scholarly journals Methods Development for the Constrained Elastic Modulus Investigation of Organic Material in Natural Soil Conditions

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6842
Author(s):  
Zygmunt Meyer ◽  
Magdalena Olszewska
Keyword(s):  
Modulus Of Elasticity ◽  
Soil Classification ◽  
Organic Soil ◽  
Soil Conditions ◽  
Natural Soil ◽  
Methods Development ◽  
Constrained Modulus ◽  
Deformation State ◽  
Total Settlement ◽  
Elasticity Measurement

Compressibility is one of the most important mechanical properties of soil. The parameter that characterizes compressibility is the constrained modulus of elasticity. Knowledge of this is important to calculate the settlement of a structure foundation on peat material. According to soil classification by EN ISO 14688-2, peat is an organic soil that contains min. 20% organic matter. It is a highly organic type of soil. Peat material has large compressibility. The value of the constrained elasticity modulus for peat is ca. 400 kPa, while it may be ca 1.0–1.6 MPa for consolidated peat. Due to the extensive range of the modulus, experimental research in this field is proposed. It is suggested to load the peat material layer with an embankment and to determine its total settlement. Based on this, a program was developed to determine the settlement–strain relationship. The authors propose an approach according to two models: the first is based on constant stress distribution in the soil with an oedometer test. The second considers the variability of stresses in the soil and the influence of the loaded area. Both methods were tested based on numerical simulations, and then an experimental field in Szczecin was used. The formulae for the constrained modulus of elasticity measurement were derived; in practical conditions, a uniaxial deformation state can be used with the combination of the total settlement.

scholarly journals Ground-exploring routes of the Volyn region

2017 ◽  
pp. 179-192
Author(s):  
Pavlo Kucher ◽  
Ivan Voloshyn ◽  
Andrii Kukhtiy
Keyword(s):  
Chemical Properties ◽  
Soil Science ◽  
Soil Conditions ◽  
Natural Soil ◽  
Peat Bogs ◽  
Forest Steppe ◽  
Podzolic Soils ◽  
Typical Chernozems ◽  
Soil Forming Processes ◽  
Soil Distribution

The article highlights the features of conducting soil excursion cognitive routes. We have proposed a comprehensive cognitive route for tourists of various degrees of educational level: schoolchildren and students of natural sciences. For each type of tourists, according to their wishes, information on natural features, soil cover and other excursion facilities are provided. Complex excursions are offered to attract more tourists. It is proposed to include in excursion routes: monuments and memorable places, architectural, archaeological, historical, sacral, museum and other valuable tourist objects. The excursion route in the Volyn region consists of eight soil study areas, where information is provided on the natural soil conditions, the most common types of soils, including gray forest soils, typical chernozems, sod-podzolic soils, peat soils and peat bogs. Two soils study areas are located on the forest-steppe area, where information on the main types of soils, their granulometric composition, and chemical properties are highlighted. The third-eighth field is laid within Volyn Polissya. Based on the study of the features of soil distribution, a soil-cognitive tourism route within the limits of the Forest-steppe and Volyn Polissya has been developed. The tour consists of information on the natural features of this territory, which testify to the conditions of the soil-forming processes, depending on the characteristics of natural conditions. During the soil study route, the peculiarities of distribution of the main types of soils and soil-forming rocks are highlighted. A table is prepared, in which a brief description of all types of soils found on the route and interesting tourist objects is located. Key words: soil, soil science cognitive field, tourist object, soil science route.

Evidence that tropical soil environment can support the growth of Escherichia coli

1998 ◽  
Vol 38 (12) ◽  
pp. 171-174 ◽  
Author(s):  
M. N Byappanahalli ◽  
R. S. Fujioka
Keyword(s):  
Escherichia Coli ◽  
Water Quality ◽  
Tropical Soil ◽  
Soil Conditions ◽  
Natural Soil ◽  
Minimal Amount ◽  
Soil Environment ◽  
Faecal Coliforms ◽  
E Coli ◽  
Faecal Bacteria

Concentrations of faecal coliforms and Escherichia coli in environmental waters have historically been used to establish recreational water quality standards. When these bacteria are used as indices of water quality, it is assumed that there are no significant environmental sources of these bacteria which are unrelated to direct faecal contamination. However, we have previously reported that in tropical island environments such as in Hawaii, these faecal indicators are consistently found at high concentrations in all streams and the source of these faecal bacteria is the soil. To become so well established in soil we hypothesized that these faecal bacteria must have the ability to multiply in the natural soil environment at ambient temperature (23–25°C). Three lines of evidence support this hypothesis: (1) E. coli was shown to grow on 10% soil extract agar, (2) populations of faecal coliforms and E. coli from sewage were shown to immediately increase by about three logs when simple nutrients (glucose and salts) were added to natural soil and (3) faecal coliforms and E. coli increased by two logs within 24 h when a minimal amount of sewage was added to cobalt-irradiated soil. These results indicate that tropical soil environments provide sufficient means to support the growth of faecal coliforms and E. coli. However, under natural soil conditions, indigenous soil microorganisms are much more efficient in obtaining nutrients and we hypothesize that faecal bacteria grow sporadically in response to available nutrients.

scholarly journals Impact of Auxins on Vegetative Propagation through Stem Cuttings of Couroupita guianensis Aubl.: A Conservation Approach

Scientifica ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Mahipal S. Shekhawat ◽  
M. Manokari
Keyword(s):  
Acetic Acid ◽  
Vegetative Propagation ◽  
Adventitious Shoots ◽  
Conservation Strategy ◽  
Soil Conditions ◽  
Natural Soil ◽  
Naphthalene Acetic Acid ◽  
Stem Cuttings ◽  
Medicinal Tree ◽  
Couroupita Guianensis

The present study explores the potential of exogenous auxins in the development of adventitious shoots and roots from shoot cuttings of Couroupita guianensis (Nagalingam), a threatened tree. Experiments were conducted to assess the effect of various concentrations of auxins on shoot and root morphological traits of stem cuttings in the greenhouse. Amongst the auxins tested, significant effects on number of shoot buds’ induction and their growth were observed with α-Naphthalene Acetic Acid (NAA) treated nodal cuttings. Cent percentage of the stem cuttings of C. guianensis were rooted and shoots were induced when pretreated with 400 mg L−1 NAA for 5 min. Maximum 79% of stem cuttings responded to pretreatment of 300 mg L−1 indole-3-butyric acid (IBA) for 5 min, and 75% of stem cuttings induced shoots with 400 mg L−1 indole-3-acetic acid (IAA). Presence of at least 5 nodes on stem cuttings was found to be prerequisite for root and shoot induction. About 92% of plants were survived under natural soil conditions raised from the stem cuttings. This is the first report of vegetative propagation of C. guianensis through stem cuttings which could be used for conservation strategy and sustainable utilization of this threatened medicinal tree.

Growth of Odontia bicolor in vitro

1970 ◽  
Vol 48 (3) ◽  
pp. 447-452
Author(s):  
Denis Lachance
Keyword(s):  
Mineral Soil ◽  
Dry Weight ◽  
Organic Soil ◽  
Balsam Fir ◽  
Natural Soil ◽  
Malt Extract ◽  
Optimum Temperature ◽  
Extract Medium ◽  
Mycelial Strands

The growth of Odontia bicolor in soil and in balsam fir wood was studied. In steam-sterilized organic soil, the fungus grows rapidly, producing a scanty and uniform growth, whereas in propylene oxide gas-treated or natural organic soil, it forms mycelial strands. In mineral soil, the fungus reacts as in organic soil except that growth is more sparse. The fungus grows through natural soil and colonizes new substrate more rapidly when mycelial strands are linked to an appropriate food base.The optimum temperature for growth on a 2.5% malt extract medium occurs between 22 and 27 °C. The fungus grows well in balsam fir wood at any moisture content above 42% of the oven-dry weight, and twice as fast in sapwood as in heartwood. Its growth is not influenced by previous storage of the wood, either frozen (−20 °C) or at a temperature of 2 °C for up to 16 weeks.

scholarly journals A qualitative study of the nodulating ability of legumes of Pakistan

2014 ◽  
Vol 66 (3-4) ◽  
pp. 387-391
Author(s):  
Mohammad Athar
Keyword(s):  
Garden Soil ◽  
Great Promise ◽  
Soil Conditions ◽  
Natural Soil ◽  
Agricultural Ecosystem ◽  
Rhizobial Inoculation ◽  
Wide Range ◽  
Wild Legumes ◽  
Mineralizable Nitrogen ◽  
First Time

<em>Legume-Rhizobium</em> symbiosis accumulates substantial amounts of mineralizable nitrogen which help in ecological rehabilitation of degraded soils and increase the soil fertility in agricultural ecosystem. Nodulation was studied in 72 legume species from various parts of Pakistan. All the species of <em>Papilionoideae</em> and <em>Mimosoideae</em> were nodulated whereas all the species examined in <em>Caesalpinioideae</em> were non-nodulated. Attempts to elicit nodulation in <em>Caesalpinioid</em> species by rhizobial inoculation were not successful and they were accepted as lacking nodulating ability. Nodulation is reported for the first time in 6 species within 3 genera of <em>Mimosoideae</em> and 9 species within 5 genera of <em>Papilionoideae</em>. Majority of the species were abundantly nodulated under natural soil conditions or when grown in uninoculated garden soil indicating distribution of wide range of naturalized rhizobia. The study shows that the wild legumes hold great promise for inclusion in revegetation of denuded and derelict ecosystems.

scholarly journals N2O Fluxes and Related Processes of Denitrification in Acidified Soil

2020 ◽  
Author(s):  
Qian Zheng ◽  
Junjun Ding ◽  
Qiaozhen Li ◽  
Chunying Xu ◽  
Wei Lin ◽  
...  
Keyword(s):  
Soil Ph ◽  
Irrigation Water ◽  
Soil Acidification ◽  
N Fertilizer ◽  
Soil Conditions ◽  
Natural Soil ◽  
Large Contribution ◽  
Total N ◽  
Mapping Approach ◽  
The Impact

Abstract In North China, high levels of N fertilizer and irrigation water are used in fields, which cause considerable N2O fluxes via several pathways, especially anaerobic denitrification. Anaerobic denitrification is regarded as an important microbial process for N2O production in soils with a low O2 level and high N and labile C availability (the typical soil conditions caused by high levels of N fertilizer and irrigation water in the field). We conducted an anaerobic incubation experiment to determine the impact of soil acidification (with a series of soil pH levels, pH 6.2, pH 7.1, and pH 8.7) on N2O source partitioning with the addition of KNO3 and glucose. Natural abundance isotope techniques and gas inhibitor technique were applied to analyze the N2O flux derived from fungal denitrification and bacterial denitrification and its isotopocule characteristics emitted from soils after the addition of NO- 3 and glucose. A mapping approach was used to obtain further insight into the N2O production processes. Our findings confirmed that soil pH strongly controlled the N2O production and reduction rates of denitrification. Soil acidification significantly increased N2O emissions varied from 0.76 mg N kg-1 for natural soil (pH 8.7), to 1.88 mg N kg-1 for pH 7.1, and to 2.35 mg N kg-1 for pH 6.2, and had a blockage effect on the reduction of N2O to N2. The addition of carbon sources promoted complete denitrification. We assumed a higher contribution of fungal denitrification to N2O production compared to total N2O emission associated with acidified soil. A promotion of the contribution of fungal denitrification-derived N2O was indeed observed with decreasing pH, increasing from 0.28 mg N kg-1 for pH 8.7 to 0.94 mg N kg-1 for pH 6.2. The addition of glucose further increased the contribution of fungal denitrification to N2O production from 0.99 mg N kg-1 for pH 8.7 to 3.66 mg N kg-1 for pH 6.2. The mapping approach provided rational results for correcting N2O reduction compared with the acetylene inhibition method. The results calculated by both methods indicated a reasonably large contribution of fungal denitrification to total N2O production in acidified soils.

scholarly journals How does silica affect Fe(II)-catalysed transformation of ferrihydrite and lepidocrocite?

2020 ◽  
Author(s):  
Katrin Schulz ◽  
Laurel Kathleen ThomasArrigo ◽  
Katherine Ann Rothwell ◽  
Ruben Kretzschmar
Keyword(s):  
Iron Atom ◽  
Solid Phase ◽  
Transformation Process ◽  
Soil Conditions ◽  
Natural Soil ◽  
X Ray Diffraction ◽  
Mineral Transformation ◽  
Iron Mineral ◽  
Mineral Phases ◽  
Reducing Conditions

&lt;p&gt;Ferric iron (Fe(III)) minerals, such as ferrihydrite and lepidocrocite, can be reduced to ferrous iron (Fe(II)) through microbial reductive dissolution under reducing soil conditions, to form dissolved Fe(II) or mixed Fe(II)-Fe(III) mineral phases. The dissolved Fe(II) catalyses iron mineral transformation to more crystalline iron phases. Silica (Si), in the form of silicic acid, is an ubiquitous component of natural soil solutions and is known to hinder the iron mineral transformation process. However, the mechanisms and the mineral phases that are formed during ferrihydrite and lepidocrocite transformation in the presence of Si remain unclear. We reacted ferrihydrite, Si-ferrihydrite co-precipitates, lepidocrocite and Si-adsorbed lepidocrocite with 0.3&amp;#160;mM and 3&amp;#160;mM isotopically labelled &lt;sup&gt;57&lt;/sup&gt;Fe(II) for four weeks. At six time points, we sampled the solid and the aqueous phase, to follow iron mineral transformation by X-ray diffraction and dissolved Fe(II) dynamics. In addition, we tracked the iron atom exchange between the aqueous and the solid phase by measuring the &lt;sup&gt;57/56&lt;/sup&gt;Fe isotope ratio in filtrates and dissolved solid phases. Our data demonstrates the hindering effect of Si on Fe(II) catalysed ferrihydrite and lepidocrocite transformation. The presence of Si decreased the initial Fe(II) adsorption and strongly slowed down the iron atom exchange, especially in the lepidocrocite treatment. Collectively, the results of this study demonstrate, how Si can impact iron mineral transformation in soils with different Fe(II) release potentials under reducing conditions.&lt;/p&gt;

Amalgamation and Harmonization of Soil Survey Reports into a Multi-purpose Database

2020 ◽  
Author(s):  
Shane Robert Furze ◽  
Paul Arp
Keyword(s):  
New Brunswick ◽  
Soil Properties ◽  
Vegetation Type ◽  
Soil Classification ◽  
Parent Material ◽  
Soil Survey ◽  
Soil Horizon ◽  
Soil Conditions ◽  
Soil Parent Material ◽  
Soil Surveys

There is a growing demand for standardized, easily accessible and detailed information pertaining to soil and its variability across the landscape. Typically, this information is only available for select areas in the form of local or regional soil surveys reports which are difficult, and costly, to develop. Additionally, soil surveying protocols have changed with time, resulting in inconsistencies between surveys conducted over different periods. This article describes systematic procedures applied to generate an aspatial, terminologically- and unit-consistent, database for forest soils from county-based soil survey reports for the province of New Brunswick, Canada. The procedures involved (i) amalgamating data from individual soil surveys following a hierarchical framework, (ii) summarizing and grouping soil information by soil associations, (iii) assigning correct soil associates to each association, with each soil associate distinguished by drainage classification, (iv) assigning pedologically-correct horizon sequences, as identified in the original soil surveys, to each soil associate, (v) assigning horizon descriptors and measured soil properties to each horizon, as outlined by the Canadian System of Soil Classification, and (vi) harmonizing units of measurement for individual soil properties. Identification and summarization of all soil associations (and corresponding soil associates) was completed with reference to the principal soil-forming factors, namely soil parent material, topographic surface expressions, soil drainage, and dominant vegetation type(s). This procedure, utilizing 17 soil surveys, resulted in an amalgamated database containing 106 soil associations, 243 soil associates, and 522 soil horizon sequences summarizing the variability of forest soil conditions across New Brunswick.

THE SOIL-BLOCK WASHING METHOD IN QUANTITATIVE ROOT STUDY

1937 ◽  
Vol 15c (2) ◽  
pp. 33-57 ◽  
Author(s):  
T. K. Pavlychenko
Keyword(s):  
Plant Development ◽  
Root Systems ◽  
New Technique ◽  
Soil Conditions ◽  
Natural Soil ◽  
Soil Block ◽  
Washing Method ◽  
A New Technique ◽  
Considerable Detail

It has been observed consistently that competition among plants first takes place between the root systems, and that the nature, vigor, extent and distribution of the root systems have an important bearing, on the development of top growth. A new technique for root studies, the Soil-block Washing Method, is described in considerable detail. This method enables the investigator to procure entire root systems at any stage of plant development, from plants grown under natural soil conditions.

scholarly journals MULTIPLE CRITERIA SELECTION OF PILE-COLUMN CONSTRUCTION TECHNOLOGY

2012 ◽  
Vol 18 (6) ◽  
pp. 834-842 ◽  
Author(s):  
Edmundas Kazimieras Zavadskas ◽  
Saulius Sušinskas ◽  
Alfonsas Daniūnas ◽  
Zenonas Turskis ◽  
Henrikas Sivilevičius
Keyword(s):  
Decision Making ◽  
Multiple Criteria Decision Making ◽  
Multiple Criteria ◽  
Soil Conditions ◽  
Natural Soil ◽  
Construction Technology ◽  
In Situ Investigation ◽  
Pile Column ◽  
Decision Making Model ◽  
Selection Of

Numerous alternatives exist for foundation systems and construction technologies. The systems can be described by different criteria values which are incorporated in the conventional design process. Decision on the most suitable construction technology is vital for success and depends on many effectiveness criteria. The business success depends on the right choice. The mandate of a construction management researcher is to use rational, systematic, science-based techniques to inform and improve various decisions. The paper presents multiple criteria decision making model for selection of a pile-column technology. The technological criteria are determined by an experimental study. Based on in-situ investigation of natural soil conditions, criteria values are determined. The decision making model incorporates five different methods and techniques. To solve a problem, it uses three multiple criteria decision making methods. Integrated criteria weights are determined by using the analytic hierarchy process and the expert judgement method. This model could be used to solve complicated problems pertaining to the selection of a construction technology.

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