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Number of results: 40
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Abstract

Monoculture of modern cereal crops are popular due to the technical and organizationa lreasons. They are easier in crop husbandry, qua lity and product use. However, in monoculture chemical protection of crops is a norm, due to the fact that they are more susceptible to diseases, pests and sometimes weed infestation. In order to keep high and stable grain yields and quality in monoculture one has to use high inputs. Experimentally and practically it has been proved that cultivar and species mixtures can constitute an alternative to cultivar growing in pure stands. It has been found that in mixtures opperate different epidemiological and ecological factors, which lead to considerable disease reduction, pest and weed control, which finally result in higher and more stable grain yields than in barley varietes grown in pure stands. The results of two years field experiment designed to evaluate epidemiological and economical effects of winter barley cultivar mixtures are presented. The studies were carried out in two sites – experimental lStation for Variety Testing Słupia Wielka (in Wielkopolska region) and Plant Breeding Station Bąków (Opole District). This two sites were 300 km away from each other, and had different soi land meteorological conditions. In the experiment impact of different barley cultivars and their different two- and three-component mixtures were tested with reduced dosages of fungicidies on grain yield in the mixtures compared with pure stands were evaluated.

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Authors and Affiliations

Anna Tratwal
Jadwiga Nadziak
Magdalena Jakubowska
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Abstract

Spring triticale 'Migo', and spring barley 'Maresi' grown in pure stand and in their mixtures were used in field experiment. Disease occurrence, number of culms and heads as well as yield were assessed. Powdery mildew and scald of barley and Septaria leaf blotch of triticale occurred in lower degree in mixtures than in pure stands, but only in the years with weather conditions favourable for the diseases development. Fusarium stem rot and eyespot of both plant species as well as net blotch of barley occurred in similar degree in all treatments or even in some mixtures in higher degree than in pure stands.
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Authors and Affiliations

Tadeusz Michalski
Zbigniew Weber
Barbara Gołębniak
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Abstract

In 1997-1999 observations of health status of spring barley grown in two-component mixtures with cereals or pea were performed in two experiments, differing in the agricultural utility of soil. A much better health status of the studied species was found in the mixed crop than in their pure stand. Two-component mixtures were differentiated in the occurrence of leaf diseases caused by Drechslera teres, Drechslera graminea, Puccinia graminis and P. hordei, Rhynchosporium secalis and Erysiphe graminis. The healthiness of lower parts of stem and roots depended on the quality of soil and mixtures factor. A higher infection due to foot root rot complex was noted on barley cultivated on the poorer soil in homogenous stand.
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Authors and Affiliations

Anna Wenda-Piesik
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Abstract

In the four-year experiment the impact of four different barley varieties and selected two-and three-component mixtures were tested. The studies were carried out at two sites: Experimental Station for Variety Testing Słupia Wlk. (Wielkopolska region) and Plant Breeding Station Bąków (Opole District) during four growing seasons (2001/2002–2004/2005). The aim of the studies was to evaluate the yield through growing barley variety mixtures in combination with reduced use of fungicide and application dose rates. Positive effects (1–15% yield increase in mixtures compared to pure stands) were observed. On the base of obtained results it can be stated that winter barley variety mixtures can constitute an alternative way of growing winter barley, especially at low-input and ecological agriculture.

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Authors and Affiliations

Anna Tratwal
John Law
Haidee Philpott
Andy Horwell
Jane Garner
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Abstract

Distillation boundaries originate from saddle azeotropes, dividing the composition space into distillation regions. In heterogeneous mixtures distilled in packed columns, distillation regions overlap. The common area of distillation regions is parametrically sensitive, and it determines the possibilities of crossing (at a finite reflux) the distillation boundaries defined for a total reflux or reboil ratio. This work is an extended research of the paper (Królikowski et al., 2011) conducted to scrutinize whether the distillation regions overlapped in heteroazeotropic systems distilled in staged columns. Presented studies were performed by finding such composition points of the products, for which the rectifying profiles of staged columns were ended in different distillation regions. Calculations were executed for the heterogeneous mixture classified under Serafimov's topological class as 3.1-2: ethanol - benzene - water. Distillation regions for staged columns were found to overlap each other in the heterogeneous systems. As a result, their common part was parametrically sensitive.

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Authors and Affiliations

Andrzej Królikowski
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Abstract

This article discusses results of an analysis of mechanical properties of a sintered material obtained from a mixture of elemental iron, copper and nickel powders ball milled for 60 hours. The powder consolidation was performed by hot pressing in a graphite mould. The hot pressing was carried out for 3 minutes at 900 °C and under a pressure of 35 MPa. The sintered specimens were tested for density, porosity, hardness and tensile strength. Their microstructures and fracture surfaces were also examined using a scanning electron microscope (SEM). The study was conducted in order to determine the suitability of the sintered material for the manufacture of metal-bonded diamond tools. It was important to assess the effects of chemical composition and microstructure of the sintered material on its mechanical properties, which were compared with those of conventional metal bond material produced from a hot-pressed SMS grade cobalt powder. Although the studied material shows slightly lower strength and ductility as compared with cobalt, its hardness and offset yield strength are sufficiently high to meet the criteria for less demanding applications.

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Authors and Affiliations

J. Lachowski
J.M. Borowiecka-Jamrozek
J. Konstanty
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Abstract

The study of the different engineering materials according to their mechanical and dynamic characteristics has become an area of research interest in recent years. Several studies have verified that the mechanical properties of the material are directly affected by the distribution and size of the particles that compose it. Such is the case of asphalt mixtures. For this reason, different digital tools have been developed in order to be able to detect the structural components of the elements in a precise, clear and efficient manner. In this work, a segmentation model is developed for different types of dense-graded asphalt mixtures with grain sizes from 9.5 mm to 0.0075 mm, using sieve size reconstruction of the laboratory production curve. The laboratory curve is used to validate the particles detection model that uses morphological operations for elements separation. All this with the objective of developing a versatile tool for the analysis and study of pavement structures in a non-destructive test. The results show that the model presented in this work is able to segment elements with an area greater than 0.0324 mm2 and reproduce the sieve size curves of the mixtures with a high percentage of precision.

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Authors and Affiliations

O.J. Reyes-Ortiz
M. Mejía
J.S. Useche-Castelblanco
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Abstract

The paper presents results of a study concerning ammonium and nitratc(V) fixation by soil irrigated with municipal wastcwatcrs ( 1 - 60 mm and 2 doses - 120 mm) and estimation or the possibility or using organic soil and grass-mixture for the wastewater treatment. It was found that the studied soil and the plant applied showed a very high capacity or binding ammonium ions (up to 96%), and lower in the case ofnitrates(V) (up to 71 %). It was also demonstrated that the single irrigation dose was better utilized compared to the double dose.
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Authors and Affiliations

Urszula Kotowska
Teresa Włodarczyk
Barbara Witkowska-Walczak
Cezary Sławiński
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Abstract

Biological diversity within a mixture field allows for better use of habitat and agro-technical conditions by the mixtures, which can be seen by higher and more stable yields than varieties sown separately. Our studies were conducted in the growing seasons 2011/2012–2014/2015 as field experiments with four winter barley varieties (Bombaj, Gil, Gregor, Bażant) and three, two- and three-component mixtures (Bombaj/Gil, Bombaj/Gregor, Gil/Gregor/Bażant). Seven different chemical treatments with fungicides were applied. The aim of this study was to compare the different varieties of winter barley with their mixtures for resistance to powdery mildew infection. To achieve this aim the logistic model for the analysis of data was used. Of the varieties under consideration, the best and the most resistant variety was Gregor, while the weakest and the most susceptible to diseases (powdery mildew) was Gil. This variety was also significantly weaker than any of the other mixtures taken into account. Moreover, it was so weak that when it was included in mixtures with other varieties, it weakened these mixtures as well.

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Authors and Affiliations

Ewa Bakinowska
Anna Tratwal
ORCID: ORCID
Kamila Nowosad
Jan Bocianowski
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Abstract

Twenty-eight two-, three-, four-, and five-component amine mixtures have been evaluated as possible activators of CO2 absorption into aqueous carbonate/bicarbonate solutions. Measurements were per- formed using a pressure autoclave with a sparger at conditions close to industrial ones. On the basis of these results, a formula for a new, more efficient amine activator named INS13 was developed. The activator was tested both in a pilot plant and on an industrial scale in an ammonia plant producing 300 tons/day of ammonia. Activator INS13 was applied in a number of ammonia plants in Poland and abroad.

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Authors and Affiliations

Grzegorz Bińczak
Ryszard Pohorecki
Władysław Moniuk
Cezary Możeński
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Abstract

Increasing environmental pressure against waste disposal, particularly fine waste surface storage and concern about mining damages have resulted in an increase in the popularity of a fly ash, tailing and binding agent mixture used as compaction grout of roof fall rocks in a gob area of longwalls. Backfilling of voids forming as a result of exploitation with the fall of roof with mixtures containing fine-grained industrial wastes is a common practice in coal mines. It is aimed at achieving numerous technological and ecological advantages as well as at controlling mining hazards. Research on hydraulic transport of fine-grained slurry conducted to date focused mainly on issues related to the analysis of the conditions related to pipeline transportation. The processes concerning the propagation of mixtures within the gob, on the other hand, remain largely unknown. The process of flow of fine-grained slurry through the caving is subject to a series of factors related, among other things, with the properties of the applied wastes and mixtures, the characteristics of the gob as well as the variability of these properties during the flow through the gob and in time. Due to the lack of sufficient knowledge pertaining to the changes taking place in the gob and in the slurry while it penetrates the gobs, no methods allowing for the design and optimization of the gob grouting process have been established so far. The paper presents the selected results of laboratory tests regarding the flow of ash and water mixtures in a model of a gob, pertaining to two selected types of fly ash produced in hard coal combustion, particularly concerning the impact of the type of the ash and the density of the slurry on the effectiveness of the gob grouting process.

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Authors and Affiliations

Marcin Krzysztof Popczyk
Rafał Jendruś
ORCID: ORCID
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Abstract

Many modern processes for the production and casting of metals and their alloys are carried out in protective gas atmospheres, which protect them, for example, from oxygen pollution. This applies, for example, to titanium, magnesium or aluminum alloys. Most liquid alloys are comprised of constituents that differ in vapor pressures, resulting in harmful phenomenon during melting due to evaporation of some of its components. This harmful process may be limited by the selection of a suitable gas atmosphere in which the liquid metal treatment process is carried out. In the paper, results of study on the impact of the type of gas atmosphere on the rate of evaporation of zinc in argon – hydrogen mixtures are presented. It should be noted that such mixtures are used, for example, in metal welding processes, in which it is also possible to evaporate a component of the so-called liquid metal pool. The research results showed that the rate of zinc evaporation increases with the increase of hydrogen content in the gas atmosphere.
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Authors and Affiliations

T. Matuła
1
ORCID: ORCID

  1. Silesian University of Technology, Faculty of Materials Engineering, 8 Krasińskiego Str., 40-019 Katowice, Poland
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Abstract

In the four-year experiment the impact of four different winter barley varieties and selected two- and three-component mixtures were tested. Reduced dosages of fungicides on disease reduction in the mixtures compared with pure stands were evaluated. The studies were carried out at two sites: Experimental Station for Variety Testing Słupia Wlk. (Wielkopolska region) and Plant Breeding Station Bąków (Opole District). Observations on powdery mildew occurrence during the vegetation season were done every 7–10 days. In order to compare the disease occurrence levels on different cultivars in pure stands and on their mixtures combined with different fungicide treatments the Area Under Disease Progress Curve (AUDPC) was evaluated. On the base of the AUDPC values the reduction of powdery mildew occurring in the mixtures due to epidemiological and ecological factors functioning in mixed stands were also evaluated. On the base of obtained results it can be stated that winter barley variety mixtures combined with different fungicide treatments do reduce the powdery mildew incidence comparing to pure stands and winter barley variety mixtures can constitute an alternative way of growing winter barley, especially at low-input and ecological agriculture.

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Authors and Affiliations

Anna Tratwal
John Law
Haidee Philpott
Andy Horwell
Jane Garner
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Abstract

For the reason of environmental problems connected with the use of furan binders, attention is increasingly being paid to self-setting mixtures using alkali resols. A resol binder stabilized with KOH, NaOH is hardened by liquid esters with the formation of alkaline salts. The increase of their concentration affects the shortening of the mixture bench life, it also decreases strength, increases abrasive wear to moulds and cores, and results in uneconomical dilution of the reclaim with expensive new base sand. The length of life (bench life) of mixtures plays an important role in the manufacture of huge and voluminous moulds and cores in self-setting mixtures. This study aims at analyzing the function of reactive alkaline salts in the reclaim, monitors the consequences of its thermal exposure on the properties of selfsetting mixtures, and deals with development of methods evaluating its qualities.

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Authors and Affiliations

P. Jelínek
J. Beňo
J. Duda
F. Mikšovský
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Abstract

In order to understand commands given through voice by an operator, user or any human, a robot needs to focus on a single source, to acquire a clear speech sample and to recognize it. A two-step approach to the deconvolution of speech and sound mixtures in the time-domain is proposed. At first, we apply a deconvolution procedure, constrained in the sense, that the de-mixing matrix has fixed diagonal values without non-zero delay parameters. We derive an adaptive rule for the modification of the de-convolution matrix. Hence, the individual outputs extracted in the first step are eventually still self-convolved. This corruption we try to eliminate by a de-correlation process independently for every individual output channel.

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Authors and Affiliations

F.A. Okazaki
W. Kasprzak
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Abstract

This study deals with the behavior of composite blends constituted of rigid and impervious grainsincluded in saturated clay paste of kaolin, considered as permeable and deformable. Permeabilitytests performed during standard oedometr tests (before each load step) highlight the key role ofthe original and actual state of the clay paste, and show the existence of a threshold of sandgrain concentration above which a structuring effect influences its permeability. In the light ofthese experiments some usual homogenization methods (with simplifying assumptions to make theproblem manageable) are considered in order to model the mixture permeability. Qualitative andquantitative comparisons with experimental data point out their respective domain of interest andlimitations of such approaches.

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Authors and Affiliations

G. Kacprzak
C. Boutin
T. Doanh
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Abstract

The exploitation and processing of lignite in the Bełchatów region is connected with the formation of various mineral waste materials: varied in origin, mineral and chemical composition and raw material properties of the accompanying minerals, ashes and slags from lignite combustion and reagipsum from wet flue gas desulphurisation installations. This paper presents the results of laboratory tests whose main purpose was to obtain data referring to the potential use of fly ashes generated in the Bełchatów Power Plant and selected accompanying minerals exploited in the Bełchatów Mine in the form of self-solidification mixtures. The beidellite clays were considered as the most predisposed for use from the accompanying minerals , due to pozzolanic and sorption properties and swelling capacity. Despite the expected beneficial effects of clay minerals from the smectite group on the self-settling process as well as the stability of such blends after solidification, the results of physical-mechanical tests (compressive strength and water repellence) were unsatisfactory. It was necessary to use Ca (OH)2, obtained from the lacustrine chalk as an activator of the self-settling process It was necessary to use lacustrine chalk as an activator of the self-solidification process. The presence of calcium will allow the formation of cement phases which will be able to strongly bond the skeletal grains. Also, the addition of reagipsum to the composition of the mixture would contribute to the improvement of the physico-mechanical parameters. The elevated SO4 2– ion in the mixture during the solidification allows for the crystallization of the sulphate phases in the pore space to form bridges between the ash and clay minerals. The use of mixtures in land reclamation unfavourably transformed by opencast mining in the Bełchatów region would result in measurable ecological and economic benefits and would largely solve the problem of waste disposal from the from the operation and processing of lignite energy.

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Authors and Affiliations

Elżbieta Hycnar
Marek Waldemar Jończyk
Tadeusz Ratajczak
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Abstract

Fly-ash is a form of production waste produced as a result of the burning of coal for energy production. Millions of tonnes of this waste are produced worldwide every year; hence it is extremely important to dispose of it in a useful way, including through treating the initial raw material to obtain a material of higher quality. The aim of the present work is to determine the suitability of processed fly-ash from lignite for reinforcing (stabilizing) soils used in the building of road foundations and embankments. The results provide a method of recycling this waste while at the same time obtaining new materials and technologies for use in road building. This is an important issue both environmentally and in terms of the positive effect that processed fly-ash can have on the stability of road structures.

This article presents the results of experiments carried out using fly-ash produced from lignite at the P¹tnów Power Plant. This ash was first modified (activated) using a Wapeco magnetic activator, and then used to produce hydraulic binders (with the addition of cement) and soil-binder mixtures. These mixtures were made using natural soils from seven different deposits in the Lubuskie region (western Poland). They were stabilized using two hydraulic binders (strength ratings 3 MPa and 9 MPa) added in different amounts (6% and 8% relative to the mass of the soil). During the experiment, a determination was made of the increase in the strength of the analysed samples (after 14, 28, and 42 days) and the increase in the bearing ratio (immediately after consolidation and after 7 days).

Interpretation of the results of the experiment made it possible to assess the dynamics of the increase in compression strength and load-bearing capacity of various soils stabilized with hydraulic binders produced from lignite ash, and to indicate possibilities for the use of these materials.

The analysis showed that it is possible to use these binders for the stabilisation of soils, enabling soils formerly considered to have weak load-bearing capacity (clayey sand; clayey, sandy gravel; clays) to be classified as fully usable in road construction.

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Authors and Affiliations

Urszula Kołodziejczyk
Michał Ćwiąkała
Aleksander Widuch
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Abstract

In agriculture, the mixing of pesticides in tanks is a common practice. However, it is necessary to previse possible physical-chemical implications of this practice, which may affect the efficiency of the treatments performed. Therefore, the objective of this study was to evaluate the effects of the addition of acaricide to insecticidal spray mixtures on the formation of spray droplets and the interaction with citrus leaves. The experimental design was totally randomized, in a (2 × 3 + 1) factorial scheme for seven treatments. Factor A corresponded to the spray mixture used (isolate or in the mixture). Factor B corresponded to the insecticides tested (lambda-cyhalothrin + thiamethoxam, phosmet, and imidacloprid) and the control consisted of a spray mixture with spirodiclofen only. Nine replications were performed for characterization of the spray droplet size spectrum and four replications for the analysis of the surface tension and the contact angle. The mixture of pesticides showed positive results in terms of application safety. The addition of acaricide to insecticide spray mixtures reduced the surface tension and contact angle of droplets on the adaxial surface of orange leaves. There was an increment in volume median diameter (VMD), a significant reduction in the volume of droplets with drift-sensitive size and improvement in the uniformity of droplet size. Therefore, the addition of acaricide to an insecticide spray mixture positively influenced spray droplet formation and the interaction with citrus leaves providing better coverage and droplet size fractions with an appropriate size for safe and efficient application.

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Authors and Affiliations

Jaqueline Franciosi Della Vechia
Renata Thaysa Santos
Fabiano Griesang
Cícero Mariano Santos
Marcelo Costa Ferreira
Daniel Junior Andrade
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Abstract

In years 1998-2000 the pot experiment was carried out. The aim of this investigation was to determine the influence of brown coal, waste activated sludge, their mixtures and farmyard manure on the content of Cr and Ni in soil material and in the dry mass of Lolium multiflorum Krato variety. The pots were filled with loamy sand as soil material, brown coal which had low energetic value from Sieniawa and Konin mines. waste activated sludges were taken from mechanical-biological sewage purification plants located at Siedlce, Luków and Drosed (poultry processing plant) and mixed farmyard manure. In each year of experiment four cuts were harvested. The total content of Cr and Ni in soil materials and in dry mass of grass after dry combustion of samples was determinate by !CP-AES method on spectrometer Optima 3200 RL manufactured by Perkins-Elmer. The highest content of Cr and Ni was determinate in soil materials from objects fertilized with waste activated sludge from Siedlce. The average content of Cr in dry mass of grass reached 5.15 mg/kg and Ni 3.05 mg/kg.
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Authors and Affiliations

Stanisław Kalembasa
Barbara Symanowicz
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Abstract

The purposes of this study were to investigate the impact of proportions of cast iron scrap, steel scrap, carbon and ferro silicon on hardness and the quality of cast iron and to obtain an appropriate proportion of the four components in iron casting process using a mixture experimental design, analysis of variance and response surface methodology coupled with desirability function. Monte Carlo simulation was used to demonstrate the impacts of different proportions of the four components by varying the proportions of components within ±5% of the four components. Microstructures of the cast iron sample obtained from a company and the cast iron samples casted with the appropriate proportions of the four components were examined to see the differences of size and spacing of pearlite particle. The results showed that linear mixture components were statistically significant implying a high proportion of total variability for hardness of the cast iron samples explained by the casting mixtures of raw materials. The graphite of the sample casted from the appropriate proportion has shorter length and more uniform distribution than that from the company. When varying percentages of the four components within ±5% of the appropriate proportion, simulated hardness values were in the range of 237 to 256 HB.
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Authors and Affiliations

C. Saikaew
1
ORCID: ORCID
S. Harnsopa
1

  1. Department of Industrial Engineering, Khon Kaen University, Khon Kaen 40002 Thailand
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Abstract

The quality of the castings depends, among other influences, on the quality of the moulding mixture used. The silica sands used are characterized by high thermal expansion compared to other sands. The tendency to dilatation of the moulding mixture can be influenced by the choice of the granulometric composition of the basic sand and the grain size. The aim of this work is to present the influence of grain distribution of foundry silica sand BG 21 from Biala Góra (Poland) and the degree of sorting (unsorted, monofraction, polyfraction) on the degree of thermal dilatation of the sand and thus on the resulting quality of the casting and susceptibility to foundry defects. For the purpose of measuring thermal dilatation, clay wash analysis was performed, sieve analysis of the sand was carried out, and individual sand fractions were carefully sorted. The measurements confirmed a higher thermal expansion in the case of monofractional sand grading, up to 51.8 %. Therefore, a higher risk of foundry stress-strain defects, such as veining, can be assumed.
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Bibliography

[1] Czerwinski, F. (2017). Modern aspects of liquid metal engineering. Metallurgical and Materials Transactions B. 48(1), 367-393. DOI: 10.1007/s11663-016-0807-6.
[2] Brůna, M. & Galčík, M. (2021). Casting quality improvement by gating system optimization. Archives of Foundry Engineering. 21(1), 132-136. https://doi.org/10.24425/afe.2021.136089.
[3] Monroe, R. (2005). Porosity in castings. AFS Transactions. 113, 519-546.
[4] Kowalski, J.S. (2010). Thermal aspects of temperature transformation in silica sand. Archives of Foundry Engineering. 10(3), 111-114. ISSN (1897-3310).
[5] Jelínek, P. (2004). Binder systems of foundry moulding mixtures – chemistry of foundry binders. (1st ed.). Ostrava. ISBN: 80-239-2188-6. (in Czech).
[6] Svidró, J., Svidró J. T., & Diószegi, A. (2020). The role of purity level in foundry silica sand on its thermal properties. Journal of Physics: Conference Series. 1527(1), 012039, 1-8. DOI 10.1088/1742-6596/1527/1/012039.
[7] Chao, Ch. & Lu, H. (2002). Stress-induced β→ α-cristobalite phase transformation in (Na2O+Al2O3)-codoped silica. Materials Science and Engineering: A. 328(1-2), 267-276. DOI: 10.1016/S0921-5093(01)01703-8.
[8] Hrubovčáková, M., Vasková, I., Benková, M. & Conev, M. (2016). Opening material as the possibility of elimination veining in foundries. Archives of Foundry Engineering. 16(3), 157-161. DOI: 10.1515/afe-2016-0070.
[9] Beňo, J., Adamusová, K., Merta, V., Bajer, T. (2019). Influence of silica sand on surface casting quality. Archives of Foundry Engineering. 19(2), 5-8. DOI: 10.24425/afe.2019.127107.
[10] Thiel, J., Ziegler, M., Dziekonski, P., Joyce, S. (2007). Investigation into the technical limitations of silica sand due to thermal expansion. Transactions of the American Foundry Society. 115, 383-400.

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Authors and Affiliations

M. Bašistová
1
ORCID: ORCID
P. Lichý
1
ORCID: ORCID

  1. VSB-Technical University of Ostrava, Faculty of Materials Science and Technology, Department of Metallurgical Technologies, Czech Republic
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Abstract

This paper presents a method of optical fluorescence analysis for the evaluation of homogeneity of multicomponent grain mixtures. This method is based on the evaluation of the content of fluorescent marker. Maize with two degrees of fineness d1 = 1:25 mm and d2 = 2:00 mm was used as a tracer. Maize was covered with Rhodamine B, which emits red light under the influence of ultraviolet radiation. The tracer was introduced into the mixture before the mixing process began. Nine multicomponent grain mixtures were used. The proportion of fluorescent maize was evaluated on the basis of computer image analysis. Additionally, the fraction of the tracer was evaluated using a control method (validation of the accuracy of the proposed method). The results indicate that the degree of the tracer’s fineness influences the results obtained. The use of fluorescent maize with particle size d2 = 2:00 mm allowed to obtain results which differed less from the control method. The average size of the difference in results ranged from 0.20–0.38 for the 2.00 mm tracer and 0.38–1.34 for the 1.25 mm tracer.
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Authors and Affiliations

Dominika B. Matuszek
1
Jolanta B. Królczyk
2

  1. Opole University of Technology, Faculty of Production Engineering and Logistics, Department of Biosystems Engineering and Chemical Processes, Mikolajczyka 5, 45-271 Opole, Poland
  2. Opole University of Technology, Faculty of Mechanical Engineering, Department of Manufacturing and Materials Engineering, Mikolajczyka 5, 45-271 Opole, Poland
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Abstract

A review of the available literature shows that analyses of organic Rankine cycle systems with a zeotropic mixture working medium practically concern single-circuit systems. In these works, it has been shown that the standing of zeotropic mix-tures in organic Rankine cycle systems makes it possible to achieve higher power and efficiency compared to organic Rankine cycle systems with pure fluids. In this article, the authors present an analysis of the efficiency of a two-circuit organic Rankine cycle (binary) power plant with a zeotropic mixture in the upper cycle of this power plant. The proposed binary power plant system uses a zeotropic mixture circulating medium in the upper organic Rankine cycle circuit, while the lower circuit uses a homogeneous low-boiling medium. The results of this analysis showed that with properly selected parameters of the binary power plant system, i.e. with appropriate selection of the pressure during the evaporation trans-formation in the upper and lower circuits, the power obtained in it is higher than for a single-circuit power plant in the same temperature range (for the same heat source and the same condensing temperature). The increase in the power of the binary power plant system was achieved by using the heat contained in the water stream to preheat the medium in the bottom circuit. For example, for the binary organic Rankine cycle power plant with R413A refrigerant in the upper circuit, the generated power is 17.8 kWe, which is 20% higher than for a single-circuit power plant (for the reference power plant, the power is 14.8 kWe).
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Authors and Affiliations

Sławomir Wiśniewski
1
Michał Bańkowski
1

  1. West Pomeranian University of Technology, Faculty of Mechanical Engineering and Mechatronics, 19 Piastów Avenue, Szczecin

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