Sympathetic Vibration Research Articles

The Microfluid-Driven Control by Forced Wave

The commutation of pressure, electro-osmosis and acoustic methods is usually adopted to realize the drive of microfluid in microsystem. However, the above methods do not have a very ideal controllability. In view of the above situation, the paper proposes a kind of microfluid-driven method according to physical mechanism of wave-vortex interaction. In the method the microfluid-driven control is realized sympathetic vibration between forced wave and unstable wave in the vortex layer to intensify or destroy nonlinear stability of vortex or to regulate quasi-vortex energy flow in the boundary layer, in which the forced wave is produced by applying tangential simple harmonic motion with specific frequency and amplitude to the outside of flowing passage or flowing body. The paper demonstrates the method theoretically, and then uses an experiment to prove its availability. By using de-ionized water, straight round glass with the diameter of Φ18~Φ20μm, the experiment of separation is carried out successfully. The method has very broad applying prospect for the activity retention in the process of cell injection and transfer in the biomedical field and the fuel transfer in the micro propeller.

Modal Analysis of Temporarily Installed Suspended Access Equipment Based on ANSYS

The paper chooses ZLP800 temporarily installed suspended access equipment (TISAE) as a object of study, it is based on theory of structural model analysis. The finite element model has been established by the finite element method (FEM). The model is analyzed by the modal analysis module of ANSYS, the first four natural frequencies and corresponding modal shapes are extracted in this paper, the cause of every modal shapes are analyzed in the paper. In order to get a more rational constraint mode, the natural frequency under different constraint condition is calculated. Then the external excitation factors, such as the vibration frequency of the electrical machine in a hoister, swing of suspended platform and the friction disk in a hoister are calculated respectively, finding the external excitation factors which would cause a sympathetic vibration, and giving the suggestions for averting the sympathetic vibration, providing some academic reference to improve and perfect the structure design of the TISAE products.

Experimental investigation and performance analysis of a dual-cylinder opposed linear compressor

The dual-cylinder opposed linear compressor (DOLC) contains a couple of symmetrical gas loads on the two sides of the movement components. Because the gas loads are symmetrical, the balanced position of movement components will not be offset by gas force during the operating process, and piston displacement can be detected and controlled more easily. Based on the kinetics and thermodynamics theory, the non-linear gas load of the DOLC was linearized by the Fourier method. The relationship between the supply voltage and displacement is presented. Through air compression experiments, the operation features of the DOLC with different syntonic spring groups were analyzed. The performance of the DOLC was considerably affected by work conditions and the stiffness of syntonic spring groups; the closer the work condition was to the sympathetic vibration, the higher the observed efficiency of the DOLC. A jump, hysteresis, and an unstable phenomenon in the process of voltage regulation occurred around sympathetic vibration conditions. In the process of increasing voltage on a certain discharge pressure condition, the displacement jump phenomenon occurred when the intrinsic frequency approacheds power frequency, causing the discharge pressure to drop synchronously. In the process of decreasing voltage on the lower discharge pressure condition, the displacement shrink phenomenon occurred when the intrinsic frequency approached power frequency. Because sympathetic vibration conditions changed with discharge pressures, a hysteresis district existed between the displacement jump point and shrink point. The DOLC worked unstably on the hysteresis district because the discharge pressure fluctuated between the two values. To make the DOLC work stably on higher efficiency, the intrinsic frequency should be configured to a slightly larger value than the power frequency by setting the syntonic spring groups and the mass of movement components to the ratings on the work conditions. Controlling the power frequency after is needed to adhere to the intrinsic frequency of the variable work conditions.

Simulation Analysis and Experiment Research for a Large Span and Heavy Load Crossbeam

Aiming at solving issues of load bearing deformation compensation and sympathetic vibration, this paper takes a large span and heavy load crossbeam of a domestic heavy-type numerical control milling planer for research object, the final purpose is to improve machining precision and stability of the heavy machine tool product. The load curve considering the influence of columns deformation, natural frequency and vibration model are obtained, respectively by the dynamic and static simulation analysis of the crossbeam with the finite element analysis method. Then, the modal analysis results are verified through the model experiment. Lastly, this paper presents an approach by estimating the load curve to improve machining precision, points out the weak links, and provides guidance for crossbeam structure design, optimization and reverse manufacture.

Sea keeping analysis of air cushion vehicle with different wave angles under the operation resistance

The air cushion vehicle (ACV) sea keeping characteristic under different wave directions with the operation resistance is discussed with the couples of the heave, pitch roll motion and the pressure of the cushion. In previous researches, only wave and cross wave direction were discussed. Then a Matlab program is made to calculate the united frequency responses of heave, pitch and roll amplitude of the craft, under different wave frequencies and different wave directions. The results of the research depict some dangerous situations under which the sympathetic vibration happens in heave, pitch and roll motion and the amplitudes are extremely higher than those under the ordinary conditions. These results will be helpful in ACV design and operation.

Cantata of Fire: Son et lumière in Waco Texas, auscultation for a shadow play

Strategically placed with the right degree of persistence and ‘sympathetic vibration’, sound can reveal itself as a potentially devastating force. As used against the Branch Davidian religious sect in 1993 at Waco Texas, the FBI’s little remembered ‘sonic assault’ – involving Tibetan monks in prayer, dentist drills, and other bizarre recordings – arguably contributed to the tragic denouement of events as they were witnessed live on TV by millions around the world. The use of sustained, high-pitched, loud or repetitive noises and music added to an already incendiary narrative endgame, established first by the sect but later supported by the media. This essay draws on this tragic event, and later ‘forensic’ research conducted by the author in the process of writing, scoring and producing an audio performance work, Cantata of Fire. Specifically, it explores the way in which amplified ‘concrete’ sound and electronic ‘viral’ voices were used as a weapon at Waco – materially, psychologically, theatrically and ‘diegetically’. And in the context of a much longer (and repressed) history of sound as used in ‘theatres of war’ and other conflicts, the author reconsiders the overlooked and underestimated powers of sound, music and noise in an age dominated by digital ‘real-time’ electronic media and ‘tele-visual’ surveillance.

Spatiotemporal analysis of Tsunami wave property and hazardous sea area in Seto Island Sea

Tsunami disaster prevention of Seto Inland Sea is slow to take action for lack of knowledge of generation mechanism of Tsunami damages. According to previous research papers, there is a possibility of appearance of sudden water level raising and long-term water level fluctuation in sympathetic vibration with characteristic vibration in some bay. Therefore, this study focuses on period characteristics and hazardous sea area. As a result of numerical analysis, temporal period characteristics of each sea area, distribution of largest tsunami heights and time of occurrence, distribution of maximum tsunami velocity and time of occurrence and a map of hazardous sea area are clarified. Moreover, generation mechanisms of Tsunami damages are examined.

3103 新幹線車両用腰掛の振動特性について(OS1-2乗り心地と振動特性,OS1 交通・物流システムの高速化,利便性,快適性の向上,オーガナイズド・セッション)

Vertical vibration (including high frequency vibration) of Tokaido-Shinkansen is tangible with the improved lateral riding comfort, maximum speed and body stiffness. However the seat for Shinkansen that can suppress high frequency vibration effectively isn't developed, because it isn't clear why vibration on several parts of the seat is greater than that on the floor. Therefore we investigated the vibration characteristic of the seat for Shinkansen, both the seat frame and the cushion, using Vehicle Dynamic Simulator. The results show that because of the sympathetic vibration of the cushion and the seat frame, vibration on the seat is increased compared with that on the floor.

A210 g-ジッターシミュレータにおける液柱振動挙動の可視化計測

Thermocapillary (or Marangoni) convection in a cylindrical liquid bridge and its transition to oscillatory and chaotic states has been stimulating strong interest among fluid dynamicist in the microgravity community. To clarify the mechanism of such a phenomenon, microgravity experiment will be carried out in the International Space Station (ISS) and several parameters (Dynamic Surface Deformation (DSD), temperature, mode structure, etc.) of liquid bridge will be measured. But g-jitter in ISS might have harmful influences on the measurement and thermocapillary flow. So, in this experiment, g-jitter is reproduced on the ground by using piezo-electric actuator (PZA) and feedback control system and DSD and flow pattern are observed. As the result, influence of g-jitter is removed by image processing and signal filter, and it is clarified that g-jitter has little effect on the mode structure. In addition, resonant frequencies of liquid bridge are observed and it has little probability that g-jitter causes sympathetic vibration of liquid bridge.

An infrared radiation study of the biophysical characteristics of traditional moxibustion

Moxibustion has been a part of acupuncture practice for thousands of years. Traditionally, it includes direct moxibustion, in which moxa sticks are burned at acupuncture points on the skin, and indirect moxibustion, in which monkshood cakes or ginger or garlic slices are used to insulate the skin from burning moxa cones. Recently randomised clinical trials and clinical observations suggest that moxibustion can enhance physiological and immune functions, but there has been little investigation of the scientific basis of these traditional techniques. The present study compared the infrared radiation caused by these techniques to that of non-specific controls and to that of the human body surface at an acupuncture point. A highly sensitive, infrared-spectrum detection device was used to compare the spectra of traditional moxibustion materials (n = 4/group) with those of control materials (n = 4/group) and to the spectrum at the surface of an acupuncture point LI 4 (Hegu) in healthy volunteers (n = 7). The infrared radiation intensity produced by a traditional moxa stick was 43300.41 mV, with a peak on the infrared spectrum of 3.5 microm, while the respective radiation intensities of two controls, a smokeless moxa stick and a 555 cigarette, were 31.15 mV and 37.03 mV with peaks of 7 microm and 3.5 microm. The infrared radiation intensities of the three traditional media of indirect moxibustion, monkshood cake, ginger slices and garlic slices, were 520.27 mV, 594.79 mV and 681.87 mV, respectively, all with peaks around 7.5 microm and similar spectra. In contrast, the infrared radiation intensities of slices of cucumber and carrot, used as control media for indirect moxibustion, were 274.47 mV and 50.53 mV, respectively, substantially different from those of the traditional media. Infrared radiation at LI 4 (Hegu) was 20.40 mV, and peaked on the infrared spectrum at about 7.5 microm. The experiment showed that the thermal action of the traditional moxa stick was more potent than that of indirect moxibustion and its radiation peak was different from that at the acupuncture point on the human body. In contrast, the thermal action of traditional indirect moxibustion was modest and its radiation peak matched that at the acupuncture point. Direct moxibustion with a traditional moxa stick may produce its potent therapeutic effects by thermal action, while traditional indirect moxibustion may act by producing modest thermal action and a sympathetic vibration at the skin surface. Non-traditional thermal materials and media may not be suitable substitutes for traditional materials. The data provide a scientific, biophysical rationale for traditional moxibustion.

Vibration Characteristics of the Human Spine Under Axial Cyclic Loads: Effect of Frequency and Damping

A nonlinear finite element model of lumbar spine segment L3-L5 was developed. The effects of upper body mass, nucleus injury, damping, and different vibration frequency loads were analyzed for the whole body vibration. To analyze the influence of whole body vibration on facets of lumbar spine and to analyze the influence of nucleus injury, upper body mass, and damping on the dynamic characteristics of lumbar spine. Many studies have investigated whole body vibration for lumbar spine. However, very few investigations analyzed the influence of whole body vibration on facets and vibration characteristics of the injured spine. The nonlinear finite element model of the L3-L5 segment was constructed based on the embalmed vertebra geometry and validated. Besides static and modal analyses, transient dynamic analyses were also conducted on the model with an upper body mass under damping and different frequency cyclic loads. In the period of human spine vibration, the vibration effects of different regions of the lumbar spine are not the same. Anterior regions of the L3-L5 segment show small vibration amplitudes, but posterior regions show large amplitudes. The vibration amplitude of facet contact force is more than 2.0-fold as large as that of displacement and stress on vertebrae or discs. To decrease the weight of the upper body will increase the resonant frequency. To remove the nucleus will decrease the resonant frequencies. The vibration displacement, stress, and facet contact force will reduce generally by 50% using damping ratio 0.08. The posterior regions of intervertebral discs of the lumbar spine are easy to injure during long-term whole body vibration compared to anterior regions. The vibration of human spine is more dangerous to facets, especially during whole body vibration approximating a sympathetic vibration, which may lead to abnormal remodeling and disorder of the lumbar spine.

Sympathetic vibration due to co-ordinated crowd jumping

Sympathetic vibration due to co-ordinated crowd jumping

Sound synthesis model incorporating sympathetic vibration of strings

Synthesizer models for emulating musical instruments are improved to take into account sympathetic string vibrations. One embodiment of the present invention scales an output signal from a sound synthesis model (220) and uses the scaled signal as an input signal for a number of single-string emulators (201-212) causing the single-string emulators to produce sound signals corresponding to sympathetic string vibrations. The output signals from the synthesis model (220) and from all of the single-string emulators (201-212) are added together. Another embodiment employs an octave's worth of single-string emulators to emulate the lower strings of an emulated instrument. Still another embodiment is a synthesizer which includes an input bus (220A) for accepting a sound signal, scaling means (244), a plurality of single-string emulators, and means for summing output signals from the string emulators. Embodiments preferably employ waveguide synthesis or the plucked string model to emulate single strings.

How things work: the physics of everyday life

How things work: the physics of everyday life

Cavitation phenomena and performance of oil hydraulic poppet valve. 2nd report Influence of the chamfer length of the seat and the flow performance.

The influences of the chamfer length of the valve seat on the flow performance and the cavitation phenomena of a oil hydraulic poppet valve were studied experimentally using the half cut model. It was made clear that the discharge coefficient became largest when the ratio of the chamfer length (S) and the restriction height (h) was a specific value in almost 1≤S/h≤3 in case of diverging flow, and S/h≤1in case of converging flow, when the valve lift X and Reynolds' number Re were constant. The critical cavitation number Kc also became largest at the same S/h as above. In case of diverging flow having chamfer length S=(1∼2.5)h, the periodic flow turbulence occured at the metering restriction under some pressure conditions. And the unusual sound noise like as whistling occured with the sympathetic vibration of the oil column in the pipe line.

American Nationalism as a Theory of Nature

HE epithets some twentieth-century Americans apply to western Europe (atheistic, socialistic, decadent, wornout) had their counterparts in the eighteenth century. They are only a continuing expression of the centuries-old tension between the Old and the New Worlds. The difference, however, is that in the eighteenth century it was America to which the derogatory adjectives were applied (degenerate, unhealthy, nauseous, monstrous). The quarrel arose over the interpretation of natural phenomena in America. Many Europeans believed nature in the New World was in its first stage of development, and the aboriginal human inhabitants were correspondingly primitive. The American, on the contrary, regarded American nature as extraordinarily vigorous, with the aboriginal as well as the colonial inhabitants partaking of this strength. The most influential European statement was made in the Histoire naturelle (i749) of Buffon, whose data and theories were repeated shortly afterwards in Diderot's Encyclopedie (1751). These great works furnished facts, misinformation, and ingenious guesses to two generations of controversialists. Their eloquence caused a sympathetic vibration in the British Isles, where there came to be a curious agreement with the French upon the woeful case of America. Why the British should have consented to defame the vast areas they had won from France in i763, as well as their own ancient possessions, can perhaps be explained only byrecalling the exigencies of theories of nature and human culture. The best known American rejoinder is in Jefferson's Notes on Virginia (1784), but there were many other responses that reveal a common conception of the young nation as not only an adaptation to, but an expression of the natural process. American nationalism in the writings of late eighteenth-century historians is a statement of a theory of nature put in political and cultural terms. The reports of the early Spanish and French explorations and establishment of the Jesuit missions (especially in the present southern United

The Harmonic Structure of Violin Tones

Violin tones covering the greater part of the playing range of the instrument have been subjected to harmonic analysis. The analyses included normal tones and “harmonics,” which were studied with a variety of technical playing conditions obtaining, for example, variable point of contact between bow, and string, sympathetic vibration of unstopped strings, constant pitch but with change of string, variable pitch on each string, and recording in a music studio and a “dead” room. The results show (1) that change in point of contact between bow and string effects a characteristic variation in harmonic structure; (2) that harmonic constitution varies with the introduction of sympathetic vibration of open strings; (3) that not only do tones of the same pitch played on different strings vary in harmonic structure but also different pitches played on the same string; (4) that the lower natural harmonics are not essentially different in structure from fully-stopped tones of the same pitch and same string; (5) that the higher natural and artificial harmonics are not pure tones but approach a much greater degree of purity than do most normal tones.

Tone perception in gammarus pulex

The proof of the existence of a restricted tonal sense in any animal would be of great interest. The present paper offers evidence of the occurrence of this phenomenon in the Gammarids. Though it must be admitted that the number of animals which responded to the tests was small, the response, when it occurred, was so definite and unmistakable that a description of the; results seems desirable. My attention was first directed to the matter by Miss Margaret Cussans, who was engaged at the time in working out, at my suggestion, the circulation of Gammarus pulex on the living animal under the microscope. We then noticed that this species responded only to the bass note of the College chime, which, giving on examination 240 vibrations per second, therefore corresponded to the B below middle C of the pianoforte. In the first place it must be noted that the animal responds (in water) only when imprisoned in the compressorium or live box. This makes the case the more interesting, since if the reaction had not been observed by the merest accident, the same experiments might have been conducted on the animals in their natural surroundings with absolutely negative results. They are compressed only so much as to prevent wandering, whilst leaving their appendages quite free. They may then be kept under observation on the stage of the microscope. I had a special live box constructed so as to permit a gentle stream of water being passed continuously through it. This prevents asphyxiation, and allows a single specimen to be experimented with for a. longer period than would otherwise be possible. It is, of course, inevitable that the vibrations should be conveyed to the animal by the medium in which it finds itself, and in this sense it is impossible to postulate true; audition (as usually understood) in any true aquatic species. The factor to eliminate here is clearly the specific period of the medium itself, the energetic vibration of which, in response to its own note, may vitiate the result of the experiment. For this reason I used three types of live box and microscope; without, however, any difference in the results being noticed. Further, the fact that the response is only evoked by a limited range of tone, and then without reference to any specific forced or sympathetic vibration of the surrounding medium, intimates that the stimulus is associated with a definite physiological status of the animal itself, since even if the box were an essential factor in the success of the test, we should still leave unexplained the differential response. It is, however, easy to show that the box itself, owing to its small size and heavy construction, is ill adapted for the transmission of vibrations, and is certainly the last means one would adopt to transmit aerial vibrations freely to the animal.

The Mechanics of the Inner Ear

THE University of Missouri has recently issued a memoir by Prof. Max Meyer, in which an interesting, instructive, and suggestive attempt is made to explain the mechanism of the cochlea without having recourse to the application of the principle of sympathetic vibration, or rather without the assumption that there exists in the cochlea, in the form of the organ of Corti, a vast number of delicate structures tuned, as it were, to tones of different frequencies. Prof. Max Meyer does not base his views on experimental data; his paper is a purely theoretical discussion as to how the cochlea may act, if we make six fundamental assumptions, none of which can, at present at all events, be tested by direct examination or by direct experiment. His inquiry begins with the movements, in and out, of the stapes at the oval window. The tube filled owith fluid is divided into three compartments, the upper, the scala vestibuli, communicating at the apex of the cochlea with the scala tympani, at the foot of which we find the round window, while between the two scalae we have the cochlear duct, or scala intermedia, composed, in its turn, on one side by the basilar membrane, on which rests the organ of Corti, and on the other by Reissner's membrane. When the base of the stapes is pushed inwards at the base of the scala vestibuli, pressure is communicated to the fluid in the scala; (the scalae communicating at the apex of the cochlea by a little opening, the helicotrema), and the membrane of the round window passes outwardst towards the tympanic cavity. It is ogenerally held that with such pressure the fluid in the oscalse moves as a whole, and that pressure is communicated to the whole length of the scala intermedia, and especially to the basilar membrane, and that in this way the nerve-endings in Corti's organ are also submitted to pressure. The question then arises, is there any differentiating mechanism in the basilar membrane or in Corti's organ for tones of different frequencies, or, in other words, have we here an organ capable of analysis? Some deny any such property, while others, since the views of Helmholtz were first promulgated, are of opinion that there does exist an analysing mechanism.

Scientific Serials

Scientific Serials