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Petroczki K.,St Istvan University | Fenyvesi L.,Hungarian Institute of Agricultural Engineering
Computers and Electronics in Agriculture | Year: 2014

Since the construction of a static and dynamic compressive testing instrument for examining biological materials, particularly fruits and tubercular roots, the need has arisen for the construction of a computer-controlled instrument that can bridge the gap between static and dynamic investigations in this field. The main utilisation possibilities of this instrument are demonstrated some measurement results with apple. The recently developed, easy-to-use instrument presented herein is suitable for serial measurements. In its present implementation, this instrument is capable of performing compressive testing with loading sticks of typical size with constant, linear slope and cosine force-time functions in single or cyclic mode. The force is generated by a PC-controlled servo system, and the deformation is measured by a laser sensor. The excitation force is 0-15. N within 1% FS accuracy in 0-300. Hz frequency range. Deformation measuring range is 10. mm with 12. μm resolution. The system contains a PC-based data logger. © 2013 Elsevier B.V. Source

Pek Z.,Szent Istvan University | Daood H.,Central Food Research Institute | Lugasi A.,National Institute for Food and Nutrition Science | Fenyvesi L.,Hungarian Institute of Agricultural Engineering | Helyes L.,Szent Istvan University
Acta Alimentaria | Year: 2014

Quantification of red pigment content of fruits using destructive techniques is expensive and it enables only the analysis of batches but not of individual items. This study examined the feasibility of using non-destructive, spectrophotometric method to predict one of the most valuable internal quality indices, lycopene, in individual tomato fruits. An open field experiment was conducted to study the effect of irrigation and potassium supplementation on the yield and lycopene content of processed tomato fruit. Three different treatments (regularly irrigated RI, irrigation cut-off 30 days before harvest CO, and rainfed RF unirrigated control) and two different potassium fertilisations (P) were applied. Regular irrigation significantly decreased the lycopene content of tomato fruits. The CO treatment resulted in the highest total lycopene without potassium supplementation. Potassium supplementation, given at the time before fruit maturity, significantly increased the lycopene concentration of cultivar Brigade independently of irrigation. The closest correlation was at 700 nm2=0.38 and R2=0.45, between reflectance and the (all-E)-lycopene and the (9Z)+(13Z)-lycopene isomers, respectively. Source

Toldi O.,Hungarian Institute of Agricultural Engineering | Tuba Z.,Szent Istvan University | Scott P.,University of Sussex
Romanian Biotechnological Letters | Year: 2010

A majority of plants possess stages in their life cycle at which specific tissues, mainly components of reproductive organs (mature pollen, seed) and dormant buds, can survive severe water loss. What is remarkable about resurrection plants is the ability of vegetative tissues (root, shoot, stem, leaves) to tolerate dehydration of the tissues and then return as functional units on rehydration. This phenomenon made resurrection plants exciting targets for molecular analysis of the poikilohydric ability and drought tolerance. Large-scale isolation of drought stress associated genes with unknown biological roles requires thorough functional analysis. Despite of the genetic and physiological complexity of desiccation tolerance, there are already examples where outcomes of targeted studies in resurrection plants are going to be directly utilized to engineer crop plants genetically. Here we show that conventional genetic transformation techniques, via in vitro plant regeneration systems, still represent an unavoidable part of the high-throughput technology chain of molecular breeding. © 2010 University of Bucharest. Source

Oldal I.,Szent Istvan University | Keppler I.,Szent Istvan University | Csizmadia B.,Szent Istvan University | Fenyvesi L.,Hungarian Institute of Agricultural Engineering
Advanced Powder Technology | Year: 2012

Engineers working on the field of agriculture, food- or pharmaceutical industry or in the architecture frequently meet problems arising from the special properties of granular assemblies. Storing large amount of particulate raw materials is mostly made by using large containers, called silos. The design of such large silos is far not an easy problem. The outflow properties are one of the most important parameters of silo design. The constant discharge rate of silos differs from the discharge rate of containers filled with liquids. In case of fluids, the flowing velocity and discharge rate changes with fluid level. In case of granular materials, the velocity is constant (independent of the filling level of silo). There are methods used for the determination of silo discharge rate, but these are mostly experimental without physical explanation of the phenomenon. In this paper we demonstrate that the constant discharge rate is caused by the formation and collapse of arches in the bin. Based on this assumption, we derive an equation for determining the discharge rate. Using the same arching hypothesis we derive the equations describing the velocity distribution at silo outlets. The usability of our new approach is demonstrated by experimental investigations. © 2011 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved. Source

Gulyas Z.,Hungarian Institute of Agricultural Engineering | Fenyvesi L.,Hungarian Institute of Agricultural Engineering | Szoboszlay S.,Szent Istvan University
Turkish Journal of Agriculture and Forestry | Year: 2012

The objectives of this research were to inspect the drop production of a twin fluid system with the Floodjet TK SS 10 042 deflector nozzle and to identify the drift of the droplets produced by the nozzle in a wind tunnel when using the nozzle with the individual settings provided by the company that enlisted our institute to do the described research task. The results of the inspection of drop production, done using a particle sizer, showed that the values of volume diameter Dv10 were low, the percentage of drops smaller than 100 μm in size was considerable, and the drop sizes varied widely in each setting. It was concluded that the risk of drift and, therefore, the risk of placing an unnecessary load on the environment existed when using the nozzle with the given settings. The application of the nozzle that was tested may cause problems in various aspects of practical spraying techniques. Based on the results of the drift measurements performed in a wind tunnel, the material deposition reported as relative coverage decreased significantly only when the recommended settings were changed at wind velocities of 2.0 m s-1 and 4.0 m s-1. At wind velocities of 4.0 m s-1 and 6.0 m s-1, detectable (>=1%) relative coverage values were recorded for each setting, even at the measurement limit. It was concluded that the inspected twin fluid system with the Floodjet TK SS 10 042 deflector nozzle does not provide the expected decrease in drift when using the given settings at wind velocities of 4.0 m s-1 and 6.0 m s-1. © TÜBITAK. Source

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