bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of MOOC in Physical Education Teaching Mode Under the Background of Big Data
Authors: Wang Linhan , Wang Ming
Published: February 2021

With the continuous development of network technology, the application of Internet technology in education mode is becoming more and more closely. MOOC education method that should be applied to online teaching platform is called the current mainstream hot topic. Applying big data technology to online teaching platform can effectively solve the problems of numerous and confusing teaching resources, difficult user selection, weak management of online learning process and teaching The resources can not be efficiently utilized, and the user’s sense of role is missing. The application of big data technology in network teaching has, to a certain extent, subverted the traditional teaching system, changed the teaching mode of unified place, unified time and unified content. According to the analysis results of big data, learners can flexibly choose the time and place of class according to their own needs and characteristics, and carry out personalized and customized teaching resource learning. These decisions are not Subjective, but through the analysis of big data, on the basis of objective and reliable data, the decision is made. In this paper, through a comparative experiment of two classes of students in Physical Education in a university, the results of big data analysis show that the application of MOOC in physical education teaching mode can improve students’ learning enthusiasm to a certain extent, and the satisfaction degree of students to MOOC is as high as 92%; it can also assist students to improve their academic performance, and the average score of classes using MOOC is 10 points higher than that under the traditional education mode about.
MGCN: Graph Convolutional Network for Drug Molecular Screening
Authors: Wang Shoujin , Zhu Yongyuan , Liu Jifei
Published: February 2021

The intersection of drug research and development and neural network research is getting closer, new methods and new technologies are emerging one after another, using neural network to improve the efficiency of drug research and development, and rapidly innovate the treatment of diseases. In drug development, one target protein corresponds to multiple drug molecules. In order to save the time and cost of new drug development, virtual screening of key steps in new drug development is studied. A virtual screening model for drug molecules is proposed, and the graph convolutional neural network is used to classify drug molecules to achieve the purpose of preliminary screening. The graph convolutional network model is constructed based on DGL and combined with cross-entropy and fully connected networks. The model is carried out by experimental means analysis. The experimental results show that the graph neural network can complete the classification task of drug molecules. Through the verification of molecular docking software, the screened molecules are real and effective, reducing the time spent on virtual screening, and it has become an inspiration for further exploration of graph neural networks in drug development.
A simple note on the growth rate of Covid-19 in Indonesia based on a curve trend generated by a spreadsheet
Authors: Anggaryani M , Prastowo T , Madlazim  , Supardiyono  , Asnawi
Published: February 2021

This preliminary study is aimed at examining the growth rate of Covid-19 pandemic in Indonesia in a framework of a nationwide issue. Using a spreadsheet, this study generates time-series development of the disease from its early stage in March to the late of July 2020. The study focuses on the analysis of three indicators, namely the number of people confirmly infected, recovered, and dead, daily reported by the authorities to monitor the severe outbreak. A number of groups of people, such as people under observation (ODP), suspected (PDP), and with no symptoms (OTG) are excluded from selected indicators due to difficulties in detection of people accounted for in each group. Cases confirmed are given by the results ofPolymerase Chain Reaction(PCR)testsfrom swab sampled and are not determined by those ofrapid tests. The data were collected from The Ministry of Health, The Republic of Indonesia and National Agency for Disaster Relief (BNPB). We report findings on the effectiveness of a PSBB policy that includes physical and social distancing during different stages and the possible roles of four connected parameters, namely community resilience, goverment control, medical access and treatment, and economy recovery. From the data acquired and presented in separate curves, we analyse the growth rate of Covid-19 in Indonesia. Regarding distinct trends of the curves with an indication of a continuous transmission, we conclude that combined factors, involving ineffective implementation of the policy and a low community resilience make the infectious disease outbreak uncontrollable in some sense.
Study of Steady State Heat Conduction in Composite Layer by Linear Triangular Finite Element
Authors: Riupassa Robi Dany , Waris Abdul , Viridi Sparisoma , Basar Khairul , Novitrian  , Abdillah Habibi
Published: February 2021

Finite element method with linear triangular shape function was used to numerically investigate steady state heat conduction in composite layer. This method divides each layer into a number of small elements. By defining elements, local node, global node, and temperature boundary conditions, an element coefficient matrix can be formed. Element coefficient matrix needs to be assembled to form a global coefficient matrix. The solution of the global coefficient matrix will provide the temperature value at each node. In this research, variations of the thermal conductivity value and temperature boundary conditions are applied. The results of the study will show the effect of different thermal conductivity value against temperature gradient.
Comparative Study on Fuel Assembly of Modular Gas-cooled Fast Reactor using MCNP and OpenMC Code
Authors: Raflis H. , Ilham M. , Su’ud Z. , Waris A. , Irwanto D.
Published: February 2021

The design study of GFR concepts comprises neutronic analysis of fuel pin and fuel assembly. The Monte Carlo method has advantages in three-dimensional (3D) geometry modeling but requires a high computation time. In this research, the comparative study of Gas-cooled Fast Reactor (GFR) using the Monte Carlo code. The GFR feasibility design study will be carried out with natural uranium with plutonium as fuel cycle inputs. The Monte Carlo method simulates GFR model at full-scale and heterogeneous three-dimensional (3D) using Evaluated Nuclear Data File (ENDF/B-VIII.b5) nuclear data. The code of Monte Carlo methods will be used in this research are the Monte Carlo N - Particle (MCNP) and OpenMC. The comparison of the GFR fuel assembly calculation simulation results is made between the MCNP and OpenMC code. The equilibrium cycle configuration is used as the basis model for the comparisons. The comparison of MCNP and OpenMC code gives a good agreement in criticality calculation of GFR that achieves delta kinf less than 1%. The (U-Pu)N fuel is a good candidate to be chosen in GFR research that gives kinf more than 1.1 in fissile contain 10%Pu and has the highest thermal conductivity. The Zircaloy-4 is the best candidate for material cladding in GFR design that provides the highest kinf.
Pebble Bed High Temperature Reactor for Electric and Cogeneration Application
Authors: Setiadipura T. , Irwanto D. , Suwoto  , Zuhair
Published: February 2021

Specific energy demand of Indonesia with its distributed energy demand required a special energy supply solution. The energy supply solution should be able to fulfil the electric demand of huge and growing population which spread in many different islands also to fulfil the energy demand to process abundances yet distributed natural sources. This paper proposes a pebble bed high temperature reactor as an energy supply in the form electric and/or cogeneration application. A parametric survey of the core geometry of a 150MWt Pebble Bed Reactor called PeLUIt is performed, follow by an equilibrium analysis of the optimized design. An accident analysis of depressurized loss of forced cooling (DLOFC) is performed to show the strong passive safety features of the design. Finally the heat-mass balance of the plant is also presented.
Heat transfer simulation in reactor cavity cooling system for experimental power reactor (RDE)
Authors: Yunus M , Kusumastuti R , Subekti M
Published: February 2021

To enhance the safety of experimental power reactor (RDE), Reactor Cavity Cooling System (RCCS) is required to support primary helium coolant. RCCS can be utilized for both normal condition or under accident. During the reactor accident with no power supplies and cooling pump down, RCCS works in a natural-circulation by using air in cavity and water in the cooling pipe. In this study, the process of radiation heat transfer from Reactor Pressure Vessel (RPV) to Water Cooled Pipe (WCP) was simulated. The natural circulation of air cavity and around the WCP was studied in three dimensional numerical model. The analyses are performed with Fluent code, which is a computational fluid dynamic code. Three parameter conditions of simulation were studied to compare the difference of them, so in this primary study, it can be known the influence of each parameter to the obtained results and it can be considered for development of future safety simulation in RDE reactor. From the simulation result, the temperature at bottom air cavity is higher than the top of the cavity. The temperature profile of water in the pipe also changes because of influence the heat transfer from Reactor Pressure Vessel. Gravity and radiation are very important parameter inputs to simulations in order to approach the real conditions.
Mechatronic Design HPS Test Loop of RDE
Authors: Kiswanta  , Sumarno E. , Santosa K. , Indrakoesoema K. , Handono K.
Published: February 2021

The electrical, mechanical and control system design of Helium Purification System Experimental Power Reactor Test Loop (RDE) has been conducted. The requirement system designed must be reliable operated, safety to personnel and equipments, ease of maintenance and operation, protection of equipment electrically, interchangeability of equipments and addition of the several model of tranducer. In order to achieve the above goals and obtain the desired results, the system based on electrical and instrumentation practical experiences will be needed. In this paper consist of the HPS electrical design and the instrumentation and control system. The criteria and the methods of designs of electrical and instrument equipments of the system have been discussed and investigated. The electrical and instrumentation control system drawing and requirement of design will be presented as the outcome of the design. The designed of power system analisys and also to overcome the problem of under voltage is consequently simulated by ETAP 12.6.
Mechanical properties and meso-damage evolution behavior of SUS 304 austenitic stainless steel
Authors: Liu Q , Li L , Shi Z M , Zhang H , Zhao H
Published: February 2021

Using MTS-Landmark material testing machine, Quanta-650 scanning electronic microscopy and Leica-LM/DM optical properties microscope, the mechanical properties and meso-damage evolution behavior of AISI304 steel at different annealing temperatures were studied. The results showed that the grain of AISI 304 steel grew up with increasing annealing temperature, and annealing twins appeared during the grain growth. The yield strength, tensile strength and micro-hardness of the samples decreased gradually with increasing annealing temperature. Based on the evolution characteristics of austenite grain boundaries, evolution of shape factor of the samples was researched at different plastic strains. Meso-damage evolution equations of the materials were established, and the material constant in the equation were closely related to the annealing temperatures. Normalized shape factor can reflect meso-damage evolution behavior of AISI 304 steel, which simply and effectively revealed the relation between marco deformation and microstructure.
Stepped Impedance 7th order Maximally Flat Low Pass Filter Using Microstrip Line for X-Band Applications
Authors: Salama S , Battah Y , Abuelhaija A
Published: February 2021

In this paper stepped impedance 7th order maximally flat low pass filter is designed and analyzed for X-band range at 9 GHz cut-off frequency. The filter is printed on Alumni substrate of dielectric constant 9.6 and thickness of 1.6 mm. The obtained attenuation is more than 20 dB. The Advanced Design System (ADS) software is used to design and simulate the proposed low pass filter. In addition, a comparison between filter design using insertion loss method implemented in stubs and stepped impedance is presented and discussed.
Dijkstra and Bidirectional Dijkstra on Determining Evacuation Routes
Authors: Rahayuda I G S , Santiari N P L
Published: February 2021

Determination of the best path or often called the shortest path finding is a method that has many benefits and can be applied in various cases and fields of science. In previous studies, authors have developed the shortest path finding program using various algorithms, such as held-karp, iterative deepening search, bidirectional depth first search and depth limited search. In this research author implements shortest path finding on information system for determining fire disaster evacuation route using Dijkstra and bidirectional Dijkstra. The program was developed based on web using vuetify.js framework. Both algorithms were tested on several datasets and the results will be compared to find out the strengths and weaknesses. Based on the research, the algorithm was successfully developed based on the web using the vuetify.js framework and successfully tested on several datasets, it is known that 40% of the test results show that bidirectional Dijkstra is better than Dijkstra, 10% vice versa and 50% get the same results from both algorithms. From this comparison it can be concluded that the bidirectional Dijkstra algorithm is better than Dijkstra. This research succeeded in proving that the bidirectional Dijkstra algorithm can produce a better route than the standard or classic Dijkstra algorithm.
Improving cold-region streamflow estimation by winter precipitation adjustment using passive microwave snow remote sensing datasets
Authors: Kang D , Lee K , Kim E J
Published: February 2021

Winter precipitation estimations and spatially sparse snow observations are key challenges when predicting snowmelt-driven floods. An improvement in streamflow prediction is achieved in a snowmelt-dominant basin, i.e. the Red River Basin (RRB), by adjusting the amounts of snowfall through satellite-borne passive microwave observations of snow water equivalent (SWE). A snowfall forcing dataset is scaled to minimize the difference between simulated and observed SWE over the RRB. Advanced microwave scanning radiometer-E (AMSR-E) SWE products serve as the observed SWE to obtain the solution to the linear equation between the AMSR-E and the baseline (no snowfall-forcing adjustment) SWE to yield a multiplication factor (M
factor). In the headwaters of the RRB in the United States, a Nash–Sutcliffe efficiency (NSE) of 0.74 is obtained against observed streamflow, with M
factor-adjusted streamflow during the snowmelt seasons (January to April). The baseline streamflow simulation without M
factor exhibits an NSE of 0.38 owing to an underestimated SWE.
Quantum state transmission through a spin chain in finite-temperature heat baths
Authors: Wang Zhao-Ming , Ren Feng-Hua , Luo Da-Wei , Yan Zhan-Yuan , Wu Lian-Ao
Published: February 2021

Transmission of a quantum state is essential for performing quantum information processing tasks. The communication channel will be inevitably immersed in its surrounding environment under realistic conditions. In this paper, we investigate the influence of environment noise on the transmission fidelity when transferring a quantum state through a spin chain. The non-Markovian open system dynamics is systematically analyzed by using the quantum state diffusion equation method. With each spin immersed in its own finite temperature and non-Markovian heat bath, we consider three types of system–bath interaction: dephasing, dissipation and spin-boson. The transmission fidelity is found to decrease with the increasing bath temperature and system–bath coupling strength. Interestingly, we find that the bath non-Markovianity can help enhancing the transmission fidelity.
The role of the non-linearity in controlling the surface roughness in the one-dimensional Kardar–Parisi–Zhang growth process
Authors: Priyanka  , Täuber Uwe C , Pleimling Michel
Published: February 2021

We explore linear control of the one-dimensional non-linear Kardar–Parisi–Zhang (KPZ) equation with the goal to understand the effects the control process has on the dynamics and on the stationary state of the resulting stochastic growth kinetics. In linear control, the intrinsic non-linearity of the system is maintained at all times. In our protocol, the control is applied to only a small number n
c of Fourier modes. The stationary-state roughness is obtained analytically in the small-n
c regime with weak non-linear coupling wherein the controlled growth process is found to result in Edwards–Wilkinson dynamics. Furthermore, when the non-linear KPZ coupling is strong, we discern a regime where the controlled dynamics shows scaling in accordance to the KPZ universality class. We perform a detailed numerical analysis to investigate the controlled dynamics subject to weak as well as strong non-linearity. A first-order perturbation theory calculation supports the simulation results in the weak non-linear regime. For strong non-linearity, we find a temporal crossover between KPZ and dispersive growth regimes, with the crossover time scaling with the number n
c of controlled Fourier modes. We observe that the height distribution is positively skewed, indicating that as a consequence of the linear control, the surface morphology displays fewer and smaller hills than in the uncontrolled growth process, and that the inherent size-dependent stationary-state roughness provides an upper limit for the roughness of the controlled system.
Low-density limit of dynamical correlations in the Lieb–Liniger model
Authors: Granet Etienne
Published: February 2021

We derive explicit expressions for dynamical correlations of the field and density operators in the Lieb–Liniger model, within an arbitrary eigenstate with a small particle density

D

. They are valid for all space and time and any interaction strength
c
> 0, and are the leading order of an expansion in

D

. This expansion is obtained by writing the correlation functions as sums over form factors when formally decomposed into partial fractions.
Some results of ecological breeding of yellow lupine
Authors: Dragunskaya M G , Savicheva I K , Yu Leshchenko P , Adamkov V N
Published: February 2021

The studied and generalized data indicate the ambiguity of the reaction of varieties of yellow Lupinus (Lupinus Luteus L), created in various research institutes in the country and abroad, to the ecological and geographical conditions of the regional zone. The strain VNII of lupine Reliable formed grain yield of 1.16 t/ha, at the level of varieties of breeding Novozybkov agricultural experimental station (NAS) Friendly 165 – 1.17 and Novozybkosky 100 – 1,22 t/ha,and varieties Brigantine and Bulat on grain yield was, respectively, 0.09 to 0.24 t/ha and 0.14-0.29 t/ha. Kastrychnik and Vladko (Belarusian selection) decreased productivity relative to Druzhny 165 by 0.25-0.45 t / ha and Novozybkosky 100 by 0.30-0.50 t / ha. Varieties of foreign selection Mister and Lord undergo a period of adaptation to the soil and climatic conditions of the regional zone, so the grain yield is lower than Amicable 165 by 0.29-0.49 t / ha and Novozybkosky 100 by 0.34-0.54 t / ha. In the hybrid material of the 2008-2014 NSOS of the crossing years, samples 1-08-7-75, 5-10-84, 2-13-33 and 7-13-65 were distinguished by grain yield of 1.32-1.34 t/ha, while the remaining numbers were at the level of the best varieties by productivity. Anthracnose infestation in 2018 and 2019 of green mass and beans was low due to arid vegetation conditions. In 2020, climatic conditions contributed to the development of Anthracnose in the phase of the blue-brilliant bean, dividing the studied varieties into highly resistant ones: Friendly 165, Novozybkosky 100, Reliable, Mister and Lord and stable: Brigantine, Bulat, Kastrychnik and Vladko. Hybrid samples were affected by 15.7-19.7%, with the exception of the number 5-10-84-34.1% and are highly resistant and stable. Under conditions of radioactive contamination of the soil, the concentration of caesium-137 in the grain of Druzhny 165, Novozybkosky 100 and Reliable varieties was at the level of 300-393 Bq/kg, which is 1.5-2.0 times higher than the standard for feed grain of 200 Bq/kg. Castrychnik exceeded the norm by 1.7-2.4 times, and Mister and Lord accumulated a radioisotope within the norm in 2018 and above it by 1.8-2.3 times in 2019. Samples of hybrid material (data for 2018) contained
137Cs in grain at the standard level: with fluctuations from 112 to 265 Bq/kg. Thus, to solve the problem of providing livestock with high-protein feed, preserving the soil fertility of sandy soils, it is very important to develop ecological breeding that makes maximum use of the agro and bioclimatic resources of the zone.
Printability in extrusion bioprinting
Authors: Fu Zhouquan , Naghieh Saman , Xu Cancan , Wang Chengjin , Sun Wei , Chen Xiongbiao
Published: February 2021

Extrusion bioprinting has been widely used to extrude continuous filaments of bioink (or the mixture of biomaterial and living cells), layer-by-layer, to build three-dimensional constructs for biomedical applications. In extrusion bioprinting, printability is an important parameter used to measure the difference between the designed construct and the one actually printed. This difference could be caused by the extrudability of printed bioink and/or the structural formability and stability of printed constructs. Although studies have reported in characterizing printability based on the bioink properties and printing process, the concept of printability is often confusingly and, sometimes, conflictingly used in the literature. The objective of this perspective is to define the printability for extrusion bioprinting in terms of extrudability, filament fidelity, and structural integrity, as well as to review the effect of bioink properties, bioprinting process, and construct design on the printability. Challenges related to the printability of extrusion bioprinting are also discussed, along with recommendations for improvements.
Superposition of intra- and inter-layer excitons in twistronic MoSe2/WSe2 bilayers probed by resonant Raman scattering
Authors: McDonnell Liam P , Viner Jacob J S , Ruiz-Tijerina David A , Rivera Pasqual , Xu Xiaodong , Fal’ko Vladimir I , Smith David C
Published: February 2021

Hybridisation of electronic bands of two-dimensional materials, assembled into twistronic heterostructures, enables one to tune their optoelectronic properties by selecting conditions for resonant interlayer hybridisation. Resonant interlayer hybridisation qualitatively modifies the excitons in such heterostructures, transforming these optically active modes into superposition states of interlayer and intralayer excitons. For MoSe2/WSe2 heterostructures, strong hybridization of both single particle and excitonic states can occur via single particle tunnelling. Here we use resonance Raman scattering to provide direct evidence for the hybridisation of excitons in twistronic MoSe2/WSe2 structures, by observing scattering of specific excitons by phonons in both WSe2 and MoSe2. We also demonstrate that resonance Raman scattering spectroscopy opens up a wide range of possibilities for quantifying the layer composition of the superposition states of the exciton and the interlayer hybridisation parameters in heterostructures of two-dimensional materials.
Direct synthesis of hierarchical porous polymer nanoparticles from nitrile monomers and its application for methylene blue adsorption
Authors: Shi En , Wang Xinyu , Zhang Miao , Fang Yanfeng , Gao Jianchun , Wang Xin , Zheng Yunbin
Published: February 2021

Microporous covalent triazine-based frameworks (CTFs) have been widely used as adsorbents, separation and catalysts in the past few years, but the confined microporous network often induces diffusion limitations of molecules to and from the active sites. Here, we present a general bottom-up synthetic strategy to produce hierarchical porous polymer nanoparticles by cyclotrimerization of 1,4-dicyanobenzene in molten ZnCl2. Controlling the ratio of monomer to molten salts is the key to prepare hierarchical porous polymer nanoparticles by ionothermal methods, and uniform nanoparticles with particle size of 100–400 nm can be facilely synthesized at a low monomer/ZnCl2 molar ratios. The resulting hierarchical porous polymer nanoparticles exhibit great adsorption capacity of methylene blue. The enhancement is ascribed to enhanced mass transfer of the molecules and easy access to the active sites as a result of the short diffusion lengths of hierarchical porous polymer nanoparticles. This method is simple and efficient for the preparation of size-controllable hierarchical porous polymer nanoparticles from nitrile monomers, which is conducive to expand its application in adsorption, catalysis and other related fields.
Insights into the reinforcement and mechanism of silicone mold rubber co-modified with WCB and MMQ resin
Authors: Hao Wenli , Zeng Hehua , Chen Xiqing , He Wei , Zhou Rui , Li Jianhui , Zhang Hongxi
Published: February 2021

The exploitation of condensation room-temperature vulcanized silicone rubber (C-RTV) with excellent mechanical properties and thermal stability is of great practical significance in the preparation of insulation materials and rubber products with high performance. In this work, novel silicone rubber was fabricated successfully by adding white carbon black (WCB) and different percentages of methyl MQ (MMQ) silicone resin to C-RTV silicone mold rubbers (C-RTV/WMMQ). The mechanical properties, dimensional thermal stabilities, and thermal decomposing temperatures of the as-prepared samples were investigated in detail. Compared to the primitive C-RTV, the tensile strength of the sample with the WCB adding an amount of 15% increased from 0.44 MPa to 3.9 MPa. When the 1% MMQ was introduced, the tensile strength further increased to 4.4 MPa, suggesting a 12.8% reinforcement rate in addition to the improvements in the dimensional thermal stabilities and decomposing temperature. Based on the experimental results, a feasible synergistic effect and compatibility mechanism was proposed that hydrogen bond formed on the interface between MMQ resin and C-RTV in addition to the rigid structure of WCB, and thus led to a dense crosslinking network structure in the polymer matrix.
The spatial and energy distribution of oxide trap responsible for 1/f noise in 4H-SiC MOSFETs
Authors: Chen Hua , He Liang
Published: February 2021

Low-frequency noise is one of the important characteristics of 4H-SiC metal-oxide-semiconductor field-effect transistors (MOSFETs) that is susceptible to oxide traps. Drain-source voltage noise models of 4H-SiC MOSFETs under low–drain-voltage and inverse condition were proposed by considering the spatial and energy non-uniform distribution of the oxide trap, based on the McWhoter model for uniform trap distribution. This study performed noise experiments on commercial 4H-SiC MOSFETs, and revealed that the non-uniform spatial and non-uniform energy distribution caused new 1/f noise phenomenon, different from that under uniform spatial and energy distribution. By combining experimental data and theoretical models, the spatial and energy distribution of oxide traps of these samples were determined.
Polarization-resolved supercontinuum generated in a germania-doped photonic crystal fiber
Authors: Couture Nicolas , Ostic Rachel , Reddy P Harshavardhan , Kar Ajoy Kumar , Paul Mukul Chandra , Ménard Jean-Michel
Published: February 2021

We characterize the polarization properties of a supercontinuum (SC) generated in a GeO2-doped photonic crystal fiber (PCF) to reveal the interplay between nonlinear broadening mechanisms of a pulse propagating in two independent fundamental modes associated to the principal axes of the fiber. Notably, we resolve self-phase modulation, self-shifted Raman solitons and dispersive waves within a set of orthogonal polarization states as they contribute to generate a broad spectrum spanning from 450 to 2150 nm. Interestingly, our experimental results feature a high degree of polarization at the edges of the spectrum in comparison to the region near the pump wavelength. We show that this modulation is caused by nonlinear spectral broadening. We also identify an additional depolarization mechanism preferentially acting on shorter wavelengths, indicative of a Rayleigh-like scattering effect due to the presence of intrinsic sub-wavelength defects in the fiber. Experiments rely on a free-space grating-based monochromator and a broadband polarizer to monitor the output SC and its linear polarization components along the principal axes of the PCF. Our results and experimental technique pave the way toward an improved standard for the characterization of broadband optical spectra and more efficient implementation of highly nonlinear fibers in a large range of polarization-sensitive applications.
Studies and optimization of hybrid X-pinches
Authors: Elshafiey A T , Musk J H , Pikuz S A , Shelkovenko T A , Hammer D A
Published: February 2021

Studies were carried out on the hybrid X-pinch (HXP) configuration for several wire materials using a 40 ns risetime, 300-kA pulsed-power generator with the goal of optimizing the HXP x-ray burst parameters for different applications. The gap distance between the conical electrodes of the hybrid X-pinch was varied from 0.5 to 5 mm for Al, Ag, Ti, and Mo using different wire diameters to maintain a consistent mass per unit length from one material to the next. It was found that 0.5–1 mm gap spacing was optimal to obtain a single x-ray burst, while the number of x-ray bursts increased with gap spacing for all materials at a rate of 1–2/mm. Time consistency studies of the first x-ray burst were carried out for Ti wire by changing the gap distance and wire diameter while observing the time of occurrence of the x-ray bursts. It was found that a 40 μm Ti wire load with a 3 mm electrode gap spacing had the highest probability to have the first x-ray burst reproducibly within a 2 ns time window. Time-resolved and time-integrated diagnostics provided information about the source size, time of occurrence, intensity, and the number of the x-ray bursts.
A perfect 2D auxetic sliding mechanism based on an Islamic geometric pattern
Authors: Lim Teik-Cheng
Published: February 2021

A new auxetic microstructure is introduced herein by inspiration from an Islamic geometric pattern that consists of square array of 8-pointed rigid stars interspersed with square array of 4-pointed rigid stars. By permitting each star to slide across its adjoining neighbors through incorporation of slots and sliders in the stars, an in-plane isotropic Poisson’s ratio of −1, and hence equi-biaxial strain, is achieved upon applied uniaxial compression. Apart from the negativity of Poisson’s ratio, another counter-intuitive property is the occurrence of global rotation of the entire structure relative to the stars during compression. Results indicate that when fully compressed, the in-plane strain is −0.232 with the accompanying global rotation of 6.18 degrees. Without the 4-pointed stars, the system can achieve an in-plane strain of −0.288 with a corresponding global rotation of 7.86 degrees.
Model improvement and SOC estimation based on aluminium ion batteries
Authors: Jia Wang , Sun Xiujuan , Lin Mengchang , Wang Chuanjiang , Du Huiping , Chen Pijian , Liu Zhidong
Published: February 2021

The main work of this paper can be divided into three parts: (1) An aluminium ion battery is made, the battery capacity is calibrated under a constant current, and the battery’s voltage and current data under pulse conditions is collected. (2) The influence of the hysteresis effect on the SOC estimation of aluminium ion batteries is fully considered. A model suitable for aluminium ion batteries is established based on the model that the parameter identification and verification was carried out with. (3) The error with the EKF and AEKF algorithms in estimating the SOC of aluminium ion batteries is compared. The experimental results show that the model established in this paper can describe the working state of aluminium ion batteries very well. Compared with the EKF algorithm, the AEKF algorithm is more accurate in estimating the SOC of aluminium ion batteries.
Effects of (Ti,W)C on the properties of Stellite12 overlays
Authors: Zhang Guodong , Qiao Xiyue , Zhou Yicheng
Published: February 2021

The Stellite12 overlay and (Ti,W)C-reinforced overlay have been successfully manufactured on the Q235 steel by plasma arc powder surfacing and effects of (Ti,W)C on the properties of Stellite12 overlay have been studied. Microstructure has been investigated using optical microscope(OM), scanning electron microscope(SEM) with energy dispersive spectroscopy(EDS). Results show that the addition of (Ti,W)C changes the Stellite12 overlay characterized by the Co-rich solid solution and eutectic structure to the (Ti,W)C-reinforced overlay characterized by the dispersed (Ti,W)C particles, fishbone dendrites and blocky dendrites. Microhardness and macrohardness have been evaluated using Vickers hardness tester and Rockwell hardness tester. Results show that macrohardness has been improved when (Ti,W)C is added into the Stellite12 overlay. In addition, the results of electrochemical testing show that the corrosion resistance of the (Ti,W)C-reinforced overlay is better than the Stellite12 overlay.
Towards automated analysis for neutron reflectivity
Authors: Mironov Daniil , Durant James H , Mackenzie Rebecca , Cooper Joshaniel F K
Published: February 2021

We describe a neural network-based tool for the automatic estimation of thin film thicknesses and scattering length densities from neutron reflectivity curves. The neural network sits within a data pipeline, that takes raw data from a neutron reflectometer, and outputs data and parameter estimates into a fitting program for end user analysis. Our tool deals with simple cases, predicting the number of layers and layer parameters up to three layers on a bulk substrate. This provides good accuracy in parameter estimation, while covering a large portion of the use case. By automating steps in data analysis that only require semi-expert knowledge, we lower the barrier to on-experiment data analysis, allowing better utility to be made from large scale facility experiments. Transfer learning showed that our tool works for x-ray reflectivity, and all code is freely available on GitHub (neutron-net 2020, available at: https://github.com/xmironov/neutron-net) (Accessed: 25 June 2020).
Cranial integration in the ring-necked parakeet, Psittacula krameri (Psittaciformes: Psittaculidae)
Authors: Mitchell Matthew J , Goswami Anjali , Felice Ryan N
Published: February 2021

The study of integration and modularity aims to describe the organization of components that make up organisms, and the evolutionary, developmental and functional relationships among them. Both have been studied at the interspecific (evolutionary) and intraspecific (phenotypic and ontogenetic) levels to different degrees across various clades. Although evolutionary modularity and integration are well-characterized across birds, knowledge of intraspecific patterns is lacking. Here, we use a high-density, three-dimensional geometric morphometric approach to investigate patterns of integration and modularity in Psittacula krameri, a highly successful invasive parrot species that exhibits the derived vertical palate and cranio-facial hinge of the Psittaciformes. Showing a pattern of nine distinct cranial modules, our results support findings from recent research that uses similar methods to investigate interspecific integration in birds. Allometry is not a significant influence on cranial shape variation within this species; however, within-module integration is significantly negatively correlated with disparity, with high variation concentrated in the weakly integrated rostrum, palate and vault modules. As previous studies have demonstrated differences in beak shape between invasive and native populations, variation in the weakly integrated palate and rostrum may have facilitated evolutionary change in these parts of the skull, contributing to the ring-necked parakeet’s success as an invasive species.
Hybrid effects in field populations of the African monarch butterfly, Danaus chrysippus (L.) (Lepidoptera: Nymphalidae)
Authors: Smith David As , Bennie Jon J , Gordon Ian J , Martin Simon , Ireri Piera , Omufwoko Kennedy S , Ffrench-Constant Richard H
Published: February 2021

Heterosis, Haldane and Bateson-Dobzhansky-Muller effects have been widely documented amongst a range of plants and animals. However, typically these effects are shown by taking parents of known genotype into the laboratory and measuring components of the F1 progeny under laboratory conditions. This leaves in doubt the real significance of such effects in the field. Here we use the well-known colour pattern genotypes of the African monarch or queen (Danaus chrysippus), which also control wing length, to test these effects both in the laboratory and in a contact zone in the field. By measuring the wing lengths in animals of known colour pattern genotype we show clear evidence for all three hybrid effects at the A and BC colour patterning loci, and importantly, that these same effects persist in the same presumptive F1s when measured in hybrid populations in the field. This demonstrates the power of a system in which genotypes can be directly inferred in the field and highlights that all three hybrid effects can be seen in the East African contact zone of this fascinating butterfly.
Contour prognostic model for predicting survival after resection of colorectal liver metastases: development and multicentre validation study using largest diameter and number of metastases with RAS mutation status
Authors: Kawaguchi Y , Kopetz S , Tran Cao H S , Panettieri E , De Bellis M , Nishioka Y , Hwang H , Wang X , Tzeng C -W D , Chun Y S , Aloia T A , Hasegawa K , Guglielmi A , Giuliante F , Vauthey J -N
Published: February 2021

Background

Most current models for predicting survival after resection of colorectal liver metastasis include largest diameter and number of colorectal liver metastases as dichotomous variables, resulting in underestimation of the extent of risk variation and substantial loss of statistical power. The aim of this study was to develop and validate a new prognostic model for patients undergoing liver resection including largest diameter and number of colorectal liver metastases as continuous variables.

Methods

A prognostic model was developed using data from patients who underwent liver resection for colorectal liver metastases at MD Anderson Cancer Center and had RAS mutational data. A Cox proportional hazards model analysis was used to develop a model based on largest colorectal liver metastasis diameter and number of metastases as continuous variables. The model results were shown using contour plots, and validated externally in an international multi-institutional cohort.

Results

A total of 810 patients met the inclusion criteria. Largest colorectal liver metastasis diameter (hazard ratio (HR) 1.11, 95 per cent confidence interval 1.06 to 1.16; P < 0.001), number of colorectal liver metastases (HR 1.06, 1.03 to 1.09; P < 0.001), and RAS mutation status (HR 1.76, 1.42 to 2.18; P < 0.001) were significantly associated with overall survival, together with age, primary lymph node metastasis, and prehepatectomy chemotherapy. The model performed well in the external validation cohort, with predicted overall survival values almost lying within 10 per cent of observed values. Wild-type RAS was associated with better overall survival than RAS mutation even when liver resection was performed for larger and/or multiple colorectal liver metastases.

Conclusion

The contour prognostic model, based on diameter and number of lesions considered as continuous variables along with RAS mutation, predicts overall survival after resection of colorectal liver metastasis.
Classification of the colonic splenic flexure based on three-dimensional CT analysis
Authors: Kawai K , Nozawa H , Hata K , Tanaka T , Nishikawa T , Sasaki K , Ishihara S
Published: February 2021

Background

Mobilization of the splenic flexure can be a challenging surgical step in colorectal surgery. This study aimed to classify the splenic flexure based on the three-dimensional (3D) coordinates of the splenic hilum and left renal hilum. This classification was used to compare splenic flexure mobilization during colorectal resection.

Methods

CT images of patients with colorectal cancer treated between April 2018 and December 2019 were analysed retrospectively. 3D mutual positioning of the splenic flexure from the ligament of Treitz to the splenic hilum or the left renal hilum was used to classify patients into three groups using cluster analysis. The difference in the procedure time between groups was also analysed in a subset of patients undergoing laparoscopic colectomy with complete splenic flexure mobilization.

Results

Of 515 patients reviewed, 319 with colorectal cancers were included in the study and categorized based on the 3D coordinates of the splenic hilum and left renal hilum as caudal (100 patients), cranial (118) and lateral (101) positions. Male sex (P < 0.001), older age (P = 0.004) and increased bodyweight (P = 0.043) were independent characteristics of the lateral group in multiple logistic regression analysis. Thirty-four patients underwent complete splenic flexure mobilization during the study period; this took significantly longer (mean 78.7 min) in the lateral group than in the caudal and cranial groups (41.8 and 43.2 min respectively; P = 0.006).

Conclusion

Locating the splenic flexure using 3D coordinates could be helpful in predicting a longer duration for mobilization of the splenic flexure.
Utility of remnant liver volume for predicting posthepatectomy liver failure after hepatectomy with extrahepatic bile duct resection
Authors: Yamamoto R , Sugiura T , Okamura Y , Ito T , Yamamoto Y , Ashida R , Ohgi K , Otsuka S , Uesaka K
Published: February 2021

Background

Hepatectomy with extrahepatic bile duct resection is associated with a high risk of posthepatectomy liver failure (PHLF). However, the utility of the remnant liver volume (RLV) in cholangiocarcinoma has not been studied intensively.

Methods

Patients who underwent major hepatectomy with extrahepatic bile duct resection between 2002 and 2018 were reviewed. The RLV was divided by body surface area (BSA) to normalize individual physical differences. Risk factors for clinically relevant PHLF were evaluated with special reference to the RLV/BSA.

Results

A total of 289 patients were included. The optimal cut-off value for RLV/BSA was determined to be 300 ml/m2. Thirty-two patients (11.1 per cent) developed PHLF. PHLF was more frequent in patients with an RLV/BSA below 300 ml/m2 than in those with a value of 300 ml/m2 or greater: 19 of 87 (22 per cent) versus 13 of 202 (6.4 per cent) (P < 0.001). In multivariable analysis, RLV/BSA below 300 ml/m2 (P = 0.013), future liver remnant plasma clearance rate of indocyanine green less than 0.075 (P = 0.031), and serum albumin level below 3.5 g/dl (P = 0.015) were identified as independent risk factors for PHLF. Based on these risk factors, patients were classified into three subgroups with low (no factors), moderate (1–2 factors), and high (3 factors) risk of PHLF, with PHLF rates of 1.8, 14.8 and 63 per cent respectively (P < 0.001).

Conclusion

An RLV/BSA of 300 ml/m2 is a simple predictor of PHLF in patients undergoing hepatectomy with extrahepatic bile duct resection.
Postoperative non-steroidal anti-inflammatory drug use and oncological outcomes of rectal cancer
Authors: Grahn O , Lundin M , Lydrup M-L , Angenete E , Rutegård M
Published: February 2021

Background

Non-steroidal anti-inflammatory drugs (NSAIDs) are known to suppress the inflammatory response after surgery and are often used for pain control. This study aimed to investigate NSAID use after radical surgical resection for rectal cancer and long-term oncological outcomes.

Methods

A cohort of patients who underwent anterior resection for rectal cancer between 2007 and 2013 in 15 hospitals in Sweden was investigated retrospectively. Data were obtained from the Swedish Colorectal Cancer Registry and medical records; follow-up was undertaken until July 2019. Patients who received NSAID treatment for at least 2 days after surgery were compared with controls who did not, and the primary outcome was recurrence-free survival. Cox regression modelling with confounder adjustment, propensity score matching, and an instrumental variables approach were used; missing data were handled by multiple imputation.

Results

The cohort included 1341 patients, 362 (27.0 per cent) of whom received NSAIDs after operation. In analyses using conventional regression and propensity score matching, there was no significant association between postoperative NSAID use and recurrence-free survival (adjusted hazard ratio (HR) 1.02, 0.79 to 1.33). The instrumental variables approach, including individual hospital as the instrumental variable and clinicopathological variables as co-variables, suggested a potential improvement in the NSAID group (HR 0.61, 0.38 to 0.99).

Conclusion

Conventional modelling did not demonstrate an association between postoperative NSAID use and recurrence-free survival in patients with rectal cancer, although an instrumental variables approach suggested a potential benefit.
Increased Risk of High-grade Cervical Neoplasia in Women with Inflammatory Bowel Disease: A Case-controlled Cohort Study
Authors: Goetgebuer R L , Kreijne J E , Aitken C A , Dijkstra G , Hoentjen F , de Boer N K , Oldenburg B , van der Meulen A E , Ponsioen C I J , Pierik M J , van Kemenade F J , de Kok I M C M , Siebers A G , Manniën J , van der Woude C J , de Vries A C
Published: February 2021

Background and Aims

Women with inflammatory bowel disease [IBD] may be at higher risk for cervical intraepithelial neoplasia [CIN]. However, data are conflicting. The aim of this study was to assess the risk of high-grade dysplasia and cancer [CIN2+] in IBD women and identify risk factors.

Methods

Clinical data from adult IBD women in a multicentre Dutch IBD prospective cohort [PSI] from 2007 onwards were linked to cervical cytology and histology records from the Dutch nationwide cytology and pathology database [PALGA], from 2000 to 2016. Patients were frequency-matched 1:4 to a general population cohort. Standardised detection rates [SDR] were calculated for CIN2+. Longitudinal data were assessed to calculate CIN2+ risk during follow-up using incidence rate ratios [IRR] and risk factors were identified in multivariable analysis.

Results

Cervical records were available from 2098 IBD women [77%] and 8379 in the matched cohort; median follow-up was 13 years. CIN2+ detection rate was higher in the IBD cohort than in the matched cohort (SDR 1.27, 95% confidence interval [CI] 1.05–1.52). Women with IBD had an increased risk of CIN2+ [IRR 1.66, 95% CI 1.21–2.25] and persistent or recurrent CIN during follow-up (odds ratio [OR] 1.89, 95% CI 1.06–3.38). Risk factors for CIN2+ in IBD women were smoking and disease location (ileocolonic [L3] or upper gastrointestinal [GI] [L4]). CIN2+ risk was not associated with exposure to immunosuppressants.

Conclusions

Women with IBD are at increased risk for CIN2+ lesions. These results underline the importance of human papillomavirus [HPV] vaccination and adherence to cervical cancer screening guidelines in IBD women, regardless of exposure to immunosuppressants.