bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effects of Ocular Perfusion Pressure Variations on a Case of Circumscribed Choroidal Hemangioma Affected by Primary Open-Angle Glaucoma
Authors: Cutolo Carlo Alberto , Ancona Chiara , Iester Michele , Traverso Carlo Enrico , Nicolò Massimo
Published: May 2019

The authors describe the clinical and anatomical correlation between mean ocular perfusion pressure (MOPP) changes and macular exudation in a 62-year-old man affected by circumscribed choroidal hemangioma (CCH) and primary open-angle glaucoma. During the 5-year follow-up, we noted an increase of the subretinal fluid (SRF) and cystoid macular edema (CME) when the intraocular pressure (IOP) was in the low teens. Optical coherence tomography scans performed during an isometric exercise revealed a transient increase of the retinal (choroidal) thickness. In the presented case, MOPP appears to play a role in SRF and CME associated with CCH. Management of the macular exudation could improve if IOP and blood pressure are considered and treated accordingly.

[
Ophthalmic Surg Lasers Imaging Retina
. 2019;50:e163–e165.]
An Assembly Line Balancing Application on Oven Production Line with Hyper-Heuristics
Authors: Seçme Gökhan , Özbakır Lale
Published: May 2019

In this study, an oven assembly line that is planning to re-establish manufacturing to increase the efficiency of the assembly process. The importance of the problem emerges from a real-world application consisting of product-oriented restrictions. These multiple restricted problems address the single model assignment restricted ALB problem with positional constraints. A cost-based objective function is used to cope with this problem. The number of platformed and non-platformed stations, the number of direction changes in a station, the number of stations in which both connector and combiner are used are the cost factors of the objective function. Also, the main objective of the problem is to minimize the total number of stations while satisfying the restrictions. A simulated annealing-based hyper-heuristic is adapted and applied to the balancing problem of oven manufacturing process with assignments and operational restrictions with multiple objectives. The results show that better solutions can be found in the current line balance level while satisfying more restrictions. It is also observed that line balance can be improved depending on the relaxation of the restrictions.
Repair of Damages that Occurred on the Welded Joints at the Body of Guide Vane Apparatus Vanes of the Vertical Kaplan Turbine
Authors: Arsić Miodrag , Bošnjak Srđan M. , Grabulov Vencislav , Mladenović Mladen , Savić Zoran
Published: May 2019

Vertical Kaplan turbines, with nominal power of 178 MW and manufactured in Russia, have been installed in 6 hydroelectric generating units of hydro power plant ’Djerdap 1’. Experimental tests were carried out by non-destructive methods in order to determine the turbine condition during the rehabilitation of the hydro power plant. Lack of root penetration was detected in V40 welded joints between upper and lower sleeves and bodies of guide vane apparatus vanes. Height of the lack of root penetration was in the range between 5 and 15 mm, while the allowable height of the lack of root penetration is 3 mm, according to the technical conditions. The upper sleeves were made of cast steel 25L (in accordance with GOST 977), while lower sleeves were made of steel forging St 25 (in accordance with standards GOST 1050 for chemical composition and GOST 8479 for forgings).Methodology for the repair of non-penetrated welded joints between the sleeves and body of the guide vane apparatus vane was composed taking into account the results of ultrasonic testing. By repair methodology it is necessary to, due to the structural solution and service function of guide vane apparatus vanes, specify a large number of details, consider them carefully and carry them out in order to improve safety, because if some of them get overlooked, underestimated or incorrectly perceived, significant problems in turbine operation may occur.This methodology refers solely to the repair of damaged welded joints between sleeves and bodies of guide vane apparatus vanes.
The Welded Structural Designer and the Decision-Making Process in Specific Critical Details Dynamically Loaded Welded Structures Susceptible to Fatigue
Authors: Băncilă Radu , Feier Anamaria , Dascău Horia
Published: May 2019

The paper will try to evidence the importance and the role of the Welded Structural Designer and explain also the critical joints to the dynamically loaded welded structures susceptible to fatigue. In case of the important structures the decision of the Welded Structural Designer is essential, because his decision allows the change the type of joints, the type of materials.
Study on some Behavioral Particularities of the Piezoceramic Elements from the Ultrasonic Converter Construction
Authors: Dumitru Mnerie , Mnerie Gabriela-Victoria
Published: May 2019

The ultrasound processing is in continuous development, always bringing better technological solutions. Ultrasonic welding occupies an important place within this category of processing. The present study focuses on some piezoceramic materials that represent the active elements in the structure of the required energy generator on which ultrasonic welding is based in fact. Using the analytical method of investigation, several aspects of piezoceramic material structural behavior during the exploitation were followed, both at macroscopic and microscopic level. Some causes and effects of changes to their functionality have been analyzed. The paper concludes with observations and recommendations on optimizing the manufacture and use of piezoceramic materials intended for converter construction for ultrasonic welding.
Technical Characteristics of the Equipment for Friction Stir Welding (FSW), Depending on the Base Metals
Authors: Verbiţchi Victor , Cojocaru Radu , Boţilă Lia Nicoleta
Published: May 2019

There are various base metals that might be subjected to friction stir welding (FSW). They have different yield strength, ultimate tensile strength and other mechanical characteristics that influence the complex phenomena of the FSW process. The nature, mechanical characteristic and other properties of the base metals introduce also certain requirements for the FSW equipment, because FSW is a mechanical process.Experimental data of the FSW of the following materials are presented and compared:- similar overlapped sheets of aluminium alloy EN AW 5754, having the thickness 1.0 mm; - dissimilar overlapped sheets of 3 - 6 mm thickness of the base metal couples: aluminium alloy EN AW 1200 / copper Cu 99 ET, aluminium alloy EN AW 5754 / copper Cu 99, aluminium alloy EN AW 6082 / copper Cu 99 ET;- sheets of nickel alloy, inconel 718, thickness 8 - 10 mm, by friction stir processing. The characteristics of the FSW tool are described and the main technology parameters are mentioned: overlap, rotational speed of the FSW tool, rotational direction, travel speed, thrust force, as well as electric current of the motor for the rotating motion of the tool.Other important factors are also taken into account: sizes and positioning of the sheets (up or down), rolling direction of the sheets, room temperature, temperature of the sheets, material and temperature of the support plate.The linear energy of the FSW process is the main parameter. This is an indirect parameter, because it must be calculated, based on the previous mentioned parameters. According to the definition, the linear energy depends directly on the mechanical power developed during the stirring process, respectively it depends indirectly on the travel speed.On the other hand, the heat input is directly proportional to the linear energy and the thermal efficiency of the transfer of the heat produced by the friction of the shoulder and pin, to the nugget zone, where the weld metal is produced. These quantities are also analysed.For these materials the power developed by the motor for the rotational movement is determined, as well as the mechanical torque applied to the FSW tool. All these data are important for the design of the FSW equipment, in order to realize its main technical characteristics, depending on the base metals.Conclusions on the results are exposed, with important consequences for the industrial applications of the FSW process.
Method and Technologies Functional Constructive Configuration Concept of a Flexible Unconventional Hybrid FSW-US Welding Process
Authors: Oancă Octavian Victor , Sîrbu Nicuşor Alin , Binchiciu Emilia-Florina , Mnerie Gabriela-Victoria , Perianu Ion Aurel
Published: May 2019

The hybrid unconventional technology friction stir welding assisted by ultrasonic vibration (FSW-US) is a technology that is of interest internationally, it provides certain advantages in improving the behavior of welding components during their processing, as well as their mechanical properties and quality of joints resulted from our experiments. Within ISIM Timisoara, we aim to develop specialized non-conventional welding technologies and experimental modules (FSW-US) designed to make joints for metallic and non-metallic materials, with industrial and applications pre-competitive.
Research on the Welding Behavior for Alloy EN AW 5754 when Using FSW-US Hybrid Process
Authors: Oancă Octavian Victor , Mnerie Gabriela-Victoria , Binchiciu Emilia-Florina , Cojocaru Radu , Boţilă Lia Nicoleta , Duma Iuliana
Published: May 2019

We approached a new hybrid technology that integrates ultrasonic energy with FSW welding. By integrating ultrasound in the FSW process, a number of benefits are expected in terms of welding quality, forces and tool life. Our research aimed at developing a new technique of friction stir welding assisted by ultrasonic energy, namely FSW-US, which can improve the process, it can contribute to the decrease of forces that develop during the welding process and can increase the quality of welded joints. Metal welding and processing technologies that use ultrasonic vibrations, either as a primary source to achieve prescribed performance, or as a source of assistance to improve the efficiency of the operation and product quality, are currently being researched or discussed in the international scientific environment. The present paper analyzes the effects of overlapping ultrasonic vibrations with heat generation, temperature distribution and material flow generated by applying the FSW process. Mechanical effect plays a dominant role in the welding process assisted by ultrasonic vibrations, while thermal effects are insignificant. Overlapping ultrasonic vibrations on the friction stir welding process can produce a stream of improved plasticized material, increases the welding speed and efficiency, it can also improve weld quality by increasing the flow / volume of plastic material around the tool. [1]
An Improved 4H-SiC Trench Gate MOSFETs Structure with Low On-Resistance and Reduced Gate Charge
Authors: Tian Kai , Xia Jing Hua , Qi Jin Wei , Ma Shen Hui , Yang Fei , Zhang An Ping
Published: May 2019

In this paper, an improved 4H-SiC trench-gate metal-oxide-semiconductor field effect transistors (UMOSFETs) structure with low on-resistance and reduced gate charge is proposed. The added n-type region in the improved structure reduces on-resistance of the device significantly while maintaining same breakdown voltage. The gate of the improved structure is designed as a p-n junction to reduce the gate-charge. The specific on-resistances of the improved 4H-SiC UMOSFETs is 1.87 mΩ.cm2 at VGS=18 V and VDS=10 V, compared with 4.48 mΩ.cm2 for the conventional p+ shielding UMOSFETs structure with same breakdown voltage. The on-resistance and figure of merit (FOM = VBR2/Ron) improve by 58.3% and 103.6%, respectively. Compared with the conventional structure, the results show that gate-drain charge of the improved structure can be improved by 23.8%.
Effect of Tunneling on Small Signal Characteristics of IMPATT Diodes with SiC Heteropolytype Structures
Authors: He Ming Chang , Hu Li Xia , Zheng Jun Ding , Wei Wen Sheng , Xiao Hai Lin , Ye Jian Zhu , Qiao Guan Jun
Published: May 2019

SiC heteropolytype structures indicate important applications in high frequency, large power solid devices etc. In this paper, the impact avalanche transit time (IMPATT) and mixed tunneling avalanche transit time (MITATT) diodes with heteropolytype consisting of two semiconductors among the 3C-SiC, 4H-SiC and 6H-SiC are numerically simulated to investigate the static state and small signal characteristics at the atmospheric window frequency of 1.56 THz. The breakdown voltage, avalanche voltage, peak value of static electric field, the maximum generation rates of avalanche and tunneling, power conversion efficiency, admittance-frequency relation of the proposed SiC heteropolytype diodes are calculated, respectively. Comparing the obtained parameters of IMPATT diodes with those of MITATT devices, the results imply that tunneling shows little influence on the small signal performance of the heteropolytype IMPATT diodes included 3C-SiC material, which is different from those of the homopolytype counterparts.
Effect of Growth Chamber Structure on the Growth of Aluminum Nitride Crystals
Authors: Lu Zheng Qian , Qu Yi Pu , Niass Mussaab I. , Sharif Muhammad Nawaz , Liu Yu Huai , Wang Fang
Published: May 2019

AlN crystals are one of the representative III-V group semiconductor materials. AlN has good electric field characteristics, thermal conductivity and thermal stability. Owing to its wide direct band gap of 6.2eV [1], it can achieve a luminescent wavelength of 210 nanometers in deep ultraviolet, which is an ideal material for UV and deep UV LED devices. But preparation of AlN crystals with PVT for growing conditions demanding, 0.3-0.5 atm of high purity nitrogen atmosphere of growth and the growth of 2100-2400 K temperature [2, 3]. In this paper, two kinds of growth chamber structures are designed and compared. In order to ensure that the temperature gradient between the source material surface and the seed surface satisfy the crystal growth and keep stability in the larger transverse region, [4, 5] the crystal grown on the seed crystal can get better quality.
Homoepitaxial Growth on Si-Face (0001) On-Axis 4H-SiC Substrates
Authors: Yan Guo Guo , Liu Xing Fang , Zhang Feng , Shen Zhan Wei , Zhao Wan Shun , Wang Lei , Cui Ying Xin , Li Jun Tao , Sun Guo Sheng
Published: May 2019

Homoepitaxial growths of 4H-SiC were performed on Si-face (0001) on-axis substrates in a SiH4-C2H4-H2-HCl system by using our home-made vertical hot wall CVD reactor. The influence mechanism of the growth temperature and C/Si ratio on the morphology and growth rate was studied. It is found that the steps in the epilayer become more clear with the increasing temperatures. The result indicates that the C/Si ratio window of on-axis epitaxial growth is very narrow. Only when the C/Si ratio was 1.2, a slightly improved surface morphology can be achieved. The results indicate that 4H-SiC epitaxial layers were obtained on on-axis substrates and the films were highly-oriented 4H-SiC.
Healthy Donors Exhibit a CD4 T Cell Repertoire Specific to the Immunogenic Human Hormone H2-Relaxin before Injection
Authors: Azam Aurélien , Gallais Yann , Mallart Sergio , Illiano Stephane , Duclos Olivier , Prades Catherine , Maillère Bernard
Published: May 2019

H2-relaxin (RLN2) is a two-chain peptide hormone structurally related to insulin with a therapeutic potential in multiple indications. However, multiple injections of human RLN2 induced anti-RLN2 Abs in patients, hampering its clinical development. As T cell activation is required to produce Abs, we wondered whether T cells specific for RLN2 might be already present in the human blood before any injection. We therefore quantified the RLN2-specific T cell repertoire using PBMCs collected from healthy donors. CD4 T cells were stimulated in multiple replicates by weekly rounds of stimulation by dendritic cells loaded with RLN2, and their specificity was assessed by IFN-γ ELISPOT. The number of specific T cell lines was used to estimate the frequency of circulating T cells. In vitro T cell response was demonstrated in 18 of the 23 healthy donors, leading to the generation of 70 independent RLN2-specific T cell lines. The mean frequency of RLN2-specific CD4 T cells was similar to that of T cells specific for known immunogenic therapeutic proteins. Using overlapping peptides, we identified multiple T cell epitopes hosted in the N-terminal parts of the α- and β-chains and common to multiple donors, in agreement with their capacity to bind to multiple HLA-DR molecules. Our results provide important clues to the immunogenicity of RLN2 and highlight the weak central immune tolerance induced against this self-hormone.
Phosphorylation at S2053 in Murine (S2056 in Human) DNA-PKcs Is Dispensable for Lymphocyte Development and Class Switch Recombination
Authors: Jiang Wenxia , Estes Verna M. , Wang Xiaobin S. , Shao Zhengping , Lee Brian J. , Lin Xiaohui , Crowe Jennifer L. , Zha Shan
Published: May 2019

The classical nonhomologous end-joining (cNHEJ) pathway is a major DNA double-strand break repair pathway in mammalian cells and is required for lymphocyte development and maturation. The DNA-dependent protein kinase (DNA-PK) is a cNHEJ factor that encompasses the Ku70–Ku80 (KU) heterodimer and the large DNA-PK catalytic subunit (DNA-PKcs). In mouse models, loss of DNA-PKcs (DNA-PKcs−/−) abrogates end processing (e.g., hairpin opening), but not end-ligation, whereas expression of the kinase-dead DNA-PKcs protein (DNA-PKcsKD/KD) abrogates end-ligation, suggesting a kinase-dependent structural function of DNA-PKcs during cNHEJ. Lymphocyte development is abolished in DNA-PKcs−/− and DNA-PKcsKD/KD mice because of the requirement for both hairpin opening and end-ligation during V(D)J recombination. DNA-PKcs itself is the best-characterized substrate of DNA-PK. The S2056 cluster is the best-characterized autophosphorylation site in human DNA-PKcs. In this study, we show that radiation can induce phosphorylation of murine DNA-PKcs at the corresponding S2053. We also generated knockin mouse models with alanine- (DNA-PKcsPQR) or phospho-mimetic aspartate (DNA-PKcsSD) substitutions at the S2053 cluster. Despite moderate radiation sensitivity in the DNA-PKcsPQR/PQR fibroblasts and lymphocytes, both DNA-PKcsPQR/PQR and DNA-PKcsSD/SD mice retained normal kinase activity and underwent efficient V(D)J recombination and class switch recombination, indicating that phosphorylation at the S2053 cluster of murine DNA-PKcs (corresponding to S2056 of human DNA-PKcs), although important for radiation resistance, is dispensable for the end-ligation and hairpin-opening function of DNA-PK essential for lymphocyte development.
T Cell–Dependent Maturation of Pathogen-Specific Igs in the Antrum of Chronically Helicobacter pylori–Infected Patients
Authors: Neumann Laura , Moos Verena , Giesecke-Thiel Claudia , Dörner Thomas , Ignatius Ralf , Allers Kristina , Aebischer Toni , Schneider Thomas
Published: May 2019

Mucosal plasma cells (PC) and Ig production are essential to fend pathogens and to maintain mucosal homeostasis. In human Helicobacter pylori infection, mucosal PC express inducible NO synthase (iNOS), which positively correlates with clearance of experimental human infection. To characterize Ig genes and specificities of antral mucosal iNOS+ and iNOS− PC in H. pylori infection, we sequenced rearranged Ig genes from single cell–sorted PC from biopsy specimens of chronically infected patients and analyzed them with respect to their molecular features. The binding specificity of individual PC’s Ig was determined following recombinant expression. We identified high rates of somatic hypermutations, especially targeting RGYW/WRCY hotspot motifs in the individual Ig genes, indicating T cell–dependent maturation. For seven of 14 recombinantly expressed Ig, Ag specificity could be determined. Two clones reacted to H. pylori proteins, and five were found to be polyreactive against LPSs, dsDNA, and ssDNA. All specific Ig originated from iNOS+ PC. H. pylori–specific Ig are encoded by V and J family genes previously shown to be also used in rearranged Ig loci of MALT B cell lymphomas. In summary, mucosal iNOS+ PC producing H. pylori–specific Ig accumulate in infection and appear to be a product of T cell–dependent B cell maturation. Moreover, the Ig’s molecular features partly resembled that of MALT B cell lymphoma Ig genes, suggestive of a mechanism in which a progressive molecular evolution of pathogen-specific B cells to MALT B cell lymphoma occurs.
Screening colonoscopy in Port Harcourt, Nigeria
Authors: Ray-Offor Emeka , Abdulkareem Fatimah B.
Published: May 2019

Colonoscopy is a screening tool for colorectal cancer. The cost of this service, ready availability and expertise are factors limiting its routine use in low-/middle-income countries. The aim was to study premalignant colonic polyps in asymptomatic middle-aged Nigerians and highlight the usefulness of screening colonoscopy in a sub-Saharan African population. We carried out an observational study on asymptomatic patients undergoing screening colonoscopy in a referral endoscopy facility in Port Harcourt, Rivers State, Nigeria from January to December 2018. The variables collated were demographics, endoscopic and histologic findings. Statistical analysis was done using IBM SPSS Statistics for Windows, version 20 Armonk, NY. A total of 144 colonoscopy procedures were performed during the study period with 70 asymptomatic cases for screening indication. Sixty-five were males and 5 females. The age range was from 48 years to 60 years; mean 54.8 ± 3.6 years. A polyp-detection rate of 53.7% was recorded with multiple polyps seen in 13 cases. Adenoma(s) detected in 19 persons were: 22 tubular adenomas with low grade dysplasia; 3 tubulo-villous adenomas with low grade dysplasia; 1 sessile serrated adenoma. The adenoma detection rate was 28.8%. No abnormality was detected in 19 cases. There is a worrisome prevalence of adenomatous polyps; villous adenoma is rare. A targeted policy of screening and surveillance by colonoscopy will curb the rising incidence of colorectal cancer.
Regional tax effort in Spain
Authors: Zárate-Marco Anabel , Vallés-Giménez Jaime
Published: May 2019

This work examines in depth the hypotheses explaining the tax capacity of regional governments, also determining their tax effort and explanatory factors. The study is done for the Spanish regions, using different techniques which have rarely been applied in this area. The results show that these jurisdictions have exercised their tax autonomy responsibly, in response to different budget and demographic factors and to the economic cycle. Also, an asymmetrical tax behaviour linked to income is observed: some regions have practically exhausted the possibilities of current sub-central taxes, while others still have ample fiscal space.
Significant decline of mesospheric water vapor at the NDACC site near Bern in the period 2007 to 2018
Authors: Lainer Martin , Hocke Klemens , Eckert Ellen , Kämpfer Niklaus
Published: May 2019

Abstract. The middle atmospheric water vapor radiometer MIAWARA is located close to
Bern in Zimmerwald (46.88∘ N, 7.46∘ E; 907 m)
and is part of the Network for the Detection of Atmospheric Composition
Change (NDACC). Initially built in the year 2002, a major upgrade of the
instrument's spectrometer allowed middle atmospheric water vapor to be
continuously measured since April 2007. Thenceforward to May 2018, a time
series of more than 11 years has been gathered, that makes a first trend
estimate possible. For the trend estimation, a robust multilinear parametric
trend model has been used. The trend model encompasses a linear term, a solar
activity tracker, the El Niño–Southern Oscillation (ENSO) index and the
Quasi-Biennial Oscillation (QBO) as well as the annual and semi-annual
oscillation. In the time period April 2007 to May 2018 we find a significant
decline in water vapor by -0.6±0.2 ppm per decade between 61 and
72 km. Below the stratopause level (∼48 km) a smaller
reduction of H2O of up to -0.3±0.1 ppm per decade is detected.
Segregation in the Atmospheric Boundary Layer: The Case of OH – Isoprene
Authors: Dlugi Ralph , Berger Martina , Mallik Chinmay , Tsokankunku Anywhere , Zelger Michael , Acevedo Otávio C. , Bourtsoukidis Efstratios , Hofzumahaus Andreas , Kesselmeier Jürgen , Kramm Gerhard , Marno Daniel , Martinez Monica , Nölscher Anke C. , Ouwersloot Huug , Pfannerstill Eva Y. , Rohrer Franz , Tauer Sebastian , Williams Jonathan , Yáñez-Serrano Ana-Maria , Andreae Meinrat O. , Harder Hartwig , Sörgel Matthias
Published: May 2019

Abstract. In the atmospheric boundary layer (ABL), incomplete mixing (i.e., segregation) results in reduced chemical reaction rates compared to those expected from mean values and rate constants derived under well mixed conditions. Recently, segregation has been suggested as a potential cause of discrepancies between modelled and measured OH radical concentrations, especially under high isoprene conditions. Therefore, the influence of segregation on the reaction of OH radicals with isoprene has been investigated by modelling studies and one ground-based and one aircraft campaign. In this study, we measured isoprene and OH radicals with high time resolution in order to directly calculate the influence of segregation in a low-NOx and high-isoprene environment in the central Amazon basin. The calculated intensities of segregation (Is) at the Amazon Tall Tower Observatory (ATTO) above canopy top are in the range of values determined at a temperate deciduous forest (ECHO-campaign) in a high-NOx low-isoprene environment, but stay below 10 %. To establish a more general idea about the causes of segregation and their potential limits, further analysis was based on the budget equations of isoprene mixing ratios, the variance of mixing ratios, and the balance of the intensity of segregation itself. Furthermore, it was investigated if a relation of Is to the turbulent isoprene surface flux can be established theoretically and empirically, as proposed previously. A direct relation is not given and the amount of variance in Is explained by the isoprene flux will be higher the less the influence from other processes (e.g., vertical advection) is and will therefore be greater near the surface. Although ground based values of Is from ATTO and ECHO are in the same range, we could identify different dominating processes driving Is. For ECHO the normalized variance of isoprene had the largest contribution, whereas for ATTO the different transport terms expressed as a residual were dominating. To get a more general picture of Is and its potential limits in the ABL, we also compared these ground based measurements to ABL modelling studies and results from an aircraft campaign. The ground based measurements show the lowest values of the degree of inhomogenous mixing (
Effect of NOx on 1,3,5-trimethylbenzene (TMB) oxidation product distribution and particle formation
Authors: Hammes Julia , Tsiligiannis Epameinondas , Mentel Thomas F. , Hallquist Mattias
Published: May 2019

Abstract. Secondary organic aerosol (SOA) represents a significant fraction of the tropospheric aerosol and its precursors are volatile organic compounds (VOC). Anthropogenic VOCs (AVOC) dominate the VOC budget in many urban areas with 1,3,5-trimethylbenzene (TMB) being among the most reactive aromatic AVOCs. TMB formed highly oxygenated organic molecules (HOM) in NOx free environment, which could contribute to new particle formation (NPF) depending on oxidation conditions were elevated OH oxidation enhanced particle formation. The experiments were performed in an oxidation flow reactor, the Go : PAM unit, under controlled OH oxidation conditions. By addition of NOx to the system we investigated the effect of NOx on particle formation and on the product distribution. We show that the formation of HOM and especially HOM accretion products, strongly varies with NOx conditions. We observe a suppression of HOM and particle formation with increasing NOx / ΔTMB and an increase in the formation of organonitrates (ON) mostly at the expense of HOM accretion products. We propose reaction mechanisms/pathways that explain the formation and observed product distributions with respect to oxidation conditions. We hypothesize that, based on our findings from TMB oxidation studies, aromatic AVOCs may not contribute significantly to NPF under typical NOx / AVOC conditions found in urban atmospheres.
Negligible influence of livestock contaminants and sampling system on ammonia measurements with cavity ring-down spectroscopy
Authors: Kamp Jesper Nørlem , Chowdhury Albarune , Adamsen Anders Peter S. , Feilberg Anders
Published: May 2019

Abstract. Emission of ammonia (NH3) is a ubiquitous problem
due to the adverse effects of NH3 on the environment and human
health. The agricultural sector accounts for nearly all NH3
emissions in Europe. Hence, technologies for the abatement of NH3
emissions from this sector have been in strong demand in recent years. In
order to document emissions and evaluate abatement technologies, there is
a strong need for reliable NH3 measurement methods. Photoacoustic
spectroscopy (PAS) is often used to measure NH3 concentrations, but
recent research shows interference from compounds typically present in
livestock production and during agricultural activities. In this work, the
performance of cavity ring-down spectroscopy (CRDS) from Picarro, as an
alternative to PAS, has been tested with respect to method validation under
laboratory and field conditions. Potential interferences of 10 volatile
organic compounds (VOCs) on CRDS NH3 measurement were tested with
simultaneous VOC analysis performed by proton-transfer-reaction mass
spectrometry (PTR-MS). Both laboratory and field calibrations show excellent
linearity over a large dynamic range of NH3 concentrations. The
analyzer shows a small humidity effect of up to a few ppb in the extreme
case of a nearly water-saturated air stream. Apart from the negligible
humidity dependency, no interferences of the tested VOCs were observed.
Overall, the CRDS system performs satisfactory and is well suited for
measurements of NH3 emissions from livestock production.
Combined use of volume radar observations and high-resolution numerical weather predictions to estimate precipitation at the ground: methodology and proof of concept
Authors: Le Bastard Tony , Caumont Olivier , Gaussiat Nicolas , Karbou Fatima
Published: May 2019

Abstract. The extrapolation of the precipitation to the ground from radar reflectivities measured at the beam altitude is one of the most delicate phases of radar data processing for producing Quantitative Precipitation Estimations (QPEs) and remains a major scientific issue. In many operational meteorological services such as Météo-France, a Vertical Profile of Reflectivity (VPR) correction is uniformly applied over a large part or the entire radar domain. This method is computationally efficient and the overall bias induced by the bright band is most of the time well corrected. However, this way of proceeding is questionable in situations with high spatial and vertical variability of precipitation (during the passage of a cold front or in a complex terrain, for example). This study initiates from two statements: first, radars provide information on precipitation with a high spatio-temporal resolution but still require VPR corrections to extrapolate rain rates at the ground level. Second, the horizontal resolution of some Numerical Weather Prediction (NWP) models is now comparable with the radar one and their dynamical core and microphysics schemes allow to produce realistic simulations of VPRs. The present paper proposes a new approach to assess surface rainfall from radar reflectivity aloft by exploiting simulated VPRs and rainfall forecasts from the high resolution NWP model AROME-NWC. To our knowledge, this is the first time that simulated precipitation profiles from a NWP model are used to derive radar QPEs. The implementation of the new method on two stratiform situations provided significant improvements on the hourly and 6-h accumulations compared to the operational QPEs, showing the relevance of this new approach.
The Trace Element Composition of Size Fractionated Suspended Particulate Matter Samples from the Qatari EEZ of the Arabian Gulf: The Role of Atmospheric Dust
Authors: Yigiterhan Oguz , Al-Ansari Ebrahim Mohd , Nelson Alex , Abdel-Moati Mohamed Alaa , Turner Jesse , Alsaadi Hamood Abdulla , Paul Barbara , Al-Maslamani Ibrahim Abdullatif , Al-Ansi Al-Yafei Mehsin Abdulla , Murray James Wray
Published: May 2019

Abstract. We analyzed net-tow samples of natural assemblages of plankton, and associated particulate matter, from the Exclusive Economic Zone (EEZ) of Qatar in the Arabian Gulf. Size fractioned suspended particles were collected using net-tows with mesh sizes of 50 μm (phytoplankton) and 200 μm (zooplankton) to examine the composition of plankton populations. Samples were collected in two different years (October 2012; April and October 2014) from 11 sites to examine temporal and spatial variabilities. We calculated the excess metal concentrations by correcting the bulk composition for inputs from atmospheric dust using aluminum (Al) as a lithogenic tracer and the metal / Al ratios for average Qatari dust. Atmospheric dust in Qatar is depleted in Al and enriched in calcium (Ca) relative to global average Upper Continental Crust (UCC) due to the geology of the outcropping sedimentary rocks and topsoil deposits in the source areas of the dust. To evaluate the fate of this carbonate fraction when dust particles enter seawater is uncertain, we leached a sub-set of dust samples using an acetic acid-hydroxylamine hydrochloride (HAc-HyHCl) procedure that should solubilize CaCO3 minerals and associated elements. We found that Ca was removed and that the metal/aluminum (Me / Al) ratios for most elements increased after leaching because the change in sample mass resulting from the leach was more important than the loss of metals solubilized by the leach. Because surface seawater is supersaturated with respect to CaCO3 and acid soluble Ca is abundant in the particulate matter, we only used unleached dust for the lithogenic correction. The concentrations of some elements in net-tow plankton samples appear to be mostly of lithogenic (dust) origin. These include Al, Fe, Cr, Co, Mn, Ni, Pb and Li. Several elements are mostly biogenic/anthropogenic origin. These include as Cd, Cu, Mo, Zn and Ca. The excess concentrations, relative to average dust, for most elements (except Cd) decreased with distance from shore, which may be due to differences in biology, currents, proximity to the coast or interannual processes.
A methodology for estimating the response of the coastal ocean to
meteorological forcing: A case study in the Bohai Bay
Authors: Wang Daosheng , Pan Haidong , Mu Lin , Lv Xianqing , Yan Bing , Yang Hua
Published: May 2019

Abstract. The sea level (SL) variations at the coastal ocean result from multiscale processes and are substantially contributed by the SL changes due to the meteorological forcing. In this study, a new methodology, named as IBR, is developed to estimate the response of the coastal ocean to meteorological forcing. The response is taken as the combination of the static ocean response calculated using the inverted barometer formula and the dynamic ocean response estimated using the multivariable linear regression involving atmospheric pressure and wind component at the dominant wind orientation. The dominant wind orientation is determined based on the averaged values of the magnitude squared coherences between the adjusted SL and wind at every wind orientation. The IBR is implemented to estimate the response of the coastal ocean at two stations, E1 and E2 in the Bohai Bay, China. The analysed results indicate that at both E1 and E2, the adjusted SLs are related more to the regional wind, which is the averaged value in the Bohai Bay of the 10 m wind in the ERA-Interim data, than to the local wind; the dominant regional wind orientation is 75°. The estimated response using IBR with the regional meteorological forcing is much closer to the observed values than other methods, including the classical inverted barometer correction, the dynamic atmospheric correction, the multivariable linear regression and the IBR with local forcing, demonstrating that IBR with regional forcing have the best skill in estimating the response. The large deviations between the observed values and the estimated values using IBR with the regional meteorological forcing are mainly due to the remote wind, which is not considered in the IBR. This case study indicates that the IBR is a feasible and relatively effective method to estimate the response of the coastal ocean to the meteorological forcing.
Relative timing of uplift along the Zagros Mountain Front Flexure (Kurdistan Region of Iraq): Constrained by geomorphic indices and landscape evolution modeling
Authors: Zebari Mjahid , Grützner Christoph , Navabpour Payman , Ustaszewski Kamil
Published: May 2019

Abstract. The Mountain Front Flexure marks a dominant topographic step in the frontal
part of the Zagros Fold–Thrust Belt. It is characterized by numerous active
anticlines atop of a basement fault. So far, little is known about the
relative activity of the anticlines, about their evolution, or about how
crustal deformation migrates over time. We assessed the relative landscape
maturity of three along-strike anticlines (from SE to NW: Harir, Perat, and
Akre) located on the hanging wall of the Mountain Front Flexure in the
Kurdistan Region of Iraq to identify the most active structures and to gain
insights into the evolution of the fold–thrust belt. Landscape maturity was
evaluated using geomorphic indices such as hypsometric curves, hypsometric
integral, surface roughness, and surface index. Subsequently, numerical
landscape evolution models were run to estimate the relative time difference
between the onset of growth of the anticlines, using the present-day
topography of the Harir Anticline as a base model. A stream power equation
was used to introduce fluvial erosion, and a hillslope diffusion equation was
applied to account for colluvial sediment transport. For different time steps
of model evolution, we calculated the geomorphic indices generated from the
base model. While Akre Anticline shows deeply incised valleys and advanced
erosion, Harir and Perat anticlines have relatively smoother surfaces and are
supposedly younger than the Akre Anticline. The landscape maturity level
decreases from NW to SE. A comparison of the geomorphic indices of the model
output to those of the present-day topography of Perat and Akre anticlines
revealed that it would take the Harir Anticline about 80–100 and
160–200 kyr to reach the maturity level of the Perat and Akre anticlines,
respectively, assuming erosion under constant conditions and constant rock
uplift rates along the three anticlines. Since the factors controlling
geomorphology (lithology, structural setting, and climate) are similar for
all three anticlines, and under the assumption of constant growth and erosion
conditions, we infer that uplift of the Akre Anticline started 160–200 kyr
before that of the Harir Anticline, with the Perat Anticline showing an
intermediate age. A NW-ward propagation of the Harir Anticline itself implies
that the uplift has been independent within different segments. Our method of
estimating the relative age difference can be applied to many other
anticlines in the Mountain Front Flexure region to construct a model of
temporal evolution of this belt.
A Values-based Methodology in Policing
Authors: Paulsen Jens Erik
Published: May 2019

Professional work is currently based on explicit knowledge and evidence to a greater degree than in the past. Standardising professional services in this way requires repetitive (or at least similar) scenarios and might be seen as a challenge to professional autonomy. In the context of policing, officers perform a range of familiar tasks, but they may also encounter novel challenges at any moment. Moreover, police tasks are not well-defined. Therefore, many missions require police officers to rely on common sense, tacit knowledge or gut feeling. In this article, I argue that a values-based methodology may serve as a tool to help evaluate decisions in unfamiliar situations, to learn from experience, as well as be a quality control for established routines.
Keywords:  ethics, policing, decision-making, values, experiential learningroutines.
Suspected Iatrogenic Seeding of Oral Melanoma Secondary to Endotracheal Intubation in a Dog
Authors: Lane Jeanne , Fung Canny , Gould Emily , Pfeiffer Isabella , Fasina Olufemi , Newkirk Kim
Published: May 2019

A 10 yr old castrated male pug was presented with a 3 day history of intermittent dyspnea, cough, inappetence, and inability to breathe while sleeping. He had previously received hypofractionated radiation therapy for an amelanotic oral malignant melanoma (OMM) 7 mo prior to presentation. At presentation, the dog was gasping and dyspneic. Oral examination identified the OMM on the right hard palate. Thoracic radiographs revealed an angular soft-tissue opacity within the trachea just distal to the thoracic inlet. No evidence of pulmonary metastatic disease was seen. Tracheoscopy identified a pedunculated, nonpigmented mass within the lumen of the distal trachea near the carina. Treatment options were presented to the owners and included tracheal stenting or tracheal resection and anastomosis. Because of the poor prognosis, the owners elected humane euthanasia. Postmortem examination confirmed the presence of melanoma in the distal trachea; no other sites of OMM metastasis were identified. The cause of OMM development in the distal trachea in this case is suspected to have resulted from mechanical tumor cell seeding during endotracheal tube placement for general anesthesia 7 mo prior to presentation. Despite the reported rarity of mechanical tumor seeding, this potential complication warrants consideration in dogs with OMM.
Radiographic Differentiation of Cranial Mediastinal Lymphomas from Thymic Epithelial Tumors in Dogs and Cats
Authors: Oura Trisha J. , Hamel Philip E. , Jennings Samuel H. , Bain Perry J. , Jennings Dennis E. , Berg John
Published: May 2019

In both dogs and cats, the most common cranial mediastinal masses (CMMs) are lymphoma and thymic epithelial tumors (TETs). Pretreatment differentiation of these tumors using fine needle aspiration or biopsy is essential because lymphomas are treated medically, whereas TETs are treated surgically. The purpose of this retrospective study was to determine whether thoracic radiographic findings can be used to aid clinicians in preliminarily differentiating the two tumor types before cytology or histopathology results become available. Medical records, available cytologic or histologic samples, and thoracic radiographs were evaluated for 62 dogs and 28 cats. Seventeen radiographic criteria were assessed by two examiners, and regression modeling was performed to test for significant predictors of tumor type. In dogs, CMMs with at least two well-defined radiographic margins on a lateral view and CMMs causing a rightward shift of the cardiac silhouette on a ventrodorsal or dorsoventral view were significantly more likely to be TETs than lymphomas (P < .001 and P < .01, respectively). No significant predictive variables were identified in cats. Radiographic findings do not eliminate the need for invasive sampling, but in dogs, they may guide the clinician in providing preliminary information to owners regarding the staging and therapeutic measures that may eventually be recommended.
Ligament Laxity in Nonerosive Immune-Mediated Polyarthritis in Dogs: Five Cases (2009–2017)
Authors: Whitworth Fiona , Adamantos Sophie , Frowde Polly , Whitelock Richard , Black Vicki L.
Published: May 2019

Ligament laxity is a known complication of erosive immune-mediated polyarthritis (IMPA) in dogs. The purpose of this study was to describe the occurrence and clinical features of carpal or tarsal ligament laxity in cases of nonerosive IMPA in dogs for the first time. Five client-owned dogs with a diagnosis of nonerosive IMPA and carpal or tarsal ligament laxity in which the influence of corticosteroids was excluded were identified. Medical records were reviewed, and data including signalment, investigative findings, and treatment regimen (e.g., surgical management) was extracted. Primary care practices were contacted to obtain follow-up, and the data was descriptively analyzed. The affected joints were either carpi and tarsi (n = 3) or carpi only (n = 2). In three cases, surgical arthrodesis was performed. Three dogs were euthanized (1 mo, 12 mo, and 5 yr) as a result of the severity of clinical signs and poor control. In the four dogs surviving >6 mo, multiple episodes of relapse were recorded, and multimodal immunosuppression was needed. The prognosis for the dogs described was poor, with none achieving control of the disease without ongoing immunosuppressive therapy. Damage to soft-tissue periarticular structures may be related to prolonged clinical disease or a more severe presentation. Jaccoud’s arthropathy in humans with systemic lupus erythematosus may represent a homologous presentation.
Reviewer Acknowledgements for Engineering Management Research, Vol. 8, No. 1
Authors: Taylor Cathy
Published: May 2019

Reviewer acknowledgements for Engineering Management Research, Vol. 8, No. 1, 2019
Constitutional Resilience and Unamendability
Authors: Contiades Xenophon , Fotiadou Alkmene
Published: May 2019

Constitutional Resilience and Unamendability: Amendment Powers as Mechanisms of Constitutional Resilience

This article aims to explore the relationship between unamendability and constitutional resilience. Inspired by Roznai’s theory on the limits of amendment powers, this article seeks to examine how such limits may function as a mechanism of constitutional resilience exploring how unamendability may impact the resilience of a constitution, allowing it to withstand crises while retaining its core functions. The key question is whether entrenchment enhances resilience through its protective shield or, by contrast, fetters resilience by foreclosing adaptability – what does not bend often breaks. The complex relationship between unamendability and constitutional resilience unfolds in the context of different amendment patterns.
Transitional Constitutional Unamendability?
Authors: Halmai Gábor
Published: May 2019

Transitional Constitutional Unamendability?

This article discusses the pros and cons for a suggestion to use unamendable provisions in transitional constitutions to protect the integrity and identity of constitutions drafted after a democratic transition. The presumption for such a suggestion could be that most democratic constitution-making processes are elite-driven exercises in countries with no or very little constitutional culture. The article tries to answer the question, whether in such situations unamendable constitutional provisions can help to entrench basic principles and values of constitutionalism with the help of constitutional courts reviewing amendments aimed at violating the core of constitutionalism. The article investigates the experiences of some backsliding constitutional democracies, especially Hungary, and raises the question, whether unamendable constitutional provision could have prevented the decline of constitutionalism.

In order to discuss the issue of transitional unamendability, the article engages in the scholarly discussion on transitional constitutionalism in general, and deals with the relationship of constitutional law and constitutional culture. Another side topic of the article is whether such transitional unamendability provisions should also contain international or transnational values and principles, and what happens if those are not in conformity with the unamendable provisions that serve to build up a national constitutional identity. Again, the example of Hungary can be important here, how national constitutional identity protected by the Constitutional Court can serve to abandon the European constitutional whole.