Tag Archives: temperature

xxx J.I. Orisaleye, S.O. Jekayinfa, R. Pecenka and T.B. Onifade
Effect of densification variables on water resistance of corn cob briquettes
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Effect of densification variables on water resistance of corn cob briquettes

J.I. Orisaleye¹, S.O. Jekayinfa², R. Pecenka³* and T.B. Onifade²

¹University of Lagos, Faculty of Engineering, Department of Mechanical Engineering, PMB 56, Akoka, Nigeria
²Ladoke Akintola University of Technology, Faculty of Engineering and Technology, Department of Agricultural Engineering, PMB 4000, Ogbomoso, Nigeria
³Leibniz Institute for Agricultural Engineering and Bioeconomy, ATB, Department of Post-Harvest Technology, Max-Eyth-Allee 100, DE14469 Potsdam, Germany
*Correspondence: rpecenka@atb-potsdam.de

Abstract:

Solid biofuels can be used in heat and power generation applications. The utilization of agricultural residues for this purpose would be of immense benefit to rural communities of developing countries where the resource is being produced. Water resistance is a crucial property for transport and storage of biomass briquettes under moist climate conditions. In this study, the effect of process and material variables on the water resistance property of corn cob briquettes was investigated. The water resistance of briquettes produced ranged between 32.6 and 94.8% for die temperature between 90 °C and 120 °C, hold time from 7.5 to 15 minutes and die pressures between 9 and 15 MPa. A higher die temperature resulted in an increase in the water resistance of the biomass briquettes. Also, increasing the hold time improved the water resistance of the briquettes. Using a particle size less than 2.5 mm resulted in higher briquette water resistance property compared to briquettes produced from particle sizes greater than 2.5 mm. It was also shown that the effect of the interaction of the temperature with particle size on the water resistance of corn cob briquettes was statistically significant (p < 0.05).

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xxx L. Dubova, A. Senberga, I. Alsina, L. Strauta and I. Cinkmanis
Development of symbiotic interactions in the faba bean (Vicia faba L.) roots
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Development of symbiotic interactions in the faba bean (Vicia faba L.) roots

L. Dubova¹*, A. Senberga¹, I. Alsina¹, L. Strauta² and I. Cinkmanis³

¹Institute of Plant and Soil sciences, Latvia University of Life Sciences and Technologies, Faculty of Agriculture, Liela street 2, LV-3001 Jelgava, Latvia
²Laboratory of Biotechnology, Latvia University of Life Sciences and Technologies, Strazdu street 1, LV-3004 Jelgava, Latvia
³Department of Chemistry, Faculty of Food Technology, Latvia University of Life Sciences and Technologies, Liela street 2, LV-3001 Jelgava, Latvia
*Correspondence: Laila.Dubova@llu.lv

Abstract:

Double-inoculation of faba bean (Vicia faba L.) seeds before sowing with rhizobium bacteria and mycorrhizal fungi is a known agronomic practice. It improves symbiotic nitrogen fixation and enhances legume supply with mineral elements and water. Effective symbiosis makes it possible to replace some of the required mineral fertilizer needed for plant growth with symbiotically fixed. This will ensure more environmentally friendly agricultural production. The formation of an effective symbiosis depends on a number of biotic and abiotic factors affecting the biochemical signals released by the partners. The biochemical mediator for symbiosis formation is flavonoids. The aim of this experiment was to test the effects of rhizobial and mycorrhizal inocula on symbiosis formation under different temperatures. Beans are an important source of protein for animal feed and human consumption. Four cultivars of faba beans were used – two V. faba var. minor Beck. -‘Fuego’ and ‘Lielplatone’, and two V. faba var. major Harz. – ‘Bartek’ and ‘Karmazyn’. The combination of microorganisms for seed inoculation influenced the frequency of root mycorrhization and abundance of arbuscules. The content of flavonoids in seed exudates correlated (r = 0.93) with germination temperatures. The use of mycorrhizal fungi alone or in combination with rhizobia reduced the amount of flavonoids in the bean seed exudate. In the pot experiment the amount and size of nodules significantly differed between cultivars. Use of mycorrhizal preparation mitigated the effect of inadequate germination temperature. Higher degree of mycorrhization and more intense formation of arbusculs formation was observed in the bean roots grown in vegetation pots in comparison with field ones. Local bred ‘Lielplatone’ had significantly better compatibility with microsymbionts in local agroclimatic conditions.

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1062–1070 V. Kolář, M. Tichý, M. Müller, P. Valášek and A. Rudawska
Research on influence of cyclic degradation process on changes of structural adhesive bonds mechanical properties
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Research on influence of cyclic degradation process on changes of structural adhesive bonds mechanical properties

V. Kolář¹*, M. Tichý¹, M. Müller¹, P. Valášek¹ and A. Rudawska²

¹Czech University of Life Sciences, Faculty of Engineering, Department of Material Science and Manufacturing Technology, Faculty of Engineering, Kamýcká 129, CZ165 21 Prague, Czech Republic
²Lublin University of Technology, Department of Production Engineering, Mechanical Engineering Faculty, Nadbystrzycka 36, PL20 618 Lublin, Poland
*Correspondence: vkolar@tf.czu.cz

Abstract:

The paper deals with an influence of a cyclic degradation process on changes of a shear tensile strength of single lap-shear adhesive bonds and their elongation according to ČSN EN ISO 9142. Five one-component structural adhesives used in a construction of car body works were used within the research. The degradation of adhesive bonds is a significant factor which influences a quality and a service life of adhesive bonds exposed to environment. A main requirement in production companies is not only reaching satisfactory initial mechanical properties but namely ensuring a reliability and a safety of adhesive bonds during their usage.
These reasons show a great importance of adhesive bonds tests either directly in the operating environment or by a simulation of operating conditions in laboratories. The degradation process of adhesive bonds worsens mechanical properties of not only the bond itself but also of the bonded material. This process is progressing and it is usually permanent and irreversible. It is a change of mechanical and physical properties which can endanger a safety and a reliability of parts, prospectively of the whole equipment. It can leads up to a complete failure of its function in the extreme case. A temperature, a moisture, a direct contact with water and chemicals or an atmospheric corrosion belong among the most serious degradation agents. It is important to take into regard time of the processes influence at the same time which can act either independently or concurrently when their effects grow stronger.
From that reason the adhesive bonds were exposed to the cyclic degradation process according to the standard ČSN EN ISO 9142. Subsequently, the adhesive bonds mechanical properties were tested on universal testing machine and by means of SEM analysis (TESCAN MIRA 3).
Results of mechanical tests proved a fall of the shear tensile strength of single lap-shear adhesive bonds after 42 cycles of the degradation process of 12.8 to 21.7%. The bond strength fall was gradual and it showed a linear trend at some adhesives. Other adhesives showed a significant fall after the exposition to the degradation process after which the strength fall stabilized.

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491–498 P. Kic
The course of drying and colour changes of alfalfa under different drying conditions
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The course of drying and colour changes of alfalfa under different drying conditions

P. Kic

Czech University of Life Sciences Prague, Faculty of Engineering, Department of Technological Equipment of Buildings, Kamýcká 129, CZ165 21 Prague, Czech Republic
*Correspondence: kic@tf.czu.cz

Abstract:

One of the conditions for successful livestock breeding and efficient livestock production is to ensure quality feed. High quality feed for livestock is alfalfa, which has a very high nutritional value and its cultivation is also important for crop production in terms of improving the soil structure and nitrogen enrichment. The aim of this paper is to inform about the experimental investigations of alfalfa drying and colour changes under different drying conditions. The results of natural convection at 27.5 °C and 40% relative air humidity are compared with forced convection at 1.2 m s-1 air flow velocity at the same air temperature and with results of drying by natural convection at 50 °C. The dry matter content was measured gravimetrically after drying in a hot air dryer at 105 °C. Higher drying rates shorten the time required for drying and earlier preservation and storage in the hayloft or in the hay bales. This reduces the risk of wetting of feed such by rain and degradation by fungi, etc. A shorter drying time is also important in terms of energy savings. The precise knowledge of the drying process and drying curves allows also to determine the appropriate time for storage and conservation for production of another type of fodder e.g. haylage or silage. The measurement results show a positive effect of higher drying speeds as well as increased air temperature. Higher drying air temperature during convection led to the partial lightening and greater yellowing of the feed.

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2088-2096 S. Kumar, J. Cerny and P. Kic
Air-conditioning in the cabins of passenger
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Air-conditioning in the cabins of passenger

S. Kumar*, J. Cerny and P. Kic

Czech University of Life Sciences Prague, Faculty of Engineering, Department of Technological Equipment of Buildings, Kamýcká 129, CZ165 21, Czech Republic
*Correspondence: surenderduhan88@gmail.com

Abstract:

The objective of this paper is to analyse the current state of the constructional design and operational conditions of air-conditioning device in passenger cars. The research was focused on the function of air-conditioning equipment of passenger cars Skoda and KIA in various modes of operation during the winter, spring and summer season at different levels of air conditioning (without air-conditioning, minimum, medium and maximum level). Air temperature, air humidity, globe temperature, CO2 concentration, dust concentration and noise inside the cabin were measured. Solar radiation plays a big role to rise up temperature inside the cabin. It resulted in the higher values of globe temperature than temperature of the air. The results of the measurements showed that CO2 values were significantly lower than 2,500 ppm at minimum air-conditioning, lower than 600 ppm at medium and lower than 500 ppm at maximum level of air-conditioning. For all vehicles, dust concentration was greater when it measured with the air conditioning switched off than with the air conditioning system turned on. The measurements confirmed that the total dust concentration was not more than 47 μg m-3, PM10 lower than 28 μg m-3 and PM1 lower than 27 μg m-3. The noise levels ranged from 49.1 to 68.7 dB(A). The air-conditioning had very positive impact on the inside comfort in car cabins from all points of view during all periods of the year.

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943-951 A. Avotins, P. Apse-Apsitis, J. Bicāns and J. Gruduls
Development and testing results of IoT based air temperature and humidity measurement system for industrial greenhouse
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Development and testing results of IoT based air temperature and humidity measurement system for industrial greenhouse

A. Avotins¹*, P. Apse-Apsitis¹, J. Bicāns¹ and J. Gruduls²

¹Riga Technical University, Institute of Industrial Electronics and Electrical Engineering, Azenes 12, LV-1048 Riga, Latvia
²SIA “Latgales darzenu logistika” greenhouse, “Kloneshniki”, Mezvidi parish, LV-5725 Karsava region, Latvia
*Correspondence: ansis.avotins@rtu.lv

Abstract:

Industrial greenhouse control systems are changing and getting new capabilities, due to the evolution of the Internet of Things (IoT) technologies, allowing wirelessly integrate various sensor technologies and create a cloud-based database and analytic solutions. Greenhouse systems typically are controlled by consuming single temperature and humidity measurement unit data (treated as an average value), this raises a question about the precision of such approach for application in a large industrial greenhouse. In this article IoT based temperature and humidity measurement system uMOL architecture is described and first measurement results of multi-point data collection with high resolution compared to existing single-point measurements.

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760–766 E. Kucuktopcu, B. Cemek and P. Banda
Determination of poultry house indoor heating and cooling days using degree-day method
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Determination of poultry house indoor heating and cooling days using degree-day method

E. Kucuktopcu*, B. Cemek and P. Banda

University of Ondokuz Mayis, Faculty of Agriculture, Department of Agricultural Structures and Irrigation, TR 55139 Samsun, Turkey
*Correspondence: erdem.kucuktopcu@omu.edu.tr

Abstract:

In poultry production, degree-day values are used as fundamental design parameters considered among others in determining the extent of heating and cooling of poultry housing. In this study, heating and cooling data values for each of broiler production period were determined using the degree-day method. The total length of the experiment was 123 days which corresponds to 3 growing periods. The inside and outside air temperatures of the poultry house were measured using air temperature data loggers positioned at different points and heights within and outside broiler house. Knowledge of heating and cooling day values is important as it necessitates the provision and maintenance of ideal bird’s production conditions and ensuring the economic viability of the enterprise through optimized energy consumption.

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700–706 J. Hart, and V. Hartová
The next generation of multiple temperature sensor
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The next generation of multiple temperature sensor

J. Hart¹,* and V. Hartová²

¹ Czech University of Life Sciences Prague (CULS), Faculty of Engineering, Department of Technological Equipment of Buildings, Kamýcká 129, CZ165 21 Prague, Czech Republic
² Czech University of Life Sciences Prague (CULS), Faculty of Engineering, Department of Vehicles and Ground Transport, Kamýcká 129, CZ165 21 Prague, Czech Republic
*Correspondence: janhart77@gmail.com

Abstract:

Long-term and short-term measurements of temperature at different depths in soil have always been very complicated. The solution that was used until now was measuring using soil thermometers. Measurements were done at shallow depths and generally only allowed for measuring of one temperature, and always at the one depth which was determined for the measurement (normally 5, 10, 20, 50, 100, 150 and 300 cm). These problems were relatively limiting and impractical. It was therefore necessary to devise an alternative for a simple and effective solution that would eliminate these disadvantages – it was necessary for a probe to allow temperature to be measured at different depths at one measuring point without having to change its position. A requirement simultaneously arose for the need to be able to measure temperatures at greater depths, and a multiple probe was therefore conceived consisting of a rod for dynamic penetration tests.

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1488–1497 P. Vaculik, L. Chladek, M. Prikryl, A. Smejtkova and P. Brany
The temperature changes of barley malt during its disintegration on a two roller mill
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The temperature changes of barley malt during its disintegration on a two roller mill

P. Vaculik*, L. Chladek, M. Prikryl, A. Smejtkova and P. Brany

Czech University of Life Sciences Prague, Faculty of Engineering, Department of Technological Equipment of Buildings, Kamýcká 129, CZ 165 21 Prague 6-Suchdol, Czech Republic; *Correspondence: vaculik@tf.czu.cz

Abstract:

This article discusses the change of temperature during disintegration on two roller mill. The production of barley and its treatment to malt is first step of beer brewing. The malt is the produced in malt plants. Crushing the malt is realized in only the brewery and is a core activity of brewing technology. This operation is performed both in craft breweries and in industrial brewery. This article therefore is focused on the theory of crashing solid phase with a respect of development of heat. Grinding barley malt is realised using mills of various designs or disintegrators. They are widely used mills with 2, 4, 5, 6 grinding cylinders. These roller mills are used in many other applications, not only in industrial food or drink production. For next treatment solid phase should be broken into smaller pieces (comminuted). The greater the extent of comminution, the large the surface area for impact on next treatment. The amount of mechanical energy converted to heat energy depends on the principle of the process disintegration and other parameters, i.e. distance of grinding gap, capacity, mechanical properties of crashing material etc. For these reasons, it is important to pay attention to the temperature change of barley malt during its disintegration on a mill.

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1434–1441 A. Põldvere, A. Tänavots, R. Saar, S. Sild and L. Lepasalu
Effect of heat treatment at constant 120 °C temperature on the rheological and technological properties of pork
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Effect of heat treatment at constant 120 °C temperature on the rheological and technological properties of pork

A. Põldvere¹⋅²⋅*, A. Tänavots², R. Saar¹, S. Sild¹ and L. Lepasalu¹

¹Estonian University of Life Sciences, Institute of Veterinary Medicine and Animal
Sciences, Department of Food Science and Technology, F.R reutzwaldi 56/5,
EE51014 Tartu, Estonia
²Estonian University of Life Sciences, Institute of Veterinary Medicine and Animal
Sciences, Department of Animal Genetics and Breeding, F.R. Kreutzwaldi 62,
EE51014 Tartu, Estonia
³Estonian Pig Breeding Association, Aretuse 2, EE61411 Märja, Tartumaa, Estonia
*Correspondence: aarne.poldvere@emu.ee

Abstract:

The aim of the study was to evaluate the influence of low-temperature heat treatment on the physical and technological properties of pork. The Longissimus thoracis muscles from four pigs were used to determine the quality indicators of pork at 24 hours after slaughtering. Meat samples were cooked at constant 120 °C in a cooking bag until the internal temperatures of 62, 67, 72, 77 and 82 °C. Raw meat was the darkest and differed considerably (P < 0.05) from the heat-treated meat. The colour values of the heat-treated meat differed slightly among internal temperature phases. The ultimate pH value of raw meat also differed significantly (P < 0.05) from that of cooked meat. The pH value of cooked meat varied only within the range of 0.05 units. The electrical conductivity of muscle decreased gradually as the temperature increased. In case of heat-treated meat, the cooking loss increased considerably (from 18.88% to 31.73%) along with the increase in the internal temperature. The Warner-Bratzler shear force value was the highest (38.50 N) in the meat cooked until 77 °C, and the lowest (28.51 N) in that cooked until 67 °C. Strong negative correlation (P < 0.001) between electrical conductivity and cooking loss was observed during the heating procedure. Heat treatment can significantly decrease the electrical conductivity and increase the cooking loss of meat. Meat was the toughest when the internal temperature was 77 °C. However, the best rheological properties were observed in the meat cooked until the internal temperature of 72 °C.

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