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xxx M. Polák
The influence of changing hydropower potential on performance parameters of pump in turbine mode
Abstract |
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The influence of changing hydropower potential on performance parameters of pump in turbine mode

M. Polák

Czech University of Life Sciences in Prague, Faculty of Engineering, Kamýcká 129, CZ16521 Praha 6, Czech Republic
Correspondence: karel@tf.czu.cz

Abstract:

Various types of hydromotors that enable energy recovery simultaneously with the required pressure reduction can be used in the field of fluid pumping systems. Similar principle is applied, for example, in the case of use of hydrodynamic pumps in turbine mode (PAT), which are also used as an alternative to conventional turbines in small hydropower plants. However, these pumps do not usually have the possibility of regulating hydraulic parameters, as it is common with conventional turbines. This specific feature needs to be taken into account, when designing such system. Article analyses computational methods for the conversion of the performance characteristics and compares these results with experimentally measured data on a particular pump in turbine mode. The results indicated that conversion can be well used in practice to predict outputs as well as to determine the optimum total head and flowrate to ensure maximum efficiency of PAT operation. Further computations were influenced by deviations resulting from the change in efficiency during PAT operation.

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xxx V. Chiteculo, A. Brunerová, P. Surový and M. Brožek
Management of Brazilian hardwood species (Jatoba and Garapa) wood waste biomass utilization for energy production purposes
Abstract |

Management of Brazilian hardwood species (Jatoba and Garapa) wood waste biomass utilization for energy production purposes

V. Chiteculo¹*, A. Brunerová²*, P. Surový¹ and M. Brožek²

¹Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Department of Forest management, Kamýcká 129, CZ165 00 Prague, Czech Republic
²Czech University of Life Sciences Prague, Faculty of Engineering, Department of Material Science and Manufacturing Technology, Kamýcká 129, CZ165 00 Prague, Czech Republic
*Correspondence: brunerova@tf.czu.cz; chiteculo@fld.czu.cz

Abstract:

In the Federative Republic of Brazil, Jatoba (Hymenaea courbaril) and Garapa (Apuleia leiocarpa) trees are intensively harvested. The yield of one log is approximately 45–55%, which indicates a great amount of produced wood waste biomass.Present research monitored the suitability of wood waste biomass from Jatoba and Garapa trees for bio–briquette for solid biofuel production. The research was focused on chemical parameters,and energy potential of such biomass kinds. Jatoba wood waste biomass was used for the production of bio–briquette fuel and its final mechanical quality was investigated by determination of their mechanical quality indicators. Results of chemical analysis (in wet basis) exhibited great level of ash content in case of both species (Jatoba – 0.31%, Garapa – 3.02%), as well as high level of energy potential; net calorific value equal to 18.92 MJ kg–1 for Jatoba and to 18.395 MJ kg–1 for Garapa. Analysis of elementary composition proved following levels of oxygen content: Jatoba – 41.10%, Garapa – 39.97%. Mechanical analysis proved bio–briquette samples volume density ρ equal to 896.34 kg m–3 which indicated quality bio–briquette fuel, while the level of rupture force RF occurred at a lower level – 47.05 N mm–1. Most important quality indicator, the mechanical durability DU, unfortunately, occurred at a lower level; DU = 77.6% compared to the minimal level of bio–briquette fuels intended for commercial sales which must be > 90%. Overall analysis proved materials suitability for energy generation purpose with certain limitations which can improve by changing production parameters of briquetting.

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529–542 R.R. Rodrigues, S.C. Pizetta, G.M. Pereira, M.E.P.C. Jaeggi, R.S. Rocha,, I.M. Pereira, D.P. Cruz, J.N. Batista, R.K.G. Silva, P.M. Bernardes, A.S. Fonseca, G.C. Entringer and G.A. Gravina
Potential for macro and micronutrients extraction from tomato plants with different soil water stresses
Abstract |
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Potential for macro and micronutrients extraction from tomato plants with different soil water stresses

R.R. Rodrigues¹, S.C. Pizetta¹, G.M. Pereira¹, M.E.P.C. Jaeggi², R.S. Rocha²,*, I.M. Pereira², D.P. Cruz², J.N. Batista², R.K.G. Silva², P.M. Bernardes³, A.S. Fonseca⁴, G.C. Entringer² and G.A. Gravina²

¹Federal University of Lavras (FULA). Aquenta Sol, Lavras - MG, 37200-000, Brazil
²State University of North Fluminense / Postgraduate Program in Plant production. Av. Alberto Lamego, 2000. Parque California, 28035-200, Campos dos Goytacazes, RJ, Brazil
³Belo Monte Agricultural Family School, 29400-000, Mimoso do Sul – ES, Brazil
⁴Ibitirama family Agricola school, 29540-000, Ibitirama – ES, Brazil

Abstract:

Different tomato cultivars may present differentiated water needs, making it indispensable to study water demand. Thus, the objective of this work was to evaluate the influence of six water stresses in the soil on the extraction potential of macro and micronutrients in the aerial part of tomato in vegetative stage, cultivar  Dominador’ F1, under protected cultivation and drip. The  experiment was installed in a greenhouse with a randomized block design with four replications. The treatments consisted of six soil water stresses as indicative of the time of irrigation. The preset stresses were 20, 45, 70, 95, 120 and 145 kPa at 20 cm depth. At 140 days after transplanting, the variables evaluated were: the macro and micronutrient content of shoots. The results showed that to obtain higher levels of macro (P and S) and micronutrients (B and Cu) of the total aerial part of the ‘Dominador’ tomato plant F1, it was obtained at a voltage of 20 kPa, and its value was reduced linearly with the increase of the water tension in the soil.

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2144–2160 K. Spalvins and D. Blumberga
Analysis of Arabidopsis defensin-like genes and ovule development during fertilization and Fusarium infection
Abstract |

Analysis of Arabidopsis defensin-like genes and ovule development during fertilization and Fusarium infection

K. Spalvins* and D. Blumberga

Riga Technical University, Institute of Energy Systems and Environment, Azenes street 12/1, LV 1048, Riga, Latvia
*Correspondence: kriss.spalvins@rtu.lv

Abstract:

Defensins are small, highly stable antimicrobial peptides. Many defensin-like (DEFL) peptides found in flowering plant Arabidopsis thaliana are believed to have role in either natural immunity or cell-to-cell communication during fertilization. However, little is known about the DEFL peptides and their functions during these events. The goal of this work is to investigate the genes encoding selected DEFLs by observing their expression patterns during fertilization and Fusarium graminearum infection. According to the results 4 selected genes of interest (GOI) are downregulated after fertilization and infection and mock treatments are causing degradation and delay of development in treated ovules.

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