Background
There is no internationally vetted set of anatomic terms to describe human surface anatomy.
Objective
To establish expert consensus on a standardized set of terms that describe clinically ...relevant human surface anatomy.
Methods
We conducted a Delphi consensus on surface anatomy terminology between July 2017 and July 2019. The initial survey included 385 anatomic terms, organized in seven levels of hierarchy. If agreement exceeded the 75% established threshold, the term was considered ‘accepted’ and included in the final list. Terms added by the participants were passed on to the next round of consensus. Terms with <75% agreement were included in subsequent surveys along with alternative terms proposed by participants until agreement was reached on all terms.
Results
The Delphi included 21 participants. We found consensus (≥75% agreement) on 361/385 (93.8%) terms and eliminated one term in the first round. Of 49 new terms suggested by participants, 45 were added via consensus. To adjust for a recently published International Classification of Diseases‐Surface Topography list of terms, a third survey including 111 discrepant terms was sent to participants. Finally, a total of 513 terms reached agreement via the Delphi method.
Conclusions
We have established a set of 513 clinically relevant terms for denoting human surface anatomy, towards the use of standardized terminology in dermatologic documentation.
Linked Commentary: R.J.G. Chalmers. J Eur Acad Dermatol Venereol 2020; 34: 2456–2457. https://doi.org/10.1111/jdv.16978.
Efficient application of a discrete element method (DEM) in modeling the behavior of granular materials requires contact models that reflect real behavior and realistic material parameters. The ...mechanical behavior of materials of biological origin is strongly influenced by the moisture content, which changes the surface and mechanical properties of seed endosperm and influences the bulk behavior. Laboratory tests and numerical DEM simulations were conducted to evaluate regions of validity for two basic contact models to describe the impact behavior of rapeseed at four moisture contents (5.5%, 7.5%, 14.7% and 34.0%). Seeds were allowed to free fall onto a flat surface from a height of 21
cm. Force–time waveforms were recorded using oscilloscope and rise and fall times were extracted for further analysis. DEM simulations were performed in which material parameters determined by a standard method fitted to two contact models were compared to experimental contact time measurements. The elastoplastic model was suitable for impact of dry seeds, whereas the viscoelastic model gave a better fit for wet seeds. An efficient criterion for model selection was the ratio of the fall time to the rise time (TR) for the contact force–time characteristic. For TR
<
1 the elastoplastic model is suitable, whereas for TR
>
1 the viscoplastic model should be applied.
Laboratory tests and numerical DEM simulations were conducted to describe impact behavior of rapeseeds at four levels of moisture content. Seeds were dropped by free fall on the force transducer. Force–time waveforms were recorded using oscilloscope. Elastoplastic model was found to describe fairly close the impact of dry seeds while in the case of wet seeds viscoelastic model provided better fit.
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The generation of a rarefaction wave at the initiation of discharge from a storage silo is a phenomenon of scientific and practical interest. The effect, sometimes termed the dynamic pressure switch, ...may create dangerous pulsations of the storage structure. Owing to the nonlinearity, discontinuity, and heterogeneity of granular systems, the mechanism of generation and propagation of stress waves is complex and not yet completely understood. The present study conducted discrete element simulations to model the formation and propagation of a rarefaction wave in a granular material contained in a silo. Modeling was performed for a flat-bottom cylindrical container with diameter of 0.1 or 0.12 m and height of 0.5 m. The effects of the orifice size and the shape of the initial discharging impulse on the shape and extent of the rarefaction wave were examined. Positions, velocities, and forces of particles were recorded every 10-5 s and used to infer the location of the front of the rarefaction wave and loads on construction members. Discharge through the entire bottom of the bin generates a plane rarefaction wave that may be followed by a compaction wave, depending on the discharge rate. Discharge through the orifice generates a spherical rarefaction wave that, after reflection from the silo wall, travels up the silo as a sequence of rarefaction-compaction cycles with constant wavelength equal to the silo diameter, During the travel of the wave along the bin height, the wave amplitude increases with the distance traveled. Simulations confirmed earlier findings of laboratory and numerical （finite element method） experiments and a theoretical approach, estimating the speed of the front of the rarefaction wave to range from 70 to 80 m/s and the speed of the tail to range from 20 to 60 m/s.
Nanosized LiMn sub(2)O sub(4) and LiMn sub(2)O sub(3.99)S sub(0.01) powders were prepared using a modified sol-gel method followed by calcination at 300 degreesC and further calcination at 650 ...degreesC in air. The high-temperature calcination was required to receive improved structural and electrical properties of the spinels. X-ray powder diffraction showed that for samples calcined at 650 degreesC, single phase materials of Fd-3m symmetry with nanoparticles size of ~50 nm were obtained. The LiMn sub(2)O sub(4) spinel showed the phase transition at about room temperature, but the effect was strongly diminished with the substitution of sulphur for oxygen in the spinel structure. Electrochemical results on 2032 coin-type cells reveal that slight substitution of sulphur in the LiMn sub(2)O sub(4) enhances the electrochemical performance and cell cydeability. The sulphided cathode material in which the capacity retention after 50 cycles is around 99% displays good rate capability, even at higher current densities.
The discrete element method is a promising approach to simulation of certain mechanical phenomena that cannot be modelled by means of the continuum mechanics approach. One of these phenomena is the ...anisotropy of loads exerted by granular deposits on the elements of a storage structure. In this project, DEM simulations were performed to examine the asymmetry of silo wall loads during eccentric filling and discharge of a model silo. The silo, with a diameter of approximately 26 particle diameters and a height of 2.5 silo diameters, was filled with 30,000 spherical particles. The configuration of the simulations reflected the conditions (but not the scale) of earlier laboratory tests on the filling and discharge of a 2.44-m diameter model flat-floor silo used for storage of wheat. The simulations were observed to adequately reproduce the qualitative behaviour of the loads during filling and discharge in the laboratory tests. The simulations underestimated the vertical wall loads compared with the experimental results. This underestimate is likely a result of the perfect spherical shape of the particles and the relatively weak damping of the translational and rotary vibrations in the test model.
DEM simulations were performed to examine silo wall loads during eccentric filling and discharge. The ratio of the number of wheat kernels in the silo to the number of particles in the simulation was approximately 16,000. The results of the simulations were found to adequately reproduce the quantitative behaviour of loads in a model silo storing wheat. Display omitted
► Simulations of non-axial silo filling and discharge were performed. ► Loads simulated in 0.1m cylinder and measured in 2.44m diameter bin were compared. ► Simulations fairly well reproduced some effects of flow pattern and loads asymmetry. ► DEM may explain phenomena of granular mechanics un-tackled by continuum mechanics.
Nanoporous carbon aerogels were synthesized by the carbonization of organic aerogels, derived from a sol-gel polymerization using various types of starch and followed by an ambient pressure drying. ...Optimal conditions for pyrolysis of organic aerogels were determined by TG/DTG/SDTA analysis. The structure and the morphology of the prepared carbon aerogels were investigated using XRD and N2-BET measurements respectively. Electrical properties of the obtained aerogels were examined by EC studies. Prepared carbon materials revealed high surface area and good electrical conductivity. Thus, one can say that carbon aerogels exhibit potential as new materials for energy applications (eg. supercapacitors, Li-ion batteries, etc.).
The nanometric copper doped Ce1−xCuxO2−δ materials were obtained using a modified reverse nanoemulsion method followed by a previously optimized calcination. XRD patterns confirmed the presence of ...only one, fluorite-like CeO2 phase, within the range of 0<x<0.12, in accordance with embedding Cu ions in the CeO2 phase. High increase of catalytic activity in oxidative incineration of volatile organic compounds (VOCs) with Cu-doping was observed, equally with a high increase in the ionic conductivity related to the increase of concentration of oxygen vacancies in the ceria lattice. The impedance spectroscopy allowed to specify that the high catalytic activity of Ce1−xCuxO2−δ is bounded also with change of the share in ionic and electronic conductivities. Though, the active catalyst should reveal mixed ionic and electronic conductivities (MIEC), the higher share of ionic component of electrical conductivity seems to be essential. Such a conclusion is in accordance with the Mars–van Krevellen model of catalytic oxidation of VOC molecules.
•Nanoemulsion method for synthesis of nanometric monophase ceria system is proposed.•High catalytic activity is related to high ionic conductivity.•Share of ionic conductivity in total conductivity is increased with temperature.•Mars–van Krevellen model of catalytic oxidation is confirmed.
Electrode materials in which tin nanograins are encapsulated in carbon matrix obtained from different origin (starch or modified polymer) were examined. Morphology of the C/Sn composites was observed ...using transmission electron microscopy (TEM). Electrochemical impedance spectroscopy (EIS) analysis in different states of charge (SOC) at initial cycle together with a long term galvanostatic charge-discharge cycling tests allowed determining the influence of carbon coating origin on the electrochemical behaviour of C/Sn nanocomposites. X-ray photoelectron spectroscopy (XPS) measurements of C/Sn materials before cycling and after first cycle were performed to observe changes in surface composition of the material which occur during electrochemical reaction. The results of surface characterization as well as electrochemical studies of C/Sn nanocomposites indicated that the origin of carbon precursor has a major impact on the composites’ morphology and electrochemical behaviour. Long term galvanostatic charge-discharge cycling tests proved that the carbon obtained from MPNVF precursor allows better encapsulation of tin nanograins in the buffer matrix. Furthermore, according to the XPS studies carbon coating based on MPNVF is more chemically stable versus electrolyte, which contributes directly to the improved protection of active material against physical damage. The charge capacity of MPNVF-based composite was 589mAhg−1 after 70 cycles, which constitutes 59% of theoretical metallic tin capacity.
In this paper we present structural, XPS, thermal (DSC and TG) and electrical (conductivity and thermoelectric power (TEP)) measurements of series of manganese spinel samples with manganese ...substituted to different degree (
x=0–0.5) with other 3d metals LiM
x
Mn
2−
x
O
4 (M=Cr, Fe, Co, Ni, Cu). Electrochemical studies of such characterized cathode materials were conducted in a Li/Li
+/Li
y
M
x
Mn
2−
x
O
4 type cell.
Substitution of manganese causes disappearance of the phase transition characteristic of a stoichiometric spinel. The small polaron mechanism of conductivity is preserved for substituted materials but with different activation energies. Studies of electrical properties reveal that Cr, Co and Ni doped ions do not participate in charge transport at low temperatures. In the charge curves of Li/Li
+/Li
y
M
x
Mn
2−
x
O
4 cells there are two visible plateaux, separated with distinct potential jump (0.5–0.7V), which position on Li content perfectly matches the Mn
3+ content in the doped cathode material. The lower plateau is related to the Mn
3+→Mn
4+ oxidation, while the next of higher voltage, to the M
m+
dopant oxidation. The schematic diagrams of relative Mn–M electronic levels alignment are proposed.
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