Wyniki wyszukiwania - Biblioteka Nauki

1

Performance testing of an adaptive information exchange system in discributed control systems

100%

Strzelczyk P.

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2017

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tom z. 75

93--95

EN

This article presents results of performance tests for a developed information exchange system dedicated to distributed control systems.

2

Leading edge skewed-swept diagonal compressor rotor and numerical analysis on its internal flow mechanism

100%

Zhou B. , You B. , Wu W. , Wu K.-Q.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2009

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tom Vol. 13, No 1-2

33-43

EN

The structure of each part of a diagonal compressor directly affects its overall performance and internal flow. We introduce the Reynolds-averaged Navier-Stokes flow simulation for unit calculation on the whole system including a diagonal impeller, a vaneless diffuser and a volute. By analyzing different flow chromatograms of specific sections, we can compare the configuration of three types of diffusers and volutes and the meridian flow status of the corresponding diagonal compressors which serves as a basis for the impeller flow path as well as for its matching designs. Considering the interference between the rotor and the upstream and downstream stillness body, this thesis analyzes how the vaneless diffuser meridian flow path, the volute flow path and its section secondary flow affect the upstream rotor flow. Both the calculation and experimental data on the rotor outlet are compared, as well as the calculated numerical value of the meridian plane streamline distribution and the diffuser velocity distribution, upstream and downstream, coincides with the designed numerical value. Without changing the conventional quasi-three-dimensional design system, the thesis applies the annulus wall boundary layer theory and the velocity distribution diagram to sweep and skew the leading edge of the airfoil. A performance test shows that the leading edge skewed-swept diagonal rotor can better improve the stall characteristic in a low flow rate area and expand the surge margin, compared with conventional diagonal rotor. It can also efficiently restrain the low-momentum fluid conglomeration near the wall region and reduce the secondary flow loss by sweeping and skewing the blade properly. The purpose of the thesis is to make a contribution to optimizing the overall structure design of diagonal compressors and to study further the complex internal flow between the leading edge skewed-swept diagonal rotor and the cover.

3

Development of a Committee of Artificial Neural Networks for the Performance Testing of Compressors for Thermal Machines in Very Reduced Times

100%

Coral R. , Flesch C. A. , Penz C. A. , Borges M. R.

Metrology and Measurement Systems

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2015

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tom Vol. 22, nr 1

79--88

EN

This paper presents a new test method able to infer - in periods of less than 7 seconds - the refrigeration capacity of a compressor used in thermal machines, which represents a time reduction of approximately 99.95% related to the standardized traditional methods. The method was developed aiming at its application on compressor manufacture lines and on 100% of the units produced. Artificial neural networks (ANNs) were used to establish a model able to infer the refrigeration capacity based on the data collected directly on the production line. The proposed method does not make use of refrigeration systems and also does not require using the compressor oil.

4

Experimental verification of the steering performance of all-hydraulic crawler chassis

88%

Lv X. , Shi X. , Lv X. , Wang T.

Engineering Transactions

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2018

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tom Vol. 66, iss. 4

427--442

EN

The force conditions in the steering system of the chassis under different conditions are analyzed theoretically for the independently designed and developed all-hydraulic crawler chassis. Using the multi-body dynamic simulation software RecurDyn, the chassis steering performance on sandy loam and clay pavements, and the steering performance under different steering radiuses on the sandy loam pavement are simulated and analysed dynamically respectively. The steering resistance moment is studied when the pavement conditions and steering radius are different. This research selects inside and outside crawler slip ratio as an index, and road conditions, speed and steering radius as factors to test the steering performance of all-hydraulic crawler chassis under different operating conditions. It is observed from the simulation results that during the pivot steering on the sandy loam, the drive torque and braking torque of the driving wheel are larger than on the clay ground. With the decrease of the steering radius, the torques of the left and right driving wheel are both gradually increasing. In the same steering radius, the torque of the outside driving wheel is larger than that of the inside driving wheel. The simulation results are consistent with the theoretical analysis results. In the steering performance test, the factors influencing the slippage rate on both sides of the crawler are such that the influence of the steering radius is greater than that pf the pavement condition and the pavement condition influence is greater than that of the speed. Among them, the steering radius has a significant influence on the slip ratio of the inside crawler, and an extremely significant influence on the slip ratio of the outside crawler. This research can provide a certain theoretical basis and technical reference for the development of hydraulic crawler chassis and optimization of the steering system.

5

Performance test of network devices

88%

Bolanowski M. , Paszkiewicz A.

|

tom Vol. 13, no. 1

29--36

EN

Selection of components in contemporary computer networks is extremely important, not only because of the project budget but also because of the network performance. Therefore, it is necessary to perform tests before deploying devices. In this paper the authors show that the performance of test network devices is dependent on the nature of network traffic including its statistical properties. Also a new hybrid model of the system for testing the network device based on the q-additivity of traffic flows was proposed.

6

Discharge measurement and performance tests of hydraulic units in low-head small hydropower installations

75%

Steller J. , Adamkowski A. , Henke A. , Janicki W. , Kaniecki M. , Krzemianowski Z.

|

2015

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tom nr 130

3--29

EN

In course of over half a century the test teams of the Szewalski Institute of Fluid-Flow Machinery (IMP PAN) have conducted numerous performance tests of small hydropower (SHP) installations on various occasions and motivations, including updating or establishing performance characteristics of old machines, acceptance of new units, checking or optimising the cam correlation of new or refurbished double-regulated turbines, checking performance of prototype turbines under field conditions. The discharge measurement techniques have included currentmeter, pressure-time and acoustic methods. Index tests, using the Winter-Kennedy and other differential pressure methods, as well as current-meter and acoustic techniques, have been employed quite frequently to optimise the cam curves of double-regulated machines. In one case a simplified technique based solely on the power/wicket gate opening relationship was checked. This paper discusses some techniques applied when determining the absolute efficiency and optimizing cam correlations by means of absolute and index test methods. Cubic spline formulae as applied to integrate the flow velocity field in a hydrometric section are derived. Results of a discharge measurement by means of the current-meter and pressure-time method are compared as a special case study. Finally, practical recommendations addressed both to the power plant owners and the test team members are formulated.

7

The impact of value of daily gains of body weight on meat content of pigs of different breeds

75%

Michalska G. , Nowachowicz J. , Chojnacki Z. , Wasilewski P. D. , Bucek T.

|

nr 2

77-83

8

Genetic parameters of some traits of stallions evaluated for performance by training centres during 1977-2000

75%

Geringer de Oedenberg H. , Dobrowolski M. , Zaton-Dobrowolska M. , Wierzbicki H.

Electronic Journal of Polish Agricultural Universities. Series Animal Husbandry

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2004

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tom 07

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nr 2

EN

Studies on genetic parameters that describe performance traits of stallions managed in Training Centres are of great importance, since they allow breeders to rationally design their breeding programmes. The outcomes of such studies also include breeding methods that are adequate for an improvement of traits which are of different heritability or which have different coefficients of correlation between them. As an effect of evaluated stallions will be significant over the decades to follow, the studies we have performed are important in terms of both theory and practice. The study covered performance test records of 2825 stallions tested in Training Centres in 1977-2000. Heritability estimates for the selected traits evaluated during performance tests were estimated with the REML method. The recorded values ranged from 0.09, for the pulse rate, to an exceptionally high record for dressage, as judged by foreign riders, reaching 0.95.

9

75%

Sobczynska M. , Kownacki M.

Journal of Applied Genetics

|

1995

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tom 36

|

nr 1

EN

A comparison was made of a correlated response to selection between populations of mice selected for body weight at weaning on the basis of their own performance or their progeny. Selection was conducted throughout 15 generations and during the last two generations, three replicas were crossed within each group. A correlated response to selection of the body weight on day 42, weight gains between day 21 and 42 and litter size at birth was significantly higher in the group of mice evaluated on the basis of their progeny. A negative correlated response occurred in the litter size at birth in the group evaluated on the basis of animals' own performance. The realized genetic correlations in the group evaluated on the basis of animals' own performance was 0.9, 0.1 and 0.8, respectively, between the body weight on day 21 and 42, body weight on day 21 and weight gains between day 21 and 42, body weight on day 21 and litter size at birth.

10

The effect of selection for traits of low heritability conducted in noninbred populations on the basis of progeny or performance tests

75%

Sobczynska M. , Kownacki M.

Journal of Applied Genetics

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1995

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tom 36

|

nr 2

EN

The investigations were carried out to compare selection conducted on the basis of progeny with that on the basis of animals'own performance. Selection was conducted for the body weight at weaning (at the age of 21 days), which is a trait of low heritability (h²=0.1). It was run throughout 15 generations, whereas in generations 13 and 14 three experimental replicas were crossed to obtain population free of inbreeding. A cumulated response to selection was higher in the group selected on the basis of animals' own performance, but after crossing the replicas it decreased clearly in the both groups. The cumulated selection differential was higher in the group selected on the basis of animals' own performance. However, a statistical analysis of the obtained results showed no significant difference between the two selection methods.

11

Performance test results of young crossbred boars with Zlotnicka Spotted and Pietrain breeding

63%

Michalska G. , Chojnacki Z.

Annals of Animal Science. Supplement

|

2005

|

nr 1

12

Efektywność sprężarkowej pompy ciepła powietrze-woda po modernizacji układu kierowniczego dolnego źródła ciepła

63%

Knaga J.

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tom R. 13, nr 6

141-147

PL

W pracy przedstawiono wyniki badań eksploatacyjnych małej sprężarkowej pompy ciepła OW 150 typu powietrze-woda, przeznaczonej do przygotowania ciepłej wody użytkowej, po przeprowadzonej modernizacji układu kierowniczego na dolnym źródle ciepła. Przeprowadzona szczegółowa analiza wyników badań pokazała, iż współczynnik efektywności energetycznej zmienia się w granicach 1,45-3,45 (przy wartości przeciętnej 2,05) w czasie cyklu nagrzewania wody w zasobniku. Ponadto badania prowadzone w warunkach eksploatacyjnych po modernizacji układu kierowniczego dolnego źródła ciepła, wskazują na istotny wzrost efektywności energetycznej o 11% w odniesieniu do badań wstępnych.

EN

The paper presents results of performance tests carried out for small compressor heat pump (OW 150), air-water type, designed for preparing hot utility water, after completed modernisation of guiding system in lower heat source. Detailed analysis of test results has proven that during water heating cycle in water tank the energy efficiency coefficient value ranges from 1.45 to 3.45 (mean value is 2.05). Moreover, tests performed in service conditions after modernisation of lower heat source guiding system indicate significant increase in energy efficiency by 11%, compared to preliminary tests.

13

Entropy analysis of performance test results of warmblood stallions

63%

Dobek A. , Borowska A. , Molinski K. , Szwaczkowski T.

Journal of Animal and Feed Sciences

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2012

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tom 21

|

nr 1

EN

The objective of the present study was to evaluate relationships among recorded traits in a 100-day stationary performance test in warmblood stallions in Poland. The possibility of reducing the number of recorded traits was assessed as well. The data are from 582 warmblood stallions undergoing a 100-day test in 2002-2010 at two Polish training centres. The stallions were pre-selected on nine single conformation and movement traits and then inspected on nineteen performance traits scored by the head of the training centre, judging commission, and test riders. To establish the relationships within the data, entropy analysis was used. Entropy and conditional entropy in relation to the final assessment, as well as joint entropy, mutual information, and their quotient were estimated. High relationships between traits depend on their source of variability (head of training centre, judging commission, test rider). Variability over time of ranks for many traits is influenced by the differences in the genetic structure of the stallions tested in the last ten years. These estimates of conditional entropy can be helpful in derivation of weights for the recorded conformation, movement, and performance traits.

14

Performance testing of cast agricultural tools operating in soil

63%

Pirowski Z. , Kranc M. , Olszynski J. , Gwizdz A. , Goscianski M.

Teka Komisji Motoryzacji i Energetyki Rolnictwa

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2012

|

tom 12

|

nr 2

15

Performance tests of an airlift pump equipped with a perforated rubber diaphragm mixer

63%

Kalenik M. , Malarski M.

|

nr 1

EN

The paper presents an analysis of the tests of an airlift pump that has pumped water Qw or a mixture of water with sand Qw + Qs . The research included a determination of performance and efficiency characteristics for an airlift pump with internal diameter of the discharge pipeline d = 0.04 m equipped with a PM 50 air mixer with perforated rubber diaphragm. The tests were carried out for three lifting heights of water and a mixture of water and sand H: 0.40, 0.80, 1.20 m, with a fixed length of the discharge pipeline submergence h = 0.80 m. It was found that water flow rate Qw and the mixture of water Qw with sand Qs flow rate increased with the growth of the airflow rate Qp, reaching maximum and then decreasing. Whereas with the rise of lifting height of water or the mixture of water with sand H, the water Qw and the mixture of water Qw with sand Qs flow rate decreased. It has been shown that the airflow rate in this type of installation during the discharge of the water cannot be less than 5,0 m³ · h⁻¹ and should not exceed 16,0 m³ · h⁻¹. When the mixture of water with sand is discharged, airflow also cannot be less than 9.80 m³ · h⁻¹ and should not exceed 17.0 m³ · h⁻¹. The airlift pump efficiency η decreased with a rise of mixture of water with sand lifting height.

PL

W artykule przedstawiono analizę wyników badań laboratoryjnych powietrznego podnośnika, który tłoczył wodę z wydajnością Qw lub mieszaninę wody i piasku Qw + Qs . Zakres badań obejmował wyznaczenie charakterystyk wydajności isprawności pracy powietrznego podnośnika o średnicy wewnętrznej rurociągu tłocznego d = 0,04 m, wyposażonego w mieszacz typu PM 50 z perforowaną gumową membraną. Badania wykonano dla trzech wysokości podnoszenia wody oraz mieszaniny wody i piasku H: 0,40, 0,80, 1,20 m, przy stałej długość zanurzenia rurociągu tłocznego h = 0,80 m. Stwierdzono, że natężenie przepływu wody Qw oraz mieszaniny wody Qw i piasku Qs rosło wraz ze wzrostem natężenia przepływu powietrza Qp, osiągając maksimum, a następnie malało. Natomiast wraz ze wzrostem wysokości podnoszenia wody lub mieszaniny wody i piasku H, natężenie przepływu wody Qw, jak również mieszaniny wody Qw i piasku Qs malało. Wykazano, że natężenie przepływu powietrza w tego typu urządzeniu podczas tłoczenia wody nie może być mniejsze niż 5,0 m³ · h⁻¹ i nie powinno przekraczać 16,0 m³ · h⁻¹. Podczas tłoczenia mieszaniny wody Qw i piasku Qs również nie może być mniejsze niż 9,80 m³ · h⁻¹ i nie powinno przekraczać 17,0 m³ · h⁻¹. Sprawność η badanego powietrznego podnośnika malała wraz ze wzrostem wysokości podnoszenia mieszaniny wody i piasku.

16

Photovoltaic power plant inspection and diagnostic

63%

Vrana M. , Moravek J. , Mastny P.

Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska

|

2015

|

tom nr 3

55--58

EN

This paper presents methods of photovoltaic panel inspection in the field. The aim is to verify value of on-site tests. The basic parameters for comparing the quality of photovoltaic panels are indicated by the manufacturer’s datasheet. Diagnostic in the field commonly uses a combination of different analyzers and infrared cameras. The paper compares the evaluation of the parameters at different climatic conditions by special photovoltaic analyzer, conventional analyzer with recalculation according the IEC standards and flash tester. The comparison of different methods and analyzers has been performed with the practical experience from the measurements. Further, the standards for the inspection of photovoltaic panels and best practices for their implementation are described.

PL

W artykule przedstawiono metody kontroli panelu fotowoltaicznego w miejscu montażu. Celem jest sprawdzenie wartości testów na on-site. Podstawowe parametry służące do porównywania jakości paneli słonecznych są wskazywane przez producenta w arkuszu produktu. Do diagnostyki na miejscu powszechnie używa się kombinacji różnych analizatorów oraz kamer termowizyjnych. W artykule dokonano porównania oceny parametrów w różnych warunkach klimatycznych przez specjalny analizator fotowoltaiczny, zwykły analizator z przeliczaniem zgodnie z normami IEC i flash-tester. Porównanie różnych metod i analizatorów została wykonana na podstawie praktycznych doświadczeń z pomiarów. Ponadto, opisane są standardy kontroli paneli fotowoltaicznych, a także najlepsze praktyki w ich realizacji.

17

Relationships between performance test results of young crossbred boars with Zlotnicka Spotted and Pietrain breeding

63%

Michalska G. , Nowachowicz J. , Bucek T. , Wasilewski P. D.

Annals of Animal Science. Supplement

|

2005

|

nr 1

18

Load-Elongation Characteristics of Connecting and Shock-Absorbing Components of Personal Fall Arrest Systems

51%

Baszczyński K. , Jachowicz M.

Fibres & Textiles in Eastern Europe

|

2012

|

tom Vol. 20, no. 6A (95)

78--85

EN

The process of arresting a fall from a height by protective equipment is characterised by two most important values: the arrest force and the distance over which the fall arrest occurs. The time course of these values is determined primarily by the mechanical parameters of the connecting and shock-absorbing components of the fall arrest system, such as textile energy absorbers, retractable type fall arresters and guided type fall arresters. The paper presents the methods of testing used up till now to determine the properties of connecting and shock-absorbing components. Their disadvantages are demonstrated and a new method allowing to determine the load-elongation characteristics of connecting and shockabsorbing components containing textile elements is described. The method presented and test stand are based on simultaneous measurements of the force acting in the object investigated and its elongation. For measurements of elongation under dynamic conditions, an extensometer equipped with a high speed camera was used. The results of tests performed under static and dynamic conditions on objects made of fibre rope and webbing used in equipment protecting against falls from a height are presented. The results obtained demonstrate significant differences between these characteristics, which confirms the effect of the loading velocity on the mechanical parameters of textile elements used as parts of personal fall arrest systems. Therefore data allowing to develop numerical models of connecting and shock-absorbing components were obtained.

PL

W artykule przedstawiono metody badania stosowane dotychczas w celu określenia właściwości ochronnych elementów łączących i amortyzujących. Wykazano ich wady i zaprezentowano nową metodę pozwalającą na wyznaczanie charakterystyk siła - wydłużenie elementów zawierających struktury włókiennicze. Zaprezentowana metoda i stanowisko badawcze opiera się na równoczesnym pomiarze siły działającej w badanym obiekcie oraz jego wydłużenia. Dla potrzeb pomiaru wydłużeń w warunkach dynamicznych zastosowano ekstensometr z kamerą do szybkich zdjęć. Przedstawiono wyniki badań, prowadzonych w warunkach statycznych i dynamicznych, obiektów wykonanych z lin i taśm włókienniczych stosowanych do produkcji sprzętu chroniącego przed upadkiem z wysokości. Uzyskane wyniki wykazały istotne różnice między tymi charakterystykami. Potwierdziło to wpływ prędkości obciążania na parametry mechaniczne włókienniczych elementów sprzętu chroniącego przed upadkiem z wysokości. Dzięki temu uzyskano dane pozwalające na opracowanie modeli numerycznych elementów łącząco-amortyzujących.

19

Effect of Mechanical Factors on the Protective Parameters of Textile Elements in Personal Equipment Protecting Against Falls from a Height

51%

Baszczynski K. , Jachowicz M.

Fibres & Textiles in Eastern Europe

|

2011

|

tom Vol. 19, no. 5 (88)

117--124

EN

Assurance of consistent protective parameters throughout the whole period of use is one of the more important problems associated with personal equipment containing textile elements that protects against falls from a height. The most important factors causing mechanical damage to such equipment are indicated in the paper, which also presents the methods and test stands used for conducting tests involving the application of loads to the equipment under static and dynamic conditions with simultaneous exposure to additional mechanical factors. Such factors comprised friction against steel and concrete elements of specially devised shapes, simulating the effect of the worksite edge during a fall arrest. The results obtained demonstrated that an additional factor such as friction against an obstacle significantly decreases the mechanical strength, creating unfavorable conditions for a fall arrest. Thus, it can be concluded that if personal protective equipment protecting against falls from a height is to be used under conditions including potential exposure to additional mechanical factors, it must be characterised by special protective properties.

PL

Jednym z najważniejszych problemów związanych z indywidualnym sprzętem chroniącym przed upadkiem z wysokości jest zapewnienie zachowania parametrów ochronnych jego elementów włókienniczych podczas całego okresu użytkowania. W artykule dokonano analizy tych czynników oraz wskazano na najważniejsze, które mogą mieć istotne znaczenie z punktu widzenia bezpieczeństwa użytkownika sprzętu. Przedstawiono metody i stanowiska badawcze, które wykorzystano do badania zachowania sprzętu ochronnego, w warunkach obciążenia statycznego i dynamicznego, podczas oddziaływania na niego dodatkowych czynników mechanicznych. Jako główny czynnik mechaniczny przyjęto tarcie o profile stalowe i betonowe, o założonych wymiarach, symulujące brzeg stanowiska pracy. Uzyskane wyniki badań w warunkach statycznych i dynamicznych pokazują, że dodatkowy czynnik w postaci tarcia o elementy konstrukcyjne stanowiska pracy znacząco obniża parametry wytrzymałościowe sprzętu oraz pogarsza, z punktu widzenia człowieka, warunki procesu powstrzymywania spadania z wysokości. Wynika z tego, że jeżeli indywidualny sprzęt ochronny ma być stosowany na stanowiskach pracy, gdzie jego elementy włókiennicze będą narażone na kontakt z niebezpiecznymi obiektami podczas powstrzymywania spadania, to musi on charakteryzować się dodatkowymi parametrami ochronnymi.

20

Modeling the Performance of Horizontal Anchor Lines during Fall Arrest

51%

Baszczyński K.

Fibres & Textiles in Eastern Europe

|

2017

|

tom Vol. 25, no. 5 (125)

95--103

EN

The basic materials used for the construction of anchor lines for personal equipment protection against falls from a height are ropes and textile webbing. During fall arrest, horizontal anchor lines significantly affect the forces acting on the worker and the work site elements, as well as the fall arrest distance. Manufacturers of the equipment are required to estimate those parameters for various conditions of use by numerical simulations with a validated model. The model discussed in this paper reflects the mechanical structure of the line (whether singles-span or multi-span) taking into account Maxwell’s and Kelvin-Voigt’s non-linear rheological models for viscoelastic materials. The model consists of a system of seven non-linear differential equations with the parameters describing static load-elongation characteristics and time-courses of dynamic loading forces for selected ropes and textile webbing. The numerical model developed was used to simulate the performance of horizontal anchor lines of different constructions. The model was validated by comparing the numerical calculations with laboratory test results and was shown to be sufficiently accurate to be used for designing fall protection equipment.

PL

Podstawowymi materiałami stosowanymi do produkcji poziomych lin kotwiczących dla indywidualnego sprzętu chroniącego przed upadkiem z wysokości są liny i tkane taśmy włókiennicze. Poziome liny kotwiczące wpływają w istotny sposób na przebieg sił działających na człowieka podczas powstrzymywania jego spadania, drogę na jakiej to zachodzi oraz przebieg sił działających na konstrukcję stanowiska pracy. Z tego względu producent sprzętu ochronnego musi szacować te wielkości dla różnych warunków użytkowania np. stosując symulację numeryczną wykorzystującą zweryfikowany model. Model przedstawiony w artykule opiera się na zależnościach mechanicznych opisujących konstrukcję poziomej liny oraz nieliniowych modelach reologicznych obiektów lepko sprężystych Maxwella i Kelvina-Voigta. Strukturę modelu opisano układem nieliniowych równań różniczkowych z parametrami wynikającymi z charakterystyk statycznych siła obciążająca – wydłużenie oraz czasowych przebiegów siły obciążającej wybrane liny i tkane taśmy włókiennicze. Model został użyty do symulacji zachowania różnych wariantów konstrukcyjnych poziomych lin kotwiczących. Porównanie zasymulowanych numerycznie odpowiedzi modelu z wynikami badań laboratoryjnych wykazało zadowalającą jego dokładność, a co za tym idzie możliwość wykorzystania do projektowania sprzętu ochronnego.