bluuebunny/crossref_metadata_2025 huggingface dataset:
Rosseland and Flux Mean Opacities for Compton Scattering
Authors: Poutanen Juri
Published: January 2017

Rosseland mean opacity plays an important role in theories of stellar evolution and X-ray burst models. In the high-temperature regime, when most of the gas is completely ionized, the opacity is dominated by Compton scattering. Our aim here is to critically evaluate previous works on this subject and to compute the exact Rosseland mean opacity for Compton scattering over a broad range of temperature and electron degeneracy parameter. We use relativistic kinetic equations for Compton scattering and compute the photon mean free path as a function of photon energy by solving the corresponding integral equation in the diffusion limit. As a byproduct we also demonstrate the way to compute photon redistribution functions in the case of degenerate electrons. We then compute the Rosseland mean opacity as a function of temperature and electron degeneracy and present useful approximate expressions. We compare our results to previous calculations and find a significant difference in the low-temperature regime and strong degeneracy. We then proceed to compute the flux mean opacity in both free-streaming and diffusion approximations, and show that the latter is nearly identical to the Rosseland mean opacity. We also provide a simple way to account for the true absorption in evaluating the Rosseland and flux mean opacities.
Analysis of Low Excitation HDO Transitions toward the High-mass Star-forming Regions G34.26+0.15, W51e1/e2, and W49N
Authors: Kulczak-Jastrzȩbska Magda
Published: January 2017

We present observations of the ground state 10,1–00,0 rotational transition of HDO at 464.925 GHz and the 11,0–10,1 transition at 509.292 GHz, toward three high-mass star-forming regions: G34.26+0.15, W49N, and W51e1/e2, carried out with the Caltech Submillimeter Observatory. For the first time, the latter transition is observed from the ground. The spectra are modeled, together with observations of higher-energy HDO transitions, as well as submillimeter dust continuum fluxes from the literature, using a spherically symmetric radiative transfer model to derive the radial distribution of the HDO abundance in the target sources. The abundance profile is divided into an inner hot core region, with kinetic temperatures higher than 100 K, and a cold outer envelope with lower kinetic temperatures. The derived HDO abundance with respect to H2 is (0.3–3.7) × 10−8 in the hot inner region (T > 100 K) and (7.0–10.0) × 10−11 in the cold outer envelope. We also used two

fundamental transitions to constrain the H2O abundances in the outer envelopes. The HDO/H2O ratios in these cold regions are found to be (1.8–3.1) × 10−3 and consequently are higher than in the hot inner regions of these sources.
New Solar Irradiance Measurements from the Miniature X-Ray Solar Spectrometer Cubesat
Authors: Woods Thomas N. , Caspi Amir , Chamberlin Phillip C. , Jones Andrew , Kohnert Richard , Mason James Paul , Moore Christopher S. , Palo Scott , Rouleau Colden , Solomon Stanley C. , Machol Janet , Viereck Rodney
Published: January 2017

The goal of the Miniature X-ray Solar Spectrometer (MinXSS) CubeSat is to explore the energy distribution of soft X-ray (SXR) emissions from the quiescent Sun, active regions, and during solar flares and to model the impact on Earth's ionosphere and thermosphere. The energy emitted in the SXR range (0.1–10 keV) can vary by more than a factor of 100, yet we have limited spectral measurements in the SXRs to accurately quantify the spectral dependence of this variability. The MinXSS primary science instrument is an Amptek, Inc. X123 X-ray spectrometer that has an energy range of 0.5–30 keV with a nominal 0.15 keV energy resolution. Two flight models have been built. The first, MinXSS-1, has been making science observations since 2016 June 9 and has observed numerous flares, including more than 40 C-class and 7 M-class flares. These SXR spectral measurements have advantages over broadband SXR observations, such as providing the capability to derive multiple-temperature components and elemental abundances of coronal plasma, improved irradiance accuracy, and higher resolution spectral irradiance as input to planetary ionosphere simulations. MinXSS spectra obtained during the M5.0 flare on 2016 July 23 highlight these advantages and indicate how the elemental abundance appears to change from primarily coronal to more photospheric during the flare. MinXSS-1 observations are compared to the Geostationary Operational Environmental Satellite (GOES) X-ray Sensor (XRS) measurements of SXR irradiance and estimated corona temperature. Additionally, a suggested improvement to the calibration of the GOES XRS data is presented.
Globular Clusters as Tracers of Fine Structure in the Dramatic Shell Galaxy NGC 474
Authors: Lim Sungsoon , Peng Eric W. , Duc Pierre-Alain , Fensch Jérémy , Durrell Patrick R. , Harris William E. , Cuillandre Jean-Charles , Gwyn Stephen , Lançon Ariane , Sánchez-Janssen Rúben
Published: January 2017

Globular clusters (GCs) are some of the most visible tracers of the merging and accretion histories of galaxy halos. Metal-poor GCs, in particular, are thought to arrive in massive galaxies largely through dry, minor merging events, but it is rare to see a direct connection between GCs and visible stellar streams. NGC 474 is a post-merger early-type galaxy with dramatic fine structures made of concentric shells and radial streams that have been more clearly revealed by deep imaging. We present a study of GCs in NGC 474 to better establish the relationship between merger-induced fine structure and the GC system. We find that many GCs are superimposed on visible streams and shells, and about 35% of GCs outside

are located in regions of fine structure. The spatial correlation between GCs and fine structure is significant at the 99.9% level, which shows that this correlation is not coincidental. The colors of GCs on fine structures are mostly blue, and we also find an intermediate-color population that is dominant in the central region and that will likely passively evolve to have colors consistent with a traditional metal-rich GC population. The association of the blue GCs with fine structures is direct confirmation that many metal-poor GCs are accreted onto massive galaxy halos through merging events and that the progenitors of these mergers are sub-

galaxies.
Polarization Signatures of Kink Instabilities in the Blazar Emission Region from Relativistic Magnetohydrodynamic Simulations
Authors: Zhang Haocheng , Li Hui , Guo Fan , Taylor Greg
Published: January 2017

Kink instabilities are likely to occur in the current-carrying magnetized plasma jets. Recent observations of the blazar radiation and polarization signatures suggest that the blazar emission region may be considerably magnetized. While the kink instability has been studied with first-principle magnetohydrodynamic (MHD) simulations, the corresponding time-dependent radiation and polarization signatures have not been investigated. In this paper, we perform comprehensive polarization-dependent radiation modeling of the kink instability in the blazar emission region based on relativistic MHD (RMHD) simulations. We find that the kink instability may give rise to strong flares with polarization angle (PA) swings or weak flares with polarization fluctuations, depending on the initial magnetic topology and magnetization. These findings are consistent with observations. Compared with the shock model, the kink model generates polarization signatures that are in better agreement with the general polarization observations. Therefore, we suggest that kink instabilities may widely exist in the jet environment and provide an efficient way to convert the magnetic energy and produce multiwavelength flares and polarization variations.
Observations of the Formation, Development, and Structure of a Current Sheet in an Eruptive Solar Flare
Authors: Seaton Daniel B. , Bartz Allison E. , Darnel Jonathan M.
Published: January 2017

We present Atmospheric Imaging Assembly observations of a structure we interpret as a current sheet associated with an X4.9 flare and coronal mass ejection that occurred on 2014 February 25 in NOAA Active Region 11990. We characterize the properties of the current sheet, finding that the sheet remains on the order of a few thousand kilometers thick for much of the duration of the event and that its temperature generally ranged between 8 and 10 MK. We also note the presence of other phenomena believed to be associated with magnetic reconnection in current sheets, including supra-arcade downflows and shrinking loops. We estimate that the rate of reconnection during the event was M

A
 ≈ 0.004–0.007, a value consistent with model predictions. We conclude with a discussion of the implications of this event for reconnection-based eruption models.
L1188: A Promising Candidate for Cloud–Cloud Collisions Triggering the Formation of Low- and Intermediate-mass Stars
Authors: Gong Yan , Fang Min , Mao Ruiqing , Zhang Shaobo , Wang Yuan , Su Yang , Chen Xuepeng , Yang Ji , Wang Hongchi , Lu Dengrong
Published: January 2017

We present a new large-scale (2° × 2°) simultaneous 12CO, 13CO, and C18O (J = 1–0) mapping of L1188 with the Purple Mountain Observatory 13.7 m telescope. Our observations have revealed that L1188 consists of two nearly orthogonal filamentary molecular clouds at two clearly separated velocities. Toward the intersection showing large velocity spreads, we find several bridging features connecting the two clouds in velocity, and an open arc structure that exhibits high excitation temperatures, enhanced 12CO and 13CO emission, and broad 12CO line wings. This agrees with the scenario that the two clouds are colliding with each other. The distribution of young stellar object (YSO) candidates implies an enhancement of star formation in the intersection of the two clouds. We suggest that a cloud–cloud collision happened in L1188 about 1 Myr ago, possibly triggering the formation of low- and intermediate-mass YSOs in the intersection.
Particle-in-cell Simulations of Electron and Ion Dissipation by Whistler Turbulence: Variations with Electron β
Authors: Hughes R. Scott , Gary S. Peter , Wang Joseph
Published: January 2017

Two ensembles of three-dimensional particle-in-cell (PIC) simulations of the forward cascade of decaying whistler turbulence have been carried out on a model of collisionless, homogeneous, magnetized plasma with parameters similar to those of the solar wind near Earth. Initial, relatively isotropic, narrowband spectra of relatively long wavelength modes cascade to anisotropic, broadband spectra of magnetic fluctuations at shorter wavelengths. Electron and ion dissipation rates are computed as functions of the initial electron beta, β
e, over the range 0.1 ≤ β
e ≤ 5.0, where this quantity is varied by changes in the background magnetic field magnitude B
o. Ensemble One holds the value of the dimensionless initial magnetic fluctuation energy density ϵ
o ≡ Σk

constant; Ensemble Two follows solar wind observations, imposing the initial condition ϵ
o = 0.20 β
e. In both ensembles, the maximum dissipation rate of the electrons, Q
e, and the maximum dissipation rate of the ions, Q
i, satisfy Q
e ≫ Q
i. In Ensemble One, both dissipation rates scale approximately as

, whereas over 0.1 ≤ β
e ≤ 1.0 in Ensemble Two, Q
e is approximately constant while Q
i scales approximately as

. These results, when combined with conclusions from earlier PIC simulations, suggest that sufficiently long wavelength and sufficiently large-amplitude magnetosonic-whistler turbulence at sufficiently large β
e may heat ions more rapidly than electrons.
The Local Spiral Arm in the LAMOST-Gaia Common Stars?
Authors: Liu Chao , Wang You-Gang , Shen Juntai , Li Zhao-Yu , Qin Yu-Jing , Hou Yonghui , Wang Yuefei , Zhang Yong , Cao Zihuang , Wu Yue
Published: January 2017

Using the LAMOST-Gaia common stars, we demonstrate that the in-plane velocity fields for the nearby young stars are significantly different from those for the old ones. For the young stars, the probably perturbed velocities that are similar to the old population are mostly removed from the velocity maps in the X–Y plane. The residual velocity field shows that the young stars consistently move along Y with faster v

ϕ
at the trailing side of the local arm, while at the leading side, they move slower in the azimuth direction. At both sides, on average the young stars move inward with a v

R
of

km s−1. The divergence of the velocity in the Y direction implies that the young stars are associated with a density wave near the local arm. We therefore suggest that the young stars may reflect the formation of the local spiral arm by correlating themselves with a density wave. The range of the age for the young stars is around 2 Gyr, which is sensible since the transient spiral arm can persist for that long. We also point out that alternative explanations of the peculiar velocity field for the young population cannot be ruled out if solely using this observed data.
Computed Tomography–Guided Catheterization Drainage to Cure Spinal Tuberculosis With Individualized Chemotherapy
Authors: Li Jianhua , Huang Xuequan , Chen Feifan , Dai Fei , Zhou Qiang , Luo Fei , Xu Jianzhong , Zhang Zehua
Published: January 2017

The goal of this study was to investigate the effect of individualized chemotherapy delivered via percutaneous catheter drainage on paravertebral abscesses in spinal tuberculosis (TB). Data from 48 patients with spinal TB with paravertebral abscesses who received individualized chemotherapy via computed tomography–guided catheterization between 2009 and 2012 were retrospectively analyzed. The paravertebral abscesses affected the thoracic vertebra (n=12), the lumbar spine (n=20), the thoracolumbar vertebra (n=10), and the lumbosacral (n=6). All patients achieved clinical healing with no recurrence. Erythrocyte sedimentation rate and visual analog scale scores decreased significantly by the endpoint of follow-up. Although C-reactive protein values increased slightly right after treatment, they were also significantly lower at last follow-up. The kyphotic angle and Oswestry Disability Index values also exhibited significant decreases. No neurologic function impairment was reported. Computed tomography–guided catheterization for continuous administration of individualized chemotherapy was a safe and effective treatment for spinal TB with paravertebral abscesses in the cohort examined, and thus, it warrants further study. [
Orthopedics.
2017; 40(3):e443–e449.]
Portland blended cements: demolition ceramic waste management
Authors: Trezza M. A. , Zito S. , Tironi A. , Irassar E. F. , Rahhal V. F.
Published: January 2017

Demolition ceramic wastes (DCWs) were investigated in order to determine their potential use as supplementary cementitious materials in Portland Blended Cements (PBCs). For this purpose, three ceramic wastes were investigated. After characterization of the materials used, the effect of ceramic waste replacement (8, 24 and 40% by mass) was analyzed. Pozzolanic activity, hydration progress, workability and compressive strength were determined at 2, 7 and 28 days. The results showed that the ground wastes behave as filler at an early age, but as hydration progresses, the pozzolanic activity of ceramic waste contributes to the strength requirement.
UM ESTUDO SOBRE AS EVIDENCIAÇÕES CONTÁBEIS DOS GOVERNOS DO DISTRITO FEDERAL E DOS ESTADOS BRASILEIROS SOB A ÓTICA DA TEORIA DA LEGITIMIDADE E DOS CUSTOS POLÍTICOS
Authors: Araújo João Gabriel Nascimento de , Lagióia Umbelina Cravo Teixeira , Soeiro Tiago De Moura , Santos Aldemar De Araújo
Published: January 2017

Este estudo teve como objetivo investigar qual a aderência, sob a ótica da Teoria da Legitimidade e da hipótese de Custos Políticos, das evidenciações contábeis compulsórias e voluntárias que os Governos dos Estados brasileiros mais o Distrito Federal disponibilizam em seu sítio eletrônico. Com base na metodologia utilizada nos estudos de Beuren e Söthe (2009), Avelino et al. (2010), Araújo et al. (2014), e Araújo, Miranda e Lagióia (2015), foi uma pesquisa documental, qualitativa, com base na análise de conteúdo que buscou-se avaliar a evidenciação de informação compulsória estabelecida pela legislação; quais os tipos de evidenciações voluntárias divulgados; o nível de evidenciação voluntária e compulsória, conforme Hendriksen e Van Breda (1999), em adequada, justa e completa; categorizou-se os atributos das evidenciações tomando como critério para tal as características qualitativas da informação, contidas no Pronunciamento Conceitual Básico (R1). Concluiu-se que a maioria dos Governos Estaduais e do Distrito Federal não se sentem potencialmente ameaçados em sua legitimidade perante a sociedade, considerando o custo político do aumento dos níveis e qualidade das evidenciações frente à perda da legitimidade.
Quando se esforçar mais e não gastar mais faz toda a diferença: o caso da saúde pública em municípios do estado de São Paulo.
Authors: Teixeira Marco Antonio Carvalho , De Almeida Fernandes Gustavo Andrey , Leite Rafael Oliveira
Published: January 2017

O objetivo deste artigo é investigar a efetividade do atual modelo de financiamento de saúde pública no Brasil no nível municipal. Após uma introdução da evolução do Sistema Único de Saúde e do sistema contábil brasileiro, explorou-se como é realizado o gasto no setor. Em síntese, buscou-se avaliar se um aumento das despesas com saúde, mensurada com o índice de mortalidade infantil, bem como o esforço do gestor público, medido pela sua capacidade de ampliar a arrecadação, melhoram a qualidade da saúde pública. Os resultados apontam que o comprometimento do administrador público é importante, ainda que o aumento puro e simples do gasto não leve a um melhor desempenho.
Process Parameter Optimization for MRR and Surface Roughness during Machining LM6 Aluminum MMC on WEDM
Authors: Pujara Jay M. , Kothari Kartik D. , Gohil Ashish V.
Published: January 2017

WEDM process is newly emerged machining method in past decade which uses spark erosion method for the material removal while machining using high current. This method has shown high dimensional accuracy but gave rise to low machining rate. In current age of ultramodern technology a machine should satisfy more than one purpose. Therefore better Surface finish with dimensional accuracy for WEDM process has been very well presented in this paper with both the responses taken for study simultaneously. The paper deals with WEDM Process variables pulse ON/OFF time, peak current, servo voltage and wire feed rate. The paper also details about reduction of iterations for the desired output by using TLBO (Teaching-Learning Based Optimization) technique. The convergence graphs have been plotted in Minitab software to justify the reduction in iterations.
Public Financial Accountability: A pre-requisite to the management of Development Assistance in Mozambique beyond 2015
Authors: Makina Clive , Mago David
Published: January 2017

In Sub-Saharan Africa, Mozambique remains as one of the poorest countries in the region receiving large volumes of Development Assistance (DA) from the international donor community yet the majority of its population still continue to suffer from poverty. This article places much emphasis on efficient and effective Public Financial Management (PFM) as a key ingredient for the achievement of both the national and international development goals in Mozambique. Through a literature based study, the article acknowledges progress that has been recorded in the Millennium Development Goals. However, the paper considers the strengthening of PFM systems through enhanced accountability and transparency as essential elements in face of the recent global development commitment to the Sustainable Development Goals. A reviewof challenges experienced in the era of MDGs in the country points to a need for greater transparency and accountability in the management of DA if the country is to achieve the SDGs. Thus, arguing on the basis of the Agency theory, the article proposes the adoption of a stringent governance mechanism for Public Financial Management measures to shape government and donor financial accountability frameworks with the view of creating an enabling environment aimed at ensuring the achievement of Agenda 2025 and the 2030 Sustainable Development Goal (SDG) targets.
A generational perspective on work values in a South African sample
Authors: Jonck Petronella , Van der Walt Freda , Sobayeni Ntomzodwa C.
Published: January 2017

Orientation: In order to ensure harmonious relationships in the workplace, work values of different generational cohorts need to be investigated and understood.Research purpose: The purpose of this study was to investigate the work values of a South African sample from a generational perspective, in order to foster an understanding of the similarities and differences of different generational cohorts in terms of work values.Motivation of the study: Understanding the work values of different generational cohorts could assist organisations to manage and retain human capital in an increasingly competitive environment. Furthermore, it could assist organisations to develop an advanced understanding of employee behaviour, which should inform conflict-resolution strategies to deal with reported conflict between different generational cohorts.Research design, approach and method: The study was conducted within the positivist paradigm and was quantitative in nature. Data were gathered from 301 employees representing three different generational cohorts, namely the Baby Boomers, Generation X and Generation Y. A cross-sectional study was conducted, and data were collected once off by means of the Values Scale. The psychometric properties of the Values Scale have a reliability coefficient of 0.95, and the scale has been applied successfully in various iterations.Main findings: The findings indicate statistically significant differences and similarities between the various generational cohorts in terms of work values. More specifically, similarities and differences between the various generational cohorts were observed with regard to the values of authority, creativity, risk and social interaction in the work context.Practical/managerial implications: Organisations can use the findings of the study to strengthen employee interaction within the work environment. In addition, the findings can be used to inform retention and management strategies, in order to ensure harmonious relationships in the workplace.Contribution/value-add: The study contributes to the literature on South African generational cohorts and work values.
The changing role of continuity and discontinuity in the history of philosophy and mathematics
Authors: Strauss Danie F.M.
Published: January 2017

The aim of this article is to highlight the inevitability of employing discreteness and continuity as primitive (indefinable) modes of explanation in the history of philosophy and mathematics. It embodies the general challenge to account for the coherence of what is unique. Gödel emphasises the coherence of ‘primitive concepts’. Greek philosophy already discovered the spatial whole and/or parts relation with its infinite divisibility. During and after the medieval era philosophers toggled between an atomistic appreciation of the continuum and its opposite, for example found in the thought of Leibniz who postulated his law of continuity (lex continui). The discovery of incommensurability (irrational numbers) by the Greeks caused the first foundational crisis of mathematics, as well as its geometrisation. Leibniz and Newton did not resolve the problems surrounding the limit concept and soon it induced the third foundational crisis of mathematics. It caused Frege and the ‘continuum theoreticians’ to assign priority to the continuum – discreteness is a catastrophe. Recently Smooth Infinitesimal Analysis appreciated what is ‘continuous’ as constituting ‘an unbroken or uninterrupted whole’. Intuitionistic mathematics once more proceeded from an emphasis on the whole and/or parts relation. In spite of alternating attempts to understand continuity exclusively, either in arithmetical or in spatial terms, the history of philosophy and mathematics undeniably confirms that the co-conditioning role of these two modes of explanation remains a constant element in reflections on continuity and discontinuity. (The role of continuity and discontinuity within the disciplines of physics and biology will be discussed in a separate article.)
Psychophysiological analysis of Kriya Yoga as per Patanjala Yoga Sutra
Authors: Bapat Sarita Vivek
Published: January 2017

Background:

Kriya Yoga that includes Tapas,vadhyaya, and Ishwara pranidhana as given by Patanjala Yoga Sutra finds its mention twice in the text as Kriya Yoga and as Niyama. The double occurrence has significance.

Aim:

The aim of this work is to carry out an analysis of what Kriya Yoga is, what is the purpose of repeating three components of Kriya Yoga, i.e., Tapas,vadhyaya, and Ishwara pranidhana in Sadhana pada.

Method:

The three steps of Tapas,Svadhyaya, and Ishwara pranidhana were analyzed in detail. The important difference of this analysis from other commentators is to analyze the first two steps of Kriya Yoga from the psychophysiological point of view.

Analysis:

The Kriya Yoga brings psychophysiological changes leading to the total control of the body, i.e., internal functions of the body. It also leads to surrender to the internal supreme existence of one's own being. The process of Tapas, Svadhyaya, and Ishwara pranidhana, as per Kriya Yoga, converts a common person into a yogi.

Conclusion:

The process of Kriya Yoga facilitates the removal of resistance within i.e. preparing condition of chitta which is necessary for entering into Samadhi is fulfilled.
New light on Kliṣṭa and Akliṣṭa Vrttis
Authors: Mahadevan Jayaraman
Published: January 2017

Context:

Patañjali Yoga Sūtras classify Citta Vrttis into the Kliṣṭa and Akliṣṭa (Desikachar, 2014, p.16). After this initial mention, there are no further discussions on this 2-fold classification of the Vrttis in the text. Though Kleśas are discussed in the second chapter of text, the terms Kliṣṭa and Akliṣṭa themselves do not appear as part of discussion in the entire text after this initial mention. This gives rise to quite a few questions: What is the purpose of classifying the Vrttis into Kliṣṭa and Akliṣṭa? What is meant by Kliṣṭa and Akliṣṭa Vrttis? What is the nature of association of Kleśas with Vrttis? Should both Kliṣṭa and Akliṣṭa Vrttis be restrained or will it be enough if one focuses on restraining the Kliṣṭa Vrttis? and so on.

Aim:

Though the Sūtras themselves do not reveal any further information on this, many Sanskrit commentaries of Yoga Sūtra, beginning from the one ascribed to Vyāsa, address these questions. The aim is to study these commentaries to find answers to the questions raised above.

Method:

A descriptive method of analyzing arguments is used because of the philosophico-literary nature of the study.

Result:

The commentaries along with presenting various possible answers to the questions on the Kliṣṭa and Akliṣṭa Vrttis of the Yoga sūtras also reveal more relevant insights.

Conclusion:

On scrutiny of the commentaries, it becomes evident that all the techniques of Patañjali in the Yoga Sūtras, be it Abhyāsa vairagya, Kriyā Yoga, or Aṣṭāṅga Yoga, operate on the principles discussed under the Sūtra on Kliṣṭa and Akliṣṭa classification establishing Kliṣṭa and Akliṣṭa Vrttis as the foundational principles of Yoga Sūtras. The diverse yogic methods and techniques that are prescribed centered onthe body, breath, emotions, intellect, etc., seem to be aimed only at the generation of progressively varying levels of Akliṣṭa Vrttis and ultimately to overcome even these Akliṣṭa Vrttis to attain absolute Citta-vritti-nirodha.
Differential impact of Shavasana and meditation on memory scores in healthy college students
Authors: Bhogal Ranjeet Singh , Thakur Ghanshyam Singh , Shete Sanjay Uddhav
Published: January 2017

Background:

Yogic relaxation techniques endow its practitioners with the relaxation of Citta (i.e., mind, intellect, and ego) and freedom from psycho-physiological fatigue.

Objectives:

The purpose of the present study was to compare the differential impact of the guided instructions in Shavasana and meditation in supine posture on verbal, spatial, and associate memory scores.

Research Design:

This was a randomized controlled trial.

Method:

Randomly selected 45 healthy college students were equally divided into meditation group (n = 15), Shavasana group (n= 15), and control group (n = 15), with age range of 22–30 years. All individuals were assessed for total memory through Wechsler Memory Scale before and after the 30-day intervention of yoga, consisting of two types of relaxation techniques (Shavasana and meditation in supine posture). The sessions were of 30 min each for both the intervention groups for 6 days a week.

Results:

Results showed significant changes in memory scores among meditation and Shavasana groups as compared to the control group. Meditation group had shown a higher magnitude of change as compared to the other groups. Within-group comparison revealed significant changes in memory scores in both meditation (P < 0.001) as well as in Shavasana (P < 0.01) groups.

Conclusion:

This study has concluded that the guided relaxation techniques of yoga could bring a deeper relaxation at the psycho-physiological level which, in turn, could bring about a deeper impact at higher psychological levels resulting into significant improvement in verbal, spatial, and associate memory scores.
Effects of cloud condensation nuclei and ice nucleating particles on precipitation processes and supercooled liquid in mixed-phase orographic clouds
Authors: Fan Jiwen , Leung L. Ruby , Rosenfeld Daniel , DeMott Paul J.
Published: January 2017

Abstract. How orographic mixed-phase clouds respond to the change in cloud condensation nuclei (CCN) and ice nucleating particles (INPs) are highly uncertain. The main snow production mechanism in warm and cold mixed-phase orographic clouds (referred to as WMOCs and CMOCs, respectively, distinguished here as those having cloud tops warmer and colder than −20 °C) could be very different. We quantify the CCN and INP impacts on supercooled water content, cloud phases, and precipitation for a WMOC case and a CMOC case, with sensitivity tests using the same CCN and INP concentrations between the WMOC and CMOC cases. It was found that deposition plays a more important role than riming for forming snow in the CMOC case, while the role of riming is dominant in the WMOC case. As expected, adding CCN suppresses precipitation, especially in WMOCs and low INPs. However, this reverses strongly for CCN of 1000 cm−3 and larger. We found a new mechanism through which CCN can invigorate mixed-phase clouds over the Sierra Nevada and drastically intensify snow precipitation when CCN concentrations are high (1000 cm−3 or higher). In this situation, more widespread shallow clouds with a greater amount of cloud water form in the Central Valley and foothills west of the mountain range. The increased latent heat release associated with the formation of these clouds strengthens the local transport of moisture to the windward slope, invigorating mixed-phase clouds over the mountains, and thereby producing higher amounts of snow precipitation. Under all CCN conditions, increasing the INPs leads to decreased riming and mixed-phase fraction in the CMOC as a result of liquid-limited conditions, but has the opposite effects in the WMOC as a result of ice-limited conditions. However, precipitation in both cases is increased by increasing INPs due to an increase in deposition for the CMOC but enhanced riming and deposition in the WMOC. Increasing the INPs dramatically reduces supercooled water content and increases the cloud glaciation temperature, while increasing CCN has the opposite effect with much smaller significance.
Factors controlling black carbon distribution in the Arctic
Authors: Qi Ling , Li Qinbin , Li Yinrui , He Cenlin
Published: January 2017

Abstract. We investigate the sensitivity of black carbon (BC) in the Arctic, including BC concentration in snow (BCsnow, ng g−1) and surface air (BCair, ng m−3), as well as emissions, dry deposition, and wet scavenging using the global three-dimensional (3-D) chemical transport model (CTM) GEOS-Chem. We find that the model underestimates BCsnow in the Arctic by 40 % on average (median  =  11.8 ng g−1). Natural gas flaring substantially increases total BC emissions in the Arctic (by ∼ 70 %). The flaring emissions lead to up to 49 % increases (0.1–8.5 ng g−1) in Arctic BCsnow, dramatically improving model comparison with observations (50 % reduction in discrepancy) near flaring source regions (the western side of the extreme north of Russia). Ample observations suggest that BC dry deposition velocities over snow and ice in current CTMs (0.03 cm s−1 in the GEOS-Chem) are too small. We apply the resistance-in-series method to compute a dry deposition velocity (vd) that varies with local meteorological and surface conditions. The resulting velocity is significantly larger and varies by a factor of 8 in the Arctic (0.03–0.24 cm s−1), which increases the fraction of dry to total BC deposition (16 to 25 %) yet leaves the total BC deposition and BCsnow in the Arctic unchanged. This is largely explained by the offsetting higher dry and lower wet deposition fluxes. Additionally, we account for the effect of the Wegener–Bergeron–Findeisen (WBF) process in mixed-phase clouds, which releases BC particles from condensed phases (water drops and ice crystals) back to the interstitial air and thereby substantially reduces the scavenging efficiency of clouds for BC (by 43–76 % in the Arctic). The resulting BCsnow is up to 80 % higher, BC loading is considerably larger (from 0.25 to 0.43 mg m−2), and BC lifetime is markedly prolonged (from 9 to 16 days) in the Arctic. Overall, flaring emissions increase BCair in the Arctic (by ∼ 20 ng m−3), the updated vd more than halves BCair (by ∼ 20 ng m−3), and the WBF effect increases BCair by 25–70 % during winter and early spring. The resulting model simulation of BCsnow is substantially improved (within 10 % of the observations) and the discrepancies of BCair are much smaller during the snow season at Barrow, Alert, and Summit (from −67–−47 % to −46–3 %). Our results point toward an urgent need for better characterization of flaring emissions of BC (e.g., the emission factors, temporal, and spatial distribution), extensive measurements of both the dry deposition of BC over snow and ice, and the scavenging efficiency of BC in mixed-phase clouds. In addition, we find that the poorly constrained precipitation in the Arctic may introduce large uncertainties in estimating BCsnow. Doubling precipitation introduces a positive bias approximately as large as the overall effects of flaring emissions and the WBF effect; halving precipitation produces a similarly large negative bias.
Quantifying local-scale dust emission from the Arabian Red Sea coastal plain
Authors: Anisimov Anatolii , Tao Weichun , Stenchikov Georgiy , Kalenderski Stoitchko , Prakash P. Jish , Yang Zong-Liang , Shi Mingjie
Published: January 2017

Abstract. Dust plumes emitted from the narrow Arabian Red Sea coastal plain are often observed on satellite images and felt in local population centers. Despite its relatively small area, the coastal plain could be a significant dust source; however, its effect is not well quantified as it is not well approximated in global or even regional models. In addition, because of close proximity to the Red Sea, a significant amount of dust from the coastal areas could be deposited into the Red Sea and serve as a vital component of the nutrient balance of marine ecosystems.In the current study, we apply the offline Community Land Model version 4 (CLM4) to better quantify dust emission from the coastal plain during the period of 2009–2011. We verify the spatial and temporal variability in model results using independent weather station reports. We also compare the results with the MERRA Aerosol Reanalysis (MERRAero). We show that the best results are obtained with 1 km model spatial resolution and dust source function based on Meteosat Second Generation Spinning Enhanced Visible and InfraRed Imager (SEVIRI) measurements. We present the dust emission spatial pattern, as well as estimates of seasonal and diurnal variability in dust event frequency and intensity, and discuss the emission regime in the major dust generation hot spot areas. We demonstrate the contrasting seasonal dust cycles in the northern and southern parts of the coastal plain and discuss the physical mechanisms responsible for dust generation.This study provides the first estimates of the fine-scale spatial and temporal distribution of dust emissions from the Arabian Red Sea coastal plain constrained by MERRAero and short-term WRF-Chem simulations. The estimate of total dust emission from the coastal plain, tuned to fit emissions in MERRAero, is 7.5 ± 0.5 Mt a−1. Small interannual variability indicates that the study area is a stable dust source. The mineralogical composition analysis shows that the coastal plain generates around 76 ± 5 kt of iron oxides and 6 ± 0.4 kt of phosphorus annually. Over 65 % of dust is emitted from the northern part of the coastal plain.
Technical Note: Monte-Carlo genetic algorithm (MCGA) for model analysis of multiphase chemical kinetics to determine transport and reaction rate coefficients using multiple experimental data sets
Authors: Berkemeier Thomas , Ammann Markus , Krieger Ulrich K. , Peter Thomas , Spichtinger Peter , Pöschl Ulrich , Shiraiwa Manabu , Huisman Andrew J.
Published: January 2017

Abstract. We present a Monte-Carlo Genetic Algorithm (MCGA) for efficient, automated and unbiased global optimization of model input parameters by simultaneous fitting to multiple experimental data sets. The algorithm was developed to address the inverse modelling problems associated with fitting large sets of model input parameters encountered in state-of-the-art kinetic models for heterogeneous and multiphase atmospheric chemistry. The MCGA approach utilizes a sequence of optimization methods to find the solution of an optimization problem and to explore the space of solutions with similar model output. It addresses a problem inherent to complex models whose extensive input parameter sets might not be uniquely determined from limited input data. Such ambiguity in the derived parameter values can be reliably detected using this new set of tools. The MCGA algorithm has been used successfully to constrain parameters such as reaction rate coefficients, diffusion coefficients and Henry's law solubility coefficients in kinetic models of gas uptake and chemical transformation of aerosol particles as well as multiphase chemistry at the atmosphere-biosphere interface. It should be portable to any numerical model with similar computational expense and extent of the fitting parameter space.
Wind turbine impact on operational weather radar I/Q data: characterisation and filtering
Authors: Norin Lars
Published: January 2017

Abstract. For the past two decades wind turbines have been growing in number all over the world as a response to the increasing demand for renewable energy. However, the rapid expansion of wind turbines presents a problem for many radar systems, including weather radars. Wind turbines in line-of-sight of a weather radar can have a negative impact on the radar's measurements. As weather radars are important instruments for meteorological offices, finding a way for wind turbines and weather radars to co-exist would be of great societal value. Doppler weather radars base their measurements on in-phase and quadrature phase (I/Q) data. In this work a month worth of recordings of high resolution I/Q data from an operational Swedish C-band weather radar are presented. The impact of point targets, such as masts and wind turbines, on the I/Q data is analysed and characterised. It is shown that the impact of point targets on single radar pulses is manifested as a distinct and highly repeatable signature. The shape of this signature is found to be independent of the size, shape, and yaw angle of the wind turbine. It is further demonstrated how the robustness of the point target signature can be used to identify and filter out the impact of wind turbines in the radar's signal processor.
Sensor solutions for an energy-efficient and user-centered heating system
Authors: Hein Moritz , Stöber Ralf , Meiler Michael , Schaller Daniel , Zehle Rebecca , Fischerauer Gerhard , Bauer Jochen , Bürner Johannes , Franke Jörg , Becher Thomas , Feller Martin , Maul Joachim
Published: January 2017

Abstract. In contrast to conventional hydronic heating systems, in which the air is used as a medium for the convective heat transfer, an alternative approach is based on the usage of infrared (IR) radiant heating foils. These foils, which are applied to the walls and the ceiling of a laboratory, can be controlled individually. This leads to the possibility of heating the room zonewise and only when a person is present in a zone. A local comfortable climate is provided only in occupied zones, with the remaining zones being kept at a lower base temperature. Consequently, the measurement system has to detect persons in each zone and to determine the putative thermal comfort at relevant locations in the room. For the first problem, we examined and evaluated different sensor types capable of localizing persons without infringing on their anonymity. For the second problem, we used the fact that the thermal comfort mainly depends on the operative temperature (Li et al., 2010; DIN EN ISO 7730, 2006; de Dear and Brager, 2002). According to Simone et al. (2007), this temperature can be measured directly by an easily producible, planar sensor. The sensors were integrated in a wireless sensor network which consists of Wi-Fi-capable microcontroller boards, wireless smart home equipment, a Wi-Fi router, and a server.
Improvement of RAMS precipitation forecast at the short-range through lightning data assimilation
Authors: Federico Stefano , Petracca Marco , Panegrossi Giulia , Dietrich Stefano
Published: January 2017

Abstract. This study shows the application of a total lightning data assimilation technique to the RAMS (Regional Atmospheric Modeling System) forecast. The method, which can be used at high horizontal resolution, helps to initiate convection whenever flashes are observed by adding water vapour to the model grid column. The water vapour is added as a function of the flash rate, local temperature, and graupel mixing ratio. The methodology is set up to improve the short-term (3 h) precipitation forecast and can be used in real-time forecasting applications. However, results are also presented for the daily precipitation for comparison with other studies. The methodology is applied to 20 cases that occurred in fall 2012, which were characterized by widespread convection and lightning activity. For these cases a detailed dataset of hourly precipitation containing thousands of rain gauges over Italy, which is the target area of this study, is available through the HyMeX (HYdrological cycle in the Mediterranean Experiment) initiative. This dataset gives the unique opportunity to verify the precipitation forecast at the short range (3 h) and over a wide area (Italy). Results for the 27 October case study show how the methodology works and its positive impact on the 3 h precipitation forecast. In particular, the model represents better convection over the sea using the lightning data assimilation and, when convection is advected over the land, the precipitation forecast improves over the land. It is also shown that the precise location of convection by lightning data assimilation improves the precipitation forecast at fine scales (meso-β). The application of the methodology to 20 cases gives a statistically robust evaluation of the impact of the total lightning data assimilation on the model performance. Results show an improvement of all statistical scores, with the exception of the bias. The probability of detection (POD) increases by 3–5 % for the 3 h forecast and by more than 5 % for daily precipitation, depending on the precipitation threshold considered. Score differences between simulations with or without data assimilation are significant at 95 % level for most scores and thresholds considered, showing the positive and statistically robust impact of the lightning data assimilation on the precipitation forecast.
Numerical investigation of the Arctic ice–ocean boundary layer and implications for air–sea gas fluxes
Authors: Bigdeli Arash , Loose Brice , Nguyen An T. , Cole Sylvia T.
Published: January 2017

Abstract. In ice-covered regions it is challenging to determine constituent budgets – for heat and momentum, but also for biologically and climatically active gases like carbon dioxide and methane. The harsh environment and relative data scarcity make it difficult to characterize even the physical properties of the ocean surface. Here, we sought to evaluate if numerical model output helps us to better estimate the physical forcing that drives the air–sea gas exchange rate (k) in sea ice zones. We used the budget of radioactive 222Rn in the mixed layer to illustrate the effect that sea ice forcing has on gas budgets and air–sea gas exchange. Appropriate constraint of the 222Rn budget requires estimates of sea ice velocity, concentration, mixed-layer depth, and water velocities, as well as their evolution in time and space along the Lagrangian drift track of a mixed-layer water parcel. We used 36, 9 and 2 km horizontal resolution of regional Massachusetts Institute of Technology general circulation model (MITgcm) configuration with fine vertical spacing to evaluate the capability of the model to reproduce these parameters. We then compared the model results to existing field data including satellite, moorings and ice-tethered profilers. We found that mode sea ice coverage agrees with satellite-derived observation 88 to 98 % of the time when averaged over the Beaufort Gyre, and model sea ice speeds have 82 % correlation with observations. The model demonstrated the capacity to capture the broad trends in the mixed layer, although with a significant bias. Model water velocities showed only 29 % correlation with point-wise in situ data. This correlation remained low in all three model resolution simulations and we argued that is largely due to the quality of the input atmospheric forcing. Overall, we found that even the coarse-resolution model can make a modest contribution to gas exchange parameterization, by resolving the time variation of parameters that drive the 222Rn budget, including rate of mixed-layer change and sea ice forcings.