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Open access

Ildikó Szedljak, Viktória Tóth, Judit Tormási, Anikó Kovács, László Somogyi, László Sipos and Gabriella Kiskó

Abstract

In Hungary, dried pasta products are very popular amongst all groups of society. In recent years the demand for not only dried pasta made from hen eggs (Gallus gallus domesticus) but from alternative types of ingredients has increased. However, according to the literature the chemical and microbiological characteristics of this type of pasta have yet to be studied in depth. The effects of the use of quail eggs and heat treatments at different temperatures were studied by chemical and microbiological measurements. The activity of oxidative enzymes and nutritional characteristics (water-soluble total polyphenol content, water-soluble antioxidant capacity, peroxidase enzymatic activity, water-soluble protein content and yellow pigment content) was tested during our experiments. The data were evaluated by relevant statistical methods. Significant differences were found both between heat treatments and between the egg content of the dried pasta samples. The peroxidase enzymatic activity and yellow pigment content increased with temperature. However, the usage of quail eggs provides a higher water-soluble protein content and water-soluble antioxidant capacity. The presence of microorganisms is decreased by increasing the drying temperature. The number of all the examined microorganisms was within limits.

Open access

Réka Czinkóczky and Áron Németh

Abstract

Stevia rebaudiana Bertoni is a small, perennial and herbaceous shrub which originated in Paraguay (South America). Stevia rebaudiana is not native to Hungary but its cultivation and consumption may have many benefits, e.g. to reduce blood pressure and as a non-caloric sweetener. Steviol glycosides, mostly stevioside and rebaudioside A, located in the leaves are about 200–300 times sweeter than sucrose. S. rebaudina cultivation in Hungary would offer many opportunities in healthcare and the sweet industry. With the aim of achieving good green biomass yields, the effect of MACC4 autotrophic and heterotrophic algae strains was investigated by testing them as both leaf and soil fertilizers in the soil of Stevia rebaudiana seedlings and in its aqueous rooting experiments. In one of the later set up, the formation of roots was improved by combining the application of red light and algae treatment.

Open access

Farid Ullah, Fahim Al-Neshawy and Jouni Punkki

Abstract

Concrete is often sensitive to cracking during the hardening process, and these cracks could be the result of early-age shrinkage. One method to reduce shrinkage is to add different types of fibres to concrete. The aim of this study was to study the effects of different types of fibres on the early-age autogenous shrinkage of concrete. Three different types of fibre materials were used in the research. A “Schleibinger Bending-drain” test setup was used to record early-age autogenous shrinkage of fresh concrete immediately after mixing. The results show that, a fibre dosage of 0.38% by volume was found to be effective in reducing the effects of early-age autogenous shrinkage of concrete.

Open access

Grobelny Pawel, Legutko Stanislaw and Lukasz Furmanski

Abstract

The paper presents the possibilities of additive manufacturing of the selected alloy, Inconel, for production of ready-made elements. The results of surface topography examination of the material manufactured with the use of the device 557 RPMI working in the LDT technology (LDT = Laser Deposition Technology) have been compared to those of thecold drawn material. The surfacejust after manufacturing inthese two technologies has been compared to the one after machining by means of variable machining parameters. The surface roughness parameter, Sskis positive for all the surfaces of thesamplemade by the traditional technology, regardless of the feed. This means that most of the material is located close to the valleys. The surfaces are characterised by right-hand side asymmetry. In all the surfaces of the sample made by the additive technology, regardless of the feed value, the surface roughness parameter, Ssk, is negative, which means that most of the material is located close to the peaks.

Open access

Ádám Wirnhardt and Tamás Varga

Abstract

In polymer technologies, various particle shapes and size distributions can be found. One of these are heterodisperse polymer beads. The capabilities of polymer swelling can be used in industries, e.g in the production of ion-exchange resins, to intensify specific technological steps such as sulphonation in the manufacturing process of ion-exchange resins. According to the literature different approaches can be used to create models for describing the behavior of disperse systems, of which the simplest models are the particle size distribution models for a given state of the solid phase. The aim of our examination was to compare and evaluate these simple models in terms of modeling polymer swelling. Hence, most of these models examine how each of the investigated models can be applied to approximately describe growth in a heterodisperse polymer system and how the identified model parameters in each time step could be interpreted. All the models were fitted to generate particle size distributions based on a swelling rate constant. The swelling of a styrene divinylbenzene-based copolymer was chosen as the basis of our examination. A model is proposed that is capable of describing the changes in the size of beads over time in this system.

Open access

Vinod Dhaygude, Anita Soós, Ildikó Zeke and László Somogyi

Abstract

The objective of this work was to compare the physical and thermal characteristics of two coconut oils and their blends which were observed by the results of differential scanning calorimetry (DSC) and pulsed nuclear magnetic resonance (pNMR). Fat blends composed of different ratios (fully hydrogenated coconut oil / non-hydrogenated coconut oil: 25/75, 50/50 and 75/25) were prepared and examined for solid fat content. The solid fat content of samples was determined as a function of temperature by pNMR. The DSC technique determines the solid fat index by measuring the heat of fusion successively at different temperatures. DSC calculates the actual content of solids in fat samples and how it changes throughout the duration of heating or cooling. A characteristic curve is constructed by the correlation of enthalpies. Based on our results, it is clear that both DSC and pNMR techniques provide very practical and useful information on the solid fat content of fats. DSC is dynamic and pNMR is static. A difference in the values of the solid fat indexes of samples was observed which may be due to a fundamental difference between the two techniques. These data can be used by food manufacturers to optimize processing conditions for modified coconut oil and food products fortified with coconut oil.

Open access

Zoltán Lukács and Tamás Kristóf

Abstract

It has been known for a long time that oilfield chemicals used for different purposes (corrosion and scale inhibitors, scavengers, biocides, etc.) can modify the efficiency of each other. These cross-effects can exhibit adverse or beneficial impacts and may modify the overall corrosiveness of the medium to a great extent. However, there is no standard procedure in order to evaluate the cross-effects, i.e. the extent to which the effect of one of the chemicals is modified by the addition of another. The 2N Design of Experiment (DoE) method provides a robust and simple statistical way to evaluate the change in efficiency of oilfield chemicals owing to the addition of other additives. The 2N DoE method can also be applied to other systems. In the present work the effects and cross-effects in systems consisting of a corrosion inhibitor, as well as an oxygen and a hydrogen sulphide scavenger are investigated and successfully demonstrated in a typical oilfield corrosion system with electrochemical corrosion monitoring methods.

Open access

Jukka Lahdensivu, Pirkko Kekäläinen and Alina Lahdensivu

Abstract

Even though natural phenomena do not abide to borders, Finland has traditionally been considered an alkali-silica reaction (ASR) free country. This is due to exceptional quality of the mostly course crystalline igneous rocks. However, during the last few years dozens of cases of ASR have been reported. The scope of this study was to study the occurrence of ASR, and to find out the initiation time of the reaction in resent investigations of Finnish concrete structures. ASR is found occurring all over Finland. The reacting aggregates consist of rock types, which are considered relatively stable or low reacting in literature.

Open access

Ferenc Haraszti

Abstract

The traditional inspection of fittings used in the electrical industry is a cumbersome, dangerous process in terms of safety and operation. However, with the spread of thermography, these tests can be performed simpler, faster, and more safely through electrical connections. This article presents the possibilities, measurement difficulties and the advantages of thermography analysis [1-2].

Open access

Anna Maloveczky and Ambrus Karai

Abstract

Resistance welding has long been successfully used in the automotive industry, but nowadays, there are even more advanced technologies, such as laser beam welding, which is a much faster, more economical and flexible technology. During our work, we have mapped the possibility of replacing resistance welding with laser beam welding. Furthermore, we have found a solution to the problems occurring during laser beam welding. The biggest challenge in laser beam technology is that the zinc coating on the steel plates (required to prevent corrosion) evaporates during welding, resulting in pores, and leading to a significant reduction in weld strength. We have solved that by using spacer sheets, which allow the zinc vapour to escape from the keyhole.