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1
Content available Characteristics of rhizobacteria in potential hyperaccumulator vegetation and their resistance to gold mine tailing stress
Aminatun Tien, Rakhmawati Anna, Atun Sri, Idrus Arifudin, Simbolon Doly Risdo, Restele Laode
Journal of Water and Land Development
|
2024
|
no. 60
209--218
EN
The use of local bacteria is preferred in bioleaching as an environmental-friendly alternative technology in gold mining. In a preliminary study, rhizobacteria were isolated and cultured from three types of hyperaccumulator vegetation from the Ratatotok gold mine, Indonesia, namely Pteris vittata L., Syzygium aromaticum L., and Swietenia mahagoni Jacq. These rhizobacteria still need to be characterised and identified. This study is aimed to cover bacterial phenotypic characterisation, assessment of bacteria resistance to tailing, and identification of bacterial strains the exhibit the highest resistance to tailings. The assessment was carried out across a spectrum of tailing concentrations, selecting the three most robust strains for molecular identification. The process involved genotypic characterisation to determine the species name by analysing the 16S rRNA gene. The results reveal that the phenotypic characteristics of the bacteria isolates vary, but all of them are the indole acetic acid (IAA) hormone producers. The highest IAA producer is the isolate from the rhizosphere of S. aromaticum. Based on the genotypic characterisation test, three most resistant isolates to tailing stress are the following strains Pseudomonas aeruginosa (RTKP1) and Stenotrophomonas geniculata (RTKP2), both from the rhizosphere of P. vittata; as well as Bacillus cereus (RTKS) from the rhizosphere of S. aromaticum. These three strains need to be further tested for their bioleaching capability to recover gold from tailings. Additionally, this study recommends that gold recovery using biological agents can combine the role of hyperaccumulator plants in phytomining and rhizobacteria in bioleaching.
2
Content available remote Określenie wpływu konstrukcji zabudowy na nagrzewanie bezhalogenkowych przewodów elektrycznych
Perka Bogdan, Suproniuk Marek, Piwowarski Karol, Paziewski Piotr, Kaczmarek Witold
Przegląd Elektrotechniczny
|
2023
|
R. 99, nr 1
203--206
PL
Artykuł opisuje badania zjawisk wymiany ciepła pomiędzy otoczeniem, a przewodem elektrycznym podczas warunków termicznych przekraczających wartości dopuszczalne, dla powszechnie stosowanych przewodów elektrycznych niepalnych. Podjęto próbę wyznaczenia podstawowych parametrów cieplnofizycznych dla przewodu elektrycznego jako jednego układu fizycznego złożonego z żyły przewodzącej, izolacji żyły, izolacji zewnętrznej przewodu. Do budowy modelu przewodzenia ciepła przez przewód elektryczny, wykorzystane zostały dane pomiarowe uzyskane z zaprojektowanego eksperymentu dla trzech przypadków zabudowy przewodu: w otwartym korycie kablowym, w izolacji termicznej (PUR) oraz w zamkniętym kanale kablowym (light concrete). Do zamodelowania przepływu ciepła wykorzystano metodę analogii układów cieplnych i elektrycznych. Model matematyczny jest równaniem linii długiej (linia Kelwina – Thompsona) opisana parametrami rozproszonymi co stanowi własny wkład naukowy autorów w badanie zjawisk cieplnych w przewodach elektrycznych.
EN
The article describes the study of the heat exchange phenomena between the environment and the electric conductor during thermal conditions exceeding the permissible values for commonly used non-flammable electric cables. An attempt was made to determine the basic thermophysical parameters for an electric conductor as one physical system consisting of a conductor, conductor insulation, and outer insulation of the conductor. To build a model of heat conduction through an electric cable, the measurement data obtained from the designed experiment for three cases of cable installation were used: in an open cable tray, in thermal insulation (PUR) and in a closed cable channel (light concrete). The method of analogy of thermal and electrical systems was used to model the heat flow. The mathematical model is an equation of a long line (Kelvin - Thompson line) described with dispersed parameters, which is the authors' own scientific contribution to the study of thermal phenomena in electrical cables.
3
Content available Numerical investigation of length to beam ratio effects on ship resistance using ranse method
Le Tat Hien, Nguyen Duy Anh, Tran Ngoc Tu, Hoa Nguyen Thi Ngọc, Ngoc Vu Minh
Polish Maritime Research
|
2023
|
nr 1
13--24
EN
The paper discusses the length to beam (L/B) ratio effects on ship resistance at three different Froude numbers using unsteady RANSE simulation. First, the JBC ship model was used as an initial hull form for verification and validation of predicted ship resistance results with measured data, and then the influence of the L/B ratio on ship resistance was carried out. Ship hull forms with different L/B ratios were produced from the initial one by using the Lackenby method. The numerical results obtained show the L/B ratio’s effect on ship resistance. Increases of the L/B ratio led to gradual reduction of the total ship resistance and vice versa. Analysis of the changing of the resistance components indicates that the pressure resistance changes are considerably larger than the frictional one. Finally, the paper analyses the difference in the flow field around the hull of the ship with variation of the L/B ratio to fully understand the physical phenomenon in the change of ship resistance at different L/B parameters.
4
Content available Investigation of asymmetric twin-rudder load behaviour through free-running model tests
Efremov Dobrin, Milanov Evgeni
Polish Maritime Research
|
2023
|
nr 3
4--11
EN
During tight manoeuvres, twin-screw ships equipped with two rudders located in the propeller slip stream experience a fairly large imbalance in the hydrodynamic loads on the propeller and rudders. To investigate the phenomenon of rudder asymmetric load in some depth, manoeuvring experiments based on a free-running model were set up in which the kinematics of the model, the forces on the rudder and the stock moment were recorded. In parallel, with the aim of obtaining an exact estimation of free-stream characteristics of the rudder blade, corresponding wind tunnel experiments were also performed. Based on the results of this investigation, an analysis of the interaction effects within the hull-propeller-rudder system was performed and some conclusions were drawn.
5
Content available Determination of the reactance of rail vehicles wheelsets
Garczarek Adam, Woźniak Krystian, Olejniczak Tomasz, Waśkowicz Radosław, Stachowiak Dorota
Pojazdy Szynowe
|
2023
|
Nr 1-2
32--37
EN
The article presents issues related to the determination of resistance, impedance, and reactance of rail vehicles wheelsets in relation to applicable standards and regulations. The methodology of conducting this type of test is discussed, and a configured test stand is presented to measure the resistance and impedance of the wheelsets. The uncertainty budget for this type of testing is discussed. Exemplary measurement results are presented and analyzed.
6
Content available remote Zmiany w konstrukcji oraz elementach składowych stolarki okienno-drzwiowej wpływające na jej właściwości techniczno-użytkowe
Kopyłow Ołeksij
Materiały Budowlane
|
2023
|
nr 8
59--61
7
Elektronika w technice wysokich napięć : rezystory wysokonapięciowe
Perka Bogdan
Elektronika : konstrukcje, technologie, zastosowania
|
2023
|
Vol. 64, Nr 1
34--37
PL
Rezystory wysokonapięciowe to elementy, które wymagają specjalnych wymogów konstrukcyjnych, zwłaszcza w zakresie odporności napięciowej oraz charakteryzują się dużą mocą obciążenia. Poszukiwanie nowych rozwiązań konstrukcyjnych oraz materiałowych powoduje rozwój badań w tym zakresie, które są intensywnie wspomagane przez producentów elektronicznych wysokonapięciowych elementów pasywnych.
EN
High-voltage resistors are elements that require special design requirements, especially in terms of voltage resistance and are characterized by high load power. The search for new design and material solutions results in the development of research in this area, which is intensively supported by manufacturers of electronic high-voltage passive components.
8
Bezdotykowe pomiary temperatury podzespołów i elementów elektronicznych
Perka Bogdan
Elektronika : konstrukcje, technologie, zastosowania
|
2023
|
Vol. 64, Nr 2
29--31
PL
Pomiary temperatury otoczenia elektronicznych urządzeń i podzespołów pozwalają na sprawdzenie warunków pracy tychże urządzeń oraz podjęcie odpowiednich działań jeżeli warunki te odbiegają od nominalnych. Do wyboru mamy kilka metod pomiarowych. W tym artykule zostały opisane metody bezdotykowe.
EN
Measuring the ambient temperature of electronic devices and components allows the operating conditions of these devices to be checked and appropriate action taken if these conditions deviate from the nominal. There are several measurement methods to choose from. In this article, non-contact methods are described.
9
Ocena stanu izolacji instalacji elektrycznej
Łozowski Aleksander
Elektro Info
|
2023
|
nr 5
36--38
PL
W artykule podano sposób oceny stanu izolacji instalacji elektrycznej na podstawie pomiaru prądu upływu, pobieranej mocy czynnej przez odbiorniki oraz jej rozległości (długości). Pozwala to zastosować zalecenie normowe, aby w trakcie przeglądów okresowych nie wykonywać demontażu instalacji. Tak wykonane badanie kontrolne instalacji zmniejsza koszty przeglądu oraz pozwala ocenić jej stan w trakcie pracy, wraz z przyłączonymi urządzeniami odbiorczymi.
10
Content available Energy Infiltration Effect and Energy Body : a Unique Criterion for Building Thermal Insulation
Bieranowski Piotr
Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa
|
2022
|
Vol. 13, Nr 1 (47)
79--92
EN
This publication is provided with the author’s suggestions regarding modification of the basic criterion – heat transfer coefficient. According to the author, the basic criterion of building thermal protection should be extended in such a manner that it will be simple and easy to evaluate a building’s capacity to recover thermal energy accumulated in the wall structure.
PL
W publikacji zamieszczono autorskie propozycje modyfikacji podstawowego kryterium, jakim jest współczynnik przenikania ciepła. Zadaniem autora powinno się rozbudować podstawowe kryterium ochrony cieplnej budynków, tak, aby w podstawowy i łatwy sposób można było ocenić zdolność obudowy budynku do odzysku energii cieplnej – zakumulowanej w konstrukcji ściany.
11
Content available CFD optimisation of the longitudinal volume distribution of a ship’s hull by constrained transformation of the sectional area curve
Kraskowski Marek
Polish Maritime Research
|
2022
|
nr 3
11--20
EN
The paper presents a proposal for a formalised approach to hull shape optimisation with respect to total resistance, by fine-tuning longitudinal volume distribution. An algorithm for automated modification of the hull is presented, allowing for varying the sectional area distribution with a negligible influence on the resulting displacement. Computational fluid dynamics (CFD) solver STAR-CCM+ and computer computer-aided design (CAD) software NX were used to search the optimal volume distribution of selected parent shapes, with respect to total resistance. The bow part and the aft part were optimised separately. The resulting resistances of the selected optimal shapes were then verified by means of scale model tests, realised in the towing tank at the Maritime Advanced Research Centre (CTO) S.A. A noticeable gain in total resistance was achieved and confirmed by experimental tests. The proposed approach seems to be a promising method for relatively quick parametric optimisation of the designed hull shapes; it is also applicable for generic CFD optimisation studies.
12
Content available remote Resistance of geopolymers to chemical aggression. Literature study
Słomka-Słupik Barbara, Wiśniewska Paulina
Ochrona przed Korozją
|
2022
|
nr 12
378--392
EN
Geopolymers, or mineral polymers, are binders formed as a result of the alkaline activation of anthropogenic or natural minerals. Recently, they have attracted the attention of many scientists who justify the need to reduce carbon dioxide emissions during cement production by using other materials. The paper lists the materials used in the production of geopolymer binders, describes the geopolymerization process, and characterizes the method of corrosion of cement binders in relation to the results of research carried out on geopolymer binders. The main focus was on the resistance of geopolymers to chemical factors such as acids, sulphates, carbon dioxide and ammonium salts. Chloride penetration was indicated in the context of water absorption depending on the geopolymeric matrix microstructure. The results of the research on the reaction of alkali-silicate geopolymers are also described. Research presented mainly by foreign research units confirmed that geopolymer binders are characterized by much better properties than cement binders.
PL
Geopolimery, czyli mineralne polimery, to spoiwa powstające wskutek alkalicznej aktywacji minerałów antropogenicznych lub naturalnych. W ostatnim czasie skupiły uwagę wielu naukowców uzasadniających potrzebę redukcji emisji dwutlenku węgla wydzielającego się podczas wytwarzania cementu przez użycie innych materiałów. W pracy wyszczególniono materiały stosowane w produkcji spoiw geopolimerowych, opisano proces geopolimeryzacji i scharakteryzowano budowę geopolimerów. Porównano również sposób destrukcji materiałów cementowych z geopolimerowymi. Skupiono się głównie na odporności geopolimerów na działanie czynników chemicznych: kwasów, siarczanów, dwutlenku węgla, soli amonowych. Wskazano na wnikanie chlorków jako przykład transportu zależnego od mikrostruktury geopolimerowej matrycy, od możliwości wnikania wody. Opisano również wyniki badań reakcji alkalia-krzemionka zachodzącej w betonach. W badaniach, prezentowanych głównie przez jednostki zagraniczne, potwierdzono, że spoiwa geopolimerowe charakteryzują się dużo lepszymi właściwościami aniżeli spoiwa cementowe.
13
Content available The Conditions of Human Behaviour in the Process of Changes
Ścibiorek Zbigniew
Logistics and Transport
|
2022
|
Vol. 53-54, No. 1-2
37--59
EN
The article deals with various issues related to changes, mainly resistance to them. Basic premises of transformations and doubts that may appear among the organization’s personnel have been discussed. Not only the issues concerning the resistance itself have been included, but also the reasons that determine its intensity and several methods that may be used in practice have been mentioned as well. The study is the result of materials analysis on the aspects of changes determinants and resistance to transformations that are permanently integrated into the functioning of each organization, also strongly hierarchical, which is the army.
14
Content available Computational prediction of the resistance of the the floatplane at various trim angles
Sulisetyono Aries, Fadhlurrohman Ihsan, Ali Baharudin, Zubaydi Achmad
Journal of Theoretical and Applied Mechanics
|
2022
|
Vol. 60 nr 2
267--278
EN
The prediction of the total resistance occurred during operation of a floatplane on the water surface is an important aspect in developing the floater as well as the engine power required. Theoretically, the trim angle of the floater may affect the total resistance. This paper intends to find the optimal trim angle for the take-off operation using the computational fluid dynamics (CFD) software. The floater set up under a fixed trim angle includes 2◦, 5◦ and 10◦ taken in simulation at five different speeds between 9.21 m/s and 15.87 m/s. In one case of 2◦ trim angle, the floater model test has been carried out in a tow tank laboratory to validate the accuracy of the numerical result. Comparison of both results has a good fit with an average error of 2.27%. In the final simulation results, the optimum trim angle is 5◦, which produces the total resistance less than 2◦ and 10◦ of the trim angle with average differences of 9.21% and 50.46% for all speeds, respectively.
15
Content available Study of Drought Effects on Three Medicinal and Aromatic Plants Using Field Spectroscopy
El Azizi Sarah, Amharref Mina, Bernoussi Abdes-Samed
Journal of Ecological Engineering
|
2022
|
Vol. 23, nr 12
155--162
EN
Water deficit is one of the major environmental issues affecting biodiversity. Drought-related works are conducted to explore the mechanisms involved in drought vulnerability or resistance and to adopt the most advantageous tool to monitor these changes. Field spectroscopy, an accessory tool of remote sensing, evaluates the reflectance to collect continuous spectrum from materials. In the conducted study, the potential of using UV-Near infrared (NIR) spectroscopy as a non-destructive and reliable approach in monitoring of drought effects on three Medicinal and Aromatic Plants species (MAPs): Lavandula stoechas, Cistus laurifolius and Pistacia lentiscus from Northern Morocco during dry (July 2021) and wet (March 2022) period was addressed. It was found that Lavandula stoechas species is more impacted by water deficit than Cistus laurifolius and Pistacia lentiscus. Indeed, this species has a lower reflectance in Visible and NIR regions of the spectrum after a period of drought and therefore a higher vulnerability to water deficit than the other two species.
16
Content available Nośność mimośrodowo ściskanych słupów betonowych ze zbrojeniem niemetalicznym
Korentz Jacek
Builder
|
2022
|
R.26, nr 4
62--64
PL
W konstrukcjach z betonu coraz częściej mają zastosowanie pręty kompozytowe FRP, które są wykonywane z różnych materiałów. Właściwości mechaniczne dostępnych na rynku prętów kompozytowych są bardzo zróżnicowane. Pręty kompozytowe różnią się od stalowych prętów zbrojeniowych: charakteryzują się bardzo wysoką wytrzymałością i niskim modułem sprężystości. Pręty te zachowują się sprężyście w całym zakresie obciążeń, a ich zniszczenie następuje w sposób nagły. Z tego względu zachowanie się słupów zbrojonych prętami kompozytowymi odbiega od znanego zachowania się słupów ze zbrojeniem stalowym: nośność tych słupów jest zróżnicowana. W artykule przeanalizowano wpływ rodzaju zastosowanego zbrojenia podłużnego w słupach krępych na interakcję sił granicznych momentu zginającego i siły podłużnej. Słupy ze zbrojeniem niemetalicznym w stosunku do słupów ze zbrojeniem stalowym charakteryzują się większą lub mniejszą nośnością w zależności od rodzaju kompozytu oraz wielkości mimośrodu siły podłużnej.
EN
FRP composite bars, which are made from various materials, are increasingly used in concrete structures. The mechanical properties of commercially available composite bars vary greatly. Composite bars are different from steel reinforcing bars; they have very high strength and a low modulus of elasticity. These bars behave elastically over the entire load range and their failure is sudden. Therefore, the behavior of columns reinforced with composite bars may differ from the known behavior of columns with steel reinforcement; the load capacity of the columns varies. This paper investigates the influence of the type of longitudinal reinforcement used in brittle columns on the interaction of bending moment and longitudinal force limit forces. Columns with non-metallic reinforcement compared to columns with steel reinforcement have a higher or lower load capacity depending on the type of composite and the eccentricity of the longitudinal force.
17
Content available Research on sand resistance performance of comprehensive protection facilities for desert hinterland highways under strong wind environment
Yin Wenhua, Wang Xu, Wu Yongxiang, Wang Fang
Archives of Civil Engineering
|
2022
|
Vol. 68, nr 4
683--698
EN
Based on the test and observation of the desert hinterland wind field, combined with the numerical simulation of Fluent wind-sand two-phase flow, the sand resistance performances of comprehensive protection in the desert hinterland under strong wind environment are researched. The transient wind speed and wind direction around the comprehensive protection facility are measured by two 3D ultrasonic anemometers on the highway in the desert hinterland, and the initial wind speed of the sand flow is provided for the numerical simulation boundary. The sedimentary sand particles around the comprehensive protection facility are collected for particle size analysis, and the particle size distributions of sedimentary sand particles at different locations are obtained. Numerical models of high vertical sand barriers, grass checkered sand barriers and roadbeds are established by Fluent, the wind-sand flow structures around the comprehensive protection facilities and desert hinterland highway under the strong wind environment are obtained, and the influence laws of the comprehensive protection facilities on the movement of wind-sand flow and sand deposition characteristics are obtained. The study found that the comprehensive protection facilities disturbed the wind and sand flow, and there are significant airflow partitions around the comprehensive protection facilities. The wind speed decreases rapidly after the wind-sand flows through the high vertical sand barrier; the wind-sand flow rises at the end of the high vertical sand barrier. When the wind-sand flow moves around the grass checkered sand barrier, the wind speed has dropped to the range of 0-3 m/s, and the wind speed near the ground by the grass checkered sand barrier is further reduced. Due to the existence of the concave surface of the grass grid, there are small vortices inside the grass grid sand barrier. Large sand particles are mainly deposited on the windward side and inside of high vertical sand barriers. The grass checkered sand barrier forms a stable concave surface to generate backflow, which can ensure that the sand surface does not sand itself in a strong wind environment, and can also make a small amount of sand carried in the airflow accumulate around the groove of the grass checkered sand barrier. The numerical simulation results are consistent with the measured results, and the comprehensive protection measures have achieved good sand control effects.
18
Content available remote Rozpraszanie energii elektrycznej w przewodach elektrycznych pod wpływem temperatur pożarowych
Perka Bogdan
Przegląd Elektrotechniczny
|
2021
|
R. 97, nr 6
103--106
PL
W artykule przedstawione zostały mechanizmy rozpraszania nośników ładunku elektrycznego w żyłach przewodzących przewodów elektrycznych poddanych termicznemu oddziaływaniu temperatur pożarowych. Określona została wielkość wpływu mechanizmów rozpraszających na pogorszenie warunków przewodności elektrycznej i podane zostały przybliżone wyniki obliczeń wzrostu rezystancji żył przewodzących.
EN
The article presents the mechanisms of dissipation of electric charge carriers in the conductors of electric cables subjected to the thermal effect of fire temperatures. The influence of dissipation mechanisms on the deterioration of electrical conductivity conditions was determined and approximate results of calculations of the increase in resistance of the conductive wires.
19
Content available Network Water Quality at a Hospital Center in Morocco: Bacteriological Survey and Relationship with Human Health
Flouchi Rachid, Elmniai Abderrahim, Abbou Mohamed Ben, Touzani Ibrahim, Fikri-Benbrahim Kawtar
Journal of Ecological Engineering
|
2021
|
Vol. 22, nr 9
185--191
EN
Water is mandatory for the functioning of hospitals. Its consumption varies from one service to another, and its use can reduce the service quality on one hand and presents a major risk of nosocomial infection on the other hand. The health risks related to the use of water in hospitals are mostly microbiological, but sometimes they can be chemical. For this reason, the conducted work aimed to evaluate, for the first time, the quality and bacteriological efficiency of the network water of the provincial hospital center IBN BAJA in Taza, Northeast Morocco. During one year, 72 samples were analyzed in six surgery departments, one sample per month for each ward at a rate of six samples per month and per department. The results obtained showed that the water quality of the hospital network was in conformity with the requirements of the Moroccan standards. Nonetheless, some bacterial strains such as Aeromonas salmonicida spp salmonicida, Enterococcus spp., Pseudomonas luteola, Sphingomonas paucimobilis, Pseudomonas stutzeri, Stenotrophonomas maltophilia, Burkholderia cepacia and Micrococcus luteus, which constitute a major risk to human health, were found. Moreover, after sensitivity evaluation to the twenty-seven antibiotics, some strains have been shown to be multi-resistant, which can present a major risk of nosocomial infections in the studied hospital for human beings.
20
Content available Construction of reservoirs using polymer-mineral materials N1 and PMM
Tokmajan Vache, Vartanyan Artur, Mikayelyan Nver
Budownictwo o Zoptymalizowanym Potencjale Energetycznym
|
2021
|
Vol. 10 Nr 2
31--38
EN
This paper presents technological innovations based on new hydraulic insulating materials, the use of which in reservoir construction will essentially reduce construction costs by up to half. New polymer-mineral based waterproofing materials N1 and PMM can be used to construct inexpensive reservoirs. In particular, a thoroughly mixed mixture of soil taken from the bottom of a reservoir or other substrate with PMM material at a ratio of 30 grams PMM to one kg of the substrate, laid on the bottom of the reservoir with a thickness of at least 10 cm, and tamped down to a layer of 7 cm or less, will withstand at least 2.5-3 atm pressure of water column. A similar result can be obtained if a 5 cm thick layer of N1 material is laid on the reservoir bottom, together with pebbles to reduce the cost of the proposed solution.
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