Induction Phenomena Research Articles

Non-Selective Magnetoelectric Thermal Radiation Receiver Based on Cadmium Antimonide

The ways of increasing the sensitivity of a non-selective thermal radiation receiver based on cadmium antimony using the phenomenon of electromagnetic induction are considered and investiga­ted. It has been shown that the application of ani­sotropic NdFeB anisotropic magnet increases the volt-watt sensitivity of the thermal radiation recei­ver by 30 %. When a more powerful magnet is used, an additional increase in sensitivity is observed, but not in proportion to the magnitude of the additio­nal magnetic induction. The dynamic range of the created thermal radiation receiver, which is from 10 to 200000 W/m-2, is investigated.

Faraday induction from point-charge fields

Interpreting Faraday's law of induction has been a challenge for students, because this law involves abstract and sophisticated concepts such as the magnetic flux, given by a surface integral, and the electromotive force, given by a line integral. Besides that, Faraday's law is not clear with respect to the sources of the different fields of force, electric and magnetic, involved simultaneously in the phenomenon of induction. We discuss Faraday's electromagnetic induction through the magnetic and electric fields of point-charges in a quasistatic regime. From this perspective, we show that the results of Faraday's experiments that led to the discovery of electromagnetic induction can be understood in terms of the electric acceleration and velocity fields of point charges.

Comparative Transcriptomic Analysis Reveals Molecular Profiles of Central Nervous System in Maternal Diapause Induction of Locusta migratoria.

Egg diapause in Locusta migratoria L. (Orthoptera: Acridoidea) is believed to be influenced by maternal photoperiod. However, the molecular mechanism regulating the phenomenon of maternal diapause induction is unclear. Here we performed transcriptomic analyses from the central nervous system (CNS) of migratory locusts under long and short photoperiods to identify differentially expressed genes (DEGs) related to diapause induction. There were total of 165750 unigenes from 569491 transcripts, and 610 DEGs were obtained in S_CNS (CNS of short photoperiod treated locusts) vs. L_CNS (CNS of long photoperiod treated locusts). Of these, 360 were up-regulated, 250 were down-regulated, and 84 DEGs were found to be related to FOXO signaling pathways, including citrate cycle/TCA cycle, glycolysis/ gluconeogenesis, oxidative phosphorylation, and PI3K-Akt. The qRT-PCR validation of mRNA expression of 12 randomly selected DEGs showed consistency with transcriptome analysis. Furthermore, the takeout gene thought to be involved in circadian rhythm was cloned and used for RNAi to observe its function in maternal diapause induction. We found that the mRNA level of Lm-takeout was significantly lower in dstakeout treatments as compared to the control under both long and short photoperiods. Similarly, the offspring diapause rate was significantly higher in dstakeout treatment as compared to the control only in short photoperiod. This shows that the Lm-takeout gene might be involved in the inhibition of maternal diapause induction of L. migratoria under short photoperiods. The present study provides extensive data of the CNS transcriptome and particular insights into the molecular mechanisms of maternal effects on egg diapause of L. migratoria. As well for the future, the researchers can explore other factors and genes that may promote diapause in insect species.

Teaching and Learning about Magnetic field and Electromagnetic Induction Phenomena integrated Science, Technology, Engineering and Mathematics (STEM) Education in Vietnamese high schools

This work presents the study on teaching and learning about magnetic and electromagnetic induction phenomena integrated science, technology, engineering and mathematics (STEM) education in Vietnamese high schools for addressing issues of relevance and epistemic practice. We have explored STEM education with the creative and experiential activity in magnetic and electromagnetic induction phenomena. The STEM experiments and technical toys about magnetic and electromagnetic induction phenomena have been designed to be applied for active learning for students. The integration of STEM education will increase motivation and achievement in physics subjects and enhance capacity to improve student learning.

E. E. Just's broad, yet hidden, influence on modern cell and developmental biology.

This year, 2019, marks the centennial of embryologist E. E. Just's discovery of what is known as the fast block to polyspermy. Just's observation of the subtle changes that occur at the egg's surface during fertilization (and in experimental parthenogenesis) led him to postulate that the egg, and indeed every cell, possesses a property he called independent irritability, which represents the cell's ability to respond in a physiologically-relevant way to a variety of signals or triggers. In this paper, I argue that Just's concept of independent irritability informed his contemporary Johannes Holtfreter as Holtfreter attempted to explain the phenomena of embryonic induction and competence and that Holtfreter, in turn, influenced Marc Kirschner and John Gerhart in their formulation of the theory of facilitated variation. Just's influence is especially evident in Gerhart and Kirschner's presentations of what they call weak linkage-a property of living systems that allows core processes and components to be mixed and matched in different ways to generate novel traits. Unfortunately, the connection between Holtfreter's work and Just's has remained hidden. This paper gives examples of phenomena that exhibit weak linkage, and it lays out the case that Just's concept of independent irritability, through Holtfreter, Gerhart, and Kirschner, has broadly infiltrated modern cell and developmental biology.

Research of electrostatic field measurement sensors

Due to the discharge of static electricity, the force of static electricity and the phenomenon of electrostatic induction, it poses a major safety hazard for on-site operations personnel and equipment, resulting in significant losses and hazards. When people work on site, they can't intuitively know whether there is static electricity and quantify the static charge on the device. Therefore, this article describes the design principle of the sensor in the electrostatic field measurement in detail. In this paper, theoretical analysis and simulation analysis are carried out for two different working modes of variable-area and variable-pitch sensors. The experimental results verify the measurement principle of the vibration capacitor sensor, and the MEMS electric field sensor is also described in detail. This paper analyzes and summarizes the characteristics of existing electrostatic field measurement sensors at home and abroad in order to select reference for electrostatic field measurement sensor design and actual scene measurement operations.

Inducible resistance to clindamycin in methicillin-resistant Staphylococcus aureus isolated from Paraguayan children

The double disc diffusion method is an alternative diagnostic that allows the identification of Staphylococcus aureus isolates apparently susceptible to clindamycin but that may develop resistance due to an induction phenomena, mainly asociated to the increase in resistance to methicillin, thus increasing the possibility of failure in the treatment. To determine the frequency of induced clindamycin resistance in methicillin-resistant S. aureus (MRSA) isolated from Paraguayan children. In this cross sectional study, we collected 145 S. aureus isolates that caused skin and soft tissue and osteoarticular infections in pediatric patients of the Central Hospital I.P.S. in the period from December-2012 to November-2013. Resistance to clindamycin was determined by automated methods and double disc diffusion. PCR was performed for ermA, ermB, ermC and msrA genes from representative isolates. The global resistance to methicillin and clindamycin was 67 and 13%, respectively (11% attributable to the inducible mechanism). The ermC and msrA genes were detected individually in 25 and 17% of the isolates respectively while an isolate presented both genes simultaneously. The frequency of inducible resistance to clindamycin indicates the importance of double disc diffusion methods in microbiological practice, as well as being within the cut off points considered acceptable for the use of this antibiotic for skin infections. and osteoarticular caused by MRSA.

Analysis of coalescence process of methane hydrate in emulsion system

In oil and gas exploitation and pipeline transportation, hydrate formation poses a significant hidden danger to pipeline safety. Hydrates in the pipelines can coalesce easily on the inner wall surface. Therefore, studying the growth characteristics of hydrates in a multicomponent environment is crucial pipeline anti-blocking technology. Hence, two types of white oil emulsion, S85 + T20 and S85 + SDS, were prepared using sorbitol three oleic acid ester, polyoxyethylene sorbitol monoanhydride, and sodium dodecyl sulfate as dispersants. The mechanism of methane hydrate blockage in emulsion and particle systems at 40% moisture content was analyzed. The hydration reaction induction time and phenomenon characteristics of the two were compared, and the effect of the first 30 min particle size change on the hydration reaction was observed by focused beam reflectance measurement. The experimental results indicate that adding particles to the S85 + SDS emulsion system can shorten the time of hydration reaction dissolved gas significantly, while the hydrophilic particle system will reduce the droplet size at a certain concentration, inhibit the heat transfer and mass transfer between molecules, and prolong the induction of hydrate formation.

Intracellular Burkholderia Symbionts induce extracellular secondary infections; driving diverse host outcomes that vary by genotype and environment

Symbiotic associations impact and are impacted by their surrounding ecosystem. The association between Burkholderia bacteria and the soil amoeba Dictyostelium discoideum is a tractable model to unravel the biology underlying symbiont-endowed phenotypes and their impacts. Several Burkholderia species stably associate with D. discoideum and typically reduce host fitness in food-rich environments while increasing fitness in food-scarce environments. Burkholderia symbionts are themselves inedible to their hosts but induce co-infections with secondary bacteria that can serve as a food source. Thus, Burkholderia hosts are “farmers” that carry food bacteria to new environments, providing a benefit when food is scarce. We examined the ability of specific Burkholderia genotypes to induce secondary co-infections and assessed host fitness under a range of co-infection conditions and environmental contexts. Although all Burkholderia symbionts intracellularly infected Dictyostelium, we found that co-infections are predominantly extracellular, suggesting that farming benefits are derived from extracellular infection of host structures. Furthermore, levels of secondary infection are linked to conditional host fitness; B. agricolaris infected hosts have the highest level of co-infection and have the highest fitness in food-scarce environments. This study illuminates the phenomenon of co-infection induction across Dictyostelium associated Burkholderia species and exemplifies the contextual complexity of these associations.

The nature of voltage in superconductors with dynamic intermediate-mixed state

Aim: to describe scientific achievement providing the essence of the phenomenon; to confirm reliability of existence of DC electromagnetic induction using direct evidence.
 Methods: experimental research into magnetizing superconducting samples. Visualisation of intermediate and mixed state of superconductors and movement of quantised threads of magnetic flux, the beams of such threads. Development of mathematical theory on the basis of fractal geometry and functional analysis.
 Results: The essence of the scientific discovery consists in the proof that the direct consequence of the formation of an intermediate-mixed state of superconductors and the movement of quantum magnetic fluxes threads, beams of such filaments and macroscopic normal zones is the phenomenon of direct current electromagnetic induction.
 Conclusion: the discovery of DC electromagnetic induction has been made, superconducting topological electrical generators on the basis of DC electromagnetic induction have been built, that achieve high nominal parameters: 10-100 kA current, specific current load - 1 kA/kg.

Near-field thermal radiation between GaAs nanowires under magnetic field

We numerically investigate the near-field radiative heat transfer (NFRHT) between magneto-optical GaAs nanowires using both the local effective medium theory and fluctuational dissipation theorem. Under the action of magnetic field, the atoms or ions within magneto-optical materials will produce magnetic induction phenomenon, resulting in the orderly arrangement of the magnetic moment in NFRHT, which have not been paid enough attention. NFRHT between two aligned GaAs nanowires and plates under different magnetic field intensities is demonstrated, in which the Lorentz–Drude equations of dielectric constant tensor are proposed to describe the dielectric constant as a magnetic field applied on the GaAs nanowires. Moreover, we evaluate the near-field radiation between GaAs nanowires/plates with different filling ratios and gap distance under extent magnetic field. Furthermore, the electric field intensity is also presented for understanding light coupling, propagation, and absorption nature of GaAs grating under variable incidence angles and magnetic field strengths. The relative study is useful to the thermal radiative design in optical instruments.

On the Possible Anomaly of Asymmetric Weight Reduction of Gyroscopes under Rotation

In this work, we discuss a theoretical model that can describe novel phenomena of induction of weak anomalous forces in gyroscopes under right rotations either in rest frame of the laboratory or in free-fall. The effect detected in the gyroscopes cannot be successfully associated to any conventional theory. So, we elaborated the theoretical description of such forces in both experiments by means of a model based on the generalized quantum entanglement framework, by considering as quantum witnesses the magnetic permeability and as macroscopic observable the angular momentum of the gyroscopes rotors. Our calculations indicate that there is a good agreement with the experimental data obtained from literature for most rotation frequencies measured.

Theoretical and experimental evaluation of electromagnetic induction from power line upon multi-points grounded conductors

Electromagnetic induction between power lines and telecommunication cables may cause physical injury of service personnel, and malfunction or quality degradation of telecommunication services. Therefore, the influence of electromagnetic induction on telecommunication cables has been studied since early 1900’s. However, due to a complicated configuration and multi-point connection to the ground, there were few studies on induction phenomenon to a suspension wires that support overhead telecommunication cable. In this paper, we have studied on induction phenomena upon multiple point grounded conductors, theoretically and experimentally. As a result, we confirmed that calculated and measured results are in good agreement with ideal conditions.

Characteristic Analysis of Induction Phenomena in the Nearby Mesh Structure Conductive Part of Large Capacity Wireless Power Transmission System

Characteristic Analysis of Induction Phenomena in the Nearby Mesh Structure Conductive Part of Large Capacity Wireless Power Transmission System

STEM підхід у навчанні фізики майбутніх інженерів: вивчення явища електромагнітної індукції

Постановка проблеми. Актуальність впровадження STEM підходу у вивченні курсу загальної фізики визначається необхідністю формування компетенцій проведення практико орієнтованих досліджень вже з молодших курсів: науковий та інженерний методи пізнання дійсності формують у майбутніх інженерів наукову і техніко-технологічну картини світу. Аналіз попередніх досліджень. Явище електромагнітної індукції– комплексна і складна тема з курсу загальної фізики; яка водночас має широке практичне застосування. Сучасний натурний фізичний експеримент є універсальним засобом для набуття майбутніми фахівцями відповідних дослідницьких компетенцій; комп’ютерно орієнтована система фізичного експерименту ефективно формує загальнонаукові і професійні навички майбутніх інженерів. Метою роботи було дослідження дидактичних особливостей використання наукового та інженерного (STEM) методів дослідження у вивченні майбутніми інженерами явища електромагнітної індукції у курсі загальної фізики. Методи: застосовано теоретичні і емпіричні методи наукового дослідження: методи аналізу і моделювання; педагогічний експеримент; обсерваційні і праксиметричні методи для визначення дієвості; ефективності і практичної придатності методичної системи. Результати і дискусія. Вивчення явища електромагнітної індукції з використанням компютерно орієнтованої системи фізичного експерименту демонструє етапи наукового методу дослідження; який починається з формулювання проблеми; побудови теоретичних моделей; продовжується висуненням гіпотези з подальшою експериментальною перевіркою; опрацюванням експериментальних даних; їх інтерпретацією; пошуком додаткової інформації; коригуванням експерименту; висуненням нових гіпотез і їх подальшою перевіркою STEM підхід у дослідженні ЕМІ було реалізовано відповідно до інженерного методу дослідження здійснювалось через етапи проектування; до яких входять: мозковий штурм; висування способів реалізації установки; підбір матеріалів; створення дослідного зразка та його багаторазове випробування. Висновки.Застосування різних підходів; орієнтованих як на наукове дослідження у рамках компютерно орієнтованої системи фізичного експерименту; так і на інженерний метод з використанням STEM навчання виявили практичну придатність; дієвість та ефективність: реалізація поставленої мети потребувала залучення і розвитку різного рівня компетенцій від алгоритмізованих дій до творчого підходу у випадку самостійного створення експериментальної установки. Виявлено; що за своїм змістом і метою STEM є інженерним методом у навчально-науковому дослідженні. Розробки і подальшого розвитку потребують організаційно-педагогічні умови реалізації методичної системи навчання фізики майбутніх інженерів з використанням STEM.

Experimental investigations on co-rotating vortex pair merger in convergent/divergent channel flow with single-side-wall deflection

The co-rotating vortex pair merger in the convergent and divergent channel flow was investigated in both equal and unequal cases. The crossflow flow phenomenon of vortex pair merger was acquired by applying particle image velocimetry in a series of streamwise locations. The main finding is that the resultant single-side-wall deflection convergent and divergent channel flow can vary the merging rate and merging trajectories of the equal vortex pair. In the unequal vortex merger, distortion and absorption of the weaker vortex by the stronger vortex were observed, which is different from the mutual induction phenomenon in the equal strength vortex pair case. Furthermore, it was found that the flow converging and diverging have common effects on the merging process in both equal and unequal vortex merger. In the convergent channel flow, vortex pair separation experienced early reduction at upper stream locations, and the merger was accelerated. As the vortex pair developed further downstream, the difference in the merger progress among different channel flow environments becomes less significant, which is believed to be due to the combined effect of pressure gradient and developing time variations.

Modeling induction phenomena in amino acid cation– $$\pi $$ π interactions

Cation– $$\pi $$ interactions are widely recognized as an important class of interactions, notably in biology and supramolecular chemistry, participating in molecular recognition and association phenomena. Numerical simulations relying on additive force fields perform usually poorly in modeling precisely these interactions. It is now well established that accurate reproduction of the interaction energy of a positively charged group bound to the $$\pi $$ -electron cloud of an aromatic ring requires an explicit treatment of induction effects by means of polarizable potentials. In this contribution, we compare critically the ability of the CHARMM Drude polarizable force field to describe a series of prototypical cation– $$\pi $$ interactions observed in proteins with that of the pairwise additive CHARMM36 force field. Toward this end, potentials of mean force characterizing the binding of amino acid side-chain models, namely ammonium and guanidinium cations, on the one hand, and toluene, para-cresol and 3-methylindole, on the other hand, have been determined within the extended adaptive biasing force framework.

Effects of 2-aryl-1-cyano-1,2,3,4-tetrohydroisoquinolines on apoptosis induction mechanism in NB4 and MKN-45 cells

Our previous study found that 2-aryl-1-cyano-1,2,3,4-tetrahydroisoquinolines (CATHIQs) have excellent anti-cancer activity and obvious apoptosis induction phenomenon. As our continuing research, this study further explored their underlying molecular mechanism of apoptosis induction in cancer cells. Flow cytometry analysis showed that the NB4 cells treated by 1-cyano-2-(2-fluorophenyl)-1,2,3,4-tetrahydroisoquinoline or the MKN-45 cells treated by 1-cyano-2-(4-trifluoromethylphenyl)-1,2,3,4-tetrahydroisoquinoline for 48 h were at early stage of apoptosis, and the cell cycle arrest was only slightly affected. Apoptosis rates of the cells significantly increase with the treatment concentration of the compounds. The compounds could significantly decrease the activities of SOD, raise the MDA level and promote the LDH leakage, suggesting that the excessive formation of ROS should be involved in the cell apoptosis. Western blot analysis showed that the compounds improved both Bax/Bcl-2 ratio and cleavages of procaspase-3, promoted efflux of cytochrome c to cytosol and phosphorylation of p38 and JNK, and attenuated phosphorylations of Akt and ERK. Together, inhibitions of PI3K/Akt and ERK and activation of p38 mediated the compounds-induced apoptosis through modulating the mitochondrial pathway and/or ROS production.

Complementary surrounds explain diverse contextual phenomena across visual modalities.

Context is known to affect how a stimulus is perceived. A variety of illusions have been attributed to contextual processing-from orientation tilt effects to chromatic induction phenomena, but their neural underpinnings remain poorly understood. Here, we present a recurrent network model of classical and extraclassical receptive fields that is constrained by the anatomy and physiology of the visual cortex. A key feature of the model is the postulated existence of near- versus far- extraclassical regions with complementary facilitatory and suppressive contributions to the classical receptive field. The model accounts for a variety of contextual illusions, reveals commonalities between seemingly disparate phenomena, and helps organize them into a novel taxonomy. It explains how center-surround interactions may shift from attraction to repulsion in tilt effects, and from contrast to assimilation in induction phenomena. The model further explains enhanced perceptual shifts generated by a class of patterned background stimuli that activate the two opponent extraclassical regions cooperatively. Overall, the ability of the model to account for the variety and complexity of contextual illusions provides computational evidence for a novel canonical circuit that is shared across visual modalities. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

컴솔 멀티피직스를 이용한 양극형 1회선 HVDC의 전계 해석

Recently, there has been an increasing interest in HVDC(High Voltage Direct Current) transmission as a core technology required for a Super grid. Compared with HVAC(High Voltage Alternating Current) transmission, HVDC transmission has no loss due to skin effect and reactance components, so long-distance power transmission is possible, and asynchronous power system can be interconnected. Also, in case of a DC electric field, there is no induction phenomenon. However, the human body may cause irritation such as electrostatic discharge and discomfort, therefore electric field analysis through simulation is absolutely necessary. In this paper, electric field simulation was performed using COMSOL Multiphysics, a multi-physics analysis program, for a Bipolar single line DC ±400kV, DC ±500kV, DC ±800kV model. In order to verify the validity of the simulation, comparative analysis with the related literature was conducted.