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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)*** ANN models were trained using sets of numerical results on impact of PMMA plates obtained via dynamic FEM coupled with incubation time fracture *** developed approach makes it possible to evaluate the impact strength of a particular target configuration without complicated FEM calculations which require considerable computational ***,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 *** 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

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 ***-based deep eutectic solvents are most often used as extractants for the extraction of *** 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 *** this,deep eutectic solvents based on acids and their aqueous saturated solutions were prepared and *** prepared mixtures were analyzed by IR spectroscopy to confirm the formation of eutectic *** 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 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 *** emission spectral methods were used as an analysis *** 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

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

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 *** microglia are unique among brain cells due to their hematologic origin and perform immune function... 详细信息

关键词： neurological cytes activation

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 *** is then the basis for optimal scheduling,protection and *** present,the dynamic models of gas and heat networks are rarely considered in such state estimation,and the method lacks *** 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 ***,the state transition equations in matrix form are formulated according to finite difference models consid-ering the dynamic characteristics of the gas and heat ***,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 *** addition,the prediction accuracies of the electric power and gas systems are improved through adaptive *** kernel density estimation method is used to adjust the measurement weights and filter out bad data to ensure robust state ***,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

Machine learning prediction of methane,ethane,and propane solubility in pure water and electrolyte solutions:Implications for stray gas migration modeling

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Acta Geochimica 2024年第5期43卷 971-984页

作者： Ghazal Kooti Reza Taherdangkoo Chaofan Chen nikita Sergeev Faramarz Doulati Ardejani Tao Meng Christoph Butscher Institute of Geotechnics TU Bergakademie FreibergGustav-Zeuner-Str.109599 FreibergGermany Department of Petroleum Engineering Amirkabir University of TechnologyTehranIran Freiberg Center for Water Research ZeWaF TU Bergakademie Freiberg09599 FreibergGermany School of Mining College of EngineeringUniversity of TehranTehranIran Taiyuan University of Science and Technology Taiyuan 030024China

Hydraulic fracturing is an effective technology for hydrocarbon extraction from unconventional shale and tight gas reservoirs.A potential risk of hydraulic fracturing is the upward migration of stray gas from the deep subsurface to shallow *** stray gas can dissolve in groundwater leading to chemical and biological reactions,which could negatively affect groundwater quality and contribute to atmospheric *** knowledge oflight hydrocarbon solubility in the aqueous environment is essential for the numerical modelling offlow and transport in the ***,we compiled a database containing 2129experimental data of methane,ethane,and propane solubility in pure water and various electrolyte solutions over wide ranges of operating temperature and *** machine learning algorithms,namely regression tree(RT)and boosted regression tree(BRT)tuned with a Bayesian optimization algorithm(BO)were employed to determine the solubility of *** predictions were compared with the experimental data as well as four well-established thermodynamic *** analysis shows that the BRT-BO is sufficiently accurate,and the predicted values agree well with those obtained from the thermodynamic *** coefficient of determination(R2)between experimental and predicted values is 0.99 and the mean squared error(MSE)is 9.97×10^(-8).The leverage statistical approach further confirmed the validity of the model developed.

关键词： Gas solubility Hydraulic fracturing Thermodynamic models Regression tree Boosted regression tree Groundwater contamination

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 *** petroleum hydrocarbons enter the soil,a change in physical,chemical,and biological properties is *** natural restoration of oil-contaminated soils is a lengthy process;therefore,remediation is often *** 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 *** 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 *** 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 *** with oil,fuel oil,and gasoline decreased the values of all biological *** 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 *** 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 *** 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 *** ameliorants at most of the studied doses increased dehydrogenase activity,but increased catalase activity only in some *** increase in the total number of bacteria in oil-contaminated soils was promoted by biochar and nitroammophoska at a dose of 2 *** was the most effective in ameliorant in soils contaminated with fuel

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

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

Analysis of the urethral stricture score and patient-related factors as predictors of outcomes following oral mucosal graft urethroplasty

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Asian Journal of Urology 2024年第3期11卷 473-479页

作者： nikita Shrivastava Rahul Jena Deepak Prakash Bhirud Mahendra Singh Gautam Ram Choudhary Arjun Singh Sandhu Department of Urology All India Institute of Medical SciencesJodhpurRajasthanIndia

Objective:The complexity of urethral strictures can predict outcomes following *** previously described urethral stricture score(U score)considered only stricture-related factors to grade the complexity of urethral strictures and to predict recurrence post urethroplasty,but not considered patient-related factors for the *** aimed to study the correlation of both of these factors to the outcomes of oral mucosal graft ***:We retrospectively reviewed data of 101 patients who underwent oral mucosal graft urethroplasty in our institute with a minimum follow-up of 6 *** patient characteristics and stricture-related parameters were *** U score was calculated for all patients which consisted of the length,location,number,and etiology of *** and multivariate Cox proportional hazard regression models were used to determine significant risk factors of ***:The mean follow-up of patients was 15 *** was seen in 28 patients and the mean time for detection of recurrence was 8 months of *** Charlson Comorbidity Index,history of previous intervention,length of strictures,location of strictures,number of strictures,history of smoking,and etiology were independent predictors of recurrence following *** on these parameters,we formulated the modified U score(MU score).The scores ranged from 0 to 6 and a score of>2 was found to be predictive of *** comparing receiver operating characteristic curves for both scores by the DeLong test,the MU score had larger area under the curve than the U ***:The MU scoring system is the first of its kind attempt taking into consideration both patient-and stricture-related factors to predict recurrence following oral mucosal graft urethroplasty.

关键词： Urethral stricture Urethral stricture score Recurrence Urethroplasty