bluuebunny/crossref_metadata_2025 huggingface dataset:
Les sentiments de discrimination expliquent-ils les émeutes bruxelloises ?
Authors: Vandezande Véronique , Phalet Karen , Swyngedouw Marc
Published: January 2017

En septembre 2009 et au début de 2010, les problèmes de vie en commun se sont amplifiés dans certains quartiers de Bruxelles. Sont‑ils alimentés par des sentiments subjectifs de discrimination ? Nous étudions l’ampleur de la propagation des perceptions de discrimination chez les jeunes Belges d’origine turque et marocaine de la 2e génération, quels contextes de discrimination on distingue et dans quels groupes la discrimination est le plus ressentie. Par exemple, cette perception est‑elle limitée aux « jeunes à problèmes », ou ces expériences sont‑elles plus largement réparties au sein des groupes ? Pour matérialiser la situation dans la Région de Bruxelles-Capitale, nous effectuons une comparaison avec les mêmes sentiments des mêmes groupes à Anvers. Nous en concluons que la structure de la perception de la discrimination de groupe est similaire à Bruxelles et à Anvers pour les Belges de la 2e génération, tant d’origine marocaine que turque. Il n’y a aucune différence de niveau de la discrimination de groupe éprouvée. Seule celle qui est perçue dans l’espace public est plus forte à Anvers. Le niveau de celle qui est perçue dans les contacts avec la police ne diffère donc pas significativement entre les deux villes étudiées. Les confrontations avec la police occupent une place plus importante dans le concept latent à Bruxelles qu’à Anvers.
Do feelings of discrimination explain the riots in Brussels?
Authors: Vandezande Véronique , Phalet Karen , Swyngedouw Marc
Published: January 2017

Community problems escalated within certain Brussels neighbourhoods in September 2009 and at the beginning of 2010. Do subjective feelings of discrimination form a breeding ground for such events? We studied how widely spread the perceptions of discrimination are amongst young 2nd generation Belgians of Turkish and Moroccan origin, which contexts of discrimination are distinguished and who perceives the most discrimination. Is this perception indeed limited to so-called “problem youths”, or are such experiences more widely dispersed within the groups? In order to be able to contextualise the situation within the BCR, we compared the same feelings in the same groups within the city of Antwerp. We conclude that the structure of the perceived group discrimination is similar in Brussels and Antwerp for both the 2nd generation Belgians of Moroccan and Turkish origin. There is no difference in the level of experienced group discrimination. Only the perceived group discrimination within the public domain is higher in Antwerp. The level of perceived group discrimination in contacts with the police is thus not found to be significant in either city. However, confrontations with the police in Brussels do figure more strongly within the latent concept than in Antwerp.
Zijn de Brusselse gemeenten spilziek?
Authors: Verdonck Magali , Taymans Michèle , Van Droogenbroeck Nathalie
Published: January 2017

De Brusselse gemeenten worden vaak met de vinger gewezen, omdat ze hun financiën slecht zouden beheren en dringend hervormd zouden moeten worden. Dit artikel tracht de relatieve spilzicht van de Brusselse gemeenten te objectiveren aan de hand van een vergelijkende analyse van de financiën van de 19 Brusselse gemeenten met die van de gemeenten van de vier andere grote stedelijke clusters van België: Antwerpen, Charleroi, Gent en Luik. De gevolgde methode maakt het niet mogelijk te beweren dat de diensten van de Brusselse gemeenten niet efficiënter geleverd zouden kunnen worden. Ze maakt het daarentegen wel duidelijk dat als de Brusselse gemeenten spilziek zouden zijn, ze dat in ieder geval niet meer zijn dan de gemeenten van de andere stedelijke clusters, vooral als men ermee rekening houdt dat de andere gemeenten een deel van hun taken kunnen afschuiven op de provincies of op een groter aantal intercommunales. Uit de vergelijkende analyse blijkt dat er geen lokaal bevoegdheidsgebied is waar grote tekortkomingen worden vastgesteld, tenzij de sector Gezondheid en Hygiëne, die grondiger geanalyseerd moet worden. Daarentegen worden de bestuursproblemen waarmee de Brusselse gemeenten geconfronteerd worden, duidelijk naar voren gebracht.
Are the municipalities of Brussels guilty of wasteful spending?
Authors: Verdonck Magali , Taymans Michèle , Van Droogenbroeck Nathalie
Published: January 2017

The municipalities of Brussels are often accused of being a source of financial chaos and of requiring urgent reforms. The present article attempts to objectivise the question of relative wasteful spending by the municipalities of Brussels based on a comparison of the finances of the 19 municipalities of Brussels with those of the municipalities of the four other major urban entities in Belgium: Antwerp, Charleroi, Ghent and Liege.Our methodology does not allow us to affirm that the services of the municipalities of Brussels could not be provided more efficiently. It does, however, allow us to affirm that in the case of excessive spending by the municipalities of Brussels, it would not be more than that of the other entities studied, especially if we consider the fact that the other municipalities are able to hand over part of their competences to the provinces or to a higher number of intermunicipal companies.We were not able to identify a local sector of competence with significant shortcomings, apart from the health and hygiene sector which deserves a more in-depth analysis. On the contrary, the management constraints which the municipalities of Brussels are subjected to are what clearly emerged.
Het onderwijs in Brussel
Authors: Janssens Rudi , Carlier Donat , Van de Craen Piet
Published: January 2017

In deze bijdrage staat de situatie van het leerplichtonderwijs in het Brussels Hoofdstedelijk Gewest centraal. Scholen zijn geen geïsoleerde entiteiten waarbinnen het leerproces zich afspeelt maar kunnen niet los gezien worden van de grootstedelijke omgeving waarin ze functioneren. Om zicht te krijgen op dit complexe gegeven kunnen we de relatie tussen beide in vier aspecten samenvatten: de politiek-institutionele context (organisatie van het onderwijs), het pedagogisch-onderwijskundige proces (hoe en wat leren, in welke omstandigheden en met welk vooropgesteld resultaat), het demografisch-geografisch gegeven (bevolking waarvoor het onderwijs wordt georganiseerd), en de sociaal-culturele context (stedelijke ontwikkelingen) (Verlot, 2002). Alhoewel deze verschillende aspecten sterk met elkaar verweven zijn biedt deze indeling een interessante houvast om de concrete Brusselse situatie nader te bekijken en de vaststellingen en de probleemformulering nader te verduidelijken. Hierna volgen een aantal mogelijke politieke opties.Gezien de omvang van de problematiek wordt hier niet dieper ingegaan op het hoger onderwijs of beroepsopleiding. Deze aspecten komen in thema’s als “Brussel als kennisstad” en “de Brusselse arbeidsmarkt” aan bod.
Education in Brussels
Authors: Janssens Rudi , Carlier Donat , Van de Craen Piet
Published: January 2017

This paper focuses on the situation of compulsory education in the Brussels Capital Region. Schools are not isolated entities within which the learning process takes place and can not be viewed separately from the metropolitan environment within which they function. In order to gain an insight into this complex issue, the relationship between both can be summarised by four aspects: the political-institutional context (the organisation of education), the pedagogical-educational process (what is taught and how, in what circumstances and with which expected result), the demographic-geographic situation (the population for whom education is organised), and the social-cultural context (urban development) (Verlot, 2002). Although these different aspects are strongly interwoven, this division provides an interesting means by which the actual situation in Brussels is looked at more closely and by which the observations and the formulation of problems are made clearer. Finally, a number of political options are proposed.Due to the extent of the problems, the higher education and vocational education sectors are not examined here. They are addressed within topics such as “Brussels as a city of knowledge” and “The Brussels employment market”.
Brusselse jongeren: sociale ongelijkheid en culturele diversiteit
Authors: Rea Andrea , Nagels Carla , Christiaens Jenneke
Published: January 2017

Na de moord op Joe Van Holsbeeck is gebleken dat men de jongeren niet over dezelfde kam mag scheren: er zijn jongeren die goed presteren op school en opkomen voor een goede zaak; jongeren die automatisch verdacht worden en zomaar met de vinger worden gewezen; jongeren wier bestaan wordt onthuld door bewakingscamera’s. Rebellerende jongeren hebben twee ogenschijnlijk contradictorische eigenschappen: ze zijn grootmoedig, maar er gaat ook een dreiging van hen uit. De moord op Joe Van Holsbeek is meer dan een uiting van jongerengeweld. Men moet zich ook afvragen waarom men bepaalde Brusselse jongeren blijft uitsluiten, waarom hun bestaansonzekerheid toeneemt en waarom het antagonisme tussen jongeren van verschillende sociale en etnische afkomst toeneemt. Het hoofdstuk over jongeren in “Réussir Brussel”, opgesteld en uitgegeven door Charles Picqué in 1989, wijst op de geringe aandacht die men heeft voor deze bevolkingsgroep. Twintig jaar later gaat deze vaststelling nog steeds op. Erger nog, de situatie is in bepaalde opzichten verslechterd. Het Brussels Hoofdstedelijk Gewest telt een groot aantal jongeren. Dat is veeleer een bron van mogelijkheden en kansen dan een handicap. Echter, dat is niet de overheersende mening. Jongeren worden te vaak benaderd vanuit het perspectief van de sociale problemen die zij veroorzaken. Deze bijdrage ontsnapt, helaas, niet helemaal aan die trend.
Computational Methods for Prediction of Protein-Protein Interactions
Authors: Rai Sneha , Bhatnagar Sonika
Published: January 2017

The key signaling pathways in cellular processes involve protein-protein interactions (PPIs). A perturbation in the balance of PPIs occurs in various pathophysiological processes. There are a large numbers of experimental methods for detection of PPIs. However, experimental PPI determination is time consuming, expensive, error prone and does not effectively cover transient interactions. Therefore, overlaying and integration of predictive methods with experimental results provides statistical robustness and biological significance to the PPI data. In this chapter, the authors describe PPIs in terms of types, importance, and biological consequences. This chapter also provides a comprehensive description on various computational approaches for PPI prediction. Prediction of PPI can be done through: 1) Genomic information based methods 2) Structure based methods 3) Network topology based methods: 4) Literature and data mining based methods 5) Machine learning methods. For ease of use and convenience, a summary of various databases and software for PPI prediction has been provided.
Laser-Based Manufacturing Processes for Aerospace Applications
Authors: Stavropoulos Panos , Koutsomichalis Angelos , Vaxevanidis Nikos
Published: January 2017

In this chapter the latest developments in Laser manufacturing technologies and processes, used in the aerospace industry, are discussed. Current developments in the aerospace industry are characterised by the reduction of manufacturing and exploitation costs. Thus, the need for implementation of advanced manufacturing technologies and processes in the aeronautic industry, offering cost effective products with improved life cycle, is becoming more and more imperative. Lasers can be used in many industrial machining processes for a variety of materials including metals, ceramics, glass, plastics, and composites. Laser beams, used as machining tools, are not accompanied by problems such as tool wear, tool breakage, chatter, machine deflection and mechanically induced material damage, phenomena that are usually associated with traditional machining processes. The effectiveness of Lasers depends on the thermal nature of the machining process. Nevertheless, difficulties arise due to the difference in the thermal properties of the various components.
Chemiresistive Gas Sensors Based on Conducting Polymers
Authors: Pirsa Sajad
Published: January 2017

Chemiresistive gas sensor based on conducting polymer is a type of sensors that presents gas sensors with excellent characters; low-cost fabrication, fast detection, simultaneous determination (array gas sensor), portable devices and so. Theses gas sensors are commonly based on polyaniline (PANI), polypyrrole (PPy), polythiophene (PTh) and their derivatives as a transducer. Common configuration and response mechanism of these sensors are reported in this section. Some factors that induce selectivity to these sensors are discussed. Different materials (conductor or insulant) can be used as a substrate of polymerization. Type of substrate, selective membranes, surface modification of conducting polymer and so can change response behavior of these sensors.
Strengthening of Historic Masonry Structures with Composite Materials
Authors: Corradi Marco , Osofero Adelaja Israel , Borri Antonio , Castori Giulio
Published: January 2017

Existing un-reinforced masonry buildings made of vaults, columns and brick and multi-leaf stone masonry walls, many of which have historical and cultural importance, constitute a significant portion of construction heritage in Europe and rest of the world. Recent earthquakes in southern Europe have shown the vulnerability of un-reinforced masonry constructions due to masonry almost total lack of tensile resistance. Composite materials offer promising retrofitting possibilities for masonry buildings and present several well-known advantages over existing conventional techniques. The aim of this work is to analyze the effectiveness of seismic-upgrading methods both on un-damaged (preventive reinforcement) and damaged (repair) masonry building. After a brief description of mechanical and physical properties of composite materials, three different applications have been addressed: in-plane reinforcement of masonry walls, extrados and intrados reinforcement of masonry vaults/arches and masonry column confinement with composite materials.
Nanotechnology in Engineered Membranes
Authors: Choi Heechul , Son Moon , Bae Jiyeol , Choi Hyeon-gyu
Published: January 2017

The membrane processes have received extensive attention as comprehensive and interdisciplinary approaches for water-energy nexus. Nanotechnology has induced significant attention in improving membrane performances to mitigate global water and energy scarcity because of its unique characteristics and simple application for membrane fabrication. Nano-sized materials could provide highly enhanced characteristics to a membrane material, resulting in excellent performance enhancement, such as permeability, selectivity, and fouling resistance, of membrane. Carbon Nanotube (CNT), a widely utilized or studied nanomaterial in membrane science, is discussed in this chapter with a focus on its state-of-the-art applications and future prospects. Electrospun nanofiber, which is one of the feasible nano-structured membrane materials, is also discussed as a promising material for water-energy nexus. Therefore, this chapter also describes its application cases and its potential as an innovative membrane for water-energy nexus.
Practical Applications of X-Ray Line Profile Analysis
Authors: Gubicza Jenő
Published: January 2017

In the previous chapters, the theory and the main methods of diffraction peak profile analysis were presented. Additionally, the specialties in the measurement and the evaluation of line profiles in the cases of thin films and single crystals were discussed. In this chapter, some practical considerations are given in order to facilitate the evaluation of peak profiles and the interpretation of the results obtained by this method. For instance, the procedures for instrumental correction are overviewed. Additionally, how the prevailing dislocation slip systems and twin boundary types in hexagonal polycrystals can be determined from line profiles is shown. Besides the dislocation density, the vacancy concentration can also be obtained by the combination of electrical resistivity, calorimetric, and line profile measurements. The crystallite size and the twin boundary frequency determined by X-ray peak profile analysis are compared with the values obtained by the direct method of transmission electron microscopy. Furthermore, the limits of line profile analysis in the determination of crystallite size and defect densities are given. Finally, short overviews on the results obtained by peak profile analysis for metals, ceramics, and polymers are presented.
Nanotechnology in the Food Industry
Authors: Mir Shabir Ahmad , Shah Manzoor Ahmad
Published: January 2017

This chapter addresses the potential application of nanotechnology in various areas of the food industry. Nanotechnology is having an impact on several aspects of the food industry, from product development to packaging processes. Nanotechnology is capable of solving the very complex set of engineering and scientific challenges in the food processing industries. This chapter focuses on exploring the role of nanotechnology in enhancing food stability at the various stages of processing. Research has highlighted the prospective role of nanotechnology use in the food sector, including nanoencapsulation, nanopackaging, nanoemulsions, nanonutraceuticals, and nanoadditives. Industries are developing nanomaterials that will make a difference not only in the taste of food but also in food safety and the health benefits that food delivers. While proposed applications of nanotechnologies are wide and varied, developments are met with some caution as progress may be stifled by lack of governance and potential risks.
Assessment of Advanced Biological Solid Waste Treatment Technologies for Sustainability
Authors: Yasar Duygu , Celik Nurcin
Published: January 2017

53.8% of annually generated US Municipal Solid Waste was discarded in landfills by 2012. However, landfills fail to provide a sustainable solution to manage the waste. The State of Florida has responded to the need of establishing sustainable SWM systems by setting an ambitious 75% recycling goal to be achieved by 2020. To this end, Advanced Biological Treatment (ABT) and Thermal Treatment (ATT) of municipal solid waste premise a sustainable solution to manage the waste as it drastically reduces the volume of waste discarded in landfills and produces biogas that can be used to generate energy. In this chapter, ABT and ATT technologies are analyzed; and their advantages and disadvantages are examined from a sustainability perspective. A comprehensive top-to-bottom assessment of ABT technologies is provided for Florida using Analytic Hierarchy Process based on the collected subject matter expert rankings.
QSAR-Based Studies of Nanomaterials in the Environment
Authors: Kleandrova Valeria V. , Luan Feng , Speck-Planche Alejandro , Cordeiro M. Natália D. S.
Published: January 2017

Nanotechnology is a newly emerging field, posing substantial impacts on society, economy, and the environment. In recent years, the development of nanotechnology has led to the design and large-scale production of many new materials and devices with a vast range of applications. However, along with the benefits, the use of nanomaterials raises many questions and generates concerns due to the possible health-risks and environmental impacts. This chapter provides an overview of the Quantitative Structure-Activity Relationships (QSAR) studies performed so far towards predicting nanoparticles' environmental toxicity. Recent progresses on the application of these modeling studies are additionally pointed out. Special emphasis is given to the setup of a QSAR perturbation-based model for the assessment of ecotoxic effects of nanoparticles in diverse conditions. Finally, ongoing challenges that may lead to new and exciting directions for QSAR modeling are discussed.
Recent Trends and Advancement in Nanotechnology for Water and Wastewater Treatment
Authors: Banerjee Sushmita , Gautam Ravindra Kumar , Gautam Pavan Kumar , Jaiswal Amita , Chattopadhyaya Mahesh Chandra
Published: January 2017

Fast growing demand of fresh water due to increasing population and industrialization dictated research interests towards development of techniques that offers highly efficient and affordable methods of wastewater treatment. In recent decades water treatment using nano-technological based expertise have gained significant attention. Varieties of nanoparticles were synthesized and proficiently used in treatment of wide range of organic and inorganic contaminants from waste streams. This chapter encompasses recent development in nano-technological approach towards water and wastewater treatment. The authors tried to compile up to-date development, properties, application, and mechanisms of the nanoparticles used for decontamination purpose. This piece of work offer a well organized comprehensive assessment of the technology that delineates opportunities as well as its limitation in water management practices moreover few recommendations for future research are also proposed.
Metacognition and Metacognitive Skills
Authors: Valeyeva Nailya Sh. , Kupriyanov Roman , Valeyeva Elvira R.
Published: January 2017

The chapter incorporated the theoretical issues of metacognition, the correlation between metacognition and intellect, and the interconnection of metacognitive skills and intellectual development. A resolution is reached about the importance of purposeful development of students' intellectual skills. In order to develop students' intellectual skills in the educational process authors developed an Intellectual Skills Development Technology. The results of an empirical experiment are given proving the effectiveness of the offered technology in students' intellectual skills development. The study of connection the intellectual skills outlined in this chapter and the critical thinking is of major interest. Future research will be focused on determining the pedagogical methods of critical thinking development and assessing the effectiveness of these methods.
Learning at the Crossroads of Theory and Practice
Authors: Kumar Manoj
Published: January 2017

Current and emerging research on human learning provides a platform for the development of guiding principles of pedagogy aimed at improving student learning outcomes and the development of a life-long learning culture. This chapter will explore the implications of contemporary research on human learning for pedagogical practice. However what is clear for a high quality and future-oriented educational discourse, is the need, actively and continuously, to draw upon, synthesize and refine the rich array of insights available from this rapidly growing body of research. This chapter describes briefly the key learning theories often cited in educational research. These are grouped in broad categories according to their ideas of how learning occurs. Many of these theories are complementary, and can be applied equally to student learners and to teachers as learners. This chapter outlines various factors that researchers believe affect learning. Our developing knowledge of the human body, mind, emotions and social behaviors help us to understand better both learning and teaching.
Student's Psychological Factors and Metacognitive Skills in Higher Education
Authors: Moraru Adela
Published: January 2017

Metacognitive skills are a fundamental condition for the academic success of contemporary higher education students living in a knowledge-based society with abundant information, dynamic changes, and instant communication technologies. Although a student might have these skills in their repertoire, there are particular factors that might influence applying them during learning process, like: intrinsic motivation for the task, deeper processing learning strategies or having high executive control functions. The present chapter focuses on a few relevant psychological conditions of the student that might influence usage of metacognitive skills during learning in higher education. The author uses an interdisciplinary conceptual lens that brings together constructs from different theoretical perspectives in cognitive and educational psychology. A cross-sectional study was conducted to test the correlations and predictive power of the following constructs: learning strategies, motivation and executive functions on metacognitive skills, using a sample of 135 Romanian students.
Gossypibomas in India - A systematic literature review
Authors: Patial T , Thakur V , Vijhay Ganesun NK , Sharma M
Published: January 2017

Purpose of Review:

Gossypibomas remain a dreaded and unwanted complication of surgical practice. Despite significant interest and numerous guidelines, the number of reported cases remains sparse due to various factors, including potential legal implications. Herein, we review related data from India to ascertain if the problem is better or worse than that reported in world literature.

Materials and Methods:

A literature search was performed on PubMed and Google Scholar, to collect and analyze all case reports and case reviews regarding the condition in India.

Results:

On analysis of the results, there were 100 publications reporting a total of 126 events. The average patient age was 38.65 years. Average time to discovery was 1225.62 days. Forty-nine percent of reported cases were discovered within the 1st year. The most common clinical features were pain (73.8%), palpable mass (47.6%), vomiting (35%), abdominal distention (26%), and fever (12.6%). Spontaneous expulsion of the gossypiboma was noted in five cases (3.96%). Transmural migration was seen in 36 cases (28.57%).

Conclusions:

Despite advancements in surgical approaches and preventive measures, gossypibomas continue to be a cause of significant morbidity. A safe working culture, open communication, teamwork, and an accurate sponge count remain our best defence against this often unpredictable complication of surgery.
Hernia of the umbilical cord associated with a patent omphalomesenteric duct
Authors: Raicevic M , Filipovic I , Sindjic-Antunovic S
Published: January 2017

Congenital hernia of the cord is a different type of ventral abdominal wall defect in which the bowel usually herniates into the base of normally inserted umbilical cord through a patent umbilical ring. It is rare congenital anomaly with incidence of 1 in 5000. Although it was described as a distinct entity since 1920s it is often misdiagnosed as a small omphalocele. We present an unusal case of term male newborn with umbilical cord hernia associated with patent omphalomesenteric duct. The diagnose was made after birth despite antenatal ultrasound scans and it is managed successfully with uneventful recovery. If this is missdiagnosed, it could cause iatrogenic atresia of the ileum by clamping the umbilical cord after birth.
Существование двух нетривиальных решений в задачах на собственные значения для уравнений с разрывными правыми частями при достаточно больших значениях спектрального параметра
Authors: Pavlenko Vyacheslav Nikolaevich , Potapov Dmitriy Konstantinovich
Published: January 2017

В вещественном гильбертовом пространстве рассматривается вопрос существования решений задач на собственные значения для нелинейных уравнений с разрывными операторами. Вариационным методом получены теоремы о существовании двух нетривиальных решений при достаточно больших значениях спектрального параметра для исследуемых задач. В качестве приложения исследуются задачи на собственные значения для уравнений эллиптического типа с разрывными по фазовой переменной нелинейностями.
Библиография: 22 названия.
Асимптотика матрицы рассеяния вблизи краев спектральной лакуны
Authors: Nazarov Sergei Aleksandrovich
Published: January 2017

Изучено поведение матрицы рассеяния при приближении спектрального параметра к краю лакуны, изнутри или извне, в спектре квантового волновода, содержащего два рукава - цилиндрический и периодический. Прохождение спектрального параметра через лакуну в спектре приводит к перестройке матрицы рассеяния, так как количества волн внутри и вне лакуны различны. Тем не менее меньшая по размеру матрица рассеяния непрерывно трансформируется в идентичный блок большей матрицы рассеяния, которая к тому же в пределе на краю лакуны, т.е. на пороге спектра, становится блочно-диагональной. Неожиданные эффекты связаны именно с оставшимся блоком. Доказано, что предел этого блока на пороге может принимать только определенные значения, причем выбор того или иного значения определяется как строением непрерывного спектра, так и структурой подпространства "почти стоячих" волн на пороге - решений однородной задачи, не переносящих энергию на бесконечность. Критерий появления таких решений связывает размерность этого подпространства с кратностью собственного числа $-1$ пороговой матрицы рассеяния. Полученные асимптотические формулы, в частности, показывают, что эффект аномального рассеяния высокоамплитудных волн на околопороговых частотах, обнаруженный Л. А. Вайнштейном в частной акустической задаче, сохраняется и в периодических волноводах.
Библиография: 38 названий.
Diurnal variability of the atmospheric boundary layer height over a tropical station in the Indian monsoon region
Authors: Mehta Sanjay Kumar , Ratnam Madineni Venkat , Sunilkumar Sukumarapillai V. , Rao Daggumati Narayana , Krishna Murthy Boddapaty V.
Published: January 2017

Abstract. The diurnal variation of atmospheric boundary layer (ABL) height is studied using high-resolution radiosonde observations available at 3 h intervals for 3 days continuously from 34 intensive campaigns conducted during the period December 2010–March 2014 over a tropical station Gadanki (13.5° N, 79.2° E; 375 m), in the Indian monsoon region. The heights of the ABL during the different stages of its diurnal evolution, namely, the convective boundary layer (CBL), the stable boundary layer (SBL), and the residual layer (RL) are obtained to study the diurnal variabilities. A clear diurnal variation is observed in 9 campaigns out of the 34 campaigns. In 7 campaigns the SBL did not form in the entire day and in the remaining 18 campaigns the SBL formed intermittently. The SBL forms for 33–55 % of the time during nighttime and 9 and 25 % during the evening and morning hours, respectively. The mean SBL height is within 0.3 km above the surface which increases slightly just after midnight (02:00 IST) and remains almost constant until the morning. The mean CBL height is within 3.0 km above the surface, which generally increases from morning to evening. The mean RL height is within 2 km above the surface which generally decreases slowly as the night progresses. The diurnal variation of the ABL height over the Indian region is stronger during the pre-monsoon and weaker during winter season. The CBL is higher during the summer monsoon and lower during the winter season while the RL is higher during the winter season and lower during the summer season. During all the seasons, the ABL height peaks during the afternoon (∼ 14:00 IST) and remains elevated until evening (∼ 17:00 IST). The ABL suddenly collapses at 20:00 IST and increases slightly in the night. Interestingly, it is found that the low level clouds have an effect on the ABL height variability, but the deep convective clouds do not. The lifting condensation level (LCL) is generally found to occur below the ABL for the majority of the database and they are randomly related.
Uncertainties of ground-based microwave radiometer retrievals in zenith and off-zenith observations under snow conditions
Authors: Zhang Wengang , Xu Guirong , Liu Yuanyuan , Yan Guopao , Li Dejun , Wang Shengbo
Published: January 2017

Abstract. This paper is to investigate the uncertainties of microwave radiometer (MWR) retrievals in snow conditions and also explore the discrepancies of MWR retrievals in zenith and off-zenith observations. The MWR retrievals were averaged in a ±15 min period centered at sounding times of 00:00 and 12:00 UTC and compared with radiosonde observations (RAOBs). In general, the MWR retrievals have a better correlation with RAOB profiles in off-zenith observations than in zenith observations, and the biases (MWR observations minus RAOBs) and root mean square errors (RMSEs) between MWR and RAOB are also clearly reduced in off-zenith observations. The biases of temperature, relative humidity, and vapor density decrease from 4.6 K, 9 %, and 1.43 g m−3 in zenith observations to −0.6 K, −2 %, and 0.10 g m−3 in off-zenith observations, respectively. The discrepancies between MWR retrievals and RAOB profiles by altitude present the same situation. Cases studies show that the impact of snow on accuracies of MWR retrievals is more serious in heavy snowfall than in light snowfall, but off-zenith observation can mitigate the impact of snowfall. The MWR measurements become less accurate in snowfall mainly due to the retrieval algorithm, which does not consider the effect of snow, and the accumulated snow on the top of the radome increases the signal noise of MWR measurements. As the snowfall drops away by gravity on the sides of the radome, the off-zenith observations are more representative of the atmospheric conditions for RAOBs.
Elemental composition of ambient aerosols measured with high temporal resolution using an online XRF spectrometer
Authors: Furger Markus , Minguillón María Cruz , Yadav Varun , Slowik Jay G. , Hüglin Christoph , Fröhlich Roman , Petterson Krag , Baltensperger Urs , Prévôt André S. H.
Published: January 2017

Abstract. An Xact 625 ambient metals monitor was tested during a three-week field campaign at the rural, traffic-influenced site Härkingen in Switzerland during summer of 2015. The objective was to characterize the handling and operation of the instrument, evaluate the data quality by intercomparison with other independent measurements, and test its applicability for aerosol source quantification. The Xact was configured to measure 24 elements in PM10 with 1-h time resolution. Hourly element concentrations ranged from a few ng m−3 for trace elements in background conditions to tens of µg m−3 for major elements during a high-emission event (fireworks). The total Xact element mass comprised approximately 20 % of the total PM10 mass. The six major elements Si, S, Cl, K, Ca, and Fe contributed 95 % to the Xact PM10 mass, the remaining 5 % were attributed to the trace elements. Data quality was evaluated by intercomparison with 24-h PM10 filter data analysed with ICP-OES for major elements, ICP-MS for trace elements, and gold amalgamation atomic absorption spectrometry for Hg. 10 elements (S, K, Ca, Ti, Mn, Fe, Cu, Zn, Ba, Pb) showed an excellent correlation between the compared methods, with r2 values ≥ 0.95, even though the Xact 625 yielded approximately 28 % higher elemental concentrations than ICP for these elements. These elements demonstrate the high precision of the Xact instrument. An average 28 percent difference to ICP analyses might in part be attributed to the differences in the sampling systems (inlets), the geographic distance between the inlets and between the inlets and the freeway, and to uncertainties in the different analysis methods. 10 additional elements (Cr, V, Co, Ni, As, Se, Cd, Sn, Hg, Bi) could not be compared to a reference, because their concentrations were close to or below the minimum detection limits of at least one of the analysis methods. Sb revealed a calibration issue with the Xact, which requires correction. Si, Cl and Pt were not analysed with ICP, and thus could not be evaluated. The well-quantified elements were further used for a simple investigation of sources. The field campaign encompassed the Swiss National Day fireworks event, providing increased concentrations and unique chemical signatures compared to non-fireworks (or background) periods. Fireworks and traffic or rural background emissions could clearly be identified with their element mixture. The results demonstrate that multi-metal characterization at high-time resolution capability of Xact is a valuable and practical tool for ambient monitoring, exhibiting significant advantages compared to traditional elemental analysis methods.
Background CO2 levels and error analysis from ground-based solar absorption IR measurements in central Mexico
Authors: Baylon Jorge L. , Stremme Wolfgang , Grutter Michel , Hase Frank , Blumenstock Thomas
Published: January 2017

Abstract. In this investigation we analyze two common optical configurations to retrieve CO2 total column amounts from solar absorption infrared spectra. The noise errors using either a KBr or a CaF2 beamsplitter, a main component of a Fourier transform infrared (FTIR) spectrometer, are quantified in order to assess the relative precisions of the measurements. The configuration using a CaF2 beamsplitter, as deployed by the instruments which contribute to the Total Carbon Column Observing Network (TCCON), shows a slightly better precision. However, we show that the precisions in XCO2 retrieved from > 96 % of the spectra measured with a KBr beamsplitter, fall well below 0.2 %. A small bias in XCO2 (KBr – CaF2) of +0.56 ± 0.25 ppm was found when using an independent data set as reference. This value, which corresponds to +0.14 ± 0.064 %, is slightly larger than the mean precisions obtained and could be taken into account when homogenizing or comparing data from both beamsplitters. A 3-year XCO2 time series from FTIR measurements at the high-altitude site of Altzomoni in central Mexico presents clear annual and diurnal cycles and a trend of +2.2 ppm/yr could be determined.
An improved troposphere tomographic approach considering the signals coming from the side face of the tomographic area
Authors: Zhao Qingzhi , Yao Yibin
Published: January 2017

Abstract. The spatio-temporal distribution of atmospheric water vapour information plays a crucial role in the establishment of modern numerical weather forecast models and description of the different weather variations. A troposphere tomographic method has been proposed considering the signal rays penetrating from the side of the area of interest to solve the problem of the low utilisation rate of global navigation satellite system (GNSS) observations. Given the method above needs the establishment of a unit scale factor model using the radiosonde data at only one location in the research area, an improved approach is proposed by considering the reasonability of modelling data and the diversity of the modelling parameters for building a more accurate unit scale factor model. The new established model is established using grid point data derived from the European Centre for Medium-Range Weather Forecasts (ECMWF) and evenly distributed in the tomographic area, which can enhance the number of calculated initial water vapour density values with high accuracy. We validated the improved method with respect to the previous methods, as well as the result from a radiosonde using data from 12 stations from the Hong Kong Satellite Positioning Reference Station Network. The obtained result shows that the number of initial values estimated by the new model is increased by 6.83 %, while the internal and external accuracies are 0.08 and 0.24 g m−3, respectively. Integrated water vapour (IWV) and water vapour density profile comparisons show that the improved method is superior to previous studies in terms of RMS, MAE, and bias, which suggests higher accuracy and reliability.
Dissolved carbon biogeochemistry and export in mangrove-dominated rivers of the Florida Everglades
Authors: Ho David T. , Ferrón Sara , Engel Victor C. , Anderson William T. , Swart Peter K. , Price René M. , Barbero Leticia
Published: January 2017

Abstract. The Shark and Harney Rivers, located on the southwest coast of Florida, USA, originate in the freshwater, karstic marshes of the Everglades and flow through the largest contiguous mangrove forest in North America. In November 2010 and 2011, dissolved carbon source-sink dynamics were examined in these rivers during SF6 tracer release experiments. Approximately 80 % of the total dissolved carbon flux from all sources (i.e., freshwater wetlands, mangrove, carbonate dissolution, and marine input) out of the Shark and Harney Rivers during these experiments was as inorganic carbon, either via air-water CO2 exchange or longitudinal flux of inorganic carbon to the coastal ocean. Of the total mangrove-derived dissolved inorganic carbon (DIC) exported from the forests into these rivers, between 42 and 48 % was emitted to the atmosphere, with the remaining discharged to the coastal ocean. Dissolved organic carbon (DOC) represented ca. 10 % of the total mangrove-derived dissolved carbon export from the forests. The sum of mangrove-derived DIC and DOC export to these rivers was estimated to be at least 18.9 to 24.5 mmol m−2 d−1, a rate lower than other independent estimates from Shark River and from other mangrove forests. Results from these experiments also suggest that in this region, mangrove contribution to the estuarine flux of dissolved carbon to the ocean is less than 10 %.
The Plio-Pleistocene climatic evolution as a consequence of orbital
forcing on the carbon cycle
Authors: Paillard Didier
Published: January 2017

Abstract. Since the discovery of ice ages in the XIXth century, a central question of climate science has been to understand the respective role of the astronomical forcing and of greenhouse gases, in particular changes in the atmospheric concentration of carbon dioxide. Glacial-interglacial cycles have been shown to be paced by the astronomy with a dominant periodicity of 100 ka over the last million years, and a periodicity of 41 ka between roughly 1 and 3 million years before present (MyrBP). But the role and dynamics of the carbon cycle over the last 4 million years remain poorly understood. In particular, the transition into the Pleistocene about 2.8 MyrBP or the transition towards larger glaciations about 0.8 MyrBP (sometimes refered as the mid-pleistocene transition, or MPT) are not easily explained as direct consequences of the astronomical forcing. Some recent atmospheric CO2 reconstructions suggest slightly higher pCO2 levels before 1 MyrBP and a slow decrease over the last few million years (Bartoli et al., 2011; Seki et al., 2010). But the dynamics and the climatic role of the carbon cycle during the Plio-Pleistocene period remain unclear. Interestingly, the d13C marine records provide some critical information on the evolution of sources and sinks of carbon. In particular, a clear 400-kyr oscillation has been found at many different time periods and appears to be a robust feature of the carbon cycle throughout at least the last 100 Myr (eg. Paillard and Donnadieu, 2014). This oscillation is also visible over the last 4 Myr but its relationship with the eccentricity appears less obvious, with the occurrence of longer cycles at the end of the record, and a periodicity which therefore appears shifted towards 500-kyr (cf. Wang et al., 2004). In the following we present a simple dynamical model that provides an explanation for these carbon cycle variations, and how they relate to the climatic evolution over the last 4 Myr. It also gives an explanation for the lowest pCO2 values observed in the Antarctic ice core around 600–700 kyrBP. More generally, the model predicts a two-step decrease in pCO2 levels associated with the 2.4 Myr modulation of the eccentricity forcing. These two steps occur respectively at the Plio-Pleistocene transition and at the MPT, which strongly suggests that these transitions are astronomicaly forced through the dynamics of the carbon cycle.
Reconstructing long-term gully dynamics in Mediterranean agricultural areas
Authors: Hayas Antonio , Vanwalleghem Tom , Laguna Ana , Peña Adolfo , Giráldez Juan V.
Published: January 2017

Abstract. Gully erosion is an important erosive process in Mediterranean basins. However, the long-term dynamics of gully networks and the variations in sediment production in gullies are not well known. Available studies are often conducted only over a few years, while many gully networks form, grow, and change in response to environmental and land use or management changes over a long period. In order to clarify the effect of these changes, it is important to analyse the evolution of the gully network with a high temporal resolution. This study aims at analysing gully morphodynamics over a long timescale (1956–2013) in a large Mediterranean area in order to quantify gully erosion processes and their contribution to overall sediment dynamics. A gully network of 20 km2 located in southwestern Spain has been analysed using a sequence of 10 aerial photographs in the period 1956–2013. The extension of the gully network both increased and decreased in the study period. Gully drainage density varied between 1.93 km km−2 in 1956, a minimum of 1.37 km km−2 in 1980, and a maximum of 5.40 km km−2 in 2013. The main controlling factor of gully activity appeared to be rainfall. Land use changes were found to have only a secondary effect. A new Monte Carlo-based approach was proposed to reconstruct gully erosion rates from orthophotos. Gully erosion rates were found to be relatively stable between 1956 and 2009, with a mean value of 11.2 t ha−1 yr−1. In the period 2009–2011, characterized by severe winter rainfalls, this value increased significantly to 591 t ha−1 yr−1. These results show that gully erosion rates are highly variable and that a simple interpolation between the starting and ending dates greatly underestimates gully contribution during certain years, such as, for example, between 2009 and 2011. This illustrates the importance of the methodology applied using a high temporal resolution of orthophotos.
Improving the precipitation accumulation analysis using lightning measurements and different integration periods
Authors: Gregow Erik , Pessi Antti , Mäkelä Antti , Saltikoff Elena
Published: January 2017

Abstract. The focus of this article is to improve the precipitation accumulation analysis, with special focus on the intense precipitation events. Two main objectives are addressed: (i) the assimilation of lightning observations together with radar and gauge measurements, and (ii) the analysis of the impact of different integration periods in the radar–gauge correction method. The article is a continuation of previous work by Gregow et al. (2013) in the same research field. A new lightning data assimilation method has been implemented and validated within the Finnish Meteorological Institute – Local Analysis and Prediction System. Lightning data do improve the analysis when no radars are available, and even with radar data, lightning data have a positive impact on the results. The radar–gauge assimilation method is highly dependent on statistical relationships between radar and gauges, when performing the correction to the precipitation accumulation field. Here, we investigate the usage of different time integration intervals: 1, 6, 12, 24 h and 7 days. This will change the amount of data used and affect the statistical calculation of the radar–gauge relations. Verification shows that the real-time analysis using the 1 h integration time length gives the best results.
Aproximación teórica al diseño post-tecnicista
Authors: Ravanal G. Luis
Published: January 2017

Sin constituir un modelo ni hacer modificaciones fundamentales del espacio, la expresión Post-Tecnicista en la Arquitectura desarrolla una emblemática de la técnica que propone una tecnología-marketing para una arquitectura de corto plazo. Indagando en los signos visibles actuales de la continuidad de los procesos históricos asociados a la expresión del arte y la técnica en la arquitectura, se identifican los factores hegemónicos de dicha emblemática, señalando los fundamentos del diseño post-tecnicista.
Factores incidentes en la seguridad ciudadana en hábitat residenciales pobres, evaluación y propuesta
Authors: Sepúlveda O. Rubén
Published: January 2017

Se indaga en conjuntos residenciales pobres potencialidades y factores adversos a la seguridad ciudadana, para proponer un marco teórico y criterios técnicos apropiados, que orienten acciones y proyectos.