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Zaštita Materijala 1. 2022

Dorothy Rajendran1*, Thankappan Sasilatha1, Suvakeen Amala Doss Hebciba Mary2, Susai Santhammal Rajendran2,3, Caslav Lacnjevac4, Gurmeet Singh5

1AMET University, Department of EEE, Chennai, India, 2Department of Chemistry, St. Antony’s College of Arts and Sciences for Women Thamaraipady, Tamil Nadu, India,3Pondicherry Uniersity, Puducherry, India  4University of Belgrade, Faculty of Agriculture, Belgrade, Serbia, 5 Pondicherry University,  Puducherry, India.

Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585 https://doi.org/10.5937/zasmat2201015R

Zastita Materijala 63 (1)
15 – 14  (2022)

 

Deep learning based underwater metal object detection using input image data and corrosion protection of mild steel used in underwater study – A case study

Part A – Deep learning based underwater metal object detection using input image data

Abstract

Due to the importance of underwater exploration in the development and utilization of deep-sea resources, underwater autonomous operation is more and more important to avoid the dangerous high-pressure deep-sea environment. For underwater autonomous operation, the intelligent computer vision is the most important technology. In an underwater environment, weak illumination and low-quality image enhancement, as a pre-processing procedure, is necessary for underwater vision. In this paper, introduced the Deep learning based Underwater Metal object detection using input Image data by using several step to improve the model performance. In this experimentation we are using TURBID dataset 100 images to validate the performance. And also we compare the performance result by given the input images in different validation level. In first input image is initially preprocessed and that images is given to the KFCM-Segmentation. The segmented images are given to the DWT Extraction to extract the features from those images. And finally the Convolution Neural Network (CNN) is used to classify the images to detect the objects. Also this proposed model attained the classification accuracy of 98.83%. This method is much suitable for detect the objects in underwater robotically. Metallic parts of machines of ships or aero planes may submerge in sea water. They may undergo corrosion when they come in contact with sea water which contains 3.5% sodium chloride. This is most commonly responsible for the corrosive nature of the sea water. The robots made of materials such as mild steel may also undergo corrosion when they come in contact with sea water, while is search. If a paint coating is given, it will control the corrosion of these proposed materials. Hence this work is undertaken. Mild steel is coated with Asian guard red paint. Corrosion resistance of mild in3.5% sodium chloride solution is measured before coating and after coating by electrochemical studies such as such as polarization study and AC impedance spectra . The corrosion inhibition efficiency offered by red paint to mild steel in 3.5% sodium chloride is 99.98%.

Keywords: input Image data, Convolutional Neural Network (CNN), Fuzzy c-means clustering and TURBID dataset polarization study, AC impedance spectra, sea water.

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Detektovanje podvodnih metalnih objekata pomoću veštačke inteligencije i zaštita od korozije predmeta od mekog čelika korišćenih u podvodnoj studiji – Studija slučaja

Deo A – detektovanje podvodnih metalnih objekata pomoću veštačke inteligencije

Zbog važnosti podvodnog istraživanja u razvoju i korištenju dubokomorskih resursa, podvodni autonomni rad je sve važniji kako bi se izbeglo opasno dubokomorsko okruženje pod visokim pritiskom. Za podvodni autonomni rad, inteligentni računarski vid je najvažnija tehnologija. U podvodnom okruženju, slabo osvetljenje i nekvalitetno poboljšanje slike, kao postupak prethodne obrade, neophodni su za podvodni vid. U ovom radu predstavljeno je otkrivanje podvodnih metalnih objekata zasnovanog na veštačkoj inteligenciji pomoću ulaznih podataka o slici koristeći nekoliko koraka za poboljšanje performansi modela. U ovom eksperimentu koristi se TURBID skup podataka od 100 slika za proveru performansi. Takođe, upoređuje se rezultat performansi prema datim ulaznim slikama na različitim nivoima validacije. U prvom slučaju, ulazna slika se prethodno obrađuje i te slike se daju u KFCM-segmentaciji. Segmentirane slike se daju DVT ekstrakciji da izdvoje karakteristike iz tih slika. I na kraju, Convolution Neural Netvork (CNN) se koristi za klasifikaciju slika radi otkrivanja objekata. Takođe, ovaj predloženi model dostigao je tačnost klasifikacije od 98,83%. Ova metoda je veoma pogodna za robotsko otkrivanje objekata u morskim dubinama. Metalni delovi mašina brodova ili aviona mogu potonuti u morsku vodu. Mogu doći do korozije u kontaktu sa morskom vodom koja sadrži 3,5% natrijum hlorida. Ovo je najčešće odgovorno za korozivnu prirodu morske vode. Roboti napravljeni od materijala kao što je meki čelik, takođe, mogu pretrpeti koroziju kada dođu u kontakt sa morskom vodom, dok je u toku pretraga. Ako se nanese premaz boje, on će kontrolisati koroziju ovih predloženih materijala. Zbog toga se ovaj posao preduzima. Meki čelik premazan je azijskom zaštitnom crvenom bojom. Otpornost na koroziju blagog 3,5% rastvora natrijum hlorida meri se pre nanošenja i nakon nanošenja elektrohemijskim studijama, kao što su polarizacione studije i spektri impedanse naizmenične struje. Efikasnost sprečavanja korozije koju crvena boja nudi mekom čeliku u 3,5% natrijum hloridu je 99,98%.

Ključne reči: ulazni podaci o slici, Konvoluciona neuronska mreža (CNN), klasterisanje sa srednjim vrednostima, Studija polarizacije TURBID skupa podataka, Spektar impedanse naizmenične struje, morska voda.

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Dorothy Rajendran1*, Thankappan Sasilatha1, Suvakeen Amala Doss Hebciba Mary2, Susai Santhammal Rajendran2,3, Caslav Lacnjevac4, Gurmeet Singh5

1AMET University, Department of EEE, Chennai, India, 2Department of Chemistry, St. Antony’s College of Arts and Sciences for Women Thamaraipady, Tamil Nadu, India,3Pondicherry Uniersity, Puducherry, India,  4University of Belgrade, Faculty of Agriculture, Belgrade, Serbia, 5 Pondicherry University, Puducherry, India.

Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585 https://doi.org/10.5937/zasmat2201015R

Zastita Materijala 63 (1)
15 – 22  (2022)

 

Deep learning based underwater metal object detection using input image data and corrosion protection of mild steel used in underwater study – A case study

Part B – Corrosion protection of mild steel used in underwater study

Abstract

Buried metal objects in sea water may undergo corrosion because of the corrosive ions such as chloride ions present in seawater. However a paint coating may control the corrosion of the metal objects such as robots. Corrosion resistance of mild steel in 3.5 % sodium chloride solution before and after coating with Asian guard red paint has been evaluated by polarization study and AC impedance spectra. In presence of Asian guard red paint, the linear polarization resistance increases, corrosion current decreases, charge transfer resistance increases, double layer capacitance decreases and impedance value increases. That is corrosion resistance of mild steel objects in 3.5 % sodium chloride solution increases after coating with Asian guard red paint.

Keywords: mild steel objects, robots, coating, Asian guard red paint, polarization study, AC impedance spectra, sea water, 3.5% sodium chloride.

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Detektovanje podvodnih metalnih objekata pomoću veštačke inteligencije i zaštita od korozije predmeta od mekog čelika korišćenih u podvodnoj studiji – Studija slučaja

Deo B – Zaštita od korozije predmeta od mekog čelika korišćenih u podvodnoj studiji

Ukopani metalni predmeti u morskoj vodi mogu proći koroziju zbog korozivnih jona, poput hloridnih jona prisutnih u morskoj vodi. Međutim, boja može kontrolisati koroziju metalnih predmeta kao što su roboti. Otpornost na koroziju mekog čelika u 3,5 % rastvoru natrijum hlorida pre i posle premazivanja azijskom zaštitnom crvenom bojom procenjena je polarizacionom studijom i spektrom impedanse naizmenične struje. U prisustvu azijske zaštitne crvene boje, otpor linearne polarizacije se povećava, struja korozije se smanjuje, otpor prenošenja naboja raste, kapacitet dvostrukog sloja se smanjuje, a vrednost impedanse raste. Tako je otpornost na koroziju predmeta od mekog čelika u 3,5 % rastvoru natrijum hlorida nakon premazivanja azijskom zaštitnom crvenom bojom poboljšana.

Ključne reči: predmeti od meki čelik, roboti, premazi, azijska zaštitna crvena boja, polarizaciona studija, spektri impedanse naizmenične struje, morska voda.

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Dorothy Rajendran1, Thankappan Sasilatha1, Susai Santhammal Rajendran2,5*, Abdulhameed Al-Hashem3, Caslav Lacnjevac4, Gurmeet Singh5

1AMET University, Department of EEE, East Coast Road, Chennai, India, 2Department of Chemistry, St. Antony’s College of Arts and Sciences for Women Thamaraipady, Dindigul–624005,Tamil Nadu, India, 3Petroleum Research Centre, Kuwait Institute for Scientific Research , Kuwait, 4University of Belgrade, Faculty of Agriculture, Belgrade, Serbia, 5Pondicherry University, Puducherry, India

Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
https://doi.org/10.5937/zasmat2201023R

Zastita Materijala 63 (1)
23 – 36  (2022)

 

Inhibition of corrosion of mild steel hull plates immersed in natural sea water by sandalwood oil extract of some natural products

Abstract

The hull plates of the ship made of mild steel (MS) are always in contact with sea water are always in contact with aggressive ions such as chloride ions present in sea water.The corrosion resistance of the hull plates of the ship made of mild steel has been investigated by polarization study. Sandalwood oil extract containing 5 g each of Cardamom (disambiguation), Clove (disambiguation), Nutmeg, India Sambrani (loban), Chrysopogon zizanioides, commonly known as vetiver and Camphor was used as corrosion inhibitor along with Trisodium citrate (TSC), sodium dihydrogen phosphate (SDP) and Zn2+. The corrosion resistance was measured in the absence and presence of various inhibitor systems: Trisodium citrate (TSC) 100 ppm+ Zn2+ 50ppm system, sodium dihydrogen phosphate (SDP) 100 ppm+ Zn2+ 50ppm system, Oil coated (3days) MS, Oil coated (3days) MS +TSC 100 ppm+ Zn2+ 50 ppm system and Oil coated (3days) MS +SDP100 ppm+ Zn2+ 50 ppm system were used. It is observed that when mild steel is immersed in SW+TSC 100 ppm+ Zn2+ 50ppm system , the corrosion resistance of MS increases. When mild steel is immersed in SW+ SDP 100 ppm+ Zn2+ 50ppm system , the corrosion resistance of MS increases. When mild steel is immersed in Oil coated (3days) MS in Sea water system , the corrosion resistance of MS increases. When mild steel is immersed in Oil coated (3days) MS in SW+TSC 100 ppm+ Zn2+ 50ppm system , the corrosion resistance of MS increases. When mild steel is immersed in Oil coated (3 days) MS in SW+ SDP 100 ppm+ Zn2+ 50ppm system , the corrosion resistance of MS increases. This is revealed by the fact that there is increase in LPR value and decrease in corrosion current value. The corrosion potential is shifted to anodic side. This indicates that in this inhibitor system, the anodic reaction of metal dissolution is controlled predominantly. This implies that these inhibitor systems may be coated on mild steel surface used as hull plates to prevent corrosion of mild steel in sea water.

Keywords: corrosion inhibition, hull plates, mild steel, sea water, green inhibitors, electrochemical study.

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Sprečavanje korozije ploča od mekog čelika potopljenih u morsku vodu ekstraktom ulja nekih prirodnih proizvoda

Izvod

Ploče trupa broda od mekog čelika (MČ) su uvek u kontaktu sa morskom vodom i uvek su u kontaktu sa agresivnim jonima, kao što su hloridni joni prisutni u morskoj vodi. Otpornost na koroziju ploča trupa broda od mekog čelika je istražen proučavanjem polarizacije. Ekstrakt ulja sandalovine, koji sadrži po 5 g kardamoma, karanfilića, muskatnog oraščića, Indija Sambrani (loban), Chrysopogon zizanioides, poznatijeg kao vetiver i kamfor, korišćen je kao inhibitor korozije zajedno sa trinatrijum citratom, natrijum dihidrogenom fosfat i Zn2+. Otpornost na koroziju je merena u odsustvu i prisustvu različitih inhibitornih sistema: Trinatrijum citrat (TSC) 100 ppm+ Zn2+ 50 ppm sistem, natrijum dihidrogen fosfat (SDP) 100 ppm+ Zn2+ 50 ppm sistem, obložen uljem (3 dana) MČ, uljem premazan (3 dana) MČ +TSC 100 ppm+ sistem obložen ZN2+ 5 ppm+ sistem MS +SDP100 ppm+ Zn2+ 50 ppm. Primećeno je da kada je meki čelik uronjen u sistem SV+TSC 100 ppm + Zn2+ 50ppm, otpornost MČ na koroziju se povećava. Kada je meki čelik uronjen u sistem SV+ SDP 100 ppm + Zn2+ 50 ppm, otpornost MČ na koroziju se povećava. Kada se meki čelik uroni u MS obložen uljem (3 dana) u sistem morske vode, otpornost MČ na koroziju se povećava. Kada se meki čelik uroni u MS obložen uljem (3 dana) u sistem SV+TSC 100 ppm + Zn2+ 50ppm, otpornost MČ na koroziju se povećava. Kada se meki čelik uroni u MS obložen uljem (3 dana) u sistem SV+ SDP 100 ppm + Zn2+ 50 ppm, otpornost MČ na koroziju se povećava. Ovo se objašnjava činjenicom da dolazi do povećanja vrednosti LPR i smanjenja vrednosti struje korozije. Potencijal korozije se pomera na anodnu stranu. Ovo ukazuje da se u ovom sistemu inhibitora pretežno kontroliše anodna reakcija rastvaranja metala. Ovo implicira da se ovi sistemi inhibitora mogu obložiti na površinu od mekog čelika koji se koristi kao ploče trupa da bi se sprečila korozija mekog čelika u morskoj vodi.

Ključne reči: inhibicija korozije, ploče trupa, meki čelik, morska voda, zeleni inhibitori, elektrohemijska studija.

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Aurel Nuro*, Bledar Murtaj, Elda Marku

Tirana University, Department of Chemistry, Faculty of Natural Sciences, Tirana, Albania

Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
https://doi.org/10.5937/zasmat2201037N

Zastita Materijala 63 (1)
37 – 49  (2022)

 

Some of the characteristic substances in the Devola River, Albania

Abstract

This preliminary study presents first data on organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) concentrations in water and sediment samples of Devolli River. It is located in Southeast Albania, in Korca field, which is the second agricultural area in Albania. Sampling stations water of Devolli River were selected in eight different stations, starting from its stream (Gramozi Mountain) to the end of Korca field, near Banja hydropower (Gramshi region). Sampling of water and sediments were done in the same stations, in December 2018. Pesticides were used in the past in this area for many years mainly for agricultural purposes. Also, basin of Devolli River is affected from industrial activity and urban pollution, too. Water irrigation and rainfall contribute on their transport from soil to underground and surface waters. Organochlorine pesticides and PCB are very stable compounds that can be found in the environment for many years after their application. Liquid-liquid extraction was used for isolation of OCPs and PCBs in water samples while ultrasonic extraction was used for their extraction in sediment samples. The simultaneous analysis of organochlorine pollutants in water samples was performed by gas chromatography technique using electron capture detector (GC/ECD). Rtx-5 capillary column (30 m x 0.33 mm x 0.25 um) was used for separation of 17 organochlorine pesticides according EPA 8081A and 7 PCB markers. Relatively high concentrations of organochlorine pesticides were detected in water and sediment samples of Devolli River compare with other rivers of Albania. Their presence can be due to their previous use in Korca field. Volatile PCBs were found in higher concentration in water samples because of atmospheric deposition. Levels of some individual pesticides in surface water samples of Devolli River were found to be higher than permitted levels according to Albania and EU norms. Responsible authorities should be done continues monitoring in water samples of this river.

Keywords: Devolli River; organochlorine pesticides; PCB markers; water analyze; sediment analyze; GC/ECD

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Neke od karakterističnih supstanca u reci Devoli, Albanija

Izvod

Ova preliminarna studija daje prve podatke o koncentracijama organohlornih pesticida (OCP) i polihlorisanih bifenila (PCB) u uzorcima vode i sedimenata reke Devolli. Nalazi se u jugoistočnoj Albaniji, u polju Korča, koje je druga poljoprivredna oblast u Albaniji. Stanice za uzorkovanje vode reke Devoli odabrane su u osam različitih stanica, počevši od njenog toka (planina Gramozi) do kraja polja Korča, u blizini hidroelektrane Banja (region Gramši). Uzorkovanje vode i nanosa urađeno je na istim stanicama, u decembru 2018. Pesticidi su se u prošlosti na ovom području godinama koristili uglavnom u poljoprivredne svrhe. Takođe, sliv reke Devoli je, takođe, pogođen industrijskim aktivnostima i urbanim zagađenjem. Navodnjavanje vodom i padavine doprinose njihovom transportu iz tla u podzemne i površinske vode. Organohlorni pesticidi i PCB su veoma stabilna jedinjenja koja se mogu naći u životnoj sredini mnogo godina nakon njihove primene.

Ekstrakcija tečnost-tečnost je korišćena za izolovanje OCP i PCB u uzorcima vode, dok je ultrazvučna ekstrakcija korišćena za njihovu ekstrakciju u uzorcima sedimenta. Istovremena analiza organohlornih zagađivača u uzorcima vode obavljena je tehnikom gasne hromatografije korišćenjem detektora za hvatanje elektrona (GC/ECD). Rtk-5 kapilarna kolona (30 m k 0,33 mm k 0,25 um) korišćena je za odvajanje 17 organohlornih pesticida prema EPA 8081A i 7 PCB markera.

Relativno visoke koncentracije organohlornih pesticida su otkrivene u uzorcima vode i sedimenta reke Devoli u poređenju sa drugim rekama Albanije. Njihovo prisustvo može biti posledica njihove prethodne upotrebe u polju Korča. Isparljivi PCB su pronađeni u većoj koncentraciji u uzorcima vode zbog atmosferskog taloženja. Utvrđeno je da su nivoi pojedinih pesticida u uzorcima površinske vode reke Devoli veći od dozvoljenih prema normama Albanije i EU. Nadležni organi treba da vrše kontinuirani monitoring u uzorcima vode ove reke.

Ključne reči: reka Devolli; Organohlorni pesticidi; PCB markeri; Analiza vode; Analiza sedimenta; GC/ECD

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Vladimir D. Jović*

University of Belgrade, Institute for Multidisciplinary Research, Belgrade, Serbia

Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
https://doi.org/10.5937/zasmat2201050J

Zastita Materijala 63 (1)
50 – 57  (2022)

 

Calculation of a pure double layer capacitance from a constant phase element in the impedance measurements

Abstract

Considering literature of electrochemical impedance spectroscopy (EIS) it was discovered that for calculation of the value of double layer capacitance (Cdl) from the constant phase element (CPE) two equations, with or without solution resistance (Rs) could be used. After calculation of Cdl for defined values of CPE constant Ydl, CPE exponent a, Rs and charge transfer resistance (Rct), it was confirmed in this work that different results for Cdl were obtained by including Rs in the calculation of Cdl. It was also stated that “it is quite difficult to understand how both parameters (Rct and Rs) could be expressed by the same time constant, i.e. the same parameter a.” By investigating the hydrogen evolution reaction (HER) at Ni mesh 40 electrode in the solution of 1 M KOH at 25 oC using EIS measurements, it was shown that different Cdl vs. E plots were obtained using these two equations for Cdl calculation. A simple solution to avoid this problem with detailed explanation, the use of equation without Rs, has been suggested in this work.

Keywords: electrochemical impedance spectroscopy, double layer capacitance, constant phase element, hydrogen evolution reaction

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Izračunavanje prave vrednosti kapaciteta dvojnog sloja iz konstantnog faznog elementa u impedansnim merenjima

Izvod

Razmatrajući literature o elektrohemijskoj impedansnoj spektroskopiji (EIS) ustanovljeno je da za izračunavanje vrednosti kapaciteta dvojnog sloja (Cdl) iz konstantnog faznog elementa (CPE) postoje dve jednačine, jedna u kojoj figuriše otpor elektrolita (Rs) i druga u kojoj ovaj parametar ne figuriše. Izračunavanjem vrednosti Cdl za definisane parametre (Ydl, a, Rs, Rct), u ovom radu je pokazano da se dobijaju drugačiji rezultati za Cdl primenom ovih jednačina. Takođe je konstatovano da je neprihvatljivo da oba parametra (Rct i Rs) na isti način zavise od vremenske konstante, odn. od parametra a. Ispitivanjem reakcije izdvajanja vodonika na Ni mrežici u rastvoru 1 M KOH na 25 oC korišćenjem impedansnih merenja, pokazano je da su zavisnosti Cdl vs. E, dobijene korišćenjem pomenutih jednačina, različite. Da bi se izbegao ovaj problem predloženo je da se koristi jednačina u kojoj ne figuriše otpor elektrolita (Rs), jer uvodjenje Rs nema korektan fizički smisao.

Ključne reči: elektrohemijska impedansna spektroskopija, kapacitet dvojnog sloja, konstantni fazni element, rekacija izdvajanja vodonika

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Nebojša Đ. Pantelić1, Jana Štrbački2, Ivana Maloparac1, Nikola Tomašević1, Biljana P. Dojčinović3, Aleksandar Ž. Kostić1

1University of Belgrade, Faculty of Agriculture, Department of Chemistry and Biochemistry, Belgrade, Serbia, 2University of Belgrade, Faculty of Mining and Geology, Department of Hidrogeology, Belgrade, Serbia, 3University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Belgrade, Serbia

Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
https://doi.org/10.5937/zasmat2201058P

Zastita Materijala 63 (1)
58 – 67  (2022)

 

Multi-elemental analysis of real water samples from the Požega area, Serbia

Abstract

The aim of this study was to examine the quality of real samples of drinking water, collected from the territory of the city of Požega and the surrounding rural areas. An analytical technique of inductively coupled plasma with optical emission spectrometry (ICP-OES) was used to determine the concentrations of macro- and microelements in water samples. The obtained results were compared with the maximum allowed concentrations of elements specified by the national Regulation on hygienic quality of drinking water, as well as the recommendations of the World Health Organization (WHO) and the US Environmental Protection Agency (EPA). The analysed waters were low-mineralized (<1000 mg/L), calcium waters, with low sodium content. The concentrations of all tested elements in the water samples were within the allowed values. There were obvious differences in chemical composition between surface water samples and groundwater samples. All tested waters can be safely used for irrigation, because the risk of soil salinization, sodium accumulation and harmful effects of boron on crops was assessed as insignificant.

Keywords: microelements, macroelements, water quality, ICP-OES analysis, water supply system, Požega

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Multi-elementalna analiza realnih uzoraka vode sa teritorije Požege, Srbija

Izvod

Cilj ovog rada bio je ispitivanje kvaliteta realnih uzoraka vode za piće, prikupljenih sa teritorije grada Požege i okolnih seoskih naselja. Za određivanje koncentracije makro- i mikroelemenata u uzorcima vode korišćena je analitička tehnika induktivno kuplovana plazma sa optičkom emisionom spektrometrijom, ICP-OES. Dobijeni rezultati upoređivani su sa maksimalno dozvoljenim kocentracijama elemenata propisanim nacionalnim Pravilnikom o higijenskoj ispravnosti vode za piće, kao i preporukama Svetske zdravstvene organizacije (WHO) i Američke agencije za zaštitu životne sredine (EPA). Analizirane vode su malomineralizovane (<1000 mg/L), kalcijumskog tipa i sa niskim sadržajem natrijuma. Sadržaj svih ispitivanih elemenata u uzorcima vode bio je u granicama dozvoljenih vrednosti. Konstatovano je da postoje očigledne razlike u makro- i mikrokomponentnom hemijskom sastavu između uzoraka površinske vode i uzoraka podzemne vode. Ispitivane vode mogu bezbedno da se koriste u meliorativne svrhe, jer je rizik od zasoljavanja zemljišta, nagomilavanja natrijuma i štetnog uticaja bora na biljne kulture procenjen kao neznatan.

Ključne reči: mikroelementi, makroelementi, kvalitet vode, ICP-OES analiza, vodovodni sistem, Požega

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Muhammed Ernur Akiner1, İlknur Akiner2, Nurdan Akiner3, Valentina Zileska Pancovska4

1Akdeniz University, Vocational School of Technical Sciences, Antalya, Turkey, 2Akdeniz University, Department of Architecture, Faculty of Architecture, Antalya, Turkey, 3Akdeniz University, Department of Radio, Television and Cinema, Faculty of Communication, Antalya, Turkey, 4University “Ss. Cyril and Methodius”, Technology and Organization of Construction, Faculty of Civil Engineering, Skopje, Republic of North Macedonia

Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
https://doi.org/10.5937/zasmat2201068A

Zastita Materijala 63 (1)
68 –  78  (2022)

 

Using wood as a new generation building material in the context of sustainable development

Abstract

Wood is a natural resource that is renewable, easily recoverable and stores carbon dioxide, making wood constructions a feasible alternative to attaining significant sustainability targets. In the ’90s, technological attendees invented the laminated wood beams, and it begins to apply the ingenious truss solved principle to the building structures of laminated and plywood. A new generation hybrid construction method dubbed the Urban Timber (UT) System was designed to support the timber buildings based on the diagnostic vulnerabilities of wooden structures. The system was defined and demonstrated while taking into account structural behavior, architectural value. Everything else is left to the designer’s discretion, his sensitivity, and, above all, his ability to leverage technology from the many advantages and many-sided. The research seeks to inform future generations about the predicted sustainable features of wooden structures, which are touchstones of the global construction industry, under the usual circumstances of a new industry. To that end, it has proven why industrialized timber building systems are a fundamental problem in the context of the present environmental, social, and psychological discussion and the utilization of distinct construction approaches using sustainable materials. Timber is seen as the future building material, according to the findings.

Keywords: Wood; Construction Material; Sustainability; Human Psychology

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Korišćenje drveta kao građevinskog materijala nove generacije u kontekstu održivog razvoja

Izvod

Drvo je prirodni resurs koji je obnovljiv, lako povrativ i skladišti ugljen-dioksid, čineći drvene konstrukcije izvodljivom alternativom za postizanje značajnih ciljeva održivosti. Devedesetih godina prošlog veka, tehnološki polaznici su izmislili lamelirane drvene grede i počelo je da se primenjuje  princip rešenih rešetki na građevinske strukture od laminata i šperploče. Metoda hibridne gradnje nove generacije nazvana Urban Timber (UT) sistem je dizajniranja da podrži drvene zgrade na osnovu dijagnostičke ranjivosti drvenih konstrukcija. Sistem je definisan i demonstriran uzimajući u obzir ponašanje konstrukcije, arhitektonsku vrednost. Sve ostalo je prepušteno dizajnerskom nahođenju, njegovoj osetljivosti i, pre svega, njegovoj sposobnosti da iskoristi tehnologiju iz mnogih prednosti i mnogostranosti. Istraživanje nastoji da informiše buduće generacije o predviđenim održivim karakteristikama drvenih konstrukcija, koje su kamen temeljac globalne građevinske industrije, u uobičajenim okolnostima nove industrije. U tom cilju, dokazano je zašto su industrijalizovani sistemi drvenih građevinskih objekata fundamentalni problem u kontekstu sadašnje ekološke, društvene i psihološke diskusije i korišćenja različitih pristupa građenju koristeći održive materijale. Drvo se, prema nalazima, vidi kao budući građevinski materijal.

Ključne reči: drvo; građevinski materijal; održivost; humana psihologija

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Olga Myronova1, Vyacheslav Goryany2,3*

1University of Duisburg-Essen, Institute for Technology of Metals, Duisburg, Germany, 2Buch Business Center GmbH, Siegen, Germany,3Institute of Applied Materials Technology at the University of Duisburg-Essen, Duisburg, Germany

Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
https://doi.org/10.5937/zasmat2201079M

Zastita Materijala 63 (1)
79 – 88  (2022)

 

Disorders of magnesium alloy injection molding

Abstract

The feed problems in the injection molding of different magnesium alloys were investigated and explained. The examinations carried out with magnesium alloys AZ91D, ZC63 and MRI230D have shown that in addition to the known causes, other factors can also affect the draw-in disturbance. Those are following: a contaminated granulate, the unevenness and size of fine particles, a low-melting eutectic and the bevels that are used to reinforce magnesium alloys. The causes of disturbance factors that occur were analyzed and solutions were developed to eliminate and avoid them

Keywords: injection molding, magnesium granulate, C-fiber, feeding problems, microstructure, intermetallic phase

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Poremećaji pri injekcionom brizganju legura magnezijuma

Izvod

Istraženi su i objašnjeni problemi pri injekcionom brizganju različitih legura magnezijuma. Ispitivanja sprovedena sa legurama magnezijuma AZ91D, ZC63 i MRI230D su pokazala da pored poznatih uzroka, na poremećaj pri injekcionom brizganju mogu uticati i drugi faktori, kao što su kontaminacija granulata, neravnine i veličina finih čestica, eutektikumi sa niskom tačkom topljenja i vlakna koja se koriste za ojačavanje legura magnezijuma. Analizirani su uzroci faktora poremećaja koji nastaju i razvijena su rešenja za njihovo otklanjanje i izbegavanje.

Ključne reči: brizganje, magnezijum granulat, C-vlakno, doziranje, mikrostruktura, intermetalna faza

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Ubanozie Julian Obibuike, Stanley Toochukwu Ekwueme*, Nnaemeka Princewill Ohia, Onyejekwe Ifeanyi Michael

Federal University of Technology Owerri, Department of Petroleum Engineering, Nigeria

Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
https://doi.org/10.5937/zasmat2201089O
Zastita Materijala 63 (1)
89 – 100  (2022)

 

Modeling of GTL-Power coproduction as a means of optimisation of GTL plants

Abstract

Gas-to-Liquids (GTL) technologies have the potential to convert associated flare gases into premium transport liquids, creating a market for the otherwise stranded resource. However, the capital cost of GTL plants has over the years hampered the choice of the project. The drive for GTL is improved by optimization of the plant such that its efficiency and profitability is increased. One such notable improvement in GTL plant configuration is the integration of power production unit in the GTL process plant such that GTL liquids production and electricity production can occur concurrently in the same plant. This method generally called GTL-power co-production will increase the overall efficiency and profitability of existing GTL plant process and present ways to economically optimize the heat loss through the by-product streams (steam and flue gas streams). The utilization of the by-product streams will account for reductions in thermal inefficiencies within the GTL plant process. In this work, additional unit is added to the 863.3 m3/d GTL product plant configuration to utilize the by-product steam stream for electricity generation. This additional electricity unit generated 10 MW of electricity increasing the net present value (NPV) of the plant by 4.72% while the net cash recovery (NCR) increased by 3.87%. Furthermore the pay-out time reduced by 2%. The GTL-Electricity co-production has proven to be a means of optimizing GTL plant, having capability to yield more profits due to reduced capital and operational expenses than if the plants were operated separately.

Keywords: Gas-to-liquids, electricity, Co-production, Fischer-Tropsch, Waste heat

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Modeliranje GTL-koprodukcije energije kao sredstvo za optimizaciju GTL  postrojenja

Izvod

Tehnologije Gas-to- Liquids (GTL) imaju potencijal da pretvore povezane gasove iz baklje u premium transportne tečnosti, stvarajući tržište za inače nasukan resurs. Međutim, kapitalni troškovi GTL postrojenja su tokom godina ometali izbor projekta. Pogon za GTL je poboljšan optimizacijom postrojenja tako da se poveća njegova efikasnost i profitabilnost. Jedno takvo značajno poboljšanje u konfiguraciji GTL postrojenja je integracija jedinice za proizvodnju energije u GTL procesno postrojenje tako da se proizvodnja GTL tečnosti i proizvodnja električne energije mogu odvijati istovremeno u istom postrojenju. Ovaj metod koji se generalno naziva GTL-energetska koprodukcija će povećati ukupnu efikasnost i profitabilnost postojećeg procesa GTL postrojenja i predstaviti načine za ekonomičnu optimizaciju gubitka toplote kroz tokove nusproizvoda (tokove pare i dimnih gasova). Korišćenje tokova nusproizvoda će uzeti u obzir smanjenje termičke neefikasnosti u procesu GTL postrojenja. U ovom radu, dodatna jedinica je dodata konfiguraciji proizvodnog postrojenja od 863,3 m3/d GTL kako bi se tok pare nusproizvoda koristio za proizvodnju električne energije. Ova dodatna jedinica električne energije proizvela je 10 MW električne energije povećavajući neto sadašnju vrijednost (NPV) postrojenja za 4,72%, dok je neto gotovinski povrat (NCR) povećan za 3,87%. Pored toga, vreme isplate je smanjeno za 2%. Koprodukcija GTL-Electriciti se pokazala kao sredstvo za optimizaciju GTL postrojenja, imajući sposobnost da donese više profita zbog smanjenih kapitalnih i operativnih troškova nego kada bi postrojenja radila odvojeno.

Ključne reči: gas-tečnost, električna energija, koproizvodnja, Fišer-Tropš, otpadna toplota

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