scholarly journals Numerical Modelling of the Subsoil Zone between Stone Columns

2019 ◽  
Vol 27 (4) ◽  
pp. 32-39
Author(s):  
Jakub Stacho ◽  
Monika Sulovska
Keyword(s):  
Radial Displacement ◽  
Numerical Models ◽  
Stone Columns ◽  
Deformation Properties ◽  
Practical Design ◽  
Replacement Technique ◽  
Strength And Deformation ◽  
The Difference ◽  
Final Settlement

Abstract Designing the improvement of soil using stone columns is usually based on simplified analytical or numerical models. Stone columns installed using a vibro-replacement technique can cause radial displacement of the original soil. It can cause radial compaction of the soil and increase the values of the strength and deformation properties, which are usually ignored in a practical design. The paper presents the results of a numerical analysis of a road embankment based on subsoil improved using stone columns. The changes in the properties of the original subsoil compacted by stone columns were analysed and taken into consideration in the models. The results showed that a model with homogenization of the subsoil and a model with stone columns transferred to continuous walls show similar results of the final settlement as well as the consolidation times. The differences between the values computed and measured were about 28 - 36 %. Taking into account the compacting effect of the original subsoil, the model with stone columns transferred to continuous walls allowed for the determination of more precise results when the difference between the values computed and measured was about 10 %.

scholarly journals Numerical Analysis of Soil Improvement for a Foundation of a Factory Using Stone Columns Made of Different Types of Coarse-grained Materials

2019 ◽  
Author(s):  
Jakub Stacho ◽  
Monika Sulovska
Keyword(s):  
Numerical Analysis ◽  
Accurate Determination ◽  
Soil Improvement ◽  
Coarse Grained ◽  
Stone Columns ◽  
Modified Method ◽  
Geological Conditions ◽  
Deformation Properties ◽  
Final Settlement ◽  
The Impact

Stone columns made of coarse-grained materials and crushed stone are one of the most-used technologies for soil improvement all over the world. Stone columns improve the strength and deformation properties of subsoil and reduce the time required for the consolidation of fine-grained soils. The impact of the improvement depends on the properties of the original subsoil as well as the properties of the coarse-grained materials used for the stone columns. The article deals with the effects of the properties of coarse-grained materials for stone columns on the settlement and consolidation times of improved subsoil for the foundation of a factory. Numerical modeling as a 2D task was performed using Plaxis geotechnical software. The numerical analysis included two methods of modeling stone columns in a plane strain model, i.e., one method often used by practical engineers in the region of Slovakia, and one modified method, which allowed for a more accurate determination of the final settlement and consolidation time. The method modeled stone columns as continuous walls, and the compaction of the soil between the stone columns was taken into account. The results showed that the type of coarse-grained material can significantly affect the final settlement and time of consolidation. Stone columns made of quarry stone were suitable in the given geological conditions regardless of the design of the mesh, while stone columns made of pebble gravel were suitable only with a mesh of 1.5 x 1.5 m.

Predicted and measured stresses and displacements around the Darlington Intake Tunnel

1984 ◽  
Vol 21 (1) ◽  
pp. 147-165 ◽  
Author(s):  
K. Y. Lo ◽  
B. Lukajic
Keyword(s):  
Field Measurements ◽  
Time Dependent ◽  
Long Term Conditions ◽  
Field Instrumentation ◽  
Deformation Properties ◽  
Strength And Deformation ◽  
Short And Long Term ◽  
Keywords Stress

The C.W. Intake Tunnel of the Darlington Nuclear Station is D-shaped in section with a span of 8 m and a length of 925 m beneath Lake Ontario. The tunnel is located in a horizontally bedded limestone with variable shaly interbeds.The geotechnical investigation including in-situ rock stress measurements, and laboratory determination of strength and deformation properties as well as time-dependent behaviour are reported. Design of the tunnel, in particular provisions for "rock squeeze," is described in detail.To verify the design approach adopted and the provisions made, field instrumentation was performed during excavation of the tunnel. The results of field measurements of stresses and displacements were compared with premonitoring analysis. Postmonitoring analyses were also performed using the as-constructed condition. It is shown that the performance of the tunnel is in general agreement with the predicted behaviour in both short and long term conditions. Keywords: stress, displacement, time-dependent deformation, stressmeter, tunnel, rock mechanics, rock squeeze.

scholarly journals EFFECT OF DOSAGE OF REDISPUTABLE POWDERS AND THE TYPE OF LOW-MODULAR INCLUSIONS ON THE PROPERTIES OF FINE-AGGREGATE CONCRETE

2019 ◽  
Vol 46 (2) ◽  
pp. 167-175 ◽  
Author(s):  
A. V. Dolgova ◽  
G. V. Nesvetaev
Keyword(s):  
Fine Aggregate ◽  
Fine Grained ◽  
Deformation Properties ◽  
Low Modulus ◽  
Strength And Deformation ◽  
Properties Of Materials ◽  
Materials Used ◽  
Entrained Air ◽  
Polymer Powders

Objectives Reliability and durability of structures using materials with various properties (plaster coatings, cement glue, new concrete during repair and restoration of structures, etc.) largely depends on the adhesion of the layers and the deformation properties of the coatings. To obtain the required properties of materials used for coatings, modifiers based on polymers and low-modulus inclusions are introduced into the composition of new concretes, for example, entrained air. The aim of the work is to identify some patterns of change in the properties of concrete with the joint introduction of these modifiers.Method Experimental determination of the tensile strength in bending, compression, E-modulus, adhesion to the concrete base by standard methods.Result The influence of separate and joint introduction of dispersible polymer powders and various low-modulus inclusions into the composition of fine-grained concrete has been established.Conclusion The joint introduction to the composition of fine-grained concrete of various low-modulus inclusions and redispersible polymer powders provides a reduction in the stress level during forced deformations due to the different effects additives on the strength and deformation properties and contributes to increased adhesion to the concrete. 

FRACTIONAL DETERMINATIONS OF URINARY 17-KETOSTEROIDS IN HYPEREMESIS GRAVIDARUM

1962 ◽  
Vol 41 (1) ◽  
pp. 123-128 ◽  
Author(s):  
Pentti A. Järvinen ◽  
Sykkö Pesonen ◽  
Pirkko Väänänen
Keyword(s):  
Hyperemesis Gravidarum ◽  
First Trimester ◽  
Control Group ◽  
Before And After ◽  
Daily Urine ◽  
First Trimester Of Pregnancy ◽  
The Difference

ABSTRACT The fractional determination of 17-ketosteroids in the daily urine was performed in nine cases of hyperemesis gravidarum and in four control cases, in the first trimester of pregnancy both before and after corticotrophin administration. The excretion of total 17-KS is similar in the two groups. Only in the hyperemesis group does the excretion of total 17-KS increase significantly after corticotrophin administration. The fractional determination reveals no difference between the two groups of patients with regard to the values of the fractions U (unidentified 17-KS), A (androsterone) and Rest (11-oxygenated 17-KS). The excretion of dehydroepiandrosterone is significantly higher in the hyperemesis group than in the control group. The excretion of androstanolone seems to be lower in the hyperemesis group than in the control group, but the difference is not statistically significant. The differences in the correlation between dehydroepiandrosterone and androstanolone in the two groups is significant. The high excretion of dehydroepiandrosterone and low excretion of androstanolone in cases of hyperemesis gravidarum is a sign of adrenal dysfunction.

THE SUBJECT FIELD OF INSTITUTIONAL EDUCATION: THE SENSE AND PROSPECTS OF DEVELOPMENT IN UKRAINE

2020 ◽  
pp. 25-38
Author(s):  
Irina Mordous
Keyword(s):  
Decisive Role ◽  
Subject Field ◽  
National Education ◽  
Progressive Development ◽  
Separate Area ◽  
Economic Transformations ◽  
The Difference ◽  
The Individual ◽  
Political Economic

The development of modern civilization attests to its decisive role in the progressive development of institutions. They identified the difference between Western civilization and the rest of the world. Confirmation of the institutional advantages of the West was its early industrialization. The genesis and formation of institutionalism in its ideological and conceptualmethodological orientation occurs as a process alternative to neoclassic in the context of world heterodoxia, which quickly spread in social science. Highlighting institutional education as a separate area of sociocultural activity is determined by the factor of differentiation of institutional theory as a whole. A feature of institutional education is its orientation toward the individual and his/her transformation into a personality. The content of institutional education is revealed through the analysis of the institution, which includes a set of established customs, traditions, ways of thinking, behavioral stereotypes of individuals and social groups. The dynamics of socio-political, economic transformations in Ukraine requires a review of the foundations of national education and determination of the prospects for its development in the 21st century in the context of institutionalism.

scholarly journals Possibility of Human Gender Recognition Using Raman Spectra of Teeth

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3983
Author(s):  
Ozren Gamulin ◽  
Marko Škrabić ◽  
Kristina Serec ◽  
Matej Par ◽  
Marija Baković ◽  
...  
Keyword(s):  
Raman Spectra ◽  
Principal Component ◽  
Support Vector ◽  
Gender Recognition ◽  
Proof Of Concept ◽  
Male And Female ◽  
Tooth Type ◽  
Tooth Apex ◽  
The Difference

Gender determination of the human remains can be very challenging, especially in the case of incomplete ones. Herein, we report a proof-of-concept experiment where the possibility of gender recognition using Raman spectroscopy of teeth is investigated. Raman spectra were recorded from male and female molars and premolars on two distinct sites, tooth apex and anatomical neck. Recorded spectra were sorted into suitable datasets and initially analyzed with principal component analysis, which showed a distinction between spectra of male and female teeth. Then, reduced datasets with scores of the first 20 principal components were formed and two classification algorithms, support vector machine and artificial neural networks, were applied to form classification models for gender recognition. The obtained results showed that gender recognition with Raman spectra of teeth is possible but strongly depends both on the tooth type and spectrum recording site. The difference in classification accuracy between different tooth types and recording sites are discussed in terms of the molecular structure difference caused by the influence of masticatory loading or gender-dependent life events.

scholarly journals Influence of Erythrocytes on Direct Potentiometric Determination of Sodium and Potassium

1983 ◽  
Vol 20 (2) ◽  
pp. 116-120 ◽  
Author(s):  
P Bijster ◽  
H L Vader ◽  
C L J Vink
Keyword(s):  
Whole Blood ◽  
Potassium Concentration ◽  
Reference Electrode ◽  
Sodium Concentration ◽  
General Phenomenon ◽  
Liquid Junction ◽  
Direct Potentiometry ◽  
The Difference ◽  
Sodium And Potassium

We have shown that the sodium concentration in whole blood measured by direct potentiometry is higher than in plasma. The ‘erythrocyte-effect’, already described by Siggaard Andersen, is most pronounced for instruments equipped with a reference electrode with an open static liquid junction and is thus a general phenomenon. Instruments with a modified liquid junction show less interference. The same phenomenon appears for the determination of the potassium concentration, although the difference between whole blood and plasma, when measured with instruments equipped with a modified liquid junction, can be neglected in practice.

Method for the simultaneous quantification of n-hexane metabolites: application to n-hexane metabolism determination

1996 ◽  
Vol 15 (6) ◽  
pp. 497-503 ◽  
Author(s):  
T. Soriano ◽  
M. Menéndez ◽  
P. Sanz ◽  
M. Repetto
Keyword(s):  
Similar Pattern ◽  
Analytical Procedure ◽  
Daily Basis ◽  
Practical Application ◽  
Simultaneous Quantification ◽  
Exposed Workers ◽  
Before And After ◽  
Time Requirements ◽  
The Difference

1 The described analytical procedure permits the simultaneous determination of the main n-hexane meta bolites in urine. 2-Hexanone, 2-hexanol, 2, 5-hexanediol and 2, 5-hexanedione, were chosen to dose the rats used in this study. All urine samples were collected and analysed on a daily basis, before and after acidic hydrolysis (pH 0.1) by GC/MS. 2-Hexanone, 2, 5-dimethylfurane, γ-valerolac tone and 2, 5-hexanedione were determined before hydro lysis ; 2-hexanol and 2, 5-hexanediol, after hydrolysis; and 5-hydroxy-2-hexanone and 4, 5-dihydroxy-2-hexanone were calculated by the difference between γ-valerolactone and 2, 5-hexanedione with and without hydrolysis, respectively. 2 A metabolic scheme was proposed reflecting the biotransformations undergone by the four compounds assayed. We consider 2, 5-dimethylfurane as a 'true metabolite' because the quantities detected were always greater before hydrolysis. 3 It has been reported that human and rat n-hexane metabolism follow a similar pattern. Therefore, as a practical application and without increasing either sample or time requirements, the simultaneous quantifi cation of the different metabolites and their excretion profile could provide better information about the metabolic situation of exposed workers than the determi nation of 2, 5-hexanedione alone. According to our experimental results, 4, 5-dihydroxy-2-hexanone itself would be a good toxicity indicator.

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