bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of graphene–transition metal oxide hybrid nanoparticles and their application in various fields
Authors: Jana Arpita , Scheer Elke , Polarz Sebastian
Published: March 2017

Single layer graphite, known as graphene, is an important material because of its unique two-dimensional structure, high conductivity, excellent electron mobility and high surface area. To explore the more prospective properties of graphene, graphene hybrids have been synthesised, where graphene has been integrated with other important nanoparticles (NPs). These graphene–NP hybrid structures are particularly interesting because after hybridisation they not only display the individual properties of graphene and the NPs, but also they exhibit further synergistic properties. Reduced graphene oxide (rGO), a graphene-like material, can be easily prepared by reduction of graphene oxide (GO) and therefore offers the possibility to fabricate a large variety of graphene–transition metal oxide (TMO) NP hybrids. These hybrid materials are promising alternatives to reduce the drawbacks of using only TMO NPs in various applications, such as anode materials in lithium ion batteries (LIBs), sensors, photocatalysts, removal of organic pollutants, etc. Recent studies have shown that a single graphene sheet (GS) has extraordinary electronic transport properties. One possible route to connecting those properties for application in electronics would be to prepare graphene-wrapped TMO NPs. In this critical review, we discuss the development of graphene–TMO hybrids with the detailed account of their synthesis. In addition, attention is given to the wide range of applications. This review covers the details of graphene–TMO hybrid materials and ends with a summary where an outlook on future perspectives to improve the properties of the hybrid materials in view of applications are outlined.
Derivatives of the triaminoguanidinium ion, 5. Acylation of triaminoguanidines leading to symmetrical tris(acylamino)guanidines and mesoionic 1,2,4-triazolium-3-aminides
Authors: Szabo Jan , Greiner Julian , Maas Gerhard
Published: March 2017

Depending on the reaction conditions, N,N’,N’’-tris(benzylamino)guanidinium salts can react with carboxylic acid chlorides to form either symmetrical N,N’,N’’-tris(N-acyl-N-benzylamido)guanidines 6 or mesoionic 4-amino-1,2,4-triazolium-3-hydrazinides 7. The latter were converted into 1,2,4-triazolium salts by protonation or methylation at the hydrazinide nitrogen atom. Neutral 1,2,4-triazoles 10 were obtained by catalytic hydrogenation of an N-benzyl derivative. Crystal structure analyses of a 4-benzylamino-1,2,4-triazolium-3-hydrazinide and of two derived 1,2,4-triazolium salts are presented.
THE EFFECT OF NITROGEN ON THE MICROBIOLOGICAL AND BIOCHEMICAL PROPERTIES OF ZINC-CONTAMINATED SOIL
Authors: STRACHEL Rafał , WYSZKOWSKA Jadwiga , BAĆMAGA Małgorzata
Published: March 2017

The aim of these studies was to determine the influence of excessive zinc doses on the microbiological and enzymatic properties of soil. Also, an evaluation of the possibility to stimulate remediation processes by nitrogen fertilisation of the soil was attempted. Zinc was applied to loamy sand in the amounts of 0, 250, 500, 750, 1000, 1250 mg Zn2+ kg–1 DM soil, while nitrogen in the form of urea in doses of 0, 250, 500 mg N kg–1 DM soil. Soil samples were incubated at a temperature of 25 °C, maintaining a constant humidity equal to 50% of the maximum water capacity. In the 2nd and 20th week of the experiment, the following factors were determined: activity of dehydrogenases and catalase, and number of organotrophic bacteria, copiotrophic bacteria, oligotrophic bacteria, actinomycetes, and fungi. Zinc inhibited the enzymatic activity of the soil, while causing a slight increase in populations of microorganisms. Only fungi reacted unequivocally positively to contamination of the soil with zinc, therefore demonstrating changes in the biodiversity of microorganisms. Nitrogen fertilisation of the soil resulted in stabilization of the environment contaminated with zinc by stimulation of growth of microorganisms resistant to the influence of this metal.
ASSESSMENT OF FUTURE URBAN GROWTH IMPACT ON LANDSCAPE PATTERN USING CELLULAR AUTOMATA MODEL: A CASE STUDY OF XUZHOU CITY, CHINA
Authors: LI Cheng , ZHAO Jie
Published: March 2017

Understanding and predicting of the urban growth process and its impact have become increasingly important for decision making toward sustainable development. In this paper, we presented a cellular automata model to assess the consequence of future urban growth. The hybrid calibration method combining logistic regression with trial-and-error was applied to estimate the parameters. The study proposed the integration method of Multi-Criteria Evaluation and Analytic Hierarchy Process that can be utilized to effectively translate the qualitative descriptions of scenarios into quantitative spatial analysis. Finally, the comparison of the different scenarios provided an insight into the impacts of different urban development strategies on landscape patterns. The result indicates that CA model can be effectively connected with the urban decision making processes. The moderate development scenario could be considered as the best one in achieving the objectives of compact urban form, good residential environment, as well as environmentally and economically efficient development.
EFFECTS OF URBAN GREEN BELTS ON THE AIR TEMPERATURE, HUMIDITY AND AIR QUALITY
Authors: ZHU Chunyang , JI Peng , LI Shuhua
Published: March 2017

As urbanization increases, designing green space that offers ecological benefits is an increasingly important goal of urban planning. As a linear green space in an urban environment, green belts lower air temperature, increase relative humidity, and improve air quality. To quantify the ecological effects of urban green belts and to identify a critical width for effective urban green belts, we analysed the width of urban green belts in terms of their effects on air temperature (T), relative humidity (RH), concentration of negative air ions (NAI) and bacteria rate (BR). The air T, RH and NAI from 8:00 to 18:00 and BR at 9:00 over seven days were investigated on six widths of green belts (0–10 m, 10–20 m, 20–30 m, 30–40 m, 40–50 m and over 50 m) along the west Fourth Ring Road of Beijing in April, July, October and December 2009. We found that (1) the T-RH benefits increased with the width of the green belts, and the 6 m belt had the smallest effect on T-RH, followed by the 16 m and 27 m belts, whereas the effect was obvious with the 34 m belt and conspicuous and stable with the 42 m belt (approximately 80% green coverage) (P < 0.05); (2) the critical width reference value of urban green belts for an obvious effect on the increase in NAI concentration was approximately 42 m (approximately 80% green coverage) (P < 0.05) and the NAI concentration increased with the width of green belts even in July; and (3) the positive effect on the decrease in the BR was greater than the negative effect, the BR decreased with the green belt width and the changes in the brs were stable with the 34 m belt. The results of this study may help urban planners and designers achieve urban green space designs that optimize ecological effects and cultural benefits.
Serum VEGF Levels in Helicobacter pylori Infection and Correlation with Helicobacter pylori cagA and vacA Genes
Authors: Siregar Gontar , Sari Dina , Sungkar Taufik
Published: March 2017

BACKGROUND: Helicobacter pylori vacA and cagA genes are associated with higher virulence. Vascular Endothelial Growth Factor (VEGF) is one important marker for neo-angiogenesis.AIM: The purpose of this study was to investigate the relationship between VEGF serum levels with cagA and vacA genes in H. pylori infection.METHODS: A cross-sectional study was done on eighty patients that consecutive admitted to endoscopy unit. The diagnosis of H. pylori infection was based on rapid urease test. Serum samples were obtained to determine circulating VEGF level. Polymerase chain reaction was done to examine H. pylori vacA and cagA genes. Data analysis were carried-out using SPSS version 22.Â RESULTS: A total of 80 patients were examined. There were 45 (56.3%) patients infected with Helicobacter pylori. There were 33 (73.3%) patients with H. pylori cagA positive. Serum VEGF levels in patients with the H. pylori positive were significantly higher compared to the patients that have no H. pylori. Serum levels of VEGF were significantly higher in cagA positive than negative.CONCLUSION: Serum VEGF level is correlated with H. pylori infection and its virulence status. The more virulence of H. pylori, cagA gene, the higher serum VEGF levels were found.
Follow Up of Value of the Intrarenal Resistivity Indices and Different Renal Biomarkers for Early Identification of Diabetic Nephropathy in Type 1 Diabetic Patients
Authors: Abd El Dayem Soha M. , El Bohy Abo El Magd , Hamed Mona , Ahmed Solaf
Published: March 2017

AIM: To evaluate intrarenal resistivity index (RI) and different biomarkers of diabetic nephropathy (DN) with clinical signs of DN and its progression over time as early detection of DN.PATIENTS AND METHODS: This longitudinal study included 48 type 1 diabetic patients who were studied at baseline and after three years. A blood sample was taken for assessment of glycosylated haemoglobin (HbA1), lipid profile and a urine sample was taken for assessment of albumin/creatinine ratio, Neutrophil gelatinase-associated lipocalin (NGAL), liver-type fatty acid binding protein (L-FABP) and kidney injury molecule-1 (Kim-1) at baseline and after three years. Forty diabetic patients did renal Doppler at baseline & after three years.RESULTS: HbA1, waist/hip ratio, albumin/creatinine ratio, lipid profile, NGAL, KIM-1, L-FABP and resistivity index (RI) were significantly increased in follow-up. Twenty patients (41.7%) showed progression to albuminuria. RI showed a significant increase in follow-up study. ROC curve showed that RI and NGAL had the highest sensitivity (100%), followed by L-FABP (90%) and lastly KIM-1 (63.6%) in the prediction of DN.CONCLUSION: High RI, NGAL, KIM-1 & L-FABP can be considered as early markers of diabetic nephropathy in type 1 diabetics and are associated with its progression over time, independent of albuminuria.
Expression of ERG Protein and TMRPSS2-ERG Fusion in Prostatic Carcinoma in Egyptian Patients
Authors: Abdel-Hady Ahmed , El-Hindawi Ali , Hammam Olfat , Khalil Heba , Diab Sara , Abd El-Aziz Soulafa , Badawy Mohamed , Ismail Ahmed , Helmy Noha , Kamel Nora , Anis Shady , El Kholy Amr , Al Osili Khalid , Abdel-Hady Afaf , Nour Hani , Akl Maha
Published: March 2017

AIM: Prostate cancer (PCa) is the second most common cancers in men worldwide. Its incidence can be influenced by several risk factors including genetic susceptibility. Therefore the search for the expression of a certain gene (ERG) and its rearrangement could give us clues for proper identification of PCa. And the study of ERG expression and its comparison to FISH in Egyptian patients can show whether ERG immunophenotype could be used instead of FISH, as it is cheaper.MATERIALS AND METHODS: This study was performed on 85 cases of PCa, showing 30 cases with HGPIN and 30 cases of prostatic hyperplasia. All were immunohistochemistry stained using ERG monoclonal rabbit antihuman antibody was used (clone: EP111). FISH analysis was performed in 38 biopsies of PCa cases to detect TMRPSS2-ERG rearrangement using the FISH ZytoLight TriCheck Probe (SPEC TMRPSS2-ERG).RESULTS: ERG expression was found in 26% of PCa cases and 20% of HGPIN cases. FISH analysis showed fusion of 21 cases of PCa (out of 22 cases showing ERG immunoexpression).CONCLUSION: Our findings emphasise that only malignant and pre-malignant cells and not benign cells from the prostate stain positive. ERG expression may offer a simpler, accurate and less costly alternative for evaluation of ERG fusion status in PCa.
Les conditions d’émergence et d’accélération des réseaux sociaux numériques d’entreprises : le cas du groupe d’assurances MMA
Authors: Montargot Nathalie , Duyck Jean-Yves
Published: March 2017

Les réseaux sociaux numériques d’entreprise permettent à des acteurs, le plus souvent dispersés géographiquement, de gagner en performance collaborative (Nonaka, 2007 ; Agterberg et al., 2010). Un réseau de ce type met au défi les hiérarchies existantes et un système de travail fondé sur la spécialisation des activités (Poinsot et al., 2010), en autorisant de nouvelles circulations d’ informations horizontales, transversales, ascendantes ou descendantes (Poncier, 2012). L’objet de ce travail consiste à voir dans quelle mesure ces réseaux contribuent à améliorer la f luidité des échanges et quels sont les éventuels freins limitant les usages collaboratifs. Dans un premier temps, une revue de littérature basée sur la théorie des réseaux et les spécificités des réseaux numériques de pratiques est présentée. Une étude de cas qualitative se concentre ensuite sur la globalité d’une expérimentation, portant sur le travail collaboratif, au sein du groupe d’assurances MMA, entre 2007 et 2014. Les résultats montrent que la structuration de la démarche s’est centrée autour de la viralité et du volontariat, dans une optique expérimentale et exploratoire. Si l’expérience a permis de faire émerger des communautés de travail et le partage de « bonnes pratiques », des résistances ont été constatées en interne. La discussion analytique et prescriptive permet de formuler des recommandations favorisant l’essor et le développement des réseaux sociaux numériques d’entreprise.
Callimachus and New Ancient Histories
Authors: Greene Robin J.
Published: March 2017

In this study I evaluate Callimachus’ rhetorical presentation and characterization of local historians and their material as either “old” or “new.” The first section focuses upon the Hecale. I show that Callimachus artificially antiquates and at the same time highlights the newness of previously unattested elements that he draws from the contemporary Attic histories of Philochorus and Amelesagoras I turn to the Aetia in the second section and concentrate on four examples of the poet’s representation of local historians and historical texts. By exaggerating the antiquity of the historian, Callimachus presents himself as a participant in an ancient historical tradition, while simultaneously emphasizing the modern qualities of his own “local history” of the Ptolemaic oikoumene.
“Harvesting from a New Page.” Philip of Thessalonike’s Editorial Undertaking
Authors: Höschele Regina
Published: March 2017

This paper explores the motif of novelty in Philip’s Garland and various aspects of its literary innovation vis-à-vis Meleager’s Stephanos through a close reading of Philip’s introductory poem (AP 4.2) and a series of epigrams starting with omega which are shown to have a programmatic function in marking the collection’s end.
Management de la qualité dans l’enseignement du français langue professionnelle : le cas d’une formation des infirmiers en milieu hospitalier.
Authors: Vemulapadu Ajey Balaji
Published: March 2017

Dans cette ère de mondialisation, la concurrence est ressentie partout et par tous. Afin de devancer la concurrence, les entreprises offrent des prestations « à valeur ajoutée », et, mettre en avant une équipe multilingue figure désormais parmi des prestations à valeur ajoutée. Face à la prolifération exponentielle du tourisme médical, une des nouvelles préoccupations des hôpitaux est de former leur personnel en langues étrangères (LE). Le cahier des charges joue traditionnellement le rôle de référentiel pour toute question sur le déroulement des formations. Force est de constater que ce document référentiel n’est que d’ordre énumératif et qu’il lui manque des éléments d’audit essentiels pour s’assurer de la qualité du service commandé et/ou proposé. Cette note pédagogique s’efforce d’explorer la possibilité d’emprunter les méthodes d’Ishikawa Kaouru et de « Quoi ? Qui ? Où ? Quand ? Comment ? Pourquoi ? » (QQOQQCP) pour repérer et analyser les causes des éléments variables d’une formation afin de sécuriser le processus pour les futures animations.
La discontinuité critique
Authors: Hubert Jean-Paul
Published: March 2017

Le monde est divers. La géographie cherche à comprendre cet état de fait. Dans cet effort, elle exprime la volonté de penser le monde habité d’une façon cohérente, de le penser comme étant organisé. Or, en avançant le concept d’organisation pour expliquer la diversité des paysages, la géographie introduit des a priori dans ses raisonnements. Elle présuppose que les lieux sont différents tout en étant solidaires, ce qui revient à dire que l’espace géographique doit être discontinu tout en étant unifié par des formes qui le structurent.

Comment identifier ces formes qui synthétisent l’organisation objective de l’écoumène? Parmi toutes les singularités qui différencient l’espace terrestre, lesquelles permettent de reconstituer la réalité de ces morphologies? S’agit-il de trames physiques tissées par la répartition des ressources de la nature, de découpages territoriaux qui en régissent l’accès? Ou s’agit-il de discontinuités plus fugaces, naissant par exemple de la rencontre fortuite d’une ombre portée et d’un obstacle dressé, de discontinuités qui font converger dans une communion esthétique l’attention des sujets, comme si leur était présentée l’idée d’un intérêt supérieur, transcendant leurs besoins personnels ?

Des théories s’opposent. L’auteur les appelle devant le tribunal de la Critique. Les candidats y exposeront leurs prétentions afin que soient jugées leurs capacités respectives à construire la représentation objective de l’organisation du monde et à atteindre l’explication théorique.
A Multi-Dimensional Mean Failure Cost Model to Enhance Security of Cloud Computing Systems
Authors: Jouini Mouna , Rabai Latifa Ben Arfa
Published: March 2017

Cloud computing technology is a relatively new concept of offering reliable and virtualized resources, software and hardware on demand to users. It presents a new technology to deliver computing resources as a service. It allows several benefits for example services on demand, provisioning, shared resources and pay per use and suffers from several challenges. In fact, security presents a major obstacle in cloud computing adoption. In this paper, the authors will deal with security problems in cloud computing systems and estimate security breaches using a quantitative security risk assessment model. Finally, the authors use this quantitative model to solve these problems in cloud environments.
Study on the Evolution of Defects in Helium-Implanted Tungsten
Authors: Wang Kang , Deng Ai Hong , Wang Ling , Wang Yong , Lu Xiao Bo , Gong Min
Published: March 2017

The microstructure of He+-irradiation induced defects in tungsten was studied as functions of annealing temperature by means of scanning electron microscope (SEM) and Doppler broadening positron annihilation spectroscopy (DB-PAS). The results show that the S parameter become higher after helium implanted in tungsten. When the annealing temperature increases to 923 K, plenty of large size of holes and new types of defects could be found in this sample.
Positron Manipulation and Positronium Laser Excitation in AEgIS
Authors: Mariazzi Sebastiano , Caravita Ruggero , Aghion Stefano , Amsler Claude , Ariga Akitaka , Ariga Tomoko , Bonomi Germano , Bräunig Philippe , Bremer Johan , Brusa Roberto S. , Cabaret Luis , Caccia Massimo , Castelli Fabrizio , Cerchiari G. , Chlouba Karl , Cialdi Simone , Comparat Daniel , Consolati Giovanni , Demetrio Andrea , di Noto Lea , Doser Michael , Dudarev Alexey , Ereditato Antonio , Evans Craig , Ferragut Rafael , Fesel Julian , Fontana Andrea , Forslund Ola K. , Gerber Sebastian , Giammarchi Marco , Gligorova Angela , Gninenko Sergei , Guatieri Francesco , Haider Stefan , Holmestad Helga , Huse Torkjell , Jernelv Ine L. , Jordan Elena , Kaltenbacher Thomas , Kellerbauer Alban , Kimura Mitsuhiro , Koetting Torsten , Krasnicky Daniel , Lagomarsino Vittorio , Lansonneur Pierre , Lebrun Patrice , Lehner Sebastian , Liberadzka Joanna , Malbrunot Chloe , Marx Lisa , Matveev Viktor , Mazzotta Zeudi , Nebbia Giancarlo , Nedelec Patrick , Oberthaler Markus , Pacifico Nicola , Pagano Davide , Penasa Luca , Petracek Vojtech , Pistillo Ciro , Prelz Francesco , Prevedelli Marco , Ravelli Luca , Resch Laura , Rienäcker Benjamin , Røhne Ole M. , Rosenberger Stefan , Rotondi Alberto , Sacerdoti Michele , Sandaker Heidi , Santoro Romualdo , Scampoli Paola , Sorrentino Fiodor , Spacek Michal , Storey James , Strojek Izabela M. , Testera Gemma , Tietje Ingmari , Vamosi Stefan , Widmann Eberhard , Yzombard Pauline , Zavatarelli Sandra , Zmeskal Johann
Published: March 2017

Production of antihydrogen by using the charge exchange reaction, as proposed by AEgIS (Antimatter Experiment: gravity, Interferometry, Spectroscopy), requires the formation of a dense cloud of positronium atoms excited to Rydberg states. In this work, the recent advances in AEgIS towards this result are described. Namely, the manipulation of positrons to produce bunches containing more than 108 particles and the laser excitation of positronium to Rydberg states, using n=3 as intermediate level, are presented.
Enegretics of the Ps Formation: Role of the Solvated Electron
Authors: Stepanov Sergey V. , Byakov Vsevolod , Zvezhinskiy Dmitry , Duplâtre Gilles
Published: March 2017

Taking liquid water as an example, we have considered energetics of the positronium formation. It is shown that quasi-free Ps as well as the Ps localized in a bubble cannot decay into hydrated electron and positron. The most probable value of the positron work function in water, V0+, is 1.5…2 eV. Ps formation from the hydrated electron and positron is energetically possible. By the end of thermalization major fraction of positrons escapes the blob and hydrates outside. The low-mobile е+aq has no time to diffuse back and form Ps with intrablob e-. These е+aq mostly annihilate as “free positrons”. Positrons, which are thermalized within the blob, recombine with the quasi-free intrablob electrons and form Ps.
Study of Defects in High Energy Ion Implanted ZnO Crystals
Authors: Melikhova Oksana , Čížek Jakub , Procházka Ivan , Hruška Petr , Anwand Wolfgang , Havránek Vladimír , Skuratov Vladimir A. , Strukova Tatiana S.
Published: March 2017

Positron annihilation spectroscopy (PAS) was employed for characterization of defects in the hydrothermally (HT) grown zinc oxide single crystals irradiated by high energy ions. Defects created in ZnO crystals by 2.5 MeV protons, 7.5 MeV N3+ and 167 MeV Xe26+ ions were compared. The virgin ZnO crystals contain Zn-vacancies associated with hydrogen. Ion implantation introduced additional defects, namely Zn+O di-vacancies in crystals irradiated by protons and small vacancy clusters in samples implanted by N and Xe ions.
Effect of La Doping on the Microstucture and Nonlinear Characteristics of CaCu3Ti4O12  Ceramics
Authors: Chen Jing , Li Tao , Dai Hai Yang , Chen Zhen Ping
Published: March 2017

Ca1-xLaxCu3Ti4O12 (x=0-0.05) ceramics are prepared by the solid-state reaction method. The effects of La doping on the microstructure and non-Ohmic properties of Ca1-xLaxCu3Ti4O12 system are investigated by XRD, SEM and Positron annihilation technique. The results show that no phase transition occurs in the doping range (x=0-0.05), while the significant changes in grain size can be observed as x≥0.02. The positron lifetime results prove that the average lifetime is strongly affected by La doping. The correlation of the nonlinear behavior of CaCu3Ti4O12 system and the grain size, the local electron density in defect was discussed.
Positron Annihilation Study of Porous ZnO Synthesized with Soft Template
Authors: Zhou Bo , Li Chong Yang , Qi Ning , Chen Zhi Quan
Published: March 2017

Porous ZnO were synthesized with soft template method using zinc acetate Zn (CH3COO)2·2H2O as precursor and block copolymer F127 as the surfactant. Nitrogen adsorption-desorption measurements indicate that the ZnO sample contains large pores with mean diameter of about 30 nm. However, both small-angle X-ray diffraction and transmission electron microscope measurements indicate that the pore ordering is missing. Positron lifetime measurements reveal two long lifetime components in the porous ZnO. The longest lifetime τ4 (75 ns) corresponds to ortho-positronium (o-Ps) annihilation in large pores. The pore size estimated from τ4 is about 10.6 nm. This is much smaller than that estimated from Nitrogen adsorption-desorption measurements. In addition, the intensity I4 is only about 2.2%. This is probably due to the chemical quenching and/or inhibition of positronium formation induced by ZnO, which reduces o-Ps lifetime and intensity, and leads to under estimation of the pore size.
Application and Evaluation of 3D Printed Materials with PALS
Authors: Paul Matthew D. , Davis Jonathan S. , Jean Yan Ching , van Horn J. David
Published: March 2017

In this study, the use of a 3D printer for sample holder fabrication and polymer sample preparation for positron analysis was explored. Custom printed 3D holders may be rapidly made and modified for a variety of thin-film, crystalline, or other diversely-shaped samples. For positron studies a 3D printer allows for the preparation of standard and unique polymer samples. In an initial study, a mesoporous-patterned ABS sample was attempted, without success. Various polymers (ABS, PLA, and PETG) and the same polymers with varied additives (carbon fiber or carbon nanotubes) were studied before and after printing. The different polymers and those with additives are distinguishable via PALS. Samples show a consistently lower I3 value after printing, suggesting a decrease in defect quantity for the printed polymer versus the as-received polymer filament.
Observation of a Low Energy Component of Positronium Emitted from Alkali-Metal Coated Polycrystalline Tungsten Surfaces
Authors: Iida Shimpei , Terabe Hiroki , Tachibana Takayuki , Wada Ken , Mochizuki Izumi , Yagishita Akira , Hyodo Toshio , Nagashima Yasuyuki
Published: March 2017

We have studied the emission of ortho-positronium from alkali-metal coated polycrystalline tungsten surfaces. The positronium time-of-flight spectra show that the yield of the 5 eV positronium component increases by alkali-metal coating. In addition, a low energy positronium component appears by Cs or K coating. We suggest that this component is due to positron energy loss by inter-band transition or surface plasmon excitation.
Simulation Study of Positron Beam Generation via Irradiating an Ultra-Intense Laser on a Hollow Target
Authors: Liu Jian Xun , Ma Yan Yun , Zhao Jun , Yu Tong Pu , Yang Xiao Hu , Wang Wei Quan , Jiang Jing
Published: March 2017

By simulation with the relativistic PIC code EPOCH, it is found that a hollow target ismore beneficial than a plane one for the collimation and compression of the positrons. Irradiating anultra-intense laser (4×1023 W/cm2) on a hollow target, 8.74×1015 positrons are generated. Due tothe focusing effect of the transverse electric field formed in the hollow wall, the divergence angle isaround 21° , while the maximum density of the beam is 4.77×1021 cm-3. When the laser intensity is doubled, both the yield (5.31 ×1016) and the maximum density (1.57 ×1022 cm-3) are greatly increased while the beam divergence gets even smaller (15.7 °).
Ionic Liquid Loaded Silica Gel Particles Studied by Spatially Resolved DBS Using a Scanning Positron Beam
Authors: Reiner Markus , Ceeh Hubert , Gigl Thomas , Haumann Marco , Schönweiz Andreas , Hugenschmidt Christoph
Published: March 2017

The CDB-spectrometer at NEPOMUC enables spatially resolved Doppler Broadening Spectroscopy of the electron-positron annihilation line with a lateral resolution of up to 200~$\mu$m (FWHM). We have applied this technique for studying single particles of silica gel dependent on loading with an altering amount of the ionic liquid [C2MIM][NTf2]. Our results reveal a strong correlation between the observables of DBS and the loading factor which presumably arises from a smaller inner surface of voids in loaded silica gel.
PALS and TEM Study on Irradiation Defects of 12Cr-ODS Steels Induced by He/H Ions
Authors: Han Lu Hui , Fa Tao , Zhao Ya Wen
Published: March 2017

The purpose of this study is to evaluate the irradiation defects of 12Cr-ODS steels induced by He/H ions, to provide basic understanding concerning development of fusion reactor components. Firstly, single He、H ion implantation and He/H ion co-implantation of 12Cr-ODS steels were performed at room temperature; and then SIMS were used to determine the He/H ion depth; finally, the irradiation induced defects were investigated by PALS and TEM. Characterization of the implanted samples with SIMS shows that He/H ions are mainly distributed at 4-6μm depth, consistent with the SRIM simulation. The PALS results show that the positron lifetime of H ions implanted samples increases slightly with increasing incident ions fluence, while for He and He/H ion implantation it is reversed. In addition, TEM results demonstrate that after irradiation, cavities are created in all samples, and He ion irradiation produce seriously larger damage compared to H ion. The positron lifetime results can be mainly ascribed to the difference of He and H ion interaction with defects.
New Technological Approach in Fabrication of High Purity Nickel Wire
Authors: Stuth Theodor , Theile Rainer , Krivtsova Oleksandra
Published: March 2017

Hpulcas
GmbH has developed a process of high purity nickel wire manufacturing directly from cathode plates without melting. This means significantly lower capital investments and energy costs as compared to the standard manufacturing technology by melting on the one hand and remaining of the high degree of purity on the other hand. Hpulcas wire is produced by the hot rolling of full cathode plates, slitting the plates into sticks, frontal joining and drawing.High purity nickel has such beneficial properties as microcleanliness, excellent mechanical and electrical properties and beneficial corrosion resistance. These properties have been used in batteries and fuel cell components, welding and brazing products, and sensing and controlling instruments.
Influence of Deformation Controlled Strain Rate on Tensile and Compression Behaviour of Magnesium and Steel Wire
Authors: Henseler Thorsten , Ullmann Madlen , Korpala Grzegorz , Klimaszewska Klaudia , Kawalla Rudolf , Berge Franz
Published: March 2017

This article demonstrates the difference in the flow curves of an AZ31 magnesium alloy and S235JR structural steel wire caused by non-linear strain rates during uniaxial tensile and compression testing at elevated temperatures. Throughout tensile deformation, the traverse velocity of the testing machine has to be adapted according to the current elongation of the specimen, thus accelerating, to ensure a constant strain rate during the admission of the stress-strain curve. The equivalent is necessary during compression testing, where the traverse velocity of the testing machine needs to decelerate ensuring a constant strain rate. Nevertheless, tensile and compression tests are performed with constant traverse velocity, which lead to divergent flow curves in comparison to deformation controlled traverse velocities. The results of the research show the difference in flow behaviour of magnesium and steel wire, when the temperature and strain rate are varied in conjunction with constant and deformation controlled traverse velocities.
Velcro compression devices
Authors: Caprini Joseph A.
Published: March 2017

Not available
Needing more: the case for extra high compression for tall men in UK leg ulcer management
Authors: Hopkins Alison , Bull Richard , Worboys Fran
Published: March 2017

Not available
Film compression bandage: a new modality to improve sclerotherapy of superficial varicosities
Authors: Ragg Johann Chris
Published: March 2017

Not available
Efesiërs 1:14 en 1:22, 23 as ’n skriftuurlike maksimum-minimum vir die ekklesiologie
Authors: Van Wyk Barry J.
Published: March 2017

Ephesians 1:14 and 1:22, 23 as a scriptural maximum-minimum for ecclesiology. Against the background of a membership decline in mainstream churches in South Africa and abroad, and conscious of the theological debate in which a missional ecclesiology is presented as at least part of the modern-day solution to the problem, this article points in the direction of a Christological ecclesiology as an important ecclesiological point of departure. The article gives an exegetical outline of Ephesians 1:14 and 1:22, 23 as a critical maximum-minimum for a Christological ecclesiology and as a means of making missional ecclesiology more acceptable.
Identification and phylogenetic analysis of contagious ecthyma virus from camels (Camelus dromedarius) in Iran
Authors: Oryan Ahmad , Mosadeghhesari Mahboobe , Zibaee Saeed , Mohammadi Ali
Published: March 2017

Contagious ecthyma is a highly contagious disease affecting domestic and wild ruminants such as sheep, goats and camels. The identification and characterisation of a parapoxvirus (PPV) infecting camels is described here. The virus was detected in dromedary camels (Camelus dromedarius) from Kerman and Shiraz in Iran. PPV-specific amplification by polymerase chain reaction (PCR) further confirmed that the disease was associated with PPV infection. Phylogenetic analysis of ORF011 (B2L) gene sequences showed 99.79% and 82.13% similarity of the PPV identified in this study with the Jodhpur isolate and the bovine papular stomatitis virus (BPSV) isolates (CE41), respectively. Moreover, phylogenetic analysis of the ORF045 gene indicated that the Shiraz sample was in all probability closely related to VR634 and to F00.120R and PCPV776. In conclusion, the results suggest that camel PPV (CPPV) is a likely cause of contagious ecthyma in dromedary camels in Iran.
African immigrants in South Africa: Job takers or job creators?
Authors: Kalitanyi Vivence
Published: March 2017

During the last decade African immigrants have been met with and exposed to severe forms of hostility towards their presence in this country. A significant number of these migrants have successfully applied their entrepreneurial flair in establishing small enterprises and employing workers, often to the envy of their local counterparts. This paper presents the findings of an empirical study conducted in 2007 on job creation by African immigrant entrepreneurs for South Africans with face-to-face interviews with 120 African immigrant entrepreneurs. These findings were triangulated 7 non-governmental organisations that interact with immigrants in Cape Town. A review of the literature on migration, entrepreneurship and immigrant entrepreneurs formed the basis for the study The findings indicate that more than 80% of African immigrant entrepreneurs interviewed employ South Africans in their businesses. Despite a generally negative national perception towards immigrants, this study has also revealed that entrepreneurial skills are transferred from immigrant entrepreneurs to their South African employees. Whilst the study was only conducted in the suburban areas of Cape Town, the researcher believes that the results represent the general trend for South Africa. Furthermore, the study only involved those migrants who come from African continent. The overall result is the acknowledgement of the contribution that non-citizens are making to the country’s growth and development. The findings suggest recommendations geared towards policy changes regarding South African immigration law, an inclusive research about the role of immigrants on job creation in South Africa, as well as the consideration of immigrant entrepreneurs when allocating financial support.
The challenge of low employment economic growth in South Africa: 1994 -2008
Authors: Mahadea Darma , Simson Richard
Published: March 2017

The formal sector in South Africa is unable to provide adequate employment for labour although the economy registered positive economic growth rates over the past 15 years since the demise of apartheid.  This is a critical problem, given the current recessionary climate and recent developments in the economies of our trading partners.  While government has responded with many initiatives to deal with employment creation, unemployment rates remain high.  This problem is examined by reviewing South Africa’s growth performance and links to employment and posits various alternative strategies.  The growth elasticity of employment is found to be rather low over the 1994-2008 period, and even over a longer time horizon the marginal growth employment effect is found to be rather weak.
Tax preferences, dividends and lobbying for maximum value
Authors: Badenhorst Wessel M.
Published: March 2017

Background: The value of equity investments depends to some extent on the tax consequences for investors. When groups of investors have different tax preferences, this can lead to conflicting pressures on firms to either retain earnings or pay dividends. The findings of this study will be of interest to researchers of taxation and corporate governance alike, as they highlight the role that corporate shareholders play in the decisions of the firm. Investors and regulators will also be interested in the findings as they reveal more about the interaction between shareholders with conflicting interests. Lastly, changes in behaviour as a result of changes in tax legislation are of interest to those with fiscal responsibility.Setting: A 2012 dividend tax change in South Africa, which simultaneously altered the tax preferences of individual and corporate investors, provides a unique opportunity to investigate firms’ reaction to their investors’ tax preferences.Aim: This article seeks to determine whether firms respond to changes in their investors’ tax preferences in their decisions to either retain earnings or pay dividends.Method: The article investigates the responses of firms to the 2012 dividend tax change using multivariate regressions.Results: Findings show that firms consider changes in the tax preferences of their investors in setting dividend policies. In addition, it appears that corporates have greater success in lobbying for beneficial dividend changes than individuals.Conclusion: Changes in investors’ tax preferences impact on firms’ dividend policy decisions. These decisions ultimately affect the value of the firm to its investors
The trimmed Anderson model at strong disorder: localisation and its breakup
Authors: Elgart Alexander , Sodin Sasha
Published: March 2017

We explore the properties of discrete random Schrödinger operators in which the random part of the potential is supported on a sub-lattice (the trimmed Anderson model). In this setting, Anderson localisation at strong disorder does not always occur; alternatives include anomalous localisation and, possibly, delocalisation. We establish two new sucient conditions for localisation at strong disorder as well as a sucient condition for its absence, and provide examples for both situations. The main technical ingredient is a pair ofWegner-type estimates which are applicable when the covering condition does not hold. Finally, we discuss a coupling between randomoperators at weak and strong disorder. This coupling is used in an heuristic discussion of the properties of the trimmed Anderson model for sparse sub-lattices, and also in a new rigorous proof of a result of Aizenman pertaining to weak disorder localisation for the usual Anderson model.
Spectral homogeneity of discrete one-dimensional limit-periodic operators
Authors: Fillman Jake
Published: March 2017

We prove that a dense subset of limit periodic operators have spectra which are homogeneous Cantor sets in the sense of Carleson. Moreover, by using work of Egorova, our examples have purely absolutely continuous spectrum. The construction is robust enough to extend the results to arbitrary p-adic hulls by using the dynamical formalism proposed by Avila. The approach uses Floquet theory to break up the spectra of periodic approximants in a carefully controlled manner to produce Cantor spectrum and to establish the lower bounds needed to prove homogeneity.
A solvability condition for a tokamak problem
Authors: Boumenir Amin
Published: March 2017

By using the matrix representation of the Laplacian, under Dirichlet and Robin boundary conditions, we recast a boundary inversion problem for the tokamak into a simple algebraic system. The solution is then obtained explicitly in terms of the Fourier coefficients of the observation.
An investigation on the origin of regional springtime ozone episodes in the western Mediterranean
Authors: Kalabokas Pavlos , Hjorth Jens , Foret Gilles , Dufour Gaëlle , Eremenko Maxim , Siour Guillaume , Cuesta Juan , Beekmann Matthias
Published: March 2017

Abstract. For the identification of regional springtime ozone episodes, rural European Monitoring and Evaluation Programme (EMEP) ozone measurements from countries surrounding the western Mediterranean (Spain, France, Switzerland, Italy, Malta) have been examined with emphasis on periods of high ozone-mixing ratios, according to the variation of the daily afternoon (12:00–18:00) ozone values. For two selected high ozone episodes in April and May 2008, composite NCEP/NCAR reanalysis maps of various meteorological parameters and/or their anomalies (geopotential height, specific humidity, vertical wind velocity omega, vector wind speed and temperature) at various tropospheric pressure levels have been examined together with the corresponding satellite Infrared Atmospheric Sounding Interferometer (IASI) ozone measurements (at 3 and 10 km), CHIMERE simulations, vertical ozone soundings and HYSPLIT back trajectories. The observations show that high ozone values are detected in several countries simultaneously over several days. Also, the examined spring ozone episodes over the western Mediterranean and in central Europe are linked to synoptic meteorological conditions very similar to those recently observed in summertime ozone episodes over the eastern Mediterranean (Kalabokas et al., 2013, 2015; Doche et al., 2014), where the transport of tropospheric ozone-rich air masses through atmospheric subsidence significantly influences the boundary layer and surface ozone-mixing ratios. In particular, the geographic areas with observed tropospheric subsidence seem to be the transition regions between high-pressure and low-pressure systems. During the surface ozone episodes IASI satellite measurements show extended areas of high ozone in the lower- and upper-troposphere over the low-pressure system areas, adjacent to the anticyclones, which influence significantly the boundary layer and surface ozone-mixing ratios within the anticyclones by subsidence and advection in addition to the photochemically produced ozone there, resulting in exceedances of the 60 ppb standard.
An automated method for the evaluation of the pointing accuracy of Sun-tracking devices
Authors: Baumgartner Dietmar J. , Pötzi Werner , Freislich Heinrich , Strutzmann Heinz , Veronig Astrid M. , Rieder Harald E.
Published: March 2017

Abstract. The accuracy of solar radiation measurements, for direct (DIR) and diffuse (DIF) radiation, depends significantly on the precision of the operational Sun-tracking device. Thus, rigid targets for instrument performance and operation have been specified for international monitoring networks, e.g., the Baseline Surface Radiation Network (BSRN) operating under the auspices of the World Climate Research Program (WCRP). Sun-tracking devices that fulfill these accuracy requirements are available from various instrument manufacturers; however, none of the commercially available systems comprise an automatic accuracy control system allowing platform operators to independently validate the pointing accuracy of Sun-tracking sensors during operation. Here we present KSO-STREAMS (KSO-SunTRackEr Accuracy Monitoring System), a fully automated, system-independent, and cost-effective system for evaluating the pointing accuracy of Sun-tracking devices. We detail the monitoring system setup, its design and specifications, and the results from its application to the Sun-tracking system operated at the Kanzelhöhe Observatory (KSO) Austrian radiation monitoring network (ARAD) site. The results from an evaluation campaign from March to June 2015 show that the tracking accuracy of the device operated at KSO lies within BSRN specifications (i.e., 0.1° tracking accuracy) for the vast majority of observations (99.8 %). The evaluation of manufacturer-specified active-tracking accuracies (0.02°), during periods with direct solar radiation exceeding 300 W m−2, shows that these are satisfied in 72.9 % of observations. Tracking accuracies are highest during clear-sky conditions and on days where prevailing clear-sky conditions are interrupted by frontal movement; in these cases, we obtain the complete fulfillment of BSRN requirements and 76.4 % of observations within manufacturer-specified active-tracking accuracies. Limitations to tracking surveillance arise during overcast conditions and periods of partial solar-limb coverage by clouds. On days with variable cloud cover, 78.1 % (99.9 %) of observations meet active-tracking (BSRN) accuracy requirements while for days with prevailing overcast conditions these numbers reduce to 64.3 % (99.5 %).
Dust impact on surface solar irradiance assessed with model simulations,
satellite observations and ground-based measurements
Authors: Kosmopoulos Panagiotis G. , Kazadzis Stelios , Taylor Michael , Athanasopoulou Eleni , Speyer Orestis , Raptis Panagiotis I. , Marinou Eleni , Proestakis Emmanouil , Solomos Stavros , Gerasopoulos Evangelos , Amiridis Vassilis , Bais Alkiviadis , Kontoes Charalabos
Published: March 2017

Abstract. This study assesses the impact of dust on surface solar radiation focussing on an extreme dust event. For this purpose, we exploited the synergy of AERONET measurements and passive and active satellite remote sensing (MODIS and CALIPSO) observations, in conjunction with radiative transfer model (RTM) and chemical transport model (CTM) simulations and the 1-day ahead forecasts from the Copernicus Atmosphere Monitoring Service (CAMS). The area of interest is the eastern Mediterranean where anomalously high aerosol loads were recorded between the 30 January and 3 February 2015. The intensity of the event was extremely high, with aerosol optical depth (AOD) reaching 3.5, and optical/microphysical properties suggesting aged dust. RTM and CTM simulations were able to quantify the extent of dust impact on surface irradiances and reveal substantial reduction in solar energy exploitation capacity of PV and CSP installations, under this high aerosol load. We found that such an extreme dust event can result to Global Horizontal Irradiance (GHI) attenuation by as much as 40–50 %, a much stronger Direct Normal Irradiance (DNI) decrease (80–90 %), while spectrally this attenuation is distributed to 37 % in the UV region, 33 % to the visible and around 30 % to the infrared. CAMS forecasts provided a reliable available energy assessment (accuracy within 10 % of that obtained from MODIS). Spatially, the dust plume resulted in a zonally-averaged reduction of GHI and DNI of the order of 150 W/m2 in southern Greece, and a mean increase of 20 W/m2 in the northern Greece as a result of lower AOD values combined with local atmospheric processes. This analysis of a real-world scenario contributes to the understanding and quantification of impact range of high aerosol loads on solar energy and the potential for forecasting power generation failures at sunshine-privileged locations where solar power plants exist, are under construction, or being planned.