scholarly journals AN EXPERIMENTAL STUDY OF HARBOUR RESONANCE PHENOMENA

1988 ◽  
Vol 1 (21) ◽  
pp. 18
Author(s):  
F.M. Martinez ◽  
V.S. Naverac
Keyword(s):  
Experimental Study ◽  
Hydraulic Head ◽  
Head Loss ◽  
Long Waves ◽  
Resonant Response ◽  
Northern Spain ◽  
Experimental Conditions ◽  
Head Loss Coefficient ◽  
Series Of Experiments ◽  
Harbour Resonance

An extensive series of experiments has been carried out at the laboratory in order to study rectangular harbour oscillation excited by incident long waves. Attention is focused on the effect of head loss entrance on resonant response attenuation. A "gross" quadratic hydraulic head loss coefficient is defined and information about it, resulting from tests, is provided. Experimental conditions used in this piece of work seem to be realistic under suitable scaling for Northern Spain harbours.

Experimental Study on Increasing Magnetic Abrasive Finishing Efficiency of Finishing Nonferromagnetic Materials

2007 ◽  
Vol 359-360 ◽  
pp. 300-304
Author(s):  
Shu Ren Zhang ◽  
Li Feng Yang ◽  
Guo Xiang Wu
Keyword(s):  
Experimental Study ◽  
Surface Roughness ◽  
Magnetic Force ◽  
Magnetic Flux Density ◽  
Experimental Conditions ◽  
Magnetic Abrasive Finishing ◽  
Abrasive Particles ◽  
Abrasive Finishing ◽  
Series Of Experiments ◽  
Diameter Reduction

Magnetic Abrasive Finishing (MAF) is relatively a new finishing technique which employs the magnetic force for finishing. In this paper, the influence of the magnetic flux density on the finishing pressure and the finishing efficiency during finishing is analyzed. With the cylindrical magnetic finishing apparatus developed by the author, a series of experiments on finishing the cylindrical surfaces of nonferromagnetic materials and ferromagnetic materials are carried out. To solve the problems of low finishing efficiency and abrasive particles escaping easily because of lack of finishing pressure during finishing nonferromagnetic materials, a new method of increasing the finishing pressure by using the “pressure-increasing bag” in the finishing system is put forward. A lot of comparative experiments on finishing nonferromagnetic materials with the “pressure-increasing bag” and without the “pressure-increasing bag” are performed. Under the same experimental conditions, the amount of diameter-reduction d is increased from 1μm to 1.88μm and the surface roughness is improved from Ra0.315μm to Ra0.250μm by using the “pressure-increasing bag”. The results show that the finishing pressure is increased obviously and the MAF efficiency of finishing nonferromagnetic materials is improved dramatically by using the “pressure-increasing bag”.

Effects of Provocation on Emotions and Aggression: An Experimental Study with Aggressive Children

2006 ◽  
Vol 65 (2) ◽  
pp. 117-124 ◽  
Author(s):  
Christina Stadler ◽  
Sonja Rohrmann ◽  
Sibylle Steuber ◽  
Fritz Poustka
Keyword(s):  
Experimental Study ◽  
Positive Emotions ◽  
Skin Conductance Level ◽  
Physiological Measures ◽  
Competitive Reaction ◽  
Experimental Conditions ◽  
Conduct Disordered ◽  
Physiological Variables ◽  
Aggressive Children ◽  
Conductance Level

In this study, the effects of an experimental-induced provocation on emotions and aggression were examined in 34 aggressive conduct-disordered children using a competitive reaction time paradigm. Two experimental conditions were created, an increasing provocation and a low constant provocation condition. Self-rated anger was assessed directly after provocation on a 5-point-visual scale. In addition, negative and positive emotions as well as physiological measures (heart rate and skin conductance level) were measured at baseline and after provocation. Results revealed that participants’ aggressive behaviour and subjective emotions differed as a function of the opponent’s level of provocation. Concerning physiological parameters, no significant differences were found between the experimental conditions. These results suggest that affective, but not physiological variables characterize reactive aggression in conduct-disordered children.

Effect of combined citicoline and glutamate antibodies on acute, generalized convusions induced by pentylenetetrazole in mice

2018 ◽  
pp. 24-29
Author(s):  
М.Н. Карпова ◽  
Л.В. Кузнецова ◽  
Н.Ю. Клишина ◽  
Л.А. Ветрилэ
Keyword(s):  
Drug Combination ◽  
Subcutaneous Injection ◽  
Seizure Activity ◽  
Experimental Conditions ◽  
Slow Progression ◽  
Experiment Control ◽  
Effective Doses ◽  
Experimental Justification ◽  
Series Of Experiments ◽  
The Brain

Цель исследования. На 2 моделях острых генерализованных судорог (ОГС), вызванных конвульсантом пентилентетразолом (ПТЗ), изучить эффективность сочетанного применения ноотропа цитиколина - препарата с противосудорожным действием, нейрорегенеративной, нейропротекторной активностью и антител (АТ) к глутамату, обладающих противосудорожной активностью. Методика. Эксперименты выполнены на мышах-самцах линии C57Bl/6 (n = 87) массой 22-28 г. Эффективность сочетанного применения цитиколина и АТ к глутамату изучали на двух моделях ОГС. Выполнено 2 серии экспериментов. В 1-й серии ОГС вызывали внутривенным введением 1% раствора ПТЗ со скоростью 0,01 мл/с. Для изучения эффективности сочетанного применения препаратов определяли минимальное противосудорожное действие цитиколина (Цераксон, «Nicomed Ferrer Internaсional, S.A.») и АТ к глутамату при их внутрибрюшинном введении. С этой целью цитиколин вводили в дозах 500 и 300 мг/кг за 1 ч до введения ПТЗ, АТ к глутамату - в дозах 5 и 2,5 мг/кг за 1 ч 30 мин до введения ПТЗ. АТ к глутамату получали путем гипериммунизации кроликов соответствующим конъюгированным антигеном. Во 2-й серии ОГС вызывали подкожным введением ПТЗ в дозе 85 мг/кг. Для изучения эффективности сочетанного действия изучаемых препаратов последние вводили в минимально действующих дозах, установленных в 1-й серии экспериментов. Контролем во всех сериях опытов служили животные, которым вводили в аналогичных условиях и в том же объеме физиологический раствор. Результаты. Показано, что сочетанное применение цитиколина и АТ к глутамату в минимально действующих дозах (300 и 2,5 мг/кг соответственно) при моделировании ОГС не вызывало повышения судорожной активности мозга и усиления противосудорожных свойств препаратов. Заключение. Cочетанное применение цитиколина и АТ к глутамату в минимально действующих дозах не вызывало повышения судорожной активности мозга, что свидетельствует о безопасности совместного применения препаратов. Проведенное исследование может служить также экспериментальным обоснованием возможности использования сочетанного применения данных препаратов при судорогах с целью замедления прогрессирования нейродегенеративных процессов и благоприятного влияния на когнитивные функции. Aim. To study the effectivity of a combination of citicoline, a nootropic substance with neuroregenerative, neuroprotective, and anticonvulsant actions, and glutamate antibodies (АB) with an anticonvulsant action in two models of acute generalized convulsions (AGC) caused by the convulsant pentylenetetrazole (PTZ). Methods. Experiments were conducted on C57Bl/6 mice (n = 87) weighing 22-28 g. Effects of combined citicoline and glutamate АB were studied on two models of AGС. In the first series of experiments, AGС was induced by intravenous infusion of a 1% PTZ solution at 0.01 ml/sec. In the second series, AGС was induced by a subcutaneous injection of PTZ 85 mg/kg. To evaluate efficacy of the drug combination minimum intraperitoneal anticonvulsant doses of citicoline (Tserakson, Nicomed Ferrer Internacional, S.A.) and glutamate АB were determined. To this purpose, citicoline was administered at 500 and 300 mg/kg 1 h prior to PTZ, and glutamate АB was administered at 5 and 2.5 mg/kg 90 min prior to PTZ. Glutamate АB was obtained by hyperimmunization of rabbits with a respective conjugated antigen. In the second series of experiments, AGС was induced by a subcutaneous injection of PTZ 85 mg/kg. To evaluate the effect of the drug combination, the drugs were administered at the minimum effective doses determined in the first series of experiment. Control animals were injected with the same volume of saline in the same experimental conditions. Results. The combination of citicoline and glutamate AB used at minimum effective doses of 300 and 2.5 mg/kg, respectively, did not increase the seizure activity in the brain and enhanced anticonvulsant properties of the drugs in two models of AGС. Conclusion. The combination of citicoline and glutamate AT at minimum effective doses did not increase the convulsive activity in the brain, which supported safety of the drug combination. Besides, this study can serve as an experimental justification for using the drug combination in convulsions to favorably influence cognitive functions and slow progression of neurodegenerative processes.

EXPERIMENTAL STUDY OF REACTION OF ETHANOL WITH OXYGEN BEHIND SHOCK WAVES USING ATOMIC RESONANCE ABSORPTION SPECTROSCOPY METHOD

2020 ◽  
Author(s):  
N. S. Bystrov ◽  
◽  
A. V. Emelianov ◽  
A. V. Eremin ◽  
P. I. Yatsenko ◽  
...  
Keyword(s):  
Experimental Study ◽  
Shock Waves ◽  
Absorption Spectroscopy ◽  
Vacuum Ultraviolet ◽  
Resonance Absorption ◽  
Atomic Resonance ◽  
Quantitative Measurements ◽  
Series Of Experiments ◽  
Kinetics Of Reaction ◽  
Oxygen Atoms

The kinetics of reaction of C2H5OH with N2O behind shock waves is studied. The quantitative measurements of the time profiles of concentration of O atoms were carried out by the method of atomic resonance absorption spectroscopy (ARAS) using resonance vacuum-ultraviolet line of O-atom at 130.5 nm. For the calibration of absorption intensity of oxygen atoms depending on its concentration, the special series of experiments in the mixture containing different amounts of N2O in Ar was carried out at T = 2100 ± 50 K when molecule of N2O is completely dissociated. An experimental study of the appearance and consumption of oxygen atoms during the reaction of ethanol with oxygen in mixture 10 ppm N2O + (10 ... 0.1) ppm C2H5OH + Ar at temperatures of 16002300 K and pressures of 200-300 kPa have been carried out. A kinetic analysis of obtained data was performed using the Chemkin package.

Development of embryonic rat eyes in organ culture

Development ◽  
1968 ◽  
Vol 19 (3) ◽  
pp. 407-414
Author(s):  
R. Christy Armstrong ◽  
Joel J. Elias
Keyword(s):  
Organ Culture ◽  
Culture Medium ◽  
Folic Acid Deficiency ◽  
Experimental Conditions ◽  
Acid Deficiency ◽  
Series Of Experiments ◽  
Development In Vitro ◽  
Ocular System

Abnormalities of the ocular system which appear in organ culture in Waymouth's medium with freshly added glutamine (Armstrong & Elias, 1968) resemble those caused by transitory pteryolglutamic acid (PGA or folic acid) deficiency in vivo (Armstrong & Monie, 1966). The configurations of such malformations as lens herniations, retinal diverticula, and rosette-like formations of the retina are remarkably similar in both cases. The experiments reported in this paper were undertaken in an effort to understand the mechanisms involved in the production of similar abnormalities by two very different experimental conditions: the addition of glutamine in vitro and the transitory deficiency of PGA in vivo. One series of experiments involved the effects of manipulation of the PGA and glutamine content of the culture medium on eye development in vitro. Parallel studies on PGA-deficiency in vivo were undertaken in conjunction with organ-culture experiments in order to compare the effects on abnormal eye morphogenesis.

Use of a Pendulum for Passive Structural Vibrations Control: An Experimental Study

1993 ◽  
Author(s):  
A. Ertas ◽  
O. Cuvalci
Keyword(s):  
Experimental Study ◽  
Dynamic Response ◽  
Passive Control ◽  
Control Device ◽  
Structural Vibrations ◽  
Pendulum System ◽  
Series Of Experiments ◽  
Tip Mass

Abstract The dynamic response of a beam-tip mass-pendulum system subjected to sinusoidal excitations is considered. The conditions under which resonant and nonresonant oscillations occur are investigated and discussed. The main objective of this study was to conduct a series of experiments to investigate the autoparametric interaction between the first two modes of the system. The use of a pendulum as a passive control device was experimentally evaluated.

Sonometric Evaluation of Eustachian Tube Function Using Broadband Stimuli

1980 ◽  
Vol 89 (3_suppl) ◽  
pp. 178-184 ◽  
Author(s):  
Krishna G. Murti ◽  
Erdem I. Cantekin ◽  
Richard M. Stern ◽  
Charles D. Bluestone
Keyword(s):  
Eustachian Tube ◽  
A Priori ◽  
Broadband Noise ◽  
Ear Canal ◽  
Experimental Conditions ◽  
Diagnostic Significance ◽  
Tube Function ◽  
Series Of Experiments ◽  
Sound Conduction ◽  
Clinical Instrument

New measurements of acoustical transmission through the eustachian tube (ET) have been obtained in a series of experiments directed toward the development of a clinical instrument to assess ET function behind an intact tympanic membrane (TM). Using a sound conduction method, a sound source was placed in one nostril, and the acoustical energy that was transmitted through the ET was measured by a microphone placed in the ear canal. The present study used a broadband noise as the acoustical stimulus, in contrast to the tonal stimuli employed in previous investigations. This stimulus was chosen because it is believed to reduce the variability in the data due to intersubject differences in the acoustics of the nasopharynx and ET, and to avoid any a priori assumptions concerning the specific frequencies that would be of greatest diagnostic significance. Averaged spectra of the sound transmitted to the ear canal were obtained for three experimental conditions: acoustical source present during subject swallowing, source present with no swallowing, and subject swallowing with source absent. A Bayesian classification scheme based on the statistics of these spectra was used in classifying subjects into one of two possible categories, normal and abnormal ET function. A comparison was made between sonometric classification and classification based on a tympanometric ET function test. Correlation between the two methods was 87.1%.

Experimental estimation of the head loss coefficient at surcharged four-way junction manholes

2018 ◽  
Vol 15 (8) ◽  
pp. 780-789 ◽  
Author(s):  
Jun Beom Jo ◽  
Jung Soo Kim ◽  
Sei Eui Yoon
Keyword(s):  
Head Loss ◽  
Loss Coefficient ◽  
Experimental Estimation ◽  
Head Loss Coefficient

Experimental study of debris head loss through a pressurized water reactor recirculation sump screen after LOCA

2011 ◽  
Vol 241 (7) ◽  
pp. 2462-2469 ◽  
Author(s):  
Byung Gi Park ◽  
Jong Woon Park ◽  
Chang Hyun Kim
Keyword(s):  
Experimental Study ◽  
Head Loss ◽  
Pressurized Water Reactor ◽  
Pressurized Water ◽  
Water Reactor

Head loss coefficient of orifice plate energy dissipator

2011 ◽  
Vol 49 (6) ◽  
pp. 830-831 ◽  
Author(s):  
Umberto Fratino ◽  
Alessandro Pagano
Keyword(s):  
Head Loss ◽  
Loss Coefficient ◽  
Orifice Plate ◽  
Energy Dissipator ◽  
Head Loss Coefficient
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