , Mataboge Sanah , Ladzani Rendani , Wessels Lene , Mostert-Wentzel Karien , Seane Neo
Published: November 2015

Background: Health promoting schools focus on, amongst other things, preventing leading causes of death such as Sexually Transmitted Infections (STI’s), Human Immune Deficiency Virus (HIV) and Acquired Immunodeficiency Syndrome (AIDS), a sedentary lifestyle and creating conditions that are conducive to health through health education.Aim: This study explored the perceptions of educators regarding implementation of the health promotion programme manuals in selected schools of the Makapanstad community.Method: A qualitative, exploratory, descriptive and contextual design was utilised in this study. Four schools were selected to participate in the study. Purposive sampling was used to select educators from these schools who were actively involved in the health promotion programme. Data collection was taken through focus group interviews. One focus group comprised of eight participants who were interviewed three times. The focus group interviews were conducted until data were saturated. Data were analysed using an adaptation of Tesch’s method. The eight steps of Tesch’s method enabled researchers to systematically analyse and organise data using colour coding to develop data into categories, sub-categories and themes.Results and conclusion: The themes that emerged during data analysis were: the perceptions of educators regarding health promotion programme manuals before implementation of manuals, and the perceptions of educators regarding health promotion programme manuals after the implementation of manuals. Introducing health promotion materials to the schools served as a point of departure for developing personal skills and creating a supportive environment for health in schools. The health promotion manual assisted the educators to attain appropriate health promotion information.
Gliomatosis cerebri: Case series of six cases with review of literature
Authors: Yerramneni Vamsi Krishna , Vinjamuri Srinivasa Rao , Purohit A. K. , Sundaram C.
Published: November 2015

Background Gliomatosis cerebri is characterized by diffuse infiltration of glial cells with preservation of neuronal architecture. It is an uncommon glial neoplasm of astrocytic origin that occurs in adults and is exceedingly rare in children. Materials and Methods: The authors retrospectively analyzed the data of 6 patients of gliomatosis cerebri operated between 2007 and 2012. Result: All patients underwent surgical decompression, followed by chemoradiotherapy. The survival ranged between 3 and 45 months. The mean survival was 18.5 years. Conclusion: Performance scores at presentation and the nonglioblastomatous histology seems to favorably affect the prognosis. Larger studies are required to comment on the role of combination of surgery, chemoradiotherapy as a treatment modality.
La ricostruzione tridimensionale e il restauro virtuale di una tomba etrusca dipinta dell’Etruria meridionale interna: la “Grotta Dipinta” di Pranzovico (Viterbo)
Authors: Limoncelli Massimo , Scardozzi Giuseppe
Published: November 2015

The paper concerns the 3D reconstruction and virtual restoration of a painted rock-cut chamber tombs located in the interior of Southern Etruria (Viterbo Province, Central Italy). The tomb was discovered in 1901 in a place named Pranzovico and it dates from the mid-fifth century BC; it has a cross plan with central atrium (decorated with paintings) and three chambers in which there are the rock-cut funerary beds. The paintings have been largely destroyed by illegal excavators in the days immediately following the discovery; during the 20th century it was damaged due to agricultural works in the surroundings and now it is partially filled up. Its 3D reconstruction is based on the scarce remains preserved, the plan and drawings of paintings made at the time of discovery and the comparison with other tombs from Tarquinia and Chiusi.
A Reconstruction and Representation System for 3D Digital Archaeological Documentation – A Case Study of Dahecun Archaeological Site in China
Authors: Xiao Jinliang , Shang Jin , Gao Ming , Zhang Jianhua , Li Jianhe
Published: November 2015

In Dahecun, a famous archaeological site in China, the cultural strata have accumulated up to 12.5 meters, including archaeological remains covering 3,300 years. In order to improve the precision and convenience of archaeological work, a digitally aided 3D archaeological reconstruction and representation system is designed for the support of archaeological work and subsequent research and virtual reconstruction and representation of immediate site information and research output. The system shall benefit archaeologists and researchers as well as the general population with easy access to archaeological information.
Feedbacks of dust and boundary layer meteorology during a dust storm in the eastern Mediterranean
Authors: Rémy S. , Benedetti A. , Bozzo A. , Haiden T. , Jones L. , Razinger M. , Flemming J. , Engelen R. J. , Peuch V. H. , Thepaut J. N.
Published: November 2015

Abstract. Aerosols affect the atmosphere through direct interaction with short-wave and long-wave radiation and the microphysical properties of clouds. In this paper we report in detail on several mechanisms by which the short-term impact of dust on surface radiative fluxes can affect the dust loading of the atmosphere via modification of boundary-layer meteorology. This in turn affects the aerosol radiative forcing itself. Examples of these feedbacks between dust and boundary layer meteorology were observed during a series of dust storms in the Sahara and the eastern Mediterranean in April 2012. These case studies have been analysed using the Monitoring Atmospheric Composition and Climate – Interim Implementation (MACC-II) system. The radiative fluxes in the short-wave and long-wave spectra were both significantly affected by the prognostic aerosol–radiation interaction, which in turn impacted the meteorological simulation. Reduced incoming solar radiation below the aerosol layers led to a decrease in maximum surface temperatures and to a more stable thermal stratification of the lower atmosphere. This in turn forced weaker surface wind speeds and eventually smaller dust emissions. Moreover, we also observed a secondary impact of the aerosol radiative forcing, whereby horizontal gradients of surface temperature were increased at the edge of the dust plume, which led to local increases of surface wind speeds due to the thermal wind effect. The differentiated impact of the aerosol layer on surface pressure also contributed to the increase in surface wind speed and dust production in the same area. Enhanced long-wave radiative fluxes by the dust mass were associated with opposite processes. Less stable thermal stratification at night, brought mainly by higher minimum temperatures at the surface, caused stronger surface winds. At the edge of the dust storm, weaker horizontal temperature and pressure gradients forced lower winds and reduced dust production. Regarding dust emissions, short-wave radiative forcing had a larger impact than long-wave radiative forcing, corroborating several previous studies. For surface temperature, short-wave and long-wave contribution were close in intensity. These feedbacks were amplified when using data assimilation to build the aerosol analysis of the MACC-II global system. This led to an improvement in the short-term forecasts of thermal radiative fluxes and surface temperatures.
Characteristics of gravity waves generated in a baroclinic instability simulation
Authors: Kim Y.-H. , Chun H.-Y. , Park S.-H. , Song I.-S. , Choi H.-J.
Published: November 2015

Abstract. An idealized baroclinic instability case is simulated using a ~ 10 km resolution global model to investigate the characteristics of gravity waves (GWs) generated in the baroclinic life cycle. Three groups of GWs (W1–W3) appear around the high-latitude surface trough at the mature stage of the baroclinic wave. They have horizontal and vertical wavelengths of 40–400 and 2.9–9.8 km, respectively, in the upper troposphere. The two-dimensional phase-velocity spectrum of the waves is arc-shaped with a peak at 17 m s−1 eastward, which is difficult for the waves to propagate upward through the tropospheric westerly jet. At the breaking stage of the baroclinic wave, a midlatitude surface low is isolated from the higher-latitude trough, and two groups of quasi-stationary GWs (W4 and W5) appear near the surface low. These waves have horizontal and vertical wavelengths of 60–400 and 4.9–14 km, respectively, and are able to propagate vertically for long distances. The generation mechanism of the simulated GWs is discussed.
Microphysics-based black carbon aging in a global CTM: constraints from HIPPO observations and implications for global black carbon budget
Authors: He C. , Li Q. , Liou K. N. , Qi L. , Tao S. , Schwarz J. P.
Published: November 2015

Abstract. We develop and examine a microphysics-based black carbon (BC) aerosol aging scheme that accounts for condensation and coagulation processes in a global 3-D chemical transport model (GEOS-Chem) by interpreting the BC measurements from the HIAPER Pole-to-Pole Observations (HIPPO, 2009–2011) using the model. We convert aerosol mass in the model to number concentration by assuming lognormal aerosol size distributions and compute the microphysical BC aging rate explicitly from the condensation of soluble materials onto hydrophobic BC and the coagulation between hydrophobic BC and preexisting soluble particles. The resulting aging rate is ∼ 4 times higher in the lower troposphere over source regions than that from a fixed aging scheme with an e-folding time of 1.2 days. The higher aging rate reflects the large emissions of sulfate-nitrate and secondary organic aerosol precursors hence faster BC aging through condensation and coagulation. In contrast, the microphysical aging is more than fivefold slower than the fixed aging in remote regions, where condensation and coagulation are weak. Globally BC microphysical aging is dominated by condensation, while coagulation contribution is largest over East China, India, and Central Africa. The fixed aging scheme results in an overestimate of HIPPO BC throughout the troposphere by a factor of 6 on average. The microphysical scheme reduces this discrepancy by a factor of ∼ 3, particularly in the middle and upper troposphere. It also leads to a threefold reduction in model bias in the latitudinal BC column burden averaged along the HIPPO flight tracks, with largest improvements in the tropics. The resulting global annual mean BC lifetime is 4.2 days and BC burden is 0.25 mg m-2, with 7.3 % of the burden at high altitudes (above 5 km). Wet scavenging accounts for 80.3 % of global BC deposition. We find that in source regions the microphysical aging rate is insensitive to aerosol size distribution, condensation threshold, and chemical oxidation aging, while it is the opposite in remote regions, where the aging rate is orders of magnitude smaller. As a result, global BC burden and lifetime show little sensitivity (< 5 % change) to these three factors.
A comparative study of GPS ionospheric scintillations and ionogram spread F over Sanya
Authors: Zhang Y. , Wan W. , Li G. , Liu L. , Hu L. , Ning B.
Published: November 2015

Abstract. We analyze the data recorded during December 2011–November 2012 by a digital ionosonde and a GPS (Global Positioning System) scintillation and (total electron content) TEC receiver collocated at Sanya (109.6° E, 18.3° N; dip lat. 12.8° N), a low-latitude station in the Chinese longitude sector, to carry out a comparative study of ionospheric scintillations and spread F. A good consistency between the temporal variations of GPS scintillation (represented by the S4 index) and of ionogram spread F (represented by the QF index) is found in the pre-midnight period during equinox. However in the post-midnight period during equinox and in the period from post-sunset to pre-sunrise during June solstice, moderate spread F is seen without concurrent GPS scintillation. The possible cause responsible for the difference between post-midnight GPS scintillation and spread F during equinox could be due to the decaying of 400 m scale irregularities associated with equatorial spread F. Regarding the irregularities producing moderate QF and low S4 indices during June solstice, we suggest that the frequently observed sporadic E (Es) layer and the medium-scale traveling ionospheric disturbances (MSTIDs) over Sanya could play important roles in triggering the June solstitial spread-F events.
Quantifying regional, time-varying effects of cropland and pasture on vegetation fire
Authors: Rabin S. S. , Magi B. I. , Shevliakova E. , Pacala S. W.
Published: November 2015

Abstract. The global extent of agriculture demands a thorough understanding of the ways it impacts the Earth system through the modification of both the physical and biological characteristics of the landscape as well as through emissions of greenhouse gases and aerosols. People use fire to manage cropland and pasture in many parts of the world, impacting both the timing and amount of fire. So far, much previous research into how these land uses affect fire regimes has focused on either individual small regions or global patterns at annual or decadal scales. Moreover, because pasture is not mapped globally at high resolution, the amount of fire associated with pasture has never been quantified as it has for cropland. The work presented here resolves the effects of agriculture – including pasture – on fire on a monthly basis for regions across the world, using globally gridded data on fire activity and land use at 0.25° resolution. The first global estimate of pasture-associated fire reveals that it accounts for over 40 % of annual burned area. Cropland, generally assumed to reduce fire occurrence, is shown to enhance or suppress fire at different times of year within individual regions. These results bridge important gaps in the understanding of how agriculture and associated management practices influence vegetation fire, enabling the next generation of vegetation and Earth system models more realistically incorporate these anthropogenic effects.
Spatial distribution and sources of organic carbon in the surface sediment of Bosten Lake, China
Authors: Yu Z. T. , Wang X. J. , Zhang E. L. , Zhao C. Y. , Liu X. Q.
Published: November 2015

Abstract. Lake sediment is an important carbon reservoir. However, little is known on the dynamics and sources of sediment organic carbon in Bosten Lake. We collected 13 surface (0–2 cm) sediment samples in Bosten Lake and analyzed total organic carbon (TOC), total nitrogen (TN), stable carbon isotopic composition in TOC (δ13Corg), and grain size. We found a large spatial variability in TOC content (1.8–4.4 %) and δ 13Corg value (−26.77 to −23.98 ‰). Using a three-end-member mixing model with measured TOC : TN ratio and δ13Corg, we estimated that 54–90 % of TOC was from autochthonous sources. Higher TOC content (> 3.7 %) was found in the east and central-north sections and near the mouth of the Kaidu River, which was attributable to allochthonous, autochthonous plus allochthonous, and autochthonous sources, respectively. The lowest TOC content was found in the mid-west section, which might be a result of high kinetic energy levels. Our study indicated that the spatial distribution of sediment TOC in the Bosten Lake was influenced by multiple and complex processes.
Climatic and insolation control on the high-resolution total air content in the NGRIP ice core
Authors: Eicher O. , Baumgartner M. , Schilt A. , Schmitt J. , Schwander J. , Stocker T. F. , Fischer H.
Published: November 2015

Abstract. Because the total air content (TAC) of polar ice is directly affected by the atmospheric pressure, its record in polar ice cores was considered as a proxy for past ice sheet elevation changes. However the Antarctic ice core TAC record is known to also contain an insolation signature, although the underlying physical mechanisms are still a matter of debate. Here we present a high-resolution TAC record over the whole North Greenland Ice Core Project ice core, covering the last 120 000 years, which independently supports an insolation signature in Greenland. Wavelet analysis reveals a clear precession and obliquity signal similar to previous findings on Antarctic TAC, with different insolation history. In our high-resolution record we also find a decrease of 3–5 % (3–4.2 mL kg−1) in TAC as a response to Dansgaard-Oeschger-Events (DO-events). TAC starts to decrease in parallel to increasing Greenland surface temperature and slightly before CH4 reacts to the warming, but also shows a two-step decline that lasts for several centuries into the warm phase/interstadial. The TAC response is larger than expected considering only local temperature and atmospheric pressure as a driver, pointing to transient firnification response caused by the accumulation-induced increase in the load on the firn at bubble close-off, while temperature changes deeper in the firn are still small.
Macropore flow at the field scale: predictive performance of empirical models and X-ray CT analyzed macropore characteristics
Authors: Naveed M. , Moldrup P. , Schaap M. , Tuller M. , Kulkarni R. , Vögel H.-J. , Wollesen de Jonge L.
Published: November 2015

Abstract. Predictions of macropore flow is important for maintaining both soil and water quality as it governs key related soil processes e.g. soil erosion and subsurface transport of pollutants. However, macropore flow currently cannot be reliably predicted at the field scale because of inherently large spatial variability. The aim of this study was to perform field scale characterization of macropore flow and investigate the predictive performance of (1) current empirical models for both water and air flow, and (2) X-ray CT derived macropore network characteristics. For this purpose, 65 cylindrical soil columns (6 cm diameter and 3.5 cm height) were extracted from the topsoil (5 to 8.5 cm depth) in a 15 m × 15 m grid from an agricultural loamy field located in Silstrup, Denmark. All soil columns were scanned with an industrial CT scanner (129 μm resolution) and later used for measurements of saturated water permeability, air permeability and gas diffusivity at −30 and −100 cm matric potentials. Distribution maps for both water and air permeabilities and gas diffusivity reflected no spatial correlation irrespective of the soil texture and organic matter maps. Empirical predictive models for both water and air permeabilities showed poor performance as they were not able to realistically capture macropore flow because of poor correlations with soil texture and bulk density. The tested empirical model predicted well gas diffusivity at −100 cm matric potential, but relatively failed at −30 cm matric potential particularly for samples with biopore flow. Image segmentation output of the four employed methods was nearly the same, and matched well with measured air-filled porosity at −30 cm matric potential. Many of the CT derived macropore network characteristics were strongly interrelated. Most of the macropore network characteristics were also strongly correlated with saturated water permeability, air permeability, and gas diffusivity. The correlations between macropore network characteristics and macropore flow parameters were further improved on dividing soil samples into samples with biopore and matrix flow. Observed strong correlations between macropore network characteristics and macropore flow highlighted the need of further research on numerical simulations of macropore flow based on X-ray CT images. This could pave the way for the digital soil physics laboratory in the future.
Monitoring infiltration processes with high-resolution surface-based Ground-Penetrating Radar
Authors: Klenk P. , Jaumann S. , Roth K.
Published: November 2015

Abstract. In this study, we present a series of high resolution Ground-Penetrating Radar (GPR) measurements monitoring two artificially induced infiltration pulses into two different sands with dual-frequency ground-based GPR. After the application of the second infiltration pulse, the water table in the subsoil was raised by pumping in water from below. The longterm relaxation of the system was then monitored over the course of several weeks. We focused on the capillary fringe reflection and on observed variations in soil water content as derived from direct wave travel times. We discuss the advantages of this dual-frequency approach and show the attainable precision in longterm monitoring of such relaxation processes. Reaching a relative precision of better than 0.001 [–] in water content, we can clearly discern the relaxation of the two investigated sands.
The challenge and future of rocky desertification control in Karst areas in Southwest China
Authors: Zhang J. Y. , Dai M. H. , Wang L. C. , Zeng C. F. , Su W. C.
Published: November 2015

Abstract. Karst rocky desertification occurs after vegetation deteriorates as a result of intensive land use, which leads to severe water loss and soil erosion and exposes basement rocks, creating a rocky landscape. The karst rocky desertification is found in humid areas in Southwest China, the region most seriously affected by rocky desertification in the world. In order to promote ecological restoration and help peasants out of poverty, the Chinese government carried out the first phase of a rocky desertification control project from 2006 to 2015, which initially contained the expansion of rocky desertification. Currently, the Chinese government is prepared to implement the second phase of the rocky desertification control project, and therefore it is essential to summarize the lessons learned over the last ten years of the first phase. In this paper, we analyze the driving social and economic factors behind rocky desertification, summarize the scientific research on rocky desertification in the region, and finally identify the main problems facing rocky desertification control. In addition, we put forward several policy suggestions that take into account the perspective of local peasants, the scientific research, and China's economic development and urbanization process. These suggestions include: promoting the non-agriculturalization of household livelihoods, improving ecological compensation, strengthening the evaluation of rocky desertification control and dynamic monitoring, and strengthening research on key ecological function recovery technologies and supporting technologies.
A new methodology to simulate subglacial deformation of water-saturated granular material
Authors: Damsgaard A. , Egholm D. L. , Piotrowski J. A. , Tulaczyk S. , Larsen N. K. , Brædstrup C. F.
Published: November 2015

Abstract. The dynamics of glaciers are to a large degree governed by processes operating at the ice–bed interface, and one of the primary mechanisms of glacier flow over soft unconsolidated sediments is subglacial deformation. However, it has proven difficult to constrain the mechanical response of subglacial sediment to the shear stress of an overriding glacier. In this study, we present a new methodology designed to simulate subglacial deformation using a coupled numerical model for computational experiments on grain-fluid mixtures. The granular phase is simulated on a per-grain basis by the discrete element method. The pore water is modeled as a compressible Newtonian fluid without inertia. The numerical approach allows close monitoring of the internal behavior under a range of conditions. Our computational experiments support the findings of previous studies where the rheology of a slowly deforming water-saturated granular bed in the steady state generally conforms to the rate-independent plastic rheology. Before this so-called critical state, deformation is in many cases accompanied by volumetric changes as grain rearrangement in active shear zones changes the local porosity. For previously consolidated beds porosity increases can cause local pore-pressure decline, dependent on till permeability and shear rate. We observe that the pore-water pressure reduction strengthens inter-granular contacts, which results in increased shear strength of the granular material. In contrast, weakening takes place when shear deformation causes consolidation of dilated sediments or during rapid fabric development. Both processes of strengthening and weakening depend inversely on the sediment permeability and are transient phenomena tied to the porosity changes during the early stages of shear. We find that the transient strengthening and weakening in turn influences the distribution of shear strain in the granular bed. Dilatant strengthening has the ability to distribute strain during early deformation to large depths, if sediment dilatancy causes the water pressure at the ice–bed interface to decline. Oppositely, if the ice–bed interface is hydrologically stable the strengthening process is minimal and instead causes shallow deformation. The depth of deformation in subglacial beds thus seems to be governed by not only local grain and pore-water feedbacks but also larger-scale hydrological properties at the ice base.