bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Generalized Essential Matrix Correction: An Efficient Solution to the Problem and Its Applications
Authors: Miraldo Pedro , Cardoso João R.
Published: June 2020

This paper addresses the problem of finding the closest generalized essential matrix from a given$$6\times 6$$6×6matrix, with respect to the Frobenius norm. To the best of our knowledge, this nonlinear constrained optimization problem has not been addressed in the literature yet. Although it can be solved directly, it involves a large number of constraints, and any optimization method to solve it would require much computational effort. We start by deriving a couple of unconstrained formulations of the problem. After that, we convert the original problem into a new one, involving only orthogonal constraints, and propose an efficient algorithm of steepest descent type to find its solution. To test the algorithms, we evaluate the methods with synthetic data and conclude that the proposed steepest descent-type approach is much faster than the direct application of general optimization techniques to the original formulation with 33 constraints and to the unconstrained ones. To further motivate the relevance of our method, we apply it in two pose problems (relative and absolute) using synthetic and real data.
Fast character modeling with sketch-based PDE surfaces
Authors: You Lihua , Yang Xiaosong , Pan Junjun , Lee Tong-Yee , Bian Shaojun , Qian Kun , Habib Zulfiqar , Sargano Allah Bux , Kazmi Ismail , Zhang Jian J.
Published: June 2020

Virtual characters are 3D geometric models of characters. They have a lot of applications in multimedia. In this paper, we propose a new physics-based deformation method and efficient character modelling framework for creation of detailed 3D virtual character models. Our proposed physics-based deformation method uses PDE surfaces. Here PDE is the abbreviation of Partial Differential Equation, and PDE surfaces are defined as sculpting force-driven shape representations of interpolation surfaces. Interpolation surfaces are obtained by interpolating key cross-section profile curves and the sculpting force-driven shape representation uses an analytical solution to a vector-valued partial differential equation involving sculpting forces to quickly obtain deformed shapes. Our proposed character modelling framework consists of global modeling and local modeling. The global modeling is also called model building, which is a process of creating a whole character model quickly with sketch-guided and template-based modeling techniques. The local modeling produces local details efficiently to improve the realism of the created character model with four shape manipulation techniques. The sketch-guided global modeling generates a character model from three different levels of sketched profile curves called primary, secondary and key cross-section curves in three orthographic views. The template-based global modeling obtains a new character model by deforming a template model to match the three different levels of profile curves. Four shape manipulation techniques for local modeling are investigated and integrated into the new modelling framework. They include: partial differential equation-based shape manipulation, generalized elliptic curve-driven shape manipulation, sketch assisted shape manipulation, and template-based shape manipulation. These new local modeling techniques have both global and local shape control functions and are efficient in local shape manipulation. The final character models are represented with a collection of surfaces, which are modeled with two types of geometric entities: generalized elliptic curves (GECs) and partial differential equation-based surfaces. Our experiments indicate that the proposed modeling approach can build detailed and realistic character models easily and quickly.
Repeat radiation with bevacizumab and minocycline in bevacizumab-refractory high grade gliomas: a prospective phase 1 trial
Authors: Cohen Adam L. , Anker Christopher J. , Johnson Brett , Burt Lindsay M. , Shrieve Dennis C. , Salzman Karen , Jensen Randy , Boucher Ken , Colman Howard
Published: June 2020

Introduction

There are no effective treatments for gliomas after progression on radiation, temozolomide, and bevacizumab. Microglia activation may be involved in radiation resistance and can be inhibited by the brain penetrating antibiotic minocycline. In this phase 1 trial, we examined the safety and effect on survival, symptom burden, and neurocognitive function of reirradiation, minocycline, and bevacizumab.

Methods

The trial used a 3 + 3 design for dose escalation followed by a ten person dose expansion. Patients received reirradiation with dosing based on radiation oncologist judgment, bevacizumab 10 mg/kg IV every two weeks, and oral minocycline twice a day. Symptom burden was measured using MDASI-BT. Neurocognitive function was measured using the COGSTATE battery.

Results

The maximum tolerated dose of minocycline was 400 mg twice a day with no unexpected toxicities. The PFS3 was 64.6%, and median overall survival was 6.4 months. Symptom burden and neurocognitive function did not decline in the interval between treatment completion and tumor progression.

Conclusions

Minocycline 400 mg orally twice a day with bevacizumab and reirradiation is well tolerated by physician and patient reported outcomes in people with gliomas that progress on bevacizumab.
Investigating exploration for deep reinforcement learning of concentric tube robot control
Authors: Iyengar Keshav , Dwyer George , Stoyanov Danail
Published: June 2020

Purpose

Concentric tube robots are composed of multiple concentric, pre-curved, super-elastic, telescopic tubes that are compliant and have a small diameter suitable for interventions that must be minimally invasive like fetal surgery. Combinations of rotation and extension of the tubes can alter the robot’s shape but the inverse kinematics are complex to model due to the challenge of incorporating friction and other tube interactions or manufacturing imperfections. We propose a model-free reinforcement learning approach to form the inverse kinematics solution and directly obtain a control policy.

Method

Three exploration strategies are shown for deep deterministic policy gradient with hindsight experience replay for concentric tube robots in simulation environments. The aim is to overcome the joint to Cartesian sampling bias and be scalable with the number of robotic tubes. To compare strategies, evaluation of the trained policy network to selected Cartesian goals and associated errors are analyzed. The learned control policy is demonstrated with trajectory following tasks.

Results

Separation of extension and rotation joints for Gaussian exploration is required to overcome Cartesian sampling bias. Parameter noise and Ornstein–Uhlenbeck were found to be optimal strategies with less than 1 mm error in all simulation environments. Various trajectories can be followed with the optimal exploration strategy learned policy at high joint extension values. Our inverse kinematics solver in evaluation has 0.44 mm extension and$$0.3^{\circ }$$0.3∘rotation error.

Conclusion

We demonstrate the feasibility of effective model-free control for concentric tube robots. Directly using the control policy, arbitrary trajectories can be followed and this is an important step towards overcoming the challenge of concentric tube robot control for clinical use in minimally invasive interventions.
Satisfied or not? Exploring the interplay of individual, country and international organization characteristics for negotiation success
Authors: Panke Diana , Polat Gurur , Hohlstein Franziska
Published: June 2020

International norms and rules are created in international negotiations. A comprehensive survey shows that the satisfaction with negotiation outcomes varies between delegates, states and International Organizations (IOs), which is important as it has potential ramifications for state compliance and the effectiveness of the international rules and norms. This paper investigates which role individual, country and IO features and their interactions play for satisfaction with international negotiation outcomes. Drawing on approaches of international negotiation and cooperation, hypotheses on individual, country and IO features are specified and examined empirically with a multilevel analysis. This reveals that especially individual and IO level features impact outcome satisfaction. Outcome satisfaction increases if delegates put in much work in negotiations and can conduct them flexibly and if IOs are small in size, and have institutional designs that seek to foster debates. The paper also shows that there are cross-level interaction effects. Most notably, the positive effect of flexibility on high outcome satisfaction is less pronounced when negotiations are more strongly characterized by bargaining dynamics. Vice-versa, when IOs are prone to arguing dynamics all actors become more satisfied.
Intrinsic values and the life framework of values: why we should go back to basics—comment to O’Connor and Kenter (2019)
Authors: Neuteleers Stijn , Deliège Glenn , Melle Ullrich
Published: June 2020

The IPBES Framework aims to allow room for a plurality of values and recently proposed a move from `Ecosystem Services’ to `Nature’s Contributions to People’. O’Connor and Kenter (2019) argue that both approaches still disregard nature as an end in itself. Therefore, they propose a new conceptualisation of `intrinsic value’ and a new approach, labelled the `Life Framework of Values’. This work is highly relevant, but we argue that there are some fundamental conceptual problems with their current account, in particular with the conceptualisation of intrinsic value, relational value, and their category of `living as’. We argue that the changes made to the underlying framework of O’Neill add more confusion than clarification, that it is better to return to the original framework and to focus energy on making that framework applicable.
Does Mixed Neuroendocrine-Nonneuroendocrine Neoplasm (MiNEN) of the Parathyroid Gland Exist? First Description of a Possible Case
Authors: Di Palma Silvana , Mufaddal Moonim , Iyer Vishwas , Sciarra Amedeo , La Rosa Stefano
Published: June 2020

We describe the histological, histochemical, and immunohistochemical features of an unusual neoplasm of the parathyroid gland showing the histologic criteria of a mixed neuroendocrine-nonneuroendocrine neoplasm (MiNEN). To the best of our knowledge, this is the first report of such a tumor. A 43-year old male presented with acute and severe abdominal pain due to acute pancreatitis. On physical examination a painless lump in the right neck was detected and laboratory analyses revealed hyperparathyroidism (parathormone: 146 pmol/L, normal range 1.05–6.83) and hypercalcemia (calcium level: 3.02 mg/dL, normal range 2.25–2.5), which fell to 2.55 mg/dL after parathyroidectomy. Histologically, the tumor was a parathyroid carcinoma associated with a mucous secreting adenocarcinoma also confirmed by histochemical (Alcian blue—periodic acid Schiff) and immunohistochemical stainings. The present case expands the spectrum of MiNENs that can be found in endocrine organs.
Downstream processing and characterization of polyhydroxyalkanoates (PHAs) produced by mixed microbial culture (MMC) and organic urban waste as substrate
Authors: Lorini Laura , Martinelli Andrea , Pavan Paolo , Majone Mauro , Valentino Francesco
Published: June 2020

The utilization of food waste and sewage sludge as organic substrate from urban context for the synthesis of microbial polyhydroxyalkanoates (PHAs) has been only recently investigated at pilot scale. Within this context, two stabilization methods have been found for preserving the amount of PHA intracellularly produced by open mixed microbial culture (MMC): thermal drying and wet acidification of the biomass at the end of PHA accumulation process. The extracted PHA from the two differently stabilized biomasses was then characterized with regard to chemical composition, molecular weight, and thermal properties. The polymer contained two types of monomers, namely 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) at a relative percentage of 93.0–79.8 and 7.0–20.2 w/w, respectively. PHA extracted from wet-acidified biomass had higher average molecular weights (Mw) of 370–424 kDa while PHA recovered from thermally stabilized dried biomass had a 3-fold lower Mw (on average). The PHA decomposition temperatures Td10% and Tdmax were in the range 260–268 °C and 269–303 °C, respectively, not dependent on the monomeric composition or molecular weight. Thermal properties such as melting temperature (Tm1 132–150 °C; Tm2 155–167 °C) and melting enthalpy (26–70 J/g) were quantified in a relatively broad range according to the different stabilization-extraction method and obtained composition.
Two-level fusion big data compression and reconstruction framework combining second-generation wavelet and lossless compression
Authors: Chuanchao Zhang
Published: June 2020

In view of the characteristics of big data, fuzziness, and real time of data acquisition and transmission in the fuzzy information system faced by aircraft health management, to reduce the load of airborne data processing and transmission system under the condition of limited airborne computing resources and strong time constraints, the data collected by the airborne system are first compressed, and the amount of data are reduced before transmission and reconstructed after transmission. In view of the situation that the compression ratio of primary data compression is too small and the compression time is too long for large-scale fuzzy systems to meet the transmission requirements of the system, this paper combines the advantages of lossy compression method which consumes less time and lossless compression method which has higher compression ratio, and innovatively proposes a two-level data compression and reconstruction framework combining lossy compression and lossless compression. The optimization analysis is carried out. Taking a real aero-engine health sample as an example, the validity, scientificity, and robustness of the proposed framework are verified by comparing with data compression and reconstruction algorithm based on redundant sparse representation and compressed sensing.
Electrocochleography in cochlear implantation: Development, applications, and future directions
Authors: Barnes Jason H. , Yin Linda X. , Saoji Aniket A. , Carlson Matthew L.
Published: June 2020

Electrocochleography (ECochG) is an electrophysiological technique that records electrical potentials generated by different components of the inner ear and peripheral cochlear nerve in response to acoustic stimulation. ECochG responses can be analyzed into (1) cochlear microphonics (CM), (2) auditory nerve neurophonics, (3) summating potential, and (4) compound action potential. Over the past few decades, there have been ongoing refinements in technique and updates in the understanding of recorded potentials. Historically, ECochG found its main application in the diagnostic evaluation of Meniere's disease (MD). However, in the last decade, the focus has shifted towards cochlear implantation (CI). In patients with residual hearing after CI, combined electric and acoustic stimulation has resulted in improved hearing and speech outcomes. Despite efforts to mitigate trauma during electrode insertion, hearing preservation rates vary after surgery. During implantation, real‐time ECochG offers an opportunity to measure frequency specific CMs elicited from a localized region in the cochlea as the surgeon inserts the electrode array. In extracochlear ECochG recordings, the recording electrode can be placed on the promontory, the stapes, or the tympanic membrane. Intracochlear ECochG can be performed by inserting a recording electrode into the cochlea or by using one of the CI electrodes as the recording electrode. The loss of intraoperative ECochG signal may indicate cochlear trauma from electrode insertion, but the association between intraoperative ECochG changes and cochlear trauma remains controversial. The ability to monitor cochlear trauma during CI electrode placement holds promise to improve hearing preservation outcomes, modify surgical techniques, and change electrode design. The goal of this review is to provide a comprehensive overview of the electrophysiology and history of ECochG, discuss its recent applications in CI, and explore the ongoing research in this expanding field.
Assessment of race and sex as risk factors for colonization with multidrug-resistant organisms in six nursing homes
Authors: Gontjes Kyle J. , Gibson Kristen E. , Lansing Bonnie J. , Mody Lona , Cassone Marco
Published: June 2020

The role of demographic characteristics, such as sex and race, as risk factors for colonization with multidrug-resistant organisms, has not been established in the nursing home setting. We demonstrate significantly higher prevalence overall in male patients, and sex differences are dependent on organism of interest and body site.
Aristotle's Manipulative Maxims
Authors: DiLeo Daniel
Published: June 2020

In actual regimes as described by Aristotle, authoritative civic choices were not the outcome of speech among citizens about the noble things and the just things. Rather, he saw them as products of the flawed presuppositions and misperceptions of dominant factions. Since he held that the human good was dependent on the persistence of lawful systems of rule, no matter how flawed, he viewed the tendency of dominant factions toward regime-destructive extremism as the fundamental political problem. His short-term response was to teach manipulative rhetoric and the outline of a strategy for regime preservation to his students. This equipped his students to prevail against the speech of the ignorant and malevolent and impressed those students with the need to acquire political knowledge. His long-term response was the initiation of a system of education that would turn citizens away from regime-destructive predilections.
Ultra-faint Lyman Alpha Emitters with MUSE
Authors: Maseda Michael V. ,   the MUSE GTO Consortium
Published: June 2020

Using an ultra-deep, untargeted survey with the MUSE integral field spectrograph on the ESO Very Large Telescope, we obtain spectroscopic redshifts to a depth never explored before: galaxies with observed magnitudes m > 30–32. Specifically, we detect objects via Lyman-α emission at 2.9 < z < 6.7 without individual continuum counterparts in areas covered by the deepest optical/near-infrared imaging taken by the Hubble Space Telescope, the Hubble Ultra Deep Field. In total, we find more than 100 such objects in 9 square arcminutes at these redshifts, also including a number of sources that are visible only in the HST band that contains Lyman-α. Detailed HST and IRAC stacking analyses confirm the Lyman-α emission as well as the 1216 Å breaks, faint UV continua (MUV ∼ −15), and optical emission lines: these objects are the faintest spectroscopically-confirmed galaxies at high-z. The blue UV continuum slopes and measurements/limits on the equivalent widths of Lyman-α, which in some cases exceeds 300 Å, are consistent with ages < 10 Myr, metallicities < 5% solar, and stellar masses < 107–8 solar masses. The nature of these types of objects is intriguing as they could be the faint star-forming sources of Reionization and could represent the initial (strong) phase of stellar mass growth in galaxies.
Guitarra, a Simulator for the JWST/NIRCam
Authors: Willmer Christopher N. A. , Hainline Kevin N. , Curtis-Lake Emma ,   JADES Team
Published: June 2020

We present an overview of Guitarra, a simulator for the Near Infrared Camera that creates scenes from catalogues of mock or real sources using the current best estimates of the instrument characteristics and the pattern on the sky of the observations.
Galaxy Evolution through spectral fitting tools: A comparative study between STECKMAP and FADO
Authors: Pappalardo Ciro , Papaderos Polychronis , Gomes Jean Michel , Cardoso Leandro , Afonso Ana , Matute Israel , Amarantidis Stergios
Published: June 2020

Spectral analysis is nowadays a widely used tool to investigate the evolution of galaxies. Assessing the reliability of this approach is crucia, motivating a through analysis. In this poster, a comparative study between two widely tools, FADO and STECKMAP, is performed, focusing on the discrepancies between the different approaches. Both codes use different methods to extract the best fit, allowing the possibility to disentangle possible biases introduced in the analysis. Our analysis showed that where nebular emission is not negligible, the results obtained with methods taking into account such a component are more reliable, and this can be very important when moving at higher redshift, where stellar populations are younger. In particular, this is true for starburst systems, where a huge amount of stars are forming almost at the same epoch. This is an important aspect to take into account the future survey, as JWST for example, which will provide the community with medium resolution spectra of galaxies at redshift 3-4 and even higher.
The quest for relics: Massive compact galaxies in the local Universe
Authors: Schnorr-Müller A. , Trevisan M. , Lohmann F. S. , Mallmann N. , Riffel R. , Chies-Santos A. , Furlanetto C.
Published: June 2020

In the local Universe there exists a rare population of compact galaxies resembling the high-redshift quiescent population in mass and size. It has been found that some of these objects have survived largely unchanged since their formation at high-z. They are called relic galaxies. With the goal of finding relic galaxies, we searched the SDSS-MaNGA DR15 release for massive compact galaxies. We find that massive compact galaxies are mostly composed of old, metal-rich and alpha enhanced stellar populations. In terms of kinematics, massive compact galaxies show ordered rotation in their velocity fields and σ* profiles rising towards the center. They are predominantly fast rotators and show increased rotational support when compared to a mass-matched control sample of average-sized early-type galaxies. These properties are consistent with these objects being relic galaxies. However, to confirm their relic status, we need to probe larger radii (⪎3Re) than probed with the current data.
Catching Elves in Argentina
Authors: Merenda Kevin-Druis , Mussa Roberto , Wiencke Lawrence
Published: June 2020

The world’s largest cosmic ray detector accidentally spotted elves, an unusual lightning phenomenon high in the atmosphere. Now it’s intentionally looking for more.
This Week: The Best of Eos
Authors:   AGU
Published: June 2020

As we head into the second half of 2020, we take a look back on our favorite stories of the year so far.
Synthesis of cube–rod–tube triblock asymmetric nanostructures for enhanced heterogeneous catalysis
Authors: Hu Wenli , Liu Chao , Wang Jing , Pei Congcong , Zhang Ye , Zhang Chaoqi , Liu Yang , Shan Yongkui , Yu Chengzhong
Published: June 2020

A triblock asymmetric nanostructure is fabricated via a sequential growth process, which can be used as an active nano stir bar with accelerated catalytic performance.
The copper(ii)-catalyzed and oxidant-promoted regioselective C-2 difluoromethylation of indoles and pyrroles
Authors: Zhang Dong , Fang Zheng , Cai Jinlin , Liu Chengkou , He Wei , Duan Jindian , Qin Ning , Yang Zhao , Guo Kai
Published: June 2020

A novel and efficient approach for the highly selective C-2 difluoromethylation of indole derivatives was developed by using sodium difluoromethylsulfinate (HCF2SO2Na) as the source of difluoromethyl groups and a Cu(ii) complex as the catalyst.
Bacteria encapsulation and rapid antibiotic susceptibility test using a microfluidic microwell device integrating surface-enhanced Raman scattering
Authors: Huang Hsiu-Kang , Cheng Ho-Wen , Liao Cheng-Chieh , Lin Shang-Jyun , Chen Yi-Zih , Wang Juen-Kai , Wang Yuh-Lin , Huang Nien-Tsu
Published: June 2020

We developed a microfluidic microwell device integrating SERS substrate for an efficient bacteria encapsulation and enrichment followed by in situ SERS-AST measurement, which can potentially apply for high throughput and multi-parallel AST.
Ultrasound-responsive alkaline nanorobots for the treatment of lactic acidosis-mediated doxorubicin resistance
Authors: Meng Xia , Xu Yurui , Lu Qiangbing , Sun Lei , An Xueying , Zhang Jikang , Chen Jianmei , Gao Ya , Zhang Yu , Ning Xinghai
Published: June 2020

Lactic acidosis is one of the key characteristics of the tumor microenvironment (TME), and plays a critical role in therapy resistance, making it an attractive target for enhancing anticancer treatment.
Emerging memory devices for artificial synapses
Authors: Park Youngjun , Kim Min-Kyu , Lee Jang-Sik
Published: June 2020

This paper reviews recent developments in artificial synapses that exploit various emerging memory devices. The emulation of synaptic plasticity and operation mechanism of artificial synapses using various materials and structures are presented.
The mechanobiology of kidney podocytes in health and disease
Authors: Reynolds Paul A.
Published: June 2020

Chronic kidney disease (CKD) substantially reduces quality of life and leads to premature death for thousands of people each year. Dialysis and kidney organ transplants remain prevalent therapeutic avenues but carry significant medical, economic and social burden. Podocytes are responsible for blood filtration selectivity in the kidney, where they extend a network of foot processes (FPs) from their cell bodies which surround endothelial cells and interdigitate with those on neighbouring podocytes to form narrow slit diaphragms (SDs). During aging, some podocytes are lost naturally but accelerated podocyte loss is a hallmark of CKD. Insights into the origin of degenerative podocyte loss will help answer important questions about kidney function and lead to substantial health benefits. Here, approaches that uncover insights into podocyte mechanobiology are reviewed, both those that interrogate the biophysical properties of podocytes and how the external physical environment affects podocyte behaviour, and also those that interrogate the biophysical effects that podocytes exert on their surroundings.
Microtubules pull the strings: disordered sequences as efficient couplers of microtubule-generated force
Authors: Volkov Vladimir A.
Published: June 2020

Microtubules are dynamic polymers that grow and shrink through addition or loss of tubulin subunits at their ends. Microtubule ends generate mechanical force that moves chromosomes and cellular organelles, and provides mechanical tension. Recent literature describes a number of proteins and protein complexes that couple dynamics of microtubule ends to movements of their cellular cargoes. These ‘couplers’ are quite diverse in their microtubule-binding domains (MTBDs), while sharing similarity in function, but a systematic understanding of the principles underlying their activity is missing. Here, I review various types of microtubule couplers, focusing on their essential activities: ability to follow microtubule ends and capture microtubule-generated force. Most of the couplers require presence of unstructured positively charged sequences and multivalency in their microtubule-binding sites to efficiently convert the microtubule-generated force into useful connection to a cargo. An overview of the microtubule features supporting end-tracking and force-coupling, and the experimental methods to assess force-coupling properties is also provided.
Robust particle filter algorithms for one‐step randomly delayed measurements and heavy‐tailed noise
Authors: Wang Zongyuan , Zhou Weidong
Published: June 2020

The development of particle filters for emerging data transmission applications is essential to address network‐related issues. In this Letter, a robust particle filter algorithm for non‐linear systems with one‐step randomly delayed measurements and outlier corrupted measurement noise is investigated. To address the issue of measurement outliers, a Student's‐t distribution is utilised to model the measurement noise. For the random delay uncertainties, a Bernoulli random variable is employed, based on which the likelihood function is transformed into an exponential multiplication form. The filter state estimation is obtained by Bayes's theorem and using variational Bayesian approach, the latent random variables and Bernoulli random variable are estimated together. The superior performance of the proposed method is verified through a typical example by comparison with existing particle filters that consider random measurement delay or heavy‐tailed measurement noise.
Controllable reactor based hybrid HVDC breaker
Authors: Heidary Amir , Bigdeli Mehdi , Rouzbehi Kumars
Published: June 2020

Short circuit fault occurrence in high‐voltage DC (HVDC) systems causes extremely high currents in a fast raising time that does not experience current zero‐crossing. To protect HVDC systems/grids against fault current, fast HVDC breaker is an essential equipment. This study presents the design procedure of a novel HVDC breaker based on solid‐state controllable reactor which is able to reduce the fault current's rate of rise and fault current amplitude to less than grid nominal current in the breaking process. The main achievement of the proposed HVDC breaker is that not only breaker does not encounter fault current, but also none of the series HVDC equipment is influenced by the fault. The designed breaker performance is studied by PSCAD/EMTPS, and then the simulation results are validated by the developed laboratory experimental setup.
Reviews on sulphur corrosion phenomenon of the oil–paper insulating system in mineral oil transformer
Authors: Cong Haoxi , Pan Hao , Qian Danyang , Zhao Haiyu , Li Qingmin
Published: June 2020

The active sulphur compounds in transformer oil would react with copper wires and produce cuprous sulphides, which then attach themselves to the surface of copper wires and insulating paper, thus reducing the electrical performance of oil–paper insulation and causing insulation failure. This article aims to make a comprehensive summary on the field of sulphur corrosion of oil–paper insulation in the mineral oil transformer, including the corrosion mechanism of sulphide on copper sheets, the deterioration mechanism of sulphide on oil–paper, the factors influencing sulphur corrosion reaction, the method of characterising the degree of sulphur corrosion, the protection technology of sulphur corrosion and the field operation measures for sulphur corrosion. Moreover, four key problems that need to be further solved were sorted out: the synergistic deterioration mechanism of sulphide and its transformation mechanism, the micro‐process and forming path of sulphur corrosion reaction, the characteristic parameters and quantitative characterisation methods of sulphur corrosion degree, and the effective protection technology of sulphide corrosion. To solve these problems, efforts will be made for deeper understanding of the sulphur corrosion phenomenon and its deterioration mechanism based on theoretical background, the assessment methods and protection technology, endeavouring to put forward solid theoretical basis and feasible technical means for preventing sulphur corrosion insulation failure.
Evaluation of nano‐filler dispersion quality in polymeric films with binary feature characteristics and fractal analysis
Authors: Yildiz Kazim , Yildiz Zehra
Published: June 2020

This study investigates the use of binary features and fractal dimension analysis to evaluate the dispersion quality of nanofillers in thin polymeric films by using light microscopy images. For this purpose, polymeric films were cast with the inclusion of various montmorillonite (MMT) nanofiller amounts. Then the light microscopy images were captured from the polymeric films then preprocessed for the evaluation. Thresholding process was applied to the obtained images for each nanofiller percentage level. The obtained binary level images were used in the feature extraction process with binary statistics and fractal dimension. Thermogravimetric analysis (TGA) was used to evaluate the flame resist behaviour of polymeric films based on the dispersion quality of nanofillers. The samples with various nanofiller contents were tested using the image processing method and the results were all compared with the TGA results. The results obtained by the feature extraction process and TGA, about the dispersion quality of nanofillers, were all in good agreement.
DQ impedance‐decoupled network model‐based stability analysis of offshore wind power plant under weak grid conditions
Authors: Zhou Weihua , Torres‐Olguin Raymundo E. , Wang Yanbo , Chen Zhe
Published: June 2020

This study presents a dq impedance‐decoupled network modelling method of offshore wind power plant (OWPP) for stability analysis. DQ impedance frequency responses of grid‐connected inverters (GCIs) and long transmission cables (LTCs) are first measured by frequency scanning method, which are fitted as transfer function matrices using matrix fitting algorithm. Then, the GCIs are modelled as Norton equivalent circuits. In addition, per‐unit‐length electrical parameters of the LTCs are extracted from the measured dq impedance frequency responses of a specific LTC, based on which dq impedance‐decoupled two port network models of the LTCs are established. DQ impedance‐decoupled network model of the whole OWPP is then established based on connection relationships of these GCIs and LTCs. Finally, generalised Nyquist criterion (GNC) is performed in all the dq impedance‐decoupled subsystems, and the subsystems where the GNC is not satisfied are identified as instability sources. Compared with conventional impedance‐based stability analysis methods of OWPP, the proposed dq impedance‐decoupled modelling method is able to facilitate the application of GNC and further instability source identification based on partitioning the whole OWPP into several decoupled subsystems. The effectiveness of the network modelling method is validated based on time‐domain simulation results in Matlab/Simulink and real‐time verification results in OPAL‐RT.
Simple discontinuous PWM strategies to reduce the switching losses of an indirect matrix converter
Authors: Patel Payal , Mulla Mahmadasraf A.
Published: June 2020

This work proposes the new discontinuous pulse width modulation (DPWM) schemes for an indirect matrix converter (IMC) to reduce the switching losses. The use of discontinuous modulation signals reduces the switching losses of the IMC by reducing the switching counts per cycle of the output converter. The key feature of the proposed schemes is the easy implementation as compared to existing DPWM schemes of the IMC. The major drawback of the existing DPWM schemes is the absence of zero current commutation (ZCC). In the absence of ZCC, the switchings of the input converter are accomplished through four‐step commutation which adds the difficulties to the implementation. The proposed scheme overcomes above limitation by using the triangular carrier instead of the sawtooth carrier for the modulation of input converter. Consequently, the ZCC is enabled on the input converter which allows the use of two‐step commutation. The two‐step commutation simplifies the implementation to a great extent. The presented scheme provides the required input/output performance similar to continuous PWM (CPWM) schemes. The proposed work is verified by the simulation and experimental results. The reduction in the switching losses of the IMC by the new scheme is verified based on the comparison with the CPWM scheme.
A Rare Tumor of the Nasal Cavity: Hemangiopericytoma
Authors: Kahane Kaustubh J. , Shrivastava Siddhartha , Jarandikar Apurva A. , Phatak Aishwarya S.
Published: June 2020

Hemangiopericytomas (HPCs) are soft tissue neoplasms that account for 3 to 5% of all soft tissue sarcomas and 1% of all vascular tumors. The vascular tumors originate from pericytes in the head and neck. The most common sites are the nasal cavity, paranasal sinuses, orbital region, parotid gland, and neck. HPC arising from the nose and paranasal sinuses is a rare entity. Till now, less than 200 cases have been reported in the literature. The treatment of choice is complete surgical resection, if possible, combined with preoperative embolization. We are presenting a rare case of HPC of the nasal cavity for its rarity and for concerns in management. This case was managed by endoscopic resection, which gave complete clearance of the disease and achieved better cosmesis.
Sorbents for water purification based on conjugated polymers
Authors: Sapurina Irina Yu. , Shishov Mikhail A. , Ivanova Valeria T.
Published: June 2020

The sorption properties of polymers with a polyconjugated chain structure (polyaniline and polypyrrole) are considered. The molecular mechanism of sorption by these polymers of various compounds such as heavy metal ions, toxic organic compounds and micropathogens, which are the most hazardous and stubborn contaminants in water, is discussed. The use of such sorbents to purify water from micropathogens, including bacteria and viruses, is addressed for the first time. The adsorption capacity of polyconjugated polymers for these types of contaminants, the efficiency of water treatment by these sorbents and characteristics of the currently used sorbents are analyzed. The applicability of polyaniline and polypyrrole and composites based on them as high-performance versatile sorbents for water treatment is discussed, taking into account the sorbent properties such as high stability, lack of solubility, lack of toxicity and ability to be regenerated and reused.

The bibliography includes 194 references.
Complexes of diamagnetic cations with radical anion ligands
Authors: Ershova Irina V. , Piskunov Alexandr V. , Cherkasov Vladimir K.
Published: June 2020

The review summarizes and analyzes the currently know data on the synthesis, molecular and electronic structures and magnetic properties of bi-, tri- and tetraradical complexes containing a diamagnetic metal ion and redox-active ligands in the paramagnetic form.

The bibliography includes 193 references.
Metadata mining
Authors: Hacke Melanie
Published: June 2020

Building on a quantitative survey that charts the presence of foreign cultures in the
Edinburgh Review and Quarterly Review, this essay pursues a closer understanding
of the ways in which British Romantic review periodicals engaged in intercultural mediation. After a brief
introduction of the project, the essay zooms in on some of the methodological issues related to the construction and
analysis of the database. As it is the first time that such quantitative research is being undertaken, particular
attention is given to the difficult balance between distant reading of metadata and close readings of specific review
articles, the selection of a representative corpus, and the position of the database within existing research.
The magazine as a medium of cultural translation
Authors: Ehrlicher Hanno
Published: June 2020

Our research project seeks to understand periodical publications as a medium of cultural
translation. This article explains some of the practical challenges which must be confronted when building a digital
corpus which transcends the logic of national archives. Focusing on a specific journal, La Gaceta
Literaria, the article then proceeds to explore data visualizations in a mixed-method approach which aims
at building a bridge between quantitative and qualitative analyses. The project also explores the periodical’s
ambition to construct a global community from an Ibero-American perspective, an aim not without (neo)imperialistic
implications. It does so with a particular focus on the role of translation, and the use of various languages used
within the journal in order to reach this goal.
Digital methods for revisiting twentieth-century magazines of ideas and culture
Authors: Malta Joana , Crespo de Andrade Luís , Lisboa Pedro
Published: June 2020

Considering magazines of ideas and culture are fundamental sources for the history of the first
half of the twentieth century, we propose a discussion of the use of digital and quantitative methods to broaden
knowledge on these historical objects, and bring to light new insights and understanding of the source material,
taking into account the aspects that make magazines a particularly complex object of study. After briefly examining
the advantages and feasibility of studying magazines using non-traditional historiographical methodologies, we explore
how the use of aggregated information can provide visual and comprehensive information not only on the history of
specific periodicals but also on their contents. Using various statistical procedures applied to data on the reception
of foreign authors and works we try to bring forward aspects of cultural transfer present in these magazines. For this
end, we use information gathered by the Semináro Livre de História das Ideias (History of Ideas Free Seminar) research
group for the Revistas de Ideias e Cultura (Magazines of Ideas and Culture) project, illustrating our argument with
data from A Águia, a republican magazine published in Portugal from 1910 to 1932.
The polyphony of periodicals
Authors: Brems Elke , McMartin Jack
Published: June 2020

This chapter introduces the concept of polyphonic voice to investigate the soundscape of a
translation-rich periodical. Using the anglophone Dutch periodical Delta and one of its principle
editors and translators, James S Holmes, as a case, it shows how the “silent voice” of a periodical’s patron can
create dissonance among the voices inscribed in its text; how a periodical’s collective voice can be gleaned through
paratext such as editors’ notes and manifestos; and how paratext can be analyzed to hearken an individual editorial
and translatorial voice within a translation-rich periodical’s collective soundscape.
Human African trypanosomiasis: current status and eradication efforts
Authors: Davis Christopher N. , Rock Kat S. , Keeling Matt J.
Published: June 2020

Epidemics of human African trypanosomiasis (HAT) in the twentieth century led to millions of deaths. However, since the start of the twenty-first century, there has been a continued decline in the number of reported cases, due to increased investment and prioritisation of control efforts. Systematic screening of at-risk areas and widespread access to increasingly advanced diagnostics and treatments, along with much improved vector control, has all helped to make disease elimination achievable in the near future. Despite the progress, the danger of disease resurgence is well known for HAT, and continued surveillance and treatment availability are essential. Additionally, many uncertainties regarding HAT transmission remain and combine to make potential disease eradication a complete unknown.
Evaluating Student’s Misconceptions and The Causes on Direct Current Concepts by Means of Four-Tier Multiple Choice Test
Authors: Aisahsari R , Ermawati F U
Published: June 2020

The main problem commonly faced in learning Physics is incompatibility between students’ pre knowledge in Physics concepts and the Physics concepts taught by teachers in schools. For example in Direct Current concepts, students have assumed that when there are two independent series and parallel current circuits, each composed of two identical electrical lamps as current loads, then the lamps on both circuits will light up at the same intensity. According to the Physics concept, however, the magnitude of current flows on a parallel circuit is greater than the magnitude of similar current flows on a series circuit, so that the intensity of the lamp light on the parallel circuit lights up brighter than that on the series circuit. This discrepancy may introduce a misconception to the students. This research aims to evaluate misconceptions profile of 30 numbers of 12th grade students in senior high school Ngimbang Lamongan East Java on Direct Current concepts and to identify the causes originating from themselves using four-tier multiple choice test developed by the author with ADDIE research design. The results show that all the students experienced misconceptions in throughout the sub concepts. The most frequent misconceptions was identified on the following sub concepts: Parallel Circuit, Series Circuit, Series-Parallel Circuit and Kirchoff’s 1 Law due to wrong intuition.
Identify 11th Grade of Senior High School Jogoroto students’ misconceptions on Dynamic Rotation and Rigid Body Equilibrium concepts using Four-Tier Diagnostic Test
Authors: Jannah E M , Ermawati F U
Published: June 2020

Understanding physics concepts is the main goal of learning process in school. However, it was frequently found that students faced difficulties to understand the concepts on physics taught in class. These difficulties mainly due to the difference between students ’ initial knowledge and the concepts taught by the teacher. For example, students assumed that a top can spin for a long time due to big speed of rotation, so it can maintain the spinning balance. However according to physics concept, the longer spinning balance is caused by the moment inertia is big. When the angular momentum of the top is conserved, the moment inertia can maintain the spinning of the top. This assumption frequently called as preconceptions. The incompatibility of preconceptions with the physics concepts above may lead misconceptions. This study aims to identify conception of students one science class in Senior High School of Jogoroto, Jombang on Dynamic Rotation and Rigid Body Equilibrium and their causes using four-tier diagnostic test. A total of 30 students participated in this study. The instrumen contains 16 numbers of physics-concepts questions. The highest conception is dominated by misconceptions that occur in rotational motion, equilibrium and center of gravity concepts was due to humanistic thinking and praconception.
Analysis Students’ Conception Using Four-Tier Diagnostic Test for Dynamic Fluid Concepts
Authors: Kurniawati D M , Ermawati F U
Published: June 2020

Based on the interview carried out by the authors to the students in Senior High School 1 Sidoarjo, East Java on Physics subject, it was obtained the fact that the Physics lesson was considered as a difficult subject. The most reason was that Physics contained many formulas and concepts which were not clearly taught by the teacher. Such situation has potentially caused misconceptions to the students. This paper reports the work to identify the conceptions of 11th grade Science class students of Senior High School 1 Sidoarjo, East Java on Dynamic Fluid concepts using a four-tier format of misconception diagnostic test. The causes of misconceptions were analyzed based on the internal aspects of students, namely preconception, associative thinking, humanistic thinking, incomplete or wrong reasoning and wrong intuition. The instrument consists of 15 numbers of multiple choice questions. The results showed that most students have scientific conception while the rest experienced misconception. The most misconception occured on the Bernoulli’s Law and its applications due to incomplete reason.