bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of gas adsorbed on solid surface during gas breakdown in electron cyclotron resonance discharges
Authors: Fu S H , Ding Z F
Published: November 2021

The microwave breakdown power (P
wb) in an ECR plasma source was not merely determined by pressure (gas flow rate), but found to vary with the time interval between two successive breakdowns. The measured P
wb dropped rapidly from a high value at a short time interval to a low level at a long time interval. The obtained dependence of P
wb on pressure (gas flow rate) exhibited distinct features: the normal monotonicity and abnormal non-monotonicity at the short and long time intervals, respectively. The effective zone in the antenna’s surface, bombarded by hot electrons heated in the ECR layer, was validated by (1) masking the antenna with a film having a variable radius; (2) calculating the distribution of the vertical component of the microwave electric field with respect to the static magnetic field; and (3) imaging glows of transient breakdown discharges with a fast camera. The reduction in P
wb was mainly attributed to the enhanced emission of δ-electrons from the gas-adsorbed antenna under the bombardment of energetic electrons coming from the ECR layer. The correlation between the dynamic gas coverage and the emission coefficient of δ-electrons was established to understand the abnormal ECR breakdown features.
Unusual plasmonic responses in phosphorene with topological transition: the interplay of strain and doping
Authors: Zhou Y , Chen M N , Zhao M D , Tang F , Shao C Q , Dai M Y
Published: November 2021

In this paper, plasmonic responses of phosphorene in the presence of strain and doping have been systematically investigated. Based on density functional theory, permittivities include both the intraband and interband transitions of electrons have been calculated. Due to the modification of the band structure, significantly higher Drude plasma frequency has been observed along the zigzag direction, other than the armchair direction as in the usual case. The resulting unusual plasmonic responses change their anisotropy, both in the elliptic as well as the hyperbolic regimes. Based on our calculations, positive strain as large as 5% along the zigzag direction can even lead to so-called reversed hyperbolic plasmonic responses. The k-surfaces of the plasmonic modes in extended monolayer have been analytically solved, and it is found that actively switching the topology (between elliptic and hyperbolic regimes) of the plasmonic responses by changing the Fermi level is possible in phosphorene at certain frequencies. In the end, a simple model has been proposed to describe such plasmonic responses in the infrared and the parameters of the model have been listed in tables which can be used directly in calculating the permittivities. Our studies may extend the scope of existing investigations of phosphorene plasmons and lead to band engineering as a way to control plasmons in two-dimensional materials.
Quantum transport signatures of non-trivial topological edge states in a ring-shaped Su–Schrieffer–Heeger double-chain system
Authors: Ye Cheng-Zhi , Zhang Lan-Yun , Xue Hai-Bin
Published: November 2021

In the ring-shaped Su–Schrieffer–Heeger (SSH) double-chain, the quantum interference between the two different electron tunneling paths of the upper and lower chains has an important influence on the electron transport properties of non-trivial topological edge states. Here, we have studied the electron transport signatures of non-trivial topological edge states in a ring-shaped SSH double-chain system based on the wave-guide theory and transfer-matrix method. In the ring-shaped SSH double-chain with the upper chain being different from the lower one, it is demonstrated that the electron transmission probability displays the four and two resonance peaks associated with the non-trivial topological edge states in the weak and strong coupling regimes, respectively. Whereas in the case of the upper chain being the same as the lower one, the two transmission resonance peaks associated with the non-trivial topological edge states in the weak coupling regime are only found, and that in the strong coupling regime disappear that originated from the destructive interference between the two different electron tunneling paths of the upper and lower chains. Consequently, the variation of the number of transmission resonance peaks associated with the non-trivial topological edge states in the weak and strong coupling regimes suggests that an alternative scheme for detecting non-trivial topological edge states in the ring-shaped SSH double-chain system.
First-principles calculations of the hole-induced depassivation of SiO2/Si interface defects
Authors: Hong Zhuo-Cheng , Yao Pei , Liu Yang , Zuo Xu
Published: November 2021

The holes induced by ionizing radiation or carrier injection can depassivate saturated interface defects. The depassivation of these defects suggests that the deep levels associated with the defects are reactivated, affecting the performance of devices. This work simulates the depassivation reactions between holes and passivated amorphous-SiO2/Si interface defects (HPb + h → Pb + H+). The climbing image nudged elastic band method is used to calculate the reaction curves and the barriers. In addition, the atomic charges of the initial and final structures are analyzed by the Bader charge method. It is shown that more than one hole is trapped by the defects, which is implied by the reduction in the total number of valence electrons on the active atoms. The results indicate that the depassivation of the defects by the holes actually occurs in three steps. In the first step, a hole is captured by the passivated defect, resulting in the stretching of the Si–H bond. In the second step, the defect captures one more hole, which may contribute to the breaking of the Si–H bond. The H atom is released as a proton and the Si atom is three-coordinated and positively charged. In the third step, an electron is captured by the Si atom, and the Si atom becomes neutral. In this step, a Pb-type defect is reactivated.
Disruptive neoclassical tearing mode seeding in DIII-D with implications for ITER
Authors: La Haye R.J. , Chrystal C. , Strait E.J. , Callen J.D. , Hegna C.C. , Howell E.C. , Okabayashi M. , Wilcox R.S.
Published: November 2021

New studies identify the critical parameters and physics governing disruptive neoclassical tearing mode (NTM) onset. An m/n = 2/1 mode in DIII-D that begins to grow robustly after a seeding event (edge localized mode ELM or sawtooth precursor and crash) causes the mode rotation to drop close to the plasma’s E
r = 0 rest frame; this condition opens the stabilizing ion-polarization current ‘gate’ and destabilizes an otherwise marginally stable NTM. Our new experimental and theoretical insights and novel toroidal theory-based modeling are benchmarked and scalable to ITER and other future experiments. The nominal ITER rotation at q = 2 is found to be stabilizing (‘gate closed’) except for MHD-induced transients that could ‘open the gate’. Extrapolating from the DIII-D ITER baseline scenario (IBS) discharges, MHD transients are much more likely to destabilize problematic robustly growing 2/1 NTMs in ITER; this makes predictions of seeding and control of both ELMs and sawteeth imperative for more than just minimizing divertor pulsed-heat loading.
Studies on the role of ion mass and energy in the defect production in irradiation experiments in tungsten
Authors: Maya P.N. , Mukherjee S. , Sharma P. , Karki V. , Singh M. , Julie S. , Kikani P. , Satyaprasad A. , David C. , Pujari P.K. , Deshpande S.P.
Published: November 2021

Experimental investigations on the role of ion mass and the primary knock-on atoms (PKA) spectrum in the defect type, structure and defect production efficiency is presented in ion-irradiation experiments in tungsten using a combination of positron annihilation spectroscopy, transmission electron microscopy and secondary ion mass spectroscopy. Recrystallized tungsten foils were irradiated using low- (helium), medium- (boron) and high-mass (gold) ions of MeV energy for a comparable dpa and implantation range at room temperature. Depending on the ion mass and the PKA spectrum, distinctly different defect structures were observed at the atomistic as well as meso-scales. While no indication of dislocation lines was observed in 3 MeV helium irradiated samples, the boron and gold ions showed extensive dislocation line formation. The cluster shape depends on the PKA energy and the cluster density depends on the irradiation fluence. The depth profile analysis of the defects in the helium-irradiated samples showed extensive helium trapping throughout the implantation range. Significant sub-surface helium trapping is observed within 700 nm from the surface, indicating that they moved towards the surface from their mean implantation depth of 4500 nm. The study also shows a correlation between carbon and helium profiles in the samples.
International Symposium and International School for Young Scientists on “Physics, Engineering and Technologies for Biomedicine”
Authors: Kabashin A V , Klimentov S M , Timoshenko V Yu , Fronya A A
Published: November 2021

International Symposium and International School for Young Scientists on “Physics, Engineering and Technologies for Biomedicine” (PhysBioSymp) is an annually held event in National Research Nuclear University MEPhI (https://eng.mephi.ru/) (Moscow, Russia) since 2016. This symposium is conceived as the main conference of the Institute of Engineering Physics for Biomedicine (PhysBio, https://physbio.mephi.ru/), which is one of new strategic academic units founded in 2016 in the course of transformation of MEPhI from the technical to a global university in order to extend its portfolio toward life sciences, chemical and biomedical engineering. Following the chosen strategy, PhysBio aims at the advancement of its international reputation in biomedical sciences and technologies, as well as the integration of latest research achievements into the educational process in order to contribute to the solution of global problems, such as early diagnostics and efficient therapy of socially significant diseases, including cancer. Conceived as an essentially interdisciplinary institution, PhysBio is unique in combining powerful background of MEPhI in physics, mathematics, engineering, material sciences, nanotechnologies and expertise in new areas in chemistry and biology in order to develop breakthrough technologies for biomedical applications.

List of Committees are available in this pdf.
Strong light-matter coupling for optical switching through the fluorescence and FRET control
Authors: Nabiev I
Published: November 2021

Resonant interaction between excitonic transitions of molecules and localized electromagnetic field forms the hybrid polaritonic states. Tuneable microresonators may change the light-matter coupling strength and modulate them from weak to strong and ultra-strong coupling regimes. In this work we have realised strong coupling between the tuneable open-access cavity mode and the excitonic transitions in oligonucleotide-based molecular beacons with their terminus labelled with a pair of organic dye molecules demonstrating an efficient donor-to-acceptor Förster resonance energy transfer (FRET). We show that the predominant strong coupling of the cavity photon to the exciton transition in the donor dye molecule can lead to such a large an energy shift that the energy transfer from the acceptor exciton reservoir to the mainly donor lower polaritonic state can be achieved, thus yielding the chromophores’ donor–acceptor role reversal or “carnival effect”. The data show the possibility for confined electromagnetic fields to control and mediate polariton-assisted remote energy transfer. Obtained results open the avenues to quantum optical switching and other applications.
Comparison of pharmacokinetics and biodistribution of laser-synthesized plasmonic Au and TiN nanoparticles
Authors: Popov Anton A , Zelepukin Ivan V , Tikhonowski Gleb V , Popova-Kuznecova Elena A , Tselikov Gleb I , Al-Kattan Ahmed , Bailly Anne-Laure , Correard Florian , Braguer Diane , Esteve Marie-Anne , Klimentov Sergey M , Deyev Sergey M , Kabashin Andrei V
Published: November 2021

Plasmonic nanostructures offer wide range of diagnostic and therapeutic functionalities for biomedical applications. Gold nanoparticles (Au NPs) present one of the most explored nanomaterial in this field, while titanium nitride nanoparticles (TiN NPs) is a new promising nanomaterial with superior plasmonic properties for biomedicine. However conventional chemical techniques for the synthesis of these nanomaterials cannot always match stringent requirements for toxicity levels and surface conditioning. Laser-synthesized Au and TiN NPs offer exceptional purity (no contamination by by-products or ligands) and unusual surface chemistry. Therefore, these NPs present a viable alternative to chemically synthesized counterparts. This work presents comparative analysis of pharmacokinetics and biodistribution of laser-synthesized 20 nm Au and TiN NPs under intravenous administration in mice model. Our data show that Au NPs and bare TiN NPs are rapidly eliminated from the blood circulation and accumulate preferentially in liver and spleen, while coating of TiN NPs by hydrophilic polymer polyethylene glycol (PEG) significantly prolongates blood circulation time and improves delivery of the NPs to tumor. We finally discuss potential applications of laser synthesized Au NPs in SERS, SEIRA and electrocatalysis, while TiN nanoparticles are considered as promising agents for photothermal therapy and photoacoustic imaging.
MIL-53 (Al) metal-organic frameworks as potential drug carriers
Authors: Griaznova O Yu , Zelepukin I V , Tikhonowski G V , Kolokolnikov V N , Deyev S M
Published: November 2021

One of the challenges of the medicine is to improve the chemical stability of drugs and to prevent their premature biodegradation before reaching the therapeutic target. Various nanoparticles were used to solve this problem, but low drug loading efficiency limited their biomedical applications. Metal organic frameworks are promising candidates for drug delivery since they have extremely high surface area and regular porosity. In this study, we prepared high-crystalline MIL-53 frameworks based on aluminium and 2-aminoterephtalic acid by microwave-assisted synthesis and evaluated their properties as drug carriers. Drug loading of chemotherapeutic and diagnostic molecules of different nature riches value of 34% by particle weight, significantly higher than those of other reported solid nanoparticles. Therefore, our results make MIL-53 (Al) frameworks promising candidate for drug delivery.
Small-angle X-ray (SAXS) and Raman spectroscopy studies of biot-CMG(2)-DOPE quasicrystalline phases
Authors: Maslennikov A M , Zalygin A V , Shtykova E V , Bovin N V , Oleinikov V A
Published: November 2021

Neoglycolipids due to their amphiphilic properties exhibit self-assembly in aqueous phases. In high concentrations the liquid crystalline or gel phases may form. So-called soft-material are a subject of interest of many scientists especially as biosensors and wound healing materials. In this study we examine the structure of a quasicrystalline phase of biot-CMG(2)-DOPE obtained at the concentration of 150 mg/ml (13wt.%) in PBS. The structural data such as interplanar spacing, order parameter and long-range order were obtained by SAXS, while the changes in chemical structure were studied by Raman spectroscopy. It was also in our interest to examine a correlation between the ionic strength and the self-assembly, so we also studied a similar quasicrystalline phase of the same compound but in a buffer containing CaCl2 at the concentration of 4wt.%. According to SAXS data, FSL-biotin construct formed a complex ordered phase consisting of overlapping latices of different kind. The addition of CaCl2 into PBS resulted in obtaining a more structured system demonstrating cubic-like crystal lattice. Change in peak intensities on Raman spectrums of -C-H- and -C-C- bonds vibrations explained the change in phase properties.
Effect of electrolyte conductivity and local electric field inhomogeneity on heating of an aqueous suspension of solid-state nanoparticles
Authors: Grigoriev A A , Zavestovskaya I N , Kargina Yu V , Kharin A Yu , Kanavin A P , Timoshenko V Yu
Published: November 2021

This work theoretically investigates the process of heat release in an electrolyte near a solid-state nanoparticle when exposed to an external radio-frequency electromagnetic field. The effect on the heat release of the effect of a change in the electrical conductivity of the electrolyte near the nanoparticle due to the redistribution of the ion concentration and the inhomogeneity of the electric field caused by the difference in the dielectric constants of the electrolyte and the nanoparticle is taken into account. The proposed model can be useful for choosing the optimal parameters of nanoparticles and radio frequency radiation when used in biomedicine for tumor hyperthermia.
Fluorescence diagnostics and photodynamic therapy of squamous cell carcinoma of the lateral surface of the tongue using the photosensitizer chlorin e6 by spectroscopic video fluorescence methods
Authors: Kulichenko A , Farrakhova D S , Yakovlev D V , Maklygina Yu S , Shiryaev A A , Loschenov V B
Published: November 2021

This paper presents the results of using intraoperative fluorescence diagnostics (FD) with the endoscopic video system to increase the efficiency of photodynamic therapy (PDT). The molecular form of chlorin e6 was used as a photosensitizer (PS). All patients received an intravenous administration drug based on chlorin e6 at the concentration of 1 mg/kg. Diagnostics and therapy were carried out in 4 patients diagnosed by malignant neoplasms of the lateral surface of the tongue. Determination of the boundaries by changing the signal of the fluorescence intensity of the tumor was carried out before PDT and after PDT. The efficiency of PDT was assessed by the fluorescent signal of the tumor decreasing when compared with non-pathological normal tissue. The FD method allows to determine accurately the actual size of the tumor and its borders. All patients underwent PDT influenced by the therapeutic laser with a generation wavelength of 660 nm. It is shown that the using of fluorescence diagnostics improves the quality of the photodynamic therapy, since it is possible to assess the photobleaching of the drug during the operation.
Laser-based inactivation of pathogenic microorganisms
Authors: Shelygina S N , Kompanets V O , Saraeva I N , Tolordava E R , Kudryashov S I , Rupasov A E , Baitsaeva O I , Zayarniy D A , Savinov M S , Chekalin S V , Ionin A A
Published: November 2021

In the context of studying the possibility of inactivation of pathogenic microorganisms, the dynamic transmission spectra of femtosecond laser radiation in the mid-IR range by bacteria of the Pseudomonaus aeruginosa culture planted on a silicon substrate were investigated. Irradiation revealed a blue shift in the characteristic absorption bands of bacteria, indicating the breaking of hydrogen bonds responsible for the formation of the secondary and tertiary structure of the proteins.
Optical biopsy: fundamentals and applications in neurosurgery
Authors: Savelieva T A , Romanishkin I D , Maklygina Yu S , Grachev P V , Kalyagina N A , Borodkin A V , Orlov A V , Tsarukaev B A , Aristov A A , Kosyrkova A V , Goryajnov S A , Shugaj S V , Shishkina L V , Potapov A A , Loschenov V B
Published: November 2021

Currently, there is a significant increase in the incidence of cancer of the central nervous system. Determination of the boundaries of intracerebral and intramedullary tumors is especially difficult. The urgency of the problem of determining the boundaries of astrocytic tumors is due to the peculiarities of their growth along myelinated nerve fibers and vessels, leading to the infiltration of healthy white matter by tumor cells, which affects the high frequency of postoperative relapses. The complexity of surgery for intramedullary tumors of the spinal cord is that the tumor does not always have a clear border and the risk of injury is high due to the smaller size of the operated area compared to the brain. Reliable information regarding the volume of the resected tumor should be obtained by intraoperative imaging. The solution to this problem is implemented mainly in three directions: the use of intraoperative computed tomography, magnetic resonance imaging and ultrasound scanning, and various combinations of these methods. Unfortunately, all these methods of intraoperative diagnostics do not allow real-time examination of tissues in an operating wound and/or do not provide a simultaneous analysis of both structural and metabolic changes. The limitations of intraoperative navigation methods in neurosurgery have led to the relevance of the development of an accurate spectroscopic method for in vivo determination of the content of specific metabolic markers and structural changes accompanying the development of the tumor process in the nervous tissue. Various approaches to intraoperative navigation based on optical spectroscopy are called optical biopsy. In this article, we present the methods and tools developed in recent years for spectroscopic guidance in neurooncology. First of all, this, of course, concerns the analysis of spectral dependences recorded before, during and after tumor removal. We have used such modalities of optical spectroscopy as fluorescence, diffuse reflectance spectroscopy and spontaneous Raman scattering. An equally important issue on the way to increasing the efficiency of tumor resection is the development of new instrumentation; therefore, we have developed a number of new devices, which are a combination of well-known neurosurgical instruments and laser and fiber-optic technologies. Last but not least is the issue of rapid classification of the studied tissues based on the recorded signals, which was solved by us using machine learning methods.
Application of atomic force microscopy in biology and medicine
Authors: Nikitaev V G , Pronichev A N , Markov T K , Esaulov N
Published: November 2021

This article presents the main areas of application of atomic force microscopy in biology and medicine, describes the principle of an atomic force microscope and the main modes of its operation. The works and results of the leading laboratories in the stated topic are considered. There are a number of proposals for generalizing the considered results into a unified knowledge base on diseases and the general state of health of the human body.
Brain–computer interface technologies for monitoring and control of bionic systems
Authors: Berestov R M , Bobkov E A , Belov V S , Nevedin A V
Published: November 2021

At the moment, neurocomputer interfaces (BCI) make it possible to implement on their basis devices for diagnosing a physical condition, implementing control systems for bionic prostheses, information input means such as neuro chat and character set systems based on brain potentials. At the moment, the main technology for obtaining brain activity for neurointerfaces is the electroencephalogram (EEG). There are promising technologies that will make it possible to achieve new results in the field of neurointerfaces. These technologies are functional near infrared spectroscopy (fNIRS) and magnetoencephalography (MEG).
Integrated information and measurement system for the diagnosis of acute leukemia and minimal residual disease based on computer microscopy, flow laser cytofluorimetry and artificial intelligence
Authors: Nikitayev V G , Pronichev A N , Tupitsin N N , Selchuk V Yu , Dmitrieva V V , Palladina A D , Polyakov E V , Liberis K A , Tsyplyak V I
Published: November 2021

The article considers a new integrated information and measurement system for the diagnosis of acute leukemia and minimal residual disease based on computer microscopy and flow laser cytometry. The system is based on combining the results of computer microscopy in the analysis of bone marrow preparations and the results of flow laser cytofluorimetry. A special feature of the system is the use of artificial intelligence technologies in the recognition of images of bone marrow cells in the computer microscopy subsystem. The work was the result of joint work of the Department of Computer Medical Systems of the National Research Nuclear University "MEPhI" and the Laboratory of Hematopoietic Immunology of the National Medical Research Center of Oncology named after N. N. Blokhin.
Biodistribution of phenylalanine labeled with gallium-68
Authors: Tishchenko V K , Petriev V M , Stepchenkova E D
Published: November 2021

Positron emission tomography (PET) is modern high sensitivity method of various tumor imaging. The synthesis of new radiopharmaceuticals based on amino acids and positron emitting radionuclide 68Ga for PET imaging is of great interest. This work is devoted to study the biodistribution of a new agent based on amino acid phenylalanine and 68Ga (68Ga-phenylalanine) in Wistar rats with cholangioma RS-1 after intravenous administration. A comparative investigation of 68Ga-phenylalanine and 68GaCl3 biodistribution was also carried out. It was shown that the highest uptake of 68Ga-phenylalanine was observed in blood, liver, femur and tumor. Tumor uptake of 68Ga-phenylalanine increased 3.5 times from 0.20 ± 0.03 % ID/g to 0.70 ± 0.10 % ID/g, whereas uptake of 68GaCl3 decreased from 0.34 ± 0.07 % ID/g to 0.13 ± 0.04 % ID/g within 3 h. Blood uptake of 68Ga-phenylalanine reached 2.98 ± 0.31 % ID/g. In other organs and tissues the uptake of 68Ga-phenylalanine didn’t exceed 1 % ID/g. Kidneys and femur uptake of 68Ga-phenylalanine was lower as compared with 68GaCl3, but in other organs the uptake of 68Ga-phenylalanine was similar or slightly higher when compared with 68GaCl3.
The influence of temperature on biodistribution of N,N,N’,N’- ethylenediaminetetrakis(methylene phosphonic) acid labeled with gallium-68
Authors: Tishchenko V K , Petriev V M , Stepchenkova E D , Shegai P V , Ivanov S A , Kaprin A D
Published: November 2021

Bone metastases are serious complication in the progression of various types of cancer. It determines the requirement of modern nuclear diagnostic tools, including positron emission tomography (PET). In this study the biodistribution of EDTMP labeled with gallium-68 (68Ga-EDTMP) prepared at different temperature (20, 50, and 95 °C) was investigated. All experimental studies were performed in healthy intact Wistar rats by measuring the radioactivity in organs and tissues with gamma counter. All 68Ga-EDTMP formulations accumulated predominantly in bones. Only in tibia the uptake of 68Ga-EDTMP prepared at 95 °C was higher (p < 0.05) than 68Ga-EDTMP prepared at 20 °C, but in other bones there weren’t any statistical differences in uptake of 68Ga-EDTMP formulations. The amounts of 68Ga-EDTMP formulations in soft organs and tissues were lower when compared with bones. In conclusion, a temperature of reaction mixture had an influence on the biodistribution of 68Ga-EDTMP in bones.
Classification of bone marrow cells in the diagnosis of acute lymphoblastic leukemia
Authors: Nikitayev V G , Pronichev A N , Tupitsin N N , Selchuk V Yu , Dmitrieva V V , Palladina A D , Polyakov E V , Liberis K A , Dzhokich M , Solomatin M A , Nosova E M
Published: November 2021

The paper presents approaches to automated classification of bone marrow cells in the diagnosis of acute lymphoblastic leukemia and minimal residual disease using image recognition procedures. The classification methods that show the best accuracy in the recognition of eight types of bone marrow cells were experimentally determined. Recommendations for their use are given.
Learning electrical circuits for the development of critical thinking
Authors: Escobar Moreno F , Ramírez Díaz M H
Published: November 2021

This article presents an articulated proposal of two pedagogical approaches to favor the development of critical thinking from a physics topic. The purpose is to design a didactic sequence for the subject of electrical circuits, using two articulated pedagogical approaches so that students from a school of engineering in Mexico must solve an engineering problem linked to a relevant topic of physics, such as the characteristics of electrical circuits, the problem must be solved methodologically and systematically. The inquiry approach is quantitative, with a quasi-experimental design, a validated instrument is used for data collection. Subsequently, the hypothesis test for differences between means is applied and the results are analyzed. Thus, it is found that the development of critical thinking is incipient; however, the assessment of physics learning products reveals relevant findings such as the promotion of creativity. Likewise, the problem presented to the students allows them to contextualize their learning and recognize the relevance and application of the characteristics of electrical circuits. This inquiry confirms that the development of critical thinking through physics improves the comprehensive training of engineers. Therefore, according to the results, there is empirical evidence that both articulated methodologies can gradually favor the development of critical thinking; In addition, the methodological and contextualized learning of physics through the subject of electrical circuits is applied to a branch of engineering.
Gains in active learning of physics: a measurement applying the test of understanding graphs of kinematics
Authors: Hernández C A , Prada Núñez R , Gamboa A A
Published: November 2021

To teach the subject of physics in the classroom it is required that the teacher has and plans to carry a didactic strategy with him. Within this context is the methodology called Active physics learning, which is a strategy within the classroom and in the laboratory, as it allows the student to learn physics without depending on a textbook or the teacher who guides the course. The test of understanding graphs of kinematics assesses students’ comprehension of kinematics. We report the application of an active learning experience for the conceptual learning of kinematics of students taking the subject of physics in an elementary and middle school. The study is quasi-experimental with a single group of 29 students using a pretest-intervention-posttest design. With the results of the pretest and posttest the Hake learning gain index was estimated and showed evidence of the implementation of active learning in the conceptual evolution of students in kinematic concepts and their representation by means of graphs. This becomes a precedent for the improvement of pedagogical practice in favor of quality education.
Digital portfolio: a tool for learning physics
Authors: Espinel-Rubio G A , Hernández-Suarez C A , Paz-Montes L S
Published: November 2021

The digital portfolio is a student-student, student-teacher interaction tool where formative assessment plays an important role in the learning of physics, with which the progress of students is monitored, the entire training process is evaluated and supported of the student, according to the planning and contents of the physics course. Therefore, this article describes the use of the digital portfolio as a tool for learning in students of a teacher training program in natural sciences and environmental education at a public university in Colombia. It is a quantitative study with a non-experimental design. The research subjects were students taking the subject of basic physics. The results indicate that students perceive the portfolio as a tool that allows monitoring and reflection of their learning and favor the integration of what they have learned, which supports the use of this tool, in accordance with the results of evaluation of the students’ formative process. However, the use of the portfolio requires a continuous process of change and innovation, monitoring and permanent feedback between the teacher and the students.
Regularization algorithm and its implementation in general systems theory and its implications in physics
Authors: Mesa F , Devia D M , Correa G
Published: November 2021

In recent years a new physics known as complexity has emerged, whose fundamental structure is based on the general theory of systems or the so-called mathematical biology. There, problems arise with a large number of variables on which decisions must be made, and it is important to have selection techniques that are robust and efficient, In this research work, a couple of techniques are presented that will serve the aforementioned purpose; these are: the Lasso regularized linear regression technique and the Ridge regression technique, the latter with the slight difference in the penalty, since it makes use of a different rule than the Euclidean one, which implies very different consequences. One of these techniques was applied in a clinical problem and corresponds to the study of patients with diabetes. With this objective, the algorithm of descent of coordinates was implemented for the type of regularization loop and the analytical solution of regression of ridges. In addition, Kernels was used for the implementation of the regularized vector machine. The above algorithms were compared with the Ridge regularization and the Euclidean regularized vector machine. These types of techniques are common in physics, and it is vitally important to be able to implement other types of rules for a problem in which the choice of them can be simplified.
Mathematical and physical techniques of modeling and simulation of pattern recognition in the stock market
Authors: Montoya O D , Narváez D D , Ramárez Vanegas C A
Published: November 2021

The following article presents the analysis through mathematical and physical techniques of large databases, which are very common today, due to the large number of variables (especially in the information and physics industry) and the amount of information that results from a process, therefore an analysis is necessary that allows the Decision in a responsible manner, looking for scientific criteria that support said decisions, in our case a database of the forex system will be taken. Initially, a study and calculation of different measurements between the samples and their characteristics will be carried out to make a good prediction of the data and their behavior using different classification methods inspired by basic sciences. Below is an explanation of the techniques based on the analysis of data components and the correlations that exist between the variables, which is a technique widely used in physical processes to determine the correlations between variables.
Modeling of the physical phenomenon of heat generation by using partial differential equations
Authors: Cadena Morales J J , López Castro C A , Rojas Molano H F
Published: November 2021

The equations of mathematical physics are a natural environment for modeling physical phenomena, an example of the above is evidenced by the heat equation in relation to its use in a variety of applications; directly related to the equations of mathematical physics are the solution methods that are used to construct the predictive models. This paper describes step by step the analytical method of separation of variables to perform a complete description of the heat conduction phenomenon in the presence of a heat generation source. The investigation by using mathematical arguments allowed to calculate the temperature function as the addition of a Fourier series and a function which represents the steady state; by performing a computational simulation, it was possible to demonstrate the accuracy of the results achieved.
Validation of the modified Témez rational model in the watersheds of Norte de Santander, Colombia
Authors: Cely-Calixto N J , Carrillo Soto G A , Becerra-Moreno D
Published: November 2021

Physics includes the study and investigation of the phases that make up the hydrological cycle, including the estimation of flow rates in river basins, most of which are not instrumented, i.e., they lack historical records of circulating flows. For this situation, the application of hydrological models can allow flow estimates to be made. In the Department of Norte de Santander, Colombia, some watersheds do not have instrumentation for flow measurement or hydrological modeling methodologies appropriate to the site. Therefore, methods such as the modified rational model of Teméz are used, even without knowing the relevance of its applicability to the site conditions. Consequently, for the present research, the Teméz model was validated in watersheds of the Norte de Santander Department to estimate the values of extreme flows with a return period of 100 years. In this sense, 11 watersheds were selected, which contained historical rainfall data greater than 20 years and a drainage network of fewer than 1000 Km2. It was found that the Teméz model overestimates the real flows of the 11 hydrological basins, where the climatological parameters used in the application of the Fhrüling factor and its statistical verification using multivariate regression did not achieve an acceptable correlation.
Teaching the concept of the uniform plane wave from mathematical modeling
Authors: Soto-Vergel A J , Medina-Delgado B , Palacios-Alvarado W
Published: November 2021

The discovery of electromagnetic waves enabled us to understand electricity, magnetism, and optics under the same field; therefore, it is important for electronic and related engineers to understand the concept of the uniform plane wave, which represents the simplest case of an electromagnetic wave propagating through a medium. However, this concept is taught with a theoretical approach, shows a need for a methodological change towards experimentation to mitigate poor learning in students causing a high failure rate in electromagnetism courses. In this context, this work presents a methodological alternative for teaching the concept of the uniform plane wave, combining the CUVIMA model with the didactics of mathematical modelling, to link experimentation and provide cognitive support to the conceptualization of the physical phenomenon. For it, a single-group design is implemented, with pre-test and post-test, to know about previous ideas and identify the conceptual change achieved for the students. When applying the Student’s t-test at a significance level of 5%, a significant difference is evident between the means of the study groups. It is concluded that there is a favorable and representative conceptual change in the students, with respect to the understanding of the physical phenomenon represented by the concept of the uniform plane wave.
Characterization of milkweed-seed gust response
Authors: Galler Joshua N , Rival David E
Published: November 2021

Inspired by the reproductive success of plant species that employ bristled seeds for wind-borne dispersal, this study investigates the gust response of milkweed seeds, selected for their near-spherical shape. Gust-response experiments are performed to determine whether these porous bodies offer unique aerodynamic properties. Optical motion-tracking and particle image velocimetry (PIV) are used to characterize the dynamics of milkweed seed samples as they freely respond to a flow perturbation produced in an unsteady, gust wind tunnel. The observed seed acceleration ratio was found to agree with that of similar-sized soap bubbles as well as theoretical predictions, suggesting that aerodynamic performance does not degrade with porosity. Observations of high-velocity and high-vorticity fluid deflected around the body, obtained via time-resolved PIV measurements, suggest that there is minimal flow through the porous sphere. Therefore, despite the seed’s porosity, the formation of a region of fluid shear, accompanied by vorticity roll-up around the body and in its wake, is not suppressed, as would normally be expected for porous bodies. Thus, the seeds achieve instantaneous drag exceeding that of a solid sphere (e.g. bubble) over the first eight convective times of the perturbation. Therefore, while the steady-state drag produced by porous bodies is typically lower than that of a solid counterpart, an enhanced drag response is generated during the initial flow acceleration period.
Greening-induced increase in evapotranspiration over Eurasia offset by CO2-induced vegetational stomatal closure
Authors: Zhang Xuanze , Zhang Yongqiang , Ma Ning , Kong Dongdong , Tian Jing , Shao Xingmin , Tang Qiuhong
Published: November 2021

Evapotranspiration (ET), as a key exchanging component of the land energy, water and carbon cycles, is expected to increase in response to greening land under a warming climate. However, the relative importance of major drivers (e.g. leaf area index (LAI), climate forcing, atmospheric CO2, etc) to long-term ET change remain largely unclear. Focusing on the Eurasia which experienced the strong vegetational greening, we aim to estimate the long-term ET trend and its drivers’ relative contributions by applying a remote sensing-based water-carbon coupling model— Penman–Monteith–Leuning version 2 (PML-V2) driven by observational climate forcing and CO2 records, and satellite-based LAI, albedo and emissivity. The PML-V2 estimated an increasing ET trend (6.20 ± 1.13 mm year−1 decade−1, p < 0.01) over Eurasia during 1982–2014, which is close to the ensemble mean (6.51 ± 3.10 mm year−1 decade−1) from other three ET products (GLEAMv3.3a, ERA5 and CRv1.0). The PML-based ET overall agrees well with water-balance derived ET in detecting the trend directions. We find that the Eurasian ET increasing trend was mostly from vegetated regions over central and eastern Europe, Indian and southeast China where ET trends were larger than 20 mm year−1 decade−1. Modeling sensitivity experiments indicate that the Eurasian ET trend was mainly dominated by positive contributions from climate forcing change (40%) and increased LAI (22%), but largely offset by a negative contribution of increased CO2 (26%). Our results highlight the importance of the suppression effect of increasing CO2-induced stomatal closure on transpiration. This effect was rarely considered in diagnostic ET products but plays a key role to ensure that the long-term ET trend should not be overestimated by only accounting for greening-induced increases in transpiration and rainfall interception.
The variability of volatile organic compounds in the indoor air of clinical environments
Authors: Salman Dahlia , Ibrahim Wadah , Kanabar Amisha , Joyce Abigail , Zhao Bo , Singapuri Amisha , Wilde Michael , Cordell Rebecca L , McNally Teresa , Ruszkiewicz Dorota , Hadjithekli Andria , Free Robert , Greening Neil , Gaillard Erol A , Beardsmore Caroline , Monks Paul , Brightling Chris , Siddiqui Salman , Thomas C L Paul
Published: November 2021

The development of clinical breath-analysis is confounded by the variability of background volatile organic compounds (VOCs). Reliable interpretation of clinical breath-analysis at individual, and cohort levels requires characterisation of clinical-VOC levels and exposures. Active-sampling with thermal-desorption/gas chromatography-mass spectrometry recorded and evaluated VOC concentrations in 245 samples of indoor air from three sites in a large National Health Service (NHS) provider trust in the UK over 27 months. Data deconvolution, alignment and clustering isolated 7344 features attributable to VOC and described the variability (composition and concentration) of respirable clinical VOC. 328 VOC were observed in more than 5% of the samples and 68 VOC appeared in more than 30% of samples. Common VOC were associated with exogenous and endogenous sources and 17 VOC were identified as seasonal differentiators. The presence of metabolites from the anaesthetic sevoflurane, and putative-disease biomarkers in room air, indicated that exhaled VOC were a source of background-pollution in clinical breath-testing activity. With the exception of solvents, and waxes associated with personal protective equipment (PPE), exhaled VOC concentrations above 3 µg m−3 are unlikely to arise from room air contamination, and in the absence of extensive survey-data, this level could be applied as a threshold for inclusion in studies, removing a potential environmental confounding-factor in developing breath-based diagnostics.
Analysis of the Mw 6.5 Ambon Earthquake (September 26, 2019) based on the aftershocks hypocenter relocation
Authors: Supendi P , Nugraha A D , Widiyantoro S , Abdullah C I , Daryono  , Karnawati D , Palgunadi K H , Rohadi S , Gunawan M T , Rosalia S
Published: November 2021

On September 26, 2019, an earthquake (Mw 6.5) occurred in the northern part of Ambon Island, Molucca, East Indonesia. The National Authority show this earthquake caused infrastructures damage and 28 fatalities. Up to October 31, 2019, the Indonesian Agency for Meteorology, Climatology, and Geophysics (BMKG) seismic network had recorded 479 aftershock events. We have relocated 463 out of the 479 aftershocks using the double-difference method. Our results show that some improvements in the hypocenter locations, where the focal depths of initial earthquakes fixed at 10 km have been updated to ~9.8 km depth on average. There are two aftershock clusters in a North-South direction of ~35 km length between Ambon Island and Haruku Island and in a West-East direction of ~30 km length in the Ambon Island, each with a width of ~8 km.
3D Seismic Waves Velocity Structure of West Sumatera Seismic Waves Using Earthquake Data from January 2010-December 2017
Authors: Wulandari Rizki , Yudistira Tedi , Fattah Erlangga Ibrahim , Aulia Atin Nur , Wibowo Adhi
Published: November 2021

This study analyses the P wave velocity (Vp) and Vp/Vs based on 3D seismic tomography in West Sumatra. Seismic tomography is a method of reconstructing the image of the subsurface structure of the earth using travel time data. This research uses secondary data obtained from the Incorporated Research Institutions for Seismology (IRIS) from January 2010 to December 2017. The data obtained were 472 earthquake events and 21 seismic stations that recorded the earthquake events. This research consists of are the hypocenter relocation, which will simultaneously renew the 1D velocity model using VELEST software, and tomographic inversion using SIMULPS12 software. The minimum anomaly of Vp/Vs value is around 1.39, while the maximum anomaly Vp/Vs value is around 2.05. The Vp distribution results have low and high Vp/Vs values around Sumatra Fault Zone and Mentawai Fault Zone. Anomaly results from the tomogram of these areas have an association with saturated pressure sedimentary areas and the presence of fractures which will further contribute to earthquake events.
The M 6.5 Ambon earthquake 26 September 2019: the source mechanism and the aftershock sequence characteristics
Authors: Rohadi S. , Perdana Y.H. , Herayndoko N. , Sunardi B. , Prakoso T. A. , Suliyanti  , Sunardi  , Florida N. , Edison Robert , Karnawati D.
Published: November 2021

The area of Ambon, Maluku is located in the subduction zone in bands where the Australian plate meets the Eurasian plate, thus causing tectonic activities. The Ambon earthquake on 26th September 2019 with 6.5 Magnitude, while the Epicentral coordinates of the earthquake were determined as 3,53° S and 128,39° E and a focal depth of 10 km, according to the Agency for Meteorology Climatology and Geophysics, Indonesia. This earthquake was strongly felt at the biggest shock was felt with intensity VI-VII as unified in Ambon City, while several other areas are reported to have experienced small shaking, such as Intensity V in Masohi, and Intensity IV in Namlea and Namrole. We used a dataset of 24 waveforms of seven sensors, we determine a tabular solution, which have a large moment of 0.4573 x 1019 N-m, the depth is 6 km by minimizing the inversion residual. The method resulting strike and rake fault, with strike: 341.8°; dip; 81.5°; rake: 158.4°, and second nodal plane strike: 75.1°; dip; 68.6°; rake: 9.14°. The mechanisms were compared with those from other agency in agreement. The time decay intervals between mainshocks and significant aftershocks follow Mogi and Utsu’s Law but with a relatively faster rate of decay than that of aftershocks in general.