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Fighting Wound Infections: Innovative Activated Charcoal-Based Biocomposite with Immobilized Probiotics
No full textWorld Health Organization (WHO) finds antibiotic resistance to be one of the
biggest threats to global health, food security and development today.
Consequently, new innovative therapies for antibiotic-resistant infections are
urgently needed. The two-year ProHealingAC project, funded by the Science Fund
of the Republic of Serbia, aims to develop novel biocomposite (BCs) based on
activated charcoal (AC) cloth and different probiotic microorganisms in order to
achieve their synergetic activity for efficient and sustained local delivery of
bioactive agents directly into the wound area. Functionality of developed BCs will
be comprehensively characterized in vitro and in vivo in animal wound model. In
vitro characterisation will include investigation of release profiles of probiotic
microorganisms, BCs inhibitor activity against relevant wound pathogens and their
modulation activity of immune cells. Furthermore, through efficient dissemination
and communication of the results, ProHealingAC project will help raise people's
awareness of the importance of the rational use of antibiotics which is crucially
important since the antibiotic resistance is considere
Enhancing seed germination of Ocimum basilicum by Bacillus spp.
No full textBasil (Ocimum basilicum L.) is widely used in traditional medicine, pharmaceuticals, cosmetics, nutraceuticals, and food industries due to its aromatic profile and health benefits from its phenolic and flavonoid compounds. It is also a common spice for enhancing the aroma and flavour of meals in various cultures. Treating seeds with selected PGP (plant growth promoting) bacteria can enhance germination efficiency by inducing a physiological state favourable for seed germination through various mechanisms, such as nutrient solubilisation, production of growth hormones, and biocontrol of pathogens. Also, bio-inoculants based on these beneficial bacteria could reduce the dependency on chemical fertilizers and pesticides, thereby mitigating environmental pollution and promoting soil health. Therefore, the aim of this research was a preliminary evaluation of the effects of Bacillus spp. on seed germination of basil in vitro. Seed germination test was performed by filter paper methods on Petri dishes. Basil seeds were treated by Bacillus spp. soil isolates (BHC 2.3 and BHC 2.4), by soaking seeds in overnight bacterial culture. Bacterial isolates were selected based on their previously determined antifungal activity against different Fusarium phytopathogens and the ability to produce indole-3-acetic acid (IAA). After 10 days of experiment, the relative seed germination index (RSGI%) was determined by comparing the number of germinated seeds in treated seeds and untreated control. Results showed that basil seeds treated by isolate BHC 2.4 and BHC 2.3 had RSGI values of 108.69% and 96.65%, respectively. These results indicate the potential of selected Bacillus spp. isolates to enhance germination of basil seeds. Future research should focus on optimizing the application methods and formulations of bio-inoculants based on Bacillus spp. to maximize their effectiveness under semi-controlled conditions and field experiments in order to offer alternative approaches in sustainable agricultural practices
Sol–Gel Derived Alumina Particles for the Reinforcement of Copper Films on Brass Substrates
No full textThe aim of this study is to provide tailored alumina particles suitable for reinforcing themetal matrix film. The sol–gel method was chosen to prepare particles of submicron size and to controlcrystal structure by calcination. In this study, copper-based metal matrix composite (MMC) films aredeveloped on brass substrates with different electrodeposition times and alumina concentrations.Scanning electron microscopy (FE-SEM) with energy-dispersive spectroscopy (EDS), TEM, and Xray diffraction (XRD) were used to characterize the reinforcing phase. The MMC Cu-Al2O3 filmswere synthesized electrochemically using the co-electrodeposition method. Microstructural andtopographical analyses of pure (alumina-free) Cu films and the Cu films with incorporated Al2O3particles were performed using FE-SEM/EDS and AFM, respectively. Hardness and adhesionresistance were investigated using the Vickers microindentation test and evaluated by applying theChen–Gao (C-G) mathematical model. The sessile drop method was used for measuring contactangles for water. The microhardness and adhesion of the MMC Cu-Al2O3 films are improved whenAl2O3is added. The concentration of alumina particles in the electrolyte correlates with an increasein absolute film hardness in the way that 1.0 wt.% of alumina in electrolytes results in a 9.96%increase compared to the pure copper film, and the improvement is maximal in the film obtainedfrom electrolytes containing 3.0 wt.% alumina giving the film 2.128 GPa, a 134% hardness value ofthat of the pure copper film. The surface roughness of the MMC film increased from 2.8 to 6.9 timescompared to the Cu film without particles. The decrease in the water contact angle of Cu films withincorporated alumina particles relative to the pure Cu films was from 84.94◦to 58.78
Kolona sa vibracionom mešalicom – fundamentalna istraživanja i primena u Srbiji od 1970. do 2020. godine
No full textIn the group of multiphase contactors and reactors, an important place belongs to reciprocating plate columns (RPCs), which consist of a set of perforated plates fixed on a carrier (the so-called reciprocating or vibrating agitator) moving periodically up and down through a column. This construction maximizes the positive effects of mechanical agitation and minimizes or eliminates the adverse effects characteristic of column-type contactors and reactors. In RPCs, the highest dispersed-phase holdup is achieved at a lower dispersed-phase velocity due to the influence of mechanical agitation on the bubble or drop comminution. Therefore, this device can be the most acceptable contactor or reactor for performing complex actions in multiphase systems. The paper reviews the fundamental research and application of RPCs in Serbia in the last fifty years, from 1970 to 2020. Hydrodynamic and mass-transfer characteristics are analyzed, such as the pressure variation at the column bottom, power consumption, dispersed-phase holdup, axial dispersion, liquid mass transfer coefficient, specific interfacial area, and volumetric mass transfer coefficient. The use of RPCs as reactors in bioprocesses and biodiesel production processes is also discussed. © 2024, Association of the Chemical Engineers of Serbia.U grupi višefaznih kontaktora i reaktora, značajno mesto zauzima reaktor sa vibracionom mešalicom
(RVM) koji se sastoji od niza perforiranih pločica pričvršćenih na zajedničkom vratilu, koje se kreću goredole. Ovakva konstrukcija reaktora maksimizira pozitivne efekte mehaničkog mešanja i minimizira ili
elimiše negativne efekte karakteristične za kontaktore i reaktore kolonskog tipa. U RVM, najveće
zadržavanje dispergovane faze postiže se pri njenoj manjoj brzini strujanja zbog uticaja mehaničkog
mešanja na usitnjavanje mehurova ili kapi. Zato ovaj uređaj može biti najprihvatljiviji kontaktor za
izvođenje složenih procesa u višefaznim sistemima. U radu su opisana fundamentalna istraživanja i
primena RVM u Srbiji u poslednjih pedeset godina, od 1970. do 2020. godine. Analizrane su hidrodinamičke i mesenoprenosne karakteristike, kao što su promena pritiska na dnu reaktora, snaga
mešanja, zadržavanje dispergovane faze, aksijalna disperzija, koeficijent prenosa mase u tečnosti,
specifična međufazna površina i zapreminski koeficijent prenosa mase. Takođe, opisana je primena RVM
kao reaktora u bioprocesima i procesima proizvodnje biodizela
The story behind the beginnings of linear elastic fracture mechanics (LEFM)
No full textLinear elastic fracture mechanics (LEFM) has a rich history that spans several decades. Regarding brief historical overview, in 1913, Inglis analyzed the stress concentration around elliptical holes and and cracks in plates, laying the groundwork for LEFM. In 1920, Griffith, an English aeronautical engineer, developed the first comprehensive theory of fracture mechanics during World War I. He observed that the stress needed to fracture bulk glass was much lower than the theoretical stress required to break atomic bonds. Griffith introduced the concept of microscopic flaws in the material and proposed that the product of the square root of the flow length and stress at fracture was nearly constant. He developed a thermodynamic approach to explain the relation between the stress and the size of the flaw, leading to the concept of fracture toughness G. This was a major early development in LEFM [1,2].
In the 1940s and 1950s, the understanding of fracture mechanics advanced significantly, driven by problems with brittle fracture in welded steel structures and aircraft. The Comet accidents, particulary the first three fatal crashes in1954, led to a dramatic expansion of research in this field. Orowan, a Hungarian-British metallurgist, studied the depth of plastic strain beneath cleavage facets in low carbon steel using X-ray scattering. Irwin, an American engineer, noted Orowan's result and grasped the engineering significance of extending Griffith's work, introducing the concept of the stress intensity factor K, to describe the stress field at the crack tip. Wells developed the first fracture test that fully simulated a welded plate structure, designing a special testing machine. Moreover, he introduced the 'crack tip opening displacement' concept to model fracture under condicions of large plastic deformation. This allowed LEFM to be applied more broadly to engineering problems [1-3].
The Comet disasters contributed to the development of the Paris' law, also known as Paris-Erdogan equation, which describes the relationship between the fatigue crack growth rate and the stress intensity factor range ΔK. This law formulated in the 1960s, represents a fundamental equation inLEFM and has been widely used to predict fatigue crack growth in various engineering applications [1-3].However, previously mentioned disasters prompted a shift in focus from LEFM to nonlinear mechanics, including metal plasticity and the development of the J-integral [4]
Advanced oxidation process in textile wastewater treatment using microreactor system
No full textThe paper analyses the possibility of treating textile wastewater contaminated with the synthetic dye Acid Violet 109 in a microreactor system using advanced oxidation process. Wastewater from textile industry pose a risk to the environment. Effluents this type could be treated on many different ways but many of them have toxic byproducts and have also high operation and maintenance costs. Advanced oxidation processes show success with acceptable operating and maintenance costs. Alternative solution for dealing with wastewater contaminated with dyes is treatment in microreactor systems. Treatment of simulated wastewater with Fenton’s reagent in microreactor system was investigated. Microreactor set consisted of two plunger pump units, mixer and PTFE tube. Efficiency of decolourisation has been determined, with a focus on microreactor parameters, reactants flow and molar ratio of reaction mixture.5th International Conference on Environmental Design and Health (ICED2024), 18-20 October 2024, Athens, Greece and Onlin
Heat-induced nanoparticles from pumpkin leaf protein for potential application as β-carotene carriers
No full textNanoparticles prepared by heat treatment of protein from pumpkin leaves were evaluated as potential carriers of β-carotene. White protein fraction was recovered from green juice produced by pressing the leaves, with the step of enzyme-assisted extraction (green protocol) or without it (conventional protocol). Heat treatment of white protein fractions from conventional and green protocols at 90 °C and pH 9.3 during 20 min induced formation of nanoparticles with peak diameter 18 nm and 21 nm, respectively. Due to heating, portion of β-sheets in nanoparticles from both native protein fractions decreased by approximately 15 %, associated with an increase in surface hydrophobicity-to-area ratio. Quenching constant of β-carotene for nanoparticles was increased nearly 100 times by heating the white protein fraction recovered in green protocol. Native white protein fraction from conventional protocol and corresponding nanoparticles exhibited high ability to bind β-carotene, with quenching constant 3 × 105 L/mol and 3.3 × 105 L/mol, respectively. White protein fraction from pumpkin leaves appeared to be a suitable substrate for the fabrication of nanoparticles by heat treatment, with potential application as β-carotene nanocarriers in food matrices.Supplementary information: [https://technorep.tmf.bg.ac.rs/handle/123456789/7331
A Novel Approach to Serving Plant-Based Confectionery—The Employment of Spray Drying in the Production of Carboxymethyl Cellulose-Based Delivery Systems Enriched with Teucrium montanum L. Extract
No full textIn this study, spray drying was used as a technological solution for the valorization of Teucrium montanum extract into carboxymethyl cellulose-based delivery systems (CMC), individually or in combination with collagen, guar gum, gum arabic, and kappa-carrageenan. The results showed that the process yield and morphological properties were positively influenced by the introduction of CMC binary blends. The employment of CMC resulted in a high encapsulation efficiency (77–96%) for all phenylethanoid glycosides (PGs) analyzed. Due to the low wettability of the microparticles, a relatively gradual in vitro release of the PGs was achieved. Infusion of the filling with hydrophilic T. montanum extract encapsulated in microparticles with high hydrophobic surface area proved to be a practical route for significant confectionery fortification (5–9 mg PGs per dw serving), ensuring prolonged interaction between the food matrix used and the extract under simulated gastrointestinal conditions. Based on sensory evaluation, the introduction of kudzu starch into the jelly matrix has shown a texture-modifying potential
Mn-Fe Layered Double Hydroxide Modified Cellulose-Based Membrane for Sustainable Anionic Pollutant Removal
No full textThis study aimed to investigate the adsorption of As(V), phosphate, and textile dye Acid Green 25 (AG-25) on layered double hydroxides Mn-Fe_LDH and corresponding membranes (wCell/Mn-Fe_LDH). The wCell membrane, derived from waste tobacco boxes, was formed by cross-linking of epoxy and amino modified cellulose fibers with epoxy modified Mn-Fe_LDH and lysine as cross-linker. Structural and morphological analyses were conducted for Mn-Fe_LDH and wCell/Mn-Fe_LDH. The batch system explored pH, contact time, temperature, and initial concentration effects on wCell/Mn-Fe_LDH adsorption efficiency. Adsorption capacities of 82.71, 106.9, and 130.3 mg g−1 were achieved for As(V), phosphate, and AG-25, respectively, indicating effective anionic species removal. Kinetic analysis suggested intraparticle diffusion as the rate-limiting step. Thermodynamic parameters and ionic strength effects indicated a physisorption mechanism for AG-25 and surface complexation for As(V) and phosphate. Biodegradation experiments after five adsorption/desorption cycles revealed the membrane’s decomposition, with phosphate’s strong bonding releasing essential elements valuable for soil fertilization. Effluent wastewater treatment demonstrated low environmental impact through the formation of insoluble As(V) salts and photocatalytic dye degradation.Supplementary information: [https://technorep.tmf.bg.ac.rs/handle/123456789/7333
A Comprehensive Review of the Effect of Elastane and Common Wet Processes on the Cotton and Cotton/Elastane Knitted Fabrics’ Properties and Revalorization of Fabric Waste
No full textThis paper represents a comprehensive review of the effect of elastane and common wet processes (bleaching, dyeing, and softening) on the properties of 100% cotton and half or full plated cotton/elastane single jersey knitted fabrics. The fabrics were characterized in terms of their structural (fabric weight, thickness, and stitch density), comfort (air permeability and water vapor resistance), mechanical (stiffness, bursting elongation, and bursting strength), and antistatic (volume electrical resistivity) properties. Fabrics’ antistatic properties were further improved by in situ synthesis of Cu-based nanoparticles (CuNPs) on their surfaces. Such fabrics can be also considered as bioactive since they possessed excellent antioxidant (determined using the ABTS method) and antimicrobial (against E. Coli, S. aureus, and C. albicans) activities. The last section of this chapter is focused on proposing a novel circular economy solution for the disposal of softened cotton and cotton/elastane knitted fabric waste collected from the textile industry (i.e., after clothing cutting). For that purpose, selected fabrics were revalorized as adsorbents for the widely used textile dye Congo Red and the maximum dye adsorption was tested using isotherm models. Thereafter, the fabrics with adsorbed Congo Red dye were evaluated as antistatic and dissipative fabrics, i.e., as alternative non-metal-based conductive textiles.Part of the book series: Lecture Notes in Networks and Systems (LNNS, volume 792)