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1

Characterisation of some generalised continuous distributions by doubly truncated moments

Athar Haseeb, Ahsanullah Mohammad, Ali Mohd. Almech

Operations Research and Decisions

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2023

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Vol. 33, No. 1

1--19

EN

The characterisation of probability distribution plays an important role in statistical studies. There are various methods of characterisation available in the literature. The characterisation using truncated moments limits the observations; hence, researchers may save time and cost. In this paper, the characterisation of three general forms of continuous distributions based on doubly truncated moments has been studied. The results are given simply and explicitly. Further, the results have been applied to some well-known continuous distributions.

2

Exploring the characterization, liberation and flotation response of a Nigerian low-grade copper ore

Nheta Willie, Ola-Omole Omoyemi O.

Journal of Sustainable Mining

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2023

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Vol. 22, iss. 1

20--32

EN

This study explores the characterization, liberation and flotation response of low-grade copper ore from Anka area, Zamfara state Nigeria. The ore was crushed, milled and sieved in accordance with BS 410 standard. It was characterized with XRD, XRF, SEM-EDS and AAS. Froth flotation was carried out with varying %solids, pH, retention time and collector dosages using SEX and sodium oleate. Particle size distribution of the ore shows its economic liberation between -150 and +106 µm while 80% passing corresponds to 175.7 µm using the Gaudin Schuhmann equation. However, according to metallurgical balance calculation, 63 µm proved to have the highest metal content. Identified peaks of the copper ore by XRD revealed the presence of pyrite and chalcopyrite as the major mineral content at 47 and 36%, respectively, while other elements were present in traces. XRF shows Fe and Cu as the major elements and others in traces. Morphology, according to SEM-EDS, revealed that Fe is the major impurity while the presence of Cu and S confirmed chalcopyrite is present in the ore minerals. AAS shows an average of 25.87% Cu and 32% Fe in the ore. Optimum recoveries of copper were recorded at 30% solids, pH of 8, 30 minutes retention time. The highest recovery of 95.94% was recorded with SEX at 0.25 mol/dm3, while recoveries were lower with PAX, the highest recovery being 33% at 0.20 mol/dm3. 0.25 mol/dm3 of SEX recorded the highest yield and enrichment ratio of 40.38 and 2.38, respectively.

3

Adsorbent Characterization from Cocoa Shell Pyrolysis (Theobroma cacao L) and its Application in Mercury Ion Reduction

Nursiah Cut, Desvita Hera, Elviani Elviani, Farida Nurlia, Muslim Abrar, Rosnelly Cut Meurah, Mariana Mariana, Suhendrayatna Suhendrayatna

Journal of Ecological Engineering

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2023

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Vol. 24, nr 6

366--375

EN

In this paper, we describe the characterization and application of adsorbent derived from the pyrolysis of cocoa shells, which is a natural source of adsorbent materials. The adsorbent that was used in this experiment is an environmentally friendly adsorbent that was prepared by the pyrolysis of cocoa shells. For 1.5 hours, the pyrolysis process was carried out at temperatures ranging from 300 to 380 °C. The adsorbent was characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and analysis with an X-ray diffraction (XRD) analyzer. Water-ash content and iodine absorption capacity were also determined in accordance with SNI 06-3730-1995. At a contact time of 90 minutes, the adsorption capacity of mercury ions was found to be 0.106 mg/gram. In this study, the adsorption of mercury ions with the adsorbent followed pseudo-second-order models with an R2 value of 0.9929.

4

Relations for moments of generalised order statistics based on Weibull–G family of distributions

Athar Haseeb, Alharbi Yousef F., Fawzy Mohamad A.

Operations Research and Decisions

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2022

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Vol. 32, No. 4

17--31

EN

The Weibull distribution is one of the important distributions used in reliability theory and life-testing experiments. The generalised versions of the Weibull distribution give a more flexible model for these studies. The Weibull–G family of distributions is one of the extended versions extensively studied. In this paper, we have studied moments properties of generalised order statistics for the said distribution in terms of a single moment, product moments and characterisation. Several examples and special cases are presented. The results can be applied to all distributions belonging to this family.

5

Prospects for using wastewater from a farm for algae cultivation: The case of Eastern Colombia

Urbina-Suarez Nestor Andres, Barajas-Solano Andres Fernando, Garcia-Martinez Janet Bibiana, Lopez-Barrera German Luciano, González-Delgado Angel Dario

Journal of Water and Land Development

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2022

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no. 52

172--179

EN

In recent years, the technical and economic feasibility of using microalgae and cyanobacteria has been explored for the removal and exploitation of domestic, agricultural and industrial residual effluents with high C, N and P compounds content. To contribute to the understanding of the process and its technical viability for microalgae growth, the article discusses monitoring, flow determination, and physicochemical characteristics of two types of effluents generated in an experimental farm located in the east of Colombia, before (R1) and after biological treatment (R2). In general, the results showed the reduction of different parameters, such as total dissolved solids (TDS), hardness, salinity and phosphates after treatment with activated sludge. However, the conductivity value obtained in R1 and R2 showed the presence of a pollutant load. These findings can be attributed to the highest concentration of fats and oils in the water during early hours of the day. Finally, although the concentration of nitrates increased from 46.63 to 225.21 mg∙dm-3 and phosphate decreased slightly from 9.65 to 6.21 mg∙dm-3,no inhibition was generated in the microalgae, as evidenced in the growth of the microalgal biomass in effluents after nitrate and phosphate removal above 80%.

6

Bacterial selection of the Pseudomonas genus with the capacity to treat water and contaminated soils

Escudero-López Henry Joel, Serrano-Carrillo Karla Anabel, Jácome-Pilco Carlos Rodrigo, Sanaguano-Salguero Herminia del Rosario, Bayas-Morejón Isidro Favian

Journal of Water and Land Development

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2022

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no. 53

238--241

EN

In the present work, bacteria of the Pseudomonas genus native to the Ecuadorian Amazon with the capacity to treat contaminated water and soils were selected. For this purpose, 20 soil samples from Amazon region with evidence of contamination were analysed. For identification, each sample was assigned a code according to the sampling area: Joya de los Sachas (S), Minga (M) and Siete de Julio-Shushufindi (SH). The cultures were performed in the combination of Bushnell Hass (BH) + Luria Bertani (LB) and Müeller-Hinton (MH) + Brucella agar (BA) media, all with the addition of diesel to verify their efficacy in the growth of bacteria capable of surviving in contaminated media. The combination with ideal results was that of BH + LB, by means of Gram-staining it was determined that 19 of the samples had interest microorganisms. To characterize the isolates at the species level, biochemical tests of: catalase, citrate, glucose, hemolytic activity and urease were applied, which allowed to confirm the existence of the Pseudomonas of interest. The results indicated that P. stutzeri (in samples S1 and M1), P. aeruginosa (in SH2 and SH5) and P. putida (in S7, S8, S10 and SH4) obtaining a total of 8 isolates (40%) of interest from the initial 19. With the results obtained from this work, an optimal culture method was standardized for the selection of bacteria with potential for treating contaminated soils and water.

7

Optimization of Packing Density of M30 Concrete with Steel Slag as Coarse Aggregate Using Fuzzy Logic

Arivoli M., Malathy R.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 3

1903--1913

EN

Concrete plays a vital role in the design and construction of the infrastructure. To meet the global demand of concrete in future, it is becoming a challenging task to find suitable alternatives to natural aggregates. Steel slag is a by-product of steel making process. The steel slag aggregates are characterized by studying particle size and shape, physical and chemical properties, and mechanical properties as per IS: 2386-1963. The characterization study reveals the better performance of steel slag aggregate over natural coarse aggregate. M30 grade of concrete is designed and natural coarse aggregate is completely replaced by steel slag aggregate. Packing density of aggregates affects the characteristics of concrete. The present paper proposes a fuzzy system for concrete mix proportioning which increases the packing density. The proposed fuzzy system have four sub fuzzy system to arrive compressive strength, water cement ratio, ideal grading curve and free water content for concrete mix proportioning. The results show, the concrete mix proportion of the given fuzzy model agrees with IS method. The comparison of results shows that both proposed fuzzy system and IS method, there is a remarkable increase in compressive strength and bulk density, with increment in the percentage replacement of steel slag.

8

Preparation And Properties Of Bionanocomposite Films Reinforced With Nanocellulose Isolated From Moroccan Alfa Fibres

Benyoussif Y., Aboulhrouz S., El Achaby M., Cherkaoui O., Lallam A., El Bouchti M., Zahouily M.

Autex Research Journal

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2015

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Vol. 15, no. 3

164--172

EN

Nanocellulose (NC) were extracted from the Moroccan Alfa plant (Stipa tenacissima L.) and characterised. These Alfa cellulosic nanoparticles were used as reinforcing phase to prepare bionanocomposite films using carboxymethyl cellulose as matrix. These films were obtained by the casting/evaporation method. The crystallinity of NC was analysed by X-ray diffraction, the dimension of NC by atomic force microscopy, molecular interactions due to incorporation of NC in carboxymethyl cellulose (CMC) matrix were supported by Fourier transforms infrared (FTIR) spectroscopy. The properties of the ensuing bionanocomposite films were investigated using tensile tests, water vapour permeability (WVP) study and thermogravimetric analysis. With the progress of purification treatment of cellulose, the crystallinity is improved compared to the untreated fibres; this can be explained by the disappearance of the amorphous areas in cellulose chain of the plant. Consequently, the tensile modulus and tensile strength of CMC film increased by 60 and 47%, respectively, in the bionanocomposite films with 10 wt% of NC, and decrease by 8.6% for WVP with the same content of NC. The NC obtained from the Moroccan Alfa fibres can be used as a reinforcing agent for the preparation of bionanocomposites, and they have a high potential for the development of completely biodegradable food packaging materials.

9

Objective assessment for characterising the flatness of garment sewing stitches

Jiang H., Liu J., Chai Z., Wang C., Zhang M.

Autex Research Journal

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2013

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Vol. 13, no. 4

110--117

EN

In this paper, a novel classification method of assessing garment sewing stitch based on amended bi-dimensional empirical mode decomposition (ABEMD) has been introduced. Two parameters that characterise garment sewing stitch, average area and standard deviation, have been defined based on the grey value of pixels. Experimental results showed that when the window size is 512×128 pixels with regard to average area, the threshold can be decided as 6.00, 5.50, 5.30 and 4.00 for five different grades , respectively. Meanwhile, with regard to standard deviation, the threshold can be decided as 48.00, 40.00, 30.00 and 20.00, respectively. It is demonstrated that the parameters are effective in discriminating sewing stitch images in terms of the grades when used as inputs for the ABEMD. The performance of the algorithm on different garment status is significantly reliable.

10

Badania nad możliwością zagospodarowania odpadów z procesu flotacji rud cynku i ołowiu

Lipowska B., Wojsa J.

Prace Instytutu Szkła, Ceramiki, Materiałów Ogniotrwałych i Budowlanych

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2008

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R. 1, nr 1

85-92

PL

W pracy podjęto próbę określenia możliwości zestalenia odpadów z procesu flotacji rud cynku i ołowiu z jednoczesnym trwałym związaniem lub usunięciem zawartych w nich szkodliwych związków. Do zestalania wykorzystano własności wiążące składników odpadu: wiązanie za pomocą cementu Sorela oraz proces karbonizacji wodorotlenków wapnia i magnezu. Zestalany odpad poddawano granulacji lub formowano z niego kształtki na prasie hydraulicznej. Najlepsze wyniki uzyskano, formując odpowiednio spreparowany odpad pod ciśnieniem 30 MPa i poddając go działaniu CO2 w podwyższonej temperaturze. Tak zagęszczony materiał wykazuje wytrzymałość na ściskanie nie mniejszą niż 5 MPa i nie ulega rozmywaniu w wodzie. W dodatkowej obróbce termicznej odpadu toksyczne składniki zostają unieszkodliwione poprzez rozkład lub przemiany w formy nierozpuszczalne w wodzie.

EN

The aim of the research presented in this work was to establish the posssibilities of solidyfying waste from the process of zinc and lead ores' flotation with a simultaneous permanent binding or removal of the harmful compounds they contain. Solidifying properties of waste components were used, in particular binding by means of Sorel cement. and the process of calcium and magnesium hydroxides' carbonisation. The solidified waste was subjected to granulation or formed into shapes in hydraulic press. The best results were obtained when the appropriately prepared waste was subjected to pressure of 30 MPa and exposed to CO2 in an increased temperature. So condensed material is characterised by compression strength no lower than 5 MPa and does not wash in water. Owing to additionally applied thermal treatment of waste the toxic components are made harmless through decomposition or transformation into forms insoluble in water.

11

Synthesis and Characterisation of 2,2-Dinitro-1,3-propanediol-based Plasticisers

Ek S., Eldsäter C., Goede P., Holmgren E., Tryman R., Latypov N. V., Raymond Y. G. Y., Wang L. Y.

Central European Journal of Energetic Materials

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2005

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Vol. 2, nr 4

33-45

EN

In this paper, the synthesis of two energetic plasticisers (2,2-dinitro-1,3-bis(2-azido acetoxy) propane and 2,2-dinitro-1 ,3-bis(formyloxy)propane is outlined. The attempted syntheses of even further derivatives are described. The prepared compounds were characterised and evaluated as plasticisers. Their glass transition temperatures are acceptable to excellent, but both of them are thermally unstable.

12

An improved model-based vessel tracking algorithm with application to computed tomography angiography

Bołdak C., Rolland Y., Toumoulin C.

Biocybernetics and Biomedical Engineering

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2003

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Vol. 23, no. 1

41-63

EN

This paper reports newest improvements proposed for the segmentation and the characterisation of three-dimensional vessels observed through Computed Tomography Angiography using geometrical moments. Several adaptive controls are introduced, which allow to deal with pathological patterns such as dense and scaterred calcifications. The reduced time computation makes the algorithm capable to face clinical constraints in routine use. Examples are given on several data sets that highlight critical situations to handle.

13

Założenia kierunkowe Systemu Infrmacji Przestrzennej w Polsce

Bielecka E.

Archiwum Fotogrametrii, Kartografii i Teledetekcji

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2001

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Vol. 11

P-23--P-28

PL

Artykuł przedstawia najważniejsze założenia Systemu Informacji Przestrzennej w Polsce opracowane w trakcie prac nad projektem badawczym zamawianym „ Koncepcja SIP w Polsce ". Projekt zamowiony przez MSWiA realizowany byl przez Instytut Geodezji i Kartografii w kooperacji z Politechniką Warszawską, AGH, Uniwersytetem WarmińskoMazurskim i Uniwersytetem Śląskim vv latach 1998-2001.