scholarly journals Determination of Water Retention Properties of Silty Sands by Means of Combined Commercial Techniques

Geosciences ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 315
Author(s):  
Elisa Ponzoni ◽  
Alessandra Nocilla ◽  
Cristina Jommi
Keyword(s):  
Water Retention ◽  
Soil Strength ◽  
Recent Increase ◽  
A Priority ◽  
The Stability ◽  
Water Retention Properties ◽  
The Impact ◽  
Different Origin

A recent increase in frequency and severity of exceptional climatic events is of concern for the stability of natural and artificial slopes. These undergo continuous evaporation and infiltration cycles, which change the suction distribution and trigger shrinkage, swelling, cracking, and surficial erosion, overall decreasing the soil strength. To assess the impact of these climatic stresses, the determination of water retention properties is a priority. Although advanced techniques have been proposed in the last few decades to this end, simpler commercially available techniques allow collecting data for a larger number of samples in a shorter time, thus enabling a basic description of the water retention properties for a larger database of soils. Data on two silty sands, coming from very different climatic environments in Europe, were collected with a combination of two simple commercial devices, and the results were modelled with a van Genuchten’s law. The fitted parameters were found to correlate well with the amount of fines, irrespective of the different origin and composition of the two soils. Eventually, the limitation of the approach is discussed based on the results of cyclic drying–wetting tests.

scholarly journals Analysis of Stability Factors of Roadway Roof and Determination of Unsupported Roof Distance

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Sen Yang ◽  
Xinzhu Hua ◽  
Xiao Liu ◽  
Chen Li
Keyword(s):  
Influencing Factors ◽  
Geological Conditions ◽  
Mine Roadway ◽  
Flac 3D ◽  
Roof Stability ◽  
Analysis Of Stability ◽  
The Stability ◽  
The Impact ◽  
The Relationship

To determine the impact of influencing factors on unsupported roof stability in coal mine roadway, a mechanical model of the unsupported roof was built. FLAC 3D numerical simulation was utilized to study the stability of the unsupported roof under the influence of the depth of the roadway, the thickness of the roof, and the unsupported-support distance. In view of the key influencing factors, the geological conditions of the site, and the relationship between the tensile stress and tensile strength of the unsupported roof, the maximum unsupported roof distance during roadway excavation was determined. Considering the surplus safety factor of the unsupported roof, the reasonable unsupported roof distance during the excavation of roadway 150802 was finally determined to be 2.08 m. The comprehensive roadway excavation speed increased by 62.7%, achieving a monthly progress over 500 m.

Human Capital of the Enterprise in the Context of System Economy

2020 ◽  
pp. 24-38
Author(s):  
Dmitry A. Zhdanov
Keyword(s):  
Human Capital ◽  
Sustainable Growth ◽  
Key Factors ◽  
The Status ◽  
Environmental Process ◽  
Ongoing Development ◽  
The Stability ◽  
The Impact ◽  
A Company

One of the key factors that determine the success of the company and ensure its ongoing development, adaptation to the requirements of the digital economy, is the human capital (HC) of the enterprise. In this regard, the purpose of the study is designated as identifying ways to support the integral and sustainable growth of a company based on the development of its human capital. Since an enterprise is an open socio-economic system, the methodological basis of the work is the systems economic theory, which made it possible to present the company's activities as the interaction of object, environmental, process and project systems. Based on this concept and taking into account the objectives traditionally pursued by the company, four basic functional complexes have been identified that ensure the stability and reproductive capabilities of the enterprise, the challenges that need to be overcome within such capabilities were identified, the requirements for the knowledge, skills and abilities of personnel were established. Comparison of the human resources of the enterprise and the features of the corporate tasks solved with their help made it possible to group the elements of the company's HC in a new way – depending on the impact on the noted basic subsystems that determine the integrity of the company. This systematization demonstrated the interconnection of individual elements of the enterprise's HC and the performance of the corresponding complexes. Thus, the probable personnel reasons for the lag in certain areas of the company's activity and the possibilities of their reorganization by targeted impact on the required elements of the HC were identified. Since the implementation of the proposed approach requires the determination of the status of the corporate HC, and the reliability of such a procedure traditionally raises criticism due to the objective difficulties of measurement, the article proposes a methodology to streamline the process of assessing the state of the parameters under study. The methodology is based on the ranking of HC indicators depending on the accuracy of displaying the parameters of the object. The proposed approach made it possible to determine the tools for monitoring the selected categories of human capital, ways to step them up and remedy the situation.

scholarly journals Humidity interaction of lichens under astrobiological aspects: the impact of UVC exposure on their water retention properties

2015 ◽  
Vol 14 (3) ◽  
pp. 445-456 ◽  
Author(s):  
J. Jänchen ◽  
J. Meeßen ◽  
T.H. Herzog ◽  
M. Feist ◽  
R. de la Torre ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Thermal Analysis ◽  
Low Temperature ◽  
Water Retention ◽  
The Other ◽  
Dry Conditions ◽  
Buellia Frigida ◽  
Water Retention Properties ◽  
The Impact ◽  
Hydration And Dehydration

AbstractWe quantitatively studied the hydration and dehydration behaviour of the three astrobiological model lichens Xanthoria elegans, Buellia frigida and Circinaria gyrosa by thermoanalysis and gravimetric isotherm measurements under close-to-Martian environmental conditions in terms of low temperature and low pressure. Additionally, the impact of UVC exposure on the isolated symbionts of B. frigida and X. elegans was studied by thermoanalysis and mass spectrometry as well as by gravimetric isotherm measurements. The thermal analysis revealed whewellite as a component of C. gyrosa which was not found in B. frigida and X. elegans. Neither the water retention nor the thermal behaviour of symbionts changed when irradiated with UVC under dry conditions. On the other hand, UVC irradiation of the wet mycobiont of B. frigida had a distinct impact on the hydration/dehydration ability which was not observed for the mycobiont of X. elegans. Possibly the melanin of B. frigida's mycobiont, that is not present in X. elegans, or a specifically damaged acetamido group of the chitin of B. frigida may be the sources of additional UVC-induced sorption sites for water associated with the UVC exposure.

Microstructure of Ceramic Brick Contaminated by Magnesium Sulphate

2014 ◽  
Vol 92 ◽  
pp. 203-208 ◽  
Author(s):  
Teresa Stryszewska ◽  
Stanisław Kańka
Keyword(s):  
Phase Composition ◽  
Mercury Intrusion Porosimetry ◽  
Ceramic Materials ◽  
Ceramic Brick ◽  
Gradual Loss ◽  
Test Materials ◽  
Sulfate Salts ◽  
The Stability ◽  
The Impact

Durability of building ceramics is determined by phase composition, the presence of various admixtures and porosity structure. Insertion of salts into the ceramic materials of bricks causes a gradual loss of the original properties of the material. The studies presented in this paper relate to the impact of magnesium sulfate salts to the microstructure change of the ordinary ceramic brick treated. Two types of ceramic bricks were selected for the studies with significantly different properties of shard, which through capillary action were brought to full saturation by solutions. Determination of changes in microstructure of the test materials by the process of crystallization of salts derived from solutions and the crystallization of the corrosion products, was carried out by observation of the microstructure in SEM. In selected places, chemical analysis was performed to determine the changes in the phase composition of the test materials. As a very important factor that affects the stability of ceramic brick is its porosity, pore structure determination was performed by mercury intrusion porosimetry. Based on the received results, the categorization of pores was presented with the indication of priority place of accumulation of crystallizing salts.

scholarly journals Procesamiento del Té Verde, enriquecido con Vitamina C y Superóxido Dismutasa para la obtención de una bebida funcional antioxidante / Processing of Green Tea, enriched with Vitamin C and Superoxide dismutase for the obtainment of an antioxidant functional Drink

Ciencia Unemi ◽  
2016 ◽  
Vol 9 (20) ◽  
pp. 100
Author(s):  
Carlos Rivera Loja ◽  
Maria Carrillo Rodriguez ◽  
Nibia Novillo Luzuriaga ◽  
Roddy Peñafiel Leon ◽  
Fernando Landines Vera
Keyword(s):  
Superoxide Dismutase ◽  
Vitamin C ◽  
Green Tea ◽  
The United States ◽  
The Stability ◽  
Functional Drink ◽  
The Impact ◽  
Harmful Effects ◽  
Superóxido Dismutasa

Existen estudios que analizan el impacto de los antioxidantes frente a los radicales libres, los cuales neutralizan el exceso de los mismos para proteger las células de sus efectos dañinos y prevenir el desarrollo de enfermedades. En este trabajo se presentan los resultados de la elaboración de una bebida funcional a base de té verde, a la cual se añadió Superóxido Dismutasa y Vitamina C, con el fin de determinar el efecto antioxidante. Se estudiaron los principales componentes antioxidantes del té verde. Una vez elaborado el producto se valoró su estabilidad, natural y acelerada, con resultados dentro de los rangos establecidos. Se usó como instrumento de análisis el HPLC, para la determinación de Superóxido Dismutasa y para la valoración de ácido ascórbico se usó el método volumétrico, ambos establecidos en la Farmacopea de los Estados Unidos (USP). Se concluye que es posible desarrollar la bebida, debido a que la estabilidad de la SOD fue adecuada para el producto desarrollado a lo largo de los tres meses de su estudio. ABSTRACTThere are studies that analyze the impact of antioxidants against free radicals which neutralize their excess, to protect cells from its harmful effects and prevent the development of disease. In this paper, the results of the development of a functional drink based on green tea, which was added with superoxide dismutase and vitamin C in order to determine the antioxidant effect are presented. The main antioxidant components of green tea were studied. Once the product was developed its stability was assessed, both natural and accelerated, giving results according to required specifications; HPLC was the equipment used for determination of Superoxide Dismutase and for the assessment of ascorbic acid, the volumetric methods were used , both established in the United States Pharmacopeia (USP) . It is concluded that it is possible to develop the drink, because the stability of the SOD was suitable for the product developed over three months of study.

Using neutron spectroscopy to measure soil-water retention at high suction ranges

2019 ◽  
Vol 56 (12) ◽  
pp. 1999-2003 ◽  
Author(s):  
Gonzalo G. Carnero-Guzman ◽  
Will P. Gates ◽  
Abdelmalek Bouazza ◽  
Laurie P. Aldridge ◽  
Heloisa N. Bordallo
Keyword(s):  
Water Retention ◽  
Neutron Spectroscopy ◽  
Confined Water ◽  
Geosynthetic Clay Liners ◽  
Soil Water Retention ◽  
Clay Matrix ◽  
Primary Advantage ◽  
Water Retention Properties ◽  
High Suction

Laboratory determination of water retention curves for geosynthetic clay liners (GCLs) and their bentonite components are time-consuming, especially for high suction ranges. This paper explores the potential use of neutron spectroscopy as a useful method to assess the water retention properties of montmorillonite at suction levels >10 MPa for GCL studies. The results from neutron spectroscopy are in good agreement with traditional methods when assessing the water retention of bentonite and GCLs. Additionally, the primary advantage of neutron scattering is that, contrary to conventional methods, water populations within the clay matrix, such as bulk-like water, confined water, and structure OH, are observed and can be quantified independently.

scholarly journals The Impact of Land-Use on the Hierarchical Pore Size Distribution and Water Retention Properties in Loamy Soils

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 339 ◽  
Author(s):  
Pavel Dlapa ◽  
Dávid Hriník ◽  
Andrej Hrabovský ◽  
Ivan Šimkovic ◽  
Hubert Žarnovičan ◽  
...  
Keyword(s):  
Land Use ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Water Retention ◽  
Arable Soil ◽  
Organic Carbon Content ◽  
Hierarchical Pore ◽  
Water Retention Properties ◽  
The Impact

Soil hydraulic properties are very sensitive to land-use in regions susceptible to physical degradation. Intensive agricultural practices often lead to soil compaction and erosion in the investigated area. The main goal of this paper was to evaluate the impact of land-use on the pore size distribution and water retention in loamy soils. The soil water retention curve (SWRC) combined the total porosity and the water retention of the undisturbed sample at 3, 10, 31, 100, 310, and 1000 hPa suctions and the disturbed sample at 1.5 MPa. The triple-exponential model approximated the curve’s course, and its derivative defined the distinct macro-, structural, and textural pore maxima, with characteristic suctions corresponding to SWRC inflection points. The soil organic carbon content had the greatest influence on the content of all three pore classes. The water retention properties followed the hierarchical pore size distribution in the four research plots and decreased in the identical orchard > forest > grassland > arable soil order. These results show that the orchard and forest areas are the most appropriate land uses with respect to porosity and water retention, while the grassland has not fully recovered after its conversion from arable soil and remains relatively poor, and the arable soil properties are the worst.

scholarly journals Effect of microbial UGmax enricher on soil physical and water retention properties

2018 ◽  
Vol 69 (4) ◽  
pp. 243-250
Author(s):  
Mirosław Orzechowski ◽  
Jacek Długosz ◽  
Sławomir Smólczyński ◽  
Barbara Kalisz ◽  
Paweł Sowiński ◽  
...  
Keyword(s):  
Bulk Density ◽  
Water Retention ◽  
Particle Density ◽  
Soil Bulk Density ◽  
Temperate Climate ◽  
Water Capacity ◽  
Available Water ◽  
Available Water Capacity ◽  
Water Retention Properties ◽  
The Impact

Abstract The paper presents the impact of UGmax enricher on soil physical and water retention properties. The experiment was established in 2005 in a 2 ha field 9 km from Lidzbark Warmiński in the village of Budniki. The studied soils were classified as Cambisols and Luvisols (IUSS Working Group WRB 2015), and they were formed from glaciolimnic deposits. Soil bulk density, soil particle density, texture, total porosity and water retention properties using low and high-pressure chambers were determined. The use of UGmax enricher on loamy soils used as arable lands in temperate climate of north-eastern Poland caused significant decrease of soil bulk density, increase of available water capacity and readily available water capacity. Statistically significant differences between examined soil properties were observed in most studied years.

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