Search

Geolocated social media data provide a powerful source of information about places and regional human behavior. Because only a small amount of social media data have been geolocation‐annotated, inference techniques play a substantial role to increase the volume of annotated data. Conventional research in this area has been based on the text content of posts from a given user or the social network of the user, with some recent crossovers between the text‐ and network‐based approaches. This paper proposes a novel approach to categorize highly‐mentioned users (celebrities) into Local and Global types, and consequently use Local celebrities as location indicators. A label propagation algorithm is then used over the refined social network for geolocation inference. Finally, we propose a hybrid approach by merging a text‐based method as a back‐off strategy into our network‐based approach. Empirical experiments over three standard Twitter benchmark data sets demonstrate that our approach outperforms state‐of‐the‐art user geolocation methods. [ABSTRACT FROM AUTHOR]

A method for synthesis of high aspect ratio platelet seeds by growth of SrTiO3 on Sr3Ti2O7 core particles is reported. The aim of this study was to identify and control the morphology and size of SrTiO3 particles via molten salt synthesis. Platelet and tabular morphologies with rectangular faces were obtained using rutile and anatase, respectively. Platelet SrTiO3 particles with an edge length of 10–40 μm and a thickness of 1–4 μm were obtained. High aspect ratios (edge length to thickness) of 7–10 were measured for platelet particles as opposed to lower aspect ratios of 2–4 for tabular particles. Highly anisotropic platelets are suitable template candidates to achieve textured ceramics. [ABSTRACT FROM AUTHOR]

The magnetic moment (g‐factor) of the electron is a fundamental quantity in physics that can be measured with high accuracy by spectroscopy in Penning traps. Its value has been predicted by theory, both for the case of the free (unbound) electron and for the electron bound in a highly charged ion. Precision measurements of the electron magnetic moment yield a stringent test of these predictions and can in turn be used for a determination of fundamental constants such as the fine structure constant or the atomic mass of the electron. For the bound‐electron magnetic‐moment measurement, two complementary approaches exist, one via the so‐called "continuous Stern–Gerlach effect", applied to ions with zero‐spin nuclei, and one a spectroscopic approach, applied to ions with nonzero nuclear spin. Here, the latter approach is detailed, and an overview of the experiment and its status is given. [ABSTRACT FROM AUTHOR]

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by core symptoms including impairment in social communication and restrictive and repetitive behaviors and interests. Music has emerged in the past decade as an intervention therapy for children with ASD. The aim of the present study was to evaluate the effects of music on cognition impairments in the valproic acid (VPA) rat model of autism. The VPA was administered for animal modeling of autism on embryonic day 12.5 (E12.5) (600 mg/kg). Male and female pups were sub divided into four main groups (Saline.Non‐music, VPA.Non‐music, Saline.Music, and VPA.Music). The rats in the music groups were exposed to Mozart's piano sonata K.448 for 30 days (4 h/day), from postnatal day (PND) 21 to 50. Autistic‐like behaviors were tested using a social interaction, the Morris water maze (MWM), and a passive avoidance tasks at the end of the PND 50. Our results demonstrated that VPA‐exposed rat pups had significantly lower sociability and social memory performance compared with the saline‐exposed rats in both sexes. VPA‐exposed rat pups exhibited learning and memory impairments in the MWM and passive avoidance tasks. Our results demonstrated that music improved sociability in VPA‐exposed rats, especially in males. Furthermore, our findings revealed that music improved learning impairments in VPA‐exposed male rats in MWM task. In addition, music improved spatial memory impairments in VPA‐exposed rats of both sexes. We also found that music improved passive avoidance memory impairments in VPA‐exposed rats of both sexes, especially in females. More investigation in future studies are needed. [ABSTRACT FROM AUTHOR]

In this study, a combined ON/OFF and conformal mapping method is applied to the permanent magnet shape optimisation of the surface-mounted permanent magnet synchronous motor (SPMSM). The magnet shape has a profound impact on the cogging torque and torque profile of the SPMSM. The proposed method is based on the combination of the conformal mapping and ON/OFF methods, which can reduce computation time significantly as compared with methods that are based on the finite-element method (FEM). For the optimisation process, genetic algorithms are used and applied to three cases. Finally, the FEM is used to verify the magnetic model and characteristics of the optimised machine. [ABSTRACT FROM AUTHOR]

In this study, a combined ON/OFF and conformal mapping method is applied to the permanent magnet shape optimisation of the surface‐mounted permanent magnet synchronous[AQ ID=Q2] motor (SPMSM). The magnet shape has a profound impact on the cogging torque and torque profile of the SPMSM. The proposed method is based on the combination of the conformal mapping and ON/OFF methods, which can reduce computation time significantly as compared with methods that are based on the finite‐element method (FEM). For the optimisation process, genetic algorithms are used and applied to three cases. Finally, the FEM is used to verify the magnetic model and characteristics of the optimised machine. [ABSTRACT FROM AUTHOR]

The Oligocene Nasrand intrusive rocks (NIRs), located in the central part of the Urumieh–Dokhtar magmatic arc, are mainly composed of granite and subordinate diorite and gabbro. These rocks are characterized by the enrichment of light rare earth elements (LREEs), Nb‐Ta negative anomalies, and high LILE/HFSE, suggesting a subduction‐related origin. The felsic rocks with granite compositions have high SiO2 content (69.77–77.88 wt.%), low Mg# (0.02–0.43), low Nb/Ta, and Zr/Hf (Avg: 12.53, and 33.08, respectively). The initial 87Sr/86Sr ratio and εNd(t) values in felsic rocks range from 0.70577 to 0.70576 and 0.4 to −0.3, respectively. These data suggest that these felsic rocks originated from juvenile crust by heat rising from basaltic magmas in an orogenic setting. The mafic‐intermediate rocks and dikes are gabbro, gabbroic diorite, and monzodiorite, with low SiO2 content (48.08–56.11 wt.%) and high Mg# (0.37–0.68), with average ratios of Nb/Ta and Zr/Hf are 27.88 and 39.84, respectively. The initial 87Sr/86Sr ratio and εNd(t) values for mafic‐intermediate rocks and dikes are 0.70583 to 0.70476 and −0.1 to +2.6, respectively. These characteristics indicate magma from a mantle source that had undergone minor mixing with juvenile crust. It seems mantle‐derived juvenile magma underplating played an important role in the crustal growth in the Urumieh–Dokhtar magmatic belt during the Ediacaran to Early Cambrian, relative to other time frames. [ABSTRACT FROM AUTHOR]

A new fault diagnosis method for detecting the rotor eccentricity faults including static, dynamic and mixed eccentricity is proposed for brushless doubly‐fed induction machines (BDFIMs). BDFIMs are attractive alternatives for the conventional doubly‐fed induction generator (DFIG) for offshore wind power generation; therefore, paying attention to their fault detection is essential. Existing fault detection methods for conventional induction machines cannot be directly applied to the BDFIM due to its special rotor structure and stator winding configurations as well as complex magnetic field patterns. This article proposes a novel fault detection method based on motor current signal analysis to determine stator current harmonics, induced by the nested‐loop rotor slot harmonics (NRSHs), as fault indices. The analysis is performed under healthy conditions and with different types of rotor eccentricity. Finally, a sensitivity analysis is carried out to confirm the practicability of the proposed technique with various fault intensities and load conditions. Analytical winding function approach, finite element analysis and experimental tests on a prototype D180 BDFIM are used in this study to validate the proposed fault detection technique. [ABSTRACT FROM AUTHOR]

Once blackouts occur the system operators should re‐energise the affected system in the shortest time. To attain this, restoration plans should be developed beforehand. A deliberate restoration plan considers the supply duration of the cranking power to non‐black‐start units (NBSUs), besides the static and dynamic constraints of the power system. Hence, there should be a method to estimate the restoration duration of NBSUs considering the failure in breakers operating mechanism and the stochastic nature of restoration actions. Accordingly, in this study, generally distributed transition stochastic Petri net is employed to calculate the supply duration of NBSUs, critical loads and the execution time of restoration actions. This is significant because the planners can validate their restoration plans from the NBSUs critical times' point of view or determine energisation time of critical loads. The proposed method has been applied in three test cases, two of these are used for benchmarking, and the other one is a part of Iran bulk power system, which includes a real black‐start test. The results show the effectiveness of the method in estimating the restoration duration. [ABSTRACT FROM AUTHOR]

The Lower Cretaceous siliciclastic fluvial to shallow marine Shurijeh–Shatlyk formations together form one of the main reservoir successions in the Kopeh Dagh–Amu Darya Basin (NE Iran, Turkmenistan, and north of Afghanistan). Sedimentary facies and thickness changes in the Shurijeh–Shatlyk formations show complex variations throughout the basin, which highlight the importance of understanding the controlling factors on facies distribution and depositional setting for future hydrocarbon exploration. Integration of 3D seismic data, 13 boreholes, and five surface stratigraphic sections led to identification of lithofacies and facies associations. The results allow subdivision of this siliciclastic succession into four stratigraphic units (A, B, C, and D). Our study indicates that base‐level changes interacted with palaeotopography inherited from Middle Jurassic basin rifting, Upper Jurassic carbonate reefs/patch reef distributions, and reactivation of the deep basin faults, to control the Shurijeh–Shatlyk depositional setting and sedimentary facies distribution. Our findings show that the Aghdarband and Badkhyz–Maimana palaeo‐highs affected the Kopeh Dagh–Amu Darya Basin throughout deposition of the Shurijeh–Shatlyk formations. Allogeneic processes and active tectonics, related to the Valanginian Late Cimmerian Orogeny, caused a base‐level fall, exposure of Upper Jurassic carbonate sediments, and deposition of a carbonate pebbly conglomerate unit in the western part of the study area. This base‐level fall led to the deposition of thick evaporites in the western area and conglomerate in the eastern parts of the Kopeh Dagh. Due to a Hauterivian sea‐/base‐level rise, several deltas formed in the basin, which form the main reservoir zone in the Murgab Depression and Khangiran Field in Turkmenistan and Iran. [ABSTRACT FROM AUTHOR]

A method for the trace determination of cadmium ions in water, human urine and human blood serum samples using ultrasonic‐assisted dispersive micro‐solid‐phase extraction (UA‐D‐μSPE) was developed. Silica‐coated magnetic nanoparticles were coated with polythiophene, and the resulting sorbent was characterized using thermogravimetry, differential thermal analysis, scanning electron microscopy, Fourier transform infrared spectrometry and X‐ray diffraction. Following UA‐D‐μSPE, cadmium ions were quantified using graphite furnace atomic absorption spectrometry. A Box–Behnken design was used for optimization of important sorption and desorption parameters in UA‐D‐μSPE: in the sorption step, pH of solution, sorption amount and sonication time for sorption; in the desorption step, concentration of eluent, volume of eluent and sonication time. The optimum conditions for the method were: pH of solution, 7.5; sonication time for sorption, 3 min; sorption amount, 35 mg; type and concentration of eluent, HCl and 1.1 mol l−1; volume of eluent, 360 μl; sonication time for desorption, 110 s. Under the optimized conditions the limit of detection and relative standard deviation for the detection of cadmium ions by UA‐D‐μSPE were found to be 0.8 ng l−1 and <6%, respectively. [ABSTRACT FROM AUTHOR]

The Niyasar plutonic complex, one of the Cenozoic magmatic assemblages in the Urumieh-Dokhtar magmatic belt, was the subject of detailed petrographic and mineralogical investigations. The Niyasar magmatic complex is composed of Eocene to Oligocene mafic rocks and Miocene granitoids. Eleven samples, representing the major rock units in the Niyasar magmatic complex and contact aureole were chosen for mineral chemical studies and for estimation of the pressure, temperature, and oxygen fugacity conditions of mineral crystallization during emplacement of various magmatic bodies. The analyzed samples are composed of varying proportions of quartz, plagioclase, K-feldspar, hornblende, biotite, titanite, magnetite, apatite, zircon, garnet, and clinopyroxene. Application of the Al-in-hornblende barometer indicates pressures of around 0.2 to 0.4 kbar for the Eocene-Oligocene mafic bodies and around 0.5 to 1.7 kbar for the Miocene granitoids. Hornblende-plagioclase thermometry yields relatively low temperatures (661-780 °C), which probably reflect late stage re-equilibration of these minerals. The assemblage titanite-magnetite-quartz as well as hornblende composition were used to constrain the oxygen fugacity and H2O content during the crystallization of the parent magmas in the Miocene plutons. The results show that the Miocene granitoids crystallized from magmas with relatively high oxygen fugacity and high H2O content (~5 wt% H2O). The Miocene granitoids show similar range of oxygen fugacity, H2O contents and mineral chemical compositions, which indicate a common source for their magmas. Although the crystallization pressures of the Miocene plutons discriminate various categories of plutonic bodies emplaced at depths of about 5.7-6.5 km (Marfioun pluton), about 4.2 km (Ghalhar pluton) and 1.9-2.3 km (Poudalg pluton), they were later uplifted to the same level by vertical displacement of faults. The emplacement depths of the Niyasar plutons suggest that the central part of the Urumieh-Dokhtar magmatic belt has experienced an uplift rate of ca. 0.25-0.4 mm/yr from the Miocene onwards. [ABSTRACT FROM AUTHOR]