Shape Of Distribution Curve Research Articles

Field classification of fractured reservoirs of crystalline basement

Development of oil and gas deposits in fractured reservoirs entails certain risks due to peculiarities of geological structure. Classification and identification of fractures in reservoirs is of high-priority importance and makes it possible to assess the impact of both fractured systems and matrix blocks on field development parameters. This article presents the results of statistical and qualitative analysis of the influence of fracture systems and fracture heterogeneity to classify reservoirs in crystalline basement granitoids using the example of the White Tiger (Bach Ho) and Dragon (Rong) fields located on the southern shelf of the South China Sea (Viet Nam). Field classification of fractured reservoirs is based on a well-marked difference in parameters between wells within a field, due to fracture heterogeneity. In order to solve the tasks set, construction and analysis of graphs of well performance parameters distribution (productivity, flow rates, accumulated indicators, etc.) as well as Lorenz curves were carried out. According to the results, all the objects under study are characterized by asymmetrical shape of distribution curves, which indicates a significant influence of fracturing. Based on the calculated values of the fracture influence coefficient, it is found that fractured reservoirs in crystalline basement, as a first approximation, belong to type 2. This fact is inconsistent with the earlier works on crystalline basement, in which rocks are classified as reservoirs of type 1. Such contradiction is explained by the fact that the microfracture systems and the blocky low-permeability part exhibit matrix properties, but are not fully matrix. This part of the reservoir is proposed to be called a “pseudo-matrix”. If macrocracks dominate in the section, the basement rocks are identified as type 1 fractured reservoirs, but if microfracture systems (“pseudo-matrix”) dominate in some parts of the void space, they may show the properties of type 2 reservoirs forming a mixed type of fractured reservoirs.

Frequency Distribution Analysis of a Maize Population as a Tool in Maize Breeding

The objective of this study was to investigate the distribution of progressive selection generations in order to define the maximum efficiency of increasing yield in relation to the stage of selection procedure. Experimental procedure lasted five years on open-pollinated lines selected in two contrasting environments under low plant population. Mean grain yield of individual maize plants increased by 79% from C0 to C4 generation in environment A and 32% in environment B. Yield of individual plants was increased by 58% from C0 to C2 when selection was fully practiced in environment B. The progressive reduction of CV values through the selection generations revealed gene fixation and lack of segregation in selected lines which tended to be more uniform and homozygous. Low to medium negative kurtosis and low to medium positive skewness, accompanied by a more “squared” shape of distribution curve may indicate more homozygous genetic material that was categorized in clusters of similar C4 lines as was observed in environment A, depicting the end of selection procedure. In C4, a breeder may choose from the upper part of distribution curve (higher yielding plants) in order to avoid possible selection of deleterious genes at the kurtosis-biased lower part of the distribution curve. Our findings suggested the selection of cultivars of narrow adaptation, because at the initial stages of the selection program the effect of environment lead to different genetic materials, favouring certain genotypes. In our study environment B favoured selection procedure for developing high yielding open-pollinated lines for breeding and farming purposes.

Kinetic and thermodynamic analysis of Creosote degradation process under isothermal experimental conditions

Isothermal degradation process of commercial Creosote was analyzed by the thermogravimetric (TG) technique in a nitrogen atmosphere, at four different operating temperatures (230, 250, 270 and 290°C). The kinetic triplet [Ea , A and f(α)] and the thermodynamic parameters (ΔH ≠, ΔS ≠and ΔG ≠) for investigated Creosote samples were calculated. It was found that two-parameter autocatalytic Šesták-Berggren (SB) kinetic model best describes the process, but in the form of accommodation function with phenomenological character. Applying the multiplicative factor, the true value of activation energy (E true a ) was calculated. The experimental density distribution function of the apparent activation energy values was evaluated from isoconversional kinetic analysis. Based of the characteristic shape of distribution curve, it was concluded that the isothermal degradation of Creosote represents a complex physico-chemical process, given the chemical structure of the studied system. It is assumed that the considered process probably includes primary and secondary (autocatalytic) pyrolysis reactions, together with various decomposition reactions and radicals recombination pathways. The objective of the presented work is the proof of principle of the pyrolysis-based thermo-chemical conversion technologies for the production of value-added chemicals from the complex organic compounds, which even include chemical contaminants (such as PAHs). Also, the present work allows us that by using a unified kinetic approach we can obtain a significant physico-chemical characteristics of the tested system, which can then be used in the procedure for the separation of organics from creosote-treated woods and creosote-contaminated soils. The significance of this research is to identify the global kinetic behavior of some target contaminant compounds for pyrolysis, which are primarily PAHs.

Thermal characterization and isothermal kinetic analysis of commercial Creosote decomposition process

Isothermal decomposition process of commercial Creosote was analyzed by thermogravimetric technique in a nitrogen atmosphere, at four different operating temperatures (T = 230, 250, 270, and 290 °C). It was found that the two-parameter autocatalytic Sestak–Berggren kinetic model best describes the investigated process. It was established that the applied logistic function can successfully perform a given kinetic predictions of investigated process, at all operating temperatures. The experimental density distribution function of the apparent activation energy values was evaluated. Based of the characteristic shape of distribution curve, it was concluded that the isothermal pyrolysis of commercial Creosote represent a complex process, which probably includes primary and secondary (autocatalytic) pyrolysis reactions, together with various decomposition reactions and radicals recombination pathways.

Statistical analysis of factors affecting the spatial variability of annual minimum flow characteristics in a cold temperate continental region (southern Québec, Canada)

We have analyzed relationships between environmental factors (physiographic, climatic, geological, geographic and land use) and extreme minimum flow characteristics. We have defined 18 hydrological variables on the annual minimum flow series according to the natural flow regime paradigm. Application of the principal component analysis (PCA) to these 18 variables allowed us to extract five principal components, each associated with a fundamental characteristic (magnitude-frequency, timing, inter-annual variability of magnitude and timing, shape of distribution curve) of the annual minimum flows. The analysis of indices and values of the loading of the five PC revealed a spatial difference in the annual minimum flow characteristics between stations on the north and south shores of the St. Lawrence River (Quebec, Canada). South shore stations are generally characterized by lower magnitude, later timing, and sharper inter-annual variability of magnitude and timing of the annual minimum flows than those on the north shore. The analysis of correlations (simple correlation and canonical correlation) between the five hydrological PC and the seven environmental PC, also extracted by means of the PCA, revealed that the spatial difference between the annual minimum flow characteristics observed between the north and the south shore stations is mainly due to precipitation (climatic factor) based on a highly complex relationship, which mainly involves the timing of annual minimum flows.

The shape of the distribution curve: an indication of changes in the journal productivity distribution pattern

Discussed is the effect of changes in the internal structure of data on the shape of the journal productivity distribution curve. The presupposed sensitivity of the curve shape to the concentration/dispersal disparity is investigated by dividing a data set into a few subsets. Distinct relationship between the S-shaped curve and the higher concentration effect is recognised.

Angular distribution of flux at the exit of cylindrical tubes

Integration of elementary fluxes of molecules crossing the entrance and scattered from tube walls in molecular flow was undertaken. Results, which were verified with Monte Carlo simulation procedure, show variation of angular distribution in an exit, i.e., the shapes of distribution curves are no longer the same in different zones of the exit surface. These results characterize the cylindrical tube as a molecular source better than results from previous papers calculated for targets placed at some distance from the exit of the tube.

Laser Diffraction Spectrometers/Experience in Particle Size Analysis

AbstractOver the past few years, laser diffraction spectrometry has become a very important method of particle size analysis. Typical features include the large measuring range, the simplicity of operation and the speed with which analyses can be carried out. The principle of measurement and the set‐up of three commerical instruments are described.The following points are discussed, with reference to examples:–Relevant parameters, such as particle shape, shape of distribution curve or dispersion, bution curve or dispersion,–reproducibility, comparison of the results obtained with different types of apparatus between one another and with other, analytical methods, and–on‐line use of the instruments for the measurement of dynamic processes, eg. flocculation and dispersion processes.Operating experience gained with six instruments over a number of years is discussed.The measuring method which is described here is in a stage of rapid development and dissemination. It is for this reason that recent improvements and new developments cannot be dealt with here. For example, an apparatus named Helos from Sympatec GmbH, Remlingen, has appeared on the market. The external appearance of the instruments marketed by the Malvern and Leeds and Northrup companies has changed somewhat.The author's practical experience (in some instances extremely wide‐ranging) with these devices is presented here in summary form.

Distribution des terres rares et de quelques éléments en trace dans les sédiments récents des fosses de la Mer Rouge

Sediments of three cores in Atlantis II and Chain deeps of Red Sea were analysed for rare earths elements (REE) and other trace elements (Th, Hf, Sr, Cs, Ta, …) by neutron activation. REE, and Ta, Cs and Th contents are excessively low (average REE ≅ 20 ppm). The chondritic normalization curves show an enrichment in light REE and excess Eu content (Eu/Sm ratio from 0.25 to 0.75) in several samples. Two hypotheses are discussed: the nature of parent rocks of these sediments and the physico-chemical conditions of sedimentation especially complexation and oxydo-reduction phenomenons. Sedimentation environment could not induce trace elements distribution. On the other hand, the very low concentrations, the general shape of distribution curves and the excess Eu content are quite similar to those observed in ultrabasic rocks. Thus, these sediments seem to have been deposited after deep hydrothermal alteration of ultrabasic rocks like peridotite.

Some Fundamental Factors in Quantitative Analysis by Ion Microanalyzer

In analysis of hydrogen in metals and alloys by SIMS, control of the hydrogen blank mainly due to residual gases is a persistent problem. Contrarily, this problem becomes less important in case of deuterium analysis. The prescribed amounts of deuterium were introduced into a pure titanium and a beta-titanium alloy (Ti-6.6wt%Fe) by the gas reaction method. Intensities of the various secondary ions sputtered from each sample were measured by the Hitachi Ion Microanalyzer with primary ions of Ar+. Energy distributions of the various secondary ion species were measured with the energy window of about15eV width. The effects of oxygen gas pressure in the target chamber and the bulk deuterium concentrations on the shape of energy distribution curves are discussed. For all samples, intensity of D- ions is higher than that of D+ ions, especially at higher energy ranges. With increasing the deuterium concentration: a) intensities of D+and D- ions from Ti-D system increased, but their shape of distribution curves remained unchanged. b) not only the intensities but also their shape of distribution curves of D- ions from Ti-6.6%Fe-D system varied, but no change was observed in the shape of the curve of D+ ions. The change in the intensities was more remarkable at the higher energy range. By setting the position of energy window at higher energy range, the linearity increased on the relation between the intensity of D- ions and the bulk deuterium concentration for Ti-6.6%Fe-D system. Intensity and shape of the energy distribution curve of Ti+, TiO+ and O+ ions, respectively, ejected from a titanium dioxide (rutile) are compared with those measured on a pure titanium with introduction of oxygen gas into the target chamber; origin of the ion species observed is briefly discussed.

Cross-sections for the formation of Sb and Sc isotopes by irradiation of Y, La, Ta, and Au with 18·2 GeV protons

The cross-sections have been measured for several Sb and Sc isotopes produced by irradiation of yttrium (Sc only), lanthanum, tantalum, and gold with 18·2 GeV protons. The shapes of the yield distribution curves for both Sb and Sc isotopes vary with the target element. If the previously known yield distributions with uranium as targets are decomposed into a “spallation” part and a fission part, the former will in both cases be about equal to the distribution with gold or tantalum as the target, whilst in shape the fission part closely resembles the distributions obtained when uranium is irradiated with 570–590 MeV protons. From the variation in shape of the distribution curves with target, this procedure of decomposition seems less justified for the scandium isotopes than for antimony isotopes. The high spin to low spin isomeric yield ratios of the 44Sc isomers were also determined, and show a very definite increase with mass difference between target and product.

Analysis of field effect transistors with arbitrary charge distribution

Solutions of field effect equations in which carrier density and space-charge distributions are considered in general form show that the LF terminal characteristics are not strongly dependent on the shape of the distribution curves. General expressions for mutual transconductance, output conductance, junction capacitance and current amplification are derived as functions of the depletion layer thickness at the device boundaries. These expressions are not explicitly dependent on charge distribution. Relationships between the small-signal and dc terminal characteristics depend on the shape of the charge distribution curves but cannot be varied by more than a factor of two. The shape of the device is shown to have secondary importance.

インフルエンザウイルスの“不完全粒子”

The morphological characteristics of the virus from standard passage, undiluted passage and the 106 EID50 inoculation were compared with each other.In chorioallantoic fluid, in cases in which the EID50/HA ratio is higher than 106 (equal to standard passage), the diameter of the virus particles is constant, its distribution is normal and the width of the distribution is narrow. When the EID50/HA ratio is low, where the presence of the incomplete form is dominant, the width of the distribution of the particle diameter is wide and the form of the distribution curve is skew.In any condition of inoculations, many small sized particles are found in extracts of chorioallantoic fluid differently from the case of the chorioallantoic fluid. This finding is especially manifest in the case having low EID50/HA ratio.As these results, the author classifies the incomplete particles into three types:1. Irregulary shaped particles larger than 120 millimicron.2. Spherical particles which cannot be distinguished with complete particles, ranging 110-120 millimicron.3. Irregularly shaped, small size particle smaller than 100 millimicron, maninly found in chorioallantoic membrane.From the shape of distribution curve of the particle diameter and EID50/HA ratio, the author considers the type 1 particle as the true incomplete form and the type 3 as immature form. The type 2 particles cannot yet be interpreted.

インフルエンザウイルスの“不完全粒子”

The morphological characteristics of the virus from standard passage, undiluted passage and the 106 EID50 inoculation were compared with each other.In chorioallantoic fluid, in cases in which the EID50/HA ratio is higher than 106 (equal to standard passage), the diameter of the virus particles is constant, its distribution is normal and the width of the distribution is narrow. When the EID50/HA ratio is low, where the presence of the incomplete form is dominant, the width of the distribution of the particle diameter is wide and the form of the distribution curve is skew.In any condition of inoculations, many small sized particles are found in extracts of chorioallantoic fluid differently from the case of the chorioallantoic fluid. This finding is especially manifest in the case having low EID50/HA ratio.As these results, the author classifies the incomplete particles into three types:1. Irregulary shaped particles larger than 120 millimicron.2. Spherical particles which cannot be distinguished with complete particles, ranging 110-120 millimicron.3. Irregularly shaped, small size particle smaller than 100 millimicron, maninly found in chorioallantoic membrane.From the shape of distribution curve of the particle diameter and EID50/HA ratio, the author considers the type 1 particle as the true incomplete form and the type 3 as immature form. The type 2 particles cannot yet be interpreted.