bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluations of the apparent soil resistivity and the reflection factor effects on the grounding grid performance in three‐layer soils
Authors: Gouda Osama E. , El‐Saied Tamer , Salem Waleed A.A. , Khater Asmaa M.A.
Published: January 2019

In this study, the apparent soil resistivity evaluation is estimated for three‐layer soils by four strategies and the obtained values are compared with experimental measurements done by using the four‐electrode method. Different methods are suggested with the aid of IEEE 80 to estimate the apparent soil resistivity of three‐layer soils, in which a grounding system consisting of a grid with rods is constructed. The effect of the reflection factor on the mesh and the step voltages, the grounding system resistance and the mesh voltage is investigated. It is concluded that the first three methods are close together, and also with the experimental findings done by the authors and others the fourth method gives some tolerance with the first three, but it is in agreement with the experimental measurements. It is concluded also that the reflection factors of non‐uniform soil have significant effects on the apparent soil resistivity, the step and the mesh voltages and the ground resistance. For the verification of the calculated results, experimental model is used. It is noted that the measured values are slightly high compared with the calculated values; the reason may be due to the boundary effects of the used model.
Particle swarm approach to the optimisation of trenched cantilever‐based MEMS piezoelectric energy harvesters
Authors: Kordrostami Zoheir , Roohizadegan Sajjad
Published: January 2019

A micro‐electro‐mechanical system (MEMS) trenched piezoelectric energy harvester based on a cantilever structure has been proposed. The trenched piezoelectric layer has increased the output voltage and the generated power. It also provides three additional design parameters such as the trench position, depth and length. A particle swarm approach has been used for optimisation of the piezoelectric energy harvester geometry with the aim of finding the optimum design which transfers the maximum harvested power to a definite load. The optimisations and comparisons have been made for unimorph, bimorph, trenched and non‐trenched cantilever beams. The results are quite revealing that the generated power for a trenched bimorph energy harvester is much larger than other structures. The optimum design found by particle swarm optimisation algorithm has asymmetric trenches in the top and bottom piezoelectric layers and can generate much more power than the unoptimised structure.
Application of MEMS‐based accelerometer wireless sensor systems for monitoring of blast‐induced ground vibration and structural health: a review
Authors: Ragam Prashanth , Devidas Sahebraoji Nimaje
Published: January 2019

Ubiquitous wireless sensor network (WSN) enables low‐cost monitoring applications such as blast‐induced ground vibration (BIGV) and structural health monitoring (SHM). In particular, monitoring and analysing the ambiguous BIGV waves are essential requisite to control and protect surrounding grievous damage structures. Similarly, improving health and longevity of structures using WSN is a new facet that owes to diminish the low‐cost installation. Recent advances in WSNs are forging new prospects for sensors. A variety of intelligent sensors are integrated into the wireless system to monitor environmental, and health of civil infrastructures. Considering the current trends in the area of development of wireless monitoring prototypes, Micro‐Electro‐Mechanical‐Systems (MEMS) accelerometer sensors are widely prevalent owing to the small size and inexpensive. In general, BIGV waves are less intensity and low‐frequency signals. Hence, it is essential to select an appropriate accelerometer to detect micro‐vibration waves. The study exemplifies a summarised review of recently made MEMS‐based accelerometer wireless systems for intelligent and reliable monitoring of BIGV and SHM since the last decade. This research effort focuses on the numerous adopted accelerometers and their characteristics such as sensitivity, noise density, measurement range, bandwidth, resolution, network topologies, and performance of designed systems to analyse the micro‐vibration levels comprehensively.
Study on surface electric field and ground nominal electric field of HVDC transimission line on slope terrain
Authors: Gao Chenguang , Liu Yuanqing , Zhao Jiangtao , Zhang Xirun , Li Wenyu , Han Hui , Zhang Jingchen
Published: January 2019

In order to study the fast calculation method of a surface electric field of the arbitrary‐quantity bundled conductor and a ground nominal electric field of the HVDC transmission line on slope terrain. Based on the basic principles of the image method, this paper deduces the calculation formula of the surface maximum electric field of the arbitrary‐quantity bundled conductor and the ground nominal electric field of the HVDC transmission line with single bipolar horizontal arrangement over the slope terrain by making the reasonable approximation and equivalence to the actual situation. Compared with the finite element method, the results got from the formula proposed in this paper verify that these formulas are accurate and valid. The effects of slope inclination, pole–pole spacing of the conductor on the electric field of the conductor surface and the ground nominal electric field of the HVDC transmission line are analyzed and obtained. The results of research indicate that the inclination of the slope and the pole–pole spacing of the conductor have a great influence on the conductor surface electric field and the ground nominal electric field. When the HVDC transmission line is erected on the slope terrain, the formula proposed in this paper can provide references for circuit design and electromagnetic environment analysis.
Hybrid‐wave modulation for modular multilevel high‐frequency DC converter in DC distribution application
Authors: Wang Yu , Wang Yuewu , Zhang Guidong , Chen Si‐Zhe , Zhang Yun
Published: January 2019

Compared with AC distribution networks, DC distribution networks reduce the utilisation of power converters, power loss, and construction cost. In DC distribution network, the high‐frequency modular multilevel DC converter (MDCC), which connects the low‐voltage DC link with medium‐ or high‐voltage DC links, becomes a practical equipment to realise the bus connection, voltage conversion, and electrical isolation. Especially, high‐frequency link (HFL) modulation plays an important role in converter performance. The square‐wave (SW) modulation obtains better power transfer capability and higher DC voltage utilisation. However, the SW modulation leads to a large dv /dt stress upon HFL transformer. The sinusoidal, triangle and quasi‐square‐wave (QSW) modulations reduce dv /dt and harmonics significantly. However, the power transfer capability and DC voltage utilisation are also reduced. To address dv /dt stress problem, ensure high DC‐voltage utilisation and maintain a strong power transfer capability simultaneously, a hybrid‐wave modulation strategy, which composed of QSW and SW modulation, is proposed for MDCC. The experimental results verify the analysis and proposed scheme.
Influence of the structure of transmission line on harmonics distribution in DC system
Authors: Yiming Ji , Fangjie Wu , Yanbin Zhang
Published: January 2019

The transmission distance of DC project is always long, and along the transmission distance, the structure of lines and towers varies according to local environment. It is hard to build a precise harmonic model composed of different sections of line with exact line parameters, so it is important to research the influence of line structure on the harmonic distribution in system and find the key parameters, in order to simplify the model. By building models of different line parameters in harmonic analysis program and calculating, it is found that the line spacing has a strong influence, the influence of height weakens when higher, the earth resistivity, ground wires and conductor type affect little, but the bundle number and spacing affect a lot, especially at low frequency. The influence rules on filter equipment are the same. The EMTPC simulation verified these conclusions. Combined with the practical project design convention, the height is the most important subsection basis. It is verified that a simplified model of a few line sections of different parameters can simulate the harmonics in project exactly.
Study on pre‐charging process and pre‐insertion resistors selection of VSC‐HVDC system with different MMC topologies
Authors: Lu Yuxin , Huang Ying , Zhao Xiaobin , Xu Dizhen , Guo Long , Qin Kang
Published: January 2019

Here, the uncontrolled rectification pre‐charging characteristics of the VSC‐HVDC system with different modular multilevel converter (MMC) topologies such as full‐bridge, half‐bridge, and hybrid topologies are proposed based on theoretical analysis and PSCAD/EMTDC simulations. Different MMC topologies have a great impact on the selection of pre‐insertion resistors. The surge energy of pre‐insertion resistors is the lowest with the full‐bridge sub‐module (FBSM) MMC, while much higher with the half‐bridge sub‐module (HBSM) MMC. In order to prevent start‐up failure caused by extremely non‐uniform voltage between FBSM and HBSM of hybrid MMC, the FBSM should be turned to half‐bridge state by valve control system as soon as possible so as to carry out the second charge, and then balance the sub‐modules voltage by bypass certain high‐voltage sub‐modules. The half‐controlled charging process has a great influence on the absorbed energy of the pre‐insertion resistors of hybrid MMC. The research results can be used to guide the selection of VSC‐HVDC pre‐insertion resistors and start‐up strategy making.
Improved control strategy of TFAPF in active distribution networks
Authors: Yizhao Liu , Huanming Liu , Guangwei Zhang , Da Lei , Jinhao Wang , Xiao Chang
Published: January 2019

In order to solve the deterioration of power quality caused by power electronic devices in active distribution networks, it is necessary to improve the three‐phase four‐wire active power filters (TFAPF) control strategy. This study adopts the non‐harmonic detection and proposes an improved control strategy of TFAPF based on the multi‐model principle. Firstly, the mathematical model of TFAPF in the stationary coordinate system is established by replacing the network side current and the DC bus voltage directly as the state variables. Secondly, TFAPF in active distribution networks requires the power fluctuation and fast dynamic response, the proposed control strategy of TFAPF in the stationary coordinate system is applied, namely proportional integral, vector resonant and repetitive control composite controller as the current loop controller of TFAPF with a fast dynamic response, high accuracy and small amount of calculation, provide guarantee for the power quality in active distribution networks. Finally, the feasibility of the proposed control strategy is verified by simulation.
Fractal algorithm for 3D‐printed continuous porous scaffold design
Authors: Zhao Zongyue , Chen Xiaojun
Published: January 2019

In practice, 3D modelling software, such as UG and Pro/E, are commonly adopted to design porous scaffolds within given contours. However, this manual method is quite time‐consuming and complicated with poor adaptability. In this study, a novel facial algorithm is proposed for smart scaffold design. By forming a dendritic fractal network, the second‐order uniformity and complete connectivity of pores are guaranteed while considering the axial symmetry of certain orthopaedic implants, and the algorithm is adapted for concave and hollow contour shapes. Through experiments, the stability of the algorithm and the characteristics of the two vital performance indicators, i.e. porosity and surface area ratio R, are studied. The results show that P and of the generated model are insensitive to the shape of the input model, which proves the stability of authors’ method, and the maximum available porosity reaches 78%, higher than the maximum effective porosity found in the literature.
Development of compact portable ultrasound robot for home healthcare
Authors: Sasaki Yudai , Eura Fumio , Kobayashi Kento , Kondo Ryosuke , Tomita Kyohei , Nishiyama Yu , Tsukihara Hiroyuki , Matumoto Naoki , Koizumi Norihiro
Published: January 2019

Robotic medical ultrasound can support diagnostics and alleviate fatigues. However, state‐of‐the‐art ultrasound devices are too large and complex for home healthcare. Moreover, organs move in accordance with respiration. This movement changes the ultrasound image pattern and it is difficult for the operator to diagnose easily and accurately. To cope with these problems, the authors newly developed a compact portable ultrasound diagnostic robot for home healthcare, which compensate the organ motion. It can support those who find it difficult to visit a hospital for temporal, spatial, or physical reasons. A robust template matching method to servo the target was applied. Specifically, this robot moves to the target, whose position is detected by finding and identifying the image position of the target in the real‐time input images. The authors also applied a multi‐threading algorithm with two threads to enhance the real‐time performance. One is for image processing with template matching. Another is for robot control to servo the target. Experimental results show that their proposed robot and algorithms can be suppressed to 25.2% motion in pk‐to‐pk for the periodic phantom organ motion (period of 3 s and of pk‐to‐pk 40 mm).
High‐modulation depth modulator based on double‐layer graphene with a low bias voltage
Authors: Dapeng Zhou , Binggang Xiao , Lihua Xiao , Fenglei Guo , Xiumin Wang
Published: January 2019

An efficient modulation can be obtained by graphene due to its outstanding light‐matter interaction, and many kinds of modulators based on graphene have been studied during the last couple of years. However, there still exist unsolved issues in graphene‐based modulators, such as how to make a balance between modulation depth and modulation bandwidth. This work proposes a reflective modulator with relatively high‐modulation depth and wide working bandwidth. The proposed modulator has a simple five‐layered structure of graphene–silica–graphene–silicon‐metal. They use an effective method of finite element method to simulate the performance of this modulator, and obtain a modulation depth of 96% with a low bias voltage of ∼4 V. Furthermore, they calculate the modulation speed by the equivalent circuit method, and obtain the maximum modulation speed of about 25 kHz and a wide broadband of 72 kHz from theoretical analysis. Therefore, this high‐performance modulator provides an effective method for terahertz communication devices.
Photospheric plasma and magnetic field dynamics during the formation of solar AR 11190
Authors: Campos Rozo J. I. , Utz D. , Vargas Domínguez S. , Veronig A. , Van Doorsselaere T.
Published: January 2019

Context.The Sun features on its surface typical flow patterns called the granulation, mesogranulation, and supergranulation. These patterns arise due to convective flows transporting energy from the interior of the Sun to its surface. The other well known elements structuring the solar photosphere are magnetic fields arranged from single, isolated, small-scale flux tubes to large and extended regions visible as sunspots and active regions.

Aims.In this paper we will shed light on the interaction between the convective flows in large-scale cells as well as the large-scale magnetic fields in active regions, and investigate in detail the statistical distribution of flow velocities during the evolution and formation of National Oceanic and Atmospheric Administration active region 11190.

Methods.To do so, we employed local correlation tracking methods on data obtained by the Solar Dynamics Observatory in the continuum as well as on processed line-of-sight magnetograms.

Results.We find that the flow fields in an active region can be modelled by a two-component distribution. One component is very stable, follows a Rayleigh distribution, and can be assigned to the background flows, whilst the other component is variable in strength and velocity range and can be attributed to the flux emergence visible both in the continuum maps as well as magnetograms. Generally, the plasma flows, as seen by the distribution of the magnitude of the velocity, follow a Rayleigh distribution even through the time of formation of active regions. However, at certain moments of large-scale fast flux emergence, a second component featuring higher velocities is formed in the velocity magnitudes distribution.

Conclusions.The plasma flows are generally highly correlated to the motion of magnetic elements and vice versa except during the times of fast magnetic flux emergence as observed by rising magnetic elements. At these times, the magnetic fields are found to move faster than the corresponding plasma.
Asteroseismology of the Hyades red giant and planet host ϵ Tauri
Authors: Arentoft T. , Grundahl F. , White T. R. , Slumstrup D. , Handberg R. , Lund M. N. , Brogaard K. , Andersen M. F. , Silva Aguirre V. , Zhang C. , Chen X. , Yan Z. , Pope B. J. S. , Huber D. , Kjeldsen H. , Christensen-Dalsgaard J. , Jessen-Hansen J. , Antoci V. , Frandsen S. , Bedding T. R. , Pallé P. L. , Garcia R. A. , Deng L. , Hon M. , Stello D. , Jørgensen U. G.
Published: January 2019

Context. Asteroseismic analysis of solar-like stars allows us to determine physical parameters such as stellar mass, with a higher precision compared to most other methods. Even in a well-studied cluster such as the Hyades, the masses of the red giant stars are not well known, and previous mass estimates are based on model calculations (isochrones). The four known red giants in the Hyades are assumed to be clump (core-helium-burning) stars based on their positions in colour-magnitude diagrams, however asteroseismology offers an opportunity to test this assumption.

Aims. Using asteroseismic techniques combined with other methods, we aim to derive physical parameters and the evolutionary stage for the planet hosting star ϵ Tau, which is one of the four red giants located in the Hyades.

Methods. We analysed time-series data from both ground and space to perform the asteroseismic analysis. By combining high signal-to-noise radial-velocity data from the ground-based SONG network with continuous space-based data from the revised Kepler mission K2, we derive and characterize 27 individual oscillation modes for ϵ Tau, along with global oscillation parameters such as the large frequency separation Δν and the ratio between the amplitude of the oscillations measured in radial velocity and intensity as a function of frequency. The latter has been measured previously for only two stars, the Sun and Procyon. Combining the seismic analysis with interferometric and spectroscopic measurements, we derive physical parameters for ϵ Tau, and discuss its evolutionary status.

Results. Along with other physical parameters, we derive an asteroseismic mass for ϵ Tau of M = 2.458 ± 0.073 M⊙, which is slightly lower than previous estimates, and which leads to a revised minimum mass of the planetary companion. Noting that the SONG and K2 data are non-simultaneous, we estimate the amplitude ratio between intensity and radial velocity to be 42.2 ± 2.3 ppm m−1 s, which is higher than expected from scaling relations.
Spectral observations of X Persei: Connection between Hα and X-ray emission
Authors: Zamanov R. , Stoyanov K. A. , Wolter U. , Marchev D. , Petrov N. I.
Published: January 2019

We present spectroscopic observations of the Be/X-ray binary X Per obtained during the period 1999–2018. Using new and published data, we found that during “disc-rise” the expansion velocity of the circumstellar disc is 0.4–0.7 km s−1. Our results suggest that the disc radius in recent decades show evidence of resonant truncation of the disc by resonances 10:1, 3:1, and 2:1, while the maximum disc size is larger than the Roche lobe of the primary and smaller than the closest approach of the neutron star. We find correlation between equivalent width of Hα emission line (Wα) and the X-ray flux, which is visible when 15 Å < Wα ≤ 40 Å. The correlation is probably due to wind Roche lobe overflow.
Lower bound for the perimeter density at singular points of a minimizing cluster in ℝN
Authors: Hirsch Jonas , Marini Michele
Published: January 2019

In this paper, we study the blow-ups of the singular points in the boundary of a minimizing cluster lying in the interface of more than two chambers. We establish a sharp lower bound for the perimeter density at those points and we prove that this bound is rigid, namely having the lowest possible density completely characterizes the blow-up.
Un critique andalou d’al-Fārisī : la Risālat al-ʾIfṣāḥ d’Ibn al-Ṭarāwa
Authors: Guillaume Jean-Patrick
Published: January 2019

La Risālat al-ʾIfṣāḥ du grammairien andalou Ibn al-Ṭarāwa (m. 526/1132 ou 528/1134) est une critique d’un abrégé de grammaire alors très répandu au Proche-Orient, le Kitāb al-ʾĪḍāḥ d’al-Fārisī (m. 377/987). D’un ton violemment polémique, elle se caractérise principalement par une fidélité hautement affichée à la lettre du Kitāb de Sībawayhi (m. 180/796 ?), le texte fondateur de la discipline, mais aussi par des opinions souvent originales, en rupture avec la doctrine canonique telle qu’elle est conçue à l’époque.
Un grammairien “oublié” : Ibn Muʿṭī
Authors: Larcher Pierre
Published: January 2019

Ibn Muʿṭī est un grammairien originaire du Maghreb, mais qui a émigré au Machrek, où il est mort en 628/1231. Auteur de la premièreʾAlfiyya, il est aussi l’auteur d’un ouvrage en prose intituléal-Fuṣūl al-ḫamsūn. Celui-ci tire son nom de ce qu’il est divisé en « cinquante sections », mais rassemblées en cinq chapitres. Il est donc comparable auMufaṣṣaldu Persan al-Zamaḫšarī (m. 538/1144), divisé en sections, rassemblées en quatre parties. Chez al-Zamaḫšarī l’exposé grammatical se fait selon les parties du discours d’une part, la flexibilité/inflexibilité désinentielles (ʾiʿrāb/bināʾ) de ces parties d’autre part. Chez Ibn Muʿṭī, il se fait selon leʿamal(litt. « action »), qui est avec leʾiʿrābdans la relation de cause à effet. C’est ce qui explique la priorité donnée au verbe (ch. 2), considéré comme le régissant principal, les autres régissants étant regroupés dans le chapitre 3. C’est là l’influence duǦumald’al-Zaǧǧāǧī (m. 337/949 ou 339-340/950-952), une des références majeures de la grammaire arabe dans l’Occident musulman. Elle est particulièrement sensible dans la double extension dutaʿaddīet la classification des compléments du verbe.
An Andalusian lexicographer reading an Oriental grammarian
Authors: Ayoub Georgine
Published: January 2019

In his important dictionary, al-Muḫaṣṣaṣ, Ibn Sīda, the most distinguished Andalusian lexicographer, born in Murcia and died in Denia in 458/1066, presents, as the foundations of his work, a conception of the nature of language and the origin of speech. The latter theory is borrowed, almost literally, from al-Ḫaṣāʾiṣ, without this being stated explicitly. Al-Ḫaṣāʾiṣ, as we know, is the epistemological work of Ibn Ǧinnī, a great Baġdādi grammarian of Greek origin of the 4th/10th century. As Ibn Ǧinnī’s extract seems to be taken literally, Ibn Sīda’s passage has been described as a servile borrowing and has not, to our knowledge, been more extensively studied. I will try in this paper to show that this is, in fact, a reading with significant differences about some important points, leading to a somewhat different conception of language. Some aspects of Ibn Sīda’s relation to Ibn Ǧinnī’s work will be examined in this regard.
La fusion nucléaire, le troisième pilier structurant du nucléaire chinois
Authors: Allard Léonie , Poinssot Christophe
Published: January 2019

En matière d’énergie nucléaire, la Chine se projette d’ores et deja dans l’avenir et reflechit aux etapes futures de deploiement de l’energie de la fusion en reflechissant a l’opportunite de developper ses propres demonstrateurs industriels post-ITER, tout en continuant de participer aux projets multilateraux.
Splenic Artery Embolization: Endovascular and Percutaneous Trans-splenic Approach
Authors: Banode Pankaj , Sharma Gaurav
Published: January 2019

Background Splenic artery embolization is becoming a widely acceptable procedure for nonsurgical management in many clinical settings such as pseudoaneurysms or to salvage splenic functions in portal hypertension, hypersplenism, and secondary prophylaxis in variceal hemorrhage. Various published meta-analyses of splenic artery embolization found an overall success rate of 90% in vascular abnormality.

Methods Retrospective study of all splenic artery embolization procedures in 1 year (January 2017–2018) to analyze various indications, procedure technique, and its modification as well as outcome measurement and complications.

Results Total 16 splenic artery embolization procedures were performed including one case of percutaneous trans-splenic glue embolization in 1-year duration.

Procedure Indication It included pseudoaneurysm (n = 7, 44%); trauma (n = 1, 6%); adjuvant to surgical splenectomy in hypersplenism (n = 3, 18%); secondary prophylaxis in portal hypertension, portosystemic varices with/without reduced platelet counts, or ascites (n = 4, 25%); and Budd-Chiari syndrome (n = 1, 6%). Total 13 (81%) procedures were elective, whereas emergency embolization was performed in 3 (18.7%). Endovascular technical success was 93.7% (n = 15) cases. Percutaneous trans-splenic embolization was performed in one (6%) case in which access to bleeding point was not possible. The embolic agents included combination of metallic coils (n = 14, 87.5%), Gelfoam (n = 6, 37.5%), polyvinyl alcohol (PVA) particles (n = 5, 31%), and cyanoacrylate glue (n = 3, 18.7%). Complication rate was low with development of splenic abscess with infected pyothorax in one (6%) case of hypersplenism requiring pigtail drainage with uneventful full recovery.

Conclusion Splenic artery embolization provides safer nonsurgical options in management of cases such as trauma, hypersplenism, portal hypertension for control of hemorrhage and preservation of splenic function. Endovascular embolization facilitates complete exclusion of pseudoaneurysms in majority with percutaneous splenic embolization using glue or coils as a safer alternative where endovascular access to bleeding vessels is difficult.
Exploring the Diagnostic Efficacy of Fine-Needle Aspiration Cytology in Thyroid Nodules ≥ 4 cm: Results from a Tertiary Health Care Center in Jharkhand
Authors: Bhardwaj Rajeev , Rana Rishabh Kumar
Published: January 2019

Background Any nodules of the thyroid, ≥ 4 cm, are generally associated with false-negative results for malignancy on fine-needle aspiration cytology (FNAC), which generally are confirmed cases of malignancy after histopathologic examinations.

Methods A retrospective hospital-based study was done in which data of patients having thyroid lesions ≥ 4 cm were reviewed. We checked the FNAC and histopathologic examination done on these lesions. Ultrasonography (USG)–guided aspiration records were also assessed. Sensitivity and specificity of FNAC for the detection of neoplastic or malignant lesions was determined.

Results A total of 192 patients (57 female) were included in study. Preoperative fine-needle aspiration (FNA) biopsies were categorized as negative for malignancy (n = 183, 63%), suspicious (n = 6, 4%), and malignant (n = 4, 2%). Final pathology of nodule was found to be benign in 157 (81.35%) patients, whereas in 36 (18.65%) patients, nodules were found to be malignant.

Conclusion In this study, we found the malignancy rate of thyroid nodules ≥ 4 cm to be similar to the accepted malignancy rate of smaller thyroid nodules. We missed 32 cases of malignancy on FNAC. Because of high incidence of thyroid malignancy, all nodules ≥ 4 cm must undergo histopathologic examination.
Hydroxyapatite Crystal Deposition Disease of the Shoulder: A Review of Cases and Literature
Authors: Ravikanth Reddy , Kamalasekar Kanagasabai , Abraham Manu Jacob , Alapati Ashok
Published: January 2019

Hydroxyapatite crystal deposition diseases (HADDs) are characterized by deposition of insoluble crystals within the joints and periarticular soft tissues, initiating inflammatory destructive reaction. Calcium hydroxyapatite (CHA) is the most common type of calcium in human bone and is also the most common pathologic calcification found in the body. There are three phases of the disease: silent, mechanical, and adhesive phases. The shoulder is the most common site of HADD. CHA crystals are non-birefringent in polarized light. Radiographic characteristics include homogenous, amorphous densities without trabeculations that are variable in size, ovoid, triangular, or linear. The first imaging modalities to identify calcific tendinitis (CT) were X-ray and ultrasound, as calcium deposits are readily identifiable on both. Treatment is chiefly conservative, including nonsteroidal anti-inflammatory drugs (NSAIDs), local heat application, and physiotherapy. Local corticosteroid injections may also be of benefit. When intra-articular, CHA crystals can cause joint destruction such as “ Milwaukee shoulder.” In the acute symptomatic phase of HADD, called acute calcific periarthritis, soft tissue and osseous edema can be present and needs to be differentiated from infection, tumor, and trauma.
Neuromorphic thermal-electric circuits based on phase-change VO2 thin-film memristor elements
Authors: Lappalainen J. , Mizsei J. , Huotari M.
Published: January 2019

The basis of the powerful operation of the brain is the variability of neuron operation, i.e., it can be digital or analog, and the logic operation of a neuron-based system can be parallel and series. The challenge is to set up an artificial intelligent architecture that mimics neuro-biological architectures present in the nervous system. Our proposed new active device (phonon transistor = phonsistor) and thermal electric logic circuit (TELC) seem to be appropriate devices for neuron modeling. Key elements of the phonsistor and TELC are memristors realized by VO2 phase change output resistors integrated with dissipating elements as inputs. These components are coupled to each other by thermal and/or electrical effects. On short distances, the information can be carried by heat diffusion and on longer distances by electrical signals. This is a similarity with human neurons where the information is carried by diffusing neurotransmitter molecules on short distances and electrically by the axons on longer distances. For example, very new ideas are presented of neuromorphic circuits for mimicking the biological neuron synapse operation and the action potential generation. Further similarities with biological neural systems are the auto-oscillation phenomenon with chaotic properties, the ability of integrating subthreshold excitations within the thermal time constant, and the memory effect of the memristive components. The TELC should be compatible with CMOS technology, as the realization of both systems utilizes conventional thin-film technology steps at similar temperature ranges. The physical appearance and construction of the TELC gate are also similar to the neuron.
Epitaxial integration of high-mobility La-doped BaSnO3 thin films with silicon
Authors: Wang Zhe , Paik Hanjong , Chen Zhen , Muller David A. , Schlom Darrell G.
Published: January 2019

La-doped BaSnO3 has been epitaxially integrated with (001) Si using an SrTiO3 buffer layer via molecular-beam epitaxy (MBE). A 254 nm thick undoped BaSnO3 buffer layer was grown to enhance the mobility of the overlying La-doped BaSnO3 layer. The x-ray diffraction rocking curve of the BaSnO3 002 peak has a full width at half maximum of 0.02°. At room temperature, the resistivity of the La-doped BaSnO3 film is 3.6 × 10−4 Ω cm and the mobility is 128 cm2 V−1 s−1 at a carrier concentration of 1.4 × 1020 cm−3. These values compare favorably to those of La-doped BaSnO3 films grown by all techniques other than MBE on single-crystal oxide substrates. Our work opens an exciting arena for integrating hyper-functional oxide electronics that make use of high-mobility oxide films with the workhorse of the semiconductor industry, silicon.
State space geometry of the chaotic pilot-wave hydrodynamics
Authors: Budanur Nazmi Burak , Fleury Marc
Published: January 2019

We consider the motion of a droplet bouncing on a vibrating bath of the same fluid in the presence of a central potential. We formulate a rotation symmetry-reduced description of this system, which allows for the straightforward application of dynamical systems theory tools. As an illustration of the utility of the symmetry reduction, we apply it to a model of the pilot-wave system with a central harmonic force. We begin our analysis by identifying local bifurcations and the onset of chaos. We then describe the emergence of chaotic regions and their merging bifurcations, which lead to the formation of a global attractor. In this final regime, the droplet’s angular momentum spontaneously changes its sign as observed in the experiments of Perrard et al. [Phys. Rev. Lett. 113(10), 104101 (2014)].
Ecological optimization for a combined diesel-organic Rankine cycle
Authors: Ma Zheshu , Chen Yan , Wu Junhua
Published: January 2019

A mathematical model of a steady combined diesel-organic Rankine cycle with finite heat resistance and heat leakage is proposed. Performance of the studied combined cycle has been numerically analyzed based on the ecological criterion and endothermic rate optimization method. The variations of optimal power, optimal efficiency and optimal ecological criterion with the endothermic rate, and the relations between optimal ecological criterion, optimal efficiency and optimal power are studied by numerical calculation. Results show that the optimal power does not vary with the endothermic rate; optimal ecological criterion and optimal efficiency decrease with the increase of heat leakage. The efficiency under the optimal ecological criterion is larger than that under the optimal power while both of them are less than the optimal efficiency. The heat leakage brings the quantitative and qualitative impact on the power output and efficiency of the combined cycle. The power output, ecological criterion and efficiency of ORC increase with the increasing evaporation temperature and superheated temperature.
Strategies for p-type doping of ZnGeN2
Authors: Adamski Nicholas L. , Zhu Zhen , Wickramaratne Darshana , Van de Walle Chris G.
Published: January 2019

ZnGeN2 has been proposed as an attractive semiconductor for a number of applications, but doping is largely unexplored. We examine the behavior of Li, Cu, Al, Ga, In, and C as candidate acceptors using hybrid density functional theory. Cu, In, and C give rise to deep acceptor levels, but Li, Al, or Ga could potentially lead to p-type conductivity. Al is particularly attractive since it has an ionization energy of 0.24 eV, comparable to Mg in GaN. However, self-compensation due to wrong-site incorporation is a serious issue. We demonstrate that co-doping with hydrogen can be used to overcome this problem.
Quantum dynamical investigation of product state distributions of the F + CH3OH → HF + CH3O reaction via photodetachment of the F−(HOCH3) anion
Authors: Guo Lifen , Li Jun , Ma Jianyi , Guo Hua
Published: January 2019

The photodetachment of the F−(HOCH3) anion, which sheds light on the post-transition-state dynamics of the F + CH3OH → HF + CH3O reaction, is investigated using a reduced-dimensional quantum wave packet method on ab initio based potential energy surfaces for both the neutral and anionic species. The detachment of an electron in the anion precursor produces both bound and resonance species in a hydrogen-bonded potential well in the product channel, in qualitative agreement with the photoelectron-photofragment coincidence (PPC) spectrum. The measured photoelectron-photofragment coincidence spectroscopy is reproduced by the quantum calculations. Our results indicated that the HF product is vibrationally excited, while the OCH3 product is internally cold, thus providing unambiguous assignments of the experimental spectrum.
Energy spectrum of surface electrons over the 3He–4He solution film with inhomogeneous isotope distribution
Authors: Sokolova E. S. , Sokolov S. S.
Published: January 2019

The energy spectrum of surface electrons localized over a 3He–4He liquid solution film covering a solid substrate is theoretically determined using the variational method. Two models of the spatial distribution of helium isotopes over the film height are considered. In one of them, it is believed that the film is stratified, and a continuous linear change in concentration is assumed in the second one. The potential energy of an electron is determined by the method of solving the Poisson equation for the electrostatic potential and in the gas approximation. Furthermore, it is established that the results of both methods practically coincide for a stratified film. The dependence of the energy gap between the ground and first excited states of surface electrons as a function of the film thickness is determined. Comparison of the results for the considered models of the film structure is carried out. The possibility of using the results obtained in an experimental study of the spatial isotopic distribution in a helium solution by the neutron scattering method is discussed.
Electronic properties of gold nanotubes (5, 3) and (5, 0) in the Hubbard model in the static fluctuation approximation
Authors: Mironov G. I. , Sozykina E. R.
Published: January 2019

A theoretical analysis of the electronic properties of single-walled gold nanotubes with chiralities (5, 3) and (5, 0) with the growth of nanotubes is presented. The results of the study of single-walled gold nanotubes with chiralities (5, 3) and (5, 0) were compared with the results obtained by X.P. Yang and J.M. Dong. The Hubbard model with a certain selection of model parameters allows us to explain the data obtained using the electron density functional theory. According to our results, only the semiconductor–metal transition occurs with the growth of gold nanotubes, and there are no semiconductor–metal–semiconductor–metal “oscillations”, which were indicated in the following work: X.P. Yang and J.M. Dong, Phys. Rev. B 71, 233403 (2005).
On the statistical thermodynamics of quantum gases
Authors: Bobrov V. B.
Published: January 2019

On the basis of the grand canonical Gibbs ensemble, using the virial theorem and the equations of motion for Green’s functions, it was shown that the thermodynamic functions of a one-component quantum gas are uniquely determined by the two-particle Green’s function outside the framework of perturbation theory. A thermodynamic self-consistency condition is formulated, which makes it possible to select approximate expressions for the two-particle Green’s function.
On the Theory of the Magnetic Quantum Phase Transitions of the First Kind in Van Vleck Ising Antiferromagnet
Authors: Lyashenko T. I. , Kalita V. M. , Loktev V. M.
Published: January 2019

Quantum phase transitions induced by an external magnetic field in a Van Vleck paramagnet with ion spin S = 1, competition of an easy-plane single-particle anisotropy and Ising spin-spin interactions have been investigated. Phase transformations have been described using the Lagrange function, minimization of which is performed by the coefficients of linear combination of the spin wave functions that determine the magnet ground state. It was shown that such an approach is consistent with the Landau theory of phase transitions of the 1st kind. The result obtained showed that the transition from the Van Vleck paramagnetic (singlet) phase to the ferromagnetic phase occurs by forming an intermediate state with only one magnetized spin sublattice.
Friedel–Crafts Chemistry. Part 53. Divergent and Diversity-Oriented Synthesis of Condensed Indole Scaffolds via Friedel–Crafts Ring Closure Approach
Authors: Abd El-Aal Hassan A. K. , Khalaf Ali A.
Published: January 2019

A series of indole-fused medium-sized N-heterocyclic systems 10a–h were prepared from laboratory-synthesized indole-based esters 9a–h via intramolecular Friedel–Crafts cyclizations induced by both trifluoromethanesulfonic acid and AlCl3/CH3NO2 catalysts under suitable conditions. The synthetic sequence to precursors 9a–h that started from simple N-methylindole-2-carboxylic acid involved conversion to aminoindoles 2a, b, reaction with α,β-unsaturated acid chlorides to yield acyclic amides 5a–d, ring closure to tricyclic lactams 6a–d, and carbonyl reduction to respective pyrido and azepino tricyclic amines 7a–d, which finally underwent N-alkylations with α- or β-haloesters to produce the required ester precursors. The structures of synthesized compounds without stereochemical implications are established using both spectral and analytical data.
Voluntary sustainability standards could significantly reduce detrimental impacts of global agriculture
Authors: Smith W. K. , Nelson E. , Johnson J. A. , Polasky S. , Milder J. C. , Gerber J. S. , West P. C. , Siebert S. , Brauman K. A. , Carlson K. M. , Arbuthnot M. , Rozza J. P. , Pennington D. N.
Published: January 2019

Significance

Voluntary sustainability standards (VSS) may be an effective way to reduce the negative impacts of agriculture at regional to global scales. Here, we present an approach that highlights the potential of VSS to reduce some of the negative externalities associated with agriculture production. To illustrate this potential, we show that VSS could reduce the global environmental impacts from growing sugarcane. Further, most of this environmental benefit comes from targeting just 10% of production area. To realize these environmental gains, incentives for VSS adoption need to be sufficient to cover the costs of criteria compliance. Determining these costs and public and private-sector mechanisms for efficiently transferring VSS-adoption subsidies to farmers and millers are key future research needs.
Involutions on pro-𝑝-Iwahori Hecke algebras
Authors: Abe Noriyuki
Published: January 2019

The pro-

p
p

-Iwahori Hecke algebra has an involution

ι
\iota

defined in terms of the Iwahori-Matsumoto basis. Then for a module

π
\pi

of pro-

p
p

-Iwahori Hecke,

π
ι

=
π
∘
ι

\pi ^\iota = \pi \circ \iota

is also a module. We calculate

π
ι

\pi ^\iota

for simple modules

π
\pi

. We also calculate the dual of

π
\pi

. These calculations will be used for calculating the extensions between simple modules.
Before and After the Weser Case: Legal Application of the Water Framework Directive Environmental Objectives in Sweden
Authors: Söderasp Johanna , Pettersson Maria
Published: January 2019

The EU Water Framework Directive (WFD) prescribes environmental objectives and an adaptive water governance system. This article analyses the Swedish implementation of the WFD through a review of high-profile Swedish court cases regarding the application of the WFD environmental objectives in individual authorisation processes for water operations. The selection of court cases represents both the time before and after the Court of Justice of the European Union’s Weser case in 2015. The results indicate an inertial tendency in the legal application of the WFD environmental objectives in Swedish courts, including a reluctance to fully apply EU law as interpreted by the CJEU. The overall conclusion is that traditional legal certainty aspects often trump flexibility and a high level of environmental protection as desired in the adaptive water governance system of the WFD. This raises questions about judicial preconceptions and the procedural autonomy of the Member States vis-à-vis the ‘effet utile’ of EU law through judicial implementation.
Wireless High-Frequency Spinal Cord Stimulation (10 kHz) Compared with Multiwaveform Low-Frequency Spinal Cord Stimulation in the Management of Chronic Pain in Failed Back Surgery Syndrome Subjects: Preliminary Results of a Multicenter, Prospective Randomized Controlled Study
Authors: Bolash Robert , Creamer Michael , Rauck Richard , Vahedifar Payam , Calodney Aaron , Fox Ira , Özaktay Cuneyt , Panchal Sunil , Vanquathem Niek , Yasin Mezaun
Published: January 2019

Background

This study aimed to evaluate the wireless Freedom Spinal Cord Stimulator (WSCS) System for the treatment of chronic back and/or leg pain associated with failed back surgery syndrome (FBSS) refractory to standard medical treatment utilizing 10-kHz stimulation (high-frequency [HF]) in comparison with 10–1,500-Hz stimulation (low-frequency [LF]) waveforms.

Methods

Ninety-nine subjects were randomized in a 1:1 ratio to receive either HF or LF stimulation waveforms utilizing the same Freedom WSCS System. All subjects were implanted with two 8-electrode arrays in the exact same anatomical positions within the dorsal epidural spinal column, with the top electrode positioned at the T8 and T9 vertebrae levels, respectively, and the wireless receiver placed under the skin in a subcutaneous pocket.

Results

Seventy-two (HF: N = 38; LF: N = 34) subjects had completed the six-month follow-up after an initial 30-day trial period at the time of this report. For both the HF and LF arms, mean visual analog scale (VAS) scores for back and leg pain decreased significantly: 77% and 76%, respectively, for the HF arm and 64% and 64%, respectively, for the LF arm. In addition, most subjects experienced significant improvements in VAS, Oswestry Disability Index, European Quality of Life 5 Dimension questionnaire, Patient Global Impression of Change, and sleep duration.

Conclusions

These preliminary results demonstrate that WSCS devices can reduce FBSS chronic pain substantially with both LF and HF stimulation waveforms over a seven-month period (30-day trial period and six-month post-trial evaluation).
Modeling enamel matrix secretion in mammalian teeth
Authors: Häkkinen Teemu J. , Susanna Sova S. , Corfe Ian J. , Tjäderhane Leo , Hannukainen Antti , Jernvall Jukka
Published: January 2019

The most mineralized tissue of the mammalian body is tooth enamel. Especially in species with thick enamel, three-dimensional (3D) tomography data has shown that the distribution of enamel varies across the occlusal surface of the tooth crown. Differences in enamel thickness among species and within the tooth crown have been used to examine taxonomic affiliations, life history, and functional properties of teeth. Before becoming fully mineralized, enamel matrix is secreted on the top of a dentine template, and it remains to be explored how matrix thickness is spatially regulated. To provide a predictive framework to examine enamel distribution, we introduce a computational model of enamel matrix secretion that maps the dentine topography to the enamel surface topography. Starting from empirical enamel-dentine junctions, enamel matrix deposition is modeled as a diffusion-limited free boundary problem. Using laboratory microCT and synchrotron tomographic data of pig molars that have markedly different dentine and enamel surface topographies, we show how diffusion-limited matrix deposition accounts for both the process of matrix secretion and the final enamel distribution. Simulations reveal how concave and convex dentine features have distinct effects on enamel surface, thereby explaining why the enamel surface is not a straightforward extrapolation of the dentine template. Human molar simulations show that even subtle variation in dentine topography can be mapped to the enamel surface features. Mechanistic models of extracellular matrix deposition can be used to predict occlusal morphologies of teeth.