Browse

You are looking at 1 - 10 of 2,706 items for :

  • Architecture and Architectonics x
Clear All

Abstract

This study intends to examine the soil behaviour in the case of finite thickness, represented by the hard layer under a soft layer of soil. A further aim is to define load-bearing capacity parameters (n and k). The experimental work is carried out under laboratory conditions by using hydraulic bevameter to apply the load. A circular plate with a diameter of 100 mm is used to push down the load over the targeted area with a penetration rate of about 9 cm/min for sinkage plates. The study was conducted in a soil bin (length of 200 cm, width of 100 cm and variable thickness) using a sandy loam soil. First, the study has been done with loose soil with a thickness of 11 cm, which maintained with 10% moisture content and initial density of 1.190 g/cm3. After that, a two thickness of 6 and 18 cm with 8% moisture content and initial soil density of 1.375 g/cm3 were tested to explain the effect of thickness. In each test, the bevameter plate was loaded at multiple locations, the result showed the soil was near uniform. The result suggests that it is not easy to obtain one equation for the load bearing capacity because the layer near to the surface behaves like soil with infinite thickness and the deeper layer like soil with finite thickness.

Open access

Shewanella putrefaciens supernatant was found to increase the virulence factors of Vibrio parahaemolyticus by efficiently degrading its acylhomoserine lactone (AHL). To further reveal the regulation mechanism and its key degrading enzyme, a potential AHL-degrading enzyme acylase (Aac) from S. putrefaciens was cloned, and the influences of temperature, pH, protein modifiers, and metals on Aac were tested. Aac was significantly influenced by temperature and pH, and exhibited the highest AHL-degrading activity at temperatures of 37 °C and pH of 8. Mg2+ and Fe2+ can further increase the AHL-degrading activity. 10 mM EDTA inhibited its activity possibly by chelating the co-factors (metals) required for Aac activity. Tryptophan and arginine were identified as key components for Aac activity that are critical to its AHL-degrading activity. This study provides useful information on Aac and for V. parahaemolyticus control.

Restricted access

During the production of natural gas one of the major problems is the formation of hydrate crystals in the pipeline. The forming hydrate crystals can form hydrate plugs in the pipeline. The hydrate plugs lengthen production outages and result in financial losses for the producer, because the removal of the plugs is a time consuming procedure. One of the solutions used to prevent hydrate formation is the injection of modern compositions to the gas flow. The modern compositions help to dehydrate the gas, thus, the size of hydrate crystals does not increase. The substances, used in low concentrations, have to be locally injected, at the gas well sites. Inhibitor dosing depends on the amount of gas hydrate present. In the article a neural network based predictive detection solution is presented, which uses four factors.

Open access

The aim of this work was to evaluate the antioxidant and antibacterial activities of two marine algae, Cystoseira mediterranea and Padina pavonica, extracts. Total phenols (TPC), carotenoids, and phlorotannins contents of the extracts obtained by four extraction solvents were determined and compared. The highest TPC content was observed for aqueous extract of C. mediterranea with 37.09±0.46 mg GAE/g DE followed by ethanol extract of P. pavonica (24.28 ±0.99 mg GAE/g DE), which showed the highest phlorotannins content (1.18±0.18 mg PE/g DE), while its methanol extract held carotenoids content of 66.96 ±4.78 μg g–1 DE. Ethanol extract of C. mediterranea exhibited the best antioxidant activity with an EC50 of 58.3 ±1.16 μg ml . The antibacterial activity screening against MRSA and E. coli showed that ethanol extract of C. mediterranea towards a Methicillin resistant Staphyloccocus aureus (20.33±0.28 mm) and E. coli (15.66±0.57 mm) was more efficient with MICs about 80 mg ml–1 and 20 mg ml–1, respectively. Ethanol extract of C. mediterranea seems to have the highest potential for use in food industries.

Restricted access
Pollack Periodica
Authors: Richard Honti, Ján Erdélyi and Alojz Kopáčik

Nowadays huge datasets can be collected in a relatively short time. After capturing these data sets the next step is their processing. Automation of the processing steps can contribute to efficiency increase, to reduction of the time needed for processing, and to reduction of interactions of the user. The paper brings a short review of the most reliable methods for sphere segmentation. An innovative algorithm for automated detection of spheres and for estimating their parameters from 3D point clouds is introduced. The algorithm proposed was tested on complex point clouds. In the last part of the paper, the implementation of the algorithm proposed to a standalone application is described.

Restricted access

In this study the competitiveness of Hungarian enterprises was analyzed, because relatively little research has been conducted to investigate small enterprises. More specifically, the paper examines to what extent the use of online solutions gives companies a competitive advantage. Nearly 800 companies were involved in the research, for which a new methodology was used. It is built on a multi-step model, which is based on mathematical calculations. From the result of a questionnaire survey, variables were generated to create a number of competitiveness pillars, which were used to determine the final competitiveness index of each company. The research was carried out at the Faculty of Business and Economics, University of Pécs. Scientists form the Faculty of Engineering and Information Technology, University of Pécs were involved in the online analysis of the companies, the results of which were integrated into the research findings. The analysis shows that the companies, which do not use online solutions during their operations can be competitive but generally those present in the online space are more competitive, and use more sophisticated solutions in their business processes, which has a positive effect on several functions of the company. Overall these companies have a higher competitiveness index, which confirms that it is worth using online solutions for companies.

Open access
Acta Alimentaria
Authors: S. Hu, H. Shu, J.L. Yuan, J.Y. Gao, P.Y. Mu, C.Z. Ren, W. Sang, L.C. Guo and H.B. Chen

The objective of this study was to evaluate the effect of wheat–oat flour ratio on the physical properties and β-glucan characteristics of extrudates. Results showed that increasing the wheat–oat flour ratio resulted in a decrease in the water solubility index (r2=0.8567) and hardness (r2=0.9316), whereas the expansion ratio (r2=0.9307) and water absorption index (r2=0.9061) increased. Wheat flour generally caused an increase in L values from 57.81 to 62.94 providing bright samples. Few cells were observed at high wheat–oat flour ratios under a scanning electron microscope, and a smooth surface was noted. Meanwhile, the total (r2=0.9867) and soluble (r2=0.9848) β-glucan contents were inversely proportional to the wheat–oat flour ratio. Extrudates with added wheat flour had a high molecular weight, but wheat flour had no significant (P<0.05) effect on the viscosity of β-glucan extracts. Conclusively, incorporation of wheat flour at a wheat–oat flour ratio of 2.33 provides ready-to-eat food based on whole oat flour, on account of improving the texture and providing sufficient β-glucan contents (0.806 g/100 g) without significantly affecting β-glucan viscosity.

Restricted access

Honey is the most important bee product. There are many secondary metabolites, carbohydrates, enzymes, and vitamins in honey, thus, honey has antimicrobial activity. In this study, in vitro antimicrobial activity of forty-two honey and eight propolis ethanolic extracts (PEE) were investigated against 16 microorganisms. Total phenolic content ranged between 20.00–124.10 mg GAE/100 g and 103–232 mg GAE/g for honey and raw propolis samples, respectively. Pine and oak honeydew honeys had higher antimicrobial activity than four different grades of Manuka Honeys up to 18 mm minimum inhibition zone diameters. The ethanolic propolis extracts showed much higher antimicrobial activity than the honey samples. Fungi species were inhibited by the propolis samples. Helicobacter pylorii (H. pylorii) was the most sensitive, whereas Streptococcus agalactiae was the most resistant bacteria among the studied microorganisms. Brazilian and Zonguldak propolis had the closest antimicrobial activity to ampicillin, streptomycin, and fluconazole. It can be concluded that both honey and propolis could be used in preservative and complementary medicine.

Open access
Pollack Periodica
Authors: Peter Michalek, Jakub Kralovanec and Jan Bujnak

Reactive powder concretes are a set of ultrahigh-strength concrete reinforced with fibers. Their compressive strength is greater than 100 MPa. For assuring connection of steel beams and a concrete slab, steel stud connectors are used. The investigation of that kind of shear connection efficiency, in the case of this higher strength concrete deck using standard push-out test specimens has been executed. The experimental results are presented in the paper.

Restricted access

This study investigated the chemical properties of Durio zibethinus (Durian) in Malaysia. The cultivars included in the present study were D101, D197, and Kampung. A wide range of chemical properties such as proximate nutritional content, minerals, total phenolic content was analysed using established analytical methods. The antioxidant capacity in term of free radical scavenging activity was determined using colorimetric assay, whereas metabolite profiles of samples were analysed by hyphenated high throughput tool like GC-MS. The results showed that D197 durian had the highest content of ash, protein, fat, and carbohydrate, but the lowest moisture level. Potassium was found to be the highest mineral (8.68–11.36 mg g–1), followed by sodium (3.2–7.6 mg g–1), magnesium (0.86–1.88 mg g–1), and calcium (2.74–3.80 mg g–1) in the tested cultivars. The major sulphur containing compounds (% relative peak area) such as hydrogen sulphide (5.0–8.3%), methanethiol (0.5–1.0%), ethanethiol (20.7–35.0%), 1-propanethiol (2.7– 9.5%), and diethyl disulphide (0.6–1.9%), and esters, especially ethyl 2-methylbutanoate (10.0–15.0%), methyl 2-methylbutanoate (1.0%), and propyl 2-methylbutanoate (1.5%) were detected when fresh samples were heated in headspace GC-MS. However, those compounds evaporated during ultrasound assisted extraction and oven drying even at 40 °C.

Restricted access