The article deals with axial-symmetric subsonic air-to air ejector with a diffuser adapted for boundary layer suction. The diffuser, which is placed after the mixing chamber of the ejector, has a high divergence angle and is therefore inefficient. To increase efficiency, the diffuser is equipped with a slot enabling boundary layer suction. The effect of boundary layer suction on the airflow in the ejector was measured, as were the static pressure distribution on the mixing chamber wall and ejector characteristics. Both diffuser and ejector efficiency were calculated. Although the efficiency of the diffuser was increased, the efficiency of the ejector itself remained low. and Obsahuje seznam literatury
The requirements of conservators who take care of historical monuments are that the materials for rehabilitation of old renders should have a composition as similar to the historical materials as possible and should provide improvement in durability. Fine and coarse sepiolite and synthetic zeolite pellets were chosen as additives in the development of lime mortars for conservation work, due to their unique adsorption properties providing water to the mortar system and acting as water reservoirs in conditions of low humidity. Flexural and compressive strength and the dynamic modulus of elasticity were studied at 28, 90 and 180 days of curing. Addition of both fine and coarse sepiolite and zeolite pellets caused improvement of mechanical strength of mortars, clearly evident at later ages of curing. Elasticity modulus ranged from 2.3 GPa to 3.6 GPa relating to a high deformation capability of mortars and confirming their suitability for use in conservation work., Slávka Andrejkovičová, Eduardo Ferraz, Ana L. Velosa, António S. Silva and Fernando Rocha., and Obsahuje bibliografii
The study investigates differences between three most widely used methods in voice training and therapy: Phonation into a resonance tube with the outer end in the air or submerged 2-10 cm in water (‘water resistance therapy‘ with bubbling effect), and phonation into a very thin straw. One female speech trainer served as subejct. Acoustic and electroglottographic (EGG) signals, and both mean and dynamic air pressures in the mouth cavity were registered for repetitions of [pu:pu], and for phonation into the tubes, while the outer end was randomly shuttered in order to get an estimate of subglottic pressure. Soft and normal phonations were recorded. Phonation threshold decreased with tube in air, suggesting that increased input reactance assists small amplitude oscillation of the vocal folds. Oral pressure (Poral) increased with increasing impedance offered by the tube and straw, most when the tube was 10 cm in water. In most cases subglottic pressure (Psub) increased relatively more than Poral, so that tranglottic pressure (Ptrans) was higher in the exercises compared to vowel. Contact quotient (CQ) from EGG increased, which may be due to increased Ptrans. In tube 10 cm in water Ptrans decreased and CQ increased suggesting increased adduction as compensation. Exercises that increase oral eir-pressure offer a possibility to train flottal and respiratory adjustments under the influence of increased flow resistance which may prevent excessively strong vocal fold collisions. and Obsahuje seznam literatury
The contribution aims to provide material that can be used in development of more realistic physical as well as theoretical models of voice production. The experimental set-up methodology and the results of measurement of airflow rate, subglottal, oral and generated acoustic air pressures are presented together with the simultaneously measured flow-induced vibrations of a vocal folds replica, made of soft silicon rubber, and recorded by a high speed camera. The data were measured during ‘soft‘ phonation onset, given by the phonation threshold airflow rate, and during ‘normal‘ phonation for the airflow rate of about three times higher. A model
of the human vocal tract in the position for production of vowel [u:] was used, and the flow resistance was raised by phonating into a glass resonance tube either in the air or having the other end of the tube submerged under water, and by phonating into a narrow straws. The results for the pressures presented in time and frequency domain are comparable with the physiological ranges and limits measured in humans for ordinary phonation and for production of vocal exercises used in voice therapy. and Obsahuje seznam literatury
The aircraft engine lubricating oil monitoring is essential in terms of the flight safety and also for reduction of the maintenance cost. The concentration of metal elements in the lubricating oil includes a large amount of information about the health condition of the aircraft engine. By monitoring the lubricating oil, maintenance engineers can judge the performance deterioration of the aircraft engine and can find the latent mechanical faults in the aircraft engine in advance. But it is difficult for traditional methods to predict the tendency of the mental elements concentration in the lubricating oil. In this paper, a time series prediction method based on process neural network (PNN) is proposed to solve this problem. The inputs and the connection weights of the PNN are time-varied functions. A corresponding learning algorithm is developed. To simplify the learning algorithm, a set of appropriate orthogonal basis functions are introduced to expand the input functions and the connection weight functions of the PNN. The effectiveness of the proposed method is proved by the Mackey-Glass time series prediction. Finally, the proposed method is utilized to predict the Fe concentration in the aircraft engine lubricating oil monitoring, and the test results indicate that the proposed model seems to perform well and appears suitable for using as a predictive maintenance tool.
Chronic airflow limitation, caused by chronic obstructive pulmonary disease (COPD) or by asthma, is believed to change the shape and the position of the diaphragm due to an increase in lung volume. We have made a comparison of magnetic resonance imaging (MRI) of diaphragm in supine position with pulmonary functions, respiratory muscle function and exercise tolerance. We have studied the differences between patients with COPD, patients with asthma, and healthy subjects. Most interestingly we found the lung hyperinflation leads to the changes in diaphragmatic excursions during the breathing cycle, seen in the differences between the maxim al expiratory diaphragm position (DPex) in patients with COPD and control group (p=0.0016) . The magnitude of the diaphragmatic dysfunction was significantly related to the airflow limitation expressed by the ratio of forced expiratory volume in 1 s to slow vital capacity (FEV 1 /SVC) , (%, p=0.0007); to the lung hyperinflation expressed as the ratio of the residual volume to total lung capacity (RV/TLC), (%, p=0.0018) and the extent of tidal volume constrain expressed as maximal tidal volume (V Tmax ), ([l], p=0 .0002); and the ratio of tidal volume to slow vital capacity (VT/SVC), (p=0.0038) during submaximal exercise. These results suggest that diaphragmatic movement fails to contribute sufficiently to the change in lung volume in emphysema. Tests of respiratory muscle function were related to the position of the diaphragm in deep expiration, e.g. neuromuscular coupling (P 0.1 /VT) (p=0.0232). The results have shown that the lung volumes determine the position of the diaphragm and function of the respiratory muscles. Chronic airflow limitation seems to change the position of the diaphragm, which thereafter influences inspiratory muscle function and exercise tolerance. There is an apparent relationship between the position of the diaphragm and the pulmonary functions and exercise tolerance., L. Hellebrandová, J. Chlumský, P. Vostatek, D. Novák, Z. Rýznarová, V. Bunc., and Obsahuje bibliografii
The paper presents a minimal extension of classical logic. The extension covers, mainly, (i) an introduction of legal regulations conceived as specific elements of provisions in legal rules; and (ii) an introduction of the application operation on legal regulations. Such an operation transforms a legal regulation into an empirical proposition describing some desired state of affairs. Moreover, it is assumed that legal arguments may contain two kinds of premises: a) legal regulations; and b) statements of empirical fact as a legal reality. A typical case of b) includes statements expressing the application or non-application of legal regulation in certain circumstances. Due to the distinctions introduced, the extended system of classical logic makes possible to analyse the logical structure of perfect norms as pentatomic. Although such a system is far remote from sophisticated systems of deontic logics, it is almost completely sufficient for lawyers’ practice., Článek prezentuje minimální rozšíření klasické logiky. Rozšíření se týká zejména (i) zavedení právních předpisů koncipovaných jako zvláštní prvky ustanovení právních předpisů; a (ii) zavedení provozu aplikaceo právních předpisech. Taková operace proměňuje právní úpravu v empirický návrh, který popisuje určitý požadovaný stav. Dále se předpokládá, že právní argumenty mohou obsahovat dva druhy prostor: a) právní předpisy; a b) vyjádření empirické skutečnosti jako právní skutečnosti. Typickým případem b) jsou prohlášení vyjadřující aplikaci nebo neuplatnění právní úpravy za určitých okolností. Díky zavedeným rozdílům umožňuje rozšířený systém klasické logiky analyzovat logickou strukturu dokonalých norem jako pentatomickou. Ačkoli takový systém je daleko od sofistikovaných systémů deontické logiky, pro praxi právníků je téměř zcela dostačující., and František Gahér
Jaké jsou pracovní podmínky vědců a vědkyň na českých vysokých školách a výzkumných institucích? S čím jsou čeští vědci a vědkyně nejvíce nespokojeni? Co jim brání v kariérním růstu? Jak se dělá věda ve chvíli, kdy se stanete rodičem?, Nina Fárová, Kateřina Cidlinská, Marcela Linková, Hana Maříková, Hana Tenglerová., and Obsahuje bibliografické odkazy
The conference organized under the auspices of the Minister of Foreign Affairs of the Czech Republic Lubomír Zaorálek, was held on the 13-14th April 2016. It aimed at addresing the issues of overcoming global threats, developing inter-cultural and intra-cultural dialogue, including inter-religious and intra-religious respect and discussions, enhancing justice, mutual cooperation and stability. The conference was attended by Czech and foreign experts in social sciences and humanities, ambassadors of EU countries and Muslim states as well journalists. The theme of global threats requires an analysis and ideas for finding solutions to various cultural, social, political, religious, military and other conflicts. and Marina Hužvárová.