bluuebunny/crossref_metadata_2025 huggingface dataset:
Hazard Identification on the Process of High-Level Liquid Waste Concentration and Denitration in Spent Fuel Reprocessing by HAZOP
Authors: Wang Weishuai , Liu Xuegang , He Qian-ge , Wang Xinghai
Published: April 2023

To develop China’s spent nuclear fuel reprocessing, safety analysis of reprocessing facility is of great importance and high priority. Any methodology of safety analysis, no matter whether it is in a kind of deterministic analysis, probabilistic assessment or so-called Integrated Safety Analysis, is beginning with the identification and systematic analysis of hazards as the very first essential step. Recognizing that reprocessing facilities are, to a large extent, chemical processing plants, HAZard and OPerability analysis (HAZOP) was introduced firstly in the US. It is featured as one of the most suitable methods for performing detailed identification of a wide range of hazards.

In this paper, our work on part of the concentration and denitration process (C/D process) of high-level liquid waste (HLLW) was revealed to exemplify the procedure of hazard identification and analysis for a typical reprocessing process, as the C/D process of HLLW has many symbolic features of spent fuel reprocessing, such as high radiation, various chemicals, complex chemical reactions and operation stages. The purpose of this paper was to test the applicability of HAZOP for a typical process in reprocessing.

The HAZOP approach was starting with the identifications of process, reactions, equipment, and system borders. Base on the features of the given system (part), specific elements and guidewords were selected and combined to generate deviations for different operation stages. The possible causes and consequences of deviation as well as existing safeguards were taken into consideration. To make the workflow of HAZOP complete and underscore its significance, a 4-by-5 risk matrix was established to evaluate the risk levels of all consequences resulted from deviations, based on the severity of consequence and associated likelihood of occurrence.

The final results were shown in a HAZOP analysis worksheet, in which twenty-two deviations were presented, revealing the potential hazards found in the C/D part. After a preliminary risk assessment using a risk matrix, eight of them were recognized as undesirable risks (only accepted when risk reduction is impracticable). The results verified that the HAZOP analysis was suitable for the processes or parts involved with high radiation and complex chemical reactions in reprocessing facilities.
Development of Subchannel Code for Plate-Type Fuel Plus Verification
Authors: Zhang Bo , Jiang Gefan , Zhai Peichao , Shan JianQiang
Published: April 2023

The fuel shape and flow path structure of the plate-type fuel reactor are different from those of the conventional rod-bundle reactor, which leads to the difference between the thermal-hydraulic phenomenon and thermal conduction in the rod bundle assembly. Therefore, in this thesis, the subchannel analysis model and code applied to the plate-type fuel reactor are developed. The calculation results of the code are compared with the simulation results of FLUENT and MATRA and the experimental results of the flow and heat transfer of the rectangular channel, so that the code is verified.

This thesis first fully investigated the thermal-hydraulic and friction models applicable to rectangular flow channels, and developed the plate-type fuel heat conduction model and flow redistribution model. On the basis of the existing two-fluid three-field subchannel code, the subchannel analysis software for the plate type fuel reactor was developed. The comparison with the rectangular channel heat transfer experiment shows that the code can accurately predict the heat transfer coefficient under the rectangular channel. The comparison and verification with the simulation calculation results of the MTR reactor under steady-state conditions with the FLUENT and MATRA codes show that the developed subchannel code can simulate the thermal-hydraulic phenomena of the plate fuel assembly. Finally, according to the calculation results of the MTR reactor by the code, the thermal-hydraulic characteristics of the plate fuel reactor are analyzed, and the safety of the plate fuel is evaluated.
A Moose-Based Neutron Diffusion Code with Application to a LMFR Benchmark
Authors: Wang Weixiang , Feng WenPei , Zhang KeFan , Yang Guangliang , Ding Tao , Chen Hongli
Published: April 2023

MOOSE (Multiphysics Object-Oriented Simulation Environment) is a powerful finite element multi-physics coupling framework, whose object-oriented, extensive system is conducive to the development of various simulation tools. In this work, a full-core MOOSE-based Neutron Diffusion application is developed, and a 3D PWR benchmark 3D-IAEA with given group constants is applied for code verification. Then the MOOSE-based Neutron Diffusion application is applied to the calculation of a Sodium-cooled Fast Reactor (SFR) benchmark, together with the research on homogenized few-group constants generation based on Monte Carlo method. The calculation adopts a 33-group cross section sets, which is generated using Monte Carlo code OpenMC. Considering the long neutron free path and strong global neutron spectrum coupling of liquid metal cooled reactor (LMFR), a full-core homogeneous model is used in OpenMC to generate the homogenized few-group constants. In addition, transport correction is used in the process of cross section generation, considering the prominent anisotropic scattering of fast reactor. The calculated results, including effective multiplication factor (keff) and assembly power distributions, are in good agreement with the reference values and the calculation results of OpenMC, which proves the accuracy of the neutron diffusion application, and also shows that the Monte Carlo method can be applied to generation of homogenized few-group constants for LMFR analysis.
Research on High-Performance Concrete for Volute Region of PX Combined Pump Room in Hualong Nuclear Power Plant
Authors: Liu Xiangkun , Zhou Chongxu , Hu Dehua , Zhang Wei
Published: April 2023

Aiming at the volute area concrete structure design requirements for PX combined pump room of HUALONG, the high performance concrete with wonderful property resistance to harmful ion erosion was made by optimization design. The strength grade of the concrete is CF50. Based on experimental result, its slump was 195 mm, its compressive strength was 60.9 MPa with the chloride ion permeability coefficient was 3.6 × 10−12 m2/s at twenty-eight days, and the restrained expansion rate was 2.7 × 10–4 with the dry shrinkage rate was 1.3 × 10–4. All the technical indexes conform to the design and construction requirements. Verified by engineering application, concrete compressive strength during continuous production period was according to the evaluation criteria of GB/T 50107-2010. And the standard deviations were only 1.64 MPa. It indicates that the concrete quality is stable and controlled.
Dynamic Response Analysis of Floating Nuclear Power Plant Containment Under Marine Environment
Authors: Cui Jialin , Li Lijuan , Zhang Meng , Liu Hongbing , Qu Xianqiang
Published: April 2023

Floating nuclear containment is in a harsher environment than conventional onshore nuclear containment. In view of the Marine environment under the condition of floating nuclear power plant containment structure safety, combined water dynamics and structural mechanics, considering the containment response under random movement of hull in the Marine environment, the influence of the containment structure load calculation, thus checking containment when working in pile structure safety, provide theoretical basis for the safe operation of floating nuclear power plants. In this paper, taking a floating nuclear power plant as an example, ANSYS 2021R1, Workbench, Fluent and other software of finite element analysis are used to conduct fatigue simulation of floating nuclear power plant. The time course curve of the 6-dof motion of the ship’s center of gravity is obtained, then, a remote displacement method is adopted to transfer the hull motion to the containment vessel to realize the numerical simulation of the containment vessel movement with the hull, thus to solve maximum normal stress and strain, the maximum load component of containment bearing under the action of Marine environmental load is obtained. The results show that the maximum stress and strain of the vessel increase obviously in the moving state compared with the static state of the vessel, which indicates that the random motion response of the vessel must be considered in the structural safety analysis of the floating nuclear power plant containment.
Research on Process Diagnosis of Severe Accidents Based on Deep Learning and Probabilistic Safety Analysis
Authors: Liu Zheng , Wang Hao
Published: April 2023

Severe accident process diagnosis provides data basis for severe accident prognosis, positive and negative effect evaluation of Severe Accident Management Guidelines (SAMGs), especially to quickly diagnose Plant Damage State (PDS) for operators in the main control room or personnel in the Technical Support Center (TSC) based on historic data of the limited number of instruments during the operation transition from Emergency Operation Procedures (EOPs) to SAMGs. This diagnosis methodology is based on tens of thousands of simulations of severe accidents using the integrated analysis program MAAP. The simulation process is organized in reference to Level 1 Probabilistic Safety Analysis (L1 PSA) and EOPs. According to L1 PSA, the initial event of accidents and scenarios from the initial event to core damage are presented in Event Trees (ET), which include operator actions following up EOPs. During simulation, the time uncertainty of operations in scenarios is considered. Besides the big data collection of simulations, a deep learning algorithm, Convolutional Neural Network (CNN), has been used in this severe accident diagnosis methodology, to diagnose the type of severe accident initiation event, the breach size, breach location, and occurrence time of the initial event of LOCA, and action time by operators following up EOPs intending to take Nuclear Power Plant (NPP) back to safety state. These algorithms train classification and regression models with ET-based numerical simulations, such as the classification model of sequence number, break location, and regression model of the break size and occurrence time of initial event MBLOCA. Then these trained models take advantage of historic data from instruments in NPP to generate a diagnosis conclusion, which is automatically written into an input deck file of MAAP. This input deck originated from previous traceback efforts and provides a numerical analysis basis for predicting the follow-up process of a severe accident, which is conducive to severe accident management. Results of this paper show a theoretical possibility that under limited available instruments, this traceback and diagnosis method can automatically and quickly diagnose PDS when operation transit from EOPs to SAMGs and provide numerical analysis basis for severe accident process prognosis.
Preparation and Properties of Graphite Surface Vitrification Y2O3 Coating
Authors: Lei Zhen , Li Hongya , Yu Bingzhai , Geng Binghan
Published: April 2023

The Mo-Y2O3 composite coating was prefabricated on the surface of the graphite crucible by plasma spraying, and then the coating surface was remelted by high-power laser. The coating was subjected to SEM analysis, X-ray diffraction, bond strength testing, and molten terbium metal corrosion test. The results show, After laser cladding treatment, the problems of pores and unmelted particles on the surface of the Mo-Y2O3 coating have been significantly improved, and the porosity has been reduced to less than 1.5%, Vitrified Y2O3 with a thickness of about 80–120 μm and columnar crystal growth was formed on the surface of the coating, and the bonding strength was increased from 2–3 MPa before treatment to 7–11 MPa, In the corrosion assessment test of molten terbium metal, the coating was intact and did not fall off, the surface of the ingot was not adhered, and there was no contamination by impurity elements, which could be easily demolded.
Numerical Study on the Mechanism of Oxygen Diffusion During Oxygen Control Process in Heavy Liquid Metals
Authors: Li Ying , Guo Liang , Zhang Chao , You Hongbo , Zan Yuanfeng
Published: April 2023

In order to investigate the mechanisms and characteristics of oxygen diffusion during oxygen control in Heavy Liquid Metals (HLM). Turbulence model coupling species transport model are used to predict the oxygen transport and distribution in liquid lead-bismuth eutectic (LBE) during gas oxygen control process. The oxygen mass flow coefficients are calculated under diffident LBE temperatures, inlet LBE flow rates, inlet oxygen concentrations and gas/liquid interface oxygen concentrations. A mass transfer correlation for oxygen transport is finally acquired. The simulated results indicate that oxygen transport is mainly influenced by the combined effect of convection and diffusion. Specifically, the mass flow coefficient increases with the increase of mass flow coefficient and LBE temperature. The gas/liquid interface oxygen concentration has little effect on the oxygen mass transfer coefficient in the oxygen transfer device of this study. Comparatively, the smaller inlet oxygen concentration leads to the larger average oxygen mass transfer coefficient and the effects of inlet oxygen concentration become weaker with the increase of flow rate. The numerical data presented in this study represents an essential step to reveal the mechanism of oxygen transport in flowing LBE and provides the theoretical basis for guiding the design of oxygen transfer device in HLM-cooled nuclear reactors.
Research of Steady-State Heat Transfer Performance of Heat Pipe Inside Mobile Heat Pipe Reactor
Authors: Lu Huaichang , Zhou Tao , Liu Wenbin , Mao Shang , Wei Dong , Yao Yao , Gao Tianyu
Published: April 2023

High-temperature heat pipe is an important element in a mobile heat pipe reactor, and the study of the steady-state heat transfer performance of the heat pipe is of great value to the design and safe application of the heat pipe. Based on COMSOL software, a three-dimensional heat pipe model is established to study the effects of the input power of the evaporative section of the heat pipe and the horizontal acceleration of the heat pipe due to its movement on the heat transfer performance of the potassium heat pipe in steady-state operation. The results show that the overall temperature of the outer wall surface of the heat pipe and the axial temperature variation of the center of the heat pipe are less affected by the horizontal acceleration and more affected by the input thermal power within the study range; the thermal resistance of the heat pipe decreases with the increase of the input power of the evaporation section of the heat pipe, and shows a trend of decreasing and then increasing with the increase of the horizontal acceleration.
Three-Dimensional Pin-by-Pin Transient Analysis for PWR-Core
Authors: Qin Junwei , Li Yunzhao
Published: April 2023

To ensure the safety of PWR-core operation, three-dimensional whole-core transient analysis needs to be carried out for the sake of the pin-power distribution. For this purpose, this paper presents “Bamboo-Transient 2.0”, a three-dimensional pin-by-pin transient analysis program. The program adopts a fully-implicit backward method with finite difference for time variable discretization, a method of exponential function expansion nodal (EFEN) SP3 for the neutron transport calculation, and a multi-channel model for the thermal feedback calculation. In addition, Picard iteration is used to couple the neutronics with thermal-feedback, which is intended to guarantee the convergence of coupling iteration at each time step. Moreover, the program can perform parallel computing based on Message Passing Interface (MPI) for the whole-core pin-by-pin transient analysis. This developed program has been applied to two commercial PWRs, viz. AP1000 and CNP1000. Numerical results of this application demonstrate that Bamboo-Transient 2.0 can yield much more refined results than the traditional legacy coarse-mesh neutron-diffusion programs based on assembly homogenization. Its pin-wise distributions of state parameters are reliable and thus can satisfactorily meet the requirements and purpose of safety analysis.
Numerical Simulation of Convective Heat Transfer of CO2 in a Tube Under Supercritical Pressure at Low Reynolds Numbers
Authors: Li Zhihui
Published: April 2023

The supercritical carbon dioxide (S-CO2) Brayton cycle has the advantages of compact layout, simple structure, high thermal efficiency, clean working quality, its application in lead-cooled fast reactor power conversion system helps the miniaturization and modularization of the whole system. The development of an efficient and compact supercritical CO2 heat exchanger has important reference significance for improving the thermal efficiency of the system of lead-cooled fast reactor. Supercritical CO2 can operate in high Reynolds number turbulence and low Reynolds number turbulence in heat exchanger. The convective heat transfer of supercritical pressure CO2 flowing upward and downward in a vertical circular tube (d = 2 mm) at low inlet Reynolds number (Rein = 1970) was numerically simulated by different turbulence models to study the effects of variable properties, buoyancy and thermal acceleration on wall temperature and turbulent kinetic energy. The results showed that the heat transfer deterioration and enhancement occurred at the entrance of the heating section during the upward flow, which was mainly attributed to the influence of buoyancy and heat acceleration on the turbulent kinetic energy distribution. The LB turbulence model was used to simulate the heat transfer phenomenon, which was occurred in the downward flow.
Research of Helium Thermal Power System Based on Lead-Cooled Fast Reactor
Authors: Li Zhihui
Published: April 2023

The Helium Brayton cycle with re-compression has the advantages of compact layout, simple structure, thermal high efficiency, good heat transfer characteristics and small friction characteristics, its application in the power conversion system of the lead-cooled fast reactor and the high temperature gas-cooled reactor helps the miniaturization of the whole system. In this paper, the mathematical model was established for Helium Brayton cycle with re-compression and the 100 MWt lead-cooled fast reactor power system was calculated. The effects of several key factors such as the turbine inlet temperature, the turbine outlet pressure, the high pressure compressor outlet pressure, the low pressure compressor outlet pressure and the recuperator outlet temperature were analyzed. The results show that the turbine outlet pressure, the turbine inlet temperature and the high/low pressure compressor outlet pressure have remarkable effects on thermal efficiency of the system. Thermal efficiency of the system increases first and then decreases with the turbine outlet pressure increasing as well as increases with turbine inlet temperature. The research results of this paper could provide important theoretical reference both for thermal cycle parameters for 100 MWt lead-cooled fast reactor and system design of power cycle based on the lead-cooled fast reactor.
Study on Capiliary Characteristics of Stainless Steel Wire Mesh Wick of Alkali Metal Heat Pipe
Authors: Zhu Yiru , Zhang Luteng , Xi Zhiguo , Ma Zaiyong , Sun Wan , Zhu Longxiang , Pan Liangming
Published: April 2023

The capillary characteristics of the wicks are of great significance to the normal operation of the heat pipe,and this study carried out the wick experiment of vertical reel stainless steel wire mesh in liquid sodium working medium and the visual observation experiment of sodium film in the wire mesh wick. The experimental results show that when the temperature of liquid sodium is about 400 ℃, the capillary phenomenon of stainless steel wire mesh occurs more obviously, and after 450 ℃, the evaporation of sodium is gradually obvious and accompanied by the mass fluctuation of the wire mesh wick. The visual observation experiment of sodium liquid film in the wire mesh found that the wetting and transition point of sodium on the surface of the stainless steel wire mesh was about 410 ℃, which was a good verification of the occurrence of the more obvious capillary phenomenon of the wick at about 400 ℃.
Thermodynamic Equilibrium Analysis of Steam Reforming Reaction of Radioactive Waste Oil
Authors: Wu Xuan , Li Wenyu , Lin Li , Liang Yi , Zhang Jiaheng , Gu Wenlu , Fan Jiheng , Shen EnWei , Xiong KouHong
Published: April 2023

At present, there are much radioactive waste oil temporarily stored in nuclear fuel processing plants, nuclear industry research institutes and operating nuclear power plants in China, which brings great storage pressure and safety risks to the operating nuclear facilities. In this paper, the components analysis of 40# waste oil used in nuclear facilities was carried out, and the elemental composition and chemical composition of the waste oil were obtained. The analysis showed that the main elements in the waste oil were C and H, and the main chemical components were alkanes, alkenes, aromatic hydrocarbons and alcohols with carbon chain length of 10–40. Using Aspen Plus software, the process flow model of waste oil’s steam reforming treatment was established. Based on the components analysis results of the waste oil, organic mixtures such as ethanol, ethane and propane were selected as the model components, and the element composition close to waste oil was obtained by adjusting the proportion of each component. The mixture was used as the source input of Aspen Plus to achieve good simulation results. The experimental results obtained under Pt catalyst at 400 ℃ were in good agreement with the simulation results, which confirmed the validity of the model. The thermodynamic equilibrium analysis of waste oil steam reforming reaction was carried out by using the verified model. The influence of reaction temperature (350–1150 ℃), pressure (0.01–100bar) and water to carbon ratio (0.01–100) on reforming reaction and off gas components in balanced state was studied. The conclusions are as follows: (1) The steam reforming reaction of waste oil has no obvious inhibition when the reaction pressure is less than 1bar, so the reforming reaction should be carried out under the condition of negative pressure less than 1bar; (2) The temperature should be maintained above 750 ℃ to ensure the complete steam reforming reaction; (3) Carbon deposition can be completely eliminated when the water/carbon ratio is higher than 1, and when the water/carbon ratio is higher than 10, the product components do not change with the water/carbon ratio.
Simulation Study of the Neutron Scattering Camera Based on Plastic Scintillator and MPPC
Authors: Li Ji , Shan Qing
Published: April 2023

Nuclear safety has always been the lifeline of the development of the nuclear industry, and the supervision and management of special nuclear materials is a very important part of nuclear safety. By measuring fission neutron generated by the special nuclear materials, the type and position of special nuclear materials can be determined. In this paper, a neutron scattering camera (NSC) based on plastic scintillator and MPPC was designed to detect the fission neutron in the n-γ mixed field, and then to realize the localization and discrimination of fission materials. The designed NSC contains two layers of detector arrays. The first and second layers are consisted of five and nine detection units, respectively. In order to discriminate neutrons and gamma-rays, EJ-276 plastic scintillator is chosen as the detection medium because of its PSD performance. At the same time, MPPC was used to collect the fluorescence generated in the scintillator. For optimizing the NSC, the Geant4 Monte Carlo simulation toolkit is used to study the whole detection process of the NSC. In the simulation, the factors affecting image reconstruction in neutron source image reconstruction have studied by simulation. The influences of the thickness and radius of the detection units in two layers, the distance between two layers on the image reconstruction were studied in detail. According to the simulation results, the thickness of front detector unit, radius of detector unit, thickness of back detector unit and distance between two layers were determined to be 3 cm, 5 cm, 8 cm and 50 cm, respectively.
Vector-valued invariant means
Authors: Badora Roman
Published: April 2023

In the paper, we will present some important results from the theory of vector-valued invariant means. Discussing the results contained in the author’s paper Badora (Ann Pol Math 58:147–159, 1993), we will add new facts that were previously not published.
Modeling and ballistic tests of selected soft point projectiles in a water medium
Authors: Żochowski Paweł , Pacek Dawid , Bednarczyk Ewa , Bajkowski Marcin , Grygoruk Roman , Magier Mariusz , Szczurowski Krzysztof , Jasiński Marcin
Published: April 2023

Methods used nowadays in forensic laboratories allow to stop some kinds of projectiles with degree of deformation which lets to use them for comparing traces to projectiles found on the crime scene. However they are not useful for every type of projectiles. Comparative physical tests are enough to indicate the best method for soft catching projectiles. For this aim point of view no modeling needed. The paper presents the results of ballistic tests of impact of chosen types of soft point projectiles into water. The behavior of projectiles of various shapes, with different kinetic energy, was analyzed. On the basis of the obtained results, the projectiles with the highest susceptibility to deformation were identified. Research works described in the paper were performed within the framework of the project Laboratory stand for stopping high-energy projectiles financed from the National Centre for Research and Development (Agreement no. DOB-BIO10/04/02/ 2019). The project is implemented in cooperation with Warsaw University of Technology, Military Institute of Armament Technology and Tebbex 2 since 2019 to 2022.
Norms of structured random matrices
Authors: Adamczak Radosław , Prochno Joscha , Strzelecka Marta , Strzelecki Michał
Published: April 2023

For $$m,n\in \mathbb {N}$$

m
,
n
∈
N

, let $$X=(X_{ij})_{i\le m,j\le n}$$

X
=

(

X

ij

)

i
≤
m
,
j
≤
n

be a random matrix, $$A=(a_{ij})_{i\le m,j\le n}$$

A
=

(

a

ij

)

i
≤
m
,
j
≤
n

a real deterministic matrix, and $$X_A=(a_{ij}X_{ij})_{i\le m,j\le n}$$

X
A

=

(

a

ij

X

ij

)

i
≤
m
,
j
≤
n

the corresponding structured random matrix. We study the expected operator norm of $$X_A$$

X
A

considered as a random operator between $$\ell _p^n$$

ℓ
p
n

and $$\ell _q^m$$

ℓ
q
m

for $$1\le p,q \le \infty $$

1
≤
p
,
q
≤
∞

. We prove optimal bounds up to logarithmic terms when the underlying random matrix X has i.i.d. Gaussian entries, independent mean-zero bounded entries, or independent mean-zero $$\psi _r$$

ψ
r

($$r\in (0,2]$$

r
∈
(
0
,
2
]

) entries. In certain cases, we determine the precise order of the expected norm up to constants. Our results are expressed through a sum of operator norms of Hadamard products $$A\circ A$$

A
∘
A

and $$(A\circ A)^T$$

(
A
∘
A
)

T

.
Towards a fast PET/MRI protocol for breast cancer imaging: maintaining diagnostic confidence while reducing PET and MRI acquisition times
Authors: Jannusch Kai , Lindemann Maike E. , Bruckmann Nils Martin , Morawitz Janna , Dietzel Frederic , Pomykala Kelsey L. , Herrmann Ken , Bittner Ann-Kathrin , Hoffmann Oliver , Mohrmann Svjetlana , Umutlu Lale , Antoch Gerald , Quick Harald H. , Kirchner Julian
Published: April 2023

Objectives

To investigate the diagnostic feasibility of a shortened breast PET/MRI protocol in breast cancer patients.

Methods

Altogether 90 women with newly diagnosed T1tumor-staged (T1ts) and T2tumor-staged (T2ts) breast cancer were included in this retrospective study. All underwent a dedicated comprehensive breast [18F]FDG-PET/MRI. List-mode PET data were retrospectively reconstructed with 20, 15, 10, and 5 min for each patient to simulate the effect of reduced PET acquisition times. The SUVmax/mean of all malign breast lesions was measured. Furthermore, breast PET data reconstructions were analyzed regarding image quality, lesion detectability, signal-to-noise ratio (SNR), and image noise (IN). The simultaneously acquired comprehensive MRI protocol was then shortened by retrospectively removing sequences from the protocol. Differences in malignant breast lesion detectability between the original and the fast breast MRI protocol were evaluated lesion-based. The 20-min PET reconstructions and the original MRI protocol served as reference.

Results

In all PET reconstructions, 127 congruent breast lesions could be detected. Group comparison and T1ts vs. T2ts subgroup comparison revealed no significant difference of subjective image quality between 20, 15, 10, and 5 min acquisition times. SNR of qualitative image evaluation revealed no significant difference between different PET acquisition times. A slight but significant increase of IN with decreasing PET acquisition times could be detected. Lesion SUVmax group comparison between all PET acquisition times revealed no significant differences. Lesion-based evaluation revealed no significant difference in breast lesion detectability between original and fast breast MRI protocols.

Conclusions

Breast [18F]FDG-PET/MRI protocols can be shortened from 20 to below 10 min without losing essential diagnostic information.

Key Points

• A highly accurate breast cancer evaluation is possible by the shortened breast [18F]FDG-PET/MRI examination protocol.

• Significant time saving at breast [18F]FDG-PET/MRI protocol could increase patient satisfaction and patient throughput for breast cancer patients at PET/MRI.
Investigation of turbulent superstructures in Rayleigh–Bénard convection by Lagrangian particle tracking of fluorescent microspheres
Authors: Weiss Stephan , Schanz Daniel , Erdogdu Ahmed Oguzhan , Schröder Andreas , Bosbach Johannes
Published: April 2023

We present spatially and temporally resolved velocity and acceleration measurements of turbulent Rayleigh–Bénard convection (RBC) in the entire fluid sample of square horizontal cross section with length $$L=320$$

L
=
320

 mm and height $$H=20$$

H
=
20

 mm, resulting in an aspect ratio of $$\Gamma =H/L=16$$

Γ
=
H
/
L
=
16

. The working fluid was water with a Prandtl number of Pr=7 and the Rayleigh number was set to $${\text{Ra}}= 1.1\times 10^6$$

Ra
=
1.1
×

10
6

. In order to minimize surface reflections, we used fluorescent polyethylene microspheres as tracer particles that were imaged at a rate of 19 Hz by six cameras. From the images, the particle positions, velocities, and accelerations were determined via the ‘Shake-The-Box’ (STB) Lagrangian particle tracking algorithm. With this approach, we could simultaneously track more than 300,000 particles and hence study the resulting turbulent structures in the Eulerian and Lagrangian frames while resolving the smallest spatial and temporal scales of the flow.
Application of gene expression programming for seasonal rainfall forecasting in Western Australia using potential climate indices
Authors: Islam Farhana , Imteaz Monzur Alam
Published: April 2023

This study presents the development of rainfall forecast models using potential climate indices for the Kimberley region of Western Australia, using 100 years of rainfall and climate indices data for four rainfall stations. Three different modeling techniques: multiple linear regression (MLR), autoregressive moving average with exogenous input (ARIMAX), and gene-expression programming (GEP) were applied to develop prediction models. Preliminary analysis suggests that Western Tropical Indian Ocean (WTIO) and Southern Oscillation Index (SOI) have significant impacts on summer rainfall generation for the region. Developed models’ performances were evaluated using Pearson correlation coefficient ($$r$$
r
), root mean square error ($$RMSE$$

RMSE

), mean absolute error $$(MAE)$$

(
M
A
E
)

, Nash–Sutcliffe efficiency $$(NSE)$$

(
N
S
E
)

, and refined Willmot index of agreement ($${d}_{r}$$

d
r

). It is found that the GEP model exclusively outperforms the other two alternatives. In the calibration period, the GEP model resulted in a Pearson correlation coefficient (r) values ranging from 0.76 to 0.85, which are significantly higher than that achieved from MLR (0.32 to 0.44) and ARIMAX (0.53 to 0.83) models, while for the validation period, the correlation values for the models ranged from 0.74 to 0.87 for GEP, 0.35 to 0.51 for MLR and 0.59 to 0.77 for ARIMAX models. Considering other statistical error statistics it can be concluded that the GEP model is the best representative seasonal rainfall forecasting model for the region.
Optical coherence tomography combined with convolutional neural networks can differentiate between intrahepatic cholangiocarcinoma and liver parenchyma ex vivo
Authors: Wolff Laura I. , Hachgenei Enno , Goßmann Paul , Druzenko Mariia , Frye Maik , König Niels , Schmitt Robert H. , Chrysos Alexandros , Jöchle Katharina , Truhn Daniel , Kather Jakob Nikolas , Lambertz Andreas , Gaisa Nadine T. , Jonigk Danny , Ulmer Tom F. , Neumann Ulf P. , Lang Sven A. , Amygdalos Iakovos
Published: April 2023

Purpose

Surgical resection with complete tumor excision (R0) provides the best chance of long-term survival for patients with intrahepatic cholangiocarcinoma (iCCA). A non-invasive imaging technology, which could provide quick intraoperative assessment of resection margins, as an adjunct to histological examination, is optical coherence tomography (OCT). In this study, we investigated the ability of OCT combined with convolutional neural networks (CNN), to differentiate iCCA from normal liver parenchyma ex vivo.

Methods

Consecutive adult patients undergoing elective liver resections for iCCA between June 2020 and April 2021 (n = 11) were included in this study. Areas of interest from resection specimens were scanned ex vivo, before formalin fixation, using a table-top OCT device at 1310 nm wavelength. Scanned areas were marked and histologically examined, providing a diagnosis for each scan. An Xception CNN was trained, validated, and tested in matching OCT scans to their corresponding histological diagnoses, through a 5 × 5 stratified cross-validation process.

Results

Twenty-four three-dimensional scans (corresponding to approx. 85,603 individual) from ten patients were included in the analysis. In 5 × 5 cross-validation, the model achieved a mean F1-score, sensitivity, and specificity of 0.94, 0.94, and 0.93, respectively.

Conclusion

Optical coherence tomography combined with CNN can differentiate iCCA from liver parenchyma ex vivo. Further studies are necessary to expand on these results and lead to innovative in vivo OCT applications, such as intraoperative or endoscopic scanning.
Effectiveness of physical therapy in axillary web syndrome after breast cancer: a systematic review and meta-analysis
Authors: González-Rubino Jesús Baltasar , Vinolo-Gil Maria Jesus , Martín-Valero Rocío
Published: April 2023

Background

The axillary web syndrome (AWS) is a surgical breast cancer sequel that limits the functionality of the patient and delays the protocol times of application of cancer treatments. This implies a long period of discomfort and limitations for the user.

Objective

To investigate the different physiotherapy treatments for the AWS and how effective they are.

Methods

A systematic review based on PRISMA protocol and registered in PROSPERO (CRD42021281354) was conducted. The research was performed using PubMed, Scopus, CINAHL, PEDro, and Web of Science databases during January 2022 and March 2022. All randomized controlled trials and controlled clinical trials were included in this review.

Results

A total of 188 articles were identified, with 9 studies selected for the systematic review. These studies basically propose treatments based on exercises and stretching, manual therapy, and the combination of manual therapy and exercises.

Conclusions

Exercise and stretching are the most effective therapies within the field of physiotherapy for the rehabilitation of axillary web syndrome. They restore range of motion faster, reduce pain, improve quality of life, and reduce disabilities. Manual therapy, scar massage, and myofascial release could help improve outcomes but with worse results. The meta-analysis conclusion is that pain is the only outcome with a significant reduction after the application of physiotherapy treatments − 0.82 [− 1.67; 0.03]. This conclusion is drawn from the only three studies with small sample sizes.
Investigation of the best effective fold of data augmentation for training deep learning models for recognition of contiguity between mandibular third molar and inferior alveolar canal on panoramic radiographs
Authors: Papasratorn Dhanaporn , Pornprasertsuk-Damrongsri Suchaya , Yuma Suraphong , Weerawanich Warangkana
Published: April 2023

Objectives

This study aimed to train deep learning models for recognition of contiguity between the mandibular third molar (M3M) and inferior alveolar canal using panoramic radiographs and to investigate the best effective fold of data augmentation.

Materials and methods

The total of 1800 M3M cropped images were classified evenly into contact and no-contact. The contact group was confirmed with CBCT images. The models were trained from three pretrained models: AlexNet, VGG-16, and GoogLeNet. Each pretrained model was trained with the original cropped panoramic radiographs. Then the training images were increased fivefold, tenfold, 15-fold, and 20-fold using data augmentation to train additional models. The area under the receiver operating characteristic curve (AUC) of the 15 models were evaluated.

Results

All models recognized contiguity with AUC from 0.951 to 0.996. Ten-fold augmentation showed the highest AUC in all pretrained models; however, no significant difference with other folds were found. VGG-16 showed the best performance among pretrained models trained at the same fold of augmentation. Data augmentation provided statistically significant improvement in performance of AlexNet and GoogLeNet models, while VGG-16 remained unchanged.

Conclusions

Based on our images, all models performed efficiently with high AUC, particularly VGG-16. Ten-fold augmentation showed the highest AUC by all pretrained models. VGG-16 showed promising potential when training with only original images.

Clinical relevance

Ten-fold augmentation may help improve deep learning models’ performances. The variety of original data and the accuracy of labels are essential to train a high-performance model.
Brain activity during cybersickness: a scoping review
Authors: Chang Eunhee , Billinghurst Mark , Yoo Byounghyun
Published: April 2023

Virtual reality (VR) experiences can cause a range of negative symptoms such as nausea, disorientation, and oculomotor discomfort, which is collectively called cybersickness. Previous studies have attempted to develop a reliable measure for detecting cybersickness instead of using questionnaires, and electroencephalogram (EEG) has been regarded as one of the possible alternatives. However, despite the increasing interest, little is known about which brain activities are consistently associated with cybersickness and what types of methods should be adopted for measuring discomfort through brain activity. We conducted a scoping review of 33 experimental studies in cybersickness and EEG found through database searches and screening. To understand these studies, we organized the pipeline of EEG analysis into four steps (preprocessing, feature extraction, feature selection, classification) and surveyed the characteristics of each step. The results showed that most studies performed frequency or time-frequency analysis for EEG feature extraction. A part of the studies applied a classification model to predict cybersickness indicating an accuracy between 79 and 100%. These studies tended to use HMD-based VR with a portable EEG headset for measuring brain activity. Most VR content shown was scenic views such as driving or navigating a road, and the age of participants was limited to people in their 20 s. This scoping review contributes to presenting an overview of cybersickness-related EEG research and establishing directions for future work.
Incidentally exploring natural course of a rare entity: representative case for rosette-forming glioneuronal tumors
Authors: Altunbüker Hira , Hinz Felix , Sahm Felix , Brehmer Stefanie , Wenz Holger
Published: April 2023

Rosette-forming glioneuronal tumors (RGNT) are extremely rare mostly benign tumors of the central nervous system, which are often studied for its histological aspects despite relatively small numbers of clinical especially radiological knowledge.

Despite the increasing number of publications on different localizations and treatment protocols, the morphologic and temporal development process of this rare tumor entity is not clear. We were able to coincidentally observe the entire course of the tumor growth of a RGNT on subsequent MRI examinations in a typical case with mild clinical symptoms and no other neurological illnesses, thus possible clinical complications were prevented.
A systematic review of social network sentiment analysis with comparative study of ensemble-based techniques
Authors: Tiwari Dimple , Nagpal Bharti , Bhati Bhoopesh Singh , Mishra Ashutosh , Kumar Manoj
Published: April 2023

Sentiment Analysis (SA) of text reviews is an emerging concern in Natural Language Processing (NLP). It is a broadly active method for analyzing and extracting opinions from text using individual or ensemble learning techniques. This field has unquestionable potential in the digital world and social media platforms. Therefore, we present a systematic survey that organizes and describes the current scenario of the SA and provides a structured overview of proposed approaches from traditional to advance. This work also discusses the SA-related challenges, feature engineering techniques, benchmark datasets, popular publication platforms, and best algorithms to advance the automatic SA. Furthermore, a comparative study has been conducted to assess the performance of bagging and boosting-based ensemble techniques for social network SA. Bagging and Boosting are two major approaches of ensemble learning that contain various ensemble algorithms to classify sentiment polarity. Recent studies recommend that ensemble learning techniques have the potential of applicability for sentiment classification. This analytical study examines the bagging and boosting-based ensemble techniques on four benchmark datasets to provide extensive knowledge regarding ensemble techniques for SA. The efficiency and accuracy of these techniques have been measured in terms of TPR, FPR, Weighted F-Score, Weighted Precision, Weighted Recall, Accuracy, ROC-AUC curve, and Run-Time. Moreover, comparative results reveal that bagging-based ensemble techniques outperformed boosting-based techniques for text classification. This extensive review aims to present benchmark information regarding social network SA that will be helpful for future research in this field.
Evaluation of long-chain omega-3 canola oil on Atlantic salmon growth, performance, and essential fatty acid tissue accretion across the life cycle: a review
Authors: Davis Barbara A , Devine Malcolm D
Published: April 2023

Aquaculture plays an important role in providing protein and fatty acids to meet human nutritional requirements. The finite supply of marine ingredients has led to increased use of vegetable oils in aquafeed. While these oils can meet energy and growth needs, they lack nutritionally required ω3 long-chain polyunsaturated fatty acids (ω3 LCPUFAs). Development of land-based alternative oil sources to safeguard global aquaculture production, while meeting the nutritional needs of both fish and human consumers, is critical. This review summarizes studies using a new land-based ω3 LCPUFA canola oil in fish feed to support both energy and ω3 LCPUFA requirements of Atlantic salmon during each phase of the life cycle, while producing fish with adequate ω3 LCPUFA content to meet human nutritional needs. In all cases, growth and performance were comparable to fish fed conventional fish-oil-based diets; no adverse effects were attributed to the use of ω3 canola oil. Fatty acid deposition in muscle (fillet) reflected feed composition, resulting in accumulation of alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) and a low ω6:ω3 ratio, making salmon fed ω3 LCPUFA canola oil a sustainable source of these nutrients for human consumption. Additionally, reduced melanin deposits were observed in fish fed ω3 LCPUFA canola oil.
Modular Homes as a New Form of Accommodation to Tackle Homelessness: A Case Study From Cambridge, England
Authors: Ehwi Richmond Juvenile , Oti-Sarpong Kwadwo , Burgess Gemma , Lenhard Johannes , Meng Eana
Published: April 2023

In England, provision of temporary accommodation for people experiencing homelessness has often entailed using traditional construction approaches to deliver housing. However, recent experiments are using modular homes to provide temporary accommodation, accompanied by support services for people experiencing homelessness. Given the early nature of these trials, it is unclear what impacts these modular homes have on their occupants and how these projects in turn impact surrounding residents and businesses. We present a case study of the first modular homes for people experiencing homelessness in Cambridge, England, drawing on longitudinal interviews with the six residents occupying these homes. We found that the physical features of the homes, coupled with wrap-around support services, yielded positive short- and mid-term outcomes for occupants, including improved management of their substance use and money, skills development and readiness for employment, social relations, and a burgeoning sense of community, safety, and security. These positive outcomes have spurred wider interest, including the incorporation of modular homes as alternative temporary accommodation in the Homelessness and Rough Sleeping Strategy of Cambridge City Council, alongside a growing research interest in modular homes and other new schemes by the national government. We argue for further empirical studies of the impacts of different modular home projects, including those that admit more diverse resident cohorts and offer different accommodation types to establish a clear methodology for future modular homes projects in England and beyond.
Rigid toric matrix Schubert varieties
Authors: Portakal Irem
Published: April 2023

Fulton proves that the matrix Schubert variety $$\overline{X_{\pi }} \cong Y_{\pi } \times \mathbb {C}^q$$

X
π

¯

≅

Y
π

×

C

q

can be defined via certain rank conditions encoded in the Rothe diagram of $$\pi \in S_N$$

π
∈

S
N

. In the case where $$Y_{\pi }:={{\,\textrm{TV}\,}}(\sigma _{\pi })$$

Y
π

:
=

TV

(

σ
π

)

is toric (with respect to a $$(\mathbb {C}^*)^{2N-1}$$

(

C

∗

)

2
N
-
1

action), we show that it can be described as a toric (edge) ideal of a bipartite graph $$G^{\pi }$$

G
π

. We characterize the lower dimensional faces of the associated so-called edge cone $$\sigma _{\pi }$$

σ
π

explicitly in terms of subgraphs of $$G^{\pi }$$

G
π

and present a combinatorial study for the first-order deformations of $$Y_{\pi }$$

Y
π

. We prove that $$Y_{\pi }$$

Y
π

is rigid if and only if the three-dimensional faces of $$\sigma _{\pi }$$

σ
π

are all simplicial. Moreover, we reformulate this result in terms of the Rothe diagram of $$\pi $$
π
.