Second Sound Research Articles

The Four-Wave Mixing and the Hydrodynamic Excitations in Smectic A Liquid Crystals

Abstract A nondegenerate four-wave mixing (FWM) on a new type of Kerr nonlinearity determined by the layer deformations in smectic A liquid crystal (SmA) is considered. It is shown that in the case when the frequency difference of the coupled electromagnetic waves (EMW) is close to the frequency of the second sound (SS), a strong parametric coupling among EMW through the dynamic grating of layer deformations occurs. As a result EMW with the lowest frequency is amplified and EMW with the highest frequency is depleted, while the two EMW with the intermediate frequencies are compressed in space and their envelopes take the form of a spatial soliton. The explicit expressions of all amplitudes are calculated. The gain coefficient appears to be one order of magnitude greater than the one for stimulated scattering on an ordinary sound in organic liquids. The interaction of EMW with the specially selected frequencies and wave vectors gives rise to the analog of Brillouin enhanced FWM (BEFWM) resulting in the ampl...

Two-wave mixing on the cubic non-linearity in the smectic A liquid crystals

Abstract We present a theoretical study of two-wave mixing in smectic A liquid crystals (SALC) due to the resonant interaction of the electromagnetic (EM) waves through the second sound (SS), which is a new type of the cubic non-linearity. It is shown that a parametric amplification of one EM wave by the other occurs. Explicit expressions for the EM and SS wave amplitudes are obtained, which appear to be of the kink and transverse spatial soliton form, respectively. It is also shown that the SS wave creates flexoelectric polarization and space charge. The estimated gain is one or two orders of magnitude greater than the gain for the stimulated Brillouin scattering in isotropic organic liquids. The theoretical results obtained may be used as a basis for an experimental investigation of SS high frequency behaviour.

A HeI-HeII Interface and Second Sound Shock Waves near the Superfluid Transition

Etude basee sur le modele phenomenologique de Guinzburg-Landau dependant du temps. L'interface He I-He II et les ondes de choc du second son pres de la transition superfluide sont des solutions kinks des equations

Observation of second sound by means of forced thermal scattering

Observation of second sound by means of forced thermal scattering

Thermo- and Elasto-optic Parameters of NaF and Their Implications for Light Scattering from Second Sound

Thermo- and Elasto-optic Parameters of NaF and Their Implications for Light Scattering from Second Sound

Velocity of Second Sound inLi7F and NaI

Velocity of Second Sound in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi mathvariant="normal">Li</mml:mi></mml:mrow><mml:mrow><mml:mn>7</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>F and NaI

Triplication and Quadruplication of the Second Sound

Triplication and Quadruplication of the Second Sound

On second sound in materials with memory

Vor kurzem haben Gurtin und Pipkin eine allgemeine nichtlineare Theorie der Warmeleitung entwickelt, die vollstandig mit den Gesetzen der Thermodynamik vereinbar ist und in welcher Warmestorungen sich mit endlicher Geschwindigkeit ausbreiten. Wir erweitern hier diese Theorie auf verformbare Korper.

The fallacious T-wave and the second sound.

The fallacious T-wave and the second sound.

Второй звук в твердом теле

Второй звук в твердом теле

Dispersion and damping of second sound in non-isotropic solids

Dispersion and damping of second sound in non-isotropic solids

On the detection of second sound in crystals by light scattering

On the detection of second sound in crystals by light scattering

The velocity of second sound below1° K

The velocity of second sound below<i>1</i>° K

First in Second Sound

First in Second Sound

An unusual bacillus from a case of bacterial endocarditis

The patient was a thirty-five-year-old woman when first seen in the clinic. At the age of thirteen years she had tonsillitis and sore throats. These were followed by an attack of swelling, tenderness, and redness of several joints. Aseites and edema appeared after the acute attack of rheumatism. She was told she had heart disease. At the age of sixteen her tonsils were removed. She married at twenty-four years of age and went through two pregnancies, at twenty-six and thirty years, without di&ulty. The patient gained “15 pounds during the latter pregnancy and then voluntarily reduced her weight to 104 pounds. She never felt strong again and began to have mild dypsnea on exertion. During the five months prior to her admission to Billings Hospital she had several bouts of perspiration associated with sensations of chilliness. She had a cough that was productive of mucopurulent sputum for three weeks just before hospitalization. Although the patient was in bed she experienced dull aching pain over the precordium for a few days before admission. She also had pain in the right costovertebral angle and described her urine as being “unusually dark.” Several weeks before she was first seen a finger tip was tender and swollen. The admission examination revealed a sick-looking, undernourished, dyspneic woman whose temperature was 100.4” F. The pulse rate was lOd/min., the respiratory rate was ZO/min. and the blood pressure was 112/50. The diastolic range was poorly defined and may have been lower. Other salient features of the examination included scattered petechiae in the skin, a large, hyperactive heart and a large firm palpable spleen. The precordium heaved synchronously with the heart beat. A systolic thrill was palpable over the apex of the heart. The apical thrust was diffuse and prominent. The second sound was not heard at the aortic region. A loud systolic murmur was audible over the entire precordium. A short, faint diastolic murmur was detected over the aortic region replacing the second sound. The pharynx was not inflamed. The laboratory procedures gave the following results. On May 8, May 14, and August 5, 1936, blood cultures were taken. On each occasion a bacillus was obtained in pure culture. Agglutinations with the patient’s serum against the typhoid, paratyphoid and B. abortus groups were positive only with the E. typhoszcs antigen in a dilution of l/20. The others were entirely negative. Stereoscopic x-rays of the chest showed the heart to be “slightly less than 65 per cent over-size by film tracing.” Early congestive changes were reported in both lungs. Besides a tachycardia of lOO/min. an electrocardiogram showed broad P-waves in all leads and T, to be low in amplitude. The blood Kahn was weakly positive and the Wassermann was negative. From May 8 to May 15, 1936, while the patient was in the hospital, the leucocyte count varied from 9,100 to 11,100 cell/c.mm. The differential count showed a mild absolute increase in polymorphonuclear leucocytes. A moderate secondary anemia was present at all times.

Accentuated Aortic Second Sound

Accentuated Aortic Second Sound

On the accentuation of the second sound in the pulmonary area. Skoda’s sign

On the accentuation of the second sound in the pulmonary area. Skoda’s sign

On the accentuation of the second sound in the pulmonary area. skoda’s %n

On the accentuation of the second sound in the pulmonary area. skoda’s %n