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Development of S500MC grade microalloyed steel in HBIS Serbia hot strip mill
No full textThe object of this paper is the development of hot rolled coils of microalloyed S500MC grade steel in
6.00x1500 mm and 12.00x1500 mm dimensions in HBIS Serbia hot strip mill, according to European
Standard EN 10149-2:2013. The basis for this development was present experience in production of grade
S460MC. The first step was design of chemical composition. This modification required the increase of the
content of microalloying elements. The second step included modification of parameters of rolling
technology (transfer bar thickness, reheating temperature/time etc.). Finally, after cooling and coiling, hot
rolled strips were tested by means of tensile testing and Charpy impact toughness. Results show that in all
cases yield strength, ultimate tensile strength, elongation and Charpy impact toughness satisfy requirements
from EN 10149-2:2013. Also, due to difference in cooling rate for thin (6.00 mm) and thick (12.00 mm) hot
strips, a driving force for nucleation of ferrite grains will be different. Therefore, chemical compositions for
the same grade, but different thickness have to be different in order to compensate the lower driving force for
ferrite nucleation in 12.0 mm strip. Slightly increased content of Nb and V in 12.00 mm hot strip provided
good mechanical properties
Mimicking physiology: Perfusion bioreactor characterisation of the polyphenol-functionalized hydrogels for controlled drug delivery
No full textUnderstanding the characteristics and release behavior of therapeutic compounds from
complex controlled-release systems under physiological conditions remains a challenge in
drug development. Biomimetic bioreactors provide a more accurate and reliable platform
by replicating the dynamic physiological conditions of targeted tissues and applications.
In this study, we aimed to develop a localized anticancer drug delivery system based on
methacrylate chitosan hydrogels (MCH) functionalized with green tea polyphenols (GTP) or
tannic acid (TA). We hypothesized that MCH prepared via UV-curing and subsequently
functionalized with GTP or TA, would exhibit enhanced mechanical stability and enable the
effective, sustained release of bioactive compounds. ..
Istraživanje potencijala agroindustrijskog lignoceluloznog otpada za proizvodnju lakaze gljivom bele truleži i sveobuhvatna karakterizcija lakaze
No full textAgro-industrial waste is commonly discarded or incinerated, leading to significant environmental pollution.
However, this waste contains chemical properties that allow for its beneficial reuse. For example, certain waste
products can serve as substrates for complex fermentation processes in biotechnology. Utilizing agricultural
wastes for laccase production through white-rot fungi is an effective approach to both lower production costs and
mitigate environmental pollution. Additionally, laccase-mediated delignification improves the nutritional quality
of agro-industrial byproducts, making them valuable as animal feed or soil fertilizers. This study explored the
potential of four different agro-industrial lignocellulosic wastes—brewer's spent grain, soybean meal, sunflower
meal, and spent coffee grounds—for laccase production by the white-rot fungus Coriolopsis trogii 2SMKN.
Following the production process, the laccase was concentrated and subjected to comprehensive
characterization, including determination of molecular weight, pH and temperature optimum, pH and thermal
stability, storage stability, and testing the influence of different cation concentrations on enzyme activity. The
results showed that all four substrates supported fungal growth and development, though they differed in their
ability to induce the production of laccase. The most effective substrate for laccase production was brewerʼs
spent grain, yielding the highest laccase activity of 47.43 IU/g. In contrast, the lowest laccase activity of 2.28
IU/g was observed with spent coffee grounds. The produced laccase exhibited a molecular weight of
approximately 60 kDa, with maximum activity at 70 °C and pH 5.5. It was most stable at 60 °C, retaining
66.24% of its initial activity after 360 min of incubation, while its stability decreased at 80 °C. In terms of pH
stability, laccase was most stable at its optimal pH of 5.5, where it retained 55.1% of its initial activity after 120
min. Over a 12-month storage period at -20 °C, laccase stability declined, with only 30.21% of its original
activity remaining after one year. Copper ions, in concentration ranging from 0.5 to 5 mM, exhibited an
inhibitory effect on laccase activity, while magnesium and calcium ions in the same concentration range slightly
stimulated its activity. Accordingly, these results highlight that agro-industrial waste is an excellent substrate for
laccase production, offering promising catalytic performanceAgroindustrijski otpad se uglavnom odbacuje ili spaljuje, što dovodi do značajnog zagađenja životne sredine.
Međutim, ovaj otpad odlikuju hemijska svojstva koja omogućavaju njegovu korisnu ponovnu upotrebu. Na
primer, određeni otpadni proizvodi mogu poslužiti kao supstrati za složene procese fermentacije u biotehnologiji.
Korišćenje poljoprivrednog otpada za proizvodnju lakaze gljivama bele truleži je efikasan pristup za niže
troškove proizvodnje i ublažavanje zagađenja životne sredine. Pored toga, delignifikacija posredovana lakazom
poboljšava nutritivni kvalitet agroindustrijskih nusproizvoda, čineći ih vrednim kao stočnu hranu ili đubrivo za
zemljište. Ova studija je istraživala potencijal četiri različita agroindustrijska lignocelulozna otpada — otpadnog
pivskog ječma, sojine sačme, suncokretove sačme i otpadne kafe — za proizvodnju lakaze gljivom bele truleži
Coriolopsis trogii 2SMKN. Nakon procesa proizvodnje, lakaza je koncentrovana i podvrgnuta sveobuhvatnoj
karakterizaciji, uključujući određivanje molekulske mase, pH i temperaturnog optimuma, pH i termičke
stabilnosti, stabilnosti tokom skladištenja i ispitivanje uticaja različitih koncentracija katjona na aktivnost
enzima. Rezultati su pokazali da sva četiri supstrata podržavaju rast i razvoj gljive, iako su se razlikovali u svojoj
sposobnosti da podstaknu proizvodnju lakaze. Najefikasniji supstrat za proizvodnju lakaze bio je otpadni pivski
ječam, koji je indukovao najveću aktivnost lakaze od 47,43 IU/g. Nasuprot tome, najniža aktivnost lakaze od
2,28 IU/g primećena je kod otpadne kafe. Proizvedena lakaza je imala molekulsku masu od približno 60 kDa, sa
maksimalnom aktivnošću na 70 °C i pH 5,5. Bila je najstabilnija na 60 °C, zadržavajući 66,24% svoje početne
aktivnosti nakon 360 minuta inkubacije, dok je njena stabilnost smanjena na 80 °C. U pogledu pH stabilnosti,
lakaza je bila najstabilnija pri svom optimalnom pH od 5,5, gde je zadržala 55,1% svoje početne aktivnosti
nakon 120 minuta. Tokom perioda skladištenja od 12 meseci na -20 °C, stabilnost lakaze je opadala, te je samo
30,21% njene početne aktivnosti preostao nakon jedne godine. Joni bakra, u koncentraciji od 0,5 do 5 mM, imali
su inhibitorni efekat na aktivnost lakaze, dok su joni magnezijuma i kalcijuma u istom opsegu koncentracija
blago stimulisali njenu aktivnost. Shodno tome, ovi rezultati naglašavaju da je agroindustrijski otpad odličan
supstrat za proizvodnju lakaza sa obećavajućim katalitičkim performansama
Terpene-Based Biofuel Additives (Citral, Limonene, and Linalool) with Chloroform: Experimental and Modeling Study of Volumetric and Transport Properties
No full textIn this paper, the thermodynamic properties of terpene mixtures were investigated because they represent a promising group of compounds, usually extracted from biomass, with their most notable application as fuel performance enhancers. The densities, viscosities, refractive indices, and ultrasonic speeds of sound were measured for three binary mixtures, citral + chloroform, limonene + chloroform, and linalool + chloroform, across the full composition range at temperatures between 288.15 K and 323.15 K under atmospheric pressure. Using experimental data, excess molar volumes, viscosity deviations, refractive index deviations, and isentropic compressibility, deviations were calculated. Additionally, properties such as partial molar volumes, excess partial molar volumes, partial molar volumes at infinite dilution, and apparent molar volumes were derived. The excess and deviation properties were analyzed using the Redlich–Kister equation. A single mathematical model, the Heric–Brewer–Jouyban–Acree model, was used to represent densities, viscosities, refractive indices, and ultrasonic speeds of sound. The results obtained in this work suggest that dispersive interactions dominate in the limonene and linalool binary mixtures, while hydrogen bonding plays a significant role in the citral + chloroform system. In summary, dispersive interactions are dominant in nonpolar systems like limonene and linalool, while hydrogen bonding significantly affects the citral-chloroform mixture, where the polar groups in citral interact with chloroform molecules. These differences in intermolecular forces help explain the distinct behavior of each mixture. The modeling outcomes demonstrated that the Heric–Brewer–Jouyban–Acree model accurately correlated the experimental thermodynamic properties, with average percent deviations below 1% for all three systems
Sprovođenje hitnih mera za poboljšanje efikasnosti uklanjanja nikla iz vode na postojećem postrojenju za prečišćavanje vode
No full textIn this paper, based on the data of the Ribnica accumulation (Serbia), and the required quality of raw and treated water, an optimal solution for improving and optimization of the technology of water purification to drinking quality at a water treatment plant (WTP) in Zlatibor, Serbia, was proposed to ensure maximum efficiency and flexibility in system operation. Analysis of water quality has shown that after the treatment at the plant, all parameters were within the respective maximum available concentrations (MAC) stipulated by the Rulebook on the hygienic suitability of potable water of the Republic of Serbia, except for the nickel content. The paper presents the results of the nickel removal using multiple laboratory tests as well as at the WTP to achieve the best procedure for water treatment. In accordance with the results obtained the water quality problem in terms of the nickel removal was solved and the required effects are obtained (nickel content below the MAC, i.e. <0.02 mg dm-3).Projektovanje postrojenja za prečišćavanje vode (PPV) podrazumeva kompleksnu analizu i primenu
kriterijuma projektovanja zajedno sa praktičnim iskustvom. Osnovni kriterijumi standardnog projektovanja
obuhvataju kapacitet, kvalitet sirove i prečišćene vode, lokaciju postrojenja za prečišćavanje vode i skup
prihvatljivih, proverenih tehnologija. Kombinovanjem kriterijuma pouzdanosti sistema sa tehnoekonomskim pokazateljima moglo bi se dobiti optimalno procesno rešenje za nova postrojenja, kao i za
unapređenje procesa u postojećim postrojenjima. U ovom radu, na osnovu podataka iz akumulacije
Ribnica, Srbija, i zahtevanog kvaliteta sirove i prečišćene vode, predloženo je optimalno rešenje za
unapređenje i optimizaciju tehnologije prečišćavanja vode do kvaliteta za piće na PPV na Zlatiboru, Srbija,
kako bi se osigurala maksimalna efikasnost i fleksibilnost u radu sistema. Analiza kvaliteta vode pokazala je
da su nakon tretmana u postrojenju svi parametri bili u granicama odgovarajućih maksimalno dozvoljenih
koncentracija propisanih Pravilnikom o higijenskoj ispravnosti vode za piće Republike Srbije, osim sadržaja
nikla. U radu su prikazani rezultati uklanjanja nikla primenom višestrukih ispitivanja u laboratoriji i na PPV
radi uspostavljanja najbolje procedure za tretman vode. Prema dobijenim rezultatima, rešen je problem
kvaliteta vode u pogledu uklanjanja nikla i ispunjeni su zahtevani uslovi (sadržaj nikla ispod maksimalne
dozvoljene koncentracije < 0.02 mg dm-3)
Модификовање карактеристика површине и фотокаталитичке активности чистог и g-C3N4 допираног кисеоником помоћу плазма поступка
No full textGraphitic carbon nitride (CN) is a non-metallic semiconductor with applications in photocatalysis, including the photocatalytic reduction of Cr(VI) under visible irradiation. To improve its intrinsic properties, two modification strategies were applied: i) oxygen doping by co-calcination of urea with two different amounts of oxalic acid and ii) dielectric barrier discharge (DBD) plasma treatment. The plasma treatment was applied to pristine and previously oxygen-doped CNs. The properties of the photocatalysts were studied by XRD, FTIR, FESEM, EDS, PL and DRS analysis, as well as by determination of the number of acidic surface functional groups. Both modification methods increased the oxygen content: during oxygen doping, nitrogen was replaced by oxygen in the lattice, while during plasma treatment, oxygen-containing functional groups were introduced at the surface. Plasma treatment of oxygen-doped CNs facilitated surface functionalisation due to the open heptazine ring structure. Oxygen doping narrowed the band gap, which was further slightly reduced by subsequent plasma treatment, thereby lowering the oxidation and reduction potentials. Although the absorption of visible light was improved, the reduction of the band gap resulted in a reduced activity for the photocatalytic reduction of Cr(VI). The best results were obtained with plasma-treated pure CN, due to the increased content of oxygen-containing surface groups, which led to a slightly reduced recombination rate of charge carriers.Графитни угљеник(IV)-нитрид (CN) представља полупроводник изграђен од неметала, који има широку примену у фотокатализи, укључујући и фотокаталитичку редукцију Cr(VI) под дејством видљивог зрачења. Како би се унапредилa својства CN синтетисаног термичком полимеризацијом урее, примењене су две методе модификације: a) допирање кисеоником поступком ко-калцинације урее са две различите количине оксалне киселине, и б) плазма третман диелектричним баријерним пражњењем (енгл. dielectric barrier discharge (DBD)). Плазма третман је примењен на чист и на CN допиран кисеоником. За карактеризацију фотокатализатора коришћене су XRD, FTIR, FESEM, EDS, PL и DRS методе анализе, као и поступак за одређивање броја површински киселих функционалних група. Резултати су показали да је садржај кисеоника повећан у оба случаја: током допирања кисеоником долази до замене азота кисеоником у решетки, док током плазма третмана кисеоничне функционалне групе се везују на површини. Такође, плазма третманом претходно допираних узорака су функционалне групе које садрже О лакше везане због „отворeног“ хептазинског прстена. Допирање кисеоником је довело до сужавања забрањене зоне, које је било још више изражено након плазма третмана допираних узорака, при чему су смањени и оксидациони и редукциони потенцијал узорака. Иако је побољшана апсорпција видљивог зрачења, ово је допринело смањеној активности за фотокаталитичку редукцију Cr(VI). Најбољи резултати су постигнути са плазма третираним чистим CN, због повећаног садржаја функционалних група које садрже кисеоник што је допринело мањој брзини рекомбинације носилаца наелектрисања
Development of multifunctional polyvinyl alcohol–activated charcoal dressings for advanced wound management
No full textIntroduction: Wound care continues to pose a significant clinical and
socioeconomic challenge. Around 2% of the global population suffers from
“hard-to-heal” wounds that are frequently colonized by microorganisms and
are prone to infection. Efficient management of these wounds has shifted
toward polymer-based dressings that maintain a moist environment through
fluid absorption, while also enabling controlled drug release, antimicrobial
protection, and sometimes odor control. Synthetic polymers such as
polyvinyl alcohol (PVA) are commonly used components of wound
dressings due to their reproducibility, tunable properties, and mechanical
stability. The incorporation of activated charcoal (AC) has gained attention
for its ability to remove odors and microbial toxins. In this study, we
developed a PVA–AC-based dressing functionalized with either silver ions
(SI) or povidone-iodine (PI), aiming to combine exudate management,
sustained antimicrobial activity, malodor control, and structural integrity..
Optimizing Ex Vivo Joint Models: The Role of Glucose and Oxygen in Tissue Preservation
No full textBackground: Monocultures of chondrocytes or cartilage fail to mimic the joint's complexity, where cartilage
interacts with synovium and subchondral bone. Additionally, variability in glucose and oxygen levels across
studies, with no standard protocol for high- or low-glucose DMEM, affects reproducibility and clinical
translation. The aim of the present study is to develop an ex vivo co-culture system with osteochondral and
synovium tissues and investigate how glucose levels influence an ex vivo joint model under varying oxygen
conditions. ..
Flax plain weft-knitted fabrics: impact of pilling on structure and electrical resistivity
No full textThe objective of this research is to explore structural characteristics (loop length and stitch density) and electrical resistivity (volume and surface) of plain weft-knitted flax fabrics, both before and after pilling. Pilling in these fabrics was conducted using a Martindale device equipped with two abrasives: the knitted fabric under examination and a wool woven fabric. A decrease in loop length and stitch density of the knitted fabrics after pilling with both abrasives was noted, except for loop length in two lightweight samples. Before pilling, a reducing loop length and increasing other structural characteristics of the fabrics correlated with reduced resistivity. After pilling, all examined samples displayed decreased volume and surface electrical resistivity, except the sample characterized by the highest structural values, which displayed increased surface electrical resistivity after pilling with both abrasives. Fabrics subjected to pilling with the wool woven fabric showcased lower values in both volume and surface electrical resistivity
Bio-Inspired Antimicrobial Approaches for Topical Wound Care in the Era of Resistance
No full textWound infections, particularly those associated with chronic wounds and biofilms, represent a major challenge in
clinical care due to delayed healing, increased morbidity, and rising antimicrobial resistance. While conventional
antimicrobials such as antibiotics, antiseptics, and silver-based agents remain key therapeutic tools, their efficacy
is increasingly compromised by microbial resistance, and limited activity against biofilms. The urgent need for
alternative strategies has directed research towards bio-inspired antimicrobial approaches that offer novel
mechanisms of action and reduced resistance potential. This paper explores three promising categories of bioinspired
antimicrobial approaches for wound healing: antimicrobial peptides, microbiota-based, and
bacteriophage-based therapies. Antimicrobial peptides mimic innate immune defence and possess broad-spectrum
antimicrobial and immunomodulatory activity, although their therapeutic use is hindered by enzymatic
degradation, cytotoxicity, and production costs. Probiotics and postbiotics contribute to wound healing by restoring
microbial balance, inhibiting pathogens, and modulating host immunity. Notably, postbiotics, non-viable
microbial components, offer enhanced stability and safety, making them attractive for topical applications. Phage
therapy, involving the use of viruses that selectively infect bacteria, demonstrates high specificity and efficacy
against multidrug-resistant pathogens and biofilms, though regulatory and manufacturing challenges persist. To
enhance the stability, bioavailability, and targeted delivery of these agents, advanced biomaterials such as
hydrogels, polymer-based matrices, and nanocomposites are being developed. These delivery platforms improve
local retention, reduce systemic toxicity, and enable the controlled release of antimicrobial agents. In conclusion,
bio-inspired antimicrobials present a promising frontier for next-generation wound care. Their development could
address key limitations of current treatments and contribute to combating antimicrobial resistance. Continued
interdisciplinary research, innovation in delivery systems, and robust clinical validation are essential to facilitate
their translation into routine clinical practice