bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantum Path Interference and Multiple Electron Scattering in Soft X-Ray High-Order Harmonic Generation
Authors: Seres Jozsef , Seres Enikoe , Landgraf Bjoern , Aurand Bastian , Kuehl Thomas , Spielmann Christian
Published: January 2015

High-order harmonic generation is an important mechanism to generate coherent radiation in the few–100-eV spectral range with ultrashort laser pulses. Moreover, a closer inspection of the measured spectra provides unique information about the underlying physics and allows deriving guidelines for improvements. The long-range modulation of the spectral envelope is linked to phase matching, and we will show how to improve it with a double-pulse excitation scheme. Additionally, the spectrum contains only every fourth harmonic, which can be well explained by the quantum interference of multiple scattered electrons, and two dominant electron trajectories were selected by X-ray parametric interaction.
The Disappearance of Helike-Classical Greece—New Remote Sensing and Geological Evidence
Authors: Ferentinos George , Papatheodorou George , Geraga Maria , Christodoulou Dimitris , Fakiris Elias , Iatrou Margarita
Published: January 2015

Helike, the Achaean Dodecapolis capital, in the Corinth Gulf, Greece, was, according to historical sources, devastated and disappeared from sight during an earthquake followed by sea invasion on to land in 373/372 B.C. A marine remote sensing survey, which was carried out to examine a landslide following a 6.2 R earthquake in 1995, that affected the coastal and near-shore delta plain zone on which Helike stood, accompanied by onshore borehole data, enabled us to postulate the geological processes leading to the Helike catastrophe. Helike was initially leveled during a 6 to 6.7 R earthquake; it is postulated to have then submerged following a translational landslide caused by liquefaction. This Helike catastrophe model is consistent with historical sources and current views regarding the expected geological hazards magnitude in the Gulf.
Automatic Extraction of Optimal Endmembers from Airborne Hyperspectral Imagery Using Iterative Error Analysis (IEA) and Spectral Discrimination Measurements
Authors: Song Ahram , Chang Anjin , Choi Jaewan , Choi Seokkeun , Kim Yongil
Published: January 2015

Pure surface materials denoted by endmembers play an important role in hyperspectral processing in various fields. Many endmember extraction algorithms (EEAs) have been proposed to find appropriate endmember sets. Most studies involving the automatic extraction of appropriate endmembers without a priori information have focused on N-FINDR. Although there are many different versions of N-FINDR algorithms, computational complexity issues still remain and these algorithms cannot consider the case where spectrally mixed materials are extracted as final endmembers. A sequential endmember extraction-based algorithm may be more effective when the number of endmembers to be extracted is unknown. In this study, we propose a simple but accurate method to automatically determine the optimal endmembers using such a method. The proposed method consists of three steps for determining the proper number of endmembers and for removing endmembers that are repeated or contain mixed signatures using the Root Mean Square Error (RMSE) images obtained from Iterative Error Analysis (IEA) and spectral discrimination measurements. A synthetic hyperpsectral image and two different airborne images such as Airborne Imaging Spectrometer for Application (AISA) and Compact Airborne Spectrographic Imager (CASI) data were tested using the proposed method, and our experimental results indicate that the final endmember set contained all of the distinct signatures without redundant endmembers and errors from mixed materials.
Oxygen Control and Improved Denitrification Efficiency by Means of a Post-Anoxic Reactor
Authors: Urbini Giordano , Gavasci Renato , Viotti Paolo
Published: January 2015

The presence of dissolved oxygen (DO) in biological denitrification reactors determines inhibition effects on the denitrification rate. The article shows the results of an experimental study to control the DO concentration in the pre-denitrification stage by a post-anoxic reactor. The results demonstrate that the post-anoxic reactor is very effective in improving the nitrogen removal efficiency because it causes a considerable reduction of the DO content in the mixed liquor recycle sent to the pre-denitrification reactor. This reduction is influenced by both the retention time and the F:M ratio (referred to the denitrification and the oxidation-nitrification volume). In fact, a retention time and a F:M ratio equal to 1.5 h and 0.130 kgBOD5 kgMLVSS−1·day−1, respectively, allow to limit DO in the post-anoxic reactor at 0.31 mgO2·L−1. Such concentration determines a DO concentration of 0.11 mgO2·L−1 in the pre-denitrification reactor and, consequently, a denitrification efficiency of 91%. Moreover, the contribution of the endogenous denitrification to the whole denitrification efficiency was found negligible. The paper contributes to the progress in nitrogen removal from sewage, a fundamental issue for a sustainable management of water resources.
Solar Photovoltaic Development in Australia—A Life Cycle Sustainability Assessment Study
Authors: Yu Man , Halog Anthony
Published: January 2015

Australia possesses the highest average solar radiation of any continent in the world, but solar energy in total contributes less than 1% to Australia’s primary energy consumption. This study intends to assess whether solar photovoltaic (PV) is really a sustainable option for Australia’s energy transition on the project level. A life cycle sustainability assessment (LCSA) was conducted on a 1.2 MW flat-roof mounted PV solar array called UQ Solar, and the results suggested UQ Solar performed well in environmental aspects, except for emissions of several criteria air pollutants. It was economically feasible only with the grant provided by the Queensland government and the levelized cost of electricity (LCOE) was more or less the same as the LCOE of offset electricity. However, its social performance was not as good as expected. Large-scale PV installations can be sustainable in Australia on several conditions. PV manufacturers should be more responsible for reducing the use of hazardous materials; end-of-life treatment should be taken good care of; government should truly support the deployment of large-scale PV installation by providing more incentives and infrastructures; substantial subsidies for fossil fuel power stations should phase out; more awareness and training activities should be organized to promote social acceptance.
Development of a Comprehensive Fouling Model for a Rotating Membrane Bioreactor System Treating Wastewater
Authors: Paul Parneet , Anderson Jones Franck
Published: January 2015

Membrane bioreactors (MBRs) are now main stream wastewater treatment technologies. In recent times, novel pressure driven rotating membrane disc modules have been specially developed that induce high shear on the membrane surface, thereby reducing fouling. Previous research has produced dead-end filtration fouling model which combines all three classical mechanisms that was later used by another researcher as a starting point for a greatly refined model of a cross flow side-stream MBR that incorporated both hydrodynamics and soluble microbial products’ (SMP) effects. In this study, a comprehensive fouling model was created based on this earlier work that incorporated all three classical fouling mechanisms for a rotating MBR system. It was tested and validated for best fit using appropriate data sets. The initial model fit appeared good for all simulations, although it still needs to be calibrated using further appropriate data sets.
The Role of the Public Sector in Tourism Destination Management from a Network Relationship Approach
Authors: Van Niekerk Mathilda
Published: January 2015

The study aims to determine the suitability of the dyadic approach and the network relationship approach when engaging destination stakeholders and to identify the roles of the public sector within destination management. These study aims are investigated in the context of Mbombela Local Municipality, South Africa. A conceptual framework was developed based on a literature review. Data were then collected through official documents, 55 semistructured interviews with key stakeholders, a local economic summit, forum discussions, and 504 demand- and 403 supply-side questionnaires. The study findings suggest that the network relationship approach was the most suitable approach for the engagement of destination stakeholders. In addition to the roles identified in previous studies, the study findings identified several additional roles that the public sector should fulfill in destination management. Based on the study findings, a new conceptual framework for the role of the public sector in destination management has been proposed. By utilizing the conceptual framework developed in this study, destinations can engage their stakeholders more effectively and increase the attractiveness of their destinations. This is one of a few studies from Africa providing empirical findings on destination management and the role of the public sector within destination management.
The Impact of Tourism on Quality of Life: A Segmentation Analysis of the Youth Market
Authors: Eusébio Celeste , Carneiro Maria João
Published: January 2015

Despite the importance of the youth tourism market to the tourism industry, research on the impact of tourism on quality of life (QOL) of this market and on the factors that influence this impact is still very limited. This article contributes to overcoming the research gap in this
field, implementing a segmentation approach based on the impact of tourism on features related to several domains of youth tourists' QOL (physical health, psychological features, social relationships, and environment). This approach was empirically tested with a sample of university students.
The impact of tourism on youth tourists' QOL was assessed using an adapted version of the WHOQOL-BREF scale. The results reveal that tourism has an impact on the QOL of youth tourists and that this market is heterogeneous regarding the perceptions of this impact. Moreover, travel motivations,
host–tourist interactions, the travel group, and the type of destination visited seem to be the factors that have a higher influence on the perceptions of the impact of tourism on QOL. The article ends with some theoretical and practical contributions to the marketing and development
of tourism destinations.
Effects of Knowledge, Testimonials, and Ad Copy on Cruise Advertising Judgments
Authors: Martin Brett A. S. , Vincent Aaron
Published: January 2015

Tourist individual differences, such as levels of knowledge, are increasingly recognized as influencing how people respond to information. However, little research has examined the role of consumer knowledge on responses to different components of cruise advertising information. Using
input from an industry panel combined with insight and measures from the literature, the results of this field experiment show that consumer knowledge interacts with two aspects of advertising—testimonial expertise and advertising copy—to influence purchase intentions towards a
cruise. The results offer important implications for researchers and tourism managers regarding how consumer knowledge influences which types of advertising information are most persuasive to consumers. Results also indicate that expert consumers have more favorable attitudes than novice consumers
towards cruise advertising.
Is Tourism in Lebanon Subject to Permanent or Transitory Exogenous Shocks?
Authors: Bassil Charbel , Saleh Ali Salman , Anwar Sajid
Published: January 2015

The tourism industry makes a significant contribution to Lebanese gross domestic product (GDP). Lebanon has been rocked by political instability and regional conflicts over the past several decades. These exogenous shocks can adversely affect visitor arrivals. Using monthly data from 2008 to 2013, this article attempts to identify some statistically significant shocks to visitor arrivals to Lebanon and their nature (i.e., whether or not the impact of the shocks was temporary). The empirical analysis based on univariate as well as panel unit root testing procedures, where structural breaks are endogenously determined, suggests that at least one exogenous shock has significantly affected tourist arrivals to Lebanon. However, in overall terms, the impact of these shocks on visitor arrivals has been temporary.
Problem Gambling and Preventive Measures: The Case of Australia
Authors: Lee Timothy J. , Kim Hwa-Kyung
Published: January 2015

Problem gambling causes serious problems to personal well-being, families, communities, and even a country's economy. This article highlights the impacts of problem gambling and evaluates the current preventive measures taken by the federal and state governments and other organizations
in Australia. This article also presents recommendations to bolster the current preventive measures to reduce the widespread impacts of problem gambling. Exclusion programs, education about responsible gambling, involvement of the federal government, website filtering, direct mailing of responsible
gambling brochures, and automatic reminders in electronic gaming machines are recommendations devised to augment the current preventive measures in Australia in relation to problem gambling.
Taxonomic review ofManuleasubgenusSetema(Lepidoptera: Erebidae: Arctiinae: Lithosiini)
Authors: Dubatolov V.V.
Published: January 2015

The subgenusSetemade Freina and Witt of the genusManuleaWallengren (Lepidoptera: Erebidae: Arctiinae: Lithosiini) includes several Boreal and Arctic lichen-moth species: the EuropeanManulea(Setema)cereola(Hübner), the type species of the subgenus; the SiberianM.(S.)atratula(Eversmann),M.(S.)debilis(Staudinger), andM.(S.)vakulenkoi(Tshistjakov);M.(S.)hyalinofuscatum(Tshistjakov) from Chukotka;M. (S.)nigrocollare(Tshistjakov) from the Kolyma basin; and the North AmericanEilema bicolor(Grote) is also transferred into this subgenus asManulea(Setema)bicolor(Grote),new combination. A key to species is given.
A unique case of split cord malformation type 1 with three different types of bony spurs
Authors: Garg Kanwaljeet , Tandon Vivek , Mahapatra Ashok
Published: January 2015

Split cord malformation (SCM) is a rare congenital anomaly. The presence of bony spurs seen in type 1 SCM are usually partial and unequivocally are found attached to the dorsal surface of the vertebral body. We present here a unique case of SCM where the bony spur was found attached to the ventral aspect of the posterior arch and there were three different types of spurs (Type 1A, 1B and 1C) in the same patient.
Primary intracranial rhabdomyosarcoma of the cerebellopontine angle mimicking a vestibular schwannoma in a child
Authors: Nair Prakash , Das Kuntal , Srivastava Arun , Sahu R , Kumar Raj , Yadava Kamlesh , Pandey Rakesh
Published: January 2015

Primary intracranial rhabdomyosarcoma (PIRMS) is a rare neoplasm, which affects infants and young children. We report a rare case of a primary embryonal rhabdomyosarcoma of the cerebellopontine angle in a 7-year-old boy with clinical and radiological features mimicking a vestibular schwannoma. The patient underwent definitive surgery and radiotherapy and is recurrence free at 6 months. PIRMS commonly occur in parameningeal locations or metastasize to the brain from an extracranial primary. Gross total tumor resection followed by adjuvant radiotherapy remains the current standard of treatment; however, chemotherapy has also been tried with favorable results. The overall prognosis continues to remain poor.
Religion, postmodernism and postmodern scholarship in Africa
Authors: Adetolu JO
Published: January 2015

There is a somewhat agreement among the world academia and intellectuals that the world has moved beyond the stipulated margins of modernism into what is called the postmodern era. Consequently, postmodernism as a school of thought has become a subject of scholastic discourse among its protagonists and antagonists. What is done in this paper is an appraisal of postmodernism in a broader sense and specifically postmodern scholarship in the discipline of Religious Studies in Africa. The paper is divided into three sections: The first section examines the postmodernism project; the second focuses on the spirit of postmodernism within the academic study of religion with special interest in Africa, while the third section concludes the paper by examining some criticisms against postmodernism.Keywords: Postmodernism, Deconstruction, Post-structuralism, Decolonization and Modernism
Scientific progress and postmodern culture: the African experience
Authors: Negedu I
Published: January 2015

Scientific discourse grew out of various philosophical puzzles raised by human beings from the period of antiquity; and each age always comes with a renewed vigor for development over previous schools of thought with their attendant theories. With the speed of scientific progress and scientific awareness, there is no doubt that scholars from various disciplines fashion out theories to meet with the demands of the scientific spirit. It is this very presence of the scientific society that leads to contest for relevance among various theories/schools of thought. The African situation has been quite unique as the development of science is greeted with the idea that scientific developments have moral boundaries. Critically looking at development in science and how it has tailored our outlook in contemporary times, we opine that scientific investigations into phenomena make philosophical debates more relevant in our modern world.Keywords: Science, Scientific Progress, Post Modernity, Dialectic, Culture, African Experience.
Book Review: An amazing piece of comparative philosophy
Authors: Kimmerle H
Published: January 2015

Sophie Bosede Oluwole: Socrates and Orunmila. Two Patron Saints of Classical Philosophy.Lagos: Ark Publishers 2014, 224 p.Reviewer: Prof. Heinz KIMMERLEErasmus University RotterdamNetherlands, Emeritus
An experimental study on effect of process parameters in deep drawing using Taguchi technique
Authors: Reddy A. C. S. , Rajesham S. , Reddy P. R. , Kumar T. P. , Goverdhan J.
Published: January 2015

The effects of various deep drawing process parameters were determined by experimental study with the use of Taguchi fractional factorial design and analysis of variance for AA6111 Aluminum alloy. The optimum process parameters were determined based on their influence on the thickness variation at different regions of the blank material. Three important process parameters i.e., punch nose radius, die shoulder radius and blankholder force were investigated in this study. Plan of experiments based on Taguchi’s technique were used for acquiring the data. An orthogonal array, the signal to noise ratio and the analysis of variance were employed to investigate the deep drawability characteristics. Influence on thickness due to variation of these parameters was individually evaluated in terms of percentage. The results showed that the blankholder force (56.98%) was the most significant parameter followed by punch nose radius (30.12%) and the least influence (12.90%) was with die profile radius.Keywords: Axisymmetric deep drawing, Taguchi method, orthogonal array, S/N ratio, anova
A comparison of HONO budgets for two measurement heights at a field station within the boreal forest in Finland
Authors: Oswald R. , Ermel M. , Hens K. , Novelli A. , Ouwersloot H. G. , Paasonen P. , Petäjä T. , Sipilä M. , Keronen P. , Bäck J. , Königstedt R. , Hosaynali Beygi Z. , Fischer H. , Bohn B. , Kubistin D. , Harder H. , Martinez M. , Williams J. , Hoffmann T. , Trebs I. , Sörgel M.
Published: January 2015

Abstract. Atmospheric concentrations of nitrous acid (HONO), one of the major precursors of the hydroxyl radical (OH) in the troposphere, significantly exceed the values predicted by the assumption of a photostationary state (PSS) during daytime. Therefore, additional sources of HONO were intensively investigated in the last decades. This study presents budget calculations of HONO based on simultaneous measurements of all relevant species, including HONO and OH at two different measurement heights, i.e. 1 m above the ground and about 2 to 3 m above the canopy (24 m above the ground), conducted in a boreal forest environment. We observed mean HONO concentrations of about 6.5 × 108 molecules cm−3 (26 ppt) during daytime, more than 20 times higher than expected from the PSS of 0.2 × 108 molecules cm−3 (1 ppt). To close the budgets at both heights, a strong additional source term during daytime is required. This unidentified source is at its maximum at noon (up to 1.1 × 106 molecules cm−3 s−1, 160 ppt h−1) and in general up to 2.3 times stronger above the canopy than close to the ground. The insignificance of known gas phase reactions and other processes like dry deposition or advection compared to the photolytic decomposition of HONO at this measurement site was an ideal prerequisite to study possible correlations of this unknown term to proposed HONO sources. But neither the proposed emissions from soils nor the proposed photolysis of adsorbed HNO3 contributed substantially to the unknown source. However, the unknown source was found to be perfectly correlated to the unbalanced photolytic loss of HONO.
Temporal and spatial scaling impacts on extreme precipitation
Authors: Eggert B. , Berg P. , Haerter J. O. , Jacob D. , Moseley C.
Published: January 2015

Abstract. Both in the current climate and in the light of climate change, understanding of the causes and risk of precipitation extremes is essential for protection of human life and adequate design of infrastructure. Precipitation extreme events depend qualitatively on the temporal and spatial scales at which they are measured, in part due to the distinct types of rain formation processes that dominate extremes at different scales. To capture these differences, we first filter large datasets of high-resolution radar measurements over Germany (5 min temporally and 1 km spatially) using synoptic cloud observations, to distinguish convective and stratiform rain events. In a second step, for each precipitation type, the observed data are aggregated over a sequence of time intervals and spatial areas. The resulting matrix allows a detailed investigation of the resolutions at which convective or stratiform events are expected to contribute most to the extremes. We analyze where the statistics of the two types differ and discuss at which resolutions transitions occur between dominance of either of the two precipitation types. We characterize the scales at which the convective or stratiform events will dominate the statistics. For both types, we further develop a mapping between pairs of spatially and temporally aggregated statistics. The resulting curve is relevant when deciding on data resolutions where statistical information in space and time is balanced. Our study may hence also serve as a practical guide for modelers, and for planning the space–time layout of measurement campaigns. We also describe a mapping between different pairs of resolutions, possibly relevant when working with mismatched model and observational resolutions, such as in statistical bias correction.
Uncertainties in isoprene photochemistry and emissions: implications for the oxidative capacity of past and present atmospheres and for trends in climate forcing agents
Authors: Achakulwisut P. , Mickley L. J. , Murray L. T. , Tai A. P. K. , Kaplan J. O. , Alexander B.
Published: January 2015

Abstract. Current understanding of the factors controlling biogenic isoprene emissions and of the fate of isoprene oxidation products in the atmosphere has been evolving rapidly. We use a climate-biosphere-chemistry modeling framework to evaluate the sensitivity of estimates of the tropospheric oxidative capacity to uncertainties in isoprene emissions and photochemistry. Our work focuses on trends across two time horizons: from the Last Glacial Maximum (LGM, 21 000 years BP) to the preindustrial (1770s); and from the preindustrial to the present day (1990s). We find that different oxidants have different sensitivities to the uncertainties tested in this study, with OH being the most sensitive: changes in the global mean OH levels for the LGM-to-preindustrial transition range between −29 and +7%, and those for the preindustrial-to-present day transition range between −8 and +17%, across our simulations. Our results suggest that the observed glacial-interglacial variability in atmospheric methane concentrations is predominantly driven by changes in methane sources as opposed to changes in OH, the primary methane sink. However, the magnitudes of change are subject to uncertainties in the past isoprene global burdens, as are estimates of the change in the global burden of secondary organic aerosol (SOA) relative to the preindustrial. We show that the linear relationship between tropospheric mean OH and tropospheric mean ozone photolysis rates, water vapor, and total emissions of NOx and reactive carbon – first reported in Murray et al. (2014) – does not hold across all periods with the new isoprene photochemistry mechanism. Our results demonstrate that inadequacies in our understanding of present-day OH and its controlling factors must be addressed in order to improve model estimates of the oxidative capacity of past and present atmospheres.
LIVAS: a 3-D multi-wavelength aerosol/cloud climatology based on CALIPSO and EARLINET
Authors: Amiridis V. , Marinou E. , Tsekeri A. , Wandinger U. , Schwarz A. , Giannakaki E. , Mamouri R. , Kokkalis P. , Binietoglou I. , Solomos S. , Herekakis T. , Kazadzis S. , Gerasopoulos E. , Balis D. , Papayannis A. , Kontoes C. , Kourtidis K. , Papagiannopoulos N. , Mona L. , Pappalardo G. , Le Rille O. , Ansmann A.
Published: January 2015

Abstract. We present LIVAS, a 3-dimentional multi-wavelength global aerosol and cloud optical climatology, optimized to be used for future space-based lidar end-to-end simulations of realistic atmospheric scenarios as well as retrieval algorithm testing activities. LIVAS database provides averaged profiles of aerosol optical properties for the potential space-borne laser operating wavelengths of 355, 532, 1064, 1570 and 2050 nm and of cloud optical properties at the wavelength of 532 nm. The global climatology is based on CALIPSO observations at 532 and 1064 nm and on aerosol-type-dependent spectral conversion factors for backscatter and extinction, derived from EARLINET ground-based measurements for the UV and scattering calculations for the IR wavelengths, using a combination of input data from AERONET, suitable aerosol models and recent literature. The required spectral conversion factors are calculated for each of the CALIPSO aerosol types and are applied to CALIPSO extinction and backscatter data correspondingly to the aerosol type retrieved by the CALIPSO aerosol classification scheme. A cloud climatology based on CALIPSO measurements at 532 nm is also provided, neglecting wavelength conversion due to approximately neutral scattering behavior of clouds along the spectral range of LIVAS. Averages of particle linear depolarization ratio profiles at 532 nm are provided as well. Finally, vertical distributions for a set of selected scenes of specific atmospheric phenomena (e.g., dust outbreaks, volcanic eruptions, wild fires, polar stratospheric clouds) are analyzed and spectrally converted so as to be used as case studies for space-borne lidar performance assessments. The final global climatology includes 4-year (1 January 2008–31 December 2011) time-averaged CALIPSO data on a uniform grid of 1×1 degree with the original high vertical resolution of CALIPSO in order to ensure realistic simulations of the atmospheric variability in lidar end-to-end simulations.
Evolution of gaseous precursors and meteorological parameters during new particle formation events in the Central European boundary layer
Authors: Größ J. , Birmili W. , Hamed A. , Sonntag A. , Wiedensohler A. , Spindler G. , Maninnen H. E. , Nieminen T. , Kulmala M. , Hõrrak U. , Plass-Dülmer C.
Published: January 2015

Abstract. This paper revisits the atmospheric new particle formation (NPF) process in the polluted Central European troposphere, focusing on the diurnal evolution of the meteorological and gas phase parameters involved. Atmospheric aerosol observations include Neutral cluster and Air Ion Spectrometer (NAIS) measurements at the research station Melpitz, East Germany between 2008 and 2011. Particle formation events were classified by a new automated method based on the convolution integral of particle number concentration in the diameter range 2–20 nm. To study the relationship with gaseous precursors, a proximity measure was calculated for the sulfuric acid concentration on the basis of a one month intensive measurement campaign in May 2008. A major result was that the number concentration of fresh produced neutral particles correlated significantly with the amount of sulfur dioxide available as a main precursor of sulfuric acid. The condensation sink, a factor potentially inhibiting NPF events, played a subordinate role only. The same held for experimentally determined ammonia concentrations, which also represent a recognised precursor of aerosol particle nucleation. The analysis of meteorological parameters confirmed the absolute need for solar radiation to induce NPF events, and demonstrated the presence of significant turbulence during those events. Due to its tight correlation with solar radiation, however, an independent effect of turbulence for NPF could not be established with certainty. On the basis of observed diurnal cycles of aerosol, gas phase, and meteorological parameters near the ground, we conclude that particle formation is likely to be induced aloft, rather than near the ground.
Assessment of crop yield losses in Punjab and Haryana using two years of continuous in-situ ozone measurements
Authors: Sinha B. , Singh Sangwan K. , Maurya Y. , Kumar V. , Sarkar C. , Chandra B. P. , Sinha V.
Published: January 2015

Abstract. In this study we use a high quality dataset of in-situ ozone measurements at a suburban site called Mohali in the state of Punjab to estimate ozone related crop yield losses for wheat, rice, cotton and maize for Punjab and the neighbouring state Haryana for the years 2011–2013. We inter-compare crop yield loss estimates according to different exposure metrics such as AOT40 and M7 for the two major crop growing seasons of Kharif (June–October) and Rabi (November–April) and establish a new crop yield exposure relationship for South Asian wheat and rice cultivars. These are a factor of two more sensitive to ozone induced crop yield losses compared to their European and American counterparts. Relative yield losses based on the AOT40 metrics ranged from 27–41% for wheat, 21–26% for rice, 9–11% for maize and 47–58% for cotton. Crop production losses for wheat amounted to 20.8 million t in fiscal year 2012–2013 and 10.3 million t in fiscal year 2013–2014 for Punjab and Haryana jointly. Crop production losses for rice totalled 5.4 million t in fiscal year 2012–2013 and 3.2 million t year 2013–2014 for Punjab and Haryana jointly. The Indian National Food Security Ordinance entitles ~ 820 million of India's poor to purchase about 60 kg of rice/wheat per person annually at subsidized rates. The scheme requires 27.6 Mt of wheat and 33.6 Mt of rice per year. Mitigation of ozone related crop production losses in Punjab and Haryana alone could provide >50% of the wheat and ~10% of the rice required for the scheme. The total economic cost losses in Punjab and Haryana amounted to USD 6.5 billion in the fiscal year 2012–2013 and USD 3.7 billion in the fiscal year 2013–2014. This economic loss estimate represents a very conservative lower limit based on the minimum support price of the crop, which is lower than the actual production costs. The upper limit for ozone related crop yield losses in entire India currently amounts to 3.5–20% of India's GDP. Mitigation of high surface ozone would require relatively little investment in comparison to economic losses incurred presently. Therefore, ozone mitigation can yield massive benefits in terms of ensuring food security and boosting the economy. Co-benefits of ozone mitigation also include a decrease in the ozone related mortality, morbidity and a reduction of the ozone induced warming in the lower troposphere.
Characterisation and optimisation of a method for the detection and quantification of atmospherically relevant carbonyl compounds in aqueous medium
Authors: Rodigast M. , Mutzel A. , Iinuma Y. , Haferkorn S. , Herrmann H.
Published: January 2015

Abstract. Carbonyl compounds are ubiquitous in the atmosphere and either emitted primarily from anthropogenic and biogenic sources or they are produced secondarily from the oxidation of volatile organic compounds (VOC). Despite a number of studies about the quantification of carbonyl compounds a comprehensive description of optimised methods is scarce for the quantification of atmospherically relevant carbonyl compounds. Thus a method was systematically characterised and improved to quantify carbonyl compounds. Quantification with the present method can be carried out for each carbonyl compound sampled in the aqueous phase regardless of their source. The method optimisation was conducted for seven atmospherically relevant carbonyl compounds including acrolein, benzaldehyde, glyoxal, methyl glyoxal, methacrolein, methyl vinyl ketone and 2,3-butanedione. O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) was used as derivatisation reagent and the formed oximes were detected by gas chromatography/mass spectrometry (GC/MS). The main advantage of the improved method presented in this study is the low detection limit in the range of 0.01 and 0.17 μmol L−1 depending on carbonyl compounds. Furthermore best results were found for extraction with dichloromethane for 30 min followed by derivatisation with PFBHA for 24 h with 0.43 mg mL−1 PFBHA at a pH value of 3. The optimised method was evaluated in the present study by the OH radical initiated oxidation of 3-methylbutanone in the aqueous phase. Methyl glyoxal and 2,3-butanedione were found to be oxidation products in the samples with a yield of 2% for methyl glyoxal and 14% for 2,3-butanedione.
First on-line isotopic characterization of N2O emitted from intensively managed grassland
Authors: Wolf B. , Merbold L. , Decock C. , Tuzson B. , Harris E. , Six J. , Emmenegger L. , Mohn J.
Published: January 2015

Abstract. The analysis of the four main isotopic N2O species (14N14N16O, 14N15N16O, 15N14N16O, 14N14N18O) and especially the intramolecular distribution of 15N (site preference, SP) has been suggested as a tool to distinguish source processes and to help constrain the global N2O budget. However, current studies suffer from limited spatial and temporal resolution capabilities due to the combination of discrete flask sampling with subsequent laboratory-based mass spectrometric analysis. Quantum cascade laser absorption spectroscopy (QCLAS) allows selective high-precision analysis of N2O isotopic species at trace levels and is suitable for in situ measurements. Here, we present results from the first field campaign, conducted on an intensively managed grassland in central Switzerland. N2O mole fractions and isotopic composition were determined in the atmospheric surface layer (2 m height) at high temporal resolution with a modified state-of-the-art laser spectrometer connected to an automated N2O preconcentration unit. The analytical performance was determined from repeated measurements of a compressed air tank and resulted in measurement repeatability of 0.20, 0.12 and 0.11‰ for δ15Nα, δ15Nβ and δ18O, respectively. Simultaneous eddy-covariance N2O flux measurements were used to determine the flux-averaged isotopic signature of soil-emitted N2O. Our measurements indicate that in general, nitrifier-denitrification and denitrification were the prevalent sources of N2O during the campaign, and that variations in isotopic composition were rather due to alterations in the extent to which N2O was reduced to N2, than other pathways such as hydroxylamine oxidation. Management and rewetting events were characterized by low values of the intra-molecular 15N site preference (SP), δ15Nbulk and δ18O, suggesting nitrifier denitrification and incomplete heterotrophic bacterial denitrification responded most strongly to the induced disturbances. Flux-averaged isotopic composition of N2O from intensively managed grassland was 6.9 ± 4.3, -17.4 ± 6.2 and 27.4 ± 3.6‰ for SP, δ15Nbulk and δ18O, respectively. The approach presented here is capable of providing long-term datasets also for other N2O emitting ecosystems, which can be used to further constrain global N2O inventories.
Seasonality of sea ice controls interannual variability of summertime ΩA at the ice shelf in the Eastern Weddell Sea – an ocean acidification sensitivity study
Authors: Weeber A. , Swart S. , Monteiro P. M. S.
Published: January 2015

Abstract. Increasing anthropogenic CO2 is decreasing surface water aragonite saturation state (ΩA), a growing concern for calcifying Euthecosome pteropods and its wider impact on Antarctic ecosystems. However, our understanding of the seasonal cycle and interannual variability of this vulnerable ecosystem remains limited. This study examines surface water ΩA from four consecutive summers in the Eastern Weddell Gyre (EWG) ice shelf region, and investigates the drivers and the role played by the seasonal cycle in the interannual variability of ΩA. Interannual variability in the seasonal phasing and the rate of summer sea ice thaw was found to be the primary factor explaining interannual variability in surface water ΩA. In "optimal" summers when summer sea ice thaw began in late November/early December (2008/2009 and 2010/2011), the summertime increase in ΩA was found to be 1.02, approximately double that from summers when sea ice thaw was delayed to late December (2009/2010 and 2011/2012). We propose that the two critical climate (physical-biogeochemical) sensitivities for ΩA are the timing and the rate of sea ice thaw, which has a direct impact on the mixed layer and the resulting onset and persistence of phytoplankton blooms. The strength of summertime carbonate saturation depends on seasonal changes of sea ice, stratification and primary production. The sensitivity of surface water biogeochemistry in this region to interannual changes in mixed layer – sea ice processes, suggests that future trends in climate and the seasonal cycle of sea ice, combined with rapidly increasing anthropogenic CO2 will likely be a concern for the Antarctic ice shelf ecosystem within the next few decades. If in the future, primary production is reduced and CO2 increased, our results suggest that in the EWG summertime surface water aragonite undersaturation will emerge by the middle of this century.
Global warming increases the frequency of river floods in Europe
Authors: Alfieri L. , Burek P. , Feyen L. , Forzieri G.
Published: January 2015

Abstract. EURO-CORDEX, a new generation of downscaled climate projections, has become available for climate change impact studies in Europe. New opportunities arise in the investigation of potential effects of a warmer world on meteorological and hydrological extremes at regional scales. In this work, an ensemble of EURO-CORDEX RCP 8.5 scenarios is used to drive a distributed hydrological model and assess the projected changes in flood hazard in Europe through the current century. Changes in magnitude and frequency of extreme streamflow events are investigated by statistical distribution fitting and peak over threshold analysis. A consistent method is proposed to evaluate the agreement of ensemble projections. Results indicate that the change in frequency of discharge extremes is likely to have a larger impact on the overall flood hazard as compared to the change in their magnitude. On average in Europe, flood peaks with return period above 100 years are projected to double in frequency within three decades.
Inferring origin of mercury inclusions in quartz by multifractal analysis
Authors: Shibata T. , Maruoka T. , Echigo T.
Published: January 2015

Abstract. In order to refine our understanding of how fluid inclusions were trapped in the host minerals, we non-destructively observed mercury inclusions (liquid Hg0) in quartz samples using X-ray computed tomography (CT) technique. The X-ray CT apparatus can observe internal structures of the samples and give cross-sectional images from the transmission of the X-rays through the samples. From the cross-sectional images, we obtained three-dimensional spatial distributions of mercury inclusions, and quantitatively analyzed them using fractal and multifractal methods. Although the samples were from different geological settings, the resultant fractal dimensions were 1.70 and 1.71 for the San Benito and Itomuka samples, respectively. The fractal dimensions were also close to those predicted by diffusion-limited aggregation models and percolation theory, which are controlled by the irreversible kinetics. Given the fractal dimension and its implied mechanism, we conclude that the mercury-bearing fluids were not primary fluid inclusions, but migrated into the pre-existing cracks of quartz crystals by diffusion processes.
Discrete wavelet transform coupled with ANN for daily discharge forecasting into Três Marias reservoir
Authors: Santos C. A. G. , Freire P. K. M. M. , Silva G. B. L. , Silva R. M.
Published: January 2015

Abstract. This paper proposes the use of discrete wavelet transform (DWT) to remove the high-frequency components (details) of an original signal, because the noises generally present in time series (e.g. streamflow records) may influence the prediction quality. Cleaner signals could then be used as inputs to an artificial neural network (ANN) in order to improve the model performance of daily discharge forecasting. Wavelet analysis provides useful decompositions of original time series in high and low frequency components. The present application uses the Coiflet wavelets to decompose hydrological data, as there have been few reports in the literature. Finally, the proposed technique is tested using the inflow records to the Três Marias reservoir in São Francisco River basin, Brazil. This transformed signal is used as input for an ANN model to forecast inflows seven days ahead, and the error RMSE decreased by more than 50% (i.e. from 454.2828 to 200.0483).
River-bed erosion due to changing boundary conditions: performance of a protective measure
Authors: Termini D.
Published: January 2015

Abstract. Due to the introduction of man-made sediment barriers along a river, the amount of sediment load entering the downstream river reach is different to that leaving the reach, and erosion processes occur downstream of the barrier itself. Designers are often required to take into account the scouring process and to include adequate protective measures against the local scour. This paper addresses the performance of bio-engineering protective measures against the erosion process. In particular, a green carpet, realized with real flexible vegetation, has been used as the protective measure against erosion processes downstream of a rigid bed. Analyses are based on experimental work carried out in a straight channel constructed at the laboratory of the Dipartimento di Ingegneria Civile, Ambientale, Aereospaziale, dei Materiali, Palermo University (Italy).
Modelling approach for the rainfall erosivity index in sub-humid urban areas in northern Algeria
Authors: Touaibia I. , Abderrahmane Guenim N. , Touaibia B.
Published: January 2015

Abstract. This work presents an approach for storm water erosivity index modelling in the absence of measurement in an urban area, in a sub-humid climate. In torrential storms, floods, loaded with sediments, obstruct storm water drainage. With the aim of estimating the amount of sediment that can be deposited on a stretch of road, adjacent to the study area, the erosivity index is determined from a count of 744 rain showers recorded over a period of 19 years. The Universal Soil Loss Equation (USLE) of Wischmeier and Smith is applied, where only the index of erosivity is calculated; it is based on the intensity of the rain starting the process of erosion in the basin. Functional relations are required between this factor and the explanatory variables. A power type regression model is reached, making it possible to bring a decision-making aid in absences of measurements.
Parametric uncertainty or hydrological changes?
Authors: Viola F. , Noto L. V. , Pumo D.
Published: January 2015

Abstract. The model calibration is the way of hydrologists for searching also a physical interpretation of complex interactions acting within a basin. Actually, it can be frequently noticed how model calibration performed on a given time-window may converge to a point in the parameter space that could be distant from another obtainable calibration of the model in the same basin but considering a different time window. Is that again parametric uncertainty or does the trajectory in the parametric space relate about to a slow hydrological basin change? This paper depicts a possible path for detecting changes' signatures in a streamflow time series. In particular, the paper seeks to draw a way to discern the random variability over different time-windows of the calibrated model parameters set from that induced by the variation in time of some boundary conditions and external forcings. To this purpose, we will refer to a conceptual lumped model for simulating daily streamflow, the EHSM (EcoHydrological Streamflow Model), and to a hypothetical case study. The selected hydrological model requires a total of seven parameters, some of which can be easily related to land use, while others rely on climate variables. The calibration of the EHSM parameters with regard to different time-windows and the analysis of potential impacts of the anthropic variation in land use and/or climatic variability on the calibrated parameters set, will support our investigation.
Assessment of the intrinsic vulnerability of agricultural land to water and nitrogen losses: case studies in Italy and Greece
Authors: Aschonitis V. G. , Mastrocicco M. , Colombani N. , Salemi E. , Castaldelli G.
Published: January 2015

Abstract. LOS indices (abbr. of Losses) can be used for the assessment of the intrinsic vulnerability of agricultural land to water and nitrogen losses through percolation and runoff. The indices were applied on the lowland region of Ferrara Province (FP) in Italy and the upland region of Sarigkiol Basin (SB) in Greece. The most vulnerable zones in FP were the coastal areas consisting of high permeability sandy dunes and the areas close to riverbanks and palaeochannels, and in SB were the areas characterized by high slopes and high permeability soils at high altitude and areas belonging to the upper part of the alluvial plain close to the boundaries between agricultural land and mountainous regions. The application of LOS indices highlighted the specific features of both lowland and upland regions that contribute to water and nitrogen losses and showed their ability for use as tools in designing environmental management plans.