bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECT OF STATIC ECCENTRICITY AND STATOR INTER-TURN SHORT CIRCUIT COMPOSITE FAULT ON ROTOR VIBRATION CHARACTERISTICS OF GENERATOR
Authors: He Yu-Ling , Ke Meng-Qiang , Wang Fa-Lin , Tang Gui-Ji , Wan Shu-Ting
Published: April 2018

This paper investigates the radial rotor vibration characteristics under static air-gap eccentricity and stator inter-turn short circuit composite faults. The air-gap magnetic flux density is firstly deduced to obtain the unbalanced magnetic pull (UMP) on rotor. Then the rotor vibration characters, as well as the developing trend between the faulty parameters and the vibration amplitudes, are analyzed. Finally, the experiments are taken on a SDF-9 type simulating generator. It is shown that the radial deformation possibility, the 2nd, 4th, and 6th harmonic vibrations will be caused by the composite faults. Besides, the development of the inter-turn short circuit, the increment of the static eccentricity, and the rise of the exciting current will all get the deformation trend and the vibration amplitudes increased.
POD ANALYSIS OF THREE-DIMENSIONAL HARMONICALLY FORCED WAKE FLOW OF A CIRCULAR CYLINDER
Authors: Nabatian Negar , Xu Xiaofei , Mureithi Njuki
Published: April 2018

A 3D numerical simulation of a circular cylinder wake is presented in this paper. The cylinder is harmonically forced in the stream-wise direction. The objective of the present work is to investigate the effect of the oscillation amplitude on the secondary transition of the wake. The frequency of the lift force is then linked to the form of the vortex shedding mode. The relation between these vortex shedding modes using POD analysis of the transverse velocity and the unsteady lift coefficient of 3D simulation is in good agreement with the 2D model. Results show that the 3D spanwise effect, which can change the wake structure, is suppressed at Re = 200 by streamwise oscillation of the cylinder. Thus the 2D analysis can effectively model the temporal instability of the wake flow.
A NUMERICAL APPROACH TO CALCULATE CREEP IN ROLLER FOLLOWER VALVE TRAIN BASING ON FRICTION AND LUBRICATION MODELING
Authors: Khurram Muhammad , Mufti Riaz Ahmad , Bhutta Muhammad Usman , Habib Yousaf , Ahmed Arslan , Afzal Naqash
Published: April 2018

A numerical approach basing on friction and lubrication analysis has been developed to determine the creep at cam/roller interface in end pivoted roller finger follower valve train. The kinematic and dynamic analysis at the geometrical mating surfaces of cam and roller follower has been carried out to predict the required instantaneous motion parameters and normal loading whereas the oil film thickness is determined using lubrication analysis. The tangential forces have been computed precisely using elastohydrodynamic and mixed lubrication concept for a complete cam cycle. At low camshaft operating speeds, the creep proves to be low whereas the creep increases significantly under the influence of high tangential loading at higher operating speeds.
COMPARISON OF EXPERIMENTALLY MEASURED AND SIMULATED WORKPIECE AND GRINDING WHEEL TOPOGRAPHY USING A NEW DRESSING MODEL
Authors: Darafon Abdalslam , Warkentin Andrew , Bauer Robert
Published: April 2018

This paper presents a new empirical model of the dressing process in grinding which is then incorporated into a 3D metal removal computer simulator to numerically predict the ground surface of a workpiece as well as the dressed surface of the grinding wheel. The proposed model superimposes a ductile cutting dressing model with a grain fracture model to numerically generate the resulting grinding wheel topography and workpiece surface. Grinding experiments were carried out using “fine”, “medium” and “coarse” dressing conditions to validate both the predicted wheel topography as well as the workpiece surface finish. For the grinding conditions used in this research, it was observed that the proposed dressing model is able to accurately predict the resulting workpiece surface finish for all dressing conditions tested. Furthermore, similar trends were observed between the predicted and experimentally-measured grinding wheel topographies when plotting the cutting edge density, average cutting edge width and average cutting edge spacing as a function of depth for all dressing conditions tested.
PERFORMANCE ANALYSIS OF A THERMOELECTRIC POWER GENERATOR UNDER VOLUMETRIC CONSTRAINT
Authors: Sahin Ahmet Z. , Yilbas Bekir S.
Published: April 2018

The efficiency of a thermoelectric power generator can be optimized through proper sizing of the device geometric configurations. In the present study, pin length optimization of the thermoelectric generator for a fixed total pin volume is carried out and the pin length maximizing the device efficiency is formulated. The influences of temperature ratio, defined as the upper junction temperature divided by the lower junction temperature, and the figure of merit, defined as Z = α2/KR, on the device efficiency and output power operating at the optimum pin length are examined. It is found that a unique temperature ratio exists which maximizes the efficiency of the thermoelectric device with the optimum pin length.
MULTI-OBJECTIVE OPTIMIZATION OF TURNING PARAMETERS USING THE COMBINED MOORA AND ENTROPY METHOD
Authors: Singaravel B. , Selvaraj T. , Vinodh S.
Published: April 2018

Selection of optimum machining parameters in machining operations leads to good functional attributes for the machined components and increased productivity. In this work, machining parameters and nose radius are optimized in turning of EN25 steel with coated carbide tool by the application of combined Multi-Objective Optimization by Ratio Analysis (MOORA) and entropy measurement method. The selected machining parameters are cutting speed, feed rate, depth of cut and nose radius for minimization of surface roughness, micro-hardness and maximization of Material Removal Rate (MRR). Entropy concept has been used to assign the weight criteria of each objective being considered. The optimum combination of machining parameters and nose radius are obtained using normalized assessment values. The results obtained in the analysis are validated and the results based on turning process responses can be effectively improved.
ENERGY HARVESTING USING A NONLINEAR VIBRATION ABSORBER
Authors: Zhang Yu , De Rosa Riccardo , Zhang Jingyi , Alameri Mariam , Liu Kefu
Published: April 2018

In this study, an energy harvesting device based on a nonlinear vibration absorber is developed to achieve two objectives: vibration suppression and energy harvesting in a wideband manner. First, the proposed design is described. Next, the system modeling is addressed. The parameter characterization is presented. Then, the performance of the nonlinear vibration absorber is tested by sweeping harmonic excitation. The testing results have shown that the device can suppress vibration and convert vibration energy into electric energy in a broadband manner.
DESIGN OF A SPHERICAL CAM-ROLLER MECHANISM FOR AN AUTOMOTIVE DIFFERENTIAL
Authors: Chaudhary Mayank , Angeles Jorge , Morozov Alexei
Published: April 2018

Spherical cam-follower mechanisms are attractive alternatives to bevel gears, as they provide low backlash and low friction losses. The design of such a mechanism is reported here, to be incorporated in an automotive differential, whose bevel pinions and side gears are substituted by spherical cams and rollercarriers, respectively. Critical to the design of cam mechanisms is the generation of the cam-profile, free of undercutting. The profile, generated using computer algebra, is analyzed for singularities, including cusps and double points. The pressure angle, an important factor that governs the effective force transmission of cam mechanisms, is duly kept within acceptable limits. Conclusions are drawn on the suitability of cam mechanism developed for automotive applications.
MECHANICAL FAULT RECOGNITION RESEARCH BASED ON LMD-LSSVM
Authors: Dong Zengshou , Ren Zhaojing , Dong You
Published: April 2018

Mechanical fault vibration signals are non-stationary, which causes system instability. The traditional methods are difficult to accurately extract fault information and this paper proposes a local mean decomposition and least squares support vector machine fault identification method. The article introduces waveform matching to solve the original features of signals at the endpoints, using linear interpolation to get local mean and envelope function, then obtain production function PF vector through making use of the local mean decomposition. The energy entropy of PF vector take as identification input vectors. These vectors are respectively inputted BP neural networks, support vector machines, least squares support vector machines to identify faults. Experimental result show that the accuracy of least squares support vector machine with higher classification accuracy has been improved.
DYNAMICS ANALYSIS, SELECTION AND CALCULATION ON THE PARAMETERS OF A ROTARY VIBRATING SCREEN
Authors: Jiang Jing , Liu Shuying , Wen Bangchun
Published: April 2018

This paper introduces the structural characteristics and screening principle of rotary vibrating screen, and establishes nonlinear equations of rotary vibrating screen in view of the material effects. An approximate solution, material combination coefficient, and material drag coefficient for the nonlinear equations are solved by equivalent linearization method based on nonlinear theory. The selection and calculation on main parameters and a practical calculation example are carried out. It is of guiding significance and reference value for the design of this kind of machinery.
NUMERICAL SIMULATION ON THE EXISTENCE OF FLUCTUATION OF INSTANTANEOUS AVAILABILITY
Authors: Yi Yang , Chao Ren Si , Guimei Fan , Rui Kang
Published: April 2018

This paper considers the fluctuation of the instantaneous availability by numerical methods for a one-unit repairable system. The choices of the failure rate and repair rate are linear or cubic increasing functions. For the equation of instantaneous availability composing of two convolutions, the following numerical methods are used: the composite Simpson formula and the trapezoidal formula. That is to say, the simulated curves of instantaneous availability under any condition are obtained. Through the simulated results, when the failure rate and repair rate are selected as increasing functions, the extremum of simulated curve exists so fluctuation exists. On the other hand, if parameters of increasing functions become smaller, the fluctuation weakens.
PERFORMANCE INVESTIGATION OF AN SI ENGINE WITH VARIABLE VALVE TIMING AND LIFT BASED ON A MAGNETO-RHEOLOGICAL VALVE
Authors: Shiao Yaojung , Cheng Wen-Hsin
Published: April 2018

Cylinder valve with variable timing and variable lift is a potential technology to improve engine performance. This research studied cylinder dynamics of a spark-ignition (SI) engine equipped with a new full variable valve system (VVS) based on an innovated magneto-rheological (MR) technology. An MR valve block was combined with a conventional inlet valve in this MR VVS. The study obtained many patterns of valve opening/closing by controlling current to the MR VVS, which controlled the MR fluid flowing through magnetic plate block. Magnetic simulations were performed for the new MR VVS to investigate the relationships among MR valve displacement, valve lift, and valve timing. Simulation results showed that the MR VVS provided high degrees of freedom of valve timing and lift for gasoline engine to produce different torque modes and high engine efficiency. The abilities of this MR VVS to become essential technique of high-efficiency engine were confirmed in the results.
THE DEVELOPMENT OF TILT-ROTOR UNMANNED AERIAL VEHICLE
Authors: Zou Jie-Tong , Zheng-Yan Pan
Published: April 2018

In this research, we had developed quad-rotor unmanned aerial vehicles with the tilt-rotor mechanism. People are eager to fly therefore the development of aerial vehicles, such as fixed-wing aerial vehicles and multi-rotor aerial vehicles, has grown rapidly in recent years. The multi-rotor vertical take-off and landing (VTOL) unmanned aerial vehicle which can fly stably and hover in a fix position developed the fastest. Comparing the general fixed-wing aircrafts and rotorcrafts, fixed-wing aircrafts can fly with a higher speed than rotorcrafts, but they do not have the VTOL and hovering abilities. The proposed quad-rotor aerial vehicle with tilt-rotor mechanism has two flight modes: rotorcraft and fixed-wing aircraft flight mode. It can take-off and land vertically in rotorcraft mode and can also fly faster in fixed-wing aircraft flight mode. The dynamic equations of the proposed quad-rotor aerial vehicle with tiltrotor mechanism are also studied in this paper.
GLASS CUTTING WITH ELONGATION OPTICS IN COMPARISON TO CONVENTIONAL METHODS BY LASER
Authors: Wu Shih-Jeh , Hsu Hsiang-Chen , Lin Wen-Fei
Published: April 2018

In this study, the authors applied a pico-second 532 nm laser with state of art elongated optics on cutting soda lime glasses and compared the results with three other methods by conventional focusing technique namely; dice-and break, direct wobbling cut (both by UV laser), and stealth cut (by pico-second IR laser). The dice-and-break method has the fastest speed, however, the roughness is poor. The wobbling method is poor in both roughness and cutting speed. The dual-focused beam has the smoothest cross-section with fast speed in one step. Of the four methods, the elongation optics has the best overall performance. The improved quality attributes to a well-managed energy distribution.
INVESTIGATION OF THE ELECTRODE DESIGN OF A SINGLE-MODE PIEZOELECTRIC ACTUATOR
Authors: Chang Shyang-Jye , Hsieh Zheng-Yang
Published: April 2018

This study investigated the electrode design and output performance of a single-mode piezoelectric actuator. The relevance between the design parameters of the electrode and the vibration amplitude of the friction element was determined. Two split electrode design methods, horizontal and vertical, were investigated. The Taguchi method was used to investigate the relevance of the exciter electrodes and the vibration amplitude of the piezoelectric actuator. The simulation experiments demonstrated that the vertical split electrode design can be used to adjust the Y vibration amplitude. The thrust force measurement demonstrated that the thrust force of the piezoelectric actuator can be adjusted by using the split electrode design.
THE ENGINEERING DESIGN AND TRANSMISSION EFFICIENCY VERIFICATION OF HELICAL SPUR GEAR TRANSMISSION WITH A SINGLE GEAR PAIR
Authors: Hsieh Long-Chang , Chen Tzu-Hsia
Published: April 2018

The transmission efficiency of a gear reducer (ηT) can be expressed as ηT = ηm × ηb × ηs, where ηm is the meshing efficiency of gear pairs, ηb is the efficiency of bearings, and ηs is efficiency of oil seals. Based on the research of Hsieh, et al., the meshing efficiencies of a helical spur gear pair (4, 77) are between 96.13 and 99.20%. The purpose of this article is to analyze the theoretical transmission efficiencies of non-standard helical spur gear pair and verify the theorem. According to the gear data, the theoretical transmission efficiencies are calculated to be 90.13–97.85%. And its test values of transmission efficiencies are between 82.3 and 91.9% (acceptable values). There are only 5.39–14.14% errors between these two values. This manuscript verifies that a helical spur gear pair can have a high reduction ratio (20–30) and acceptable real transmission efficiencies.
Inclined landing testing of an omni-directional unmanned aerial vehicle
Authors: von Frankenberg Florentin , Nokleby Scott B.
Published: April 2018

Traditional multi-rotors and helicopters control translational movement by changing the orientation of the entire vehicle. This approach limits the effectiveness of these vehicles in applications — such as a mobile manipulator base — in which it is often necessary to fly near large structures where unpredictable aerodynamic conditions exist. Maintaining precise control of position requires counteracting disturbance forces quickly. Having to roll and pitch the entire vehicle induces a delay that limits the ability of traditional multi-rotors and helicopters to maintain position precisely. Additionally, a mobile base must be capable of resisting arbitrary combinations of force and torque resulting from use of a manipulator arm. Traditional multi-rotors and helicopters do not have this ability. This paper presents a novel unmanned aerial vehicle (UAV) concept that features the addition of four rotors orthogonal to the main lift rotors of a traditional quadrotor design. These rotors allow decoupling of orientation from translational movement. Tests done on a physical prototype demonstrated the ability to sustain roll or pitch angles up to 15° independent of translational movement, including the ability to move backwards at an angle and to dock on inclined surfaces in a controlled manner. The tests show that the OmniCopter can successfully land on surfaces with up to 30° inclination. This type of motion is impossible for a traditional multi-rotor vehicle.
Influence of design parameters on the singularities and workspace of a 3-R

P

S parallel robot
Authors: Jha Ranjan , Chablat Damien , Baron Luc
Published: April 2018

This paper presents variations in the workspace, singularities, and joint space with respect to design parameter k, which is the ratio of the dimensions of the mobile platform to the dimensions of the base of a 3-RPS parallel manipulator. The influence of the design parameters on parasitic motion, which is important when selecting a manipulator for a desired task, is also studied. The cylindrical algebraic decomposition method and Gröbner-based computations are used to model the workspace and joint space with parallel singularities in 2R1T (two rotational and one translational) and 3T (three translational) projection spaces, where the orientation of the mobile platform is represented using quaternions. These computations are useful in selecting the optimum value for the design parameter k such that the parasitic motions can be limited to specific values. Three designs of the 3-RPS parallel robot, based on different values of k, are analyzed.
Pressure effect on the structural, phonon, elastic and thermodynamic properties of L12phase RH3TA: First-principles calculations
Authors: Wang Leini , Jian Zhang , Ning Wei
Published: April 2018

The phonon, elastic and thermodynamic properties of L12phase Rh3Ta have been investigated by the density functional theory (DFT) approach combined with the quasi-harmonic approximation model. The results of the phonon band structure show that L12phase Rh3Ta possesses dynamical stability in the pressure range from 0–80 GPa due to the absence of imaginary frequencies. The pressure dependences with the elastic constants C[Formula: see text], shear modulus G, bulk modulus B, Young’s modulus Y, Poisson’s ratio and B/G ratio have been analyzed. The results of the elastic properties studies show that L12phase Rh3Ta compound is mechanically stable and possesses a higher hardness, improved ductility and plasticity under higher pressures. The pressure and temperature relationship of the thermodynamic properties, such as the Debye temperature [Formula: see text], heat capacity C[Formula: see text], thermal expansion coefficient [Formula: see text] and the Grüneisen parameter [Formula: see text] are predicted by the quasi-harmonic Debye model in a wide pressure (0–80 GPa) and temperature (0–750 K) ranges.
Converting pulsating dissipative optical solitons into fixed-shape pulses
Authors: Latas Sofia C. V. , Ferreira Mário F. S.
Published: April 2018

The complex Ginzburg–Landau equation is solved numerically and three types of pulsating pulses are obtained: plain pulsating, erupting, and creeping solitons. We discuss the main characteristics of these pulses and demonstrate the possibility of converting them into fixed-shape pulses under the influence of some higher-order effects.
Molybdenum disulfide saturable absorber for eye-safe mode-locked fiber laser generation
Authors: Latiff A. A. , Cheng X. S. , Rusdi M. F. M. , Paul M. C. , Harun S. W. , Ahmad H.
Published: April 2018

We demonstrated an all-fiber mode-locked Thulium–Holmium co-doped fiber laser (THDFL) based on molybdenum disulfide (MoS2) tape saturable absorber. The THDFL generates a mode-locked pulse in anomalous regime at 1,979[Formula: see text]nm using 5[Formula: see text]m long Thulium–Holmium co-doped (THDF) as a gain medium. Through mechanical exfoliation method, the MoS2 was mechanically extracted from a commercial MoS2 crystal by using a clear scotch tape. Through balanced twin-detector measurement, the obtained MoS2 tape has a nonlinear absorption of 10% with 100[Formula: see text]MW/cm2 saturation intensity. Under 775[Formula: see text]mW to 852[Formula: see text]mW pump power, a stable pulse train was obtained at 9.12[Formula: see text]MHz repetition rate with a signal-to-noise ratio (SNR) of 45[Formula: see text]dB. The maximum output power and pulse energy were measured about 20[Formula: see text]mW and 2.2[Formula: see text]nJ, respectively. With a 3-dB spectral bandwidth of 2.1[Formula: see text]nm, the minimum possible pulse width was determined as 1.97[Formula: see text]ps.
Full idempotents in Leavitt path algebras
Authors: Emre Ekrem
Published: April 2018

We give necessary and sufficient conditions on a directed graph [Formula: see text] for which the associated Leavit path algebra [Formula: see text] has at least one full idempotent. Also, we define [Formula: see text] sub-graphs of [Formula: see text] and show that [Formula: see text] has at least one full idempotent if and only if there is a sub-graph [Formula: see text] such that the associated Leavitt path algebra [Formula: see text] has at least one full idempotent.
Several classes of permutation trinomials from Niho exponents over finite fields of characteristic 3
Authors: Liu Qian , Sun Yujuan
Published: April 2018

Permutation polynomials have important applications in cryptography, coding theory, combinatorial designs, and other areas of mathematics and engineering. Finding new classes of permutation polynomials is therefore an interesting subject of study. Permutation trinomials attract people’s interest due to their simple algebraic forms and additional extraordinary properties. In this paper, based on a seventh-degree and a fifth-degree Dickson polynomial over the finite field [Formula: see text], two conjectures on permutation trinomials over [Formula: see text] presented recently by Li–Qu–Li–Fu are partially settled, where [Formula: see text] is a positive integer.
The boundedness of a weighted Coxeter group with non-3-edge-labeling graph
Authors: Li Yan , Shi Jian-Yi
Published: April 2018

Let [Formula: see text] be a weighted Coxeter group such that the order [Formula: see text] of the product [Formula: see text] is not 3 for any [Formula: see text] and that [Formula: see text], where [Formula: see text] is the longest element in the parabolic subgroup [Formula: see text] of [Formula: see text] generated by [Formula: see text]. We prove that [Formula: see text] is bounded with [Formula: see text] an upper bound in the sense of Lusztig in Sec. 13.2 of [Hecke Algebras with Unequal Parameters, arXiv:math/0208154 v2 [math.RT] 10 Jun 2014], verifying a conjecture of Lusztig in our case (see Conjecture 13.4 in loc. cite).
Entanglement witnesses for families of the bound entangled three-qubit states
Authors: Akbari-Kourbolagh Y. , Azhdargalam M.
Published: April 2018

Entanglement witnesses are of special interest for distinguishing between separable and entangled states. For three-qubit states, a family of optimal entanglement witnesses has been introduced by Jafarizadeh et al. [Eur. Phys. J. D 50 (2008) 107]. We give an alternative demonstration for some elements of this family and show that they are able to detect bound entangled states. To illustrate this fact, we consider two families of bound entangled three-qubit states, introduced by Kay [Phys. Rev. A 83 (2011) 020303] and Kye [J. Phys. A, Math. Theor. 48 (2015) 235303], and show that these witnesses detect the entanglement of all states of these two families.
Impulsive Waves Generated by the Collapse of a Submerged Granular Column: A Three-Phase Flow Simulation with an Emphasis on the Effects of Initial Packing Condition
Authors: Yu Ming-Lan , Lee Cheng-Hsien , Huang Zhenhua
Published: April 2018

Submarine landslides are one of the major causes of tsunamis but less understood due to complicated dynamics involved and the lack of observational data. In this study, the collapse of a submerged granular column is used as an idealized submarine landslide model. A three-phase (solid–liquid–gas) continuum model is used to study the effect of the column’s initial packing on the collapse process and the resultant waves. Numerical simulations reveal that the initial packing can have significant effect on the duration of the collapse process and the characteristics of the resultant waves. Pore pressure, velocity field of the fluid phase, the volume of the sliding granular mass, and the sliding velocity are calculated and used to understand the effects of initial packing condition. Our results show that it is important to consider the initial packing effects in numerical simulations of submarine landslides and the resultant waves. Our result also show that the large vortex generated by the moving front of the granular flow can affect the form of the waves generated by the landslide.
Divisor graph of the complement of Γ(R)
Authors: Kumar Ravindra , Prakash Om
Published: April 2018

Let [Formula: see text] be the complement of the zero-divisor graph of a finite commutative ring [Formula: see text]. In this paper, we provide the answer of the question (ii) raised by Osba and Alkam in [11] and prove that [Formula: see text] is a divisor graph if [Formula: see text] is a local ring. It is shown that when [Formula: see text] is a product of two local rings, then [Formula: see text] is a divisor graph if one of them is an integral domain. Further, if [Formula: see text], then [Formula: see text] is a divisor graph.
Continuity of h-convex functions
Authors: Rostamian Delavar M. , Dragomir S. S.
Published: April 2018

In this paper, a condition which implies the continuity of an [Formula: see text]-convex function is investigated. In fact, any [Formula: see text]-convex function bounded from above is continuous if the function [Formula: see text] satisfies a certain condition which is called pre-continuity condition.
Inequalities for relative operator entropy in terms of Tsallis’ entropy
Authors: Dragomir S. S.
Published: April 2018

In this paper, we obtain new inequalities for relative operator entropy [Formula: see text] in terms of Tsallis’ relative entropy [Formula: see text] [Formula: see text] in the case of positive invertible operators [Formula: see text] [Formula: see text]. Further bounds for [Formula: see text] are also provided.
South China Sea crustal thickness and oceanic lithosphere distribution from satellite gravity inversion
Authors: Gozzard Simon , Kusznir Nick , Franke Dieter , Cullen Andrew , Reemst Paul , Henstra Gijs
Published: April 2018

Inversion of satellite-derived free-air gravity-anomaly data has been used to map crustal thickness and continental lithosphere thinning in the South China Sea. Using this, we determine the ocean–continent transition zone structure, the distal extent of continental crust, and the distribution of oceanic lithosphere and continental fragments in the South China Sea. We construct a set of regional crustal cross-sections, with Moho depth from gravity inversion, spanning the South China Sea from offshore China and Vietnam to offshore Malaysia, Brunei and the Philippines to examine variations in ocean–continent transition structure and ocean-basin width. Our analysis shows a highly asymmetrical conjugate margin structure. The Palawan margin shows a narrow transition from continental to oceanic crust. In contrast, the conjugate northern margin of the South China Sea shows a wide region of thinned continental crust and an isolated block of continental crust (the Macclesfield Bank) separated from the Chinese margin by a failed oceanic rift. The Dangerous Grounds are predicted to be underlain by fragmented blocks of thinned continental crust. We use maps of crustal thickness and continental lithosphere thinning from gravity inversion together with free-air gravity- and magnetic-anomaly data to identify structural trends and to show that rifting and the early seafloor-spreading axis had an ENE–WSW trend while the later seafloor-spreading axis had a NE–SW trend.
Miocene UHT granulites from Seram, eastern Indonesia: a geochronological–REE study of zircon, monazite and garnet
Authors: Pownall J. M. , Armstrong R. A. , Williams I. S. , Thirlwall M. F. , Manning C. J. , Hall R.
Published: April 2018

The island of Seram, eastern Indonesia, incorporates Miocene ultrahigh-temperature (UHT; >900°C) garnet–sillimanite granulites that formed by extensional exhumation of hot mantle rocks behind the rolling-back Banda Arc. UHT metamorphic conditions are supported by new Zr-in-rutile thermometry results and the Miocene age of the UHT event is confirmed by closely-matched heavy rare earth element (HREE) abundances between garnet and
c.
16 Ma zircon. Monazites also record identical U–Pb ages, within uncertainty. However, these geochronometers do not date peak UHT metamorphism; instead, they date retrograde, garnet-consuming (Zr- and rare earth element (REE)-liberating) reactions that produced the granulites’ post-peak cordierite + spinel reaction microstructures. Zircons shielded within garnet did not crystallize
c.
16 Ma rims and so were unaffected by the entire UHT event. Miocene UHT metamorphism overprinted a Late Triassic–Early Jurassic upper-amphibolite facies event that grew garnet cores and 216–173 Ma zircon. In the Miocene, these garnet cores were overgrown by peritectic garnet rims during UHT metamorphism, with some rutiles recording
c.
900°C Zr-in-rutile temperatures. Garnet Lu–Hf ages of 138 Ma – produced by core–rim mixing – demonstrate that a component of Hf
4+
produced since
c.
200 Ma was retained through the
c.
16 Ma UHT event. Accordingly, UHT conditions must have been very short-lived and exhumation of the granulite complex very rapid.
Ursodeoxycholic acid protects against intestinal barrier breakdown by promoting enterocyte migration via EGFR- and COX-2-dependent mechanisms
Authors: Golden Jamie M. , Escobar Oswaldo H. , Nguyen Michelle V. L. , Mallicote Michael U. , Kavarian Patil , Frey Mark R. , Gayer Christopher P.
Published: April 2018

The intestinal barrier is often disrupted in disease states, and intestinal barrier failure leads to sepsis. Ursodeoxycholic acid (UDCA) is a bile acid that may protect the intestinal barrier. We hypothesized that UDCA would protect the intestinal epithelium in injury models. To test this hypothesis, we utilized an in vitro wound-healing assay and a mouse model of intestinal barrier injury. We found that UDCA stimulates intestinal epithelial cell migration in vitro, and this migration was blocked by inhibition of cyclooxygenase 2 (COX-2), epidermal growth factor receptor (EGFR), or ERK. Furthermore, UDCA stimulated both COX-2 induction and EGFR phosphorylation. In vivo UDCA protected the intestinal barrier from LPS-induced injury as measured by FITC dextran leakage into the serum. Using 5-bromo-2′-deoxyuridine and 5-ethynyl-2′-deoxyuridine injections, we found that UDCA stimulated intestinal epithelial cell migration in these animals. These effects were blocked with either administration of Rofecoxib, a COX-2 inhibitor, or in EGFR-dominant negative Velvet mice, wherein UDCA had no effect on LPS-induced injury. Finally, we found increased COX-2 and phosphorylated ERK levels in LPS animals also treated with UDCA. Taken together, these data suggest that UDCA can stimulate intestinal epithelial cell migration and protect against acute intestinal injury via an EGFR- and COX-2-dependent mechanism. UDCA may be an effective treatment to prevent the early onset of gut-origin sepsis.

NEW & NOTEWORTHY In this study, we show that the secondary bile acid ursodeoxycholic acid stimulates intestinal epithelial cell migration after cellular injury and also protects the intestinal barrier in an acute rodent injury model, neither of which has been previously reported. These effects are dependent on epidermal growth factor receptor activation and downstream cyclooxygenase 2 upregulation in the small intestine. This provides a potential treatment for acute, gut-origin sepsis as seen in diseases such as necrotizing enterocolitis.
NADPH oxidase 4-derived superoxide mediates flow-stimulated NKCC2 activity in thick ascending limbs
Authors: Saez Fara , Hong Nancy J. , Garvin Jeffrey L.
Published: April 2018

Luminal flow augments Na+ reabsorption in the thick ascending limb more than can be explained by increased ion delivery. This segment reabsorbs 30% of the filtered load of Na+, playing a key role in its homeostasis. Whether flow elevations enhance Na+-K+-2Cl− cotransporter (NKCC2) activity and the second messenger involved are unknown. We hypothesized that raising luminal flow augments NKCC2 activity by enhancing superoxide ([Formula: see text]) production by NADPH oxidase 4 (NOX4). NKCC2 activity was measured in thick ascending limbs perfused at either 5 or 20 nl/min with and without inhibitors of [Formula: see text] production. Raising luminal flow from 5 to 20 nl/min enhanced NKCC2 activity from 4.8 ± 0.9 to 6.3 ± 1.2 arbitrary fluorescent units (AFU)/s. Maintaining flow at 5 nl/min did not alter NKCC2 activity. The superoxide dismutase mimetic manganese (III) tetrakis (4-benzoic acid) porphyrin chloride blunted NKCC2 activity from 3.5 ± 0.4 to 2.5 ± 0.2 AFU/s when flow was 20 nl/min but not 5 nl/min. When flow was 20 nl/min, NKCC2 activity showed no change with time. The selective NOX1/4 inhibitor GKT-137831 blunted NKCC2 activity when thick ascending limbs were perfused at 20 nl/min from 7.2 ± 1.1 to 4.5 ± 0.8 AFU/s but not at 5 nl/min. The inhibitor also prevented luminal flow from elevating [Formula: see text] production. Allopurinol, a xanthine oxidase inhibitor, had no effect on NKCC2 activity when flow was 20 nl/min. Tetanus toxin prevents flow-induced stimulation of NKCC2 activity. We conclude that elevations in luminal flow enhance NaCl reabsorption in thick ascending limbs by stimulating NKCC2 via NOX4 activation and increased [Formula: see text]. NKCC2 activation is primarily the result of insertion of new transporters in the membrane.
Diaphragm plasticity in aging and disease: therapies for muscle weakness go from strength to strength
Authors: Greising Sarah M. , Ottenheijm Coen A. C. , O’Halloran Ken D. , Barreiro Esther
Published: April 2018

The diaphragm is the main inspiratory muscle and is required to be highly active throughout the life span. The diaphragm muscle must be able to produce and sustain various behaviors that range from ventilatory to nonventilatory such as those required for airway maintenance and clearance. Throughout the life span various circumstances and conditions may affect the ability of the diaphragm muscle to generate requisite forces, and in turn the diaphragm muscle may undergo significant weakness and dysfunction. For example, hypoxic stress, critical illness, cancer cachexia, chronic obstructive pulmonary disorder, and age-related sarcopenia all represent conditions in which significant diaphragm muscle dysfunction exits. This perspective review article presents several interesting topics involving diaphragm plasticity in aging and disease that were presented at the International Union of Physiological Sciences Conference in 2017. This review seeks to maximize the broad and collective research impact on diaphragm muscle dysfunction in the search for transformative treatment approaches to improve the diaphragm muscle health during aging and disease.
Performance Analysis of Dual-Polarized Massive MIMO System with Human-Care IoT Devices for Cellular Networks
Authors: Hong Jun-Ki
Published: April 2018

The performance analysis of the dual-polarized massive multiple-input multiple-output (MIMO) system with Internet of things (IoT) devices is studied when outdoor human-care IoT devices are connected to a cellular network via a dual-polarized massive MIMO system. The research background of the performance analysis of dual-polarized massive MIMO system with IoT devices is that recently the data usage of outdoor human-care IoT devices has increased. Therefore, the outdoor human-care IoT devices are necessary to connect with 5G cellular networks which can expect 1000 times higher performance compared with 4G cellular networks. Moreover, in order to guarantee the safety of the patient for emergency cases, a human-care Iot device must be connected to cellular networks which offer more stable communication for outdoors compared to short-range communication technologies such as Wi-Fi, Zigbee, and Bluetooth. To analyze the performance of the dual-polarized massive MIMO system for human-care IoT devices, a dual-polarized MIMO spatial channel model (SCM) is proposed which considers depolarization effect between the dual-polarized transmit-antennas and the receive-antennas. The simulation results show that the performance of the dual-polarized massive MIMO system is improved about 16% to 92% for 20 to 150 IoT devices compared to conventional single-polarized massive MIMO system for identical size of the transmit array.
Impact Analysis of Travel Time Uncertainty on AGV Catch-Up Conflict and the Associated Dynamic Adjustment
Authors: Li Jun-jun , Xu Bo-wei , Postolache Octavian , Yang Yong-sheng , Wu Hua-feng
Published: April 2018

In automated logistics systems, travel time uncertainty can severely affect automated guided vehicle (AGV) conflict and path planning. Insight is required into how travel time uncertainty affects catch-up conflict, the main AGV conflict in one-way road networks. Under normal circumstances, the probability formula for catch-up conflict is deduced based on an analysis of AGV catch-up conflict. The vertex, monotonicity, and symmetry of catch-up conflict probabilities are developed, for symmetrical AGV travel time distribution densities. A dynamic adjustment method based on conflict probability for AGVs is designed. The probability features of catch-up conflicts and the performance of the associated dynamic adjustment are simulated and validated for AGVs at an automated container terminal. The simulation results show that the impact analysis of travel time uncertainty on AGV catch-up conflict is correct, and the dynamic adjustment is effective.
Efficacy of Aloe vera, Ananas comosus, and Sansevieria masoniana Cream on the Skin Wound Infected with MRSA
Authors: Prakoso Yos Adi , Setiyo Rini Chylen , Wirjaatmadja Roeswandono
Published: April 2018

The tropical area has a lot of herbal medicines such as Aloe vera (AV), Ananas comosus (AC), and Sansevieria masoniana (SM). All the three have a unique potential effect as an antibacterial and wound-healing promoter. The aim of this study is to explore the role of AV, AC, and SM on the skin wound infected with methicillin-resistant Staphylococcus aureus (MRSA). Forty-five adult female Sprague Dawley rats weighing 250–300 grams were divided into 5 groups. All the groups were exposed to two round full-thickness punch biopsy and infected with MRSA. The group C was the control group/untreated; group BC was treated with base cream/without extract; group AV was treated with 75% AV cream; group AC was treated with 75% AC cream, and group SM was treated with 75% SM cream. The wounds were observed on days 5, 10, and 15. The healing of skin wounds was measured by a percentage of closure, skin tensile strength, and histopathology. The result showed that AV, AC, and SM have a similar potential effect on healing in the wound that was infected with MRSA compared to the groups C and BC (P<0.05). It shows that all the three herbal formulations can be used as the alternative therapy to the wound infected with MRSA.
Chiral All-Dielectric Metasurface Based on Elliptic Resonators with Circular Dichroism Behavior
Authors: Yahyaoui Ali , Rmili Hatem
Published: April 2018

We present the design of a new microwave all-dielectric chiral metasurface with circular dichroism behavior based on elliptic dielectric resonators (EDRs). During the design procedure, we have first optimized numerically the effects of the main design parameters such as the resonator’s size and orientation, as well as the size of the slot within them, on the metasurface transmission over the frequency band 10–20 GHz. Measurements on the final metasurface prototype have shown a large circular dichroism (Δ=0.61 and Δ=0.5) over two bands (17.55–17.61 GHz and 17.91–18.05 GHz) with ellipticities close to 45° which means that the developed device can be used as a circular polarization filter and circular polarizer at microwave frequencies.
Vegetal and Animal Food Proteins Have a Different Impact in the First Postprandial Hour of Impedance-pH Analysis in Patients with Heartburn
Authors: Martinucci Irene , Guidi Giada , Savarino Edoardo V. , Frazzoni Marzio , Tolone Salvatore , Frazzoni Leonardo , Fuccio Lorenzo , Bertani Lorenzo , Bodini Giorgia , Ceccarelli Linda , Savarino Vincenzo , Marchi Santino , de Bortoli Nicola
Published: April 2018

Background and Aims. By means of 24 h impedance-pH monitoring, we aimed to evaluate the effect of two different meals with a bromatological balanced composition: one with a prevailing component of animal proteins and the other with vegetable proteins.Patients and Methods. We enrolled 165 patients with heartburn and negative endoscopy, who underwent impedance-pH monitoring off therapy. Patients were allocated to receive a Mediterranean diet with a total caloric intake of about 1694 kcal, divided into two meals: one with a prevailing component of animal proteins and the other with vegetable proteins. We evaluated the total reflux number, acid exposure time (AET), and symptom-reflux association with impedance-pH analysis. Moreover, during the first postprandial hour (at lunch and dinner), we evaluated the total reflux number, number of acid and weakly acidic refluxes, AET, and presence of symptoms.Results. The male/female ratio was 80/85. Mean age was 51.9 ± 12.1 years. Impedance-pH analysis showed that 55/165 patients had pathological AET or a number of refluxes (nonerosive reflux disease (NERD)), 49/165 had normal AET and a number of refluxes but positive symptom-reflux association (hypersensitive esophagus (HE)), and 61/165 had normal AET and a number of refluxes with negative symptom-reflux association (functional heartburn (FH)). The overall first postprandial hour analysis showed a higher total reflux number, acid reflux number, and AET after the animal protein meal than after the vegetable protein meal. Moreover, more symptoms were reported after the animal protein meal. Similar results have been observed in the three different subcategories of patients (NERD, HE, and FH).Conclusions. Vegetable proteins are associated with a lower number of refluxes, particularly acid refluxes, and with a reduced number of symptoms during the first postprandial hour. This is a pilot study and future investigations are warranted to confirm these results.
Clustering Approaches for Pragmatic Two‐Layer IoT Architecture
Authors: Kumar J. Sathish , Zaveri Mukesh A.
Published: April 2018

Connecting all devices through Internet is now practical due to Internet of Things. IoT assures numerous applications in everyday life of common people, government bodies, business, and society as a whole. Collaboration among the devices in IoT to bring various applications in the real world is a challenging task. In this context, we introduce an application‐based two‐layer architectural framework for IoT which consists of sensing layer and IoT layer. For any real‐time application, sensing devices play an important role. Both these layers are required for accomplishing IoT‐based applications. The success of any IoT‐based application relies on efficient communication and utilization of the devices and data acquired by the devices at both layers. The grouping of these devices helps to achieve the same, which leads to formation of cluster of devices at various levels. The clustering helps not only in collaboration but also in prolonging overall network lifetime. In this paper, we propose two clustering algorithms based on heuristic and graph, respectively. The proposed clustering approaches are evaluated on IoT platform using standard parameters and compared with different approaches reported in literature.
Searching for the Minimal Seesaw Models at the LHC and Beyond
Authors: Das Arindam
Published: April 2018

The existence of the tiny neutrino mass and the flavor mixing can be naturally explained by type I Seesaw model which is probably the simplest extension of the Standard Model (SM) using Majorana type SM gauge singlet heavy Right Handed Neutrinos (RHNs). If the RHNs are around the Electroweak- (EW-) scale having sizable mixings with the SM light neutrinos, they can be produced at the high energy colliders such as Large Hadron Collider (LHC) and future 100 TeV proton-proton (pp) collider through the characteristic signatures with the same-sign dilepton introducing lepton number violations (LNV). On the other hand Seesaw models, namely, inverse Seesaw, with small LNV parameter can accommodate EW-scale pseudo-Dirac neutrinos with sizable mixings with SM light neutrinos while satisfying the neutrino oscillation data. Due to the smallness of the LNV parameter of such models, the “smoking-gun” signature of same-sign dilepton is suppressed where the RHNs in the model will be manifested at the LHC and future 100 TeV pp collider dominantly through the Lepton number conserving (LNC) trilepton final state with Missing Transverse Energy (MET). Studying various production channels of such RHNs, we give an updated upper bound on the mixing parameters of the light-heavy neutrinos at the 13 TeV LHC and future 100 TeV pp collider.