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1

The Influence of Structural Parameters of Georgian Natural and Modified Mordenite over its Adsorption Properties Towards Lead Ions

Gagniashvili Nino, Akhalbedashvili Lali

Journal of Ecological Engineering

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2023

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Vol. 24, nr 9

130--138

EN

The potential of Georgian natural Mordenite has been studied as a low-cost, eco-friendly adsorbent for the removal of lead (II) ions from aqueous solutions in various experimental environments. The natural and modified Mordenite structural characterization was carried out using XRD, SEM-EDS, XRF, methods. The following parameters were studied for adsorption: dependence of solution pH, adsorbent dose, and initial concentration of lead (II) ions. The results of the optimization study showed that a high dose of adsorbent and a low concentration of Pb (II) ion increase the sorption. The optimum pH was found to be 6-8. Sorption capacity increased along with pH. Langmuir and Freundlich isotherms were used to model the adsorption data. Correlation coefficient values (R2) were 0.975 and 0.922, respectively. Isotherm studies showed that the uptake equilibrium is best described by the Langmuir adsorption isotherm. The maximum sorption capacity was found to be 11.439 mg/g. The research results showed that natural Georgian Mordenite can be used to remove Pb (II) ions from aqueous solutions.

2

A Mini-Review on Thin-Film Composite Hollow Fiber Membranes for Forward Osmosis Applications

Al-Musawy Wafaa Kh., Al-Furaiji Mustafa H., Aljumaily Mustafa Mohammed, Rashid Khalid T., Salih Hussein G., Alsalhy Qusay F., Majdi Hasan Sh., Figoli Alberto

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 1

287--301

EN

Forward osmosis (FO) is an emerging technology that has been extensively studied in the last decade as an efficient method for desalination and water treatment. FO presents many benefits over traditional desalination technologies such as reverse osmosis and distillation. Nevertheless, there are many decisive challenges; the great significance one is the new modification and advances in the preparation of the TFC membranes that must be achieved to enhance the FO performance. Therefore, preparing a suitable TFC membrane with a low structural parameter, low tortuosity, and high porosity are preferred in preparing the TFC membranes to get higher water flux and lower salt flux. This paper reviewed the recent development and advances in using TFC hollow fiber membranes in FO applications. Within that, the most widely applied monomers to prepare the thin polyamide layer (PA) in TFC membranes and the additives that are added during the preparation of the PA layer and their effect on the performance of the TFC membranes have been discussed. Moreover, an effort is made to generate a TFC membrane properties and performance trend according to the results of the water permeate flux and reverse salt flux of the modified TFC FO membranes and the future perspectives and concluding remarks on the FO membrane are evaluated.

3

Outline of the method for prediction of lifetime achieved by ayionic hydraulic drives operated under real field conditions

Ułanowicz L.

Journal of KONES

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2009

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Vol. 16, No. 2

473-484

EN

The presented approach to predict lifetime of avionic hydraulic drives belongs to a priori (accelerated) methods as by its nature it does not reeuire to continue tests until a hydraulic subassembly or drive reaches its boundary value of a structural parameter. The method uses distributions of a random variable with time-dependent variance as models for lifetime prediction. Variations of structural parameters over a discretional period of time are described with use of the Gaussian distribution with the assumption that the course of the process when the structural parameters are subject to deterioration comprises the entire probabilistic characteristic that defines resistance of the hydraulic drive to a wear and tear process. In that context distributions of characteristics for variations of structural parameters were determined for a selected period of time and it served as a basis to find out parameters for the distribution of the defect-free operation time. The completed functional and design decomposition of an example avionic hydraulic drive made it possible to obtain a hierarchical description of the hydraulic drive, to identify its structural parameters that are available during the drive operation as well as to define a set of measurable out put parameters of a system, a module (a hydraulic system) and a block (a hydraulic subassembly). The set of measurable output parameters attributable to the hydraulic system in question is described with use of mathematic equations that result from fundamental equations for hydraulic systems dynamics, i.e. the mass conservation law, the principle of momentum and angular momentum conservation as well as the energy conservation law.

4

Wpływ szybkości chłodzenia na strukturę siluminu AlSi7Mg0,3

Orłowicz W., Tupaj M., Mróz M.

Archiwum Odlewnictwa

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2006

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R. 6, nr 18/1

125--130

PL

Praca dotyczy oceny wpływu szybkości chłodzenia produkcyjnego stopu AlSi7Mg na mikrostrukturę i zwartość odlewu. Badania wykonano na odlewach klinów z ochładzalnikiem. Stwierdzono, że wzrost szybkości chłodzenia pozwala na zmniejszenie wartości parametru strukturalnego λ2D – odległości pomiędzy gałęziami drugiego rzędu dendrytów fazy α(Al) oraz redukcję porowatości stopu.

EN

The effect of the cooling rate of the AlSi7Mg production alloy on casting microstructure and its compactness is assessed. Tests were carried out on wedge shaped castings with chills. The raising of alloy cooling rate was found to permit a reduction of the structural parameter, λ2D – spacing between secondary dendrite branches in α(Al) phase, as well as the reduction of alloy porosity.

5

Wpływ modyfikacji sodem lub strontem na mikrostrukturę i właściwości mechniczne stopu AlSi7Mg

Orłowicz W., Mróz M., Tupaj M.

Archiwum Odlewnictwa

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2006

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R. 6, nr 18/1

117--124

PL

W pracy przedstawiono wyniki badań wpływu modyfikacji tytanem (0,140%Ti), borem (0,002%B) i sodem (0,010%Na, 0,020%Na) lub strontem (0,015%Sr, 0,060%Sr) na indeks gęstości i właściwości mechaniczne (Rm, R0,2, A5) stopu AlSi7Mg, odlanego do formy metalowej. Wzrostowi zawartości sodu od 0,010% do 0,020% Na lub strontu od 0,015% do 0,060% Sr towarzyszy wzrost wielkości wydzieleń krzemu eutektycznego 1max i wzrost odległości pomiędzy wydzieleniami krzemu w eutektyce λE. Stwierdzono, że wraz ze wzrostem zawartości sodu lub strontu rośnie indeks gęstości stopu (porowatość). Efektem zmniejszenia porowatości stopu oraz zmniejszenia wielkości wydzieleń krzemu oraz odległości pomiędzy wydzieleniami krzemu w eutektyce jest wzrost właściwości mechanicznych stopu.

EN

Results of the effect of modification with titanium (0.14%Ti), boron (0.002%B) and sodium (0.010%Na, 0.020%Na) or strontium (0.015%Sr, 0.060%Sr) on the density index and mechanical properties (Rm, R0.2, A5) of the AlSi7Mg alloy cast to metal molds/dies are presented. Increased content of sodium, from 0.010% to 0.020% of Na or strontium from 0.015% to 0.060% Sr, is accompanied by the growth of the size of eutectic silicon precipitates, 1max, and the growth of spacing between silicon precipitates in the λE eutectic. The density index of the alloy (porosity) was found to grow with increased content of sodium or strontium. The effect of the reduced porosity of the alloy, as well as that of the reduced size of precipitates and distances between silicon precipitates in the eutectic, is better mechanical properties of the alloy.

6

Wpływ modyfikacji i temperatury formy na właściwości mechniczne stopu AlSi7Mg

Orłowicz W., Mróz M., Tupaj M.

Archiwum Odlewnictwa

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2006

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R. 6, nr 18/1

109--116

PL

W pracy przedstawiono wyniki badań wpływu modyfikacji tytanem (0,140%), borem (0,002%) i sodem (0,005%, 0,010%, 0,015%, 0,020%) lub strontem (0,015%, 0,040%, 0,060%) oraz temperatury formy (420ºC, 450ºC lub 470ºC) i obróbki cieplnej (przesycanie 535ºC/5h/woda, starzenie 175ºC/5h/powietrze) na wytrzymałość na rozciąganie, umowną granicę plastyczności i twardość stopu AlSi7Mg. Najwyższe wartości Rm, R0.2 i HB uzyskano dla stopu zawierającego 0,010% sodu lub 0,015% strontu, odlanego do formy o temperaturze 420ºC, a następnie obrobionego cieplnie (przesyconego i starzonego).

EN

Results of the effect of modification with titanium (0.140%Ti), boron (0.002%B) and sodium (0.005%, 0.010%, 0.015%, 0.020%) or strontium (0.015%, 0.040%, 0.060%), as well as that of mold/die temperature (420ºC, 450ºC or 470ºC) and heat treatment (solution heat treatment at 535ºC/5h/water, aging at 175ºC/5h/air) on mechanical properties of the AlSi7Mg alloy are presented. The highest values of Rm, R0.2and HB were achieved for the alloy containing 0.010% of sodium or 0.015% of strontium, cast into dies having a temperature of 420ºC, and then heat treated (solution heat treatment and aging).

7

Wykorzystanie łuku elektrycznego do kształtowania struktury i geometrii nadtopień na odlewach ze stopu Al-Si

Orłowicz A. W., Mróz M.

Archiwum Odlewnictwa

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2003

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R. 3, nr 10

81--87

PL

Na odlewach płytek ze stopu AK 7 wykonano metodą GTAW nadtopienia z prędkością skanowania łukiem elektrycznym w zakresie od 0,33 do 1,33 cm/s. Określono geometrię nadtopień oraz wartość parametru strukturalnego λ2D dendrytów fazy α oraz λE eutektyki α+β, a także zmierzono mikrotwardość. Dla uzyskanego zbioru danych określono związki pomiędzy parametrami technologicznymi procesu GTAW, a geometrią nadtopień, strukturą i mikrotwardością obszaru uszlachetnionego drogą szybkiej krystalizacji.

EN

On plate castings of AK 7 (LM 25) alloy the surface fusions were performed by GTAW surfacing process at electric arc scanning speeds from 0.33 to 1.33 cm/s. A penetration geometry and value of structural parameter λ2D of matrix dendrites and λE of the α+ß eutectic were investigated as well as a microhardness was measured. For the obtained data set the relationships between GTAW process parameters and those of penetration geometry, structure and microhardness of the area improved by rapid solidification were estimated.

8

Analityczne zależności pomiędzy warunkami krzepnięcia stopów aluminium, a własnościami mechanicznymi i parametrami struktury

Hajkowski M.

Archiwum Odlewnictwa

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2003

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R. 3, nr 9

162--173

PL

W pracy przedstawiono wyniki badań nad określeniem analitycznych zależności między właściwościami mechanicznymi odlewów a parametrami struktury i warunkami krzepnięcia (gradient temperatury, kąt nachylenia gradientu temperatury względem osi walca). Badano warunki krzepnięcia za pomocą symulacji i doświadczalnie. Określono jakim zbiorem danych z odlewów (stopy, jakość metalurgiczna, warunki krzepnięcia) należy uczyć sieci neuronowe.

EN

The paper presents results of the research aimed at determining analytical relationships between mechanical properties of the castings, their structural parameters, and solidification conditions (temperature gradient, slope angle of temperature gradient with respect to cylinder axis). Solidification conditions were examined with simulation methods and experimentally. It was determined what casting related data file (alloys, metallurgic quality, solidification conditions) should be used for teaching of neural network.

9

Dendritic microstructures in cast Al-Si alloys - an analysis of dispersion factors

Warmuzek M.

Prace Instytutu Odlewnictwa

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1998

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R. 48, z. 1-2

55-73

EN

The methods to evaluate the degree of dendritic structure dispersion in hypoeutectic Al-Si alloys were examined. The technique of direct measurement of dendrite arm and axis spacing was discussed and some criteria of the choice of stereological parameters used as a measure of this spacing were described. The results of measurements of the secondary dendrite arm spacing lambda2 and of the mean chord length and dendrite axis spacing were quoted. A statistical analysis of the results was made and some relationships exiting between the measured structural parametres were derived.

PL

W pracy przeanalizowano metody oceny stopnia dyspersji struktury dendrytycznej w podeutektycznych stopach Al-Si. Omówiono metodę bezpośredniego pomiaru odległości ramion i osi dendrytów oraz kryteria doboru parametrów stereologicznych, stosowanych jako ich miara. Przedstawiono wyniki pomiarów odległości ramion dendrytów II rzędu lambda2 oraz długości średniej cięciwy i odległości osi dendrytów. Przeprowadzono statystyczną analizę wyników i wyznaczono zależności pomiędzy mierzonymi parametrami struktury.