bluuebunny/crossref_metadata_2025 huggingface dataset:
An inverse design method of the acoustic lens
Authors: Gu Chengfu , Yang Zengtao , Wang Hua
Published: October 2021

The traditional forward and inverse diffraction iterative lens design method that replaces the amplitude according to the desired sound field distribution can achieve most sound field distributions under unitary conditions. However, when the sound field distribution we desired contains a sharp plane with abrupt changes, the traditional method will ignore the severe energy loss of the truncated plane. The designed lens will produce a ringing effect, which reduces the quality of the lens. Inspired by the Yang Gu algorithm that can be applied to non-unitary conditions, this paper proposes an acoustic lens design method based on a simulated annealing particle swarm algorithm to overcome the shortcomings of traditional forward and inverse iterative algorithms. The feasibility of this method is verified by designing a lens with a flat-top sound pressure. This paper provides a more widely applicable method in an acoustic lens design.
A two-phase wind speed simulation model considering diurnal and seasonal patterns and its application to adequacy assessment
Authors: Miao Shuwei , Xiong Haoran , Li Dan , Gu Yingzhong
Published: October 2021

Owing to the growing wind penetration, the diurnal and seasonal patterns of wind speed may create a considerable impact on system adequacy. To assess such impact, this paper proposes a two-phase wind speed simulation model considering diurnal and seasonal patterns. The joint wind speed probability distribution of 24-h wind speed is employed to consider the diurnal pattern in the first phase. The optimal season coefficients are proposed to consider the seasonal pattern in the second phase. The optimal season coefficients are obtained by minimizing the difference between the mean value and standard deviation of simulated wind speeds and those of actual wind speeds at each season. With the proposed model, the seasonal adequacy assessment procedure of wind-integrated generation systems considering diurnal and seasonal patterns is developed. The actual wind speed data collected from the wind site in North Dakota are used to justify the accuracy and efficacy of the proposed model. The influences of seasonal pattern, wind turbine quantity, and system peak load on seasonal system adequacy are investigated.
Design, analysis, and experimental investigation of micro-displacement amplification compliant mechanism for micro-transducers
Authors: Iqbal Sohail , Lai YongJun , Shakoor Rana I. , Raffi Muhammad , Bazaz S. A.
Published: October 2021

This paper presents experimental force and buckling analysis of a compliant micro-displacement amplification mechanism fabricated using the commercially available PolyMUMPs process. The proposed mechanism proficiently amplifies displacement, at two output ends, with an optimal amplification factor of 7.2. Buckling analysis revealed that an amplification factor ranging from 2.8 to 11 may be achieved for an input displacement varying from 0.1 to 7.5 µm. Based on the analysis, the optimal value of the amplification factor is found to be 7.2 with an input displacement of 3.5 µm at the operational force of 60 μN having a buckling load factor (BLF) >1. Critical load magnitude is 187 μN having BLF = 1. Buckling occurred when loading exceeded the critical load value, having BLF <1, and the mechanism failed to produce a significant amplification factor. Static analysis showed that stresses produced are within the safe region, and the structural integrity of the mechanism is not compromised having a factor of safety of 1.4. Modal analysis predicted that the natural frequency of the desired mode is 35.47 kHz. Dynamic simulations, under 15 g dynamic load with a frequency range of 30–40 kHz, confirm the possibility of integrating the proposed mechanism with MEMS devices. Parametric optimization comprehends that length and angle are the two major geometric parameters that govern the working range, force, and amplification factor. For input displacements below 1 µm, the amplification factor is even higher, which is highly beneficial for amplifying small displacements. Static, modal, and dynamic analyses of the designed mechanism have been carried out using finite element method based commercial software IntelliSuite®. The experimental results showed that this mechanism can provide the same amplified displacement at two output points and is self-sufficient to be incorporated as an intermediate compliant mechanism for enhancing the output in the case of both static and dynamic micro-devices.
Wear trends of the 12.5 kW HERMeS Hall thruster
Authors: Frieman Jason D. , Gilland James H. , Kamhawi Hani , Mackey Jon , Williams George J. , Hofer Richard R. , Peterson Peter Y.
Published: October 2021

This work presents the results of over 6500 h of wear testing completed during the maturation of the NASA 12.5 kW Hall Effect Rocket with Magnetic Shielding. Erosion of the thruster front pole covers was found to be the primary life-limiting mechanism and exhibits strong dependencies on thruster operating condition and material properties. Specifically, average pole cover erosion rates increased by 76% as discharge voltage decreased from 600 to 300 V and 42%–96% as the magnetic field increased from 0.75 to 1.25 times the nominal value. The cause of both trends is hypothesized to be ion heating from a modified two-stream instability that becomes dominant for 300 V operation and grows with magnetic field strength. Rougher pole covers were observed to have 33% lower average erosion rates than those that were polished due to local surface features that lower the effective angle of attack of eroding ions and the concomitant sputter yields. Alumina pole covers were shown to erode over 250% faster due to the higher sputter yield of alumina relative to graphite. Shifting the cathode upstream of the pole covers reduced average keeper erosion rates by 84% by reducing the view factor to high-energy beam ions. Cathode keeper erosion was also shown to exhibit azimuthal nonuniformities, which resemble the azimuthal oscillations observed in the cathode region. Taken together, these results provide in-depth insights into the life-limiting mechanisms impacting magnetically shielded Hall thrusters.
In-situ plasma treatment of Cu surfaces for reducing the generation of vacuum arc breakdowns
Authors: Saressalo Anton , Kilpeläinen Aarre , Mizohata Kenichiro , Profatilova Iaroslava , Nolvi Anton , Kassamakov Ivan , Tikkanen Pertti , Calatroni Sergio , Wuensch Walter , Djurabekova Flyura
Published: October 2021

High electric fields are present in a rapidly growing number of applications, which include elementary particle accelerators, vacuum interrupters, miniature x-ray sources, and satellites. Many of these applications are limited by the breakdown strength of the materials exposed to electric fields. Different methods have been developed to improve the quality of metal electrode surfaces, aiming to increase their breakdown strength. Not many systematical studies have been performed to provide a proper understanding of what contributes to the correlation between the breakdown strength and the quality of the surface. In this work, we apply a novel method for reducing vacuum arc breakdowns by cleaning the electrode surfaces with O and Ar plasma. The method can be used to alter the surfaces of the Cu electrodes in situ, i.e., without exposing them to air between the measurements. This plasma cleaning treatment is shown to reduce the number of surface impurities and to speed up the conditioning process of the samples under high-voltage pulses. Specifically, the first breakdown field was observed to increase by more than 90% after the plasma cleaning.
Multi-directions pure even harmonic simultaneous generation from planar molecules in linearly polarized laser fields
Authors: Yin Haifeng , Liu Dandan , Zeng Fanju
Published: October 2021

Previous studies have found that pure even harmonics are generated from oriented CO molecules in linearly polarized laser fields. In this work, we demonstrate multi-directions pure even harmonic simultaneous generation from planar molecules in linearly polarized laser fields using the time-dependent density-functional theory. The analysis reveals that pure even harmonic generation depends on the special symmetry of the planar molecule. In the linearly polarized laser field, it is found that only when the planar molecules have reflective symmetry direction and the molecules perpendicular to the reflective symmetry direction do not have reflection symmetry can the planar molecules generate pure even harmonics along such reflective symmetry direction. When the laser polarization is perpendicular to the planar molecule, if the molecule has several these directions of such reflection symmetry, pure even harmonics will be simultaneously generated along these symmetrical directions. Moreover, when the laser polarization is along the molecular plane and perpendicular to the direction of one such reflection symmetry, even harmonic is also generated along this reflection symmetry direction, whereas odd harmonic is generated along the direction of laser polarization. The phenomenon exists in all polyatomic planar molecules with such reflection symmetry.
Optimum design of a supercapacitor charged by a photovoltaic module
Authors: Xiao Juying , Fu Tong , Chen Jingyi , Su Shanhe , Wang Junyi , Chen Jincan
Published: October 2021

A solar-driven charging device composed of a photovoltaic module and a supercapacitor is proposed. Based on the equivalent circuit model of the device, the current–voltage relationship of the hybrid system is established. The energy conversion and storage efficiency and the energy stored in the supercapacitor as functions of the charging time have been derived. The advantage of the theoretical model is that the effects of the series resistance, parallel resistance, solar irradiance, and operating temperature on the charging performance of the supercapacitor can be evaluated. The optimal relationships between the capacitance of the supercapacitor and the charging time at different external conditions, i.e., the optimally matching conditions of the supercapacitor, have been provided. Results show that the proposed theoretical analysis method is capable of efficiently evaluating the performance of photo-supercapacitors under given parameters of practical photovoltaic systems. The proposed model may pave the foundation for the future development of supercapacitors driven by commercial PV modules.
Nonlinear wave propagation in dense vapor of Bethe–Zel'dovich–Thompson fluids subjected to temperature gradients
Authors: Chandrasekaran N. B. , Mercier B. , Colonna P.
Published: October 2021

Flows of fluids made of complex organic molecules exhibit unconventional fluid dynamic behavior in the vapor phase if their thermodynamic state is close to that of the vapor–liquid critical point. If the molecule is sufficiently complex, this thermodynamic domain is characterized by negative values of the fundamental derivative of gasdynamics Γ, the fluid is called Bethe–Zel'dovich–Thompson (BZT) fluid, and atypical phenomena, such as rarefaction shockwaves, are theoretically admissible. The nature of the steepening of nonlinear waves in dense vapor flows of organic fluids evolving in this thermodynamic region can be significantly affected by the presence of temperature gradients in the flow. This study investigates the evolution of finite-amplitude acoustic waves in these conditions. The steepening of the wavefront is analyzed using the wavefront expansion technique, and the deformation of the wavefront is simulated numerically by solving the Westervelt equation. The results of simulations of wave propagation in dense vapors indicate that, though Γ governs the nature of steepening waves, local gradients in sound speed and density can alter the rate of steepening and can enhance or delay shock formation in the medium, a result relevant also to the envisaged experiments aimed at proving the existence of nonclassical gasdynamics phenomena in BZT vapors.
The effects of nitroxide structure upon 1H Overhauser dynamic nuclear polarization efficacy at ultralow-field
Authors: Fehling Paul , Buckenmaier Kai , Dobrynin Sergey A. , Morozov Denis A. , Polienko Yuliya F. , Khoroshunova Yulia V. , Borozdina Yulia , Mayer Philipp , Engelmann Jörn , Scheffler Klaus , Angelovski Goran , Kirilyuk Igor A.
Published: October 2021

The efficacy in 1H Overhauser dynamic nuclear polarization in liquids at ultralow magnetic field (ULF, B0 = 92 ± 0.8 µT) and polarization field (Bp = 1–10 mT) was studied for a broad variety of 26 different spin probes. Among others, piperidine, pyrrolidine, and pyrroline radicals specifically synthesized for this study, along with some well-established commercially available nitroxides, were investigated. Isotope-substituted variants, some sterically shielded reduction-resistant nitroxides, and some biradicals were included in the measurements. The maximal achievable enhancement, Emax, and the radio frequency power, P1/2, needed for reaching Emax/2 were measured. Physico-chemical features such as molecular weight, spectral linewidth, heterocyclic structure, different types of substituents, deuteration, and 15N-labeling as well as the difference between monoradicals and biradicals were investigated. For the unmodified nitroxide radicals, the Emax values correlate with the molecular weight. The P1/2 values correlate with the spectral linewidth and are additionally influenced by the type of substituents neighboring the nitroxide group. The nitroxide biradicals with high intramolecular spin–spin coupling show low performance. Nitroxides enriched with 15N and/or 2H afford significantly higher |Emax| and require lower power to do so, compared to their unmodified counterparts containing at natural abundance predominantly 14N and 1H. The results allow for a correlation of chemical features with physical hyperpolarization-related properties and indicate that small nitroxides with narrow spectral lines have clear advantages for the use in Overhauser dynamic nuclear polarization experiments. Perdeuteration and 15N-labeling can be used to additionally boost the spin probe performance.
Silver nanoparticle array on weakly interacting epitaxial graphene substrate as catalyst for hydrogen evolution reaction under neutral conditions
Authors: Shtepliuk I. , Pliatsikas N. , Jian J. , Ben Sedrine N. , Iakimov T. , Sarakinos K. , Ivanov I. G. , Sun Jianwu , Yakimova R.
Published: October 2021

The paucity of research on hydrogen evolution reaction (HER) under neutral conditions, which is a more sustainable way to produce H2 compared to acidic and alkaline HER, encourages the development of efficient catalytic materials and devices and deeper investigation of the mechanisms behind neutral HER. We present an electrode concept for facilitating HER under neutral conditions. The concept entails the use of annealing-reshaped silver (Ag) nanoparticle array on monolayer epitaxial graphene (MEG) on 4H-SiC. Measurements of HER performance show more positive onset potential of the cathodic HER for Ag-decorated MEG compared to that for pristine MEG, indicating improved water dissociation at Ag/MEG electrodes. Complementary morphological characterization, absorption measurements, and Raman mapping analysis enable us to ascribe the enhanced catalytic performance of electrodes decorated with 2 nm thick annealed Ag on the synergetic effect originating from simultaneous water reduction on circular Ag nanoparticles of 31 nm in diameter and on compressively strained Ag-free graphene regions. The overall results pave the way toward development of stable van der Waals heterostructure electrodes with a tunable metal–carbon interaction for fast HER under neutral conditions.
Laser-induced transverse voltage effect in c-axis inclined CuCr0.98Mg0.02O2 thin films with dominant phonon thermal conductivity
Authors: Hu Y. D. , Li Y. , Wu H. R. , Tang Y. Y. , Fan K. , Liu B. , Yu L.
Published: October 2021

CuCr1−xMgxO2 (x = 0 and 0.02) epitaxial thin films were prepared on 5°/10° vicinal cut α-Al2O3 (000l) substrates using pulsed laser deposition. The laser-induced thermoelectric voltage (LITV) effect in these inclined delafossite thin films was observed for the first time. The thin films were characterized by resistivity temperature measurement and atomic force microscopy. Because of the enhanced resistivity anisotropy and high carrier concentration in the ab-plane owing to Mg doping, the 10°-tilted CuCr0.98Mg0.02O2 film exhibits an evident LITV signal with a maximum transverse thermoelectric voltage of 156 mV. Thermal conductivity results indicate that CuCr1−xMgxO2 (x = 0 and 0.02) films have a dominant phonon thermal conductivity, which may contribute to a long decay time for the LITV signal. These results indicate potential for future transverse thermoelectric applications based on transparent conductive oxides.
Computational fluid dynamics analysis of droplet generation in microfluidic multi-cell coupled systems
Authors: Li Hongxia , Qiao Du , Ren Fuzheng , Li Honglin , Zhu Weiping , Zhao Danyang , Wang Minjie
Published: October 2021

Multi-cell coupled droplet generator systems have been used for high-throughput production of microdroplets. However, the coupling effects of intercellular geometry and flow parameters can produce complex hydrodynamic phenomena that affect droplet generation processes and properties. In this study, a computational model of droplet generation in a multi-cell parallel geometry was developed based on the phase field method, and the droplet formation process and hydrodynamic properties in a multi-cell coupled droplet generator were investigated. The coupling effects of flow parameters (e.g., capillary number, continuous and dispersed phase flow rates and flow ratios) on the droplet generation process were systematically analyzed to investigate droplet characteristics and mechanisms in the multi-cell coupled droplet generator system. The causes of synchronous and asynchronous droplet generation patterns in multi-cell coupled systems are also analyzed over a range of capillary numbers. It is found that the droplet generation frequency increases with increasing continuous-phase flow velocity while the size decreases; the droplet size is smaller and the frequency is larger in multi-cell coupled systems than in stand-alone systems at the same flow velocity ratio; the difference between synchronous and asynchronous droplet generation patterns is closely related to the geometric coupling of continuous-phase flow channels and the uneven flow field distribution. This work will provide useful insights into droplet generation in multi-cell coupled systems and provide useful guidance for the structural design of multi-cell coupled systems.
Heat sink avalanche dynamics in elastocaloric Cu–Al–Ni single crystal detected by infrared calorimetry and Gaussian filtering
Authors: Capellera Guillem , Ianniciello Lucia , Romanini Michela , Vives Eduard
Published: October 2021

The physics behind the cooling process occurring in an elastocaloric Cu–Al–Ni wire during the martensite to austenite transition after stress release is studied. A previous experiment using infrared imaging determined the temperature map evolution of the sample surface and obtained the qualitative evolution of heat sinks by reversing the Fourier heat equation. The results were only qualitative due to the data smoothing algorithm that was used to correct the experimental noise. We analyze the original data by using a more appropriate Gaussian filter to reject the noise without smoothing the sharp martensite-austenite interfaces. Results show a much better spatial resolution that enables us to obtain new physical variables characterizing the discontinuous, avalanche-like, cooling process: the sink width, the sink cooling power, and the sink velocity.
Friction factor for steady periodically developed flow in micro- and mini-channels with arrays of offset strip fins
Authors: Vangeffelen A. , Buckinx G. , Vetrano M. R. , Baelmans M.
Published: October 2021

In this work, the friction factor for steady periodically developed flow through micro- and mini-channels with periodic arrays of offset strip fins is analyzed. The friction factor is studied numerically on a unit cell of the array for Reynolds numbers ranging from 1 to 600, and fin height-to-length ratios below 1. It is shown that the friction factor correlations from the literature, which primarily focus on larger conventional offset strip fin geometries in the transitional flow regime, do not predict the correct trends for laminar flow in micro- and mini-channels. Therefore, a new friction factor correlation for micro- and mini-channels with offset strip fin arrays is constructed from an extensive set of numerical simulations through a least squares fitting procedure. The suitability of this new correlation is further supported by means of the Bayesian approach for parameter estimation and model validation. The correlation predicts an inversely linear relationship between the friction factor and the Reynolds number, in accordance with our observation that a strong inertia regime prevails over nearly the entire range of investigated Reynolds numbers. Yet, through a more detailed analysis, also the presence of a weak inertia regime and a transitional regime is identified, and the transitions from the strong inertia regime are quantified by means of two critical Reynolds numbers. Finally, the new correlation also incorporates the asymptotic trends that are observed for each geometrical parameter of the offset strip fin array, and whose origins are discussed from a physical perspective.
Probabilistic computing with p-bits
Authors: Kaiser Jan , Datta Supriyo
Published: October 2021

Digital computers store information in the form of bits that can take on one of two values 0 and 1, while quantum computers are based on qubits that are described by a complex wavefunction, whose squared magnitude gives the probability of measuring either 0 or 1. Here, we make the case for a probabilistic computer based on p-bits, which take on values 0 and 1 with controlled probabilities and can be implemented with specialized compact energy-efficient hardware. We propose a generic architecture for such p-computers and emulate systems with thousands of p-bits to show that they can significantly accelerate randomized algorithms used in a wide variety of applications including but not limited to Bayesian networks, optimization, Ising models, and quantum Monte Carlo.
Integrated epsilon-near-zero antenna for omnidirectional radiation
Authors: Liu Zhenyu , Zhou Ziheng , Li Yang , Li Yue
Published: October 2021

Antennas with omnidirectional radiation of electromagnetic wave have wide applications in sensing, positioning, and wireless communications. Here, we investigate the potentials of using epsilon-near-zero (ENZ) metamaterial to realize omnidirectional radiation with high degrees of freedom. We propose an omnidirectional antenna based on an ENZ cavity integrated in printed circuits board (PCB). By taking advantage of ENZ behavior, the ENZ antenna can decouple the radiation patterns and the operating frequency while maintaining the omnidirectional radiation characteristic. Based on the omnidirectional ENZ antenna element, a parallel-fed array is realized based on the low-cost PCB process. The integrated ENZ antenna array exhibits the capability of engineering the omnidirectional radiation flexibly, such as beam scanning and beam intensity control for practical applications.
Observation of structural distortion and topological Hall effect in noncollinear antiferromagnetic hexagonal Mn3Ga magnets
Authors: Song Linxuan , Ding Bei , Li Hang , Lv Senhao , Yao Yuan , Zhao Dongliang , He Jun , Wang Wenhong
Published: October 2021

The structure, magnetism, and topological transport properties of noncollinear antiferromagnetic hexagonal Mn3Ga magnets have been investigated. Structural analyses reveal that as the temperature decreases, hexagonal Mn3Ga shows a Jahn–Teller-like distortion at T = 120 K. The distortion results in the anisotropy decreasing with decreasing temperature. Positive magnetoresistance is observed, and humps occur at low magnetic fields, which can be understood by breaking the ordered antiferromagnetic configuration by an external field and the spin-dependent scattering mechanism, respectively. In addition, a large topological Hall effect is observed in Mn3Ga, which originates from the noncollinear triangular magnetic configuration with slight distortion. The results are discussed in the context of coupling with noncollinear spin canting, lattice distortion, and topological transport.
Chronic pain and cardiovascular disease prevention in primary care: a review of Australian primary health network needs assessments
Authors: Walker Pippy , Cornell Samuel , De Morgan Simone , Bonner Carissa , Blyth Fiona M.
Published: October 2021

Objective Chronic pain and cardiovascular disease (CVD) have a high disease burden. This research aimed to understand whether Australian primary health networks (PHNs) are recognising the need for the prevention of these conditions by investigating what local health and service issues have been identified. Methods Separate sets of needs assessments were analysed for chronic pain and CVD for all 31 PHNs using a document analysis approach. Framework analysis was undertaken to ascertain the types of health and service issues, prevention-related issues and supporting data sources identified, as well as to quantify the number of PHNs identifying these issues. Results Fewer PHNs identified health issues for chronic pain (n = 13) compared with CVD (n = 30), with the most common being disease prevalence and burden supported by National Health Survey data. Service issues were identified by fewer than half the PHNs (n = 13 for each disease), which were largely informed by stakeholder consultation and related to service integration, service accessibility and health professional training. Prevention-related issues were frequently identified for CVD (n = 26), but not chronic pain (n = 3). Conclusions This paper highlights the need for a greater focus on chronic pain- and CVD-related issues by PHNs. This could be supported nationally by recognising chronic pain and risk factors in national datasets and PHN performance frameworks, and locally via greater stakeholder consultation to inform PHN population health planning. What is known about the topic? Chronic pain and CVD are the two leading causes of total disease burden in Australia. PHNs are well positioned to address prevention locally through population health planning, supporting primary healthcare providers, health care integration and coordination and commissioning necessary services. What does this paper add? This paper highlights gaps in data availability, the proportion of PHNs identifying local service issues for both chronic pain and CVD and health- and prevention-related issues for chronic pain. What are the implications for practitioners? Although PHNs are constrained by government priorities and funding, greater stakeholder consultation is one potentially promising strategy to overcome local data gaps to identifying and prioritising chronic pain and CVD prevention.
Designing better nestboxes: double-walled and pale proves coolest under the sun
Authors: Ellis Murray V. , Rhind Susan
Published: October 2021

Context Fauna nestboxes are used for conservation, research and mitigation against tree hollow/cavity loss. Scant attention has been given to the microclimate inside boxes until recently, with concern that nestboxes may be ineffective or a thermal trap because of high internal temperatures during summer. Aim Our study used construction design principles to guide modifications to nestboxes to reduce maximum temperatures inside boxes. Methods Five trials were undertaken, and modifications included addition of thermal mass, creation of a double wall system and painting the box and/or outer wall white. Nestboxes were placed in full sun. Key results The internal temperature difference from ambient between the worst (unpainted box) and the best box design was around 7°C at 30°C, and 9.5°C at 40°C. Painting boxes white had a marked impact on internal temperatures, but the single modification giving most protection from heat gain was construction of a ventilated double wall. This created a shaded air space around the internal box. Painting the outer layer white further improved insulation, and painting both the box and outer layer gave the best result. Conclusion Double-walled, pale nestboxes can provide significant protection from solar heat. Implications  Adding an air space to insulate a nestbox has considerable advantages over alternatives − it contributes little weight (compare using denser wood/materials); avoids environmental issues associated with insulators such as polystyrene or foil batts; is inexpensive; is easy to retrofit a second layer around existing boxes and it should improve nestbox longevity as the outer layer protects the inner box from weathering.
Synapse development is regulated by microglial THIK-1 K
+
channels
Authors: Izquierdo Pablo , Shiina Hiroko , Hirunpattarasilp Chanawee , Gillis Grace , Attwell David
Published: October 2021

Significance

Microglia are the brain’s resident immune cells, surveying the brain with motile processes, which can remove pathogens but also prune unnecessary junctions between the neurons (synapses). A potassium channel, THIK-1, in the microglial membrane allows efflux of potassium from these cells and thereby regulates their membrane voltage as well as their process motility and release of inflammatory mediators. Here, using THIK-1–blocking drugs and THIK-1–deficient mice, we demonstrate that THIK-1 controls removal of synaptic material by microglia, which reduces the number of functional synapses in the developing brain.
The axis of professionalization
Authors: Djovčoš Martin , Šveda Pavol
Published: October 2021

Using the results of two surveys conducted by the present authors, this paper examines translators’ and interpreters’ behaviour in the translation market and factors that influence it in (Slovak) society. In keeping with the familiar fact that not all translators are alike, we believe that empirically measurable factors enable us to observe behavioural patterns among translators and interpreters that are distinguishable along an axis of specialisation and an axis of professionalisation. The authors conducted two separate surveys involving 550 translators and interpreters – including literary translators, court translators and interpreters, translators of technical texts, audiovisual translators, institutional interpreters, and freelance translators – who worked across Slovakia’s market spectrum. In the analysis of the survey results, we found that, among other things, the level of professionalisation played a crucial role in translators’ decision-making processes within the broader social and professional context. In line with Toury’s (1995, 55) definitions of the norm, we hoped to “distinguish regularity of behaviour in recurrent situations of the same type” according to certain factors, including the degree of professionalisation and age, education, and type of translatorial activity.
Topological hybrid semimetal phases and anomalous Hall effects in a three dimensional magnetic topological insulator
Authors: Chen M N , Chen W C , Zhou Yu
Published: October 2021

In this work, we propose a ferromagnetic Bi2Se3 as a candidate to hold the coexistence of Weyl- and nodal-line semimetal phases, which breaks the time reversal symmetry. We demonstrate that the type-I Weyl semimetal phase, type-I-, type-II- and their hybrid nodal-line semimetal phases can arise by tuning the Zeeman exchange field strength and the Fermi velocity. Their topological responses under U(1) gauge field are also discussed. Our results raise a new way for realizing Weyl and nodal-line semimetals and will be helpful in understanding the topological transport phenomena in three-dimensional material systems.
Fragmentation of stable and neutron-rich 12-16C into boron fragments at approximately 240 MeV/nucleon *
Authors: Jin Shu-Ya , Sun Ya-Zhou , Wang Shi-Tao , Sun Zhi-Yu , Zhang Xue-Heng , Chen Zhi-Qiang , Mei Bo , Zhao Yi-Xuan , Tang Shu-Wen , Yu Yu-Hong , Yan Duo , Fang Fang , Zhang Yong-Jie , Ma Shao-bo , Liu Xiang-Man , Han Rui
Published: October 2021

The elemental fragmentation cross sections of boron fragments produced by stable and neutron-rich 12-16C beams with a carbon target were systematically measured at an incident beam energy of approximately 240 MeV/nucleon. The measured cross sections were found to increase as the projectile mass number increases. The observed feature is explained qualitatively based on the abrasion-ablation two-stage reaction model and is compared quantitatively with predictions from various reaction models, including empirical and statistical models. All models agree with the measured cross sections within a factor of 2.
Fabrication of thermally conductive polymer composites based on hexagonal boron nitride: recent progresses and prospects
Authors: Zhang Yi , Niu Haoting , Liyun Wu , Wang Nanyang , Xu Tao , Zhou Zhengyang , Xie Yufeng , Wang Han , He Qian , Zhang Kai , Yao Yagang
Published: October 2021

Hexagonal boron nitride (h-BN) and its nanomaterials are among the most promising candidates for use in thermal management applications because of their high thermal conductivity, thermal stability, and good electric insulation, and when used as the conductive fillers, they enhance the overall properties of polymer composites. In this review, the basic concepts of h-BN are introduced, followed by the synthesis of BN nanotubes and BN nanosheets. Then, various novel methods to fabricate h-BN polymer composites with improved thermally conductive paths are discussed. They can be classified into two categories: dispersion and compatibility reinforced and structure formation. In addition, the thermal conducting mechanisms of h-BN composites are proposed. Finally, the advantages and limitations of aforementioned strategies are summarized.
The Effectiveness of Dual-Staining Immunohistochemistry in the Detection of Mantle Cell Lymphoma in the Bone Marrow
Authors: Obiorah Ifeyinwa E , Wang Hao-Wei , Ma David , Martin Eddie , Wilson Wyndham H , Braylan Raul
Published: October 2021

Objectives

Immunohistochemistry (IHC) is a useful method for mantle cell lymphoma (MCL) detection in the bone marrow (BM). However, recognition of the neoplastic B cells can be challenging, especially when there is low-level disease.

Methods

We examined BM from 105 patients with MCL. IHC was performed using cyclin D1/CD79a and PAX5/CD5 dual stains, which were compared with single stains that included CD20, CD79a, cyclin D1, and CD5 and with multiparameter flow cytometry (FC).

Results

Based on the FC data, the overall sensitivity of the dual IHC stains was 95.6%. Both dual IHC stains showed better efficacy for detecting MCL cells compared with the aggregated single stains (P = .012). While three cases were positive by FC analysis but negative for dual staining, four cases showed cells positive for cyclin D1/CD79a and PAX5/CD5 dual staining that were not detected by FC. Two of these latter cases were in patients with minimal or focal disease involvement.

Conclusions

Cyclin D1/CD79a and PAX5/CD5 dual IHC staining is an efficient procedure for the detection of MCL in the marrow and is particularly helpful in low-level or focal involvement by MCL. This approach can be particularly useful when marrow aspirates are inadequate or unavailable.
Critical Enough
Authors: Tamarkin Elisa
Published: October 2021

The essay is a reflection on value and validity in criticism in light of Matthew Arnold’s essay on the function of criticism, plus an anecdote about a graduate student who bothered to complete her dissertation after nearly half a century, finding it worthwhile even then. It asks how we might keep these old projects of ours meaningful in unfolding circumstances and what patience can do; also, how critical discrimination might address the needs of the present time by suggesting a different way of proceeding, a sort of procedural change, with recourse to the criticism of Alain Locke, John Dewey, and F. R. Leavis.
177 Pedicled Or Skeletonized Bilateral Internal Mammary Artery Harvesting - A Meta- Analysis and Trial Sequential Analysis
Authors: Iddawela S , Mellor S L , Zahra S A , Khare Y , Harky A
Published: October 2021

Objective

There is varying evidence on the role of skeletonization of internal mammary artery in reducing the risk of sternal wound infections and ischemia following bilateral internal mammary artery grafting. We opt to compare post-operative clinical outcomes of skeletonized bilateral internal mammary artery versus pedicled bilateral internal mammary artery harvesting in patients undergoing coronary artery bypass surgery.

Method

A comprehensive electronic search was conducted using PubMed/MEDLINE, Scopus, EMBASE, Cochrane database and Google Scholar from inception until 15th June 2020. All studies directly comparing skeletonized and pedicled bilateral internal mammary artery harvesting were included. Meta-analysis and trial sequential analysis was conducted.

Results

Ten studies consisting of 3728 patients (2098 patients with skeletonized bilateral internal mammary artery grafting and 1630 patients with pedicled bilateral internal mammary artery grafting) were included. Pooled effects analysis and trial sequential analysis reported significantly lower risk of sternal wound infection with skeletonized bilateral internal mammary artery harvesting (OR 0.32, 95% CI 0.20 – 0.51, p < 0.00001). S-BIMA may be associated with lower late mortality, but more information is required to confirm this.

Conclusions

Skeletonization reduces the risk of sternal wound infections by preserving vasculature as much as possible. This makes it an important technique for use in bilateral internal mammary artery grafting for high-risk patients.
717 Roux-En-Y Versus Single Loop Reconstruction in Pancreaticoduodenectomy: A Systematic Review and Meta-Analysis
Authors: Mobarak S , Tarazi M , Davé M , Varley R , Stott M , Baltatzis M , Satyadas T
Published: October 2021

Aim

Post-operative pancreatic fistula (POPF) and delayed gastric emptying (DGE) both remain problematic complications following pancreaticoduodenectomy. This systematic review and meta-analysis evaluates whether Roux-en-Y compared to a single loop reconstruction in pancreaticoduodenectomy significantly reduces rates of these complications.

Method

A systematic review and meta-analysis were conducted according to the PRISMA guidelines by screening EMBASE, MEDLINE/PubMed, CENTRAL and bibliographic reference lists for comparative studies meeting the predetermined inclusion criteria. Post-operative outcome measures included: POPF, DGE, bile leak, operating time, blood loss, need for transfusion, wound infection, intra-abdominal collection, post-pancreatectomy haemorrhage, overall morbidity, re-operation, overall mortality, hospital length of stay. Pooled odds ratios or mean differences with 95% confidence intervals were calculated using either fixed- or random-effects models.

Results

Fourteen studies were identified including four randomized controlled trials (RCTs) and 10 observational studies reporting a total of 2 031 patients. Data synthesis showed no statistically significant difference between the two groups in any of the outcome measures except operating time, which was longer in those undergoing Roux-en-Y reconstruction.

Conclusions

Roux-en-Y is not superior to single loop reconstruction in pancreaticoduodenectomy but may prolong operating time. Future high-quality randomized studies with appropriate study design and sample size power calculation may be required to further validate this conclusion.
821 Comparative Effectiveness of Interventions to Reduce Ileus After Colorectal Surgery: A Network Meta-Analysis
Authors: Ashcroft J , Singh A A , Ramachandran B , Habeeb A , Hudson V , Meyer J , Simillis C , Davies R J
Published: October 2021

Aim

Several treatment strategies for post-operative ileus have been evaluated in randomised controlled trials. This network meta-analysis aimed to explore the relative effectiveness of these different therapies on their impact on ileus outcome measures.

Method

A systematic review was conducted to identify randomised controlled trials reported up to 23rd April 2020. Indirect comparisons of all regimens were simultaneously compared using random-effects network meta-analysis.

Results

A total of 48 randomised controlled trials, reporting any combination of five different outcome measures of time to flatus, stool, and solid diet tolerance, or nasogastric tube post-operative insertion, or length of stay following colorectal surgery were identified. In this network meta-analysis, early feeding was ranked first for time to solid diet tolerance (Mean Difference (hours) -58.845 CrI (-73.414, -43.150; rank 1 p = 0.960) and length of hospital stay (Mean Difference (hours) -2.326; CrI -3.510, -1.184; rank 1 p = 0.465) with high probability of first rank in the remainder of measures. Epidural analgesia was ranked first for time to flatus (Mean Difference (hours) -18.882; CrI -33.673, -3.435; rank 1 p = 0.286) and time to stool (Mean Difference (hours) -26.054; 95% CrI -66.417, 15.645; rank 1 p = 0.268).

Conclusions

This network meta-analysis identified early feeding as the most efficacious therapeutic to reduce post-operative ileus in patients undergoing colorectal surgery. High quality studies of the efficacious therapeutics to reduce ileus following colorectal surgery highlighted in this review are required with established core outcome measures of gastrointestinal mobility.
62 Evaluation of Laparoscopic Cholecystectomy with the help of AI-Video Analytics Platform
Authors: Gendia A , Korambayil S , Cota A , Finlay I , Clarke M , Al-Ardah M , Clark J
Published: October 2021

Aim

This report aims to evaluate the use of an AI video analytics platform in laparoscopic cholecystectomy (LC) based on the achievement of the critical view of safety (CVS) and to assess its ability to correctly comment on CVS.

Method

Touch surgery video platform, an AI-video based analytic tool, was screened for laparoscopic cholecystectomy in our institute and analysed from April 2019 till October 2020. Data collected by the AI included identification of the critical view of safety and time needed to achieve CVS. A reviewer graded the LC according to Nasser grading and evaluated the ability of AI to identify the CVS.

Results

66 LC were included from our video database. CVS was achieved in only 56% (37/66) in all LC videos included. Mean time spent to attend CVS from start of dissection of Calot’s triangle 16.8 (±13.6) mins. 26 (39.4%) LCs were Nasser grade 2 and 20 (30.3%) each were grade 1 and grade 3. There was no significant difference between number of CVS obtained between all grades. Time spent to achieve CVS from dissecting Calot’s triangle were the longest in grade 3 LCs (28.4±17.4 mins) with significant difference between all 3 grades. Finally, the platform correctly commented on CVS in 92.4% of the all LC videos.

Conclusions

AI video analytics can provide a useful tool to assess laparoscopic cholecystectomies and the critical view of safety. Additionally, more studies should explore the use of the platfrom and integrate the results with the clinical outcomes.
326 Resorbable Composite Materials for Fracture Fixation
Authors: Baljer B , Melo P , German M , Dalgarno K
Published: October 2021

Introduction

Titanium-based fracture fixation devices often necessitate removal in the maxillofacial region. Resorbable composite implants negate the need for a revision operation; however, concurrent devices either possess a prolonged degradation profile or bioactivity, resulting in undesirable bone deposition. To that end, a novel, fast-resorbing, non-bioactive composite material is proposed, which still possesses an osteoinductive potential, thereby aiding fracture healing.

Method

Three bioglasses were available (NCL1-3) as filler material. NCL2 was selected and different concentrations (5%; 20%) were added to reinforce medical grade poly(lactic-co- glycolide) (PLGA). The final compression moulded samples underwent material characterisation and an 8-week degradation assay.

Results

No significant difference was found between the cytotoxicity of the glasses and both the positive (apatite wollastonite) and negative (absence of glass) controls in relation to mesenchymal stem cells or osteoblasts. pH and weight change analyses showed an increased rate of degradation with an increase in glass concentration. Although reinforcement with NCL2 did not increase the mechanical properties of the polymer, no significant difference was present between the mechanical properties of the composites, and, as made, both 5% and 20% composites had flexural strengths of 13MPa±5, which did not decrease significantly during degradation.

Conclusions

NCL1-3 are non-toxic in the context of fracture healing. The PLGA/NCL2 composite is not suitable for fracture fixation as produced currently, due to increased polymer degradation and lower mechanical properties. However, 20% compositions are recommended for future research, as they would hypothetically provide a superior osteoinductive response without significantly lowering the mechanical properties of the composite.
1244 The TAL Suction Retractor: A Simple Technique for Visualising the Transverse Acetabular Ligament (TAL) During Total Hip Replacement (THR) Surgery
Authors: Murphy B , Pollock R , Ramchurn S , Hurson C
Published: October 2021

Introduction

The transverse acetabular ligament (TAL) is an anatomical landmark that is of particular use during primary total hip replacements (THR). Visualisation is important to aid the orientation of the acetabular cup and it is a structure that can be identified in virtually every primary hip replacement surgery. We introduce a simple technique to facilitate this.

Method

A thoracic suction catheter is taped to the distal end of a blunt Hohmann’s retractor with two steristrips wrapping around the catheter and retractor leaving approximately 1-1.5cm of retractor exposed. Our preference is for a thoracic suction catheter with side holes and a proximal end which allows direct connection with the tip of the Yankauer suction. The blunt Hohmann’s retractor is used as the inferior acetabular retractor in the usual way, placed inferior to the transverse acetabular ligament, resting on the posterior ischial surface. The catheter suction tip should lie just under the TAL, in the most dependant point of the wound.

Results

The TAL suction catheter can be used continuously or intermittently to facilitate visualisation of the TAL during reaming, trialling, and acetabular cup placement. The TAL suction retractor provides suction in the most dependant point of the surgical wound, preventing unnecessary movement and facilitates a clutter-free surgical field leading to more streamlined and efficient surgery with potential reduced operative times.

Conclusions

The transverse acetabular ligament (TAL) suction retractor is a simple improvised surgical tool that makes it easier to visualise the TAL during acetabular preparation in total hip replacements.