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Morphometric analysis of pebbles in verification of transport processes and interpretation of palaeoenvironment: A case study from the Ogwashi Formation (Oligocene), Niger Delta Basin, Nigeria

Ogbe Ovie B., Osokpor Jerry, Emelue Chukwunomso V., Ocheli Azuka

Geologos

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2023

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Vol. 29, No. 1

21--31

EN

The present paper discusses a palaeoenvironmental interpretation of the Oligocene Ogwashi Formation (Niger Delta Basin, Nigeria) through morphometric analysis of pebbles, a research method essentially depending on the quantitative evaluation of pebble size and shape which change during transport processes in a range of depositional environments. The relationship of bivariate and ternary-diagram plots of independent functions was determined from freshly exposed sandstone sections in quarries at Ibusa, near Asaba, Nigeria. The grain size of pebbles ranges from fine (11.00 mm) to very coarse (41.33 mm), with a mean size of 21.05 mm (coarse pebbles). A bivariate plot of the flatness index vs maximum projection sphericity index shows 37% of the pebbles to fall within a beach (marine) environment, and 33% within a fluvial environment; the remaining 30% are uncertain. The maximum projection sphericity index vs oblate-prolate index bivariate plot indicates that 47% of pebbles fall within a marine environment and 22% within a fluvial environment, while the remaining 31% are uncertain. The sphericity-form ternary diagram plot shows that the pebbles primarily comprise bladed, platy, very bladed and very platy of near-equal proportions with minor elongate and very elongate stones, which suggests that the pebbles are diverse in origin. The sphericity-form bivariate plot indicates that the pebbles are largely of disc and blade shapes with a minor number of spherical and rod shapes. The near-equal proportion of pebbles in different segments of the bivariate and ternary diagram plots, and the wide distribution of the pebble grain sizes and shapes suggest the Ogwashi Formation is composed of redeposited sediments that likely were transported and deposited in a mix of marine and fluvial settings with possible transitional environments. In other words, the pebbles can be interpreted as marine-influenced fluvial sediments in marginal-marine settings.

2

Investigation of particle size distribution of grinded amber by electropulse discharges in a liquid medium

Chornyi Valentyn, Kharchenko Yevhen, Mysiura Taras, Popova Nataliia, Zavialov Volodymyr

Archive of Mechanical Engineering

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2021

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LXVIII, nr 3

337--348

EN

The article presents the study results of electropulse grinding of amber in aqueous and alcoholic media at different amounts of supplied energy. Description of the electropulse grinding laboratory installation, the mechanism of the destruction process of amber particles and methods of statistical processing of experimental data are given. It was established that alcohol medium has a greater impact on the efficiency of crushing than water. Thus, under the same conditions of energy supply, in the aqueous medium the weighted average particle size of amber was 601:6±688:9 μm, and in an alcohol medium – 368:0±269:6 μm. In an aqueous medium, the particle size decreased to 1/13.6 of raw sample, and in an alcoholic medium to 1/22.3 of raw sample compared to the initial size of raw amber. We found that in the aqueous medium the ratio of large to small fractions is mainly the same with the coefficient of alignment of particles with a size of 1.09. In an alcoholic medium, this ratio significantly differs, with the coefficient of alignment of amber particles of a size of 1.67 with the amount of supplied energy of 125 kJ.

3

Separacja proszków węglowych o dużym stopniu rozproszenia za pomocą metody tryboelektrycznej

Chabecki Piotr, Bordun Ihor, Ivashchyshyn Fedir

Przegląd Elektrotechniczny

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2019

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R. 95, nr 1

81--84

PL

W artykule zostały przeanalizowane warunki rozdzielenia materiałów węglowych za pomocą metody tryboelektrycznej. Została opracowana konstrukcja i wykonane urządzenie powietrznej separacji tryboelektrycznej z oddzielaczem bębnowym. W drodze eksperymentu ustalono, że zastosowanie wibracji podczas podawania proszku do bębna oraz obróbka cieplna proszków istotnie wpływa na wartość tryboładunków. W celu uzyskania dobrego wyniku rozdzielenia materiałów węglowych konieczne jest osuszenie. Materiał osusza się w temperaturze 100 – 120 оС. Otrzymane za pomocą separacji frakcje węglowe zastosowano do budowy superkondensatorów. Określono pojemność właściwą. Ustalono, że największą pojemność właściwą posiada materiał zawierający cząstki o wymiarach 1-10 μm.

EN

The article deals with conditions for carbon materials separation by triboelectric method. A triboelectric air separation device with a drum separator was designed and constructed. It was proved by experimentation that use of vibrations during the powder’s entry into the drum and thermal treatment has a significant effect on the tribocharge value. To achieve good results of carbon material separation, drying is required. The material is dried at 100о-120оC. The carbon fractions acquired by separation were used in construction of ultracapacitors. Specific capacitance was established; with the highest capacitance achieved by material containing particles in 1-10 μm size range.

4

Shear waves in elastic medium with void pores welded between vertically inhomogeneous and anisotropic magnetoelastic semi-infinite media

Gupta S., Ahmed M., Pramanik A.

Acta Geophysica

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2017

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Vol. 65, no. 1

139--149

EN

The paper intends to study the propagation of horizontally polarized shear waves in an elastic medium with void pores constrained between a vertically inhomogeneous and an anisotropic magnetoelastic semi-infinite media. Elasto-dynamical equations of elastic medium with void pores and magnetoelastic solid have been employed to investigate the shear wave propagation in the proposed three-layered earth model. Method of separation of variables has been incorporated to deduce the dispersion relation. All possible special cases have been envisaged and they fairly comply with the corresponding results for classical cases. The role of inhomogeneity parameter, thickness of layer, angle with which the wave crosses the magnetic field and anisotropic magnetoelastic coupling parameter for three different materials has been elucidated and represented by graphs using MATHEMATICA.

5

Środki techniczne ochrony zbiorowej ograniczające skutki zapylenia

Małecki Z. J., Małecka I., Moga M.

Zeszyty Naukowe. Inżynieria Lądowa i Wodna w Kształtowaniu Środowiska

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2012

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Nr 5-6

47-53

PL

Pyły występują w wielu środowiskach pracy i nawet przy niskich stężeniach mogą wykazywać szkodliwe działanie na organizm ludzki. W powietrzu unoszą się różne rodzaje cząstek pyłów, które powstają w następstwie procesów naturalnych i sztucznych (technologicznych). Oceniając szkodliwość pyłów, najbardziej szkodliwa jest frakcja respirabilna mająca największe znaczenie w patogenezie pyłu, która dociera do pęcherzyków płucnych. W pomieszczeniach, w których występuje znaczny stopień zanieczyszczenia pyłami, parami oraz zjonizowanym powietrzem i zapachami pochodzącymi z procesów technologicznych wymagany jest 100% udział powietrza zewnętrznego (świeżego).

EN

Dust is present in many working environments and even at low concentration it may be harmful to the human body. Various kinds of dust particles, which hover in the air, form as a result of natural and artificial (technological) processes. When evaluating dust harmfulness, the most hazardous is a respirable fraction which plays the most important role in dust pathogenesis which reaches pulmonary alveoli. Rooms with a significant degree of contamination of dust, vapour and ionized air and odours coming from technological processes require 100% external (fresh) air.

6

Wybrane właściwości fizykochemiczne pyłów powstających w procesie technologicznym Huty Cynku MIASTECZKO ŚLĄSKIE S.A.

Melaniuk-Wolny E., Nowińska K.

Rudy i Metale Nieżelazne

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2009

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R. 54, nr 1

3-9

PL

Zanieczyszczenia pyłowe hutnictwa cynkowego ze względu na znaczne zawartości w nich metali ciężkich, mogą w zasadniczy sposób negatywnie oddziaływać na poszczególne komponenty środowiska. Dlatego istotne jest poznanie ich właściwości fizykochemicznych. W pracy przedstawiono wyniki badań dotyczące składu ziarnowego, morfologii ziaren pyłów pochodzących z procesu technologicznego Huty Cynku MIASTECZKO ŚLĄSKIE S.A. w powiązaniu z ich składem fazowym. Stwierdzono, że analizowane pyły charakteryzują się dużą różnorodnością właściwości fizykochemicznych, uwarunkowaną źródłem ich powstawania.

EN

Environmental nuisance of Zinc and Lead metallurgy presently results mainly from formation of large ammount of rich in heavy metals fine grained dusts in zinc plants. Emission of these dusts may impact on particular environment components and cause serious health effects, therefore the knowledge of fraction, chemical and mineral constitution is very important. The paper presents research findings of fraction, chemical and mineral constitution analysis of dusts stopped in cloth filters of main technological Zinc Plant MIASTECZKO ŚLĄSKIE S.A. departments. The following dusts were analyzed: dust No. 1 (cloth filter type FT 12R), dust No. 2 (cloth filter type FT 12), dust No. 3 (cloth filter type FT 24)- from Sintering Department; dust No. 4 (cloth filter type FT 21) - from Furnace Shaft Department, dust No. 5 (cloth filter type FT 10)- from Lead Refining Department. Fraction constitution researches were made on the basis of numerical fraction constitution analysis by the use of Fraction Constitution Laser Analyser type Analysette 22 produced by Fritsch. Principle of operation of his analyser is based on Fraunhofer diffraction effect He-Ne laser-beam. Identification of dusts phase constitution and dusts grains morphology were made by the X-ray microanalysis method using X-ray microanalyser JCXA 733 produced by Joe, equipped with IBIS 30 energy-dispersion spectrometer produced by Oxford Instruments. This measurement allowed getting information about qualitative and quantitative elemental constitution in separate micro-area. On the basis of the studies it was shown that analyzed dusts are characterized by high variety of fraction, chemical and mineral constitution. This high variety depends on the mechanism of dust release i.e. on the conditions in which the technological process was carried out and composition of the raw materials processed. Dusts No. 1, 2, 3 stopped in cloth filters of Sintering Department, fordem during mechanical process of sinter crushing, consist mainly of 20-60 micro/m diameters grains, which are chemical homogeneus: ZnO, PbSO4 (dusts 1, 2) and ZnS, PbS (dust 3). The dust No. 3 contains also grains, consisted of conglomerates formed during thermal alterations, as well as small, below 2.5 micro/m diameters, spherical particles, consisted mainly of PbSO4 and PbS. Numerous small condense grains were identified in dusts 4 and 5, formed during evaporation and condensation of metal vapours and their coumponds (oxides and sulfides). This grains are mainly consist of: ZnO, PbO x SiO2, PbSO4 (dust 4) oraz ZnO, sulfides of Pb and Zn, As2O3 (dust 5). Results of investigations, complemented by chosen heavy metals bio-accessibility, may be useful in determination of their mobility in environment, and be the basis of making an assessment of noxiousness of dusts emitted from Zinc Plant MIASTECZKO ŚLĄSKIE S.A.

7

Przedział ufności dla frakcji

Zieliński R.

Matematyka Stosowana : matematyka dla społeczeństwa

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2009

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T. 10/51

51-67

EN

Confidence intervals have been invented by Jerzy Spława-Neyman in 1934 (J.Neyman, Journal of the Royal Statistical Society, Vol. 97, No.4. (1934), pp. 558-625). To apply the theory to the binomial case some nomograms or vast tables were needed (C.J.Clopper and E.S.Pearson: Biometrika, Vol. 26, No.4 (Dec.,1934), pp. 404-413) which made the idea far from practical use. An easy to present and motivate and easy to compute remedy was to replace the binomial distribution by its normal approximation; the solution is currently in near universal use. Due to inadequate coverage probability many other alternative intervals have been recommended: an exhaustive and up to date review with a discussion one can find in L.D.Brown, T.T.Cai and A. DasGupta: Statistical Science 2001, Vol. 16, No.2, 101-133. We address the problem in the context of Polish textbooks.

PL

Przedziały ufności zostały wymyślone przez Jerzego Spławę-Neymana w 1934 [15]. Praktyczne zastosowanie teorii Neymana do przedziałowej estymacji prawdopodobieństwa sukcesu w schemacie Bernoulliego (parametru rozkładu dwumianowego) stwarzało jednak pewne trudności zarówno jeśli chodzi o ich konstrukcję (rozkład dyskretny!), jak i o ich numeryczne obliczanie. Jako panaceum wymyślono asymptotyczne przedziały ufności oparte na przybliżaniu rozkładu dwumianowego rozkładem normalnym: konstrukcja i rachunki stają się bardzo proste. Kłopot polega na tym, że w przypadku skończonej próby pojawiają się wtedy trudności z wyznaczeniem przedziału ufności na postulowanym poziomie ufności. Obecnie powszechny dostęp do komputerów i licznych prostych kalkulatorów "kieszonkowych" z funkcjami statystycznymi umożliwia łatwą realizację dokładnych konstrukcji Neymana.

8

Estymacja frakcji

Zieliński R.

Matematyka Stosowana : matematyka dla społeczeństwa

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2008

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Nr 9

76-90

PL

W populacji składającej się z N elementów jest nieznana liczba M elementów wyróżnionych. W artykule w przystępny sposób prezentuję różne problemy związane z estymacją frakcji θ= M/N.

EN

A population of N elements contains an unknown number M of marked units. Problems of estimating the fraction θ = M/N are discussed. The well known standard solution is θ= K/n which is the uniformly minimum variance unbiased estimator, maximum likelihood estimator, estimator obtained by the method of moments, and in consequence it shares all advantages of such estimators. In the paper some versions of the estimator are considered which are more adequate in real situations. If we know in advance that the unknown fraction lies in a given interval (t1, t2) and we consider an estimator θ1 as better than the estimator θ2 if the average of its mean square error is smaller on that interval, then the optimal estimator is given by (3). The values of the estimator for (t1, t2) = (0, 0.5) and for (t1, t2) = (0.3, 0.4) in a sample of size n = 10 if the number of marked units in the sample equals K, are given in the table TABELKA and the mean square errors of these estimator, versus the error of the standard estimator θ = K/n are presented in Rys. 2. Averaging the mean square error with a weight function, for example such as in Rys.3, gives us the Bayesian estimator with the mean square error like in Rys. 4 (for n = 10). If in some real situations we are interested in minimizing the mean square error "in the worst possible case", the adequate is the minimax estimator. Another situation appears if the population can be divided in some more homogenous subpopulations, for example in two subpopulations with fractions of marked units close to zero or close to one in each of them. Then stratified sampling is more effective; then the mean square error of estimation may be significantly reduced. In the paper the problem of randomized responses is also presented, very shortly and elementarily. The problem arises if a unit in the sample can not be for sure recognized as "marked"or "not marked" and that can be done with some probability only. The situation is typical for survey interview: it allows respondents to respond to sensitive issues (such as criminal behavior or sexuality) while remaining confidential. The final section of the paper is devoted to some remarks concerning the confidence intervals for the fraction. The exact optimal solution is well known for mathematicians but it is probably not very easy for statistical practitioners to follow all theoretical details, and typically confidence interval based on asymptotic approximation of the binomial distribution by a normal distribution are used. That is neither sufficiently exact nor correct. The proper and exact solution is given by quantiles of a suitable Beta distribution which are easily computable in typical statistical and mathematical computer packages.