The role of concentrations variability of organic matter in kerogenic shale defluidisation on the catagenic depths

The Baltic kerogenic shale – kukersites (О2kk) were considered high-carbon marls which consist of three rock-forming components: organic matter (kerogen), carbonates and terrigenous material. As example used are data of the other high-carbon rocks. It is shown that increased concentrations of organic matter predetermine a number of features of these rocks (reduced density, reduced strength, etc.). The concentrations variability of the organic matter makes conditions the heterogeneity of the intraformational space, the anisotropy of many parameters, as well as the manifestation unevenness of the fluid-generation and evacuation capabilities. It was found that in kukersite shales fluid-generating properties can appear at the earliest stages of catagenesis. The role of areas with the maximum qualities of organic matter in the defluidisation of the shale coals is emphasized: here the more intensive generation of gas-liquid products and increased strength contribute to the earlier formation of drainage microcracks and fluid fractures. The appearance of shrinkage cracks due to catagenic losses of organic matter and usually uneven volume contraction and due to fluidgenerating shale coals is substantiated. The possibility of fluid-generating shale coals losing it lithological individuality during of it defluidisation is found out. Keywords: organic matter; oil shale; kukersite; defluidization; catagenesis; hydrocarbons.

Energy power parameter effect of hot rolling on the formation of the structure and properties of low-alloy steels

The temperature and degree of hot deformation for steel 10HFTBch have been determined. This made it possible to ensure an increase in the mechanical properties of this steel, namely, the ultimate strength up to 540–560 MPa, as well as the relative elongation up to 25–29 %. As a result, it became possible to increase the service life of wheels with increased carrying capacity. This, in turn, will make it possible to increase the load of the transported cargo by motor vehicles several times. The mechanism of the influence of the energy-power parameters of rolling on the formation of the macro- and microstructure of a two-phase steel in the process of hot deformation is disclosed. The applied scheme provided an increase in the homogeneity of the structure of the developed steel, which saved the central part of the rolled section from overheating. It has been established that a decrease in the temperature of the end of deformation leads to a decrease in the size of the recrystallized austenite grain, and, consequently, to a refinement of the ferrite grain. Also an important factor in preventing the growth of ferrite grains in the upper part of the ferritic region is the abolition of cooling of the steel in coils. The recommended mode for multicomponent alloy steel 10HFTBch is as follows: the temperature of the end of rolling is 850 °C, the beginning of accelerated cooling is 750 °C, and the temperature of strip coiling into a coil is 600 °C. The basis for ensuring the increased strength of two-phase steels is the ratio and distribution of structural fractions – ferrite (initial and precipitated from austenite), as well as martensite. When hardened by such traditional "martensite formations" as manganese, the ability to control properties is limited. This is reflected in a narrow range of variation in the strength and ductility of the developed steel. The optimal combination of strength characteristics of plastic properties reduces the metal consumption of the product by 15–25 %.

COMPARATIVE ANALYSIS OF NATM CONSTRUCTION TECHNOLOGIES OF DNIPRO METRO ESCALATOR TUNNEL

Purpose. On the basis of the comparative analysis to carry out a substantiation of the most expedient and rational way of strengthening of a weak massif during a construction of Dnipro metro escalator tunnels by NATM. Methodology. To achieve this goal, an analysis of construction technologies in weak soils was conducted. The most used technologies are Forepoling Umbrella System (FUS), artificial ground freezing and chemical cementation. The peculiarities of carrying out each of the technologies for the conditions of inclined production were analyzed. It is determined how each of the technologies is applied to escalator tunnels and implements the strengthening of weak soil. Findings. The advantages and disadvantages of three technologies for fixing weak soil around the escalator tunnel are identified. Based on comparative analysis, it was found that the only technology that provides increased strength parameters of loamy soils, characteristic for the upper part of the escalator tunnel of the Dnipro metro, is the technology of chemical strengthening (cementation). In some cases, if necessary, short sections of sloping course, characterized by particularly weak soil, can be supported by several pipes, without creating a continuous leading mount. The results of the analysis are the basis for further substantiation of cementation, which creates a multilayer system "reinforced soil massif – temporary fastening – permanent lining". Originality. Based on the results of comparative analysis of three technologies for escalator tunnel construction by NATM, it is proved that the use of cementation not only increases the strength of the soil during drilling, but also further in operation serves as an additional element of the multilayer system "reinforced soil massif – temporary fastening – permanent lining". Practical value. In the course of research, the substantiation of cementation as the most rational and effective technology of strengthening of the surrounding weak massif at construction of the Dnipro metro was carried out.

Maternal perception of fetal movements: A qualitative description

<p>Background: Maternal perception of decreased fetal movements is a specific indicator of fetal compromise, notably in the context of poor fetal growth. There is currently no agreed numerical definition of decreased fetal movements, with subjective perception of a decrease on the part of the mother being the most significant definition clinically. Both qualitative and quantitative aspects of fetal activity may be important in identifying the compromised fetus.Yet, how pregnant women perceive and describe fetal activity is under-investigated by qualitative means. The aim of this study was to explore normal fetal activity, through first-hand descriptive accounts by pregnant women. Methods: Using qualitative descriptive methodology, interviews were conducted with 19 low-risk women experiencing their first pregnancy, at two timepoints in their third trimester. Interview transcripts were later analysed using qualitative content analysis and patterns of fetal activity identified were then considered along-side the characteristics of the women and their birth outcomes. Results: Fetal activity as described by pregnant women demonstrated a sustained increase in strength, frequency and variation from quickening until 28-32 weeks. Strength of movements continued to increase at term, but variation in movement types reduced. Kicking and jolting movements decreased at term with pushing or stretching movements dominating. In this study increased strength and frequency of movements at term as determined qualitatively by the mother was associated with higher mean customised birthweight of newborns, whilst decreased frequency was in all cases associated with either maternal obesity, customised birthweight under the 20th centile or operative delivery for non-reassuring fetal status. A novel finding of a complex pattern of fetal movements in relation to mealtimes is reported here. More than a third of participants (37%) described marked increases in fetal movements in response to hunger, in many cases subsiding postprandially. The women who described this pattern in response to hunger and eating, subsequently gave birth to infants significantly smaller (mean difference 364gm) than those who did not describe a fetal response to hunger. Patterns of fetal movements were reported to be influenced by time of day, maternal position and activity, with an inverse relationship between maternal activity and fetal activity described by all participants. Conclusions: Maternal descriptions of fetal movements with advancing gestation and in relation to time of day are consistent with fetal activity as described in ultrasound studies, lending reliability to the maternal account. Maternal perception of fetal movements in response to environmental stimuli such as maternal meals and maternal position-changes may constitute a maternal-fetal communication in the interests of maintaining the pregnancy. Pregnant women are reassured by fetal movements occurring at a usual time or situation, suggesting that maternal monitoring of fetal movements is a dynamic process taking into account a broad range of fetal functions.</p>

Maternal perception of fetal movements: A qualitative description

<p>Background: Maternal perception of decreased fetal movements is a specific indicator of fetal compromise, notably in the context of poor fetal growth. There is currently no agreed numerical definition of decreased fetal movements, with subjective perception of a decrease on the part of the mother being the most significant definition clinically. Both qualitative and quantitative aspects of fetal activity may be important in identifying the compromised fetus.Yet, how pregnant women perceive and describe fetal activity is under-investigated by qualitative means. The aim of this study was to explore normal fetal activity, through first-hand descriptive accounts by pregnant women. Methods: Using qualitative descriptive methodology, interviews were conducted with 19 low-risk women experiencing their first pregnancy, at two timepoints in their third trimester. Interview transcripts were later analysed using qualitative content analysis and patterns of fetal activity identified were then considered along-side the characteristics of the women and their birth outcomes. Results: Fetal activity as described by pregnant women demonstrated a sustained increase in strength, frequency and variation from quickening until 28-32 weeks. Strength of movements continued to increase at term, but variation in movement types reduced. Kicking and jolting movements decreased at term with pushing or stretching movements dominating. In this study increased strength and frequency of movements at term as determined qualitatively by the mother was associated with higher mean customised birthweight of newborns, whilst decreased frequency was in all cases associated with either maternal obesity, customised birthweight under the 20th centile or operative delivery for non-reassuring fetal status. A novel finding of a complex pattern of fetal movements in relation to mealtimes is reported here. More than a third of participants (37%) described marked increases in fetal movements in response to hunger, in many cases subsiding postprandially. The women who described this pattern in response to hunger and eating, subsequently gave birth to infants significantly smaller (mean difference 364gm) than those who did not describe a fetal response to hunger. Patterns of fetal movements were reported to be influenced by time of day, maternal position and activity, with an inverse relationship between maternal activity and fetal activity described by all participants. Conclusions: Maternal descriptions of fetal movements with advancing gestation and in relation to time of day are consistent with fetal activity as described in ultrasound studies, lending reliability to the maternal account. Maternal perception of fetal movements in response to environmental stimuli such as maternal meals and maternal position-changes may constitute a maternal-fetal communication in the interests of maintaining the pregnancy. Pregnant women are reassured by fetal movements occurring at a usual time or situation, suggesting that maternal monitoring of fetal movements is a dynamic process taking into account a broad range of fetal functions.</p>

A Study to Establish Correlation Between Rebound Value and Compressive Strength of Concrete Using Materials Available Locally in Nagpur

This study has been taken to investigate the exact rebound-strength relationship of different grades of concrete, as the curves generated for traditional hammers are outdated. Using the material available in the Nagpur region, cube specimens were cast and tested as per IS:516-1959 [1]. Several sets were cast with varying cement contents, decided by mix design, to give a strength range of 10 to 50 Mpa. However, for this study, the Target Mean Strength Standard Deviation factor is not considered. We tested these sets for compressive strengths; each specimen was checked for rebound value for compressive Strength, each specimen was checked for rebound value on four faces. Thus, for each specimen, data for rebound value and Compressive Strength is available. Using this data, a curve for Compressive Strength and rebound value was plotted. The curve generated indicated that the strengths obtained for the same rebound value are higher than that using the traditional curve. There is an increase of about 47% up to a strength of 21 Mpa. From 21 to 38 Mpa, this increase is almost constant to about 30%. From this point forward, the rate of increased Strength reduces by 25% and 14% at 40 Mpa and 45 Mpa, respectively.

Gold Nanoparticles: A Novel Dye for Synthetic Fabrics

<p>Fabric has always been prominent throughout history. In the last 70 years new synthetic fabrics have been developed which mimic the natural fibres but have increased strength, durability and stretchability. Common fibres include Polyester, Nylon and Lycra(R). These fibres can be blended to incorporate the properties of both the individual fibre types. Gold nanoparticles have been found to give the stable deep red colour found in stained glass but the science was not understood until the quantum mechanical work of Mie in 1908 on the interaction of electromagnetic radiation (visible light) with fine particles of matter. It is proposed that gold nanoparticles can be used as stable colourants bound to synthetic fibres and other textiles due to its chemical unreactivity. The most common formation method is the use of a reductant such as poly(ethylene imine), sodium citrate or tannic acid. This thesis reports the research and development of new, novel hybrid materials created by combining the interesting properties of both the synthetic fabrics and gold nanoparticles. Twenty five different methods (broken down into four general categories - pre-made colloids, in-situ reduction, use of external reductant after uptake of gold solution and growth of seed particles) were attempted resulting in fabrics that were a variety of shades and colours including pink, purple, tan and gold. The synthetic fabric-gold nanoparticle hybrid samples were analysed by scanning electron microscopy, energy dispersive spectroscopy, infrared spectroscopy, ultraviolet/visible reflectance spectroscopy, x-ray photoelectron spectroscopy, fluorescence spectroscopy and ColourQuest measurements. A sample was also subjected to industry standard "abrasion" and colourfastness tests in which it gained the highest mark possible, showing no staining of other fabrics under dry rub conditions. Atomic absorption measurements were performed on solutions after the fabric was removed in order to confirm the amount of gold uptake by the fabric samples. Analysis showed that a range of nanoparticle sizes and shapes were produced which influenced the visual colour of the fabric. The purple samples produced are caused by small particles (<100nm) that have aggregated together. Samples that appear tan or gold in colour have mainly large particles (>500nm) that are either made up of small spheres fused together or are large plates (trigonal, hexagonal); therefore, Mie's laws do not appear to apply. Light coloured samples generally have a few small particles (<100nm) that are spaced out over the fibre surface.</p>

Gold Nanoparticles: A Novel Dye for Synthetic Fabrics

<p>Fabric has always been prominent throughout history. In the last 70 years new synthetic fabrics have been developed which mimic the natural fibres but have increased strength, durability and stretchability. Common fibres include Polyester, Nylon and Lycra(R). These fibres can be blended to incorporate the properties of both the individual fibre types. Gold nanoparticles have been found to give the stable deep red colour found in stained glass but the science was not understood until the quantum mechanical work of Mie in 1908 on the interaction of electromagnetic radiation (visible light) with fine particles of matter. It is proposed that gold nanoparticles can be used as stable colourants bound to synthetic fibres and other textiles due to its chemical unreactivity. The most common formation method is the use of a reductant such as poly(ethylene imine), sodium citrate or tannic acid. This thesis reports the research and development of new, novel hybrid materials created by combining the interesting properties of both the synthetic fabrics and gold nanoparticles. Twenty five different methods (broken down into four general categories - pre-made colloids, in-situ reduction, use of external reductant after uptake of gold solution and growth of seed particles) were attempted resulting in fabrics that were a variety of shades and colours including pink, purple, tan and gold. The synthetic fabric-gold nanoparticle hybrid samples were analysed by scanning electron microscopy, energy dispersive spectroscopy, infrared spectroscopy, ultraviolet/visible reflectance spectroscopy, x-ray photoelectron spectroscopy, fluorescence spectroscopy and ColourQuest measurements. A sample was also subjected to industry standard "abrasion" and colourfastness tests in which it gained the highest mark possible, showing no staining of other fabrics under dry rub conditions. Atomic absorption measurements were performed on solutions after the fabric was removed in order to confirm the amount of gold uptake by the fabric samples. Analysis showed that a range of nanoparticle sizes and shapes were produced which influenced the visual colour of the fabric. The purple samples produced are caused by small particles (<100nm) that have aggregated together. Samples that appear tan or gold in colour have mainly large particles (>500nm) that are either made up of small spheres fused together or are large plates (trigonal, hexagonal); therefore, Mie's laws do not appear to apply. Light coloured samples generally have a few small particles (<100nm) that are spaced out over the fibre surface.</p>

Hot Rolling of the Twin-Roll Cast and Homogenized Mg-6.8Y-2.5Zn (WZ73) Magnesium Alloy Containing LPSO Structures

In this study, hot rolling trials were conducted on a twin-roll cast and homogenized magnesium alloy Mg-6.8Y-2.5Zn (WZ73). The WZ73 contains long period stacking ordered (LPSO) structures due to the ratio of Y and Zn content. Microstructural and texture evolution depending on the different strain and strain rates were investigated, and the resulting mechanical properties were also considered. Therefore, samples were quenched in water directly after hot rolling. The results revealed that the rolling parameters significantly influence dynamic recrystallization (DRX), while continuous and twin-induced dynamic recrystallization are assumed to be the main DRX mechanisms. It was also found that high strains and strain rates are required to proceed the DRX. The resulting textures revealed that the non-basal slip of <a>-dislocations and <c+a>-dislocations is activated during hot rolling. Hot rolling results in increased strength and ductility compared to the initial twin-roll cast and homogenized state.