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Predicting impact strength of perforated targets using artificial neural networks trained on FEM-generated datasets

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Defence Technology（防务技术） 2024年第2期32卷 32-44页

作者： nikita Kazarinov Aleksandr Khvorov Saint Petersburg State University Saint Petersburg 199034Russia Higher School of Economics Saint Petersburg 190121Russia

The paper considers application of artificial neural networks(ANNs)for fast numerical evaluation of a residual impactor velocity for a family of perforated PMMA(Polymethylmethacrylate)targets.The ANN models were trained using sets of numerical results on impact of PMMA plates obtained via dynamic FEM coupled with incubation time fracture criterion.The developed approach makes it possible to evaluate the impact strength of a particular target configuration without complicated FEM calculations which require considerable computational resources.Moreover,it is shown that the ANN models are able to predict results for the configurations which cannot be processed using the developed FEM routine due to numerical instabilities and errors:the trained neural network uses information from successful computations to obtain results for the problematic cases.A simple static problem of a perforated plate deformation is discussed prior to the impact problem and preferable ANN architectures are presented for both problems.Some insight into the perforation pattern optimization using a genetic algorithm coupled with the ANN is also made and optimized perforation patterns which theoretically enhance the target impact strength are constructed.

关键词： Machine learning Impact Dynamic fracture FEM Mesh distortion Optimization

A rare co-occurrence of spontaneous pneumomediastinum,pneumothorax,and pneumoperitoneum:Macklin effect

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World Journal of Emergency Medicine 2024年第3期15卷 246-248页

作者： Renaldo Pavrey nikita Makwana Nisha Das Centre for Accident and Emergency Medicine Nanavati Max Super Specialty HospitalMumbai 400050India

Spontaneous pneumomediastinum (SPM) is characterized by free air or gas located within the mediastinum that is not associated with any noticeable cause,such as chest trauma,intrathoracic infections,surgery,other organ... 详细信息

关键词： rupture trauma infections

Comparison of extraction abilities of deep eutectic solvents and aqueous acid solutions for extraction of rare earths and transition metals

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Journal of Rare Earths 2024年第6期42卷 1157-1164,I0006页

作者： Svetlana Drogobuzhskaya Margarita Frolova Andrey Shishov nikita Tsvetov Tananaev Institute of Chemistry-Subdivision of the Federal Research Centre《Kola Science Centre of the Russian Academy of Sciences》 18420926a AcademgorodokApatityRussia Murmansk State Technical University 183010Sportivnaja str.13MurmanskRussia Department of Analytical Chemistry Institute of ChemistrySaint Petersburg State UniversitySpbSU.1990347/9 Universitetskaya embSt.Petersburg Russia

In recent years,deep eutectic solvents have attracted increasing interest as effective extractants for the separation of both organic substances and metals from various objects.Acid-based deep eutectic solvents are most often used as extractants for the extraction of metals.In this work,for the first time,the extraction efficiency of transition metals and rare earth elements(Y,Zr,Nb,La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu,Hf and Ta)from mining tailings and Na,K,Ca,Mg,Cu,Fe,Mn,Pb,Ba,Ni and Sr from biodiesel samples using acidic deep eutectic solvents and saturated aqueous solutions of the same acids(malonic,malic,tartaric and citric)is compared.For this,deep eutectic solvents based on acids and their aqueous saturated solutions were prepared and studied.The prepared mixtures were analyzed by IR spectroscopy to confirm the formation of eutectic solvents.Properties such as the density and viscosity of the resulting mixtures were also investigated,as this can be of key importance for the efficiency of metal extraction.The extraction of rare earth metals from mining tailings took a long time(up to several days),while the extraction of metals from fuel took no more than 30 min.Atomic emission spectral methods were used as an analysis method.It is shown that the extraction efficiency with aqueous solutions is better than that with eutectic solvents,which casts doubt on the need for deep eutectic solvents use in this area.

关键词： Deepeutectic solvent Metal separation Elemental analysis Rare earth metals Biodiesel

Using microglia-derived extracellular vesicles to capture diversity of microglial activation phenotypes following neurological injury

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Neural Regeneration Research 2024年第8期19卷 1633-1634页

作者： Austyn D.Roseborough nikita Ollen-Bittle Shawn NWhitehead Vulnerable Brain Laboratory Department of Anatomy&Cell BiologySchulich School of Medicine&DentistryLondonOHCanada

Microglia are one of the three glial cell populations in the central nervous system(CNS),along with astrocytes and oligodendrocytes.While microglia are unique among brain cells due to their hematologic origin and perf... 详细信息

关键词： neurological cytes activation

Connecting cellular mechanisms and extracellular vesicle cargo in traumatic brain injury

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Neural Regeneration Research 2024年第10期19卷 2119-2131页

作者： nikita Ollen-Bittle Austyn D.Roseborough Wenxuan Wang Jeng-liang D.Wu Shawn N.Whitehead Department of Anatomy and Cell Biology Western UniversityLondonONCanada Schulich School of Medicine and Dentistry Western UniversityLondonONCanada Deparment of Clinical Neurological Sciences Western UniversityLondonONCanada

Traumatic brain injury is followed by a cascade of dynamic and complex events occurring at the cellular level. These events include: diffuse axonal injury, neuronal cell death, blood-brain barrier break down, glial activation and neuroinflammation, edema, ischemia, vascular injury, energy failure, and peripheral immune cell infiltration. The timing of these events post injury has been linked to injury severity and functional outcome. Extracellular vesicles are membrane bound secretory vesicles that contain markers and cargo pertaining to their cell of origin and can cross the blood-brain barrier. These qualities make extracellular vesicles intriguing candidates for a liquid biopsy into the pathophysiologic changes occurring at the cellular level post traumatic brain injury. Herein, we review the most commonly reported cargo changes in extracellular vesicles from clinical traumatic brain injury samples. We then use knowledge from animal and in vitro models to help infer what these changes may indicate regrading cellular responses post traumatic brain injury. Future research should prioritize labeling extracellular vesicles with markers for distinct cell types across a range of timepoints post traumatic brain injury.

关键词： axonal injury biomarkers blood-brain barrier chronic traumatic encephalopathy extracellular vesicles glial activation neuroinflammation traumatic brain injury

Assessment of the ecological state of haplic chernozem contaminated by oil,fuel oil and gasoline after remediation

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Petroleum Research 2024年第1期9卷 155-164页

作者： Anna Ruseva Tatiana Minnikova Sergey Kolesnikov Dmitry Trufanov nikita Minin Sofya Revina Vladimir Gayvoronsky Southern Federal University Academy of Biology and Biotechnology344090Rostov-on-DonRussia

The intensive use of petroleum hydrocarbon products has made them priority environmental pollutants.When petroleum hydrocarbons enter the soil,a change in physical,chemical,and biological properties is observed.The natural restoration of oil-contaminated soils is a lengthy process;therefore,remediation is often required.The aim of this study is to assess the change in the ecological state of haplic chernozem soil contaminated with oil,fuel oil,and gasoline after remediation.The indicators of soil biological activity,such as phytotoxicity(germination,length of shoots and roots),the activity of oxidoreductase enzymes(catalase and dehydrogenases),and the total number of bacteria were studied.The effects of nitroammophoska fertilizer,sodium humate,biochar,and the biofertilizer“Baikal EM-1”on the ecological state of soils contaminated with oil,fuel oil,and gasoline were studied.Pollution with oil,fuel oil,and gasoline decreased the values of all biological indicators.The most sensitive indicator was the length of radish roots in soils polluted with oil,gasoline,and fuel oil after remediation with nitroammophoska and Baikal EM-1 addition.The length of roots was the most sensitive indicator when remediation was performed with biochar and sodium humate added to soil contaminated with oil and gasoline,and with contamination of haplic chernozem soil with fuel oil,the total number of bacteria was the most sensitive indicator.The most effective ameliorant to phytotoxicity indicators for oil pollution was a 1 D dose of biochar,for fuel oil it was 1 D biochar and 2 D sodium humate,and for gasoline it was a 2 D dose of biochar and Baikal EM-1.All ameliorants at most of the studied doses increased dehydrogenase activity,but increased catalase activity only in some cases.An increase in the total number of bacteria in oil-contaminated soils was promoted by biochar and nitroammophoska at a dose of 2 D.Nitroammophoska was the most effective in ameliorant in soils contaminated with fuel oil;in soils polluted with gasoline,all doses o

关键词： Pollution Petroleum hydrocarbons Haplic chernozem Ameliorant dose Biological indicators Soil properties

Robust State Estimation for an Electricity-Gas-Heat Integrated Energy System Considering Dynamic Characteristics

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Protection and Control of Modern Power Systems 2024年第1期9卷 65-80页

作者： Jianshu Yu Dechang Yang Jinye Cao Payman Dehghanian nikita Tomin 不详 College of Information and Electrical Engineering China Agricultural UniversityBeijing 100084China China Agricultural University

The data for an energy management system(EMS)in an integrated energy system(IES)is obtained through state estimation.This is then the basis for optimal scheduling,protection and control.At present,the dynamic models of gas and heat networks are rarely considered in such state estimation,and the method lacks robustness.This paper develops dynamic state estimation models for gas and heat networks,and proposes a unified method for the electricity-gas-heat network,one which takes into account robustness while ensuring accuracy.First,the state transition equations in matrix form are formulated according to finite difference models consid-ering the dynamic characteristics of the gas and heat net-works.Then,combined with a quasi-steady state model of the electric power system,a unified state estimation method and multi-time-scale measurement strategy in the Kalman filter framework are proposed.In addition,the prediction accuracies of the electric power and gas systems are improved through adaptive adjustment.The kernel density estimation method is used to adjust the measurement weights and filter out bad data to ensure robust state estimation.Finally,simulation results show that the proposed method not only can improve the estimation accuracy by improving prediction accuracy,but also is robust to various types of bad data.

关键词： estimation prediction unified

Large-scale error-tolerant programmable interferometer fabricated by femtosecond laser writing

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Photonics Research 2024年第3期12卷 I0028-I0040页

作者： ILYA KONDRATYEV VERONIKA IVANOVA SUREN FLDZHYAN ARTEM ARGENCHIEV nikita KOSTYUCHENKO SERGEY ZHURAVITSKII NIKOLAY SKRYABIN IVAN DYAKONOV MIKHAIL SAYGIN STANISLAV STRAUPE ALEXANDER KORNEEV SERGEI KULIK Quantum Technology Centre and Faculty of Physics M.V.Lomonosov Moscow State UniversityMoscow 119991Russia Russian Quantum Center Moscow 121205Russia Laboratory of Quantum Engineering of Light South Ural State UniversityChelyabinsk 454080Russia

We introduce a programmable eight-port interferometer with the recently proposed error-tolerant architecture capable of performing a broad class of transformations.The interferometer has been fabricated with femtosecond laser writing,and it is the largest programmable interferometer of this kind to date.We have demonstrated its advantageous error tolerance by showing an operation in a broad wavelength range from 920 to 980 nm,which is particularly relevant for quantum photonics due to efficient photon sources existing in this wavelength range.Our work highlights the importance of developing novel architectures of programmable photonics for information processing.

关键词： interferometer laser femtosecond

考虑可平移负荷和智能软开关的主动配电网故障恢复方法

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电力科学与技术学报 2024年第1期39卷 183-192页

作者：杨德昌吴燕 Pandzic Hrvoje Tomin nikita 中国农业大学信息与电气工程学院北京100083 中国人民大学新校区建设办公室北京100872 萨格勒布大学电气与计算机工程学院萨格勒布10000 俄罗斯科学院西伯利亚分院能源研究所新西伯利亚630090

在配电网发生故障后,主动配电网能够实现用户侧参与功率的实时供需平衡,满足故障后的负荷恢复。用户参与配电网的调度也是提升故障后负荷恢复比例的途径之一,可平移负荷具有较强的可控性,有效提升了主动配电网的灵活性,智能软开关等新... 详细信息

在配电网发生故障后,主动配电网能够实现用户侧参与功率的实时供需平衡,满足故障后的负荷恢复。用户参与配电网的调度也是提升故障后负荷恢复比例的途径之一,可平移负荷具有较强的可控性,有效提升了主动配电网的灵活性,智能软开关等新兴可控设备的接入,也使负荷的快速供电成为可能。本文建立了考虑可平移负荷和智能软开关的主动配电网故障恢复模型,并考虑了负荷的重要性系数。通过改进的IEEE 33节点算例进行仿真分析,构建单一故障、多点故障、短时故障的场景,验证了本文所提出方法的有效性以及可控装置对故障后负荷恢复量的提升。

关键词：主动配电网故障恢复可平移负荷智能软开关重要性系数