bluuebunny/crossref_metadata_2025 huggingface dataset:
Axilla versus Wrist as the Recipient Site in Vascularized Lymph Node Transfer for Breast Cancer-Related Lymphedema: A Systematic Review and Meta-Analysis
Authors: Chocron Yehuda , Azzi Alain J. , Bouhadana Gabriel , Kokosis George , Vorstenbosch Joshua
Published: December 2021

Background Vascularized lymph node transfers (VLNT) are being used with increasing frequency for the treatment of breast cancer-related lymphedema (BCRL). However, there is a lack of consensus in the surgical field as to which recipient site should be utilized. We, therefore, aim to assess the evidence comparing the wrist and axilla as recipient sites for VLNT in BCRL.

Methods We conducted a systematic literature review to compare the wrist and axilla as recipient sites for VLNT in BCRL. Demographic data, as well as circumference reduction rate (CRR), excess volume reduction (EVR), postoperative decrease in infections per year, postoperative discontinuation of compression garments, and overall pooled complication rate were extracted from included studies. These were compared through a meta-analysis.

Results A total of 37 studies met the inclusion criteria for a total of 689 patients. VLNTs to the wrist and axilla resulted in a decrease in CRR of 42.1 and 51.5%, and a decrease in EVR of 35.6 and 48.8%, respectively. However, our meta-analysis showed no significant differences between CRR or EVR and between wrist and axilla as recipient sites. Similarly, we found no differences in postoperative decrease in infections per year, postoperative discontinuation of compression garments, and overall pooled complication rate.

Conclusion These data suggest noninferiority between the wrist and axilla as recipient sites for VLNT in the context of BCRL. In the absence of randomized, prospective data, we hope these results can be used as an evidence-based reference and facilitate future studies.
Comparison of Scoring Systems for Mortality Prediction in Pediatric Multitrauma Patients
Authors: Çelegen Mehmet , Çelegen Kübra
Published: December 2021

The aim of this study was to compare scoring systems for mortality prediction and determine the threshold values of these scoring systems in pediatric multitrauma patients. A total of 57 multitrauma patients referred to the pediatric intensive care unit from January 2020 to August 2021 were included. The pediatric trauma score (PTS), injury severity score (ISS), base deficit (B), international normalized ratio (I), Glasgow coma scale (G) (BIG) score, and pediatric risk of mortality 3 (PRISM 3) score were analyzed for all patients. Of the study group, 35% were female and 65% were male with a mean age of 72 months (interquartile range: 140). All groups' mortality ratio was 12.2%. All risk scores based on mortality prediction were statistically significant. Cutoff value for PTS was 3.5 with 96% sensitivity and 62% specificity; for the ISS, it was 20.5 with 92% sensitivity and 43% specificity; threshold of the BIG score was 17.75 with 85.7% sensitivity and 34% specificity; and 12.5 for PRISM 3 score with 87.6% sensitivity and 28% specificity. PTS, ISS, BIG score, and PRISM 3 score were accurate risk predictors for mortality in pediatric multitrauma patients. ISS was superior to PTS, PRISM 3 score, and BIG score for discrimination between survivors and nonsurvivors.
Encephalitis, a Rare Manifestation of Human Herpesvirus 7 Infection
Authors: de Melo Parente Rita Guilherme Vilhena Pires , Pessoa Tânia Cristina , Moita Paula Cristina Afonso , dos Santos Sandra Cristina Campos , Pereira Ana Cristina Didelet , Castro Sofia Vidal
Published: December 2021

Human herpesvirus 7 (HHV-7) infection typically occurs in childhood and is frequently asymptomatic. Some clinical manifestations include fever and exanthem subitum. There have been rare reports of invasion of HHV-7 into the central nervous system. Here we report a case of encephalitis associated with HHV-7. A 16-year-old girl patient presented with headache, vomiting, disorientation, and psychomotor agitation. Glasgow Coma Scale on arrival was 9. Cerebrospinal fluid tested positive for HHV-7. Electroencephalogram showed intermittent slowing and rare sharp waves in the left frontal region. She recovered well after appropriate treatment for encephalitis.

This case added to the few existing reports of encephalitis due to HHV-7. Physicians should be aware of this rare neurological manifestation of HHV-7 for prompt management. Similar cases should be reported to further our knowledge about this virus and its role in neurological disease.
The dynamic state index with moisture and phase changes
Authors: Hittmeir Sabine , Klein Rupert , Müller Annette , Névir Peter
Published: December 2021

The dynamic state index (DSI) is a scalar field that combines variational information on the total energy and vorticity of a flow field with the second law of thermodynamics. Its magnitude is a combined local measure for non-stationarity, diabaticity, and dissipation in the flow, and it has been shown to provide good qualitative indications for the onset and presence of precipitation and the organization of storms. The index has been derived thus far for ideal fluid models only, however, so that one may expect more detailed insights from a revised definition of the quantity that includes more complex aerothermodynamics. The present paper suggests definitions of DSI-like indicators for flows of moist air with phase changes and precipitation. In this way, the DSI is generalized to signal deviations from a variety of different types of balanced states. A comparison of these indices evaluated with respect to one and the same flow field enables the user to test whether the flow internally balances any combination of the physical processes encoded in the generalized DSI-indices.
Momentum(k)-space carrier separation using SiGeSn alloys for photodetector applications
Authors: McCarthy Tyler T. , Ju Zheng , Schaefer Stephen , Yu Shui-Qing , Zhang Yong-Hang
Published: December 2021

A band-structure engineering approach is proposed to use semiconductor alloys such as SixGe1−x−ySny with a direct bandgap slightly above the indirect fundamental bandgap to demonstrate momentum(k)-space carrier separation of photogenerated carriers in photodetectors to reduce dark current. This approach combines the large absorption coefficient of direct-gap semiconductors with the long carrier lifetime of indirect gap semiconductors and reduces tunneling current due to the large effective masses of the indirect valleys. When the difference of the direct and indirect bandgaps (i.e., the energy difference between the direct and indirect valleys) varies from 0.4 to 3kBT, the direct-bandgap absorption covers a wide wavelength range from 2 to 22 μm for those alloys lattice matched to GeSn virtual substrates and to various commercially available substrates. The same approach can be adopted for other material systems.
Synthetic aperture interference light (SAIL) microscopy for high-throughput label-free imaging
Authors: Hu Chenfei , Kandel Mikhail E. , Lee Young Jae , Popescu Gabriel
Published: December 2021

Quantitative phase imaging (QPI) is a valuable label-free modality that has gained significant interest due to its wide potentials, from basic biology to clinical applications. Most existing QPI systems measure microscopic objects via interferometry or nonlinear iterative phase reconstructions from intensity measurements. However, all imaging systems compromise spatial resolution for the field of view and vice versa, i.e., suffer from a limited space bandwidth product. Current solutions to this problem involve computational phase retrieval algorithms, which are time-consuming and often suffer from convergence problems. In this article, we presented synthetic aperture interference light (SAIL) microscopy as a solution for high-resolution, wide field of view QPI. The proposed approach employs low-coherence interferometry to directly measure the optical phase delay under different illumination angles and produces large space-bandwidth product label-free imaging. We validate the performance of SAIL on standard samples and illustrate the biomedical applications on various specimens: pathology slides, entire insects, and dynamic live cells in large cultures. The reconstructed images have a synthetic numeric aperture of 0.45 and a field of view of 2.6 × 2.6 mm2. Due to its direct measurement of the phase information, SAIL microscopy does not require long computational time, eliminates data redundancy, and always converges.
Microstructure and high temperature tribological performance of Co-based laser cladded coatings reinforced with in situ TiN-VC
Authors: Ding Lin , Hu Shengsun , Quan Xiumin , Shen Junqi
Published: December 2021

Co-based laser cladded coatings reinforced with in situ TiN-VC were prepared. The microstructure and high temperature tribological performance of the cladded coatings were researched. Results revealed that TiN and VC were identified in the cladded coatings with in situ TiN-VC besides γ-Co and Cr23C6 phases. In situ TiN and VC promoted the formation of many short rod-shaped dendritic crystals and equiaxed crystals, refining the microstructure. Compared with the Co-based cladded coatings, the microhardness of the cladded coatings with in situ TiN-VC at 20 °C was improved by 30.0%, the mass loss was reduced by 51.3%, and the friction coefficient was obviously decreased. The mass loss and friction coefficient of the cladded coatings with in situ TiN-VC were both initially increased and subsequently decreased as the temperature was increased from 20 to 600 °C and were up to 12.2 mg and 0.256 at 400 °C, respectively. The abrasion mechanism was translated from the abrasive wear to the abrasive wear, adhesive wear, and oxidation wear.
Anomalous singularity of the solution of the vector Dyson equation in the critical case
Authors: Kolupaiev Oleksii
Published: December 2021

The vector Dyson equation (VDE) is an equation of the form −1/m = z + Sm, where S is a fixed square matrix, z lies in the complex upper half-plane, and m is a vector-function of z. We consider the solution of the VDE in the case when S has a block staircase structure with (n − 1) different critical zero blocks below the strictly positive anti-diagonal and all elements right above the anti-diagonal are strictly positive. We prove that the components of m behave as fractional powers of z in the neighborhood of zero and show that the self-consistent density of states ρ(E) behaves as |E|−n−1n+1 as E tends to zero, where n2 is the number of blocks. Both constant block and non-constant block cases are considered. In the non-constant case, uniform estimates for the components of m are obtained.
Numerical modeling of adjacent bubble interactions under the influence of induced vibrations in liquid pool using lattice Boltzmann method (LBM)
Authors: Mondal Kaushik , Bhattacharya Anandaroop
Published: December 2021

This paper reports our numerical investigation on the bubble dynamics of two adjacent bubbles formed on the heated surface as the liquid pool is subjected to induced vibrations caused by oscillating solid bodies in periodic motion. The modeling involves 2D simulations of the entire ebullition cycle comprising of bubble nucleation, growth, coalescence, and departure by employing a combination of multiple relaxation time based lattice Boltzmann method with the finite difference method based thermal model. The numerical results throw insight into the different processes pertaining to bubble growth in the two systems, viz., the quiescent system (QS) and the system with oscillating solid bodies (OSBS). These include the bubble growth rate, vapor bridge formation, subsequent coalescence, and movement of three-phase contact lines. It is observed that the induced vibrations in the liquid pool leads to earlier nucleation and growth of the bubbles, and higher bubble departure frequency (f∗) due to additional forces acting on the bubble, which at one instance helps the two adjacent bubbles to coalesce and at the following instance pulls the coalesced bubble off the solid surface. A force balance analysis is presented to explain the evolution of the adjacent bubbles and their interactions. A sensitivity study is conducted to investigate the effects of unequal sizes of nucleation sites, unequal surface superheat (Ja), and distance between the nucleation sites. In all these cases, multiple bubbles are seen to form on the heated elements, which subsequently coalesce with each other and depart in a single ebullition cycle in OSBS, whereas only two initially formed bubbles are seen to merge and depart in a single ebullition cycle in QS. Subsequently, a sensitivity study is conducted to investigate the effects of surface wettability, and it is found that for a given surface superheat (Ja) and configuration of nucleation sites, f* reduces after a threshold value of wetting angle (θ∗) in QS while it reaches a maximum in OSBS before coming down. It is further observed that if the hydrophobicity of the surface is increased from θ* = 1.0 to 1.1 in OSBS, f∗ remains high until a threshold Ja, beyond which it reduces drastically due to a higher rate of bubble generation compared to detachment.
High yields in direct-drive inertial confinement fusion using thin-ice DT liner targets
Authors: Williams C. A. , Betti R. , Gopalaswamy V. , Lees A.
Published: December 2021

We report simulation results that suggest record neutron yields above 3×1014 can be achieved in laser-driven fusion on OMEGA by imploding large-outer-diameter targets (∼1010 μm) containing ice layers as thin as 34 μm. Historically, the performance of thin and fast capsules is thought to be highly degraded by hydrodynamic instabilities. We present pulse designs that push implosion velocities above 650 km/s while maintaining enough ablative stabilization and low enough in-flight aspect ratios to survive the acceleration phase. We show that these targets also possess improved stability during deceleration stemming from augmented core temperatures and low fuel convergence.
Link cascades in complex networks: A mean-field approach
Authors: Wong King Chun , Li Sai-Ping
Published: December 2021

Cascade models on networks have been used extensively to study cascade failure in complex systems. However, most current models consider failure caused by node damage and neglect the possibility of link damage, which is relevant to transportation, social dynamics, biology, and medicine. In an attempt to generalize conventional cascade models to link damage, we propose a link cascade model based on the standard independent cascade model, which is then solved via both numerical simulation and analytic approximation. We find that the probability that a node loses all its links due to link damage exhibits a minimum as a function of node degree, indicating that there exists an optimal degree for a node to be most resistant to link damage. We apply our model to investigate the sign distribution in a real-world signed social network and find that such an optimal degree does exist in a real-world dataset.
Ultrasonic investigation of the evaporation dynamics of subnanoliter droplets
Authors: Raven Luong Quy , Hefele Andreas , Reiner Alexander , Hörner Andreas , Wixforth Achim
Published: December 2021

With the development of ink jet printers or spotters for biological applications, the control size and homogeneity of small fluids as well as their successful deposition on various substrates has gained significant importance. We study the impingement process of such small droplets onto a solid substrate and investigate their evaporation and drying process by means of surface acoustic wave (SAW) transmission experiments. We observe a strong fluid-SAW interaction resulting in an attenuation which toward the end of the evaporation and drying process exhibits characteristic oscillations being related to temperature, SAW amplitude, and fluid properties such as viscosity and wetting angle. It is found that oscillations can only be seen in pinned, very flat droplets, while the pinning can be roughly controlled via the SAW amplitude. The frequency of those characteristic oscillations is superlinear with respect to temperature, rather proportional to the evaporation rate and can change drastically depending on the liquid used. In our experiments, isopropanol, ethanol, and water with various glycerol concentrations were loaded onto the SAW delay line. Based on the experimental results, simulations using the finite element method were performed. We find that a standing wave pattern within the droplet is responsible for the transmission oscillations. These findings might lead to new methods, e.g., sensory systems, being able to examine droplets according to their physical or chemical properties.
The nature of column boundaries in micro-structured silicon oxide nanolayers
Authors: Patel K. , Cottom J. , Mehonic A. , Ng W. H. , Kenyon A. J. , Bosman M. , Shluger A. L.
Published: December 2021

Columnar microstructures are critical for obtaining good resistance switching properties in SiOx resistive random access memory (ReRAM) devices. In this work, the formation and structure of columnar boundaries are studied in sputtered SiOx layers. Using TEM measurements, we analyze SiOx layers in Me–SiOx–Mo heterostructures, where Me = Ti or Au/Ti. We show that the SiOx layers are templated by the Mo surface roughness, leading to the formation of columnar boundaries protruding from troughs at the SiOx/Mo interface. Electron energy-loss spectroscopy measurements show that these boundaries are best characterized as voids, which in turn facilitate Ti, Mo, and Au incorporation from the electrodes into SiOx. Density functional theory calculations of a simple model of the SiO2 grain boundary and column boundary show that O interstitials preferentially reside at the boundaries rather than in the SiO2 bulk. The results elucidate the nature of the SiOx microstructure and the complex interactions between the metal electrodes and the switching oxide, each of which is critically important for further materials engineering and the optimization of ReRAM devices.
High temperature characteristics of nitric oxide annealed p-channel 4H-SiC metal oxide semiconductor field effect transistors
Authors: Das Suman , Isaacs-Smith Tamara , Ahyi Ayayi , Kuroda Marcelo A. , Dhar Sarit
Published: December 2021

In this work, p-channel 4H-SiC MOSFETs were fabricated and analyzed at high temperature. It is demonstrated that nitridation of the gate oxide enables enhancement mode operation in these devices. Nitrogen incorporation at the 4H-SiC/SiO2 interface by nitric oxide annealing reduces the interface trap density energetically located in the lower half of the 4H-SiC bandgap, resulting in viable high temperature p-channel devices. In the 27–300 °C temperature range, the threshold voltage decreases with increasing temperature, consistent with the reduction of occupied interface traps at higher temperatures. The hole channel mobility is weakly temperature dependent under strong inversion conditions. Hall measurements support that above the threshold voltage, the mobility is limited by surface roughness scattering. In weaker inversion, the channel conductivity is limited by interface hole trapping and Coulomb scattering. In addition, high temperature bias stress measurements confirm a temperature activated hole trapping under negative gate bias, which requires further investigations.
Neighborhood size effects on the evolution of cooperation under myopic dynamics
Authors: Shi Juan , Liu Jinzhuo , Perc Matjaž , Deng Zhenghong , Wang Zhen
Published: December 2021

We study the evolution of cooperation in 2×2 social dilemma games in which players are located on a two-dimensional square lattice. During the evolution, each player modifies her strategy by means of myopic update dynamic to maximize her payoff while composing neighborhoods of different sizes, which are characterized by the corresponding radius, r. An investigation of the sublattice-ordered spatial structure for different values of r reveals that some patterns formed by cooperators and defectors can help the former to survive, even under untoward conditions. In contrast to individuals who resist the invasion of defectors by forming clusters due to network reciprocity, innovators spontaneously organize a socially divisive structure that provides strong support for the evolution of cooperation and advances better social systems.
Light extraction efficiency enhancement of CH3NH3PbBr3 light-emitting diodes using nanopatterned PEDOT:PSS layers
Authors: Weng Shukun , Sun Min , Zhang Liping , Jiang Lubing , Shi Chao , Du Weijie , Zhang Yiwen
Published: December 2021

Nanopatterned poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) layers fabricated by soft-nanoimprint were applied to CH3NH3PbBr3 (MAPbBr3) light-emitting diodes to enhance light extraction. The electric field distribution of MAPbBr3 devices with different periods of the nanopatterned PEDOT:PSS was calculated using the finite-difference time-domain method, demonstrating that the 400-nm period was more effective in improving light outcoupling. By integrating the nanopatterned PEDOT:PSS layer, the external quantum efficiency of the device increased from 6.5% to 10.3%. It can be attributed to the fact that the nanopatterned structure reduced the refractive index discontinuity at the interface between MAPbBr3 and PEDOT:PSS, thereby reducing light trapping in the waveguide mode.
A combined first principles study of the structural, magnetic, and phonon properties of monolayer CrI3
Authors: Staros Daniel , Hu Guoxiang , Tiihonen Juha , Nanguneri Ravindra , Krogel Jaron , Bennett M. Chandler , Heinonen Olle , Ganesh Panchapakesan , Rubenstein Brenda
Published: December 2021

The first magnetic 2D material discovered, monolayer (ML) CrI3, is particularly fascinating due to its ground state ferromagnetism. However, because ML materials are difficult to probe experimentally, much remains unresolved about ML CrI3’s structural, electronic, and magnetic properties. Here, we leverage Density Functional Theory (DFT) and high-accuracy Diffusion Monte Carlo (DMC) simulations to predict lattice parameters, magnetic moments, and spin–phonon and spin–lattice coupling of ML CrI3. We exploit a recently developed surrogate Hessian DMC line search technique to determine CrI3’s ML geometry with DMC accuracy, yielding lattice parameters in good agreement with recently published STM measurements—an accomplishment given the ∼10% variability in previous DFT-derived estimates depending upon the functional. Strikingly, we find that previous DFT predictions of ML CrI3’s magnetic spin moments are correct on average across a unit cell but miss critical local spatial fluctuations in the spin density revealed by more accurate DMC. DMC predicts that magnetic moments in ML CrI3 are 3.62 μB per chromium and −0.145 μB per iodine, both larger than previous DFT predictions. The large disparate moments together with the large spin–orbit coupling of CrI3’s I-p orbital suggest a ligand superexchange-dominated magnetic anisotropy in ML CrI3, corroborating recent observations of magnons in its 2D limit. We also find that ML CrI3 exhibits a substantial spin–phonon coupling of ∼3.32 cm−1. Our work, thus, establishes many of ML CrI3’s key properties, while also continuing to demonstrate the pivotal role that DMC can assume in the study of magnetic and other 2D materials.
Projection of future wildfire emissions in western USA under climate change: contributions from changes in wildfire, fuel loading and fuel moisture
Authors: Liu Yongqiang , Liu Yang , Fu Joshua , Yang Cheng-En , Dong Xingyi , Tian Hanqin , Tao Bo , Yang Jia , Wang Yuhang , Zou Yufei , Ke Ziming
Published: December 2021

Numerous devastating air pollution events from wildfire smoke occurred in this century in the western USA, leading to severe environmental consequences. This study projects future fire emissions in this region under climate change with a focus on comparing the relative contributions from future changes in burned area, fuel loading and fuel moisture. The three properties were projected using an empirical fire model, a dynamical global vegetation model and meteorological conditions respectively. The regional climate change scenarios for the western USA were obtained by dynamical downscaling of global climate projections. The results show overall increasing wildfires and fuel loading and decreasing fuel moisture. As a result, fire emissions are projected to increase by ~50% from 2001–2010 to 2050–2059. The changes in wildfires and fuel loading contribute nearly 75% and 25% of the total fire emission increase, respectively, but the contribution from fuel moisture change is minimal. The findings suggest that the air pollution events caused by wildfire smoke could become much more serious in the western USA by the middle of this century, and that it would be essential to take the future changes in fuel conditions into account to improve the accuracy of fire emission projections.
Unraveling the genotype by environment interaction in a thermosensitive fish with a polygenic sex determination system
Authors: Geffroy Benjamin , Besson Mathieu , Sánchez-Baizán Núria , Clota Frederic , Goikoetxea Alexander , Sadoul Bastien , Ruelle François , Blanc Marie-Odile , Parrinello Hugues , Hermet Sophie , Blondeau-Bidet Eva , Pratlong Marine , Piferrer Francesc , Vandeputte Marc , Allal François
Published: December 2021

Significance

Traditionally, fish sex determination was considered to be governed by genetic or environmental factors. However, many teleost species defy this dichotomy. We combined genomic and transcriptomic approaches to characterize the temperature-dependent polygenic sex determination of European sea bass. We observed that the estimated genetic sex tendency (eGST) provides an accurate estimation of the phenotypic sex. Our data support the hypothesis that sexually dimorphic growth is the consequence rather than the cause of sex determination. We also showed that temperature-induced masculinization involves the up-regulation of
sox3
and
sox9a
for individuals in the middle of the eGST distribution. We depict a sex determination system influenced by both continuous genetic and environmental variation that results in variable proportions of males and females.
A systematic review of experimental research in audiovisual translation 1992–2020
Authors: Wu Zhiwei , Chen Zhuojia
Published: December 2021

This study systematically reviewed 61 experimental studies on audiovisual translation (AVT), published in academic journals between 1992 and 2020. The review examined five aspects of these studies: publication trends, research scopes, research designs, statistical procedures, and reporting practices. Major findings include: (a) there has been a slight concentration of publication outlets for experimental AVT research; (b) the focal studies could be categorized into three themes (product, process, and pedagogy), with the product theme being the most popular and subtitling the dominant AVT modality; (c) the inclusion of a comparison group was the most common design feature, and questionnaires and tests were the most popular research instruments; (d) inferential statistical analysis was favored over descriptive statistical analysis; (e) data normality information and effect sizes were not regularly reported. Based on the systematic review, suggestions are made for the future development of experimental AVT research.
A cryo-ET survey of microtubules and intracellular compartments in mammalian axons
Authors: Foster Helen E. , Ventura Santos Camilla , Carter Andrew P.
Published: December 2021

The neuronal axon is packed with cytoskeletal filaments, membranes, and organelles, many of which move between the cell body and axon tip. Here, we used cryo-electron tomography to survey the internal components of mammalian sensory axons. We determined the polarity of the axonal microtubules (MTs) by combining subtomogram classification and visual inspection, finding MT plus and minus ends are structurally similar. Subtomogram averaging of globular densities in the MT lumen suggests they have a defined structure, which is surprising given they likely contain the disordered protein MAP6. We found the endoplasmic reticulum in axons is tethered to MTs through multiple short linkers. We surveyed membrane-bound cargos and describe unexpected internal features such as granules and broken membranes. In addition, we detected proteinaceous compartments, including numerous virus-like capsid particles. Our observations outline novel features of axonal cargos and MTs, providing a platform for identification of their constituents.
The intrinsic electrochemical behavior of layered Cu2WSe4 nanoparticles
Authors: Li Minyuan M , Ivanov Sergei A
Published: December 2021

Nanoplates of Cu2WSe4 (∼50 nm) were synthesized via a hot-injection method by one-pot selenation of WCl6 and Cu(acac)2. This synthetic route provided another perspective towards the intrinsic electrochemical properties of Cu2MSe4 (M = Mo or W), where their nanoparticles were previously synthesized via a metathesis route. Cations-dependent cathodic events and surface activation anodic events were identified by cyclic voltammetry in acetonitrile.
Synthesis of pseudo-CT images from pelvic MRI images based on an MD-CycleGAN model for radiotherapy
Authors: Sun Hongfei , Xi Qianyi , Fan Rongbo , Sun Jiawei , Xie Kai , Ni Xinye , Yang Jianhua
Published: December 2021

Objective. A multi-discriminator-based cycle generative adversarial network (MD-CycleGAN) model is proposed to synthesize higher-quality pseudo-CT from MRI images. Approach. MRI and CT images obtained at the simulation stage with cervical cancer were selected to train the model. The generator adopted DenseNet as the main architecture. The local and global discriminators based on a convolutional neural network jointly discriminated the authenticity of the input image data. In the testing phase, the model was verified by a fourfold cross-validation method. In the prediction stage, the data were selected to evaluate the accuracy of the pseudo-CT in anatomy and dosimetry, and they were compared with the pseudo-CT synthesized by GAN with the generator based on the architectures of ResNet, sUNet, and FCN. Main results. There are significant differences (P < 0.05) in the fourfold cross-validation results on the peak signal-to-noise ratio and structural similarity index metrics between the pseudo-CT obtained based on MD-CycleGAN and the ground truth CT (CTgt). The pseudo-CT synthesized by MD-CycleGAN had closer anatomical information to the CTgt with a root mean square error of 47.83 ± 2.92 HU, a normalized mutual information value of 0.9014 ± 0.0212, and a mean absolute error value of 46.79 ± 2.76 HU. The differences in dose distribution between the pseudo-CT obtained by MD-CycleGAN and the CTgt were minimal. The mean absolute dose errors of Dosemax, Dosemin, and Dosemean based on the planning target volume were used to evaluate the dose uncertainty of the four pseudo-CT. The u-values of the Wilcoxon test were 55.407, 41.82, and 56.208, and the differences were statistically significant. The 2%/2 mm-based gamma pass rate (%) of the proposed method was 95.45 ± 1.91, and the comparison methods (ResNet_GAN, sUnet_GAN, and FCN_GAN) were 93.33 ± 1.20, 89.64 ± 1.63, and 87.31 ± 1.94, respectively. Significance. The pseudo-CT images obtained based on MD-CycleGAN have higher imaging quality and are closer to the CTgt in terms of anatomy and dosimetry than other GAN models.
Strain-spectroscopy of strongly interacting defects in superconducting qubits
Authors: de los Santos-Sánchez Octavio , Román-Ancheyta Ricardo
Published: December 2021

The proper functioning of some micro-fabricated novel quantum devices, such as superconducting resonators and qubits, is severely affected by the presence of parasitic structural material defects known as tunneling two-level-systems (TLS). Recent experiments have reported unambiguous evidence of the strong interaction between individual (coherent) TLS using strain-assisted spectroscopy. This work provides an alternative and simple theoretical insight that illustrates how to obtain the spectral response of such strongly interacting defects residing inside the amorphous tunnel barrier of a qubit’s Josephson junction. Moreover, the corresponding spectral signatures obtained here may serve to quickly and efficiently elucidate the actual state of these interacting TLS in experiments based on strain or electric-field spectroscopy.
Bubble dynamics and mechanistic boiling heat transfer prediction on a scored copper surface
Authors: Cao Zhen , Wu Zan , Sundén Bengt
Published: December 2021

In this study, pool boiling heat transfer of de-ionized water was experimentally studied on a scored copper surface at a heat-flux range of 0 - 60 W/cm2. Bubble dynamics in an isolated bubble region were carefully investigated, including bubble departure diameters, bubble departure frequencies, and active nucleation site densities. The bubble dynamics were compared with available models, indicating the suitable models regarding the present experimental results. Then, based on the bubble dynamics, a mechanistic heat transfer model, developed in our previous studies, was employed to predict the present boiling curve. In the mechanistic model, heat fluxes from natural convection, transient heat conduction, and microlayer evaporation were incorporated.
Global sensitivity analysis of a pure steam dropwise condensation heat transfer model
Authors: Sablowski Jakob , Unz Simon , Beckmann Michael
Published: December 2021

Established heat transfer models for dropwise condensation (DWC) consider wetting behavior, surface structure and nucleation dynamics to calculate the heat flux. However, model results often deviate from experiments, in part due to uncertainties of the model input parameters. In this study, we apply quantitative sensitivity analysis to a pure steam DWC heat transfer model in order to attribute the variation of the model result to its input parameters. Four scenarios with different variations of the model parameters are discussed and sensitivity coefficients for each parameter are calculated. Our results show a high sensitivity of the model result towards the coating thickness, the contact angle and the nucleation site density, underlining the need to accurately determine these parameters in DWC experiments.
Experimental investigation of the thermal development of two nanofluids in laminar flow
Authors: Briclot A , Henry J F , Caron D , Popa C , Fohanno S
Published: December 2021

In this study, we conducted an experimental investigation of the thermal development of two nanofluids (γ-Al2O3 and TiO2 in deionized water) in a laminar pipe flow. To do so, the local Nusselt number is determined for Reynolds numbers from 650 to 1800. Experiments were carried out with water and two concentrations of water-based nanofluids with aluminum oxide and titanium oxide nanoparticles. The results show that the local Nusselt number remains unchanged with increasing mass concentration and that the process of thermal development is similar to that of water. Similarly, the friction factor is not affected by the addition of the nanoparticles, suggesting that these nanofluids behave like a homogeneous mixtures.
New H
2
O weighted sum of gray gases model for natural convection flows within large cavities
Authors: Liu Xiongguo , Kelm Stephan , Yin Chungen , Allelein Hans-Josef
Published: December 2021

Radiation heat transfer plays a significant role in buoyancy driven flows for large scale facilities. In the analysis of nuclear containment safety during severe accidents, it has been found that the thermal radiation particularly affects the temperature distribution and containment pressurization due to the humidity environment. In order to model thermal radiation, one of the main challenges is the description of nongray gas property for the steam-air mixtures. The weighted sum of gray gases model (WSGG) is a reasonable method in engineering applications because of its computational efficiency. There are many WSGG models available for combustion applications, but none of them is dedicated for low temperature applications. Furthermore, most of the existing WSGG models only provide the fixed partial pressure ratios (e.g., p

H

2

O
= 2p

CO

2 for methane). To overcome this limitation, a tailored WSGG model is derived by the Line-by-Line model for a gas mixture composed of arbitrary concentrations of H
2
O. This tailored WSGG model is valid for the pressure path length ranging from 0.0001 to 10 atm · m, and for the temperature from 300 to 1200 K. The WSGG correlations are verified against the Line-by-Line benchmark solutions with isothermal/non-isothermal temperatures and homogeneous/non-homogeneous concentrations. The results demonstrate the ability and efficiency of the new tailored WSGG formulation.
Using statistical inverse methods for detecting defects in electronic components
Authors: Bissuel Valentin , Dupuis Quentin , Laraqi Najib , Bauzin Jean-Gabriel
Published: December 2021

The thermal modeling of electronic components is mandatory to optimize the cooling design versus reliability. Indeed most of failures are due to thermal phenomena [1]. Some of them are neglected or omitted by lack of data: ageing, manufacturing issues like voids in glue or solder joints, or material properties variability. Transient measurements of the junction-to-board temperature supply real thermal behavior of the component and PCB assembly to complete these missing data[2]. To complement and supplement the numerical model, inverse methods identification based on a statistical deconvolution approach, such as Bayesian one, is applied on these measurements to extract a Foster RC thermal network. The identification algorithm performances have been demonstrated on numerical as well as experimental dataset. Furthermore defects or voids can be detected using the extracted Foster RC networks.
Ejector refrigeration: perspectives and comparative analysis
Authors: Besagni Giorgio , Croci Lorenzo , Bellasio Paolo , Maria Colombo Luigi Pietro
Published: December 2021

Within the broader discussion regarding the decarbonisation of the household sector, ejector refrigeration is attracting a growing attention. This communication contributes to the present day discussion concerning the performances and the perspectives in ejector refrigeration systems. Based on a very large dataset, gathered from the previous literature (encompassing a wide range of system design, operating conditions and refrigerants), this paper proposes a comprehensive comparative analysis. First, the current trends in ejector refrigeration systems, refrigerants and performances are presented. Second, the relationships between ejector performances, refrigerants and boundary conditions (in terms of non-dimensional temperatures, to ensure generality of the proposed analysis) are presented. In conclusion, this paper is intended to provide guidelines for perspective researchers and practitioners interested in selecting suitable ejector-based systems.
Thermal performance measurement of additive manufactured high-temperature compact heat exchangers
Authors: Fuchs M. , Heinrich D. , Luo X. , Kabelac S.
Published: December 2021

Due to increased distribution of high-temperature processes in energy and process plants, more efficient and compact high-temperature heat exchangers are being developed. The additive manufacturing allows the construction of compact sizes and application-specific requirements. To evaluate the thermal performance of these heat exchangers, experimental investigations are evident. This study presents a test rig for testing compact high-temperature heat exchangers as well as a first set of thermal performance data of an additively manufactured plate-fin heat exchanger. The test rig can provide a maximum fluid temperature of 900°C and a maximum mass flow rate of 0.8 kg/min. A steam unit can add steam to the fluid stream to evaluate the influence of gas radiation on the thermal performance. The capabilities of this test rig are being tested with the plate-fin heat exchanger, varying the mass flow rate between 0.2 - 0.52 kg/min at a hot and cold inlet temperature of 750°C and 250°C. The overall effectiveness of the heat exchanger is approx. 0.9.
Nanoencapsulated PCM slurries for the development of thermoregulating gypsums
Authors: López-Pedrajas D , Jiménez-Vázquez M , Borreguero A M , Ramos F J , Garrido I , Rodríguez J F , Carmona M
Published: December 2021

Gypsums with improved thermal properties have been obtained using a thermoregulatory nanocapsulated slurry (NPCS) as additive. In order to determine the effects of the slurries in the gypsum, physical, mechanical and thermal properties of the different composite materials (gypsum – polystyrene nanoparticles (PS) or nanocapsules (NPCM)) have been studied. Concentrated slurries from polystyrene nanoparticles without (PSS) and with encapsulated phase change material (NPCS) have been synthesized. Firstly, gypsum blocks made of nanoparticles/hemihydrate with mass ratios ranging from 0.0 to 0.42 have been produced from PSS, in order to determine the optimal weight ratio with the best mechanical/physical characteristics. Then, the thermal gypsum block from NPCM/hemihydrate has been prepared at the selected weight ratio. Although PS and NPCM addition reduces the mechanical properties, all the developed materials satisfied the mechanical European regulation EN 13279-2 which limits the mechanical characteristics of gypsums composites. The gypsum composites with PS nanoparticles presented a reduction of the thermal conductivity, so these materials can be used as insulating material. The gypsum composite with NPCM/Hem = 0.3 had an improvement in the thermal storage capacity of 88.76 % and seems to be a good alternative for applying the thermal energy storage technology in buildings.
Rapid thermalization by adaptive flow reorientation
Authors: Lensvelt R , Speetjens M F M , Nijmeijer H
Published: December 2021

Aim of this paper is the enhancement of scalar transport (heat, chemical species) in flow systems with reorientations of a laminar base flow. Conventional heating/mixing protocols comprise of temporal or spatial periodic reorientations of these base flows to promote fluid mixing. However, thermal homogenisation rates of scalar fields are not necessarily accelerated with these approaches due to the substantial effect of diffusion and/or chemical reactions on heat/chemical transport. In the present study we numerically study heat transport with an adaptive approach for an entire parameter space of fluid and flow properties. Key to the approach is real-time control of the fluid flow based on the scalar field due to an efficient numerical model. Results show that the adaptive approach can significantly enhance heat transport over the conventional periodic heating/mixing approach designed for efficient mixing.
Effect of thickness on the thermo-hydraulic performance of porous volumetric solar receivers with different internal geometries
Authors: Barreto Germilly , Canhoto Paulo , Collares-Pereira Manuel
Published: December 2021

In this work, the effect of thickness on the thermal and hydrodynamic performance of porous volumetric solar receivers made of open-cell silicon carbide (SiC) ceramic foam is investigated using an in-house detailed numerical model. The model is based in a Computational Fluid Dynamics (CFD) technique to solve the volume averaged mass, momentum and energy conservation equations, including the exchange of thermal radiation inside the receiver. A Monte Carlo Ray Tracing (MCRT) method was developed and then used to model the solar radiation transport in the porous media. Two optimised internal geometries (porosity and pores size) of the receiver with adiabatic side-walls are investigated for different thicknesses. Results show that the optimal thickness depends on the porosity and pores size and there is a value from which the thermal efficiency is nearly constant and the pressure drop always increase. It was also found that the thickness should be approximately between 5 and 7 cm for porosity and pores diameter between 0.85 and 0.90 and 3.0 mm and 4.5 mm, respectively, aiming to maximise thermal efficiency by decreasing the transmission losses of solar radiation, and to keep low pressure drop.
Synthesize a Sustainable Supply Chain of Biomass to Electricity via Mathematical Approach
Authors: Hew Chee Yau , Yoon Li Wan , Wan Yoke Kin
Published: December 2021

The huge amount of biomass waste and palm oil mill effluent (POME) generated during oil extraction has prompted the need for a more sustainable framework in waste management. Since oil palm biomass waste is rich in lignocellulosic content, it can be potential to be converted into green energy such as bioelectricity via different pathway of processes such as the thermal conversion pathway and biochemical conversion pathway. This study proposes a mathematical approach to synthesise a sustainable supply chain of biomass to electricity by implementing the combined heat and power (CHP) system in palm oil mill. The optimum pathway of supply chain based on the technical, economical, and environmental aspects is generated. The purpose of this approach is to assists the industry players or owners to make decision in choosing the location of the pre-treatment technology, transportation method, location of power plant and configuration of CHP. A generic superstructure is first developed to achieve the objective. Then, a series of generic mathematical equations will then be formulated based on the pathways demonstrated in the generic superstructure. The mathematical equations involve general mass and energy balance, cost computation and carbon emission. The fuzzy optimisation concept will be adopted in this research to trade-off the conflicting objectives (maximize profit and minimize carbon footprint) in order to generate the optimum pathway. A palm oil-based bioelectricity supply chain case study in Selangor, Malaysia is solved to illustrate the presented approach. According to the optimised result in this case study, a total of 3,753.36 MW of bioelectricity can be generated per year. The result proved that the optimum pathway is feasible by comparing with the existing oil palm biomass-based power plant in Sarawak, where only 375 MW of electricity is generated by oil palm biomass. On the other hand, RM 7.25 million per year of net profit is estimated with a payback period of 2.81 years. Moreover, the CHP system is able to achieve 570 million kg CO2 per year.
Evaluation of the environment impact of extraction of bioactive compounds from Darcyodes rostrata using Deep Eutectic Solvent (DES) using Life Cycle Assessment (LCA)
Authors: Murugan M D , Tee L H , Oh K S
Published: December 2021

Polyphenols, the most abundant and naturally occurring antioxidants, was found to be the highest in Dacryodes rostrata seed as compared to the peel and pulp of the fruit. Growing technologies in the past decades have led to the interest of reviewing and developing environmental-friendly green extraction solvent, as the commonly used conventional solvent imposing various risks to human health and environment. An environmental-friendly extraction technique was established using deep eutectic solvent (DES) as the alternative extraction solvent has been considered. The main objective of this study was to analyse the environmental impact and performance of laboratory processes for phenolic compounds extraction from D. rostrata peel using different solvent, by means of life cycle assessment (LCA). A comparative analysis was carried out to evaluate the environmental impacts caused by both solvents, DES and conventional organic solvent, ethanol. The functional unit (FU) was defined as 104.6 mg of extracted polyphenols, measured as gallic acid equivalents (mg GAE)/g dw of D. rostrata seed used. The variation of environmental impacts between DES and ethanol as a function of optimum process conditions (temperature, time, solid/liquid ratio, and water addition) was evaluated. According to the environmental profile analyzed, the well-developed ethanol exerted lower impact and energy consumptions as compared to the environmental-friendly green solvent, DES. Besides, transport activities and electricity consumptions from the extraction process was identified contributing highest environment impact.