Investigation of edge radiation intensification effect generated by periodic alignment of three-pole wigglers

The intensification effect of edge radiation due to the periodic alignment of three-pole wigglers was analytically and numerically investigated. The radiation properties were studied using a simple model that had an alternating alignment of straight sections and large gradient orbit sections due to the use of three-pole wigglers. The angular distribution of the radiation was concentrated on a concentric circle. The peak intensity of the radiation was roughly on the same order as that of the peak radiation of a planar undulator. The spectrum of the radiation had a characteristic structure that was rather similar to the higher harmonic structure of undulator radiation. A numerical study showed that a planar undulator with a specific K value satisfies approximately the radiation intensification condition due to the periodic alignment of the three-pole wigglers. The intensified edge radiation is included in the undulator radiation.

Vocal repertoire, harmonic structure, and behavioural context in Red-throated Loon (Gavia stellata)

Among the five loon species (Gaviidae), Red-throated Loon (Gavia stellata) is the oldest lineage and is the most divergent in morphology and vocalizations. We substantially expand earlier description of calls for a nesting pair and non-breeding birds on Haida Gwaii, British Columbia, Canada. Three major calls used by the nesting pair (Quack, Wail, Plesiosaur) were all low frequency (700–3000 Hz) with multiple harmonics, calls that were also used by non-breeding birds without territories that overnight on freshwater lakes. Call duetting in the Wail and Plesiosaur, as well as sexually dimorphic frequencies and structure within the duets, typically occur in territorial display or pair interactions. The nesting pair used several calls audible only at short distances (Coo, Extended Coo, Staccato, Soft Raack) that were low frequency (200–1200 Hz), graded in behavioural intensity and that resulted in chick responses, including feeding or return to nest. A high amplitude Loud Raack was used by the female and is associated with flight incentives for pre-fledged chicks. Vocalizations of chicks, usually feeding solicitations to the adults, develop from simple chirps in the first week following hatch to more complex calls resembling the Wail and the Plesiosaur calls just prior to fledging. Although the majority of our acoustical descriptions are limited to a single nesting pair where sexes could be differentiated, these represent the first quantification of sound frequency, harmonic structure, and duration, most often associated with context-specific responses, and are suggestive of syntactical content to the vocal repertoire of this basal taxon.

Local Deformation Behavior of the Copper Harmonic Structure near Grain Boundaries Investigated through Nanoindentation

The copper harmonic structure, which consists of a coarse-grained “core” surrounded by a three-dimensional continuously connected fine-grained “shell,” exhibits both high ductility and high strength. In the present study, dislocation interactions at the shell–core boundary in the copper harmonic structure were directly measured using nanoindentation and microstructural observations via kernel average misorientation (KAM) to further understand the reason for its excellent mechanical properties. KAM analysis showed that the dislocation density in the vicinity of the shell–core boundary within the core region gradually increases with increasing plastic strain. The variation in the nanohardness exactly corresponds to the KAM, indicating that the higher strength is primarily caused by the higher dislocation density. The critical load for nanoindentation-induced plasticity initiation was lower at the shell–core boundary than at the core–core boundary, indicating a higher potency of dislocation emission at the shell–core boundary. Because dislocation–dislocation interactions are one of the major causes of the increase in the flow stress leading to higher strain hardening rates during deformation, the excellent balance between strength and ductility is attributed to the higher potency of dislocation emission at the shell–core boundary.

The Harmonic Structure of the Focused Wave in a Wave Flume

In recent years, extreme waves have attracted more and more attention due to its threat to offshore and coastal structures. It is essential to obtain further insight into the formation and propagation of the extreme waves. The formation of extreme waves mainly comes from the simultaneous focusing of wave group energy in the ocean. In the present study, the nonlinear characteristics of the extreme wave are experimentally investigated by the wave focusing method. The phase decomposition methods, both two-phases separation and four-phases separation methods, are used to obtain the higher harmonic elevation in the focused wave. The results show that the four-phases separation method can reasonably extract the first four harmonics. With the separated results, the nonlinear analysis of the wave elevation and velocity of the focused wave is carried out. It is found that the harmonics of the wave group focused at the same time, but the wave elevation and energy of higher-order harmonics are smaller than that of the overall wave. The Stokes wave theory can describe the variation of second-order harmonics satisfactorily. However, the Stokes wave theory cannot estimate third-order harmonics accurately. More work should be carried out to figure out the third-order wave interaction occurring during wave focusing. With a distributed wave gauge system, the wave evolution along the wave flume is measured. The evanescent modes significantly influence the wave group’s harmonic structure near the wavemaker. The coefficients of the higher-order harmonics are obtained from the measured elevations. The nonlinear wave elevation of the focused wave can be reconstructed with those coefficients basing on the linear theoretical solution, which is in good agreement with the experimental results.

Relasitas Lakuan Wayang dengan Iringan Gamelan Gagrag Yogyakarta

ABSTRAKMaksud dari penulisan ini adalah mengadakan studi terhadap relasitas lakuan gerak wayang gaya pedalangan Yogyakarta dengan musik iringan wayang. Data diperoleh dari pengamatan dan survei pergelaran wayang yang diselenggarakan di Sasana Hinggil Dwi Abad Yogyakarta. Pendekatan masalah dengan metode deskriptif analitis, sedangkan untuk kepentingan pembahasan dengan menggunakan analisis estetika terutama estetika pewayangan. Berdasarkan analisis yang dilakukan, diketahui bahwa lakuan gerak wayang dengan iringan wayang membentuk jalinan harmonik. Gending iringan wayang meliputi bentuk gending ageng, ladrangan, ketawang, lancaran, playon dan sampak, sedangkan dari segi estetik memenuhi kesatuan atau keutuhan, kekuatan, dan kerumitan (unity, intencity, dan complexcity).Kata kuci: Pertunjukan wayang, relasi gerak wayang dan gamelan, struktur harmonik ABSTRACTThe purpose of this is to conduct a study of the behavior of Yogyakarta puppet style movements with puppet accompaniment music. Data obtained from observations and surveys of wayang performances held at Sasana Hinggil Dwi Abad Yogyakarta. Approach to the problem with the analytical descriptive method, while for the purpose of discussion using aesthetic analysis, especially puppet aesthetics. Based on the analysis carried out, it is known that the wayang movements with accompaniment form a harmonic structure. Puppet accompaniment gending includes the forms of gending ageng, ladrangan, ketawang, lancaran, playon and sampak, while in terms of aesthetics it takes care of unity or integrity, strength, and complexity (unity, intencity, and complexcity).Key word: Wayang performance, relation of movement and music, harmonic structure.

Groove in Cuban Son and Salsa Performance

Using a combination of ethnography, empirical measures of microtiming between rhythm-section musicians and ethno/musicological analyses, this article examines and measures groove in three real-world performances of the popular dance tradition of Cuban son and salsa. The findings paint a complex picture of groove that is shaped by rhythmic-harmonic structure, shared concepts of timing, individual preferences, group dynamics and rhythmic interactions between musicians as they work together to negotiate a groove with the ‘correct’ feel. Microtiming analyses produce a snapshot of how rhythmic timing relationships are ‘played out’ between musicians in live performances and provide quantitative measures of the level of synchrony and separation within the rhythm section. They also suggest that microtiming is influenced by certain metric locations within the rhythmic-harmonic structure, particularly those locations that anticipate harmonic changes and mark the beginning of repeated rhythmic-harmonic sequences.

Ratcheting-Fatigue Behavior of Harmonic-Structure-Designed SUS316L Stainless Steel

Stainless steels with harmonic-structure design have a great balance of high strength and high ductility. Therefore, it is imperative to investigate their fatigue properties for engineering applications. In the present work, the harmonic-structured SUS316L stainless steels were fabricated by mechanical milling (MM) and subsequent hot isostatic pressing (HIP) process. A series of ratcheting-fatigue tests were performed on the harmonic-structured SUS316L steels under stress-control mode at room temperature. Effects of grain structure and stress-loading conditions on ratcheting behavior and fatigue life were investigated. Results showed that grain size and applied mean stress had a significant influence on ratcheting-strain accumulation and fatigue life. Owing to the ultrafine grained structure, tensile strength of the harmonic-structured SUS316L steels could be enhanced, which restrained the ratcheting-strain accumulation, resulting in a prolonged fatigue life. A higher mean stress caused a faster ratcheting-strain accumulation, which led to the deterioration of fatigue life. Moreover, a modified model based on Smith–Watson–Topper (SWT) criterion predicted the ratcheting-fatigue life of the harmonic-structured SUS316L steels well. Most of the fatigue-life points were located in the 5 times error band.