2020, Vol. 18, Special Issue 1

Selle kollektsiooni püsiv URIhttp://hdl.handle.net/10492/6026

Sirvi

Nüüd näidatakse 1 - 20 39

Utilization of fused deposition method 3D printing for evaluation of discrete element method simulations
(2020) Hnízdil, P.; Chotěborský, R.; Kuře, J.
FDM 3D printing is used for designing prototype assessment in engineering production. It is usually used to verify the functionality of kinematics mechanisms. It can also be used for innovation in agricultural production, eg. the development of new mechanisms for agriculture tools. Such a mechanism as well as the entire components is printed using FDM and they are made of plastics. This whole can be experimentally verified in a laboratory trough. The article deals with the verification of the possibilities of using FDM technology for the design of agricultural tools. The material properties, namely stress-strain, of the plastics after printing are entered into the Ansys mechanical library, and the DEM results are also imported into Ansys mechanical. Material properties of plastics for FDM technology such as PLA, PETG show that its mechanical properties limited their using for validation.
Characterization of materials used in the manufacture of ceramic tile with incorporation of ornamental rock waste
(2020) Luiz, N.F.; Cecchin, D.; Azevedo, A.R.G.; Alexandre, J.; Marvila, M.T.; Silva, F.C.; Paes, A.L.C.; Pinheiro, V.D.; Carmo, D.F.; Ferraz, P.F.P.; Hüther, C.M.; Cruz, V.M.F.; Barbari, M.
The production of ceramic tiles, such as tiles, has a great environmental impact, either in the extraction of natural raw materials or gas emissions in the burning stages. The use of industrial solid waste in ceramic materials can contribute to the reduction of these impacts, according to the characteristics of solid waste and its interaction with ceramic materials in the processing steps. Thus, this study aimed to characterize the materials needed to make a ceramic tile with incorporation of ornamental rock waste (ORW), thus evaluating its main characteristics regarding the feasibility of this incorporation. The physical characterization of the clays used in the production of ceramic artifacts was performed, and for the waste the mineralogical analyzes were performed, through x-ray diffraction (XRD), microstructure analysis from confocal optical microscopy, after sintering the prototypes and chemical analysis by X-ray spectroscopy (EDX). Soon after the raw materials went through the step of conformation and preparation of the prismatic specimens by the process of extrusion of the ceramic mass, with an incorporation of the ORW in 0% and 15% of the ceramic mass, for its subsequent The prototypes were sintered at three different temperatures (850 °C, 950 °C and 1,050 °C). The specimens were submitted to technological tests of mechanical resistance, water absorption, firing shrinkage and porosity to evaluate the incorporation viability. The results indicated the presence of quartz particles in all raw materials, and also that the clays of the study region are predominantly kaolinitic. The presence of these materials in the ceramic masses directly influences the micrographs, because they result in the formation of liquid phase, inert particles that can turn the site into a stress concentration point and when incorporated in the ORW the specimens met the technical specifications of the Brazilian standard for application on ceramic tiles. The results found in the technological tests carried out, that the incorporation of 15% of ornamental rock waste in both clays did not affect the tile properties, indicating the feasibility of incorporating this waste in civil construction, minimizing the impacts generated.
Comparison between the thermal properties of cement composites using infrared thermal images
(2020) Ferraz, P.F.P.; Mendes, R.F.; Ferraz, G.A.S.; Damasceno, F.A.; Silva, I.M.A.; Vaz, L.E.V.S.B.; Mendes, L.M.; Cecchin, D.; Castro, J.O.
The use of agribusiness residual lignocellulosic fibres can be a good alternative in the development of lignocellulosic composites. The current work aimed to investigate the thermal performance of cement-based composites with lignocellulosic materials: Eucalyptus, sugarcane bagasse, coconut fibre in comparison with commercial gypsum board to be used as internal partitions of the building using infrared thermal images. Three repetitions for each kind of lignocellulosic material were made, and three commercial gypsum boards were used. In the production of the panels, the following parameters were applied: material and cement ratio, 1:2.75; water and cement ratio, 1:2.5; hydration water rate of 0.25; additive, 4% (based on cement mass). The calculations were performed for a nominal panel density of 1,200 kg m- ³. The thermal analysis was performed in a chamber composed of MDP (Medium-Density Particleboard) and with an internal layer of rock wool and the heat source (thermal resistance). For the superficial temperature measurement, a FLIR E75 camera was used to capture the infrared images. When the internal temperature of the chamber stabilized at 50 °C, an infrared thermal image was collected from each side of the composite. Thermal properties were analysed: thermal conductivity, resistivity, resistance, and transmittance. Based on the results, sugar cane cement composites were characterized by higher values of thermal conductivity. Related to thermal resistivity, thermal resistance, and thermal transmittance, only the coconut panel presented similar behaviour to the commercial gypsum board. Thus, cement composite using coconut can be a potential alternative that might solve energy and environmental concerns simultaneously.
Features of the influence of copper nanoparticles and copper oxide on the formation of barley crop
(2020) Seregina, T.; Chernikova, O.; Mazhaysky, Yu.; Ampleeva, L.
In addition to modern methods of agricultural technology, currently the achievements of selection and genetics are widely used, as well as modern nanotechnology and nanomaterials, to improve food production. One of the forms of biologically active nanomaterials is metal nanopowders and their derivatives. The application is carried out in minimal doses that can significantly reduce costs in agricultural production. Improving the yield and quality of crops by optimizing nutrition and plant protection using nanotechnology and nanomaterials will solve not only the problems of increasing the yield and quality of farmed products, but also environmental problems. The purpose of this research was to determine the effect of copper and copper oxide nanoparticles on the formation of a barley crop. Under the conditions of a lysimetric experiment, the effect of presowing treatment of spring barley seeds by nanoparticles of copper and copper oxide on the growth and development of plants, yield, and their nutritional value was studied. The used nanoparticles have the following characteristics: Cu - 40–60 nm, phase composition: Cu - 100%; CuO - 40–60 nm, phase composition: CuO - 100%. A suspension of nanoparticles was obtained by dispersion by ultrasound in an aqueous solution. Nanopowders of copper and copper oxide in the solution contained 0.01 g per hectare seed rate. Barley seeds were soaked 30 minutes before sowing in double distilled water (control variant), as well as in a suspension of nanoparticles. Presowing treatment of barley seeds by Cu nanoparticles contributed to the intensification of growth processes, as well as an increase in green mass. The use of copper nanoparticles contributed to an increase in grain yield by 17.3% compared with the control, while there was no decrease in nutritional value: metabolic energy, feed units, digested protein. Based on the research results, it is preferable to use copper nanoparticles in comparison with copper oxide nanoparticles to obtain a higher barley yield.
Hydrogen sulfide emissions from cattle manure: experimental study
(2020) Vtoryi, V.; Vtoryi, S.; Gordeev, V.
Animal waste products, manure, in particular, are the sources of gases harmful to human and animal health. Hydrogen sulfide (H2S), which is produced from the breakdown of organic matter in animal faeces, is one of them. Its concentration in the cow barn air should not exceed 5 mg m−3 . A special laboratory setup was designed and the level of hydrogen sulfide emissions from the cow manure was determined depending on the time and manure temperature and moisture content. The most intensive emission of hydrogen sulfide from manure was in the first 24 hours – the increment of H2S concentration was 0.168 mg m−3 per hour average. During the next 24 hours, it was 0.021 mg m−3 per hour. When the manure temperature increased, H2S concentration increased also; when the temperature manure decreased, H2S concentration decreased also. In 48 hours, the hydrogen sulfide concentration was 1.1 mg m−3 at the manure temperature of +3.0 °C. At the manure temperature of +23.4 °C and 21.3 °C, H2S concentration was 6.53 mg m−3 and 4.97 mg m−3 , respectively. The higher was the manure moisture content, the lower was the emission of hydrogen sulfide into the environment. After 24 hours under the manure moisture content of 88.5% and 92.5% and its temperature of 21 °С ± 0.3 °С, the difference in the hydrogen sulfide concentration was 1.18 times depending on the manure moisture content. The selected regression equations described the dependence of the hydrogen sulfide concentration on the considered factors. The determination coefficients and Student's criteria proved the reliability of the results obtained at the significance level P ≤ 0.05.
Separation of reducing sugars from lignocellulosic hydrolysate: Membrane experiments & system dynamic modelling
(2020) Weerasuriya Arachchige, A.R.P.P.; Mezule, L.; Juhna, T.
Separation of fermentable sugars after hydrolysis of lignocellulosic biomass plays a vital role in second-generation biofuel production. Byproducts and solid fractions generated during pretreatment and hydrolysis can have adverse effects on fermentation efficiency. Previous studies have shown that a maximum of 40% (w/w) of sugar yield can be obtained by sequential UF and NF permeate recovery. This study aimed to introduce a multi-step membrane filtration process to recover fermentable sugars while removing inhibitory bi-products. Fermentable sugar recovery was investigated using a recirculation flow between various stages of separation. The experimental results demonstrated that by introducing NF permeate recirculation to the UF unit a sequential UF/NF system can achieve 60% (w/w%) recovery of reducing sugars. Based on the experimental results, a ‘Simultaneous ultrafiltration and nanofiltration model’ was developed using system dynamics. The model was used to predict the final sugar concentration and sugar yield using sugar permeability in each membrane as the dynamic variability. The model predicts that high sugar permeability (or selective permeability) through the ultrafiltration mostly affects the efficiency of the system, which still is a challenge.
Comparison of airflow homogeneity in Compost Dairy Barns with different ventilation systems using the CFD model
(2020) Fagundes, B.; Damasceno, F.A.; Andrade, R.R.; Saraz, J.A.O.; Barbari, M.; Vega, F.A.O.; Nascimento, J.A.C.
In the pursuit of high milk productivity, producers are using confinement systems in order to improve performance and animal welfare. Among the housing systems, the Compost bedded-pack barns (CBP) stand out. In these barns a bedding area is provided inside, where cows move freely. Generally this area is covered with carbon source material (such as sawdust or fine dry wood shavings) which together with manure, thanks a regular mechanically stirring, ensures the aerobic composting process. The ventilation in these facilities has the function of dehumidifying the air, improving the air quality, drying the bedding, improving the thermal comfort conditions of the confined animals. This work aimed at validating a computational model using Computational Fluid Dynamics (CFD) to determine the best homogeneity of airflows generated by different forced ventilation systems used in CBP barns. Two CBP barns were compared with different ventilation systems: high volume low speed (HVLS) and low volume high-speed (LVHS) fans. The results showed that the proposed model was satisfactory to predict the flows generated by both types of fans. It was concluded that the use of HVLS fans produced a more homogeneous airflow when compared to LVHS fans. The use of mechanical ventilation in tropical conditions is necessary for the proper functioning of the system. In this study, the systems used promoted the increase in air speed to levels close to adequate.
Study of transhydrogenase systems features in the mutants of the yeast pachysolen tannophilus for the production of ethanol and xylitol from agricultural wastes
(2020) Bolotnikova, O.; Bazarnova, J.; Aronova, E.; Bolotnikova, T.
The key catabolic enzymes of D-xylose, an important structural component of different agricultural wastes, were studied in cells of mutant strains of the xylose-assimilating yeast Pachysolen tannophilus. The evaluation of catalytic activity and cofactor specificity of xylose reductase (ЕС 1.1.1.307) and xylitol dehydrogenase (ЕС 1.1.1.9) confirmed the dependence of intracellular catabolic pathway for D-xy lose on the NAD×H/NADP×H ratio, formed under microaerobic conditions. The study of total activity of some NAD+ /NAP×H-dependent dehydrogenases revealed the metabolic characteristics of the yeast cells, which could ensure selective ethanol or xylitol production. Thus, the efficient involvement of D-xylose into the Embden–Meyerhof–Parnas pathway provided not only the high activities of xylose reductase and xylitol dehydrogenase, but also of 1-glycerophosphate dehydrogenase (EC 1.1.1.8) and lactate dehydrogenase (ЕС 1.1.1.27), respectively. The inhibition of activity of these enzymes led to selective production of xylitol from D-xylose. On the base of the experimental results, the principles of metabolic engineering of xylose-assimilating yeasts were formulated. The possibility of bioethanol and xylitol production from different agricultural wastes using xyloseassimilating yeasts are discussed.
Sustainability indicators in cooperative management of recyclable materials
(2020) Aramian, C.B.; Barcelos, F.; Silva, F.C.; Cecchin, D.; Azevedo, A.R.G.; Carmo, D.F.
Following the promulgation of the National Solid Waste Policy in 2010, legal provisions, government programs and sectoral agreements have been implemented, but without the expected efficiency in relation to recycling. It should be noted that Cooperatives of Recyclable Material Pickers (CRMP) should play a leading role in this regard, but they do not have adequate management to be economically, socially and environmentally sustainable, depending on assistance to maintain the activity. Aiming to elucidate this issue, in this paper was made an institutional diagnosis of the category of waste pickers using the Gramacho region in the city of Duque de Caxias (Rio de Janeiro) as a case study. It was carried out an evaluation of the historical context of the neighbourhood, and it was drawn up a semi-structured questionnaire in 12 of the 18 cooperatives in the region. The data were interpreted through a SWOT matrix and the Venn diagram. A matrix was proposed and elaborated with 15 sustainability indicators specific to the CRMC reality in order to evaluate and monitor the management of cooperatives. After collecting the primary data, it was possible to validate the matrix of indicators with indexes of cultural, economic, political and ecological sustainability of the cooperatives. It was found that the matrix of indicators facilitated the understanding of the data and the comparison between the indicators. This tool can help decision-making, creation of action plans and identification of demands by the cooperative waste pickers themselves, without the presence of an analyst or technician.
Variable velocity system for evaluating effects of air velocity on Japanese quail
(2020) Vilela, M.O.; Gates, R.S.; Zolnier, S.; Barbari, M.; Teles Junior, C.G.S.; Andrade, R.R.; Rocha, K.S.O.; Tinôco, I.F.F.; Souza, C.F.; Conti, L.; Rossi, G.
This study documents the design and performance of a system to apply different magnitudes of air velocity to Japanese quail, to evaluate the combined effects of velocity, temperature and humidity on bird behaviour, performance and welfare. The system was developed to simulate observed field conditions ocurring in regions with high winds where quail are raised in curtain-sided housing. System performance consisted of characterizing air velocity distribution in cages downstream of the air velocity which was directed at the front of the cages. The system consisted of two fans attached to a 25 cm PVC tube, one at each end, with the outlet airflow directed through a continuous slot over the cage front at the feeder. The design and performance of this experimental system was evaluated, with six such systems were built and utilized in research trials. To assess system performance, air velocity was measured at 275 points per cage uniformly arranged along the three dimensions (length, width and height) in eight cages with zero, 1, 2 or 3 m s-1 nominal velocity setpoints. Spatial distribution of velocity was analysed by mapping and from descriptive statistics, with attention to the zone closest to the feeder where birds must go to eat. There was no significant difference (P > 0.05) found in mean paired difference of air speed data measured for pairs of front portion cages with similar velocities. A significant positive correlation was found (P < 0.001) between the measured air velocity at paired points in the cages subjected to the same velocity treatment. A comparison of measured mean air velocity to the nominal setpoint values used for experiments indicated that careful attention to outlet adjustment is important, especially at higher nominal velocity setpoint as 3 (± 0.10) m s-1 which was difficult to achieve with the system. An example of the use of the deployment of the variable velocity system in controlled environment chambers with Japanese quail is provided.
Airflow profile study of a compost dairy barn using a low-cost 3D-printed anemometer network
(2020) Vega, F.A.O.; Rios, A.P.M.; Damasceno, F.A.; Saraz, J.A.O.; Nascimento, J.A.C.
Mechanical ventilation is commonly used for environmental thermal regulation inside closed-field agricultural production systems. Analyzing the air distribution inside these facilities and the correct operation of the fans can be a challenging. This could be determined using cost prohibitive techniques as particle image velocimetry or deploying large wind sensors networks on-site. To avoid this limitation without a lack of measurement accuracy, this research was focused on developing and test a low-cost anemometer network based in low cost propeller’s anemometers, built using fused 3D-printed and open-hardware platforms. Four propeller anemometers with three to six blades were simulated using the 6-DOF method of ANSYS computer fluid dynamics software. Similar results were obtained for all the simulated models with minor differences. Anemometers were tested in an open circuit wind tunnel before to be evaluated in two open compost dairy barn building using high-volume low-speed and low-volume high-speed fans. Data were analyzed by employing contour maps, descriptive statistics and correlation. The results show that the anemometer network determines the fan’s wind profile for wind speeds over 0.7 m s-1 and it was possible to determine the facilities spots with ventilation problems. The proposed anemometer network and methodology are a good alternative to analyze the operating conditions of the tested agricultural facilities and optimize its performance.
Investigation of dual varying area flapping actuator of a robotic fish with energy recovery
(2020) Tipans, I.; Viba, J.; Irbe, M.; Vutukuru, S.K.
Autonomous under-water vehicles (AUV) performing a commanded task require to utilize on-board energy sources. At the time when on-board power source runs low during operation, the vehicle (AUV) is forced to abort the mission and to return to a charging station. The present work proposes the technique of an energy recovery from surrounding medium. This effect is studied for dual action actuator movement that obtains energy from fluid. It is realized that a flapping or vibrating actuator can be used for energy extraction phenomenon apart from the non-traditional propulsive technique. In the present work a simple dual flapping actuator that can switch between simple flat plate and perforated plate at extreme end positions (angles) by using an efficient mechatronic mechanism that would help in overcoming viscous forces of the operating medium is extensively studied. The main objective of the present article is to develop a new approach for energy gain and recharge power pack of on-board sources from the surrounding medium and to create a robotic fish that would work autonomously by using unconventional drive along with the possibility of energy restoration by using dual varying area type vibrating actuator. At the time of recharge, the robotic fish would project its tail (actuator) out of water and use surrounding medium (air) to scavenge the energy. All the equations describing the process are formed according to classical laws of mechanics. The mechatronic system is explained and the results obtained are discussed in detail for air as the operating fluid to scavenge energy.
Morpho-physiological effects of Stymjod foliar application on Dactylis glomerata L.
(2020) Sosnowski, J.; Jankowski, K.; Truba, M.; Novák, J.; Zdun, E.; Skrzyczyńska, J.
The aim of the experiment was to study the effects of foliar application of a growth regulator containing iodine nanoparticles, with the trade name of Stymjod, on morphometrics, photosynthetic activity and chlorophyll content of Dactylis glomerate L. The following parameters were determined: the weight of fresh and dry matter of plants, leaves and roots, the number of shoots and leaves, potential (FV/Fm) and effective (F/Fm’) quantum efficiency of photosystem, photochemical (qP) and non-photochemical (qN) quenching, as well as chlorophyll a and chlorophyll b content in leaf blades. The pot experiment was carried out in a breeding room. Stymjod was applied at 1.5%, 3% and 4.5% concentrations in the spray solution. It is a nanotechnology-based growth regulator, with easily assimilable forms of mineral and organic ingredients, favorably affecting plant ontogenesis. Plants were treated twice with a single dose of 50 mL of spray per pot. They were sprayed till they were completely covered with the liquid. Distilled water was used to spray control plants. The results were statistically processed using analysis of variance, while the significance of the differences between means was determined with Tukey's test with P = 0.05. In the experiment it was found that different concentrations of Stymjod in the spray resulted in different response of plants. The best morphological effects were obtained using the concentration of the product exceeding 3%. In the test conditions Stymjod applied to D. glomerata increased the efficiency of the photosynthetic apparatus and the content of chlorophyll pigments.
Comparison of phosphorus removal efficiency of conventional activated sludge system and sequencing batch reactors in a wastewater treatment plant
(2020) Denisova, V.; Tihomirova, K.; Neilands, J.; Gruskevica, K.; Mezule, L.; Juhna, T.
The aim of this study was to evaluate the effectiveness application of sequencing batch reactors (SBRs) for phosphorus removal compared to the conventional activated sludge (CAS) treatment system. The results showed that the removal efficiency of phosphorus reached about 99% at wastewater treatment plant with CAS system. At the same time, the maximum phosphorus removal efficiency can be achieved to 88% if the SBRs system operating parameters are optimized. Finally, this study demonstrated that even if granules are not fully developed, the SBR system is working with a good efficiency.
Recognition of retroreflective traffic signs by a vehicle camera system
(2020) Khrapova, M.; Růžička, M.; Trnka, V.
The systems of traffic sign recognition are based on the evaluation of three components of every sign: shape, colour and pictogram. There are different factors that can have an influence on the efficiency of detection and recognition of these components. One of the most important factors is the quality of the retroreflective sign surface. Retroreflective sheeting improves the readability of colour and pictogram of traffic sign by increasing brightness of its background and/or legend elements. The aim of the paper is to provide a comprehensive survey of the efficiency of sign’s recognition by a modern vehicle camera system. The traffic sign sheeting was measured by the handled retroreflectometer. Then this measurement was repeated by the modern camera system used for recognition of traffic signs in the vehicle. The results of this paper present the analysis of the recognition efficiency of traffic signs and the overview of other factors that can have a significant impact on sign detection and recognition distance. The results can be used for creation a traffic sign database for learning-based recognition techniques to vehicle camera systems.
New approach for recycling spare parts, components and assemblies
(2020) Mitrofanovs, V.; Boiko, I.; Geriņš, Ē.
Recycling and disposal are one of the most complicated topics in the lifecycle of a mechanism, especially in case of previous generations of machines that were designed without taking any care of post exploitation period. In the current work, the ‘feasibility points’ of recycling units, methods of recycling as well as pricing formation for recycling materials, reviewed and proposed by several world universities and scientific bureaus and applied by major world brands have been analysed. The general principles that should be rated as a basis when designing and creating new mechanisms, as well as the actions which we consider as a necessary supplement to the existing rules of the lifecycle of assemblies and which should be applied in practice, were introduced by authors in the ‘Management of parts and components for units and assemblies in mechanical engineering industry and its impact on the environment’. It was discovered that even modern assemblies, not to mention previous generations, are being designed without taking into consideration any possibilities of easy recycling the used materials. The number of components of mechanisms, which are being repaired as assemblies, is continuously increasing, while maintainability and repairability of separate parts is decreasing. Taking into account the state of the art in the field, the new approach for promoting the reusing natural resources and decreasing the harmful effects of obsolete components of mechanisms on the environment is proposed. Thus, using the fast-moving parts that in post operational period can be easily detailed by type of a material will ensure more efficient consumption of natural resources. Our research and developments significantly reduce the costs of recycling and these materials become competitive comparing to the new ones. Taking into account the state of the art in the field, the new approach for promoting the reusing natural resources and decreasing the harmful effects of obsolete components of mechanisms on the environment is proposed.
Thermal decontamination of sewage sludge
(2020) Dubova, L.; Strunnikova, N.; Cielava, N.; Alsina, I.; Kassien, O.; Bekker, A.
Every year a huge amount of sewage sludge is formed at municipal wastewater treatment plants. Sewage sludge contains a sufficient amount of biogenic elements and organic components, which characterizes them as possible raw materials for the production of organic fertilizers. However, direct incorporation of these sediments into the soil is impossible due to the fact that, in addition to useful organic and mineral components, they contain pathogens, viruses and helminth eggs. The aim of the study was to optimise thermal disinfection conditions for preparing of safety sewage sludge fertilizer. Laboratory studies were carried out using sediments from wastewater treatment plants of some cities. During laboratory experiments, the conditions for thermal disinfection of sediments – the thickness of the sediment layer, the air temperature in the disinfection furnace, and the treatment time of the sediment – were determined. When conducting industrial tests of a conveyor-type sediment decontamination furnace, the operating conditions of the furnace were determined, i.e., the temperature regimes of the sludge heating zone, the decontamination zone and the cooling zone, and the optimum parameters of the sludge layer thickness on the conveyor and the conveyor speed were determined.
Qualimetry as productivity criteria in metal-cutting operations
(2020) Maksimov, D.; Kalkis, H.; Perevoschikov, Y.; Roja, Z.
The qualimetry method will allow an objective assessment of the performance of metal-cutting machines and the production capacity of machinery, as well as an objective assessment of their use in multi-product manufacturing, applying the qualimetry approach and qualimetry indicators, which are based on the concept of qualification of metal removing during machine operations. The aim of the study is to develop methods for measuring the performance of metal-cutting machines and open the way to create a regulatory framework based on quantitative indicators of the equipment quality. Qualimetry measured volume of metal removing allows setting the maximum possible productivity (quali-power) of metal cutting machinery, based on a small number of basic quality indicators contained in the machinery data sheets. It is essential that the quali-power of the machinery is an objective indicator of its quality, independent of the specific conditions of its operation at any given time. Hence the productivity criteria in metalworking cutting operations can be measured.
Investigation in fuel consumption of a hybrid and conventional vehicle
(2020) Šmigins, R.; Pīrs, V.; Berjoza, D.
During the last decade the introduction of more environmentally friendly technologies were raised more rapidly by the decline in the global fossil energy resources and the increased negative environmental impact of conventional vehicles. One of such technology is the hybrid, which is currently making the transition from conventional vehicle with internal combustion engine to an electric vehicle. At this time there exist a lot of offers of such vehicles from different manufacturers, but there do not exist many researches connected with real hybrid performance in different road cycles and conditions allowing evaluate its real economical performance. This research was realized with the aim to evaluate performance and fuel consumption of hybrid electric vehicle and its conventional internal combustion engine analogue in laboratory conditions. Tests were realized with two new Toyota Yaris vehicles in Alternative Fuels and Research Laboratory on chassis dynamometer MD-1750 using AVL KMA Mobile system. The results showed better adaptation of Toyota Yaris Hybrid to urban operation, demonstrating 21.3% lower fuel consumption than Toyota Yaris conventional gasoline vehicle, accordingly 7.29 and 8.84 L (100 km)-1.
Development of hemp hurd particleboards from formaldehyde-free resins
(2020) Alao, P.; Tobias, M.; Kallakas, H.; Poltimäe, T.; Kers, J.; Goljandin, D.
Low density of hemp hurd (Cannabis Sativa L), better end of life impact, performance comparable to wood chips and low energy requirement for cultivation make it a suitable alternative raw material for particleboards (Pb). However, due to concerns about sustainability and formaldehyde emissions, it is essential to develop the new bio-based resins from renewable resources. In this research, the mechanical and physical properties of Pb produced from hemp hurds (HH) and a variety of resins: Urea-formaldehyde (UF), formaldehyde-free acrylic resin (Acrodur®) and bio-based soy resin (Soyad™) were compared to those of wood particles (WP) bonded with UF. The results indicate that boards from HH are generally lighter than WP with a 5.6% variation between HH+UF and WP+UF. Hemp boards based on soy-resin showed higher tensile performance, with an average of 0.43 MPa compared to the 0.28 MPa and 0.24 MPa of (HH+UF) and (WP+UF) respectively. Nevertheless, thickness swelling (TS) of HH+UF (27%) was the least, while there was no significant difference in the water absorption (WA) compared to HH+Soyad4740, both were still lower than that of WP+UF. The overall outcome shows that bio-based soy resin can be a suitable alternative to UF as a binder in Pb production.

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