Rotational Structure Research Articles

UFO‐Shaped Integrated Triboelectric Nanogenerator for Water Wave Energy Harvesting

AbstractThe triboelectric nanogenerator (TENG), which is suitable for low‐frequency and high‐entropy mechanical energy harvesting, has great advantages in ocean energy collection and potential blue energy applications. The rational structural design can ensure the best working state of TENG in complex marine environment. Herein, an unidentified flying object (UFO) shaped integrated triboelectric energy harvester (U‐TENG) is proposed for complex and random ocean wave energy harvesting. The U‐TENG is assembled in a vertical structure by combining a coping TENG in a rotational structure and a bottom TENG in a rolling‐ball design. The proposed vertically integrated TENG structure can increase the efficiency of space utilization and improve the entirety output performance compared with the single device structure. A sophisticated auxiliary facility has also been pioneerily designed to simulate the ocean waving during the experiment tests. The prepared U‐TENG can easily light up dozens of light emitting diodes and power a commercial hygrothermograph at a low operating frequency. This work provides a highly efficient means to the development of high‐performance and robust TENG for ocean energy harvesting.

High-Roll-Off-Rate Ultrathin Polarization-Rotating Frequency Selective Surface

This letter introduces a transmission FSS with excellent roll-off feature, ultra-thin thickness, low insertion loss and wide rejection bands. Three novel basic component structures are developed based on the polarization rotator (PR) structure leading to multi-transmission zeros and poles which can be independently controlled. Theoretical analyses and simulations are carried out, and a prototype is fabricated and measured. The proposed FSS exhibits double sharp roll-off sidebands, ultra-thin thickness and low insertion loss, as well as two wide stopbands. In addition, the proposed FSS shows stable responses with oblique incidence up to 45 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^\circ$</tex-math></inline-formula> . As a result, the tight agreement between measurement and simulation validates the design principle.

High-resolution absorption spectroscopy of room-temperature and jet-cooled ammonia between 59,000 and 93,000 cm−1

We present new high-resolution photoabsorption spectra of ammonia spanning the region between 59,000 cm−1 and 93,000 cm−1 that were recorded by using the Fourier Transform Spectrometer at the Synchrotron SOLEIL. This region extends from just above the Franck-Condon envelope for the Ã1A2″ ← X̃1A1′ transition to well above the NH3+X̃+2A2″ ionization threshold. The spectra were recorded at a measured resolution of 0.23 cm−1 in both a room-temperature cell (293 K) and in a slit-jet supersonic expansion (∼70 K). The absolute photoabsorption cross section with an uncertainty of ± 5% is also reported for the room-temperature spectrum. The present resolution is a factor of 10 – 100 times higher than in other recently reported broad band spectra of ammonia, and many of the observed bands show partially resolved rotational structure. We have attempted to assign this structure for a number of these bands. The oscillator strengths extracted from the data are in good agreement with previous measurements but, in the case of structured bands, the present higher resolution measurements return higher peak absorption cross sections, that increase further when the sample is cooled. The present higher resolution spectra suggest that a number of previous vibronic band assignments that were based on quantum defect considerations may require some revision. Finally, we discuss the substantial differences between the photoabsorption and photoionization data just above the first ionization threshold.

Control of rotation angles of multilayer graphene on SiC (000) by substrate off-direction and angle

Graphene on SiC (000) tends to grow in multiple layers and does not have a single orientation relation with the SiC substrate. It has been considered impossible to control the rotation angle of multilayer graphene on SiC (000). In this study, we grew graphene on off-axis SiC substrates with various off angles from 0° to 8° and investigated their in-plane rotation and electronic structures systematically. As the off angle toward the [110]SiC direction increased, graphene rotated by 30° with respect to SiC became less dominant and instead, graphene rotated by 30 ± 2.5° appeared. We also found that the uniformity of the graphene rotation angle was relatively high on SiC substrates with a small off angle toward the [100]SiC direction. Our results suggest that the step-terrace structure defined by the substrate off-direction and angle plays an important role in the controllability of the rotation angle of graphene.

High resolution FTIR spectrum of CH2D37Cl: ν4 and ν8 fundamental bands

The high-resolution Fourier transform infrared spectrum of CH2D37Cl has been analyzed in the region of the ν4 and ν8 bands from 1170 to 1370 cm−1. The upper states of these fundamentals, separated by 0.6 cm−1, interact with each other by a-type as well as b-type Coriolis resonance, and a strong asymmetric distribution of the intensity of the rotational structure in each band is observed. The spectral analysis resulted in the assignment of 2774 and 1611 rovibrational transitions for ν4 and ν8 bands, respectively, which have been simultaneously fitted using Watson's A-reduction Hamiltonian in the Ir representation and the relevant perturbation operators. A set of spectroscopic constants for the two fundamentals as well as seven coupling terms have been determined. From spectral simulations, the dipole moment ratio |Δµa/Δµb| of ν4 has been determined to be 1.3 ± 0.1 while the intensity ratio between ν4 and ν8 has been estimated to be 5.0 ± 1.0.

Exploring role of aspect ratio for compressible flow in a rectangular lid-driven cavity with a vertical temperature gradient

Numerical investigation of a compressible fluid in a two-dimensional rectangular lid-driven cavity (LDC) with a vertical temperature gradient is performed by solving the compressible Navier–Stokes equation. Here, we explore the role of aspect ratio (AR) (width/height) on the vorticity dynamics and redistribution by considering three ARs of 1:1, 2:1, and 3:1. The onset and propagation of the instability are explored via time-resolved and instantaneous distributions of vorticity, time-series of streamwise velocity, and its associated spectra. The flow physics reveal that the precessing vortical structures in certain square sub-cells of the rectangular LDC resemble that of orbital motion with a primary core eddy surrounded by gyrating satellite vortices, typical of a supercritical flow in a square LDC. Upon increasing the AR, there is a major shift in the vorticity transfer from the top right corner (acting as the source of maximum vorticity generation) toward the left square sub-cells in the domain. This is further aided by the convective motion due to the imposed destabilizing vertical thermal gradient. The spectra demonstrate that a multi-periodic, chaotic flow is the consistent flow feature for the rectangular LDC for Re = 5500, irrespective of the AR. The compressible enstrophy budget of the rectangular LDC with varying AR is computed for the first time. This shows the dominance of the baroclinic vorticity over the viscous diffusion terms, which was conceived of as the major contributor to the creation of rotational flow structures.

Space-Time Thermal Binary Coding by a Spatiotemporally Modulated Metashell

The recently proposed space-time-coding electromagnetic metasurface introduces the temporal dimension into artificial structure design, greatly expanding its digital application in information processing. However, the counterpart in thermal digital metamaterial is still lacking but compelling because the absence of temporal dimension prohibits synergetic modulation of thermal signal in time and space, thus limiting the capacity of information storage and the efficiency of information transmission with heat. Here, we introduce the temporal modulation into existing spatially variable thermal coding structures and propose a space-time thermal binary coding scheme. We design a category of coding units with time-dependent metashells so that they can switch their functionalities between cloaking and concentrating in time sequences. Integrating these identical units on a two-dimensional spatial array, we numerically show that this single metasurface can output various digital signal sequences composed of 0 and 1 in time and space dimensions. We further experimentally realize the temporal modulation with a rotatable concentric multilayered structure driven by a time-stepping motor. These results demonstrate a practical space-time strategy for thermal binary coding, provide a feasible prototype for spatiotemporal regulation of thermal signal, and promisingly open an alternative way for realizing information processing in diffusion systems.

Barrier to Methyl Internal Rotation and Equilibrium Structure of 2-Methylthiophene Determined by Microwave Spectroscopy

The microwave spectrum of 2-methylthiophene was recorded in a frequency range from 2 to 26.5 GHz using a molecular-jet Fourier transform microwave spectrometer with a Fabry–Pérot type resonator chamber and coaxial arrangement of the resonator and the molecular beam. Measuring and assigning spectra of the 34S and 13C isotopologues allowed the determination of the semiexperimental equilibrium structure (reSE). Comparing the structure to that of thiophene revealed a decrease in the ∠(S−C2−C3) angle from 111.595(6)° to 111.37(1)° by addition of the methyl group to the C(2) position, as well as an increase in the S−C2 bond length from 1.7102(1) Å to 1.7219(2) Å. A–E splittings from internal rotation of the methyl group were observed, and the V3 potential in the vibrational ground state was determined to be 197.7324(18) cm−1. The V3 value and the rotational constants A, B, C were calculated with a large number of different methods and basis sets for benchmarking purposes by comparing them to the fitted parameters. The V3 value was also compared to those of other thiophene and furan derivatives to gain a better understanding of the steric and electrostatic effects in these classes of compounds.

Robot sensing based on electrical capacitance tomography sensor with rotation

The existing sensing technology for industrial robot hands cannot sense inside of an object. To recognise the material and internal distribution of an object when it is grasped, electrical capacitance tomography (ECT) may be used if the object is non-conductive, as ECT can measure the permittivity distribution inside an object from external capacitance measurements. An ECT sensor normally has 8 or 12 electrodes equally distributed around an object. This paper introduces the first attempt to make use of ECT with robot hands. Because the number of electrodes is limited, it is necessary to rotate the object to be imaged mechanically, so that sufficient measurements can be taken. Four aspects of the ECT sensor are discussed based on simulation: (1) the structure of electrodes; (2) the number of rotation times; (3) the starting position of rotation; and (4) the diameter of rotation. Two image reconstruction algorithms are used: the linear-back projection and Landweber iteration with three typical distributions. The results show that the rotational three-electrode ECT structure has good ability to produce useful images, showing the internal distribution of unknown objects.

Coexistence of single-particle and collective excitation in Ni61

The high spin states in 61 Ni have been studied using the fusion evaporation reaction, Ti( $^{14}$C,3n) $^{61}$Ni at an incident beam energy of 40 MeV. A Compton suppressed multi-HPGe detector setup, consisting of six Clover detectors and three single crystal HPGe detectors was used to detect the de-exciting $\gamma$ rays from the excited states. The level scheme has been extended up to an excitation energy of 12.8 MeV and a tentative J$_{\pi}$ = 35/2$^+$ . The low-lying negative parity levels are found to be generated by single particle excitation within the f p shell and also excitations to the g$_{9/2}$ orbitals as explained well with shell model calculations using the GXPF1Br+V M U (modified) interaction. Two rotational structure of regular E2 sequences with small to moderate axial deformation have been established at higher excitation energy. Most interestingly, two sequences of M1 transitions are reported for the first time and described as magnetic rotational bands. The shears mechanism for both the bands can be described satisfactorily by the geometrical model. The shell model calculation involving the cross shell excitation beyond the fp shell well reproduce the M1 and E2 sequences. The shell model predicted B(M1) values for the magnetic rotational band B1 show the decreasing trend with spin as expected with closing of the shears.

Enhanced Ferroelectric Polarization in Epitaxial BiFeO3−BiMg2/3Nb1/3O3 Films

Remanent polarization is a key parameter of a ferroelectric material. A large remanent polarization is favorable for various ferroelectric applications. Here, we report a large remanent polarization of 116.8 \ensuremath{\mu}C ${\mathrm{cm}}^{\ensuremath{-}2}$ observed in ${\mathrm{Bi}\mathrm{Mg}}_{2/3}{\mathrm{Nb}}_{1/3}{\mathrm{O}}_{3}$ (BMN)-modified ${\mathrm{Bi}\mathrm{Fe}\mathrm{O}}_{3}$ (BFO) thin films, epitaxially deposited on (001)-oriented ${\mathrm{Sr}\mathrm{Ti}\mathrm{O}}_{3}$ substrates buffered with ${\mathrm{La}}_{2/3}{\mathrm{Sr}}_{1/3}{\mathrm{Mn}\mathrm{O}}_{3}$ electrodes. Combined experimental analyses and first-principles calculations reveal that the incorporation of 10 mol % BMN into BFO increases both the intrinsic and extrinsic contributions, resulting in doubled polarization. The intrinsic polarization calculated for BFO-BMN is larger than that of BFO due to enhanced ionic displacements. Compared with epitaxial BFO films in a rhombohedral structure with an interaxial angle of \ensuremath{\alpha} = 89.72\ifmmode^\circ\else\textdegree\fi{} and quasitetragonal c/a = 1.018, the epitaxial BFO-BMN films become more tetragonal-like, with \ensuremath{\alpha} = 89.91\ifmmode^\circ\else\textdegree\fi{} and c/a = 1.037. Moreover, a unique rotated twinning-domain structure is developed in the BFO-BMN thin films, further increasing the out-of-plane polarization by rotating the [111] direction toward the film's normal. These results provide additional opportunities to increase ferroelectric polarization through composition engineering.

Wood product differentiation in age-structured forestry

We develop the classic market-level, age-structured forest model by extending the description of forestry output from homogenous wood to a set of differentiated outputs such as sawlogs and biofuels. The extension changes several most established results on the long-run sustainable market equilibrium of forestry. We show the existence of an optimal steady state with two (or more) simultaneous rotation periods. This equilibrium yields a smooth timber flow without normal forest structure and thus deviates from existing normal forest results as well as results on equilibrium cycles. We further show that the optimal rotation structure depends on wood product demand and the demand for land outside forestry, another feature that is absent in previous model formulations.

Nuclear Motion Is Classical: Spectra of Hydrogen Chloride and Ammonia

The concept of classical nuclear motion is extremely successful in describing motion at the atomic scale. In describing chemical reactions, it is even far more convincing than the picture obtained by using the Schrödinger equation for time development. However, this theory must be subject to critical tests. In particular, it must be checked if vibrational and rotational spectra are obtained correctly. Particularly critical are the spectra of small molecules containing the light hydrogen atom, since they have a distinctive rotational structure. The present study presents computations of the spectra of ammonia and hydrogen chloride using ab initio molecular dynamics, that is, by describing nuclear motion classically.

Switchable multi-wavelength actively Q-switched erbium-doped fiber laser based on nonlinear polarization rotation and Sagnac filter

This letter describes a switchable multi-wavelength actively Q-switched erbium-doped fiber (EDF) ring laser based on nonlinear polarization rotation (NPR) structure with Sagnac filter and electro-optic modulator (EOM). The intensity-dependent loss (IDL) generated by the constructed NPR structure can suppress the mode competition caused by EDF, combined with a comb filter Sagnac loop which composed of only 2-m-long polarization maintaining fiber (PMF), the constructed laser generates nine-wavelengths laser output with a constant wavelength interval of 3 nm. When the NPR structure is removed, the constructed laser generates quadruple-wavelengths laser output with 3 nm constant wavelength interval. It is proved that the effect of the NPR can suppress mode competition to achieve multi-wavelength laser output. In the laser with the constructed NPR structure, the nine-wavelengths laser output has a maximum wavelength shift of 0.21 nm and a maximum power fluctuation of 0.69 dB, while when the NPR structure is removed from the constructed laser, for the quadruple-wavelengths laser output, the maximum wavelength shift is 0.16 nm and the maximum power fluctuation is 0.29 dB. When the constructed laser with or without NPR structure, the minimum Q-switched pulse width and maximum average output power are 1.42 μs, 1.24 μs and 3.2μW, 10.2μW, respectively.

A 10-Year Follow-up Survey of Psychiatry Resident Education in Consultation-Liaison Psychiatry.

In 2010, the Academy of Consultation-Liaison (then Academy of Psychosomatic Medicine) surveyed US residency programs to understand training in consultation-liaison (CL) psychiatry, leading to recommendations in 2014. Since then, residency training in CL has evolved in the context of competing training demands, increased prioritization of electives, and reactions to coronavirus2019. To determine the current state of residency training in CL across the United States, including the structure of core and elective resident rotations in CL, attending physician staffing, presence of fellows and other trainees, didactic curriculum, and impact of coronavirus2019. Members of the Academy of Consultation-Liaison Residency Education Subcommittee designed and piloted an 81-question survey tool that was sent to program directors of 269 US general psychiatry training programs for voluntary completion. One hundred three of 269 programs responded to the survey, yielding a response rate of 38.3%. Responding programs were larger and more likely to have a CL fellowship than nonresponding programs. Of the 103 responding programs, 82.5% have more than the minimally required time on CL, with 46.6% reporting an increase in total CL time in the past decade. Since 2010, 18.4% of responding programs changed the placement of the CL rotation, with 43.7% now adherent to the 2014 Academy of Psychosomatic Medicine recommendation to include core CL training in the second half of residency. Thirty-five percent of responding programs require residents to rotate on more than 1 CL service, and 19.4% have a required outpatient CL component. Faculty full-time equivalent varies widely. Of all services included, 33.8% report that all CL faculty are board-certified in CL psychiatry, whereas 18.7% have no board-certified faculty. Of the 103 responding programs, 36.9% offer a CL fellowship, but 31.1% report no residency graduates pursuing CL fellowships in the past 5 years. Of the included programs, 77.7% have a formal CL curriculum for residents, with 34.0% reporting a separate didactic series during the CL rotation. Among the responding programs, the amount of time spent on core CL rotations has increased in the past decade, but programs have also shifted CL training earlier in the course of residency. Residency programs are increasingly challenged to provide an optimal CL experience, and updated guidance from Academy of Consultation-Liaison may be appreciated.

Detection of Carbon Monoxide’s 4.6 Micron Fundamental Band Structure in WASP-39b’s Atmosphere with JWST NIRSpec G395H

Carbon monoxide (CO) is predicted to be the dominant carbon-bearing molecule in giant planet atmospheres and, along with water, is important for discerning the oxygen and therefore carbon-to-oxygen ratio of these planets. The fundamental absorption mode of CO has a broad, double-branched structure composed of many individual absorption lines from 4.3 to 5.1 μm, which can now be spectroscopically measured with JWST. Here we present a technique for detecting the rotational sub-band structure of CO at medium resolution with the NIRSpec G395H instrument. We use a single transit observation of the hot Jupiter WASP-39b from the JWST Transiting Exoplanet Community Early Release Science (JTEC ERS) program at the native resolution of the instrument (R ∼ 2700) to resolve the CO absorption structure. We robustly detect absorption by CO, with an increase in transit depth of 264 ± 68 ppm, in agreement with the predicted CO contribution from the best-fit model at low resolution. This detection confirms our theoretical expectations that CO is the dominant carbon-bearing molecule in WASP-39b’s atmosphere and further supports the conclusions of low C/O and supersolar metallicities presented in the JTEC ERS papers for WASP-39b.

Wideband Dual-Polarized Differential-Fed Filtering Microstrip Patch Antenna with High Suppression and Wide Stopband

This paper presents a wideband dual-polarized filtering antenna with high suppression level and wide stopband. In the proposed antenna, the driven patch operates in a TM10 mode with an inherent radiation null caused by a higher mode TM12. Four dual-strip structures connected with the feeding probes are placed below the driven patch to achieve the capacitive coupling, thus resulting in a low-frequency radiation null with a sharp roll-off rate. The introduction of the parasitic patch and strips generates an in-band resonance and two high-frequency radiation nulls, which widens the upper stopband. Four slots are etched on the driven patch to excite the third resonance, thus achieving the wide operation band. The prototype of the proposed antenna is fabricated. With four controllable radiation nulls, the out-of-band suppression levels are above 29 dB in low-frequency band greater than 1 GHz and above 21 dB in high-frequency band up to 7 GHz, respectively. Due to the three in-band resonances, a wide impedance bandwidth of 2.93-3.96 GHz with a fractional band of 30% is obtained. With the rotational symmetry structure driven by differential probes, the proposed dual-polarized antenna has a cross-polarization ratio better than 28 dB, a high polarization isolation above 43 dB, and a good peak gain about 9.9 dBi.

Transient response of vibration energy harvester incorporating inertial rotation structure

Transient response of vibration energy harvester incorporating inertial rotation structure

Investigating the Manufacturing Process of Heat-Treated Nb3Sn-CICC Conductor for CFETR CSMC Modules

The center solenoid model coil (CSMC) of the China fusion engineering test reactor (CFETR) requires a high heat treatment temperature of 650 °C, which would destroy the insulation layer by carbonization and cause coil failure. To avoid this, using the manufacturing technology and routine process of the ITER center solenoid coil as a reference, in this article, a solution is introduced that is applied for manufacturing the CFETR CSMC module. The coil is heat treated before insulation and after winding. A single turn of the heat-treated coil is separated and the wrapping turn insulation is applied, and then the separated layers are reversed back into the integrated coil. To manufacture the integrated coils, the heat-treated coils are molded. After heat treatment, the interlayer separation distance of the Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn cable-in-conduit conductor in the coil should satisfy the allowable strain range of the superconductor, which is crucial for designing the rotational support structure of the interlayer separation. In addition, to achieve the accurate final shape of the coil and meet the design requirements, as well as to ensure coil contour accuracy after layer by layer separation, the antideformation ability of the coil mold is a key research topic. Herein, mechanical properties of the key components were optimized and numerical calculations and ANSYS simulations were used for statistical analyses. Results from the analyses indicated that the equivalent stress on the device is less than the maximum permissible stress of the raw material. The device was manufactured and compared with a design mold. The overall deformation error was <5%, movement error of the electric frame was <2%, rotation error of rotating was less than ±1° per 360°, levelness between the upper and lower platform was <1 mm, and motion error was less than ±1 mm per 100 mm. These results demonstrated the optimized structure design of the device. In the as-obtained device, the coil could separate a single turn and wrapping turn insulation could be applied. Parameters of the manufactured coil satisfied all the CSMC design requirements; these results indicate that the proposed device is suitable for manufacturing the CFETR CSMC module coil.

The Effect of Job Rotation and Changes in Organizational Structure on Employee Performance through Organizational Commitment as an Intervening Variable Study of KPP Pratama Pati Employees

This study analyzes the effect of job rotation and organizational structure changes on employee performance with organizational commitment as the intervening variable. The research data uses primary data in the form of a questionnaire. The method of determining the sample using purposive sampling and obtained a sample of 110 respondents. The data analysis used in this study is a structural equation model. The results of this study state that job rotation and changes in organizational structure have a positive effect on organizational commitment. The results of this study also state that changes in organizational structure and organizational commitment have a positive effect on employee performance, job rotation has no effect on employee performance.