Wyniki wyszukiwania

1

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Influence of the sand particle shape on particle size distribution measured by laser diffraction method

100%

Polakowski C., Sochan A., Bieganowski A., Ryzak M., Foldenyi R., Toth J.

International Agrophysics

|

2014

|

tom 28

|

nr 2

The aim of this paper was to show how the shape of sand particles affects the results of particle size distribution obtained by the laser diffraction method. On the basis of the results obtained one can conclude: the shape of the investigated particles influences particle size distribution obtained by the laser diffraction method. This phenomenon occurs in the sand fraction, as shown in our investigation. The importance of this effect depends on the type of the measured material and on the aim of the investigations. For most researchers in soil science and sedimentology who investigate sand fractions, this impact can be negligible. Further investigations with other soil and sediment fractions are needed.

2

Flow coefficient of the aggregates as a parameter characterizing the suitability of non-cohesive soils for earthworks

88%

Majer S.

Przegląd Naukowy. Inżynieria i Kształtowanie Środowiska

|

2020

|

tom 29

|

nr 3[89]

3

Laboratory assessment of permeability of sand and biopolymer mixtures

88%

Wiszniewski M., Skutnik Z., Cabalar A. F.

Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation

|

2013

|

tom 45

|

nr 2

This research presents a method of creating seepage barriers in a sandy soil using biopolymer additives (biosubstance), which consist of polysaccharides and water. Polysaccharides strongly interact with water to produce a viscous suspension. The paper aims to investigate the infl uence of a biosubstance employed in a highly permeable sandy soil. Amount of the biopolymer used in a sample were 0.5, 1.0 and 1.5%, by dry weight. The test results indicate that the hydraulic conductivity signifi cantly decrease with the amount of biosubstance added but only slightly increase when curing time gets longer. It is thought that such application, which is a relatively new soil improvement technique, could be used as a seepage barrier installation required to protect some geotechnical works including foundation, underground structures and waste disposals.

4

Some geomechanical properties of a biopolymer treated medium sand

88%

Wiszniewski M., Skutnik Z., Biliniak M., Cabalar A. F.

Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation

|

2017

|

tom 49

|

nr 3

5

A comparison of oxygen diffusion rates in sand moistened with water or PEG 20000 solution

88%

Hiller S., Dexter A. R.

International Agrophysics

|

1997

|

tom 11

|

nr 3

6

Plastic flow rule for sands with friction, dilation, density and stress state coupling

75%

Wojciechowski M.

Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation

|

2015

|

tom 47

|

nr 2

In this paper we propose a flow rule and failure criterion for sands in plane strain conditions based on Drucker-Prager formulation and enhanced with empirical Houlsby formula, which couples friction, dilation, density and stress state in the material. The resulting elasto-plastic, non-associated, shear hardening material model is implemented as a numerical procedure in the frame of finite element method and a simple compression example is presented. Because of the empirical nature of Houlsby formula, it is believed that results of numerical simulations will be more realistic both in deformation and shear strength estimation of sands.

7

Suction controlled triaxial testing of unsaturated medium sand and sandy clay

75%

Skutnik Z., Biliniak M.

Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation

|

2014

|

tom 46

|

nr 4

This paper presents the results of the triaxial tests performed on medium sand and sandy clay samples. The shear strength and deformation characteristics from consolidated drained (CD) tests performed in a controlled saturation state were determined. The study was conducted in a modern apparatus for triaxial testing of unsaturated samples. Test specimens with a diameter of 70 mm and height of 140 mm were prepared by compaction in a laboratory in a special form. The main aim of this study was to investigate the effect of matric suction on the shear strength and deformation characteristic of medium sand and sandy clay. The axis translation technique was used to apply matric suction to soil specimens.

8

Adsorption and desorption of boron on manganese oxide-coated sand as influenced by pH

75%

Wojcik P., Wojcik M.

Journal of Fruit and Ornamental Plant Research

|

1999

|

tom 07

|

nr 4

9

Assessment of chemical composition and sanitary state of sand in selected sandboxes in Krakow

63%

Jasiewicz C., Baran A., Antonkiewicz J.

Journal of Elementology

|

2009

|

tom 14

|

nr 1

79-89

The aim of the research was to assess the chemical composition and sanitary state of sandboxes in Krakow. Samples of sand were collected from 42 sandboxes located on playgrounds in housing estates and municipal (urban) parks. In the samples the following were determined: reaction, organic matter and the content of total and soluble forms of several elements. The sand in the analyzed sandboxes had highest content of Zn, while the concentrations of other metal appeared in the following decreasing order: > Pb > Cr > Ni > Cu > Cd (total forms) and Zn > Pb > Cu > Ni > Cr > Cd (soluble forms). The highest potential for ingesting heavy metals by humans due to accidental consumption of sand was found for Zn, followed by Pb > Cu > Ni > Cr > Cd. Children were at a higher risk of exposition to heavy metals than adults. On no occasion, the permissible limits of heavy metals for urbanized and built-up areas (group B) – set up by the regulation of the Minister for Environment on soil and earth quality – were exceeded. The same applies to the threshold levels of contaminants established for soils polluted by man-made sources. However, the sandboxes were found to be in poor sanitary conditions.

10

Differences of chemical components in beaches sediments with dissimilar anthropopressure

63%

Trojanowski J., Bigus K., Trojanowska C.

Baltic Coastal Zone. Journal of Ecology and Protection of the Coastline

|

2011

|

tom 15

The investigations of the chemical composition of sands were conducted on the beach in Ustka and Czołpino. The Ustka is a typical tourist town and Czołpino is located in the Slovinski National Park away from urban or rural areas. The beach sediments in Ustka contain much more organic matter, nitrogen and phosphorus compounds as well as calcium carbonate than analogous deposits in Czołpino. The effect of sea water was manifested in the high content of organic matter in places having permanent contact with sea water. The content of the organic matter increased together with with the depth of settlings in these places. However more organic matter in surface layers was observed in regions more distant from the sea, because penetration of organic matter into the sediments is possible during precipitation. The concentration of ammonia nitrogen in the analyzed beach deposits increased with depth, what probably results from the lower oxygen content in deeper layers. It was confirmed that organic matter in sands of the beach in Czołpino is of natural origin, while in Ustka it is primarily of anthropogenic origin.

11

Recovery of macrobenthic assemblages following experimental sand burial

63%

Yanez B., Carballo J. L., Olabarria C., Barron J. J.

Oceanologia

|

2008

|

tom 50

|

nr 3

391-420

Periodic inundation by sand is a very common feature of rocky coasts throughout the world. Even so, there have been few direct observations or experiments to investigate the role of sediments on intertidal rocky shores. We designed a field experiment in Mazatl´an Bay, Mexico, to test the initial impact and subsequent recovery of intertidal macrobenthic assemblages exposed to sand burial at two sites of varying wave exposure. Both sites supported different natural assemblages. Treatment plots for the addition of sediment and control plots (50×50 cm), separated by at least 1.5 m, were randomly placed across the mid-water tidal level. The initial response of the resident macrobenthos and the subsequent recolonization was monitored over a period of 95 days. The main effect of sediment deposition at both sites was mortality and removal of biota due to smothering. The recovery process was rapid and may in part have been the result of the mechanism by which the small, disturbed patches were recolonized. Most of the invertebrates colonized the patches as adults; several seaweeds exhibited vegetative growth as the major mechanism of colonization (e.g., Ulva lactuca Linnaeus, 1753, Amphiroa valonioides Yendo, 1902 and Chaetomorpha antennina (Borgensen) Kutzing, 1849). The rate of recovery varied between the sites, however. Recovery of species numbers proceeded quickly at the sheltered site (day 7), but took 95 days at the exposed site. In contrast, biomass reached control levels by day 45 at the sheltered site, but already by day 15 at the exposed site. By day 95, the assemblages recovered to 83.5% and 81% similarity with the controls at the sheltered and exposed sites respectively. Although differences in wave exposure could be very important in determining the different patterns of recovery at both sites, other biological processes may also play an important part.

12

Antibiotic resistance of fecal coliform bacteria inhabiting sea water and sand of marine recreation beach in the southern Baltic Sea

63%

Mudryk Z. J., Perlinski P., Robak D.

Baltic Coastal Zone. Journal of Ecology and Protection of the Coastline

|

2016

|

tom 20

The results of the present study showed variability in resistance of FC bacteria isolated from beach sand and sea water against tested antibiotics. Enteric bacteria were the most resistant to clindamycin and penicillin while the most sensitive to ciprofloxacin, gentamycin, neomycin, rifampicin and streptomycin. Fecal coliform bacteria inhabiting sand were more resistant to nearly all tested antibiotics compared to bacteria isolated from sea water. The majority of bacteria inhabiting sea water and sand of the studied beach were resistant to only 1-4 antibiotics out of the 12 antibiotics tested. Fecal coliform bacteria isolated from Ustka beach were the most resistant to β-lactam and lincosamide antibiotics, while the most susceptible to aminoglycosides.

13

Preliminary researches on sand accumulation in the alimentary canal of recreational riding horses

63%

Ciesla A., Ignor J., Przybylowicz N., Pikula I.

Acta Scientiarum Polonorum. Zootechnica

|

2011

|

tom 10

|

nr 2

Six warm-blooded horses in the age of 6 till 16, were researched. The horses were divided into two groups: experimental and testing (each per 3 horses). In the first stage the trial was taken up to estimate the grade (rank) of sand accumulation in the alimentary canal of all horses with using the floatation test. In the second stage the experimental group with the given foragegot the supplement of Plantago Psyllium seeds in the amount of 210 g per horse per day during 7 days. The researches revealed that preventive supplement of Plantago Psyllium seeds three times increases the amount of sand excreted from the alimentary canal. So using the supplement of Plantago Psyllium seeds can prevent the excessive of sand concentration in horses alimentary canal and this way decreases the risk of occurring the intestinal colic diseases – in the matter.

14

Applications of permeability, oedometer and direct shear tests to the sand mixed with waste tire crumb

63%

Wiszniewski M., Cabalar A. F.

Acta Scientiarum Polonorum. Architectura

|

2016

|

tom 15

|

nr 1

The amount of the used waste rubbers in the world has been increasing every year, and their utilization, become a major environmental problem worldwide. The present experimental work has been performed to investigate the influence of rubber inclusion on the behavior of a sand. Geotechnical properties of the sand, and sand with tire crumb at various ratios mixtures (0, 2.5, 7.5, and 15%) were investigated through a series of mechanical tests, which are sieving, permeability, direct shear and consolidation. From the results of conducted tests, it is revealed that the addition of tire crumb grains increased both the permeability and the compressional characteristics of the sand. Besides, in this work, inter-granular void ratio (es) was employed as an alternative parameter to express the compressive response of sand-tire crumb mixtures. It is seen that intergranular void ratio concept is a good indicator for understanding the behavior of sands with waste tire crumb.

15

Increase of coupling characteristics and profitability of the locomotive modernization of system of supply of sand

63%

Kovtanets M., Gorbunov N., Prosvirova O., Sosnovenko S., Astakhov V.

Teka Komisji Motoryzacji i Energetyki Rolnictwa

|

2012

|

tom 12

|

nr 4

16

Pine forests of Zn-Pb post-mining areas of Southern Poland

63%

Grodzinska K., Szarek-Lukaszewska G., Godzik B.

Polish Botanical Journal

|

2010

|

tom 55

|

nr 1

229-237

17

Scanning electron microscopy investigation of bacterial colonization of marine beach sand grains

63%

Mudryk Z. J., Podgorska B.

Baltic Coastal Zone. Journal of Ecology and Protection of the Coastline

|

2006

|

tom 10

Scanning electron microscopy was employed for the investigation of bacteria living on sand grains in a sandy marine beach in the Gulf of Gdansk (southern Baltic Sea). Bacteria colonize the sand grains; individual topography and shape of the grains were decisive for the colonization. Grains of diverse topography characterised by a great irregularity of shape were preferred, and protected surface sites were favoured. Many of the attached bacteria were found to produce polymer secretions; entire colonies attached by means of polymer nets were observed. A significant morphological diversity of bacteria in the vertical profile of the beach was determined. Bacteria inhabiting the sand grains showed the ability to reproduces.

18

The fungi present in the sand and soil of recreational areas as possible factors of fungal infection among children: hydrolytic enzymes - a determinant of pathogenicity

63%

Kurnatowski P., Wojcik A., Blaszkowska J., Goralska K.

Annals of Parasitology

|

2016

|

tom 62

|

nr Suppl.

19

Effects of stabilization with cement on mechanical properties of cohesive soil – sandy-silty clay

63%

Sas W., Gluchowski A.

Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation

|

2013

|

tom 45

|

nr 2

Ground improvement as a result of stabilization with cement has its impact on soft soils such as sandy clay in engineering constructions. Stabilized soils are also used in foundation design, where improvement of mechanical properties is needed. Because of these reasons, knowledge of physical and mechanical properties is needed. The relationship stress – strain of soils stabilized with cement is often unclear and strength characteristics need to be clear. In this paper results of physical and mechanical properties soil stabilized with cement are presented.

20

Water retention characteristics of peat and sand mixtures

63%

Walczak R., Rovdan E., Witkowska-Walczak B.

International Agrophysics

|

2002

|

tom 16

|

nr 2

Ograniczanie wyników

Influence of the sand particle shape on particle size distribution measured by laser diffraction method

Flow coefficient of the aggregates as a parameter characterizing the suitability of non-cohesive soils for earthworks

Laboratory assessment of permeability of sand and biopolymer mixtures

Some geomechanical properties of a biopolymer treated medium sand

A comparison of oxygen diffusion rates in sand moistened with water or PEG 20000 solution

Plastic flow rule for sands with friction, dilation, density and stress state coupling

Suction controlled triaxial testing of unsaturated medium sand and sandy clay

Adsorption and desorption of boron on manganese oxide-coated sand as influenced by pH

Assessment of chemical composition and sanitary state of sand in selected sandboxes in Krakow

Differences of chemical components in beaches sediments with dissimilar anthropopressure

Recovery of macrobenthic assemblages following experimental sand burial

Antibiotic resistance of fecal coliform bacteria inhabiting sea water and sand of marine recreation beach in the southern Baltic Sea

Preliminary researches on sand accumulation in the alimentary canal of recreational riding horses

Applications of permeability, oedometer and direct shear tests to the sand mixed with waste tire crumb

Increase of coupling characteristics and profitability of the locomotive modernization of system of supply of sand

Pine forests of Zn-Pb post-mining areas of Southern Poland

Scanning electron microscopy investigation of bacterial colonization of marine beach sand grains

The fungi present in the sand and soil of recreational areas as possible factors of fungal infection among children: hydrolytic enzymes - a determinant of pathogenicity

Effects of stabilization with cement on mechanical properties of cohesive soil – sandy-silty clay

Water retention characteristics of peat and sand mixtures