scholarly journals Properties of the Loess Sediments in Ostrava Region (Czech Republic) and Comparison with Some Other Loess Sediments

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Marian Marschalko ◽  
Işık Yilmaz ◽  
Lucie Fojtova ◽  
David Lamich ◽  
Martin Bednarik

This study deals with a methodical identification and evaluation of physical-mechanical properties of one genetic type of geological structure. This is represented by an engineering-geological zone of eolian sediments, which is regionally rather abundant. The paper contributes to a need to identify typical soil properties for widespread geological environments in a particular region and thus add to good engineering geologists and geotechnical engineers’ awareness in the region. Such information is much required as it permits comparing results of newly conducted engineering-geological investigations and research with the results characteristic for the region in question. It is vital for engineering geologists and geotechnical engineers to be sufficiently informed on the foundation soil properties of widespread geological environments because of professionalism and higher quality of their work results. Comparing other loess sediment studies worldwide it was discovered that the physical properties of the most abundant clays of low to medium plasticity, sandy clays, and sands as foundation soils vary as for the plasticity index, porosity, natural water content, and bulk density to a certain extent but not as significantly as once expected.

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Marian Marschalko ◽  
Işık Yilmaz ◽  
Lucie Fojtová ◽  
Karel Kubečka ◽  
Tomáš Bouchal ◽  
...  

The paper deals with the influence of soil genesis on the physical-mechanical properties. The presented case study was conducted in the region of the Ostrava Basin where there is a varied genetic composition of the Quaternary geological structure on the underlying Neogeneous sediments which are sediments of analogous granulometry but different genesis. In this study, 7827 soil samples of an eolian, fluvial, glacial, and deluvial origin and their laboratory analyses results were used. The study identified different values in certain cases, mostly in coarser-grained foundation soils, such as sandy loam S4 (MS) and clayey sand F4 (CS). The soils of the fluvial origin manifest different values than other genetic types. Next, based on regression analyses, dependence was proved neither on the deposition depth (depth of samples) nor from the point of view of the individual foundation soil classes or the genetic types. The contribution of the paper is to point at the influence of genesis on the foundation soil properties so that engineering geologists and geotechnicians pay more attention to the genesis during engineering-geological and geotechnical investigations.


2020 ◽  
Vol 15 (No. 2) ◽  
pp. 116-124
Author(s):  
Petra Bíla ◽  
Bořivoj Šarapatka ◽  
Ondřej Horňák ◽  
Jaroslava Novotná ◽  
Martin Brtnický

Soil erosion, especially water erosion, is one of the most widespread types of soil degradation, not only worldwide, but also within the Czech Republic, where it endangers more than a half of the agricultural land. In addition to farming, the landscape structure has a significant impact on soil erosion in the conditions under study, where, especially in the post-war period, the collectivisation of large-scale arable land was accompanied by the abolition of the associated landscape elements. The agricultural production area of South Moravia is one of the most endangered areas in the Czech Republic, therefore, it was selected for our research, whose main objective was to verify the sensitivity of the selected physical, chemical and biochemical characteristics to identify the changes in the soil properties in the erosion processes at the identified erosion areas. The testing was carried out within a period of 5 years in 60 locations with Chernozems with cultivated corn. To assess the quality of the soil properties, indicators of soil quality from the physical, chemical and biological – biochemical groups were selected. The results of the analyses and the subsequent statistical evaluation showed that the chemical characteristics, especially those related to the quantity and quality of the organic matter, were the most sensitive to the changes in the soil properties. From the biochemical indicators, some enzymes, particularly dehydrogenase and acid phosphatase, reacted sensitively. The physical characteristics were not significantly affected by the erosion processes.


2016 ◽  
Vol 8 (15) ◽  
pp. 47-54
Author(s):  
Haspiadi Haspiadi

The purpose of this research is to know the influence of pressure and use of conplast against mechanical properties which are a Modulus of Elasticity (MOE) and Modulus of Rupture (MOR) of plasterboard. The study is done because still low quality of plasterboard made from a mixture of ashes of oil-palm shell especially of the mechanical properties compared to the controls. The method of this reserach used variation of printed pressure and the addition of conplast. Test result is obtained that the highest value of Modulus of Elasticity (MOE) 90875.94 Kg/cm2, Modulus of Rupture (MOR) 61.16 Kg/cm2 and density values in generally good printed at the pressure 60 g/cm3 and the addition of conplast 25% as well as the composition of the ash of palm shell oil 40%: limestone 40%: cement 15%: fiber 5% and 300 mL of water. ABSTRAK Tujuan dari penelitian ini adalah untuk mengetahui pengaruh tekanan dan penggunaan conplast terhadap sifat mekanik yaitu kuat lentur dan keteguhan patah eternit berbahan dasar abu cangkang sawit. Penelitian ini dilakukan karena masi rendahnya mutu eternit berbahan campuran abu cangkang sawit dari bolier khususnya sifat mekanik dibandingkan dengan kontrol. Metode penelitian yang digunakan adalah dengan variasi tekanan cetak dan penambahan conplast. Hasil uji diperoleh bahwa kuat lentur tertinggi sebesar 90875,94 Kg/cm2 dan keteguhan patah sebesar 61,16 Kg/cm2, yang dicetak pada tekanan 60 g/cm3 dan penambahan conplast 25% dengan komposisi  abu cangkang sawit 40 %: kapur 40 % : semen 15 %: serat 5 % dan air 300 mL.Kata Kunci :  Abu cangkang sawit, conplast, kuat lentur, keteguhan patah.


Author(s):  
Milan Chmura

The education and development of university teachers have its justifcation and its importance is signifcant not only in the Czech Republic but also abroad. This study provides an analysis of further professional education of university teachers in the Czech Republic and in selected European countries. Subsequently, it presents an international project with participants from the Czech Republic, Ukraine, Slovakia and Poland, which, ultimately, plays a role in the improvement of the quality of higher education.


2011 ◽  
Vol 19 (4) ◽  
pp. 897-901 ◽  
Author(s):  
Xu CUI ◽  
Xiao-Dong WANG ◽  
Wen-Hua FAN ◽  
Jian-Ming WANG ◽  
Ke-Yong CUI

2013 ◽  
Vol 21 (7) ◽  
pp. 810-816
Author(s):  
Wen-Jun DONG ◽  
Pei-Zhi XU ◽  
Ren-Zhi ZHANG ◽  
Xu HUANG ◽  
Hua-Ping ZHENG ◽  
...  

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 354
Author(s):  
Tim Tofan ◽  
Rimantas Stonkus ◽  
Raimondas Jasevičius

The aim of this research is to investigate related effect of dyeability to linen textiles related to different printing parameters. The study investigated the change in color characteristics when printing on linen fabrics with an inkjet MIMAKI Tx400-1800D printer with pigmented TP 250 inks. The dependence of color reproduction on linen fabrics on the number of print head passes, number of ink layers to be coated, linen fabric density, and different types of linen fabric was investigated. All this affects the quality of print and its mechanical properties. The change in color characteristics on different types of linen fabrics was determined experimentally. We determine at which print settings the most accurate color reproduction can be achieved on different linen fabrics. The difference between the highest and the lowest possible number of head passages was investigated. The possibilities of reproducing different linen fabric colors were determined.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4329
Author(s):  
Atif H. Asghar ◽  
Ahmed Rida Galaly

An experimental study was performed on a low-density plasma discharge using two different configurations of the plasma cell cathode, namely, the one mesh system electrodes (OMSE) and the one mesh and three system electrodes (OMTSE), to determine the electrical characteristics of the plasma such as current–voltage characteristics, breakdown voltage (VB), Paschen curves, current density (J), cathode fall thickness (dc), and electron density of the treated sample. The influence of the electrical characteristics of the plasma fluid in the cathode fall region for different cathode configuration cells (OMSE and OMTSE) on the performance quality of a surgical gown was studied to determine surface modification, treatment efficiency, exposure time, wettability property, and mechanical properties. Over a very short exposure time, the treatment efficiency for the surgical gown surface of plasma over the mesh cathode at a distance equivalent to the cathode fall distance dc values of the OMTSE and for OMSE reached a maximum. The wettability property decreased from 90 to 40% for OMTSE over a 180 s exposure time and decreased from 90 to 10% for OMSE over a 160 s exposure time. The mechanisms of each stage of surgical gown treatment by plasma are described. In this study, the mechanical properties of the untreated and treated surgical gown samples such as the tensile strength and elongation percentage, ultimate tensile strength, yield strength, strain hardening, resilience, toughness, and fracture (breaking) point were studied. Plasma had a more positive effect on the mechanical properties of the OMSE reactor than those of the OMTSE reactor.


Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 847
Author(s):  
Anita Zapałowska ◽  
Natalia Matłok ◽  
Miłosz Zardzewiały ◽  
Tomasz Piechowiak ◽  
Maciej Balawejder

The aim of this research was to show the effect of the ozonation process on the quality of sea buckthorn (Hippophae rhamnoides L.). The quality of the ozonated berries of sea buckthorn was assessed. Prior to and after the ozone treatment, a number of parameters, including the mechanical properties, moisture content, microbial load, content of bioactive compounds, and composition of volatile compounds, were determined. The influence of the ozonation process on the composition of volatile compounds and mechanical properties was demonstrated. The ozonation had negligible impact on the weight and moisture of the samples immediately following the treatment. Significant differences in water content were recorded after 7 days of storage. It was shown that the highest dose of ozone (concentration and process time) amounting to 100 ppm for 30 min significantly reduced the water loss. The microbiological analyses showed the effect of ozone on the total count of aerobic bacteria, yeast, and mold. The applied process conditions resulted in the reduction of the number of aerobic bacteria colonies by 3 log cfu g−1 compared to the control (non-ozonated) sample, whereas the number of yeast and mold colonies decreased by 1 log cfu g−1 after the application of 100 ppm ozone gas for 30 min. As a consequence, ozone treatment enhanced the plant quality and extended plant’s storage life.


2007 ◽  
Vol 336-338 ◽  
pp. 1791-1792
Author(s):  
Hai Ping Cui ◽  
Jun Yan ◽  
Shi Guo Du ◽  
Xin Kang Du

Al2O3-Al2Cu3 multiphase coatings were prepared on the surface of steel by reactive flame spray. The binding strength, microhardness and abrasion quality of the coatings were measured and analyzed. The influence of the agglomerate size on the properties of the coatings was emphatically studied to choose suitable size range for Al-CuO reactive system. The results showed that coatings prepared by using –150∼+250 meshes agglomerates exhibited good mechanical properties.


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