bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Two-Bit Reflectarray Element Using Cut-Ring Patch Coupled to Delay Lines
Authors: Nguyen Binh Duong , Tran Van-Su , Mai Linh , Dinh-Hoang Phuc 
Published: May 2016

In this paper, a two-bit element for reflectarray applications is presented. The proposed element is based on the cut-ring patch coupled to delay lines through an annular slot. The four states of the reflection phase with a step of 90◦ are achieved with two switches. This reported work is the first step towards the 2-bit active reflectarray element. Prototypes of the element have been fabricated and characterized in X-band using waveguide simulator. Measured results show good characteristics with low magnitude losses and the bandwidth of 1.7-bit resolution is over 5%.
A study on the application of the operating modal analysis method in self-propelled gun development
Authors: Liu Pengke , Shao Xiaojun , Zhou Faming , Chao Hongxiao 
Published: May 2016

The basic theory and main features of operating modal analysis method have been elaborated, and then by using this method, the parameters of low-order natural characteristics of some wheeled and tracked self-propelled guns have been obtained. By two examples, the application of the operating modal analysis method for the development of self-propelled gun has been introduced. According to the result of operating modal analysis, for some wheeled self-propelled gun, “beat vibration” between the first-order natural characteristics and firing frequency of the gun has been identified, and further research indicates that the primary cause of the “beat vibration” is that the stiffness of the cradle is too weak which enlarges the vibratory response of the muzzle. With the reinforcement of the cradle, the testing result of firing indicates that the vibratory response of the muzzle is reduced obviously, and that the firing dispersion is much better than before. In order to certificate the accuracy of its dynamic model, for some tracked self-propelled guns, the natural characteristics of the whole gun through a comparison of the operating modal analysis and finite element calculation have been specified, and then according to the results of operating modal analysis, the dynamic model of the gun has been meliorated, and the natural characteristics of the gun by the finite element calculation are consistent with those by the operating modal analysis. This indicates that the model of the gun is correct with the vibratory response of the whole gun under seven running fire simulated, and that the error of vibratory response of the muzzle between firing testing and analog simulation does not exceed 15 %.
Investigation of pressure pulsations in centrifugal pump system
Authors: Barzdaitis Vytautas , Mažeika Pranas , Vasylius Marius , Kartašovas Valentinas , Tadžijevas Artūras 
Published: May 2016

This article presents the results obtained on vibration measurements of the centrifugal pumps together with the measurements of pressure pulsations, generated in the pipeline system. The main task of the current investigation, developed based on previously conducted substantiated experimental investigations, is to identify the main source of pressure pulsations in the pipeline system. More than 9 different operating modes were set for high capacity (up to 1000 m3/h) centrifugal pumps during the vibration and pressure pulsation measurement processes. Throughout the measurements, the high capacity pumps, connected in series or parallel, were transferring fluids to a pipeline, in a length of more than 350 meters. Having conducted the experimental investigation, the main source of pressure pulsations, generated in the pipeline system, was identified.
Analysis of the influence of braking control laws on gear walk
Authors: Yin Qiaozhi , Nie Hong , Zhang Ming , Wang Yongquan , Deng Jian 
Published: May 2016

The problem of gear walk on landing gear becomes increasingly serious. A rigid-flexible coupling dynamic half-axle main landing gear model, verified to be in accordance with the test data and the original deceleration control system, are built to study the gear walk problems. The co-simulation method is adopted. According to the severe gear walk phenomenon under the deceleration braking system, two modified braking control laws-only the reference speed-speed difference (with PBM) control and the one combining the PBM with the fuzzy control are designed for this type of airplane to weaken the gear walk. The simulating results show that the modified braking control law weakens the gear walk considerably. The braking frequency increases by about 17 %. The average wheel axle gear walk average amplitude decreases by 73 % and the longitudinal acceleration drops by about 91 %. The braking frequency decreases by 50 % so that the vibration frequency of the gear walk decreases by about 59 %. The combined braking control law is verified that is of great stability, adaptability and robustness under variable external conditions.
A combined computational and experimental study on vibration stress relief for large welded DH36 steel tube
Authors: Li Shuqi , Fang Hongyuan , Liu Xuesong , Wang Wei , Wang Qiang , Cui Wei 
Published: May 2016

Vibration stress relief (VSR) is an effective and economic method for reducing residual stress in various welding components. Compared with other methods, it costs much less time and energy. In this study, finite element method (FEM) was used to assist VSR treatment of large DH36 steel welded tube by determining the 1st order vibration mode of the tube and the natural frequency of the tube in a hypothetic zero-stress state. According to the computational results, proper vibration exciting assembling and excitation strategy was selected. An effectiveness index, η, for fast and quantitative estimation of the residual stress decrease rate was proposed. η is determined by 1st order natural frequencies of the tube in three states, i.e. as-welded, VSR treated and a hypothetic zero-stress state. η in this study was 49.8 %, meeting well with the experimentally measured residual stress decrease rate, ~50 %. Thus, the validity of the effectiveness index was verified. This study provides a novel method for analysis of VSR effectiveness. In comparison, maximum residual stress was reduced by 20-57 % when traditional local post weld heat treatment (PWHT) was used. This indicates that VSR is a good stress relief method for DH36 welded structures.
The ride comfort and energy-regenerative characteristics analysis of hydraulic-electricity energy regenerative suspension
Authors: Gong Bian , Guo Xuexun , Hu Sanbao , Fang Zhigang 
Published: May 2016

For optimization of performances of a hydraulic-electricity energy regenerative suspension (HERS) unit, the tradeoff point was determined based on study of ride comfort and energy-regenerative characteristics of a HERS unit in this study. A HERS unit as a new energy reclaiming suspension device is equipped with an energy-harvesting hydraulic electromagnetic shock absorber (HESA). The HESA together with a quarter car was modeled based on theoretical analysis and experiments, in which the root mean square (RMS) values of the sprung mass vibration acceleration and the recovered power are regarded as the optimization objectives under different road excitation conditions such as the constraints (natural frequency, dynamic displacement, and dynamic load of wheels). The HERS unit was optimized after the relationship between the ride comfort and the energy regeneration was obtained. In comparison with the traditional suspension, the HERS unit may be utilized to improve the ride comfort and meet the vehicle-driving requirements. Moreover, the total input power may be saved by 34-100 W on average while the vibration acceleration is among 0.65-1.06 m/s2. Furthermore, it is verified that the HERS damping force control is the feasible under various load currents.
Multistage throttling characteristics of reverse direction impact of pilot operated check valve
Authors: Liu Lei , Zhao Jiyun 
Published: May 2016

The aim of this study was to improve the reverse impact characteristics of large-flow pilot operated check valves, meanwhile reduce oscillation, cavitation and unloading time. Three different main poppets were selected, and the impact pressure and flow were set as 30 MPa and 1000 L/min, respectively. The cavitation phenomenon was explored based on the analysis of gas-liquid two-phase flow by Fluent software, and then experimental verification was performed. Meanwhile, the dynamic characteristics of pilot operated check valves were analyzed by the impact test system. The simulation results showed that the fluid pressure clearly decreased while flowing through the poppet area. The sudden decrease of flow area at the orifice port of the poppet resulted in an increase in flow-velocity, because the cavitation area appears on the side of the main poppet. A stepped throttling structure could effectively reduce the cavitation area, preventing the generation of cavitation. The experimental results showed that the pressure oscillation of a stepped main poppet significantly reduced during the process of unloading, at 28.41 MPa; with a flow gradient of 4.86×105 L/min2; unloading time significantly reduced, for 711 ms; indicating it opened more rapidly and dynamic characteristics was superior. It can be concluded that the stepped throttling structure could effectively reduce the pressure oscillation of a pilot operated check valve during the process of unloading, improve response speed, enhance the impact properties, and reduce cavitation. This verified the correctness of the simulation and the rationality of the cavitation index.
Total Hip Arthroplasty for the Paralytic and Non-paralytic Side in Patient with Residual Poliomyelitis
Authors: Sonohata Motoki , Kitajima Masaru , Kawano Shunsuke , Mawatari Masaaki 
Published: May 2016

Background:
Total hip arthroplasty (THA) for poliomyelitis is a problematic procedure due to difficulty in positioning the cup of the prosthesis in the true acetabulum and the risk of dislocation after THA due to the low muscle tone.

Methods:
We herein present a case of bilateral hip pain with a history of poliomyelitis. Radiograph showed bilateral hip osteoarthritis caused by hip dysplasia due to residual poliomyelitis in right hip joint or developing dysplasia of the hip joint in left hip joint. THA was performed to bilateral hip joints.

Results:
Six years after bilateral THA, bilateral hip pain significantly improved. Additionally, the muscle strength on the paralyzed right side partially improved. However, the muscle strength on the non-paralyzed left side did not significantly improve. No complications related to the surgery were observed.

Conclusion:
Promising early results were obtained for THA in our patient with residual poliomyelitis. However, surgeons should pay attention to the potential development of complications concerning THA that may arise due to the residual poliomyelitis.
Dynamic smile evaluation in different skeletal patterns
Authors: Siddiqui Noshi , Tandon Pradeep , Singh Alka , Haryani Jitesh 
Published: May 2016

ABSTRACT

Objective:
To evaluate dynamic smile in different skeletal patterns and to correlate vertical smile parameters with the underlying causative factors.

Materials and Methods:
A total of 150 participants ranging in age from 16–25 years were selected and divided into one of three groups—horizontal, average, and vertical skeletal pattern—using the following three cephalometric parameters: SN-MP, FMA, and Jarabak ratio. Videographic records of smile were obtained, and measurements were recorded and analyzed at rest, including upper lip length, and during smile, including maxillary incisal display, interlabial gap, intercommisural width, change in upper lip length, and smile arc. Differences among the three groups were subjected to two-way analysis of variance and post hoc and chi-square tests for smile arc. Correlations between vertical smile variables and vertical skeletal (N-ANS, N-Me) and dental cephalometric measurements (U1 to palatal plane) were also investigated.

Results:
Vertical parameters were significantly increased in the vertical pattern when compared with the horizontal pattern, ie, upper lip length (P &lt; .01), maxillary incisal display (P &lt; .001), interlabial gap (P &lt; .001), and change in upper lip length (P &lt; .001), whereas intercommisural width was significantly decreased in vertical pattern when compared with the horizontal pattern (P &lt; .001). Flat smile arc was seen more frequently in the horizontal pattern. Positive correlations were found between the N-Me, U1-PP, and change in upper lip length with vertical smile parameters.

Conclusions:
Different skeletal patterns exhibit their characteristic smile features. Upper lip length is not responsible for increased incisal display during smile. Increased incisal display during smile is more closely associated with upper lip elevation than vertical skeletal and dental factors.
Microleakage under ceramic flash-free orthodontic brackets after thermal cycling
Authors: Kim Julia , Kanavakis Georgios , Finkelman Matthew D. , Lee Moonyoung 
Published: May 2016

ABSTRACT
Objective: To compare microleakage under 3M Unitek's APC Flash-Free Adhesive Coated System bracket and the APC PLUS Adhesive Coated System bracket after thermal cycling.
Materials and Methods: Forty freshly extracted human maxillary premolars were randomly divided into two groups and bonded with either a Flash-Free bracket or a PLUS bracket. After bonding, the samples were incubated in a water bath at 37°C for 24 hours and thermocycled for 5000 cycles between 5°C and 50°C. All teeth were immersed in a 2% methylene blue solution for 24 hours, embedded in acrylic and sectioned in a buccolingual direction at approximately the center of the bracket. Microleakage was observed at the enamel-adhesive interface from the occlusal and gingival margins of the bracket base. Statistical analysis was conducted using the Mann-Whitney U-test.
Results: The median microleakage was higher in the Flash-Free group, but the difference between the two groups was not statistically significant (P &gt; .05).
Conclusion: In a laboratory setting, there is no significant difference between the extent of microleakage under the APC Flash-Free Adhesive Coated System bracket and the APC PLUS Adhesive Coated System bracket after thermal cycling.
Development and characterization of 15 microsatellite markers for Cephalotaxus fortunei (Cephalotaxaceae)
Authors: Wang Chunbo , Guo Zhiyou , Huang Xilian , Huang Lu 
Published: May 2016

Premise of the study:To survey population variation and the adaptive evolution of Cephalotaxus fortunei (Cephalotaxaceae), an endemic and endangered conifer in China, microsatellite markers were developed and characterized for this species.Methods and Results:Based on the Fast Isolation by AFLP of Sequences COntaining repeats (FIASCO) protocol, 15 microsatellite markers were developed for C. fortunei, 13 of which were polymorphic within a sample of 75 individuals representing five natural populations. The number of alleles per locus ranged from one to seven. The expected and observed heterozygosities were 0.108–0.738 and 0.000–1.000, respectively. Ten polymorphic loci were also successfully amplified in C. oliveri.Conclusions:These polymorphic loci provide a valuable tool for population genetic analysis of C. fortunei, which will contribute to its management and conservation.
Microsatellite primers for a species of South African everlasting daisy (Helichrysum odoratissimum; Gnaphalieae, Asteraceae)
Authors: Glennon Kelsey L. , Cron Glynis V. 
Published: May 2016

Premise of the study:Microsatellites were developed for the widespread Helichrysum odoratissimum (Asteraceae) to estimate gene flow across diploid populations and to test if gene flow occurs among other closely related lineages within this genus.Methods and Results:Ten primer pairs were developed and tested using populations across South Africa; however, only seven primer pairs were polymorphic for the target species. The seven polymorphic primers amplified di‐ and trinucleotide repeats with up to 16 alleles per locus among 125 diploid individuals used for analyses.Conclusions:These markers can be used to estimate gene flow among populations of known ploidy level of H. odoratissimum to test evolutionary hypotheses. Furthermore, these markers amplify successfully in other Helichrysum species, including the other three taxonomic Group 4 species, and therefore can be used to inform taxonomic work on these species.
A NEW MAXIMUM-LIKELIHOOD TECHNIQUE FOR RECONSTRUCTING COSMIC-RAY ANISOTROPY AT ALL ANGULAR SCALES
Authors: Ahlers M. , BenZvi S. Y. , Desiati P. , Díaz–Vélez J. C. , Fiorino D. W. , Westerhoff S. 
Published: May 2016

ABSTRACT
The arrival directions of TeV–PeV cosmic rays show weak but significant anisotropies with relative intensities at the level of one per mille. Due to the smallness of the anisotropies, quantitative studies require careful disentanglement of detector effects from the observation. We discuss an iterative maximum-likelihood reconstruction that simultaneously fits cosmic-ray anisotropies and detector acceptance. The method does not rely on detector simulations and provides an optimal anisotropy reconstruction for ground-based cosmic-ray observatories located in the middle latitudes. It is particularly well suited to the recovery of the dipole anisotropy, which is a crucial observable for the study of cosmic-ray diffusion in our Galaxy. We also provide general analysis methods for recovering large- and small-scale anisotropies that take into account systematic effects of the observation by ground-based detectors.
SPECTROSCOPIC CONFIRMATION OF A PROTOCLUSTER AT z ≈ 3.786
Authors: Dey Arjun , Lee Kyoung-Soo , Reddy Naveen , Cooper Michael , Inami Hanae , Hong Sungryong , Gonzalez Anthony H. , Jannuzi Buell T. 
Published: May 2016

ABSTRACT
We present new observations of the field containing the z = 3.786 protocluster PC 217.96+32.3. We confirm that it is one of the largest known and most overdense high-redshift structures. Such structures are rare even in the largest cosmological simulations. We used the Mayall/MOSAIC1.1 imaging camera to image a 1.°2 × 0.°6 area (≈150 × 75 comoving Mpc) surrounding the protocluster’s core and discovered 165 candidate Lyα emitting galaxies (LAEs) and 788 candidate Lyman Break galaxies (LBGs). There are at least two overdense regions traced by the LAEs, the largest of which shows an areal overdensity in its core (i.e., within a radius of 2.5 comoving Mpc) of 14 ± 7 relative to the average LAE spatial density (

) in the imaged field. Further,

is twice that derived by other field LAE surveys. Spectroscopy with Keck/DEIMOS yielded redshifts for 164 galaxies (79 LAEs and 85 LBGs); 65 lie at a redshift of 3.785 ± 0.010. The velocity dispersion of galaxies near the core is σ = 350 ± 40 km s−1, a value robust to selection effects. The overdensities are likely to collapse into systems with present-day masses of >1015
M
⊙ and >6 × 1014
M
⊙. The low velocity dispersion may suggest a dynamically young protocluster. We find a weak trend between narrow-band (Lyα) luminosity and environmental density: the Lyα luminosity is enhanced on average by 1.35× within the protocluster core. There is no evidence that the Lyα equivalent width depends on environment. These suggest that star formation and/or active galactic nucleus (AGN) activity is enhanced in the higher-density regions of the structure. PC 217.96+32.3 is a Coma cluster analog, witnessed in the process of formation.
RE-ACCELERATION MODEL FOR RADIO RELICS WITH SPECTRAL CURVATURE
Authors: Kang Hyesung , Ryu Dongsu 
Published: May 2016

ABSTRACT
Most of the observed features of radio gischt relics, such as spectral steepening across the relic width and a power-law-like integrated spectrum, can be adequately explained by a diffusive shock acceleration (DSA) model in which relativistic electrons are (re-)accelerated at shock waves induced in the intracluster medium. However, the steep spectral curvature in the integrated spectrum above ∼2 GHz detected in some radio relics, such as the Sausage relic in cluster CIZA J2242.8+5301, may not be interpreted by the simple radiative cooling of postshock electrons. In order to understand such steepening, we consider here a model in which a spherical shock sweeps through and then exits out of a finite-size cloud with fossil relativistic electrons. The ensuing integrated radio spectrum is expected to steepen much more than predicted for aging postshock electrons, since the re-acceleration stops after the cloud-crossing time. Using DSA simulations that are intended to reproduce radio observations of the Sausage relic, we show that both the integrated radio spectrum and the surface brightness profile can be fitted reasonably well, if a shock of speed

∼ 2.5–2.8 ×

and a sonic Mach number

∼ 2.7–3.0 traverses a fossil cloud for ∼45 Myr, and the postshock electrons cool further for another ∼10 Myr. This attempt illustrates that steep curved spectra of some radio gischt relics could be modeled by adjusting the shape of the fossil electron spectrum and adopting the specific configuration of the fossil cloud.
THE WATER ABUNDANCE OF THE DIRECTLY IMAGED SUBSTELLAR COMPANION κ AND b RETRIEVED FROM A NEAR INFRARED SPECTRUM
Authors: Todorov Kamen O. , Line Michael R. , Pineda Jaime E. , Meyer Michael R. , Quanz Sascha P. , Hinkley Sasha , Fortney Jonathan J. 
Published: May 2016

ABSTRACT
Spectral retrieval has proven to be a powerful tool for constraining the physical properties and atmospheric compositions of extrasolar planet atmospheres based on observed spectra, primarily for transiting objects but also for directly imaged planets and brown dwarfs. Despite its strengths, this approach has been applied to only about a dozen targets. Determining the abundances of the main carbon- and oxygen-bearing compounds in a planetary atmosphere can lead to the C/O ratio of the object, which is crucial for understanding its formation and migration history. We present a retrieval analysis of the published near-infrared spectrum of

b, a directly imaged substellar companion to a young B9 star. We fit the emission spectrum model utilizing a Markov Chain Monte Carlo algorithm. We estimate the abundance of water vapor, and its uncertainty, in the atmosphere of the object. In addition, we place an upper limit on the abundance of CH4. We qualitatively compare our results with studies that have applied model retrieval on multiband photometry and emission spectroscopy of hot Jupiters (extrasolar giant planets with orbital periods of several days) and the directly imaged giant planet HR 8799b.