bluuebunny/crossref_metadata_2025 huggingface dataset:
Solar atmosphere radiative transfer model comparison based on 3D MHD simulations
Authors: Haberreiter M. , Criscuoli S. , Rempel M. , Pereira T. M. D.
Published: July 2021

Context. The reconstruction of the solar spectral irradiance (SSI) on various time scales is essential for the understanding of the Earth’s climate response to the SSI variability.

Aims. The driver of the SSI variability is understood to be the intensity contrast of magnetic features present on the Sun with respect to the largely non-magnetic quiet Sun. However, different spectral synthesis codes lead to diverging projections of SSI variability. In this study we compare three different radiative transfer codes and carry out a detailed analysis of their performance.

Methods. We perform the spectral synthesis at the continuum wavelength of 665 nm with the Code for Solar Irradiance, and the Rybicki-Hummer, and Max Planck University of Chicago Radiative MHD codes for three 3D MHD simulations snapshots, a non-magnetic case, and MHD simulations with 100 G, and 200 G magnetic field strength.

Results. We determine the intensity distributions, the intensity differences and ratios for the spectral synthesis codes. We identify that the largest discrepancies originate in the intergranular lanes where the most field concentration occurs.

Conclusions. Overall, the applied radiative transfer codes give consistent intensity distributions. Also, the intensity variation as a function of magnetic field strength for the particular 100 G and 200 G snapshots agree within the 2–3% range.
Effect of freshwater discharge from Namgang Dam on ichthyoplankton assemblage structure in Jinju Bay, Korea
Authors: Myoung Se Hun , Kwak Seok Nam , Kim Jin-Koo , Williamson Jane E.
Published: July 2021

The movement of fish eggs and larvae in bay and estuarine systems is affected by freshwater discharge. In this study, the assemblage structures of ichthyoplankton eggs and larvae were assessed for the first time in Jinju Bay, South Korea, to identify the spawning and nursery functions of the bay. Fish eggs and larvae and several environmental parameters were sampled monthly from April 2015 to March 2016 inside and outside of the bay. Within the bay we collected eggs and larvae from 25 and 35 species, respectively, indicating greater diversity than outside the bay, where we collected eggs and larvae of 20 and 28 species, respectively. Fluctuations in water temperature and salinity were larger inside than outside of the bay, and chlorophyll-a concentration was higher within the bay, likely due to discharge from the Namgang Dam, which causes water to flow from the inside to the outside of the bay. This process influences fish larva abundance, such that more larvae are found outside than inside the bay. We also found that 28 fish species use Jinju Bay as a spawning ground. For some species, the timing of egg and larva appearance differed inside and outside of the bay, suggesting that the timing of spawning may differ between the two environments.
Friedel oscillations and charge density wave pinning in quasi-one
dimensional conductors: Thermal effects
Authors: Pouget J.-P. , Ravy S. , Rouziere S. , Brazovskii S.
Published: July 2021

An original interference effect observed in one-dimensional (1D) disordered conductors between X-ray
scattering due to the disorder and the charge density wave (CDW)- periodic lattice modulation (PLD) allows to
study the pinning of the modulation at local scale. We apply this effect to determine the phase of the CDW at the
pinning centres and to show that the response of the CDW to the impurity potential leads to the formation of Friedel
oscillations (FO). We report experimental determination and quantitative interpretation of the thermal evolution of
both features. The thermal dependence of the interference effect allows one to determine the pinning energy of the
2kF-CDW in the V-and W-doped blue bronzes. We show in particular that in these compounds the regular CDW is
pinned to the dopant dressed by its FO. In the organic charge transfer salts irradiation leads to an enhancement of
the 2kF and 4kF X-ray scattering that we show, by its thermal dependence, to be due to the formation of FO.
Unconventional density wave in the pseudogap phase of high Tc
cuprates
Authors: Maki K. , Dora B. , Virosztek A.
Published: July 2021

We propose here that the pseudogap phase of high Tc superconductors is probably
unconventional spin density wave (USDW). We present our analysis on the angular dependent
magnetoresistance (ADMR) in the pseudogap phase which should be accessible experimentally.
Also this result applies also to the AF phase of URu2Si2. We show that this model is consistent
with the optical dichroism seen by ARPES.
Photo-emission properties of quasi-one-dimensional conductors
Authors: Agic Z. , Zupanovic P. , Bjelis A.
Published: July 2021

We calculate the self-energy of the one-dimensional electron band with the three-dimensional long-range
Coulomb interaction within the random phase approximation, paying particular attention to the contribution coming
from the electron scatterings on the collective plasmon mode. It is shown that the spectral density has a form of wide
feature at the frequency scale of the plasmon frequency, without the presence of quasi-particle δ-peaks. The
relevance of this result with respect to experimental findings and to the theory of Luttinger liquids is discussed.
Polarons at the field-effect junctions
Authors: Kirova N. , Bussac M.-H.
Published: July 2021

We consider the interface of a molecular crystal with a polar dielectrics. Coulomb
interaction of free electrons in the crystal with surface polar phonons of the dielectrics can lead to
self-trapping of carriers. For typical parameters of field effect transistors the binding energy is found
to be high enough t o allow for formation of a strongly coupled polaron. The effect is further enhanced
at presence of the bias electric filed.
Theory of the ferroelectric Mott-Hubbard phase
in organic conductors
Authors: Brazovskii S.
Published: July 2021

Recently the ferroelectric FE anomaly (Nad, Monceau, et al.) followed by the charge
disproportionation CD (Brown, et al) have been discovered in ($TMTTF)_2X$ compounds. A
theory of the combined Mott-Hubbard state describes both effects by interference of the build-in
nonequivalence of bonds and the spontaneous one of sites. The state gives rise to three types of
solitons: $\pi -$ solitons (holons) are observed via the activation energy A in conductivity G; noninteger
$\alpha -$ solitons provide the frequency dispersion of the FE response; combined spin-charge solitons
determine $G(T)$ below subsequent phase transitions. The optical edge lies well below the conductivity
gap 2A; the critical FE mode coexists with a combined electron-phonon resonance and a phonon
antiresonance. The CD and the FE can exists hiddenly even in the Se subfamily giving rise to the
unexplained yet low frequency optical peak, the enhanced pseudogap and traces of phonons activation.
A model of coherent creep and switching in charge density wave
conduction in NbSe3 at low temperatures
Authors: Gill J. C.
Published: July 2021

A model is proposed of the temporally ordered collective creep with finite threshold field, and of the
“switching" transition to a hgNy conducting state at a higher threshold, observed in charge-density wave
conduction in niobium triselenide by Lemay et al. [phys. Rev. Lett. 83,2793 (1999)].
The model is based on their suggestion that the creep involves the thermally activated advance of wavelengths of CDW
past individual impurities. In
the model this is achieved by the formation near the impurity of a dislocation loop, which collapses after encircling
it. Switching is attributed to a transition, induced by stress associated with the motion, to a situation in which
collapse is avoided, enabling the CDW to advance indefinitely. The model accounts quantitatively for the observed
creep, and exhibits switching and hysteresis qualitatively similar to that observed.
Plastic depinning in artificial vortex channels:
Competition between bulk and boundary nucleation
Authors: Morais Smith C. , Drose T. , Besseling R. , Kes P.
Published: July 2021

We study the depinning transition of a driven chain-like system in the presence of frustration
and quenched disorder. The analysis is motivated by recent transport experiments on artificial
vortex-flow channels in superconducting thin films. We start with a London description of the
vortices and then map the problem onto a generalized Frenkel-Kontorova model and its
continuous equivalent, the sine-Gordon model. In the absence of disorder, frustration reduces
the depinning threshold in the commensurate phase, which nearly vanishes in the
incommensurate regime. Depinning of the driven frustrated chain occurs via unstable
configurations that are localized at the boundaries of the sample and evolve into topological
defects which move freely through the entire sample. In the presence of disorder, topological
defects can also be generated in the bulk. Further, disorder leads to pinning of topological
defects. We find that weak disorder effectively reduces the depinning threshold in the
commensurate phase, but increases the threshold in the incommensurate phase.
Thermal hysteresis in low frequency dielectric response of charge
density wave systems TaS3 and K0.3Mo03
Authors: Akrap A. , Staresinic D. , Biljakovic K. , Lunkenheimer P. , Loidl A.
Published: July 2021

Low frequency dielectric response of charge density wave systems K0.3MoO3
and o-TaS3 shows hysteresis
on temperature cycling. The closing of the hysteresis at low temperature coincides in both systems with the closing
of the hysteresis in DC conductivity and corresponds to the temperature of the glass transition observed in dielectric
response of these two systems. AC conducitivity is higher on heating, while DC conductivity is lower, i.e. two
loops have opposite directions. Higher AC conducitivity (or dielectric response) is a consequence of more
corrugated CDW phase on heating.
Transverse depinning threshold revealed by non linear Hall effect
of Wigner solid in a disorder field
Authors: Williams F. I.B. , Perruchot F. , Etienne B. , Mellor C. J. , Gaal R. , Sas B. , Hannini M. , Foxon T. , Harris J.
Published: July 2021

Both electrons and holes at a GaAs/GaAlAs heterojunction show a non linear Hall effect as a
function of current in the magnetically induced Wigner solid phase. Arguing that this arises
from a threshold Lorentz force transverse to the current lines, this threshold is found to be
proportional to the longitudinal depinning threshold and about 10% of its value. This is to be
compared with theoretical predictions by Giamarchi and LeDoussal and with numerical
simulation results (Moon, Scalettar and Zimanyi).
Electron paramagnetic resonance in the quasi-two dimensional
magnetic ludwigite Fe3O2BO3
Authors: Dumas J. , Tholence J. L. , Continentino M. , Fernandes J. C. , Guimaraes R. B. , Whangbo M. H.
Published: July 2021

We report an EPR study of the quasi-two dimensional oxide Fe3O2BO3
which shows a structural
transition at 283 K, an antiferromagnetic transition at 112K and weak ferromagnetism below 73 K. The single crystals
show three strongly anisotropic lines with different temperature dependences of their widths and resonance fields.
The results are discussed in relation with the different phase transitions and with the Wigner glass phase which
appears between ~112 K and ~200 K.
Optical properties of complex oxides:
Vanadate ladders
and related inorganic nanotubes
Authors: Musfeldt J. L. , Sushkov A. B. , Jegoudez J. , Revcolevschi A. , Millet P. , Galy J.
Published: July 2021

Optical spectroscopy is a sensitive probe of charge, spin, and lattice degrees of freedom. In
this talk, I will detail our magneto-optical work on alpha'-NaV2O5, a prototypical ladder
material, as well as the new Na2V3O7 nanotubes. Using changes in electronic structure with
temperature and applied magnetic field, we have mapped out the H-T phase diagram of
alpha'-NaV2O5. We find a temperature independent phase boundary at 27 T which persists
above Tc (34 K), a kink in Tc(H) near 27 T, and H$\wedge $2 behavior of Tc(H) in the high field
phase with an unusually small coupling constant. The energy scale of Tc and the newly
discovered phase boundary at Hc (27 T) are identical. Confinement effects are investigated in
the related nanotubes. Results include a larger gap than in analogous bulk materials as well
as a low-energy rattling mode, which corresponds to the motion of Na+ ions inside the
nanotube.
FISDW in quasi-one dimensional organic conductors
with the dimerized
gap due to anion ordering
Authors: Matsunaga N. , Ayari A. , Moncea P. , Yamashita K. , Ishikawa A. , Nomura K. , Watanabe M. , Yamada J. , Nakatsuji S.
Published: July 2021

Magnetoresistance and Hall resistance measurements have been carried out in the
FISDW phase of deuterated (TMTSF)2C1O4 for various cooling rates through the anion ordering
temperature. The Hall resistance in the intermediate cooled state, observed a very stable quantum
Hall state above 9.0 T for slowly cooled, shows a step-like change from the phase between 10 and 17
T to the phase between 20 and 25 T with hysteresis between 14 and 21 T. This result suggests that
there is a new phase transition around 15 T in deuterated (TMTSF)4ClO4. A possible ground state
of the FISDW phase of (TMTSF)2C1O4 for various cooling rates is discussed from the viewpoint
of the peculiar SDW nesting vector stabilized by the dimerized gap due to anion ordering.
Modelling nitriding of iron: From thermodynamics to residual stress
Authors: Somers M. A.J.
Published: July 2021

The present article presents a few selected aspects of the modelling of gaseous nitriding of
pure iron. After descriptions of the thermodynamics of the gas phase and the reactions at the gas/solid
interface, a model description of the thermodynamics of
$\gamma'-Fe_{\rm 4}N{\rm 1-x}$ is given, which
takes the long-range ordering of nitrogen atoms into account. Subsequently, the kinetics of nucleation
and growth of iron nitride layers is described in terms of the rates of the surface reactions and solid
state diffusion. Thereafter, the mechanisms of stress generation in
$\gamma'-Fe_{\rm 4}N{\rm 1-x}$ layers during
nitriding are summarized. Finally, the model for stress development in
$\gamma'-Fe_{\rm 4}N{\rm 1-x}$ layers is
compared with published experimental work.
Oxide reduction and diffusion in Fe-Cr alloy honeycombs
Authors: Nadler J. H. , Sanders T. H. , Cochran J. K. , Kim S. S.
Published: July 2021

The goal of this study is to develop practices for evaluating and predicting the microstructural evolution of directly reduced iron-chromium alloys. This fundamental knowledge is being applied to a process developed at the Georgia Institute of Technology to fabricate metal honeycomb extrusions. A paste composed of oxide powders, binders and lubricants is extruded through a die of the desired cross-section and subsequently reduced to metal with hydrogen. The effects of time, temperature and composition on the extent of reduction and diffusion in reducing Fe2O3-Cr2O3 powder mixtures is investigated. The thermodynamics and kinetics of Fe2O3-Cr2O3 reduction are evaluated in terms of the free energy of formation as well as reducing species. The kinetics of the microstructural changes are evaluated through diffusion measurements. A thermodynamic model for Fe2O3-Cr2O3 was developed and used to determine the maximum amount of Cr2O3 that would reduce when in contact with iron as a function of the $\frac{P_{H_{2}}}{P_{H_{2}O}}$ ratio . Diffusion studies consisted of Fe-Cr2O3 couples held at temperature in a reducing atmosphere. Cr diffusion in Fe showed a concentration dependence for the geometries investigated.
Extraction of boron Fe8B2 ribbons by annealing under hydrogen flow
Authors: Saage G. , Roth S. , Eckert J. , Schultz L.
Published: July 2021

Transition metal alloys often are difficult to be prepared as ribbons by conventional methods. If boron is added to these alloys, amorphous ribbons may be prepared by melt spinning. These amorphous ribbons have a better workability than their crystalline counterparts. However, the composition is different from the target composition. Upon annealing treatments in flowing hydrogen the boron may be extracted and the ribbon crystallizes. Thermodynamically the extraction of boron proceeds by the reaction of hydrogen with the borides formed during the crystallization of the ribbons. In order to investigate this extraction in more detail Fe8B2 amorphous ribbons were used. Thermogravimetric measurements were made at three different heating rates which permit to develop a thermokinetic description of the extraction process, which is controlled by chemical reactions and diffusion. The description allows to calculate the degree of boron extraction for various annealing procedures.
Phases transformation textures in steels
Authors: Cabus C. , Regle H. , Bacroix B.
Published: July 2021

Low-carbon steels used for deep-drawability applications have properties which depend greatly on their crystallographic texture. It is therefore important to control the texture evolution during the thermomechanical processing. Until recently, little attention has been paid on the understanding of the textures formation after hot-rolling, which are produced by phase transformation, although it is recognised that they have an effect on the development of the texture in the further process (cold rolling and annealing). Indeed, one of the main difficulties consists in the measurement of texture above ambient temperature, in the austenite range. In the present work, EBSD technique is employed on a low-C steel and a method is proposed to determine local austenite orientation thanks to martensitic one, even if there is no residual austenite in the steel. The orientation relationships between the austenite phase and each of its product phases, here martensite and polygonal ferrite, are analysed and compared. Common Kurdjumov Sachs variants are detected for both phases. Variations in the intensities of these variants are also detected and could be due to the different phase transformation mechanisms, diffusion or shear.
Modelling descaling during hot rolling of steel
Authors: Ramírez-Cuellar J. , Guerrero-Mata M. P. , Leduc L. A. , Colás R.
Published: July 2021

A computer model was developed to study the stresses that develop within the oxide formed on the surface of reheated steel slabs. The model considers that the crust grows during reheating following temperature dependent parabolic rates, and, as result of its thickness and growth rate, it will be stressed. Removal of this crust takes place by the impingement of water from high pressure jets installed in descaling units, which are located prior to deformation to avoid oxide imprint on the steel surface. Removal of the oxide layer depends on the velocity and amount of the water, as well as the force of the impact. A criterion based on these parameters can be established to determine the feasibility for oxide removal.
Optimal control strategies for the surface hardening of steel
Authors: Hömberg D. , Volkwein S. , Weiss W.
Published: July 2021

We discuss control strategies for the surface hardening of steel with laser or
electron beam. The goal is to acchieve a prescribed hardening depth avoiding
surface melting. Our mathematical model consists of a system of ODEs for the
phase volume fractions coupled with the heat equation. The system is solved
semi-implicitely using the finite element method. For the optimal control we
discuss two approaches: model reduction using POD (Proper Orthogonal
Decomposition) and a feedback control of temperature. The numerical results
prove that it is not sufficient to control the surface temperature in order to
obtain a uniform hardening depth. Instead the best strategy should be to
compute the optimal temperature in the hot spot of the beam by solving the
control problem and use this temperature as the set-point for the pyrometer
control of the real process.
Modelling of laser induced surface modification of ceramic substrates
Authors: Duitsch U. , Schreck S. , Rohde M.
Published: July 2021

A laser supported process has been developed to modify the electrical and thermal properties of ceramic substrates locally. This process is characterised by a strong thermal interaction between the laser beam and the ceramic surface which leads to localised melting. During the dynamic melting process an additional metallic material is introduced. After the solidification a metal-ceramic composite has been generated with different physical properties compared to the non-modified ceramic. The heat and mass transfer during this dynamic melting and solidification process has been studied experimentally and also numerically in order to identify the dominating process parameters. Simulation tools based on a finite element model have been developed to describe the heat transfer, fluid flow and the phase change during the melting and solidification of the ceramic. The results of the calculation have been validated against experimental results.
Modelling of laser cladding of medium carbon steel - a first approach
Authors: Ahlström J. , Karlsson B. , Niederhauser S.
Published: July 2021

A model on laser cladding of medium carbon steel, used in railway wheels and rails, is developed and implemented. When the laser beam is scanned over the surface during the cladding operation, phase transformations occur in the topmost layer of the substrate material due to rapid heating and cooling. The hardened regions may later be annealed, either during subsequent passes of the laser beam or by for example induction heating. The current model is a first step towards judging the resulting microstructure and hardness in the heat affected zone under the clad.
Computer simulation of induction surface hardening axially symmetric workpieces
Authors: Landek D. , Cajner F. , Filetin T.
Published: July 2021

To achieve a higher quality process planning and a more flexible execution of induction hardening computer simulation of electromagnetic and thermodynamic processes as well as microstructural transformation is recommended. This paper describes and suggests an own simulation model of the induction hardening process and explains a special simulation program that has been developed for the surface induction hardening of axially symmetric steel workpieces. The simulation program performance has been tested by experiments in some cases of high frequency induction hardening cylindrical specimens made of DIN 42CrMo4 steel grade. The measured values of surface hardness and hardening depths have been compared with the simulated values and a good correspondence between simulated and measured values has been obtained.
Numerical simulation of heat transfer in loaded heat treatment furnaces
Authors: Kang J. , Rong Y. K. , Wang W.
Published: July 2021

Heat transfer simulation within heat treatment furnaces is of great significance for the prediction and control of the ultimate microstructure, properties and dimensional stability of the workpieces and even the performance of furnaces. In this paper a set of models is proposed to solve heat transfer problems in a loaded furnace, including radiation, convection and conduction. Furthermore, a 3-dimensional algorithm based on finite difference method (FDM) is presented with a complete system for process simulation system.
In the radiation module, view factor is calculated by direct integral method for all element pairs exposed to each other based on the blocking judgment. Combustion in gas-fired furnace and PID control are also included in the furnace model. The heat transfer models are integrated with furnace model to simulate the heating process of workpieces. Temperature distribution in workpiece and its variation with time are predicted by the system. An experiment is carried out for the validation of the system.
Using the jominy end-quench test for validation of thermo-metallurgical model parameters
Authors: Hunkel M. , Lübben Th. , Hoffmann F. , Mayr P.
Published: July 2021

One of the most popular tests to determine the hardenability of steels is the Jominy-End-Quench-Test. Moreover this test is useful for simulation testing, too. In this paper the determination of heat transfer fluxes over the quenched surface as well as over the peripheral surface is described. The result is used for simulations of the Jominy-End-Quench-Test for two melts of SAE 52100 (100 Cr 6). One of these was taken from literature, one was used for experiments in IWT. Though transformation behaviors differ in an extreme way, the Jominy-End-Quench-Test can be simulated for both steels with good agreement between simulation and measurement.
Microstructure evolution in cold rolled strips during continuous annealing - modelling and simulation
Authors: Hein V. , Freydank H. , Michel U. , Zieger H. , Zouhar G. , Foerster P. , Rühl H.
Published: July 2021

The empirical optimization of technologies for continuous annealing of cold rolled strips is very time, material and cost intensive. The properties of cold rolled strips demanded by the customer are adjustable only in relatively closely limited temperature - time regimes. Therefore, it is a complex task to increase the performance of continuous annealing furnaces without disadvantages for the product quality. This problem can be solved by nume-rical modelling the microstructure evolution in the cold rolled strip during continuous annealing combined with experimental simulation of the annealing process. At the Institut für Werkstoffwissenschaft, Technische Universität Dresden, in co-operation with EKO Stahl GmbH, Eisenhüttenstadt, a computer program signed as TFB was deve-loped. It is suited for modelling and simulating the recrystallization kinetics in cold rolled strips during continuous annealing. Furthermore, this program can be used for optimizing the annealing technology. For example, for IF steel the pre-sent paper demonstrates to what extent the performance of a continuous annealing furnace can be increased. Further results concern the improvement of the microstructure of the high strength microalloyed steel ZStE 380 Z by optimizing the annealing technology by means of experimental simulation.
Stress affected transformation in low alloy steels – factors limiting prediction of plastic strains
Authors: Ahrens U. , Maier H. J. , A.EL.M. Maksoud
Published: July 2021

The present study identifies key material phenomena that limit the predictive capabilities of current approaches employed in modelling heat treatments of steels. Focus is on aspects relating to isothermal transformation in low alloy steels. Specifically, experimental data are presented relating to the effects of small plastic deformation on the kinetics of the phase transformation and on transformation plasticity. In addition, stress-strain response of supercooled austenite prior to transformation, i.e. in the temperature range between the A3-temperature and the martensite start temperature, has been determined experimentally. The data obtained demonstrate that the experimental results are only partially compatible with assumptions made in current models that are employed in modelling of heat treatments of steels.
Experimental and numerical simulation of thermomechanical phenomena during a TIG welding process
Authors: Depradeux L. , Jullien J.-F.
Published: July 2021

In this study, a parallel experimental and numerical simulation of phenomena that take place in the Heat Affected Zone during TIG welding on 316L stainless steel is presented. The aim of this study is to predict by numerical simulation residual stresses and distortions generated by the welding process. For the experiment, a very simple geometry with reduced dimensions is considered: the specimens are disks, made of 316L. The discs are heated in the central zone in order to reproduce thermo-mechanical cycles that take place in the HAZ during a TIG welding process. During and after thermal cycle, a large quantity of measurement is provided, and allows to compare the results of different numerical models used in the simulations. The comparative thermal and mechanical analysis allows to assess the general ability of the numerical models to describe the structural behavior. The importance of the heat input rate and material characteristics is also investigated.
Simulation of gas quenching
Authors: Frerichs F. , Lübben Th. , Fritsching U. , Lohner H. , Rocha A. , Löwisch G. , Hoffmann F. , Mayr P.
Published: July 2021

The prediction of mechanical behaviour of specimen during heat treatment by means of numerical simulation requires numerous modules e.g. for heat transfer and mechanical behaviour. The quality of predictions depend on the quality of the applied models within the modules. In this paper the strain hardening model used in the mechanical module will be investigated. For simulation of mechanical behaviour during gas quenching it is first of all necessary to calculate the interaction between gas and specimen. Using simulated flow field and temperature distribution within the gas, the heat transfer coefficient is calculated from computational fluid dynamics. The cooling and further the mechanical behaviour e.g. residual stresses and distortion of the specimen are simulated by a commercial Finite Element program. To investigate strain hardening it is helpful to choose in a first step a material that will not show phase transformations due to heat treatment. Therefore simulation of mechanical behaviour of austenitic cylinders (SAE30300) is investigated. The required thermo-physical properties such as thermal conductivity, density, and specific heat are taken from literature. With the exception of Poisson’s ratio the mechanical properties are measured and calculated by own investigations. For description of the temperature dependent stress strain curves the Ramberg-Osgood model is used. The simulated results are compared with experimental data in order to decide which model better describes the mechanical response, whether the kinematic or isotropic strain hardening.
Optimisation of high pressure gas quenching by application of CFD analysis
Authors: Schobesberger P. , Mann M. , Haigis M.
Published: July 2021

At Aichelin GmbH an experimental high pressure gas quenching facility was used for heat treatment of automotive parts. Since uniformity and core strength of the heat treated parts were insufficient, a CFD-analysis was carried out to investigate the influence of the flow field on the performance of the facility. The results showed that the design of the facility was quite unfavorable from a fluid dynamics point of view. Large variations of flow velocity occurred in the charge zone and high pressure loss was produced by reduced cross section at shut-off valves. An optimization of the existing facility did not seem promising. Consequently, a new facility concept was designed, incorporating the results of the previous simulation and again tested by means of numerical simulation. The charge was simulated by a grid of cylindrical parts and in addition the gas pressure was increased to 20 bars. The new design demonstrated a very homogeneous flow field in the vicinity of the charge and pressure drop was reduced by three quarters. However the attempted quenching performance was not yet achieved with the initial blower. The results from the simulation led to the design of a full scale industrial gas quenching facility with an improved fan. This facility was able to meet the requirements in terms of core strength and uniformity from the beginning.
Achieving manufacturing quality and reliability using thru-process simulation
Authors: Chen X. L. , Yang Z. , Nanjundan A. , Chen N. , Janosch J.-J.
Published: July 2021

Manufacturing of heavy industrial components such as the
front linkage, case frame and car body of construction and mining equipments
involves multiple processes including thermal cutting, bending/forming and
welding. Distortion, welding joint integrity and manufacturing variability
pose significant challenges on today's manufacturing. In this paper, the
authors presented VFT$^{\tiny TM}$- Virtual Fabrication Technology [1],
a thru-process simulation package, developed at the technical center of
Caterpillar Inc., Peoria, IL, USA and Battelle Memorial Institute, Columbus
Ohio, USA. VFT is a trademark of Battelle Memorial Institute. This work was
performed under the support of the US Department of Commerce, National
Institute of Standards, Advanced Technology Program. Steel rolling
simulation, thermal cutting simulation, bending and welding simulation
capabilities in the VFT software have significantly reduced the time and
cost of manufacturing process developments as well as to achieve competitive
advantages through quality improvement and differentiated products. Besides
the Caterpillar applications, VFT software has also found applications in
shipbuilding, nuclear piping, and automotive industry.
An integrated batch annealing furnace simulator
Authors: Sahay S. S.
Published: July 2021

An integrated batch annealing furnace simulator with the capability of predicting spatial and temporal evolution of temperature, microstructure and mechanical properties of the coils during the batch annealing operation has been developed. The prediction capability of this integrated simulator has been extensively validated with data collected from several industrial batch annealing operations. In this article, the problems in controlling a batch annealing operation via conventional temperature based control strategy has been highlighted. These problems can be effectively resolved by using the integrated simulator. Furthermore, the utility of this simulator has been illustrated by a case study on optimization of coil dimensions for maximization of furnace productivity.
Perioperative outcomes of frenectomy using laserversusconventional surgery: a systematic review
Authors: Lebret Clément , Garot Elsa , Amorim Pereira Mélodie , Fricain Jean-Christophe , Catros Sylvain , Fénelon Mathilde
Published: July 2021

Introduction:Frenectomy is an oral surgical procedure usually performed with a scalpel. Several authors recently reported the interest of laser, as a minimally invasive and efficient alternative tool to perform frenectomy. This study aimed to compare the perioperative management of patients requiring a frenectomy using scalpelversuslaser.Materials and methods:A systematic review of the literature has been carried out from Pubmed and Scopus databases following PRISMA guidelines. PICO method was used to select the relevant articles. Clinical studies comparing the perioperative outcomes of patients requiring frenectomies using scalpelversuslaser were included.Results:Ten articles involving 375 patients were included. Pre-operative parameter (anxiety before surgery) and per-operative data such as anesthesia, surgery duration, bleeding, suture and difficulty were assessed. The post-operative outcomes investigated were pain, analgesics use, functional discomfort, edema, healing and satisfaction of patients. Laser achieved satisfactory peri-operative outcomes such as shorter operative time, without suturing requirement, as well as less post-operative pain and functional discomfort.Discussion:The low number of eligible studies, the different type of lasers used and heterogeneity across the methodology of the selected studies were the limits of the study.Conclusion:Laser-assisted surgery became an attractive tool to perform oral soft tissue surgery.
Surveying the landscape of model livers assesses their role in drug development
Authors: Patrick Chris
Published: July 2021

An examination of case studies from the biopharmaceutical industry demonstrates how commercially available in vitro human liver models are used in drug development.
Latest impact of engineered human liver platforms on drug development
Authors: Monckton Chase P. , Brown Grace E. , Khetani Salman R.
Published: July 2021

Drug-induced liver injury (DILI) is a leading cause of drug attrition, which is partly due to differences between preclinical animals and humans in metabolic pathways. Therefore, in vitro human liver models are utilized in biopharmaceutical practice to mitigate DILI risk and assess related mechanisms of drug transport and metabolism. However, liver cells lose phenotypic functions within 1–3 days in two-dimensional monocultures on collagen-coated polystyrene/glass, which precludes their use to model the chronic effects of drugs and disease stimuli. To mitigate such a limitation, bioengineers have adapted tools from the semiconductor industry and additive manufacturing to precisely control the microenvironment of liver cells. Such tools have led to the fabrication of advanced two-dimensional and three-dimensional human liver platforms for different throughput needs and assay endpoints (e.g., micropatterned cocultures, spheroids, organoids, bioprinted tissues, and microfluidic devices); such platforms have significantly enhanced liver functions closer to physiologic levels and improved functional lifetime to >4 weeks, which has translated to higher sensitivity for predicting drug outcomes and enabling modeling of diseased phenotypes for novel drug discovery. Here, we focus on commercialized engineered liver platforms and case studies from the biopharmaceutical industry showcasing their impact on drug development. We also discuss emerging multi-organ microfluidic devices containing a liver compartment that allow modeling of inter-tissue crosstalk following drug exposure. Finally, we end with key requirements for engineered liver platforms to become routine fixtures in the biopharmaceutical industry toward reducing animal usage and providing patients with safe and efficacious drugs with unprecedented speed and reduced cost.
Polydimethylsiloxane diaphragm-based fiber ultrasonic sensor with high sensitivity and wide spectrum response range
Authors: Li Long , Wang Jun , Wang Wei , Wu Diyang , Song Ming , Wang Guanjun , Huang Mengxing
Published: July 2021

In order to effectively enhance the sensitivity and response range of optical fiber Fabry–Pérot (FP) ultrasonic sensors, this article proposes an implementation method of an optical fiber FP ultrasonic sensor with a controllable cavity length and variable diaphragm. On the basis of optimizing the viscosity coefficient of the polydimethylsiloxane (PDMS) material, a PDMS diaphragm with the thickness ranging from 20 to 60 µm is fabricated on the end face of a Φ200/128 µm hollow glass tube using a multiple transfer method. Then, a piece of Φ125 µm single-mode optical fiber is threaded into the hollow glass tube from the other end and encapsulated to form an optical fiber FP ultrasonic sensor based on a PDMS diaphragm. The intensity of the corresponding ultrasound signal and its spectral characteristics can be inverse-analyzed by detecting the FP interference spectra formed on the fiber end and the PDMS diaphragm surface under the action of dynamic ultrasound signals. The experimental results show that the highest ultrasonic detection frequency response of the proposed PDMS diaphragm optical fiber FP ultrasonic sensor can reach 430 kHz and the signal-to-noise ratio can reach up to 70 dB. The above-mentioned results indicate that the optical fiber FP ultrasonic sensor with a PDMS diaphragm proposed in this article has obvious advantages in terms of sensitivity and response range.
Ecological State Assessment Tool (ESAT): a cross-cultural natural resource management tool from Aotearoa, New Zealand
Authors: Belcher Sara M. , Mercier O. Ripeka , Foley Jeffery P. , Deslippe Julie
Published: July 2021

A cross-cultural approach to conservation and natural resource management will enable resource managers to access the full potential of dual knowledge epistemologies and facilitate genuine co-management. To achieve this epistemological convergence in Aotearoa, New Zealand, a framework and an ecological assessment tool are required that can employ indicators from both neoclassical ecological science and indigenous science, in particular mātauranga Māori. The Ecological State Assessment Tool (ESAT) was developed to assess quantitative scientific data using Māori ecological indicators. ESAT models population or social data weighted according to an applied Māori ecological perspective. ESAT may be applied to any conservation project to integrate Māori ecological knowledge in resource management. We illustrate the utility of ESAT in a case study of how different conservation management practices affect the ecological health of a short-tailed bat colony (Mystacina tuberculata), Pekapeka O Puketītī-Piopio. Applying ESAT shows that although pest control programs were achieving management targets, social engagement had a significant effect on ecological health outcomes for the bats. ESAT may assist territorial authorities and the Crown to meet their resource management obligations to Māori under the Treaty of Waitangi, value mātauranga and provide a way for Māori and ecologists to conceptualise and understand each other’s epistemology. Furthermore, ESAT can be adapted to include any cultural or ecological indicators, enabling its application internationally.
Native language, L2 experience, and pitch processing in music
Authors: Chen Ao , Çetinçelik Melis , Roncaglia-Denissen M. Paula , Sadakata Makiko
Published: July 2021

The current study investigated how the role of pitch in one’s native language and L2 experience influenced musical
melodic processing by testing Turkish and Mandarin Chinese advanced and beginning learners of English as an L2. Pitch has a lower
functional load and shows a simpler pattern in Turkish than in Chinese as the former only contrasts between presence and the
absence of pitch elevation, while the latter makes use of four different pitch contours lexically. Using the Musical Ear Test as
the tool, we found that the Chinese listeners outperformed the Turkish listeners, and the advanced L2 learners outperformed the
beginning learners. The Turkish listeners were further tested on their discrimination of bisyllabic Chinese lexical tones, and
again an L2 advantage was observed. No significant difference was found for working memory between the beginning and advanced L2
learners. These results suggest that richness of tonal inventory of the native language is essential for triggering a music
processing advantage, and on top of the tone language advantage, the L2 experience yields a further enhancement. Yet, unlike the
tone language advantage that seems to relate to pitch expertise, learning an L2 seems to improve sound discrimination in general,
and such improvement exhibits in non-native lexical tone discrimination.
Marking various aspects in Turkish Sign Language
Authors: Karabüklü Serpil , Wilbur Ronnie B.
Published: July 2021

Sign languages have been reported to have manual signs that function as perfective morphemes (Fischer & Gough 1999; Meir 1999; Rathmann 2005; Duffy 2007; Zucchi et al. 2010). Turkish Sign Language (TİD) has also been claimed to have such morphemes (Zeshan 2003; Kubuş & Rathmann 2009; Dikyuva 2011; Gökgöz 2011; Karabüklü 2016) as well as a nonmanual completive marker (‘bn’) (Dikyuva 2011). This study shows that the nonmanual ‘bn’ is in fact a perfective morpheme. We examine its compatibility with different event types and furthermore show that TİD has a manual sign bı̇t (‘finish’) that is indeed the completive marker but with possibly unusual restrictions on its use. Based on their distribution, the current study distinguishes bı̇t and ‘bn’ as different morphemes even though they can co-occur. TİD is argued to be typologically different from other sign languages since it has both a nonmanual marker (‘bn’) for a perfective morpheme and a manual sign (bı̇t) with different selectional properties than the manual signs reported for other sign languages.
Adventure Voluntourism: Help Manage Your Park
Authors: Bristow R. S.
Published: July 2021

Adventure tourists are engaged in a variety of activities around the world in parks and protected areas. For these tourists, one of the more popular interests is hiking. Hiking may involve a short walk in the local park or an extended long distance experience found during the pilgrimage on the Camino de Santiago or America’s long distance giant, the Appalachian Trail. Hikers can become the eyes and ears for park management, especially needed in the backcountry lands away from the busy trail.

Information

Adapted from ‘Chapter 12 - Altruistic Adventure Voluntourism: Help Manage the Park You Visit’. In: Jenkins, I. (Ed.) Adventure Tourism and Outdoor Activities Management: A 21
st
Century Toolkit. CABI, pp. 145-154.

© CAB International 2019
Development of the Joint-Venture Anvil Bay Chemucane Lodge in the Maputo Special Reserve, Mozambique
Authors: Spenceley Anna
Published: July 2021

This case explains the story of the establishment of Anvil Bay; a nine-chalet (18-bed) lodge situated in the Maputo Special Reserve in Mozambique. The government of Mozambique awarded a 50-year concession to the Ahi Zameni Chemucane Association, which in turn has a 25-year agreement with the Chemucane Tourism Company, a joint-venture company, to develop and operate the lodge. The development of the lodge has received technical and financial support from non-governmental organisations and a development bank.

Information

Snyman, S. and Spenceley, A. (2019) Private Sector Tourism in Conservation Areas in Africa, CABI, Chapter 4.1.1, Case study 19: Anvil Bay, Chemucane Lodge, Mozambique, pp96-99

© CAB International 2021
Nazy’s Battle to Change the Image of the Pankisi Valley through Tourism
Authors: Seabolt Katie , Couttet Alizée , Jeannon Marine
Published: July 2021

In creating Nazy’s Guest House, Nazy Dakishvili sought to change the image of the Pankisi Valley – the valley of the Kist’s – a region of Georgia whose reputation was damaged by fall-out from the Chechen conflict just across the border, decades ago. Her goal was to demonstrate to visitors from the outside world the unique culture and traditions of hospitality of her native land.

Information

Written on the basis of material provided by Nazy Dakishvili of Nazy’s Guest House.

© CAB International 2021
Exploring the Case Adventure Voluntourism: Help Manage Your Park
Authors: Bristow R. S.
Published: July 2021

Introduction

The Appalachian Trail (AT) is a 3,500 km long National Park. Because of its size and the history of development, volunteers have become essential partners in the trail management.
Exploring the Case Nazy’s Battle to Change the Image of the Pankisi Valley through Tourism
Authors: Ward-Perkins David
Published: July 2021

Introduction

The Pankisi Valley case brings to the surface a number of interesting and related issues relative to consumers’ perceptions of destinations and their host communities.

We live in a complex world and our interpretation of distant countries tends to be shaped by the simplified messages of the 24-hour news cycle. A localized earthquake or a single terrorist attack can colour our views of a whole country, immediately and negatively affecting tourist attitudes and travel plans.
A metal-free graphdiyne material for highly efficient oxidation of benzene to phenol
Authors: Yu Huidi , Hui Lan , Fang Yan , Xue Yurui , He Feng , Li Yuliang
Published: July 2021

Synthesizing active and durable catalysts for oxidizing benzene to phenol through benzene oxidation reaction (BOR) is of great significance for the next-generation phenol industry. The appearance of graphdiyne (GDY) brings us a very excited discovery that we can systematically study on theoretically and experimentally the exact location of active sites and reaction mechanisms of BOR using GDY as the model system. The results give us a clear understanding on the active sites responsible for BOR and sp-hybridized acetylenic bonds in GDY guarantees the activation of benzene molecule by forming new type of ‘–COO/–COOH’ active centers and efficient O transport of BOR kinetics, leading to efficient catalytic performances. The catalytic mechanism and process of GDY are clear and are the first class of metal-free catalysts capable of directly oxidizing benzene to phenol at ambient pressure and room temperature. The catalyst exhibits excellent catalytic activity with the average value of selectivity to be 82.29 ± 2.69% and the conversion to be 8.30 ± 0.66% at low temperature, superior to reported carbon materials.