bluuebunny/crossref_metadata_2025 huggingface dataset:
Sound Radiation From Point Acoustic Sources With Shield of Large Prolate Spheroidal Baffles
Authors: Cao Xiongtao , Wang Mingsheng , Shi Lei
Published: March 2018

Sound radiation from stationary and rotating point acoustic sources with shield of rigid prolate spheroidal baffles is explored in the prolate spheroidal coordinate system. The formulae of far-field sound pressure and acoustic power are derived and acoustic power spectral density (PSD) in terms of circumferential and azimuthal wavenumber is manifested from the low frequency range to high frequency range. Acoustic wave propagation features in the spherical coordinate system as a particular case of the prolate spheroidal coordinate system are presented. Rotating sound sources cause the frequency veering phenomenon and change the patterns of PSD. Some spheroidal harmonic waves with lower and higher wavenumber for the large prolate spheroids cannot contribute to far-field sound radiation in the high frequency range when sound sources are close to the axes of the spheroids. Sound pressure directivity and acoustic power of stationary point sound sources are also analyzed with the variation of source location.
Experimental Investigation of the Flow and Heat Transfer in a Helically Corrugated Cooling Channel
Authors: Mayo Ignacio , Cernat Bogdan C. , Virgilio Marco , Pappa Alessio , Arts Tony
Published: March 2018

The detailed flow field and heat transfer were experimentally investigated in a channel with a circular cross section and equipped with a helical rib of low blockage ratio. Stereoscopic particle image velocimetry (S-PIV) was applied in order to measure the three components of the mean and turbulent velocities in the symmetry plane of the channel. Additionally, steady-state liquid crystal thermography (LCT) and infrared thermography were employed in order to study the convective heat transfer coefficient on the wall. Measurements were carried out more than six pitches downstream of the rib origin, presenting periodic velocity and heat transfer fields from this location on. The resulting velocity and heat transfer fields show similarities with those present in channels of plane walls, such as low momentum and heat transfer areas upstream and downstream of the obstacle, and high kinetic energy and heat transfer a few rib heights downstream of the obstacle. On the other hand, the shape of the rib induces a swirling motion with the same sense as the rib. The azimuthal mean velocity is negligible in the core of the pipe, but it increases considerably close to the wall.
Ultrasonic Vibration-Assisted Laser Engineered Net Shaping of Inconel 718 Parts: Microstructural and Mechanical Characterization
Authors: Ning Fuda , Hu Yingbin , Liu Zhichao , Wang Xinlin , Li Yuzhou , Cong Weilong
Published: March 2018

Laser engineered net shaping (LENS) has become a promising technology in direct manufacturing or repairing of high-performance metal parts. Investigations on LENS manufacturing of Inconel 718 (IN718) parts have been conducted for potential applications in the aircraft turbine component manufacturing or repairing. Fabrication defects, such as pores and heterogeneous microstructures, are inevitably induced in the parts, affecting part qualities and mechanical properties. Therefore, it is necessary to investigate a high-efficiency LENS process for the high-quality IN718 part fabrication. Ultrasonic vibration has been implemented into various melting material solidification processes for part performance improvements. However, there is a lack of studies on the utilization of ultrasonic vibration in LENS process for IN718 part manufacturing. In this paper, ultrasonic vibration-assisted (UV-A) LENS process is, thus, proposed to fabricate IN718 parts for the potential reduction of fabrication defects. Experimental investigations are conducted to study the effects of ultrasonic vibration on microstructures and mechanical properties of LENS-fabricated parts under two levels of laser power. The results showed that ultrasonic vibration could reduce the mean porosity to 0.1%, refine the microstructure with an average grain size of 5 μm, and fragment the detrimental Laves precipitated phase into small particles in a uniform distribution, thus enhancing yield strength, ultimate tensile strength (UTS), microhardness, and wear resistance of the fabricated IN718 parts.
Acoustic Diagnostics Applications in the Study of the Oscillation Combustion in Lean Premixed Pre-Evaporation Combustor
Authors: Zhang Zilai , Zang Shusheng , Ge Bing , Sun Peifeng
Published: March 2018

The paper presents an experimental investigation of the thermoacoustic oscillations detection in a lean premixed pre-evaporation (LPP) combustor using acoustic signals. The LPP model combustion chamber oscillation combustion test platform was designed and built; the thermal parameters signal, the acoustic signal, and the dynamic pressure signal were collected under the steady condition and the transition condition, and been analyzed comparatively. The experimental result shows that, at the same inlet air speed, the dominant frequency of the combustion chamber is proportional to the thermal load, while at the same fuel flow, the main frequency of the combustion chamber does not change with the changing of air speed. In addition, the doubling frequency of the acoustic signal is more obvious than the pressure signals, which show that the interference of the acoustic signal is less. In the transition condition, the pulse energy of the acoustic signal is obviously increased after ignition. The dominant frequency energy increases when the working condition begins to change in the stable to oscillation combustion condition. The dominant frequency energy decreases when the working condition begins to change in the oscillation to stable combustion condition. During the flameout condition, the oscillating energy begins to decay from the high frequency region. For the acoustic signal is less disturbed than the pressure signal and it can obtain the same result with the pressure signal in the oscillation condition and the transition condition, acoustic diagnostic is an auxiliary method for combustion oscillation in LPP combustor.
Coupled Dynamic Characteristics of Wind Turbine Gearbox Driven by Ring Gear Considering Gravity
Authors: Zhang Aiqiang , Wei Jing , Qin Datong , Hou Shaoshuai , Lim Teik C.
Published: March 2018

Gravity is usually neglected in the dynamic modeling and analysis of the transmission system, especially in some relatively lightweight equipment. The weight of wind turbine gearbox is up to tens of tons or even hundreds of tons, and the effects of gravity have not been explored and quantified. In order to obtain accurate vibration response predictions to understand the coupled dynamic characteristics of the wind turbine gear transmission system, a comprehensive, fully coupled, dynamic model is established by the node finite element method with gravity considered. Both time-domain and frequency-domain dynamic responses are calculated using the precise integration method with various excitations being taken into account. The results indicate that gravity has a significant impact on the vibration equilibrium position of central floating components, but the changing trends are different. Gravity does not change the composition of the excitation frequency, but will have a certain impact on the distribution ratio of the frequency components. And the high frequency vibrations are hardly affected by gravity. In addition, the load sharing coefficient is greater when gravity is taken into account, both of internal gearing and of external gearing system. When the planet gears have a certain position error in accordance with certain rules, the load sharing performance of the system will be better.
Laser-Based Fabrication of Carbon Nanotube–Silver Composites With Enhanced Fatigue Performance Onto a Flexible Substrate
Authors: Kang Zheng , Wu Benxin , Wang Ruoxing , Wu Wenzhuo
Published: March 2018

Flexible electronic devices involve electronic circuits fabricated onto a flexible (e.g., polymer) substrate, and they have many important applications. However, during their use, they often need to go through repeated deformations (such as bending). This may generate cracks in metallic components that often exist in a flexible electronic device and could obviously affect the device durability and reliability. Carbon nanotubes (CNTs) have a potential to enhance the metal fatigue properties. However, the previous work on the fabrication of CNT–metal composites onto a flexible substrate has been limited. This paper reports the research work on a novel laser-based approach to fabricate CNT–metal composites onto a flexible substrate, where mixtures containing CNTs and metal (silver) nanoparticles (NPs) are deposited onto the substrate through a dispensing device and then laser-sintered into CNT–metal composites. Under the studied conditions and for the tested samples, it has been found that overall the addition of CNTs has significantly enhanced the bending fatigue properties of the laser-sintered material without degrading the material electrical conductivity (which has actually been slightly increased). The laser-based approach has several potential advantages, such as the local, precise, and flexible production of CNT–metal composite patterns with small or little thermal effects to the flexible substrate and other surrounding regions, and without using a mask or vacuum. Future work is certainly still needed on this novel fabrication process.
A Deployable Transseptal Brace for Stabilizing Cardiac Catheters
Authors: Gaffney Leah P. , Loschak Paul M. , Howe Robert D.
Published: March 2018

A bracing device for stabilizing cardiac catheters inside the heart was developed to provide surgical-level dexterity to minimally invasive catheter-based procedures for cardiac valve disease. The brace was designed to have a folding structure, which lies flat along a catheter during navigation through vasculature and then unfolds into a rigid bracing configuration after deployment across the interatrial septum. The brace was designed to be easily deployable, provide bracing support for a transseptal catheter, and also be compliant enough to be delivered to the heart via tortuous vasculature. This aims to improve dexterity in catheter-based mitral valve repair and enable other complex surgical procedures to be done with minimally invasive instruments.
Finite Element Analysis of Origami-Based Sheet Metal Folding Process
Authors: Ali Ablat Muhammad , Qattawi Ala
Published: March 2018

Origami-based sheet metal (OSM) folding is a novel approach regarded as extension of the origami technique to sheet metal. It requires creating numerous features along the bend line, called material discontinuities (MD). Material discontinuities control the material deformation and result in reduced bending force (BF), minimal tooling, and machinery requirements. Despite the promising potential of OSM, there is little understating of the effect of the selected MD shape and geometry on the final workpiece. Specifically, this is of interest when comparing the manufacturing energy and cost allocations for OSM with a well-establish process for sheet metal such as stamping. In this work, wiping die bending of aluminum sheet with different MD shapes and geometries along the bend line is investigated using finite element analysis (FEA) and compared to traditional sheet bending in terms of stress distribution along the bending line, required bending force and springback. The FEA results are validated by comparing it to the available empirical models in terms of bending forces. This study found that OSM technique reduced the required bending force significantly, which has important significance in energy and cost reduction. The study also found each MD resulted with different bending force and localized stress. Hence, MD are ranked in terms of the required force to bend the same sheet metal type and thickness for further future investigation. Springback is decreased due to application of MD. Meanwhile, MD generated localized high stress regions along the bending line, which may affect load-bearing capability of the final part.
Effect of Dielectric Conductivity on Micro-Electrical Discharge Machining Plasma Characteristics Using Optical Emission Spectroscopy
Authors: Mujumdar Soham S. , Curreli Davide , Kapoor Shiv G.
Published: March 2018

Electrical conductivity of the dielectric liquid has been shown to play main role in discharge initiation and electrical breakdown as revealed by several modeling and experimental studies on electrical discharges in liquids. However, there has been lack of systematic efforts to evaluate how dielectric conductivity affects the micro-electrical discharge machining (micro-EDM) process, in particular. Experimental investigation has been carried out to understand the effect of dielectric conductivity on micro-EDM plasma characteristics using optical emission spectroscopy. Plasma temperature and electron density estimations have been obtained at five levels of electrical conductivity of water. It is found that while the plasma temperature shows a marginal decrease, electron density of the plasma increases with an increase in the conductivity. At increased electron density, a higher heat flux at anode can be expected resulting in increased material erosion.
Investigation of the Effect of Geometric Parameters on EWOD Actuation in Rectangular Microchannels
Authors: Pooyan Sajad , Passandideh-Fard Mohammad
Published: March 2018

Efficient actuation of liquid slugs in microfluidic circuits is a matter of interest in droplet-based microfluidic (DMF) applications. In this paper, the electrowetting on dielectric (EWOD) actuation of a liquid slug fully confined in a microchannel is studied. A set of experiments are conducted in which the mean transport velocity of a liquid slug enclosed in a microchannel of rectangular cross section and actuated by EWOD method is measured. A printed circuit board-based (PCB-based) microfluidic chip is used as the platform, and the transport velocity of the slug is measured by processing the images recorded by a high-speed camera while the slug moves in the channel. To investigate the effect of microchannel geometry on the mean transport velocity of the slugs, different channel heights and widths (ranging between 250−440μm and 1–2 mm, respectively) as well as different liquid volumes (ranging between 2.94and5.15μL) are tested and slug velocities up to 14.9 mm/s are achieved. A theoretical model is also developed to analyze the effect of involved parameters on the transport velocity. The results show that, within the range of design parameters considered in this study, for a constant slug volume and channel width, increasing the channel height enhances the velocity. Moreover, keeping the slug volume and channel height fixed, the transport velocity is increased by enlarging the channel width. An inverse proportionality between the slug length and velocity is also observed. These results are also shown to agree with the theoretical model developed.
Aerodynamics of a Convex Bump on a Ground-Effect Diffuser
Authors: Ehirim O. H. , Knowles K. , Saddington A. J. , Finnis M. V.
Published: March 2018

A ground-effect diffuser is an upward-sloping section of the underbody of a racing car that enhances aerodynamic performance by increasing the downforce, thus improving tire grip. The downforce generated by a diffuser can be increased by geometric modifications that facilitate passive flow control. Here, we modified a bluff body equipped with a 17deg diffuser ramp surface (the baseline/plane diffuser) to introduce a convex bump near the end of the ramp surface. The flow features, force, and surface pressure measurements determined in wind-tunnel experiments agreed with previous studies but the bump favorably altered the overall diffuser pressure recovery curve by increasing the flow velocity near the diffuser exit. This resulted in a static pressure drop near the diffuser exit followed by an increase to freestream static pressure, thus increasing the downforce across most of the ride heights we tested. We observed a maximum 4.9% increase in downforce when the modified diffuser was compared to the plane diffuser. The downforce increment declined as the ride height was gradually reduced to the low-downforce diffuser flow regime.
An Automated Approach for Optimizing Monopile Foundations for Offshore Wind Turbines for Serviceability and Ultimate Limit States Design
Authors: Doherty James P. , Lehane Barry M.
Published: March 2018

Pile foundation design is conventionally conducted using a process of trial and error, where the dimensions of a pile are estimated and the performance is computed and compared with design criteria. The dimensions are varied and the process is repeated in order to converge to a safe and economical design. In this paper, this time-consuming and labor intensive process is replaced with an automated approach using the example case of an offshore monopile supporting a wind turbine. The optimum length and diameter of the monopile are determined with the aim of minimizing the pile weight while satisfying both serviceability and ultimate limit state criteria. The approach handles general soil and loading conditions and includes an ability to incorporate cyclic loading.
Theoretical Analysis and Experimental Identification of a Vibration Isolator With Widely-Variable Stiffness
Authors: Hu Zhan , Wang Xing , Yao Hongxiang , Wang Guangyuan , Zheng Gangtie
Published: March 2018

This paper develops an adjustable high-static-low-dynamic (AHSLD) vibration isolator with a widely variable stiffness. By adjusting deformations of its horizontal springs, the natural frequency of the isolator can be substantially changed starting from a quasi-zero value. In this paper, the nonlinear static and dynamic analyses of the AHSLD isolator are presented. Effects of horizontal adjustments on the variation range of the stiffness and nonlinear dynamic characteristics are investigated. Good performance of the stiffness variation is validated by free-vibration tests. The wide-range variable stiffness from 0.33 N/mm to 23.2 N/mm is achieved in tests, which changes the natural frequency of the isolator from an ultra-low value of 0.72 Hz to 5.99 Hz. Besides, its nonlinear dynamic characteristics are also experimentally identified by applying the Hilbert transform. Both analytical and experimental results demonstrate the weakly hardening nonlinearity in the tested AHSLD isolator, which will not degrade its performance in practical applications.
Vibration Reduction of Mistuned Bladed Disks Via Piezoelectric-Based Resonance Frequency Detuning
Authors: Lopp Garrett K. , Kauffman Jeffrey L.
Published: March 2018

This paper extends the resonance frequency detuning (RFD) vibration reduction approach to cases of turbomachinery blade mistuning. Using a lumped parameter mistuned blade model with included piezoelectric elements, this paper presents an analytical solution of the blade vibration in response to frequency sweep excitation; direct numerical integration confirms the accuracy of this solution. A Monte Carlo statistical analysis provides insight regarding vibration reduction performance over a range of parameters of interest such as the degree of blade mistuning, linear excitation sweep rate, inherent damping ratio, and the difference between the open-circuit (OC) and short-circuit (SC) stiffness states. RFD reduces vibration across all degrees of blade mistuning as well as the entire range of sweep rates tested. Detuning also maximizes vibration reduction performance when applied to systems with low inherent damping and large electromechanical coupling.
Slip Effects on Peristaltic Flow of Magnetohydrodynamics Second Grade Fluid Through a Flexible Channel With Heat/Mass Transfer
Authors: Hina S. , Yasin Maria
Published: March 2018

In the present framework, a model is constituted to explore the peristalsis of magnetohydrodynamics (MHD) viscoelastic (second grade) fluid with wall properties. The study is beneficial in understanding blood flow dynamics through microchannels. The mechanisms of heat and mass transfer are also modeled in the existence of viscous dissipation and Soret effects. The conducting second grade fluid is permeated by a vertical magnetic field. Perturbation technique is opted to present series solutions by assuming that the wavelength of the sinusoidal wave is small in comparison to the half-width of the channel. The solution profiles are computed and elucidated for a certain range of embedded parameters. Moreover, plots of heat transfer coefficient against the axial coordinate are also portrayed and deliberated. The main outcome of the current research is that both viscoelasticity and slip effect considerably alter the flow fields. Moreover, an increasing trend in solute concentration is anticipated for increasing the Soret effect strength.
Damping Design of Flexible Structures With Graded Materials Under Harmonic Loading
Authors: Alfouneh Mahmoud , Tong Liyong
Published: March 2018

This article presents a novel moving isosurface threshold (MIST) method for designing flexible structures using graded materials with multivolume fractions and constraints and viscous or hysteretic damping under harmonic loadings. By employing a unit dynamic load with the same frequency of an applied load, the displacement amplitude at chosen degrees-of-freedom (DOFs) can be expressed in an integral form in terms of mutual modal strain and kinetic energy densities over the entire design domain. Such integrals enable the introduction of novel physical response functions for solving a range of topology optimization problems, including single and multiple objectives with single and multiple volume fractions and/or constraints, e.g., single-input and single-output (SISO) and multi-input and multi-output (MIMO). Numerical examples are presented to validate the efficiency and capability of the present extended MIST method. Experiments are also conducted on rectangular plates with and without damping layer, fully and optimally covered, to demonstrate the benefits of the optimal damping layer design.
Acquisition Cost-Torque Capacity-Reliability Modeling for Spur Gears
Authors: Lotfalian Reza , Martins Sudarshan , Radziszewski Peter , Boulet Benoit
Published: March 2018

This paper studies the influence of macrogeometry and material type of spur gears on their torque capacity, reliability, and acquisition cost. The developed model indicates how costly it is to enhance the torque capacity or the reliability of gears. The results are in agreement with the catalog prices of a manufacturer in a wide size range and different modules. The model provides a simple cost estimation tool for multi-objective gear design and optimization.
Insight From Recent Experimental and Empirical-Model Studies on Flow-Regime Characteristics in Debris Bed Formation Behavior
Authors: Cheng Songbai , Zhang Ting , Cui Jinjiang , Gong Pengfeng , Qian Yujia
Published: March 2018

Studies on debris bed formation behavior are important for improved evaluation of core relocation and debris bed coolability that might be encountered in a core disruptive accident (CDA) of sodium-cooled fast reactors (SFR). Motivated to clarify the flow-regime characteristics underlying this behavior, both experimental investigations and empirical-model development are being performed at the Sun Yat-sen University in China. As for the experimental study, several series of simulated experiments are being conducted by discharging various solid particles into water pools. To obtain a comprehensive understanding, a variety of experimental parameters, including particle size (0.000125– 0.008 m), particle density (glass, aluminum, alumina, zirconia, steel, copper, and lead), particle shape (spherical and nonspherical), and water depth (0–0.8 m) along with the particle release pipe diameter (0.01–0.04 m) were varied. It is found that due to the different interaction mechanisms between solid particles and water pool, four kinds of flow regimes, termed, respectively, as the particle-suspension regime, the pool-convection dominant regime, the transitional regime, and the particle-inertia dominant regime, were identifiable. As for the empirical-model development, aside from a base model which is restricted to predictions of spherical particles, in this paper considerations on how to cover more realistic conditions (esp. debris of nonspherical shapes) are also discussed. It is shown that by coupling the base model with an extension scheme, respectable agreement between experiments and model predictions for regime transition can be achieved for both spherical and nonspherical particles given our current range of conditions.
Microwave-Assisted Pyrolysis of Biomass for Bio-Oil Production: A Review of the Operation Parameters
Authors: Zhang Yaning , Zhao Wenke , Li Bingxi , Xie Gongnan
Published: March 2018

As compared with the conventional electrical heating pyrolysis, microwave-assisted pyrolysis (MAP) is more rapid and efficient due to its unique heating mechanisms. However, bio-oil production from MAP of biomass is strongly dependent on the operation parameters. Based on the recent researches, this study reviews the effects of the main operation parameters including microwave power, pyrolysis temperature, and pyrolysis time on the bio-oil yield obtained from MAP of biomass. The results show that microwave power, pyrolysis temperature, and pyrolysis time usually increase the bio-oil yield initially and decrease the bio-oil yield finally. The reported optimal microwave powers, pyrolysis temperatures, and pyrolysis times were mainly in the ranges of 300–1500 W, 400–800 °C, and 6–25 min, respectively. The mechanisms for bio-oil produced from MAP of biomass as affected by the main operation parameters were also analyzed.
Simple plasma assisted atomic layer deposition technique for high substitutional nitrogen doping of TiO2
Authors: Alshehri Abdullah H. , Nelson-Fitzpatrick Nathan , Ibrahim Khaled H. , Mistry Kissan , Yavuz Mustafa , Musselman Kevin P.
Published: March 2018

In this work, a plasma assisted atomic layer deposition system was used to deposit nitrogen-doped titanium dioxide. A simple approach was developed that requires only a nitrogen plasma and short plasma exposure times to effectively dope TiO2. A range of nitrogen concentrations were achieved by varying the flow rate and exposure times of nitrogen and oxygen plasmas. A nitrogen content as high as 23 ± 0.5 at. % was observed when only the nitrogen plasma was used. It was also possible to vary the type of nitrogen doping from almost entirely interstitial to purely substitutional, as measured by x-ray photoelectron spectroscopy. Ultraviolet-visible spectroscopy measurements showed a shifting in the absorption edge from 350 to 520 nm with doping, indicating bandgap narrowing from 3.1 to 1.9 eV.
Comment on “
Aggregatibacter actinomycetemcomitans
–induced hypercitrullination links periodontal infection to autoimmunity in rheumatoid arthritis”
Authors: Volkov Mikhail , Dekkers Jacqueline , Loos Bruno G. , Bizzarro Sergio , Huizinga Thomas W. J. , Praetorius Helle A. , Toes René E. M. , van der Woude Diane
Published: March 2018

The link between rheumatoid arthritis and exposure to a bacterial toxin was not found in a population of rheumatoid arthritis patients from Netherlands.
Draft Genome Sequence of Bacillus velezensis Lzh-a42, a Plant Growth-Promoting Rhizobacterium Isolated from Tomato Rhizosphere
Authors: Li Zhenghua , Chen Mei , Ran Kun , Wang Jihua , Zeng Qiangcheng , Song Feng
Published: March 2018

The plant growth-promoting rhizobacterium
Bacillus velezensis
strain Lzh-a42, which has antimicrobial activity, was isolated from tomato rhizosphere. Here, we report its genome sequence, which includes several predicted functional genes related to secondary metabolite biosynthesis, antimicrobial activity, and biofilm synthesis.
Complete Genome Sequence of the Live Attenuated Vaccine Strain Brucella melitensis Rev.1
Authors: Salmon-Divon Mali , Banai Menachem , Bardenstein Svetlana , Blum Shlomo E. , Kornspan David
Published: March 2018

Live attenuated vaccines are essential elements in control programs for the prevention of brucellosis. Here, we report the whole-genome sequence of the original Elberg
Brucella melitensis
Rev.1 vaccine strain, passage 101 (1970). Commercial lines of the original strain have been successfully used in small ruminants worldwide.
Draft Genome Sequence of Bacillus velezensis B6, a Rhizobacterium That Can Control Plant Diseases
Authors: Gao Yu-han , Guo Rong-jun , Li Shi-dong
Published: March 2018

The draft genome of
Bacillus velezensis
strain B6, a rhizobacterium with good biocontrol performance isolated from soil in China, was sequenced. The assembly comprises 32 scaffolds with a total size of 3.88 Mb. Gene clusters coding either ribosomally encoded bacteriocins or nonribosomally encoded antimicrobial polyketides and lipopeptides in the genome may contribute to plant disease control.
Draft Genome Sequence of Carbapenem-Resistant Pseudomonas fluorescens Strain BWKM6, Isolated from Feces of Mareca penelope
Authors: Kenzaka Takehiko , Tani Katsuji
Published: March 2018

Migratory birds are potential vehicles of antibiotic-resistant bacteria. Here, we isolated the multidrug-resistant
Pseudomonas fluorescens
strain BWKM6 from the feces of
Mareca penelope
. The strain’s draft genome sequence indicates that it harbors a metallo-beta-lactamase, a class C beta-lactamase, and several multidrug efflux pumps.
Women, ‘madness’ and exercise
Authors: Hardes Jennifer Jane
Published: March 2018

The positive relationship between exercise and mental health is often taken for granted in today’s society, despite the lack of academic literature evidencing this symbiosis. Gender is considered a significant determinant in a number of mental health diagnoses. Indeed, women are considered twice as likely as men to experience the most pervasive mental health condition, depression. Exercise for women’s mental health is promoted through various macrolevel charity, as well as microlevel, campaigns that influence government healthcare policy and National Health Service guidelines. Indeed, ‘exercise prescriptions’ in the treatment of depression is not uncommon. Yet, this link between exercise as a treatment for women’s mental health has not always been so pervasive. In fact, an examination of asylum reports and medical journals from the late 19th century highlights a significant shift in attitude towards the role of exercise in the treatment of women’s emotional states and mental health. This paper specifically examines how this treatment of women’s mental health through exercise has moved from what might be regarded as a focus on exercise as a ‘cause’ of women’s mental ailments to exercise promoted as a ‘cure’. Unpacking the changing medical attitudes towards exercise for women in line with larger sociopolitical and historic contexts reveals that while this shift towards exercise promotion might prima facie appear as a less essentialist view of women and their mental and physical states, it inevitably remains tied to larger policy and governance agendas. New modes of exercise ‘treatment’ for women’s mental health are not politically neutral and, thus, what appear to emerge as forms of liberation are, in actuality, subtler forms of regulation.
Republished: Flanking the fenestration: circumferential limb-to-limb stent-assisted coiling of a basilar artery fenestration aneurysm
Authors: Morrison Joseph , Alexander Matthew David , Dowd Christopher F , Cooke Daniel L
Published: March 2018

A man aged 61 years with a history of a ruptured basilar fenestration aneurysm underwent unassisted coiling in 1997 and repeat intervention for a recurrence at the aneurysm mouth in 2011. At repeat intervention, the decision was made to intentionally leave some filling at the base to preserve the parent vessels. Stent-assisted coil embolization, although technically feasible, was not pursued given the relative risks of the procedure. In 2017, the patient returned for repeat surveillance and further coil compaction was found at the aneurysm base. With the advent of more compliant woven stents deliverable through 0.017 microcatheters, stent-assisted coiling was possible. This case demonstrates hereto unseen agility afforded by novel low-profile stents allowing a circumferential approach to a basilar artery fenestration aneurysm and resultant limb-to-limb stent-assisted coiling. Techniques described here may be extended to more common anatomic variants that require stent-assisted coiling.
Alternaria sensitisation at age 6 years is associated with subsequent airway hyper-responsiveness in non-asthmatics
Authors: Hiranrattana Anunya , Stern Debra A , Guerra Stefano , Halonen Marilyn , Wright Anne L , Daines Michael , Martinez Fernando D , Morgan Wayne J
Published: March 2018

In the non-selected birth cohort Tucson Children’s Respiratory Study, early sensitisation to Alternaria was associated with increased airway hyper-responsiveness (AHR) into adult life among non-asthmatics. The increase in AHR was of a similar magnitude to that seen for Alternaria sensitised asthmatics and was primarily evident among those who were overweight or obese. In contrast, there was no significant association between early sensitisation to aeroallergens other than Alternaria and AHR among non-asthmatics. Why this group of Alternaria sensitised individuals without asthma demonstrated increased AHR of a magnitude similar to asthmatics is unknown and requires further investigation.
Using velocity loss for monitoring resistance training effort in a real-world setting
Authors: Gentil Paulo , Marques Vítor A. , Neto Josaphat P.P. , Santos Anna C.G. , Steele James , Fisher James , Paoli Antonio , Bottaro Martim
Published: March 2018

The purpose of the present study was to evaluate the changes in movement velocity during resistance training with different loads while the trainees attempted to move the load at a predetermined repetition duration. Twenty-one resistance-trained men (age: 25.7 ± 5 years; height: 177.0 ± 7.2 cm; mass: 85.4 ± 13.56 kg) volunteered to participate in the study. Participants performed 2 test sessions. The first to determine 1-repetition maximum (1RM) load, and the second to evaluate velocity loss during a set to failure performed at 75% and 50% of 1RM using a 2-s concentric and 2-s eccentric repetition duration, controlled by a mobile app metronome. When using 75% 1RM there was a significant loss of movement velocity between the antepenultimate and the penultimate repetition (5.33%, p < 0.05), as well as during the penultimate and the last (22.11%, p < 0.05). At 50% of 1RM the participants performed the set until momentary failure without significant velocity loss. Monitoring velocity loss during high-load resistance training through simple methods can be an important tool for standardize the intensity of effort employed during submaximal training. This can be useful in clinical conditions where maximum exertions are contraindicated or when specific logistics are lacking.
The Geon 14 arc-related mafic rocks from the central Grenville Province
Authors: Maity Barun , Indares Aphrodite
Published: March 2018

The late Paleoproterozoic to Mesoproterozoic (ca. 1.7–1.2 Ga) evolution of the active southeastern margin of Laurentia terminated with the Grenvillian continental collision and the development of a large, hot, long-duration orogen at ca. 1.09–0.98 Ga. As a result, much of the hinterland of the Grenville Province consists of Paleoproterozoic and Mesoproterozoic rocks, mostly preserved as an imbricate stack of high-grade gneisses, that represent a potential repository of active-margin processes. This study presents geochronologic, geochemical, and isotopic analyses of two granulite-facies suites of ca. 1.45–1.40 Ga mafic tholeiites from the Canyon domain (Manicouagan area, central Grenville Province). One suite consists of 1439 +76/–68 Ma high-FeTi mafic sills with εNd values of –0.4 (TDM 2.57–2.72 Ga), indicate derivation from variably depleted to enriched MORB-type mantle sources, probably in an extensional back-arc setting, before intrusion in a ca. 1.5 Ga supracrustal metasedimentary sequence. The other, previously dated, 1410 ± 16 Ma Mafic to intermediate unit exhibits εNd values of 0.0 to +0.9 (TDM 2.02–2.25 Ga), and variably enriched MORB to arc geochemical signatures, for which formation in a transitional back-arc to arc setting is suggested. Integrated with published information, the new data support a model of a long-lived continental-margin arc and intermittent back-arc development on southeast Laurentia during the mid-Mesoproterozoic (ca. 1.5–1.4 Ga), in which repeated short periods of extension and crustal thinning in the back-arc or intra-arc regions were followed by compression and crustal thickening.
Experimental Validation of Impedance Source Network Based Active Power Filter for Interconnection of PV System into Grid
Authors: Jamuna P. , Ramesh S.
Published: March 2018

This paper proposes a Solar Photovoltaic (SPV) interfaced Impedance Source Inverter (ZSI) based shunt Active Power Filter (APF) for compensation of power quality events such as current harmonics, voltage interruption and reactive power burden. The instantaneous reactive power theories with Fuzzy Logic Controller (FLC) based DC link voltage regulator is used to estimate the reference current signal and control the operation of the SPV interfaced shunt APF. Maximum Power Point Tracking (MPPT) algorithm is also employed to obtain the optimum maximum power point. The response of the SPV interfaced ZSI-shunt APF for mitigation of current harmonic distortions and reactive power compensation are investigated and compared with SPV interfaced Voltage Source Inverter (VSI) based shunt APF. The proposed SPV interfaced shunt APF employed with the FLC-based instantaneous reactive power theory control algorithm offers long lasting compensation against current-based distortions and reactive power requirements. The performance of the SPV interfaced ZSI based shunt APF has been verified by the simulation and experimental study. These results confirm the practicability of the proposed system in various load conditions with effective harmonic mitigation capability.
Optimized Parity-Based Error Detection and Correction Methods for Residue Number System
Authors: Armand Adib , Timarchi Somayeh , Mahdavi Hossein
Published: March 2018

Residue Number System (RNS) has been extensively used in high-speed applications. It inherits the advantages of parallelism and modularity, which lead to fault tolerance property. Since carry propagation is limited to each module in RNS, errors do not propagate inter-moduli. Indeed, due to the restriction in carry propagation and fault tolerance property, RNS can be promisingly fast and reliable that makes it a favorable encoding for the digital systems which are highly prone to noise like communication channels. By adding some extra moduli, the so-called redundant RNS (RRNS) is gained. Although several methods around RRNS have already been proposed in the literature, the structures without need for extra moduli have not been introduced yet. This paper addresses three Error Detection and Correction (EDC) schemes for RNS based on parity structures. Using these techniques, the low power fault-tolerant RNS methods with low complexity are presented. Synthesis results using 180[Formula: see text]nm CMOS standard cell library show that the proposed architectures for the three-moduli set [Formula: see text] are in average 17%, 52% and 44% more efficient than the conventional RRNS in terms of delay, power consumption, and area overhead, respectively, without losing the EDC capability.
Maximally Flat and Least-Square Co-Design of Variable Fractional Delay Filters for Wideband Software-Defined Radio
Authors: Li Haolin , Van Kerrebrouck Joris , Bauwelinck Johan , Demeester Piet , Torfs Guy
Published: March 2018

This paper describes improvements in a Farrow-structured variable fractional delay (FD) Lagrange filter for all-pass FD interpolation. The main idea is to integrate the truncated sinc into the Farrow structure of a Lagrange filter, in order that a superior FD approximation in the least-square sense can be achieved. Its primary advantages are the lower level of mean-square-error (MSE) over the whole FD range and the reduced implementation cost. Extra design parameters are introduced for making the trade-off between MSE and maximal flatness under different design requirements. Design examples are included, illustrating an MSE reduction of [Formula: see text] compared to a classical Farrow-structured Lagrange interpolator while the implementation cost is reduced. This improved variable FD interpolation system is suitable for many applications, such as sample rate conversion, digital beamforming and timing synchronization in wideband software-defined radio (SDR) communications.
THE HADAMARD FRACTIONAL CALCULUS OF A FRACTAL FUNCTION
Authors: WU YIPENG , YAO KUI , ZHANG XIA
Published: March 2018

This paper investigates the Hadamard fractional calculus of a fractal function. It is proved that there exists some linear relationship between the order of Hadamard fractional calculus and the fractal dimension of the Weierstrass function including Box dimension, [Formula: see text]-dimension and Packing dimension. Furthermore, numerical result is given to show the linear relationship.
ASYMPTOTIC FORMULA ON AVERAGE PATH LENGTH OF A SPECIAL NETWORK BASED ON SIERPINSKI CARPET
Authors: XUE YUMEI , ZHOU DONGXUE
Published: March 2018

In this paper, we construct a special network based on the construction of the Sierpinski carpet. Using the self-similarity and renewal theorem, we obtain the asymptotic formula for the average path length of our evolving network.
NONLINEAR CHARACTERISTICS OF ACOUSTIC EMISSION DURING THE HEATING PROCESS OF COAL AND ROCK
Authors: ZHANG ZHIBO , WANG ENYUAN , ZHAO ENLAI , YANG SHUAI
Published: March 2018

In this paper, acoustic emission (AE) signal of coal and rock samples during the heating process are measured. The results show that AE energy of coal samples is higher than that of rock samples. Based on the multifractal theory, the multifractal characteristics of AE signal are researched. The multifractal spectrum width ([Formula: see text]) of coal samples is wider than that of rock samples, which means AE signal of coal samples is more complex than AE signal of rock samples during the heating process. Multifractal parameter ([Formula: see text]) is more than zero, illustrating that small AE signal is dominate. The time-varying multifractal characteristics are analyzed, and the change trend of multifractal spectrum width ([Formula: see text]) of coal and rock samples is consistent. At the stage of 40–50[Formula: see text]C, multifractal spectrum width ([Formula: see text]) gets the maximum value, whereas multifractal spectrum width ([Formula: see text]) gets the minimum value at the stage of 80–100[Formula: see text]C. For coal samples, multifractal parameter ([Formula: see text] is more than zero except at the stage of 40–50[Formula: see text]C. However, multifractal parameter ([Formula: see text] of rock samples is always more than zero during the entire heating process. By [Formula: see text] analytical method, Hurst exponent of AE signal is calculated. The results show that Hurst exponent of coal and rock samples are more than 0.5, which indicate that AE signal presents persistence, and there is a positive correction between AE signal and temperature. In different temperature levels, Hurst exponent curve presents an increase trend after the initial decrease.
Plant Vacuoles
Authors: Shimada Tomoo , Takagi Junpei , Ichino Takuji , Shirakawa Makoto , Hara-Nishimura Ikuko
Published: March 2018

Plant vacuoles are multifunctional organelles. On the one hand, most vegetative tissues develop lytic vacuoles that have a role in degradation. On the other hand, seed cells have two types of storage vacuoles: protein storage vacuoles (PSVs) in endosperm and embryonic cells and metabolite storage vacuoles in seed coats. Vacuolar proteins and metabolites are synthesized on the endoplasmic reticulum and then transported to the vacuoles via Golgi-dependent and Golgi-independent pathways. Proprotein precursors delivered to the vacuoles are converted into their respective mature forms by vacuolar processing enzyme, which also regulates various kinds of programmed cell death in plants. We summarize two types of vacuolar membrane dynamics that occur during defense responses: vacuolar membrane collapse to attack viral pathogens and fusion of vacuolar and plasma membranes to attack bacterial pathogens. We also describe the chemical defense against herbivores brought about by the presence of PSVs in the idioblast myrosin cell.
Dynamic Neutron Scattering by Biological Systems
Authors: Smith Jeremy C. , Tan Pan , Petridis Loukas , Hong Liang
Published: March 2018

Dynamic neutron scattering directly probes motions in biological systems on femtosecond to microsecond timescales. When combined with molecular dynamics simulation and normal mode analysis, detailed descriptions of the forms and frequencies of motions can be derived. We examine vibrations in proteins, the temperature dependence of protein motions, and concepts describing the rich variety of motions detectable using neutrons in biological systems at physiological temperatures. New techniques for deriving information on collective motions using coherent scattering are also reviewed.
Loss of Parkin impairs mitochondrial function and leads to muscle atrophy
Authors: Peker Nesibe , Donipadi Vinay , Sharma Mridula , McFarlane Craig , Kambadur Ravi
Published: March 2018

Parkinson’s disease is a neurodegenerative disease characterized by tremors, muscle stiffness, and muscle weakness. Molecular genetic analysis has confirmed that mutations in PARKIN and PINK1 genes, which play major roles in mitochondrial quality control and mitophagy, are frequently associated with Parkinson’s disease. PARKIN is an E3 ubiquitin ligase that translocates to mitochondria during loss of mitochondrial membrane potential to increase mitophagy. Although muscle dysfunction is noted in Parkinson’s disease, little is known about the involvement of PARKIN in the muscle phenotype of Parkinson’s disease. In this study, we report that the mitochondrial uncoupler CCCP promotes PINK1/PARKIN-mediated mitophagy in myogenic C2C12 cells. As a result of this excess mitophagy, we show that CCCP treatment of myotubes leads to the development of myotube atrophy in vitro. Surprisingly, we also found that siRNA-mediated knockdown of Parkin results in impaired mitochondrial turnover. In addition, knockdown of Parkin led to myotubular atrophy in vitro. Consistent with these in vitro results, Parkin knockout muscles showed impaired mitochondrial function and smaller myofiber area, suggesting that Parkin function is required for post-natal skeletal muscle growth and development.