cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Arhaeoastronomical research of Chashkovsky Ridge
Creators: name: Polyakova O., O.
Publisher: name: Archaeoastronomy and Ancient Technologies
Year: 2013
Subjects: РИТУАЛЬНЫЙ КОМПЛЕКС
КАЛЕНДАРЬ
РАВНОДЕНСТВИЕ
СОЛНЦЕСТОЯНИЕ
RITUAL COMPLEX
CALENDAR
EQUINOX AND SOLSTICE

description: This paper is devoted to research on arheoastronomicheskim Chashkovskom ridge spur Ilmeny Southern Urals, in conjunction with mountain Golukha and lake Large Elancik. This entity is the central research hole on the top of the mountain and view it from a review of the horizon. Hull has a natural origin, but artificially increased by ancient people for not yet clear goals for us. To check the version of astronomical taken a photocall at the equinoxes and solstices. Pre-map were conducted prospective observation direction of sunrise and sunset on the dates indicated year. Especially interesting was the eastern direction, which indicated two small slides and a long peninsula lake Big Elancik. Checking directions on mountain confirmed the sunrise at the equinox of the base nearest hills to the east, and from the long peninsula on the lake the sun set in the west. No less interesting was the direction of the sunrise at the winter solstice of two hollow hills on the south-east. It is safe to conclude that on the mountain Golukha in several millennia conducted astronomical observations are likely to calendaring. Assumptions are confirmed chance finds of fragments of ceramics and stone tools on the mountain and on the lake.
Causes of agitation for one Prairie province
Creators: name: Brangwin, Christopher James
Publisher: name: University of British Columbia
Year: 2011

description: The specific objective of this thesis is to examine the causes of agitation for the establishment of one province to encompass the three existing provinces of Alberta, Saskatchewan and Manitoba, or the Prairie region. Regional studies are hampered by the somewhat elusive meaning of 'region’. It is argued here, however, that the Prairies constitute a distinctive region of Canada, and such argument can be defended by looking into the historical, cultural and economic need for Prairie people to adopt a collective philosophy towards their lives concerning common goals, and, more recently, an antagonism towards Eastern Canadian economic domination over the Prairie provinces. Such a view of the three Prairie provinces has many times stimulated the question - Why don't they join together and create one Prairie province? The Conference to discuss this question was most recently held at Lethbridge, Alberta, and from the proceedings of this conference comes the stimulus and interest in this topic. A further objective is to identify the interesting growth of co-operative organisations which transcend political boundaries within the Prairies. It is suggested that these are in direct response to the fact that the region needs a co-operative approach to many of the problems that are faced by the whole region. This is indeed a cause for agitation in that integration is increasing in the Prairies. Argument can be made that political unification is the ultimate step. It must be pointed out that the writer has not taken a stand on the advisability of the idea, but merely to identify the bases of the agitation for it. The method of investigation in this work is to determine the extent to which the Prairie provinces could be considered to have an identity which points particularly to the Western alienation question. A measure of the following for the idea of Prairie union is given. This is examined with regard to the increasing number of organisations that concern themselves with a Prairie hinterland, as opposed to an area of influence contained by the political borders of one of the Prairie provinces. The conclusion is that the Prairies do have a definable identity which is predominantly a result of the feeling of Western alienation in the Prairies. The desire to control their own future stimulates the growth of Prairie organisations. The agitation for Prairie unity does not necessarily express itself in terms of a political union, but in terms of Prairie co-operation.
One Promise of 5G: Everyday Millimeter Waves: What This Means for Standards and Measurements Slides
Creators: Roger Nichols
Publisher: name: IEEE
Year: 2018

MTT Webinar Slides
5G appears to be upon us. In June the 3GPP has announced the completion of the Release-15 standard in June—the first drop of which was announced last December. Multiple mobile operators around the world have announced commercialization timing and the industry is struggling to address the mix of hype, new technology, and very aggressive schedules. Release-15 includes radio capabilities in the sub 6GHz range (FR1) as well as for millimeter-wave frequencies from 24-52GHz (FR2). The addition of the millimeter-wave spectrum to commercial wireless has pulled a new and wider audience into the arena of managing highly-directional radio propagation. The 5G commercial wireless industry will have scale, cadence, and cost pressures that the aerospace & defense and satellite industries have yet to confront. These new cost and time-pressures impact designs, materials and lifecycles—and, of course, putting a quantitative measure on their performance and functionality is no small part of that impact. Test and measurement of these systems means using heretofore expensive equipment, time-consuming procedures, over-the-air techniques, and new end-to-end validation processes based on an unprecedented mobile use-model. The newness of FR2 means that the standard still has ways to go. The list of exceptions in Rel-15 and the number of items deferred to Rel-16 is a good indicator of what is yet to be done. And as of July, 2018, 3GPP RAN4 and RAN5 are still engaged in discussions (and not yet decisions) about over-the-air test methods (and their dramatic impact on measurement uncertainty) for such mundane measurements as power, spurious emissions, spectral emissions (SEM), and error-vector magnitude (EVM); and much work is still to be done for receiver measurements. This webinar covers the status of the 3GPP NR spec and some of its impacts on hardware and system design. It also covers some examples of the tough measurement challenges confronting the industry as well as what to expect as the standard and the industry evolve.
Dynamical behaviour of the `beads' along the magnetic field lines near a rotating black hole
Creators: name: Cao, Xinwu
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The elements of the cold magnetic driven flows behave like beads on the magnetic field line. The inclination of the field lines at the surface of the disc plays a crucial role on the nature of the magnetically driven outflow. For the non-relativistic case, a centrifugally driven outflow of matter from the disc is possible, if the poloidal component of the magnetic field makes an angle of less than a critical 60 degrees with the disc surface. The collimated flows ejected from active galactic nuclei may probably start from the region near the black hole. We investigate the dynamical behavior of the 'beads' on the magnetic field line start from the disc near a black hole. It is found that the critical angle becomes larger than 60 degrees for the rotating black hole case (close to 90 degrees for a=1), which may imply that the flows are easy accelerated in the inner edge of the disk surrounding a rotating black hole.
Cosmology and Astrophysics with the Diffuse eRASS1 X-ray Angular Power Spectrum
Creators: name: Lau, Erwin T.
name: Bogdán, Ákos
name: Nagai, Daisuke
name: Cappelluti, Nico
name: Shirasaki, Masato
Publisher: name: arXiv
Year: 2024
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The recent tension in the value of the cosmological parameter $S_8 \equiv σ_8(Ω_M/0.3)^{1/2}$, which represents the amplitude of the matter density fluctuations of the universe, has not been resolved. In this work, we present constraints on $S_8$ with the X-ray angular power spectra of clusters and groups measured with the half-sky map from the eROSITA All Sky Survey data release 1 (eRASS1). Thanks to the extensive sky coverage of eRASS1, it achieves unprecedented precision compared to previous power spectrum measurements. Using a well-calibrated, physical halo gas model that includes astrophysics of feedback and non-thermal pressure support, we obtain $S_8 = 0.80^{+0.02}_{-0.01}$ with 1$σ$ uncertainty that is competitive against other cosmological probes. Our derived $S_8$ value is smaller than the primary CMB measurements from {\em Planck}, but still consistent to within $1σ$. We also obtain constraints on the astrophysics of feedback, non-thermal pressure, equation of state in cluster cores, and outer boundaries of gas in clusters and groups. We discuss how additional X-ray observations, and cosmological surveys in microwave and optical, will further improve the cosmological constraints with the angular power spectrum. Our work demonstrates that the angular power spectrum of clusters and groups is a promising probe of both cosmology and astrophysics.
description: 13 pages, 5 figures, ApJ accepted. Updated to match the accepted version
IoT and 5G Future Evolution the Role of RF Technologies Slides
Creators: Nuno Borges Caravalho
Publisher: name: IEEE
Year: 2017

MTT Webinar Slides
IoT and 5G have different energy needs. In this talk an overview of the energy problem in wireless communication systems will be presented, either from a mobile network point of view, but also from a IoT point of view. The main objective is to discuss future wireless paradigms that will be changing soon with 5G and beyond, those include the spread of a distributed mobile network by using Cloud Radio Access Networks, with its associated Software Defined Radio approaches, but also the issue of battery-less wireless devices, combining wireless power transmission and backscatter communications. The talk starts first with a general overview of the energy needs for a future XG networks, and then presents in an integrated way both approaches of C-RAN and IoT wireless design. The presentation will cover topics like the hardware part of the SDR and design of battery-less wireless sensors networks. Issues like characterization of mixed-signal devices, designing of C-RAN SDR approaches, design of passive backscatter sensors will be discussed, according to the audience.
Megalithic structures and dolmen orientation in Bulgaria
Creators: name: Tsonev L., V.
name: Kolev D., Z.
Publisher: name: Archaeoastronomy and Ancient Technologies
Year: 2013
Subjects: MEGALITHIC MONUMENT
THRACIAN DOLMEN
SUN GOD
NORTH SAKAR MOUNTAIN
ARCHAEOASTRONOMY

description: A review of the main types of megalithic and quasi-megalithic monuments in Bulgaria is presented together with maps of their localization. A large and modern data base about the orientation of 110 Thracian dolmens (XII-VII c. BC) is interpreted in detail. The astronomic orientation principle is tested. The azimuths occupy wide sectors in South excluding the generalized north direction, but there is a little evidence for astronomically significant orientations. Looking for additional orientation principles we made a topographic analysis of dolmens. It was found that in numerous cases dolmens are oriented towards some height or peak on which ancient rock-cut sanctuary exists. Another curious principle was observed in a dolmen group in North Sakar Mountain: the neighborhood principle. As a next step the orientation of the dolmens was compared with the orientation of the classic temples under tumuli in the Thracian region (VI c. BC III c.). The interaction between continuity and evolution is proved: the main dolmen orientation principle towards the Sun god has been preserved in the temple orientation in the next epoch.
Mode-Selective Photonic Lanterns with Double-Clad Fibers
Creators: name: Becerra-Deana, Rodrigo Itzamná
name: de Sivry-Houle, Martin Poinsinet
name: Virally, Stéphane
name: Boudoux, Caroline
name: Godbout, Nicolas
Publisher: name: arXiv
Year: 2024
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We present the design, fabrication, and characterization of mode-selective photonic lanterns using double-clad fibers. Here, we exploited several custom-pulled double-clad fibers to achieve the symmetry break required to excite higher-order modes. The resulting components are short and exhibit high modal isolation and low excess loss. They address some of the limitations of existing photonic lanterns in terms of fragility and coupling efficiency. The fabrication process involves the use of lower-index capillary tubes to maintain fiber geometry during fusion and tapering. Through the use of varying first cladding diameters, mode selectivity is achieved without sacrificing single-mode compatibility. This in turn allows proper real-time characterization during the whole fabrication process. Results demonstrate that double-clad fibers stacked inside a fluoride-doped capillary tube feature high modal isolation (above 60dB) and low excess loss (lower than 0.49dB), over a broad wavelength range (more than 250nm) with steeper taper profiles, and more robust components. The use of less expensive synthetic fused silica capillary tubes achieves high modal isolation (above 20dB) and excess loss lower than 2dB over the same broad wavelength range.
description: 6 pages, 5 figures, This work has been submitted to the IEEE for possible publication
Microchilo Okano 1962
Creators: name: Léger, Théo
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Lepidoptera
Crambidae
Microchilo

description: Microchilo Okano, 1962
Microchilo Okano, 1962 a: 129.
Type species: Microchilo inouei Okano, 1962
DIAGNOSIS
Species of Microchilo exhibit short greyish forewings. Okano (1962) provides a diagnostical description of the genus. Forewing very small (4-8 mm), greyish white, brown or grey; antemedian and postmedian lines present. Male genitalia with the following characters: uncus wide at base, medially narrowed, apex rounded; gnathos with very short, pointed projection; tegumen arms relatively short; valva narrow, costa sclerotized, produced at apex into a spine pointed upwards or outwards; saccus conspicuously protruding anterad; vesica with or without cornuti (Okano, 1962; pers. obs.). Female genitalia have the following characters: papillae anales minute, connected dorsally, free ventrally; posterior and anterior apophyses very long; intersegmental membrane VIII-IX roughly 2 X length of tergite VIII; antrum membranous or sclerotized, tubular; ductus bursae rather short, in some species covered with minute spines, often straight; corpus bursae often with short, streak-like signum (Okano, 1962; pers. obs.).
DISTRIBUTION
Distributed in Eastern Palearctic (Japan, continental China) and Oriental regions. Four species are newly described here for the Philippines: Microchilo bundoki sp. n., Microchilo cebuano sp. n., Microchilo spinosus sp. n., Microchilo imminutela sp. n.
PHYLOGENETIC RELATIONSHIPS
Microchilo has been placed by Gaskin in the Diptychophorini (Gaskin, 1971), but molecular analyses suggest the genus belongs to the “narrow-winged clade,” sister to the Diptychophorini (Léger et al., 2019).
description: Published as part of Léger, Théo, 2024, Half of the Diversity Undescribed: Integrative Taxonomy Reveals 32 New Species and a High Cryptic Diversity in the Scopariinae and Crambinae of the Philippines (Lepidoptera: Crambidae), pp. 1-93 in Bulletin of the Society of Systematic Biologists 3 (2) on page 76, DOI: 10.18061/bssb.v3i2.9527, http://zenodo.org/record/15116964
Nonlinear Modeling and Characterization of Microwave Devices and Circuits for High Power Amplifier Applications Slides
Creators: J.C. Pedro
Publisher: name: IEEE
Year: 2017

MTT Webinar Slides
Despite more than 40 years have already passed since the dawn of the first circuit simulator, modeling and characterization of nonlinear microwave circuits hasn’t yet reached most bachelor’s and master’s electrical engineering curricula. Therefore, the vast majority of microwave designers still cannot profit from the significant technological advancements that have been made on active device modeling and specific laboratory instrumentation for model extraction and performance verification. So, they tend to conduct their designs relying on experience, heuristic concepts – many times plagued by hidden but erroneous, linear assumptions, and many trial and error iterations in the lab. Addressing both the nonlinear device modeling tools and their required device characterization instruments and procedures, from both a fundamental but also practical perspective, this webinar has a twofold objective. First it is meant to bring the recent advances made on these fields to the practicing microwave engineer. Second, it is aimed at attracting researchers and graduate students to pursue further studies on these scientifically exciting topics. Starting from the mostly used nonlinear equivalent-circuit and behavioral modeling methods, we will then move on to address the laboratory instrumentation  devoted to measure the device characteristics needed for model extraction and performance assessment. A special attention will be given to model modern non-quasi-static microwave actives devices, such as high-power GaN HEMTs, and the new measurement instruments and setups required for their laboratory characterization. Finally, a power amplifier application example will be presented, in which we will illustrate the impact that a good model may have on the actual circuit design process.
Regio-selective synthesis and activity research on 7-icaritin norcantharidin conjugates
Creators: name: Dong, Weiwei
name: Wang, Xianheng
name: Qian, Shuang
name: Wang, Yuhe
name: Zhao, Changkuo
Publisher: name: Taylor & Francis
Year: 2022
Subjects: subject: Biochemistry
subject: Medicine
subject: Genetics
subject: FOS: Biological sciences
subject: Pharmacology
subject: Biotechnology
subject: Chemical Sciences not elsewhere classified
subject: Biological Sciences not elsewhere classified
subject: Cancer

description: Due to complexity of tumor diseases and resistance of targeted drug, targeted drug usually cannot meet the needs of cancer treatment. Therefore, the conjugate constructed by two anticancer agents maybe a better solution for the tumor diseases. As natural anticancer agents, icaritin and norcantharidin are selected for the construction of conjugate. In the condition of EDCI/DMAP, icaritin is reacted with norcantharidin esters to give the desired 7-esters selectively in a moderate yield. MTT method was used to test the cytotoxicity and intensity on Hep G2 and MCF-7 in vitro. Some of the compounds (4a, 4i and 4j) show a better inhibition against Hep G2 and MCF-7 cell lines in vitro, and are deserved to be a potential drug candidate to develop in vivo.
Solving the Kinetic Ising Model with Non-Reciprocity
Creators: name: Weiderpass, Gabriel Artur
name: Sharma, Mayur
name: Sethi, Savdeep
Publisher: name: arXiv
Year: 2024
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: High Energy Physics - Theory (hep-th)
subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Physical sciences

description: Non-reciprocal interactions are a generic feature of non-equilibrium systems. We define a non-reciprocal generalization of the kinetic Ising model in one spatial dimension. We solve the model exactly using two different approaches for infinite, semi-infinite and finite systems with either periodic or open boundary conditions. The exact solution allows us to explore a range of novel phenomena tied to non-reciprocity like non-reciprocity induced frustration and wave phenomena with interesting parity-dependence for finite systems of size $N$.
 We study dynamical questions like the approach to equilibrium with various boundary conditions. We find new regimes, separated by $N^{th}$-order exceptional points, which can be classified as overdamped, underdamped and critically damped phases. Despite these new regimes, long-time order is only present at zero temperature. Additionally, we explore the low-energy behavior of the system in various limits, including the ageing and spatio-temporal Porod regimes, demonstrating that non-reciprocity induces unique scaling behavior at zero temperature. Lastly, we present general results for systems where spins interact with no more than two spins, outlining the conditions under which long-time order may exist.
description: 74 pages, LaTeX, 13 figures; published version with additional comments and references
Cold and Ultracold Molecules: Science, Technology, and Applications
Creators: name: Carr, Lincoln D.
name: DeMille, David
name: Krems, Roman V.
name: Ye, Jun
Publisher: name: arXiv
Year: 2009
Subjects: subject: Quantum Physics (quant-ph)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Atomic Physics (physics.atom-ph)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: This article presents a review of the current state of the art in the research field of cold and ultracold molecules. It serves as an introduction to the Special Issue of the New Journal of Physics on Cold and Ultracold Molecules and describes new prospects for fundamental research and technological development. Cold and ultracold molecules may revolutionize physical chemistry and few body physics, provide techniques for probing new states of quantum matter, allow for precision measurements of both fundamental and applied interest, and enable quantum simulations of condensed-matter phenomena. Ultracold molecules offer promising applications such as new platforms for quantum computing, precise control of molecular dynamics, nanolithography, and Bose-enhanced chemistry. The discussion is based on recent experimental and theoretical work and concludes with a summary of anticipated future directions and open questions in this rapidly expanding research field.
description: 82 pages, 9 figures, review article to appear in New Journal of Physics Special Issue on Cold and Ultracold Molecules
Hybrid Quantum Cosmology: Combining Loop and Fock Quantizations
Creators: name: Marugan, Guillermo A. Mena
name: Martin-Benito, Mercedes
Publisher: name: arXiv
Year: 2009
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: As a necessary step towards the extraction of realistic results from Loop Quantum Cosmology, we analyze the physical consequences of including inhomogeneities. We consider in detail the quantization of a gravitational model in vacuo which possesses local degrees of freedom, namely, the linearly polarized Gowdy cosmologies with the spatial topology of a three-torus. We carry out a hybrid quantization which combines loop and Fock techniques. We discuss the main aspects and results of this hybrid quantization, which include the resolution of the cosmological singularity, the polymeric quantization of the internal time, a rigorous definition of the quantum constraints and the construction of their solutions, the Hilbert structure of the physical states, and the recovery of a conventional Fock quantization for the inhomogeneities.
description: 24 pages, published in International Journal of Modern Physics A, Special Issue: Proceedings of the Second Workshop on Quantum Gravity and Noncommutative Geometry (Lisbon, Portugal)
The Load Modulated Balanced Amplifier Slides
Creators: Steve Cripps
Publisher: name: IEEE
Year: 2018

MTT Webinar Slides
Quadrature-balanced amplifiers hold a revered position in the historical development of broadband microwave amplifiers up to 20 GHz and beyond, because they replaced unreliable traveling wave tubes (TWTs) with solid-state equivalents. After declining in popularity when monolithic microwave integrated circuits (MMICs) entered the market, they are now becoming useful again due to research at Cardiff and University of Colorado, Boulder showing a surprising and counter-intuitive property that allows active load modulation of the output match presented to the balanced transistors. This has enabled broadband matching network design to break away from conventional constraints and has opened up application avenues in high efficiency RF power amplifier (RFPA) design, both in telecommunication and electronic countermeasure (ECM) bands.
Conversations with Data: How Data Journalism Affects Online Comments in the New York Times
Creators: name: Kantor, Avner
name: Rafaeli, Sheizaf
Publisher: name: arXiv
Year: 2024
Subjects: subject: Computers and Society (cs.CY)
subject: Social and Information Networks (cs.SI)
subject: FOS: Computer and information sciences

description: Users in the data age have access to more data than ever before, but little is known how they interact with it. Using transparency and multimedia, data journalism (DJ) lets users explore and interpret data on their own. This study examines how DJ affects online comments as a case study of user interactions with data. The corpus comprises 6,400 stories and their comment sections from the DJ and other sections of the New York Times, from 2014-2022. Results indicate that DJ is positively associated with higher level of interactivity between the users. This relationship is mediated by statistical information, information sources, and static visualizations. However, there is a low level of interactivity with the content; consequently, only part of the users use it. The results demonstrate how data accessibility through DJ engages the users in conversation. According to deliberation theory, this creates a conducive environment for democratic processes.
Electron Holes and Heating in the Reconnection Dissipation Region
Creators: name: Che, H.
name: Drake, J. F.
name: Swisdak, M.
name: Yoon, P. H.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Pattern Formation and Solitons (nlin.PS)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: Using particle-in-cell simulations and kinetic theory, we explore the current-driven turbulence and associated electron heating in the dissipation region during 3D magnetic reconnection with a guide field. At late time the turbulence is dominated by the Buneman and lower hybrid instabilities. Both produce electron holes that co-exist but have very different propagation speeds. The associated scattering of electrons by the holes enhances electron heating in the dissipation region.
description: 14 pages, 5 figures, submitted to GRL
Topic construction and speaker involvement : some features of the social organization of meetings
Creators: name: Amren, Rudolph Wayne
Publisher: name: University of British Columbia
Year: 2011

description: Two brief excerpts of transcribed talk from the First Annual General Meeting of a Co-operative Association, and some additional background information from 'field observations', are taken as data for the study of participants' organization of that occasion through their conversational practices. Employing a methodological perspective directed toward the discovery of the formal structures of practical actions first proposed by Harold Garfinkel and Harvey Sacks,² ³ ⁶ a descriptive analysis is offered of members strategies for constructing this talk as socially organized activity. We find, through the activities of 'beginning', '.constructing a way of proceeding', 'constructing a first item of business', and 'keeping track of topics and speakers', that the occasion is constituted as a 'meeting'; and by noting the resources called upon in 'constructing topics' and 'doing membership categorization' we find the production and display of that occasioned-group as a 'meeting of a formal organization'. With respect to topic-choice and speaker-selection problems, we observe that a fundamental aspect of the character of that group-occasion is provided in their particular solution, the propriety of which turns on the interpretive scheme provided via the 'reasons for the meeting'. We have also shown how 'invoking authorship', 'doing biographical analysis', and 'calling for an autobiographical account may be directly implicated in controlling the talk at that point in the occasion. Numerous other features of these activities are discussed with a similar concern for displaying how they are ‘situated’ with respect to such resource classes as 'the Co-op Organization', and 'the sequential organization of that occasioned talk'. In retrospect, and by way of characterizing what we have accomplished in the analysis, we are able to relate some of our findings to published material in the field. If we are permitted to extrapolate from our experience with these two small excerpts of talk, we are led to conclude that further study of 'the meeting', as a pervasive and accessible form of social activity, promises to contribute to our understanding of the social organization of multi-person gatherings and the production of occasioned talk in natural settings.
Gallium Nitride Power MMICs Fact and Fiction Slides
Creators: Charles Campbell
Publisher: name: IEEE
Year: 2017

MTT Webinar Slides
Gallium Nitride (GaN) based transistor technology’ characteristics of very high current density combined with high voltage operation have held promise to vastly improve many microwave circuit applications that presently utilize Gallium Arsenide (GaAs) devices. Today, GaN transistors are capable of high voltage operation while simultaneously demonstrating FT & Fmax characteristics more typical of lower voltage GaAs PHEMT devices. The potential benefits of GaN device characteristics combined with monolithic microwave integrated circuit (MMIC) technology are many. Highly efficient switched modes of power amplifier operation should be possible at higher output power levels and frequency. High output impedance typical of transistors operated at three to five times the voltage of GaAs should facilitate lower loss matching networks due to the reduced transformation ratio. Alternately, transistor periphery and corresponding output power could be dramatically increased while maintaining impedance transformation ratios similar to that  of existing GaAs PHEMT amplifiers. The higher output power density of GaN devices should lead to greatly reduced die size for GaN implementations of existing power amplifier functions. The improved heat flow realized by the high thermal conductivity Silicon Carbide (SiC) substrate material should allow for acceptable junction temperatures even with the much higher power dissipation. Very high power switches could be designed by using large control voltages and taking advantage of the high current capability (high Imax) of GaN. While the advantages of GaN are manifest, many of the features that make GaN transistors attractive can be shown to create significant issues that are typically not encountered with lower voltage technologies. In this talk, examples and scenarios are discussed highlighting the benefits and issues associated GaN MMIC technology.
Design of Scalable and Low Complexity Phased Arrays Slides
Creators: Amir Mortazawi
Publisher: name: IEEE
Year: 2019

MTT Webinar Slides
Recent requirements in 5G communication and advanced driver assistant systems have drawn an increasing interest in utilizing phased array technologies. Bandwidth intensive applications such as real-time video streaming and emerging gigabit wireless communications demand higher data rates than ever before. The spatial selectivity of phased arrays can increase the channel capacity and data rate without requiring extra bandwidth. Furthermore, the spatial filtering nature of the phased array systems alleviate the problem of multipath fading and co-channel interference by suppressing signals emanating from undesirable directions. Unfortunately, the high cost of phased arrays has been the primary impediment to their deployment in many commercial applications. Several new approaches for the design of new phase shifters and phased arrays will be presented to reduce the size, cost and complexity of the conventional phased arrays.
Distance functions on convex bodies and symplectic toric manifolds
Creators: name: Fujita, Hajime
name: Kitabeppu, Yu
name: Mitsuishi, Ayato
Publisher: name: arXiv
Year: 2020
Subjects: subject: Metric Geometry (math.MG)
subject: FOS: Mathematics
subject: Primary 53D20, Secondary 53C23, 52B12

description: In this paper we discuss three distance functions on the set of convex bodies. In particular we study the convergence of Delzant polytopes, which are fundamental objects in symplectic toric geometry. By using these observations, we derive some convergence theorems for symplectic toric manifolds with respect to the Gromov-Hausdorff distance.
description: 19 pages
Number Pi from the decorations of ancient artifacts
Creators: name: Sparavigna A., C.
Publisher: name: Archaeoastronomy and Ancient Technologies
Year: 2013
Subjects: HISTORY OF SCIENCE
MATHEMATICS OF BRONZE AGE

description: The decorations of ancient objects can provide some information on the value of constant π as a rational number, known and used by the artists who made them. Number π is the dimensionless ratio of circumference to diameter, and then, by measuring the ancient decorations we can obtain its value and gain some hints on the human knowledge of mathematics and geometry in prehistoric times. Here we discuss two examples of this approach. The first is concerning some disks found in the tomb of Hemaka, the chancellor of a king of the First Dynasty of Egypt, about 3000 BC. The second is the decoration composed by several circles and spirals of the Langstrup belt disk, an artifact of the Bronze Age found in Denmark.
Exploring the properties of quantum scars in a toy model
Creators: name: Sinha, Sudip
name: Sinha, S.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We introduce the concept of ergodicity and explore its deviation caused by quantum scars in an isolated quantum system, employing a pedagogical approach based on a toy model. Quantum scars, originally identified as traces of classically unstable orbits in certain wavefunctions of chaotic systems, have recently regained interest for their role in non-ergodic dynamics, as they retain memory of their initial states. We elucidate these features of quantum scars within the same framework of this toy model. The integrable part of the model consists of two large spins, with a classical counterpart, which we combine with a random matrix to induce ergodic behavior. Scarred states can be selectively generated from the integrable spin Hamiltonian by protecting them from the ergodic states using a projector method. Deformed projectors mimic the `quantum leakage' of scarred states, enabling tunable mixing with ergodic states and thereby controlling the degree of scarring. In this simple model, we investigate various properties of quantum scarring and shed light on different aspects of many-body quantum scars observed in more complex quantum systems. Notably, the underlying classicality can be revealed through the entanglement spectrum and the dynamics of `out-of-time-ordered correlators'.
Nonlinear Microwave Circuits Part II Design of High Efficiency Power Amplifier Using Nonlinear Embedding Slides
Creators: Patrick Roblin
Publisher: name: IEEE
Year: 2017

MTT Webinar Slides
In Part II of this Webinar, we will explore how NVNA’s also find applications in the design of power amplifiers (PA). To optimize the power efficiency of PAs, specific internal modes of operation are usually targeted at the device current source reference planes as estimated using nonlinear de-embedding. However given the tremendous large search space for the multi-harmonic terminations for waveform engineering, it is beneficial to first use a nonlinear embedding device model to predict from the desired internal mode of operation, the required amplitude and phase of the multi-harmonic incident waves at the transistor measurement reference planes. The verification of the resulting amplifier power efficiency optimization can then be performed using NVNA measurements. Examples of such design for Doherty and Chireix amplifiers will be presented. Finally in addition to CW signals, pulsed or modulated signals can also be measured by NVNAs. This is particularly important for nonlinear devices such SOS-MOSFET or GaN HEMTs which are affected by various low-frequency memory effects such as parasitic bipolar junction transistor effects, self-heating, and cyclo-stationary charging of traps. Recent techniques reported for low-duty rate pulsed and modulated RF NVNA measurements will then be reviewed to shine new light in the time-varying response of transistors excited by high peak to average power ratio (PAPR) modulated signals.
The chemical composition of the aerial parts essential oil of Ammi crinitum Guss. (Apiaceae) endemic of Sicily (Italy)
Creators: name: D’Agostino, Giulia
name: Cicio, Adele
name: Vaglica, Alessandro
name: Ilardi, Vincenzo
name: Bruno, Maurizio
Publisher: name: Taylor & Francis
Year: 2022
Subjects: subject: Genetics
subject: FOS: Biological sciences
subject: Environmental Sciences not elsewhere classified
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: Biological Sciences not elsewhere classified
subject: Plant Biology

description: Ammi L. is a small genus of economically important plants belonging to Apiaceae family that includes only six taxa. In the present study the chemical composition of the essential oil from aerial parts of Ammi crinitum Guss., a very rare plant, endemic of Sicily, was analyzed by GC–MS. No previously paper has been published on this species. The results showed the presence of large quantity of monoterpene hydrocarbons with sabinene (63.9%), as the most abundant component. Other metabolites present in good quantity were γ-terpinene (8.0%), and 4-terpineol (3.7%). Based on the composition of the essential oil of all the other Ammi taxa, several considerations have been carried out.
Microwave Spectroscopy for non Invasive Biological and Health Sensing Slides
Creators: Katia Grenier
Publisher: name: IEEE
Year: 2017

MTT Webinar Slides
Microwave and millimeter wave dielectric spectroscopy is a powerful technique to perform a non-ionizing and non-destructive characterization of materials. In the case of biological and health sensing, the analyzing technique benefits from different appealing features. First, the dielectric relaxation phenomenon of the water molecules is located in the microwave range (around 20 GHz), and these molecules are the major constituent of the living and involve in many biological processes. Additionally, the electromagnetic fields in this frequency range penetrates beyond the capacitive bi-lipid cytoplasmic membrane of cells and consequently opens the door to intracellular investigations. Finally, the microwave band for the dielectric spectroscopy also enables the measurements of living cells directly into their culture medium, without tremendous losses induced by the rich ionic and nutrients content of the surrounding fluid. Therefore, the development of microwave dielectric spectroscopy for the analysis of the living at the molecular and cellular levels notably is very attractive for biological researches and biomedical applications, where non-invasivity, label-free and contact-less abilities as well as in-liquid measurements constitute important leitmotivs.  The talk will consequently start with the motivations of developing such a sensing technique. After a reminder on the interaction of electromagnetic fields with the matter, miniature biosensors and associated techniques, which have been developed to characterize different biological materials in aqueous solution, will be presented. Issues in terms of living constraints, broadband and narrow band measurements, sensitivity, specificity and repeatability of measurements with standard deviations will notably be highlighted on different biomaterials, such as carbohydrates and amino acids for biomolecules, as well as human cells in suspension and at the single cell level. The interest of the technique will also be spatially extended toward the rapid and non-invasive analysis of tissues on animals, as well as demonstrated for the monitoring of complex biological processes.
Synthesis of ring-A modified lupeol derivatives and their anti-proliferative activity: identification of potent lead active against MCF-7 breast cancer cells
Creators: name: Narendar, Kummari
name: Chander, Punnam Mandha
name: Eedara, Chowdary Abhisheik
name: Andugulapati, Sai Balaji
name: Ramalingam, Vaikundamoorthy
name: SureshBabu, K.
name: Vijayachari, P.
Publisher: name: Taylor & Francis
Year: 2022
Subjects: subject: Biochemistry
subject: Cell Biology
subject: Pharmacology
subject: Biotechnology
subject: Chemical Sciences not elsewhere classified
subject: Immunology
subject: FOS: Clinical medicine
subject: Biological Sciences not elsewhere classified
subject: Developmental Biology
subject: Cancer
subject: Hematology

description: In continuation of our research program aimed at the development of new natural product-based anticancer agents, a series of lupeol derivatives (5a-5k and 6a-6i) were prepared with the introduction of aryl functionalities and amino acids at C-3 position. All the synthesised derivatives were assessed for in vitro anticancer activity against four human cancer cell lines using MTT assay. Interestingly, the compounds 5j, 5k, and 6 g showed potent activity against MCF7 cells as compared with the parent compound. Further, the flowcytometry analysis revealed that the 5j,5k, and 6 g arrest the cells at the G2/M phase and induce the early apoptosis in MCF7 cells. In addition, the selected compounds inhibit the BcL2 expression and increase the Bax protein expression in MCF7 cells. Overall, these results indicated that the lupeol derivatives could serve as a promising launch point for the development of anticancer agents.
Global Weather Observations from a Science Quality Millimeter Wave Atmospheric Sounding Radiometer on a 6U CubeSat Slides
Creators: Steven Reising
Publisher: name: IEEE
Year: 2018

MTT Webinar Slides
Global observations of clouds and precipitation processes are essential to improve monitoring and prediction of tropical cyclones and severe storms with substantial impacts on human life and property.  Convection plays an important role in influencing global weather patterns, as well as distributing fresh water and producing severe weather conditions.  However, fundamental gaps in understanding remain, prompting the 2017 Earth Science Decadal Survey to state one of its “most important” science questions as, “Why do convective storms, heavy precipitation, and clouds occur exactly when and where they do?”
To improve understanding of cloud and precipitation processes, rapid revisit global observations are necessary.  Geostationary satellites provide visible and infrared weather observations with temporal resolution of approximately a few minutes.  However, improving understanding of the life cycle of convection requires fine time-resolution microwave radiometric observations that penetrate deep inside storms where precipitation processes occur.
To address this critical need for observations, the Temporal Experiment for Storms and Tropical Systems (TEMPEST) mission deploys a train of up to eight 6U CubeSats with identical low-mass, low-power millimeter-wave radiometers observing at five frequencies from 87 to 181 GHz.  The TEMPEST train samples rapid changes in the life cycle of convection by observing every 3-4 minutes for up to 30 minutes.  TEMPEST fills a critical observational gap and complements existing and future satellite missions.
To demonstrate a global microwave atmospheric sounder on a 6U CubeSat, the TEMPEST Demonstration (TEMPEST-D) satellite was launched to the ISS on May 21, 2018 and successfully deployed from the ISS on July 13, 2018, from an initial orbit with 400-km altitude and 51.6° inclination.   TEMPEST-D met its mission requirements in the first 90 days and continues to provide weather observations for more than 11 months.  Comparison of on-orbit measurements with four reference sensors indicate that TEMPEST-D is a very well-calibrated and stable radiometer with low noise, rivaling that of much larger and more expensive operational instruments.
Remodeling of occluded internal carotid artery in vessel wall magnetic resonance imaging
Creators: name: Zhou, Jun
name: Cai, Shi-Feng
name: Yuan, Xian-Shun
name: Pang, Zai-Ying
name: Yu, Bing-Xin
name: Yao, Hong
name: Xu, Jing-Jing
name: Pang, Yue-Jiu
name: Guo, Ning
name: Liu, Xue-Ping
Publisher: name: Taylor & Francis
Year: 2020
Subjects: subject: Space Science
subject: Medicine
subject: Cell Biology
subject: Physiology
subject: FOS: Biological sciences
subject: Immunology
subject: FOS: Clinical medicine
subject: Biological Sciences not elsewhere classified
subject: Developmental Biology

description: The purpose of the present study was to investigate the remodeling pattern of the extracranial occluded internal carotid artery (OICA) by vessel wall magnetic resonance imaging (VWI). Thirty-nine atherosclerotic OICAs from 32 consecutive cases underwent 3-Tesla VWI to acquire pre- and post-contrast T1-weighted two-dimensional fluid-attenuated inversion recovery fast spin echo sequences. 25 symptomatic CAs exhibited ipsilateral downstream cerebral ischemia or ophthalmic artery embolism within last three months. The 14 remaining CAs were asymptomatic. Twenty-four CAs from 22 patients with atherosclerosis but no stenosis were recruited as control group. The outer wall area (OWA) was calculated based on the outer contour of the carotid artery drawn on the pre-contrast VWI. Negative remodeling was defined as a lower OWA compared to that of control group. Clinical characteristics including age, sex and vascular risk factors showed no significant difference between the occluded and control group. However, the OWA was lower in the occluded group than in the control group (0.63 versus 0.90 cm2, p = 0.004). For all OICAs, the OWA was larger in symptomatic cases than asymptomatic cases (0.71 versus 0.49cm2, p = 0.025). Using a cutoff value of 0.44, the sensitivity and specificity of OWA for detecting symptomatic OICA were 0.88 and 0.57, respectively. Heterogeneous signal intensity and enhancement were more often observed at the proximal than the distal segment of occlusion (p < 0.001). The inter-observer agreement regarding the evaluation of VWI characteristics was desirable (κ = 0.805 ∼ 0.847). Negative remodeling is prevalent in OICA, especially in asymptomatic cases.
Marks of heliacal rising of Sirius on the sundial of the Bronze Age
Creators: name: Vodolazhskaya Larisa, N.
name: Usachuk Anatoliy, N.
name: Nevsky Mikhail Yu.
Publisher: name: Archaeoastronomy and Ancient Technologies
Year: 2015
Subjects: СОСУД
VESSEL
COROLLA
MARKS
СОЛНЕЧНЫЕ ЧАСЫ
SUNDIAL
ГНОМОН
GNOMON
СРУБНАЯ КУЛЬТУРА
SRUBNA CULTURE
HELIACAL RISING
СИРИУС
SIRIUS
ARCHAEOASTRONOMY
ВЕНЧИК
МЕТКИ
ГЕЛИАКИЧЕСКИЙ ВОСХОД

description: The article presents the results of interdisciplinary research made with the help of archaeological, physical and astronomical methods. The aim of the study were analysis and interpretation corolla marks of the vessel of the Late Bronze Age, belonging to Srubna culture and which was found near the Staropetrovsky village in the northeast of the Donetsk region. Performed calculations and measurements revealed that the marks on the corolla of Staropetrovsky vessel are marking of horizontal sundial with a sloping gnomon. Several marks on the corolla of the vessel have star shape. Astronomical calculations show that their position on the corolla, as on "dial" of watch, indicates the time of qualitative change the visibility of Sirius in the day its heliacal rising and the next few days in the Late Bronze Age at the latitude of detection of Staropetrovsky vessel. Published in the article the results of astronomical calculations allow to state that astronomical year in the Srubna tradition began with a day of heliacal rising of Sirius.