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9062. Size analysis of solid particles using laser diffraction and sieve analysis
- Creator:
- Hrnčířová, Michaela, Pospíšil, Jiří, and Špiláček, Michal
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- solid particles, size distribution, laser diffraction, and sieve analysis
- Language:
- English
- Description:
- The article compares two methods of determination of the particle size distribution of fine ash. The respective methods compared are the sieve analysis and laser difraction. The former is one of the oldest methods in use, applicable to size separation of large grain size particles. The latter is a modern advanced method that employs lase diffraction to determine the size distribution. For the measurement itself, the sieve analyser Analysette 3 PRO and the universal laser diffraction device Analysette 22 MicroTec plus, both from the Fritsch company, were applied. The comparison was made by analysing fine ash particles from biomass burners. The particles were in the size range of 0.08 μm to 2000 μm. and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
9063. Skew inverse power series rings over a ring with projective socle
- Creator:
- Paykan, Kamal
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- mathematics, flat socle ring, skew inverse power series ring, skew polynomial ring, annihilator, projective socle ring, 13, and 51
- Language:
- English
- Description:
- A ring R is called a right PS-ring if its socle, Soc(RR), is projective. Nicholson and Watters have shown that if R is a right PS-ring, then so are the polynomial ring R[x] and power series ring R[[x]]. In this paper, it is proved that, under suitable conditions, if R has a (flat) projective socle, then so does the skew inverse power series ring R[[x−1; alfa, delta]] and the skew polynomial ring R[x; alfa, delta], where R is an associative ring equipped with an automorphism and an alfa-derivation delta. Our results extend and unify many existing results. Examples to illustrate and delimit the theory are provided., Kamal Paykan., and Seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
9064. Školní fase: prameny pro dějiny výchovy a vzdělávání v 18. století
- Creator:
- Kbelík, Michal
- Format:
- print, text, regular print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- vzdělávání, školství, osvícenství, education, enlightenment, školní zprávy, school reports, 8, and 94(437)
- Language:
- Czech and English
- Description:
- The article deals with school reports on gains and properties of schools and their masters (the so called "fassiones" in Latin). It focuses on the part of archive of Bohemian Gubernium containing school reports from 1775 to 1792. Previous Czech historians as Josef Hanzal or Jan Šafránek examined these reports especially with the use of quantitative methods, but the goal of this study is to show that more points of view are possible and available. More details about the problems of schools and teachers, content of school instruction, and employed books and tables could also be found in this kind of source., Michal Kneblík., and Obsahuje bibliografické odkazy
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
9065. Skrývá před námi foton ještě něco zásadního?
- Creator:
- Novotný, Jan
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fyzika, fotony, physics, photons, 6, and 53
- Language:
- Czech and English
- Description:
- Student fyziky si rychle zvykne na to, že rychlost světla a mezní rychlost (šíření interakcí a informace) jsou téměř synonyma - foton jako světelné kvantum se pohybuje mezní rychlostí a musí tedy mít nulovou (klidovou) hmotnost. (Poznamenejme, že v částicové fyzice vítězí v posledních desetiletích tendence jinou než klidovou hmotnost nezavádět.) Více než 50 let starý Bassův a Schrödingerův článek dokumentovaný v tomto čísle Československého časopisu pro fyziku by se proto mohl jevit jako okrajová kuriozita. Podrobnější seznámení s literaturou (výstižné shrnutí dějin fotonu a problémů s ním spojených viz [1]) ukazuje, že tomu tak zdaleka není., We give a brief overview of history and perspectives of theoretical investigations concerning the possibility of the non-zero rest mass of photon., Jan Novotný., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
9066. Slant and Legendre curves in Bianchi-Cartan-Vranceanu geometry
- Creator:
- Călin, Constantin and Crasmareanu, Mircea
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Bianchi-Cartan-Vranceanu metric, slant curve, Legendre curve, Lancret invariant, and helix
- Language:
- English
- Description:
- We study Legendre and slant curves for Bianchi-Cartan-Vranceanu metrics. These curves are characterized through the scalar product between the normal at the curve and the vertical vector field and in the helix case they have a proper (non-harmonic) mean curvature vector field. The general expression of the curvature and torsion of these curves and the associated Lancret invariant (for the slant case) are computed as well as the corresponding variant for some particular cases. The slant (particularly Legendre) curves which are helices are completely determined.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
9067. Slant and pseudo-slant submanifolds in ${\rm LCS}$-manifolds
- Creator:
- Atçeken, Mehmet and Kumar Hui, Shyamal
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- slant submanifold, pseudo-slant submanifold, and ${\rm LCS}$-manifold
- Language:
- English
- Description:
- We show new results on when a pseudo-slant submanifold is a LCS-manifold. Necessary and sufficient conditions for a submanifold to be pseudo-slant are given. We obtain necessary and sufficient conditions for the integrability of distributions which are involved in the definition of the pseudo-slant submanifold. We characterize the pseudo-slant product and give necessary and sufficient conditions for a pseudo-slant submanifold to be the pseudo-slant product. Also we give an example of a slant submanifold in an LCS-manifold to illustrate the subject.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
9068. Sleep apnoea in patients with nocturnal hypertension: a multicenter study in the Czech Republic
- Creator:
- Milada Hobzová, Karel Šonka, Vítězslav Kolek, Placková, M, Jitka Zapletalová, Radvanský, M, Eva Kriegová, Jan Václavík, and Martin Pretl
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fyziologie člověka, human physiology, Sleep apnoea, Nocturnal hypertension, Ambulatory blood pressure monitoring, Mallampati score, Epworth sleepiness scale, BMI, 14, and 612
- Language:
- English
- Description:
- Sleep apnoea (SA) is common in patients with hypertension. Nowadays, limited data on the prevalence of SA in nocturnal hypertension (NH) exist. Therefore, we studied the occurrence of SA in Czech patients and its association with 24-h ambulatory blood pressure monitoring (ABPM), breathing disturbances in sleep, anthropometric data, Mallampati score and Epworth sleepiness scale (ESS) using the Apnea Link device. Undiagnosed SA was found in 72.9 % patients (29.3 % mild, 26.6 % moderate, 17.0 % severe) of 188 patients with NH measured by ABPM. The median of the apnoea-hypopnoea index (AHI) was 12.0 (25th-75th percentile 5.0-23.8). Moderate/severe SA (AHI≥15) was associated with BMI, waist circumference, mean night saturation (SpO2), t90, oxygen desaturation index (ODI), ESS (daytime BP only) (p≤0.032), but not ABPM parameters and Mallampati score (p>0.09). A likelihood of moderate/severe SA was enhanced by ODI>14.5 events/h (odds ratio=57.49, 95 % CI=22.79-145.01), t90>6.5 % (8.07, 4.09-15.92), mean night SpO2<93.5 % (3.55, 1.92-6.59), BMI>29.05 kg/m2 (6.22, 3.10-12.49), circum waist>105.5 cm (3.73, 1.57-8.83), but not by any ABPM parameter. In conclusion, a high incidence of SA (72.9 %) was observed in Czech patients with NH. SA severity was associated with body characteristics and oxygenation parameters, but not with ABMP parameters and Mallampati score., M. Hobzová, K. Šonka, M. Pretl, J. Václavík, E. Kriegová, M. Radvanský, J. Zapletalová, M. Placková, V. Kolek., and Seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
9069. Sliding mode differentiator via improved adaptive notch filter
- Creator:
- Wang, Juan, Zhang, Hehong, Yu, Yuanlong, Dan, Zhihong, Xiao, Gaoxi, Gu, Qiuming, and Zhai, Chao
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- sliding mode differentiator, parameter tuning scheme, adaptive notch filter, and altitude ground test facility
- Language:
- English
- Description:
- To tackle the difficulty in tuning the parameters of sliding mode differentiator (SMD), an improved adaptive notch filter based real-time parameter tuning scheme (denoted as ANF-SMD) is presented. Specifically, the integral feedback of the system output errors is introduced in constructing the cost function for the adaptive notch filter so as to estimate the real-time amplitude and frequency of given inputs. Then, upon the deterministic formula between the parameters of the SMD and the input signals, the parameters of the SMD can be adjusted adaptively as inputs vary. Simulation results show that the proposed ANF-SMD scheme performs well in signal filtering and differentiation estimation. The effectiveness of the proposed ANF-SMD is further experimentally verified on the pressure signal processing for the altitude ground test facility.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
9070. Sliding subspace design based on linear matrix inequalities
- Creator:
- Tapia, Alán, Márquez, Raymundo, Bernal, Miguel, and Cortez, Joaquín
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- sliding mode control, variable structure, sliding subspace design, and linear matrix inequalities
- Language:
- English
- Description:
- In this work, an alternative for sliding surface design based on linear and bilinear matrix inequalities is proposed. The methodology applies for reduced and integral sliding mode control, both continuous- and discrete-time; it takes advantage of the Finsler's lemma to provide a greater degree of freedom than existing approaches for sliding subspace design. The sliding surfaces thus constructed are systematically found via convex optimization techniques, which are efficiently implemented in commercially available software. Examples are provided to illustrate the effectiveness of the proposed approach.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public