bluuebunny/crossref_metadata_2025 huggingface dataset:
X-Ray Structural Studies of Small-Bite Ligands on Large Cations – Lanthanide(III) Ions and Dimethylphosphate
Authors: Chan Eric J. , Harrowfield Jack M. , Skelton Brian W. , White Allan H.
Published: December 2019

Reactions of lanthanide chlorides or trifluoracetates (tfa) or picrates with trimethylphosphate alone in the first two cases or trimethylphosphate plus 1,10-phenanthroline or 2,2′;6′,2′′-terpyridine in the third, result in the formation of crystalline products containing dimethylphosphate (dmp–). Single crystal X-ray structural characterisation of these materials has shown that the stoichiometrically simple Ln(dmp)3 species obtained with chloride reactants and the lighter lanthanides are polymeric and commonly dimorphic, while the stoichiometrically more variable mixed dmp/tfa complexes have structures closely related to one phase of the Ln(dmp)3 family, and the presence of picrate and aza-aromatic ligands enables the isolation of Y and Lu derivatives containing binuclear species. In all, the dmp– ligands adopt exclusively the κ1O;κ1O′ bridging mode, the overall results indicating that this should apply to the complete lanthanide series.
Desert bighorn sheep responses to human activity in south-eastern Utah
Authors: Sproat Kanalu K. , Martinez Nathan R. , Smith Tom S. , Sloan William B. , Flinders Jerran T. , Bates J. William , Cresto Joseph G. , Bleich Vernon C.
Published: December 2019

Abstract ContextHuman activity in wildlands can influence wildlife populations by decreasing or degrading habitat, decreasing survival, or through displacement. For bighorn sheep (Ovis canadensis), some human activities are detrimental and may result in physiological stress, altered activity budgets, or habitat abandonment. From 1979 to 2000, human recreation increased over 300% in areas occupied by desert bighorn sheep (O. c. nelsoni) in south-eastern Utah. Concurrently, the population of desert bighorn sheep occupying the Potash Bighorn Sheep Management Unit of south-eastern Utah was in steep decline. AimsWe investigated behavioural responses of desert bighorn sheep to different levels of human activity in this area from 2002 to 2003. MethodsWe divided the study population into two areas on the basis of the level of human use, i.e. low and high. We observed desert bighorn sheep at seven sites within these areas, including three with a high level of human use and four areas of a low level of human use. Key resultsDesert bighorn sheep spent significantly less time grazing and more time vigilant in areas of a high level of human use than in areas of a low level of human use. ConclusionsHuman recreational use of desert bighorn sheep habitat has the potential to negatively affect foraging by desert bighorn sheep. ImplicationsWe raise a cautionary flag because recreational use in bighorn sheep habitat near Moab, Utah, continues to increase and bighorn numbers continue to decline. When managers consider proposals to increase areas or trails for human recreation, they should incorporate ways to minimise impacts and reduce stressors to bighorn sheep.
Physiological stress response of African elephants to wildlife tourism in Madikwe Game Reserve, South Africa
Authors: Szott Isabelle D. , Pretorius Yolanda , Ganswindt Andre , Koyama Nicola F.
Published: December 2019

Abstract ContextWildlife tourism has been shown to increase stress in a variety of species and can negatively affect survival, reproduction, welfare, and behaviour of individuals. In African elephants, Loxodonta africana, increased physiological stress has been linked to use of refugia, rapid movement through corridors, and heightened aggression towards humans. However, we are unaware of any studies assessing the impact of tourism pressure (tourist numbers) on physiological stress in elephants. AimsWe used faecal glucocorticoid metabolite (fGCM) concentrations to investigate whether tourist numbers in Madikwe Game Reserve, South Africa, were related to changes in physiological stress in elephants. MethodsWe repeatedly collected dung samples (n=43) from 13 individually identified elephants over 15 months. Using a generalised linear mixed model and a Kenward–Roger approximation, we assessed the impact of monthly tourist numbers, season, age, and sex on elephant fGCM concentrations. Key resultsHigh tourist numbers were significantly related to elevated fGCM concentrations. Overall, fGCM concentrations increased by 112% (from 0.26 to 0.55µgg−1 dry weight) in the months with the highest tourist pressure, compared to months with the lowest tourist pressure. ConclusionsManagers of fenced reserves should consider providing potential alleviation measures for elephants during high tourist pressure, for example, by ensuring that refuge areas are available. This may be of even higher importance if elephant populations have had traumatic experiences with humans in the past, such as poaching or translocation. Such management action will improve elephant welfare and increase tourist safety. ImplicationsAlthough tourism can generate substantial revenue to support conservation action, careful monitoring of its impact on wildlife is required to manage potential negative effects.
Development of the method of production of the ultrafine macrohomogeneous composite powder
Authors: Mestvirishvili Zviadi , Kvatchadze Vakhtang , Bairamashvili Irakli , Jalabadze Nikoloz , Mestvirishvili Tornike
Published: December 2019

A method of ultrafine macro-homogeneous composite powder – B4C–ZrO2 production using a planetary mill was developed. From the macro-homogeneous composite high-density ceramics, B4C–ZrB2 was produced by the method of reactive sintering (in situ) at 2000°C under the pressure of 41–42 MPa. The effect of ZrO2 grain size and of its distribution in the matrix on the consolidation parameters, and the microstructure of the obtained ceramics was studied.
Characteristic analysis of the fermentation and sporulation properties of the traditional sake yeast strain Hiroshima no.6
Authors: Yamasaki Risa , Goshima Tetsuya , Oba Kenji , Isogai Atsuko , Ohdoi Ritsushi , Hirata Dai , Akao Takeshi
Published: December 2019

General sake yeasts (e.g., Kyokai no.7, K7) show high fermentation ability and low sporulation frequency. Former is related to stress-response defect due to the loss-of-function of MSN4 and RIM15. Later is mainly caused by low IME1 expression, leading to difficulty in breeding and genetic analysis. Sake yeast Hiroshima no.6 (H6), which had been applied for sake fermentation, has sporulation ability. However, its detailed properties have not been unveiled. Here we present that the fermentation ability of H6 is suitable for sake brewing, and the precursor of dimethyl trisulfide in sake from H6 is low. MSN4 but not RIM15 of H6 has the same mutation as K7. Our phylogenetic analysis indicated that H6 is closely related to the K7 group. Unlike K7, H6 showed normal sporulation frequency in a partially RIM15-dependent manner, and IME1 in H6 was expressed. H6 possesses excellent properties as a partner strain for breeding by crossing.
Deep-ultraviolet integrated photonic and optoelectronic devices: A prospect of the hybridization of group III–nitrides, III–oxides, and two-dimensional materials
Authors: Alfaraj Nasir , Min Jung-Wook , Kang Chun Hong , Alatawi Abdullah A. , Priante Davide , Subedi Ram Chandra , Tangi Malleswararao , Ng Tien Khee , Ooi Boon S.
Published: December 2019

Progress in the design and fabrication of ultraviolet and deep-ultraviolet group III–nitride optoelectronic devices, based on aluminum gallium nitride and boron nitride and their alloys, and the heterogeneous integration with two-dimensional and oxide-based materials is reviewed. We emphasize wide-bandgap nitride compound semiconductors (i.e., (B, Al, Ga)N) as the deep-ultraviolet materials of interest, and two-dimensional materials, namely graphene, two-dimensional boron nitride, and two-dimensional transition metal dichalcogenides, along with gallium oxide, as the hybrid integrated materials. We examine their crystallographic properties and elaborate on the challenges that hinder the realization of efficient and reliable ultraviolet and deep-ultraviolet devices. In this article we provide an overview of aluminum nitride, sapphire, and gallium oxide as platforms for deep-ultraviolet optoelectronic devices, in which we criticize the status of sapphire as a platform for efficient deep-ultraviolet devices and detail advancements in device growth and fabrication on aluminum nitride and gallium oxide substrates. A critical review of the current status of deep-ultraviolet light emission and detection materials and devices is provided.
Recent progress of SiC UV single photon counting avalanche photodiodes
Authors: Su Linlin , Zhou Dong , Lu Hai , Zhang Rong , Zheng Youdou
Published: December 2019

4H-SiC single photon counting avalanche photodiodes (SPADs) are prior devices for weak ultraviolet (UV) signal detection with the advantages of small size, low leakage current, high avalanche multiplication gain, and high quantum efficiency, which benefit from the large bandgap energy, high carrier drift velocity and excellent physical stability of 4H-SiC semiconductor material. UV detectors are widely used in many key applications, such as missile plume detection, corona discharge, UV astronomy, and biological and chemical agent detection. In this paper, we will describe basic concepts and review recent results on device design, process development, and basic characterizations of 4H-SiC avalanche photodiodes. Several promising device structures and uniformity of avalanche multiplication are discussed, which are important for achieving high performance of 4H-SiC UV SPADs.
Hot electron effects on the operation of potential well barrier diodes
Authors: Akura M. , Dunn G. , Missous M.
Published: December 2019

A study has just been carried out on hot electron effects in GaAs/Al0.3Ga0.7As potential well barrier (PWB) diodes using both Monte Carlo (MC) and drift-diffusion (DD) models of charge transport. We show the operation and behaviour of the diode in terms of electric field, mean electron velocity and potential, mean energy of electrons and Γ-valley population. The MC model predicts lower currents flowing through the diode due to back scattering at anode (collector) and carrier heating at higher bias. At a bias of 1.0 V, the current density obtained from experimental result, MC and DD simulation models are 1.35, 1.12 and 1.77 μA/μm2 respectively. The reduction in current over conventional model, is compensated to a certain extent because less charge settles in the potential well and so the barrier is slightly reduced. The DD model results in higher currents under the same bias and conditions. However, at very low bias specifically, up to 0.3 V without any carrier heating effects, the DD and MC models look pretty similar as experimental results. The significant differences observed in the I–V characteristics of the DD and MC models at higher biases confirm the importance of energy transport when considering these devices.
Selection of DBO measurement wavelength for bottom mark asymmetry based on FDTD method
Authors: Xu Buqing , Wu Qiang , Dong Lisong , Wei Yayi
Published: December 2019

A physical model for simulating overlay metrology employing diffraction based overlay (DBO) principles is built. It can help to optimize the metrology wavelength selection in DBO. Simulation result of DBO metrology with a model based on the finite-difference time-domain (FDTD) method is presented. A common case (bottom mark asymmetry) in which error signals are always induced in DBO measurement due to the process imperfection were discussed. The overlay sensitivity of the DBO measurement across the visible illumination spectrum has been performed and compared. After adjusting the model parameters compatible with the actual measurement conditions, the metrology wavelengths which provide the accuracy and robustness of DBO measurement can be optimized.
Growth properties of gallium oxide on sapphire substrate by plasma-assisted pulsed laser deposition
Authors: Hu Congyu , Saito Katsuhiko , Tanaka Tooru , Guo Qixin
Published: December 2019

Gallium oxide was deposited on a c-plane sapphire substrate by oxygen plasma-assisted pulsed laser deposition (PLD). An oxygen radical was generated by an inductive coupled plasma source and the effect of radio frequency (RF) power on growth rate was investigated. A film grown with plasma assistance showed 2.7 times faster growth rate. X-ray diffraction and Raman spectroscopy analysis showed β-Ga2O3 films grown with plasma assistance at 500 °C. The roughness of the films decreased when the RF power of plasma treatment increased. Transmittance of these films was at least 80% and showed sharp absorption edge at 250 nm which was consistent with data previously reported.
A contrivance of 277 nm DUV LD with B0.313Ga0.687N/B0.40Ga0.60N QWs and AlxGa1–xN heterojunction grown on AlN substrate
Authors: Niass Mussaab I. , Sharif Muhammad Nawaz , Wang Yifu , Lu Zhengqian , Chen Xue , Qu Yipu , Du Zhongqiu , Wang Fang , Liu Yuhuai
Published: December 2019

In this paper, an ultraviolet C-band laser diode lasing at 277 nm composed of B0.313Ga0.687N/B0.40Ga0.60N QW/QB heterostructure on Mg and Si-doped Al
x
Ga1–x
N layers was designed, as well as a lowest reported substitutional accepter and donor concentration up to N
A = 5.0 × 1017 cm–3 and N
D = 9.0 × 1016 cm–3 for deep ultraviolet lasing was achieved. The structure was assumed to be grown over bulk AlN substrate and operate under a continuous wave at room temperature. Although there is an emphasizing of the suitability for using boron nitride wide band gap in the deep ultraviolet region, there is still a shortage of investigation about the ternary BGaN in aluminum-rich AlGaN alloys. Based on the simulation, an average local gain in quantum wells of 1946 cm–1, the maximum emitted power of 2.4 W, the threshold current of 500 mA, a slope efficiency of 1.91 W/A as well as an average DC resistance for the V–I curve of (0.336 Ω) had been observed. Along with an investigation regarding different EBL, designs were included with tapered and inverse tapered structure. Therefore, it had been found a good agreement with the published results for tapered EBL design, with an overweighting for a proposed inverse tapered EBL design.
Study of the morphology evolution of AlN grown on nano-patterned sapphire substrate
Authors: Wu Zhuohui , Yan Jianchang , Guo Yanan , Zhang Liang , Lu Yi , Wei Xuecheng , Wang Junxi , Li Jinmin
Published: December 2019

This study focused on the evolution of growth front about AlN growth on nano-patterned sapphire substrate by metal-organic chemical vapor deposition. The substrate with concave cones was fabricated by nano-imprint lithography and wet etching. Two samples with different epitaxy procedures were fabricated, manifesting as two-dimensional growth mode and three-dimensional growth mode, respectively. The results showed that growth temperature deeply influenced the growth modes and thus played a critical role in the coalescence of AlN. At a relatively high temperature, the AlN epilayer was progressively coalescence and the growth mode was two-dimensional. In this case, we found that the inclined semi-polar facets arising in the process of coalescence were

type. But when decreasing the temperature, the

semi-polar facets arose, leading to inverse pyramid morphology and obtaining the three-dimensional growth mode. The 3D inverse pyramid AlN structure could be used for realizing 3D semi-polar UV-LED or facet-controlled epitaxial lateral overgrowth of AlN.
Method of stabilizing pulsating gas flows in the intake system of a piston engine with turbocharging
Authors: Plotnikov L V , Zhilkin B P , Brodov Yu M
Published: December 2019

Piston internal combustion engines (ICE) are the most common sources of energy among heat engines. Currently, most ICEs are equipped with a turbocharging system. Thermomechanical perfection of processes in the intake system largely determines the efficiency of engines. This article proposes a method of stabilizing the pulsating flows in the intake system by installing the leveling grid in the output channel of the turbocharger (TC) compressor. Studies were conducted on an experimental setup, which consisted of a single-cylinder engine and turbocharging system. A constant-temperature thermo-anemometer was used to determine the instantaneous values of the air flow rate and the local heat transfer coefficient. It has been established that the presence of a leveling grid in the intake system leads to a decrease in the turbulence number by up to 25% compared with the basic intake system (while maintaining the flow characteristics). It is shown that the installation of a leveling grid in the intake system of the ICE with TC also leads to a decrease in the heat transfer intensity by up to 15 % compared to the base system. The obtained data expands the knowledge base on the thermomechanics of pulsating flows in hydraulic systems of complex configuration.
Spectral methods in physical and chemical measurements
Authors: Muravskaya N P
Published: December 2019

The paper presents the spectral methods used in high-precision physico-chemical measurements.
The potential of inductively coupled plasma mass spectrometry for measuring the isotopic composition of elements
Authors: Kremleva Olga N , Tabatchikova Tatyana N
Published: December 2019

Brief information about the development of enriched isotopic composition reference materials (RMs) is presented. The potential of inductively coupled plasma mass spectrometry for measuring the isotopic composition of elements are shown.
Determination of colloidal nanoparticle parameters
Authors: Belenkii D I , Magomedov T M , Balakhanov D M
Published: December 2019

The paper describes number concentration of colloidal nanoparticles measurement methods and principles. Results additional measurements of particle sizes and zeta potential are presented. Conclusions are drawn about the possibility of using this method for characterization of the reference materials.
Development of reference methods of measurements mass (molar) concentration of proteins in the field of physical and chemical analysis of blood
Authors: Griazskikh N Y , Ivanov A V , Muravskaya N P
Published: December 2019

The work is devoted to the development of reference methods for measuring the mass concentration of proteins in blood plasma that would meet modern metrological requirements (high accuracy of reference values, metrological traceability, etc.), which will allow the use of modern high-tech methods of physicochemical analysis.
Special measures of radionuclides activity to metrological support of measurements in radiation control
Authors: Dyachkova V , Zotova M , Tonkih N
Published: December 2019

The possibilities of FSUE VNIIFTRI for production and calibrating special measures of activity (imitants of radioactive contamination of environmental objects) are presented. A description of the measures of activity with different geometries and materials for the calibration of spectrometric, radiometric and aerosol equipment is given. The importance and practical importance of the production of these imitants is determined by the fact that they are widely used for metrological support of radiometric and spectrometric measuring instruments because it make it possible to calibrate the measuring instruments for conditions that are closest to the real ones, thereby reducing the error of the measurement results.
Development of a conductivity sensor for measuring conductivity of ultrapure water
Authors: Smirnov A M , Chernikov I G
Published: December 2019

The work is devoted to the research results of the developed piston conductivity cell, equipped with additional «guard» electrodes for equipotential protection. Cell able to work both in flow and in static measurement mode.
Perfecting technology for producing thermistors at VNIIFTRI
Authors: Priadka A.A
Published: December 2019

In this work characteristics of the thermistors, created by the method developed in VNIIFTRI were investigated. Parameters of thermistors are studied, dependences of their properties on manufacturing techniques are revealed.
Light Air Ions Generators and Air Ion Concentration Working Standards
Authors: Nechaev N , Kolersky S , Zubkov P
Published: December 2019

The article describes the requirements for air ion generators used in air ion concentration working standards and gives the results of the tests of air ion generators designed in accordance with these requirements.
About the development of reference materials of meat and meat product composition
Authors: Medvedevskikh M Yu , Sergeeva A S , Krasheninina M P , Vostrikova N L , Semenova A A , Kuznetsova O A
Published: December 2019

The paper describes the development of certified reference materials (CRM) of meat and meat product composition
Development of reference materials with the composition of propyl and isopropyl alcohol solutions
Authors: Piterskikh I A , Vikhrova S V , Rutenberg O L , Kovaleva N G , Barinskaya T O
Published: December 2019

In this work the development of RMs of mass concetration of the main components (propanol-1 and propanol-2) in biological objects (urine, blood) are described.
The Role of Distributions and Control Charts in Metrology
Authors: Adler Yu , Polkhovskja T , Filichkina V , Shper V
Published: December 2019

In this paper it is suggested to change radically the existing metrology paradigm for measurement data analysis, namely to reject from searching the appropriate Distribution Function (DF) and use nonparametric methods for uncertainty estimation in all circumstances. This let to avoid using limiting and unprovable assumptions that lead to invalid conclusions. In the paper it is offered to use Shewhart Control Charts (ShCC) as an indispensable method to monitor the current state of measurement system. And this method does not require any assumptions about specific type of DF.
Capabilities of VNIIIFTRI in the field of measurements of meteorological parameters
Authors: Justus N M , Dobrovolskiy V I , Dobrovolskiy K I
Published: December 2019

The creation of new working standards at the All-Russian Scientific Research Institute of Physicotechnical and Radio Engineering Measurements (VNIIFTRI) for metrological support of meteorological measuring instruments is mentioned in the work.
Climatological and land use evaluation to maintain water supply in Pulai reservoir, Bintan island - Indonesia
Authors: Fakhrudin M. , Subehi Luki , Wibowo Hendro
Published: December 2019

Pulai reservoir with an area of 49.9 ha and maximum depth of 12 m, serves as clean water resources for Tanjung Pinang city, Bintan island. The objective of this research was to evaluate the fluctuation of water level on reservoir, related to the climatological and land use conditions. Water level in January 2009 was 400 cm and continued to decrease to 105 cm in August 2009 that ceased the water supply. The rainfall during ten months study period (January – October 2009) was 1,968 mm, below of its average level of 2,447 mm. The dry spell reduced the water supply input to reservoir for about 2.5 million m3 or equivalent to four months of clean water supply. Mean monthly air temperature was also increased by 1 °C compared to the last 29 years. A similar trend was observed for humidity, where its mean value of 85.9% decreased to 83.3%. Initially, the catchment area was 474.12 ha, covered by protected forest (98%). However, in 2009 the remaining forest area was only 8.15%. It suggested the decreasing of water storage capacity. It could be explained that the climate change and uncontrolled land use may contribute to the water crisis of Pulai reservoir.
Dissolved oxygen and temperature stratification analysis for early warning system development in preventing mass mortality of fish in lake Maninjau, West Sumatera - Indonesia
Authors: Fakhrudin M. , Subehi Luki , Jasalesmana Taofik , Dianto Aan
Published: December 2019

Lake Maninjau is caldera lake which lies at Sumatera island, Indonesia. The objective of this paper is to analyse dissolved oxygen (DO) and water temperature (WT) stratification related to mass mortality fish. The WT and DO stratification were measured by logger version CTD profiler with a depth interval of 1 m in March 2018. Based on analysis at 12 stations of measurement from buoyancy frequency value showed various stratification. The top layer (epilimnion) had a thickness of 2 m and the concentration of DO was 4.8 mg/l – 13.5 mg/l. Meanwhile, the hypolimnion layer formed at various depths ranged from 9-20 m to the bottom of the lake with concentration of DO was close to zero. These two layers are separated by a thermocline (metalimnion), which acted as a buffer. When the surface temperature of the lake was cooler than the lower one, then the density was increased, the turnover occurred. Then, the concentration of DO at the upper layer of the lake decreased, caused mass mortality fish. The process of the mass water reversal was monitored through temperature stratification and DO measurements in real time, as criterion for early warning system of mass mortality of fish.
Phytoplankton composition and the occurrence of cyanobacterial bloom in Lake Maninjau, Indonesia
Authors: Sulastri  , Henny C , Santoso A B
Published: December 2019

Algae blooms have been recorded in Lake Maninjau in November 2000, October 2011 and recently on April 2018. These blooms were indicated by green scum formation on the lake surface with a very high chlorophyll-a concentration, as high as > 100 µg-L. We determined the characteristics of phytoplankton composition and abundance including environmental conditions during cyanobacterial blooms and non-cyanobacterial blooms in Lake Maninjau. During cyanobacterial blooms, phytoplankton were dominated by Microcystis aeruginosa with a maximum abundance of 24,320 x 103 individual L-1 (94.4 % of the total assemblage). While during the non-blooming period, cyanobacteria species were more diverse, represented by Cylindrospermopsis raciborskii, Anabaea affinis, Aphanizomeon sp, Planktolyngbya sp. and Chroococcus sp. Diatom (Synedra ulna) generally occurred in all conditions, however, desmids (green algae) disappeared during cyanobacteria blooms. It is highlighted that the occurrence of Microcystis blooms can be related to total phosphorous dynamics in the lake.
Bioaccumulation of Lead (Pb) in the macroalgae Padina australis Hauck in Makassar Marine Waters, South Sulawesi, Indonesia
Authors: Supardi Wahyu , Puspito Nugroho Andhika
Published: December 2019

Marine pollution is a global problem that occurs in coastal areas. Pb lead pollutants derived from waste discharges and Makassar community activities can accumulate on the macroalgae Padina australis Hauck. This study determined the accumulation of Pb on P. australis and assessed the abundance of P. australis in three stations in Makassar marine waters of Lae-lae, Samalona and Barranglompo from November-April 2018. Sampling P. australis was done by purposive sampling method. Data of P. australis abundance was taken using the line transect method. Physico-chemical parameters measured were temperature, salinity, pH, light penetration, current, DO, and BOD. Pb analysis was done using the Atomic Absorption Spectrophotometer. The results showed difference of Pb content in P. australis was found from each research station. The content of Pb at Station I is in the range of 0.0964-0.1388 ppm, Station II 0.0496-0.1050 ppm, and station III 0.0597-0.1035 ppm which has exceeded the water limit specified (> 0.008) ppm. The average concentration of Pb at station I was compared to other stations because Station I was closer to the mainland, with potentially greater entry of heavy metal Pb. Abundance of P. australis at station I were 92 ind/m2, station II 152 ind/m2 and station III were 319 ind/m2. Correlation analysis data showed no significant value (ρ = 0.384, p > 0.05) which meant that the Pb concentration did not affect P. australis abundance.
Experimental evidence of monolayer arsenene: an exotic 2D semiconducting material
Authors: Shah J , Wang W , Sohail H M , Uhrberg R I G
Published: December 2019

Group V element analogues of graphene have attracted a lot of attention recently due to their semiconducting band structures and several other interesting properties predicted by theoretical investigations in the literature. In this study, we present atomic and electronic structure data of an arsenic (As) layer on Ag(1 1 1). Low-energy electron diffraction and scanning tunneling microscopy data provide evidence for an ordered layer with a lattice constant of 3.6 Å. This value fits with the theoretical range of 3.54–3.64 Å for buckled arsenene, which is the structure consistently predicted by various theoretical studies. The electronic structure obtained by angle-resolved photoelectron spectroscopy shows the existence of three 2D electron bands within 4 eV below the Fermi level. The number of bands and the agreement between experimental band dispersions and the theoretical band structure provide further evidence for the formation of monolayer buckled arsenene on Ag(1 1 1).
Influence of ultrasonication power on grain refinement, mechanical properties and wear behaviour of AZ91D/nano-Al2O3 composites
Authors: Gnanavelbabu A , Sunu Surendran K T , Kumar S
Published: December 2019

In this study, magnesium alloy (AZ91D) matrix composites reinforced with 1 wt% of nano alumina (n-Al2O3) were fabricated using novel Ultrasonic Treatment (UST) assisted squeeze casting method. UST was carried out at four different levels of ultrasonic power namely, 0 W (without UST), 1500 W, 2000 W and 2500 W at constant frequency and time. The composites were heat-treated at T6 condition under argon gas protected environment. Microstructural analysis was done using optical microscopy and high-resolution scanning electron microscopy. Physical, mechanical and tribological properties of the composites were evaluated. A significant refinement in grain structure and improvement in porosity was seen on an increase in UST power. Improvement was seen in micro-hardness, yield strength, ultimate tensile strength and % of elongation of the composite fabricated at 2500 W by 18%, 48%, 28%, and 10% respectively compared to an untreated composite. The composite fabricated at 2500 W showed less wear rate and coefficient of friction when compared to other composites at all sliding conditions. Scanning electron microscope images of the worn surface of the composite pins revealed that the wear mechanisms dominated were abrasion, adhesion, oxidation and delamination.
Microstructural analysis of weld nugget properties on resistance spot-welded advance high strength dual phase (α+α/) steel joints
Authors: Rajarajan C , Sivaraj P , Balasubramanian V
Published: December 2019

This research work focuses on production of sound weld by Resistance Spot Welding (RSW) process and correlate the mechanical properties of Dual Phase (DP) steel joints with its microstructural features. The main application of resistance spot welding was used to build white body assembly in automotive industry. The welded joint recorded maximum value of 21.3 kN in TSFL and 18.3 kN in CTSFL. The Scanning Electron Microscope (SEM) and Optical Microscope (OM) of the Nugget Zone (NZ) revealed lath/needle like microstructures with effect of severe cooling rate. The TEM microstructure exposed the formation of martensite (α
/) in the Nugget Zone (NZ) and tempered martensite (Tα
/) in Heat Affected Zone (HAZ), which accounts for superior joint strength of DP lap shear joints. Furthermore, crystallography studies reported the phase composition and crystallinity in weldments as cementite and magnesium carbide in [101] and [200] indices that accounts for high hardness of 584 Hv in the weldments.
The US–Mexico War and American Literary History
Authors: Rodríguez Jaime Javier
Published: December 2019

The US–Mexico War produced a wide range of literature in the United States that exposed the provisional and contingent qualities of US nationalism, even while it also asserted the anti-Mexican racism and xenophobia that continues to shape cultural and political discourse in the early 21st century. Much of the popular literature produced in mass-market novelette form, for example, deployed a range of Mexican enemies that ran through a sequence from noble, chivalrous opponents, to fiendish enemies and terrorist bandits. This instability in how writers saw Mexico and Mexicans suggests that the war could paradoxically generate critical self-reflections that countered essentialist notions of manifest destiny. The eventual projection of the bandit figure as the prototypical Mexican villain reinforced Anglo-American national self-definitions of moral, cultural, and racial superiority as a response to the destabilizing energies resulting from the invasion of a neighboring American republic. For Mexican American writers, the war, although a major feature of Mexican American literature, nonetheless became an environment in which to explore conditions of non-national, liminal border identities, which became strikingly relevant as the 20th century turned into the 21st. In Mexico, the agonized response to the nation’s failure to stop the “Yankee” invader led instead to a confrontation with its own lack of a unifying national identity and forced writers and political intellectuals to ask hard questions about Mexico’s destiny.
From Nationalist Movements to Transnational Solidarities: Comparative and Pan-Latina/o Literary Studies
Authors: Caminero-Santangelo Marta
Published: December 2019

While literature by Latin American origin groups within the United States (e.g., Mexican, Puerto Rican, Cuban, Dominican) has been treated as a single literary corpus—“Latina/o Literature” or “Hispanic Literature”—since the last decades of the 20th century, in practice, the commonalities among such texts were more comparative than panethnic in nature until significantly more recently. That is, while literature by different national-origin groups revealed some strong similarities in theme and form, the writing itself reflected the specific concerns, background, and history of the specific national-origin group, rather than giving evidence of intra-Latino group interaction or a developing sense of a shared intra-Latino culture. This essay traces the commonalities among these bodies of literary production, including in the “pre-Latino” period, the 19th to mid-20th centuries, before there was even a commonly understood concept of “US Latino literature,” as well as during the Chicano and Nuyorican Movements of the 1960s and 1970s. It then turns to a discussion of developing representations of inter-group interactions and tensions, including in the more recent emergence of “Central American American” literary production. Particularly in the increasingly cosmopolitan urban centers of the United States, an evolving sense of intra-Latino solidarity and panethnic Latino “community” has come into view in the literature produced by Latinx writers of the later 20th and 21st centuries.
Advances in Team Creativity Research
Authors: Gilson Lucy L. , Lee Yuna S. H. , Litchfield Robert C.
Published: December 2019

Although creativity research has historically focused on individuals, with more and more employees working in teams, researchers have started to explore the construct of team creativity. Rather than a comprehensive review, this article takes an in-depth look at the most recent team creativity research. To do this, key themes and trends are discussed, which are then tied back to prior reviews, and new avenues for future research are proposed. Team creativity is a challenging construct because it can be conceptualized as both an outcome and a process, and there is no clear definition of either. When considering team creativity as an outcome, research has employed both complex mediation models as well as a more nuanced examination of moderating variables and constructs that may strengthen or attenuate the effects of relationships related to team creativity. This growing avenue of research recognizes the variability in team creativity that is possible in different circumstances and contexts, and seeks to identify what drives different outcomes. These approaches also acknowledge that team creativity is not guaranteed even when enabling conditions are in place, and that other variables may exert forces in different ways.

The recognition that team creativity is unlikely to be the simple sum of members’ creative processes is becoming very apparent, with researchers examining ways of encouraging, fostering, and sustaining creativity in teams over time. Researchers have also recognized that team creativity is more likely to unfurl over time as a process, rather than a discrete point-in-time event. To this end, the key areas examined are the roles of member diversity and leadership. For diversity, racio-ethno, cultural, gender, age, political orientation, and diversity training have all been examined. For leadership, the focus has shifted away from the more traditional transformational theories and to newer constructs such as humility, ethical and shared leadership, as well as what it means to have an ideational leader who facilitates idea generation. Taken together, what the most recent research tells us is that creativity in teams remains a growing and evolving area of inquiry. While no longer unexplored, much remains to be clarified such as the barriers to effective team creativity, and practices that may help transcend these barriers. A lot of promising areas for future research are highlighted, which will become more important as workplaces pivot toward cultivating team creativity in a systematic and intentional way.
From Decision Making to Decision Support
Authors: Adam Frederic
Published: December 2019

In such a complex and well-researched domain as decision support systems (DSS), with a long history of authors making insightful contributions since the 1960’s, it is critical for researchers, especially those less experienced, to have a broad knowledge of the seminal work that has been carried out by prior generations of researchers. This can serve to avoid proposing research questions which have been considered many times before, without having consideration for the answers which have been put forward by previous scholars, thereby reinventing the wheel or “rediscovering” findings about the life of organizations that have been presented long before. The study of human and managerial decision-making is also characterized by considerable depth and seminal research going back to the beginning of the 20th century, across a variety of fields of research including psychology, social psychology, sociology or indeed operations research. Inasmuch as decision-making and decision support are inextricably linked, it is essential for researchers in DSS to be very familiar with both stream of research in their full diversity so they are able to understand both what activity is being supported and how to analyze requirements for developing decision support artefacts. In addition, whilst the area of decision support has sometimes been characterized by technology-based hype, it is critical to recognize that only a clear focus on the thinking and actions of managers can provide decisive directions for research on their decision support needs. In this article, we consider first the characteristics of human cognition, before concentrating on the decision-making needs of managers and the lessons that can be derived for the development of DSS.
Collective Memory and Journalism
Authors: Bosch Tanja
Published: December 2019

The relationship between the practice and field of journalism and the interdisciplinary field of memory studies is complex and multifaceted. There is a strong link between collective memory production and journalistic practice, based on the proposition that journalists produce first drafts of history by using the past in their reportage. Moreover, the practice of journalism is a key agent of memory work because it serves as one of society’s main mechanisms for recording and remembering, and in doing so helps shape collective memory. Journalism can be seen as a memory text, with journalists constructing news within cultural-interpretive frames according to the cultural environment. Journalism also plays a key role in the production of visual memory and new media, including social media. Journalism is thus a key agent of memory work, providing a space for commentary on institutional and cultural sites of memory construction.
The Politics of Cost–Benefit Analysis
Authors: Mouter Niek
Published: December 2019

Cost–benefit analysis (CBA) is a widely used economic appraisal method that aims to support politicians in making decisions about projects and policies. Several researchers have tried to uncover the extent to which CBA actually impacts decision-making by investigating the statistical relation between the results of CBA studies and political decisions. Although these studies show that there is no significant statistical relation between the outcomes of CBA studies and political decisions, there is clear evidence that the institutionalization of CBA affects the planning and decision-making process within the bureaucracy. Civil servants, for instance, use CBAs to government projects in the early phases of the planning process. The literature identifies various barriers that hamper politicians’ use of CBA when forming their opinion. First, politicians often receive results of CBA studies too late in the process. When politicians receive a CBA after they already made up their mind and communicated their viewpoint, the chance is low that the results of the CBA will (substantially) influence their decision. A second important barrier that limits the use of CBA by politicians is that they do not have enough trust in CBA’s impartiality. A third barrier is that politicians contest value judgments implicit in CBA.

The literature distinguishes six ideological value judgments that inevitably need to be made when conducting a CBA: (a) Which individuals have standing in a CBA? (b) Which preferences have standing in a CBA? (c) Which procedure is used to value impacts? (d) On which dimensions are standard numbers differentiated? (e) Which weight is assigned to preferences of individuals in the social welfare function? (f) Which approach is adopted to select the social discount rate? The implication of the fact that CBA analysts cannot escape from making value judgments when conducing the study is that CBA is currently a problematic tool for democratic decision-making because, when applied in practice, the analysis is based on a specific set of politically loaded premises that foster (damage) the interests of politicians (not) endorsing these premises. It is possible to overcome this problem through informing politicians about the extent to which switching value judgements leads to different CBA outcomes. The introduction of so-called normative sensitivity analyses safeguards that politicians with different belief systems are equally equipped to use the results of a CBA to arrive at a well-founded evaluation of a government project.
The Availability Heuristic, Political Leaders, and Decision Making
Authors: Cohen Michael
Published: December 2019

The cognitive and emotional mechanics of the human brain have profound effects on when and what people and political leaders learn, and this can have significant effects on their causal beliefs, preferences, and policies. The existence of the availability heuristic and its biasing effects on political judgment is one of the most robust findings from decades of research in cognitive psychology. The core mechanism involves people being more likely to learn from the phenomena that are most easily recalled by memory, which tend to be dramatic and vivid events, rather than other, often more normatively probative sources. Most applications of this insight to foreign policy decision-making also tend to assume that an actor’s personal experiences will impact what tends to be more or less easily recalled and thus better predict who learns which lesson from which event. This heuristic enables leaders to deal with the vast amount of extant information but also can cause systematic biases in causal inference.

Documenting the availability heuristic and its effects on political decision-making requires (usually archival) data on leaders beliefs’ over long periods of time, from their formative political lessons through decisions and nondecisions when in power, in order to reliably clarify which lessons were in fact learned, when and why a leader learned which lesson from what data point, why that data point happened to be cognitively available, and whether these lessons influenced policy. Ideally, studies should also assess these leaders’ associates where possible to determine whether they learned similar lessons from the same events. Studies can also apply statistical analysis to larger populations of leaders who are likely to have found different events cognitively available. This article focusses on decisions in the realm of foreign policy and international security, although availability certainly plays a role in other domains as well. Decades of scholarship have now shown the relevance of the availability heuristic in U.S., Soviet, Indian, Chinese, and Pakistani grand strategy and foreign policy, approaches to nuclear weapons, and extant alliances and threat perceptions. But much work remains to be done in these cases and elsewhere, as well as in other fields like international political economy and comparative politics.
Immigration Policy and European Union Politics
Authors: Zaun Natascha , Roos Christof
Published: December 2019

EU immigration policies have incrementally evolved from a purely intergovernmental to a deeply integrated EU policy area. In practice, EU immigration policies and EU secondary legislation still leave significant discretion to the Member States, as witnessed by key developments in the various subfields of immigration policies—including policies on border protection, return and irregular migration, as well as labor migration and family migration policies. The key academic debates on EU immigration policies have mainly focused on explaining the decision-making processes behind the adoption of EU policies as well as their impact on national policies. While scholars find that these EU policies have led to liberalizations in the areas of family migration or labor migration, the irregular migration and border policies of the EU have gradually produced more restrictive outcomes. Policy liberalizations are usually based on the impact of EU institutions, which tend to have more liberal positions than Member States. Lowest common denominator output at the EU level, such as on the Blue Card Directive, is usually due to a resistance of individual Member States. With deeper integration of the policy area over time and qualified majority voting, however, resistant minorities have been increasingly outvoted. The stronger politicization of some areas of immigration, such as family migration, has also led the European Commission to curb its legislative proposals, as it would be much harder to adopt a piece of legislation today (2019) that provides adequate protection standards.