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Barbotažna kolona sa istostrujnim tokom faza u transferzalnom magnetnom polju
No full textAn experimental study has been carried out investigating the fluidization behavior of a bubble column with a bottom magnetic particle bed controlled by an external transverse magnetic field. The magnetization-first/gas-scanning mode was applied, at up to 45 kA m-1 field intensity, with liquid superficial velocities of up to 20 mm s-1 and with a gas flowrate of up to 8 m3 h-1. Particle fractions of two different sizes of up to 1 mm were used. The focus has been both on the three-phase magnetic particle bed expansion playing the role of a gas distributor and the gas holdup of the abovepositioned two-phase section, as well as related column parameters. Piezometric measurements have been performed that provided detection of the position of the interface between the two column sections without visual observation, as well as the gas holdup in the two-phase zone. The bed expansion was strongly affected by the bed state created by the initially established liquid flow rate. The results showed that the intensity of the field applied to the magnetic solids allows control both of bed expansion and internal bed structure, so the applicability of magnetically assisted three-phase beed as a gas distributor in bubble column seems promising.U radu je dat prikaz eksperimentalnih rezultata dobijenih u barbotažnoj koloni sa magnetnom čvrstom fazom smeštenom na dnu kolone, kao raspodeljivačem dvofaznog toka gas-tečnost, pod dejstvom poprečnog magnetnog polja. Najpre je obezbeđen protok tečnosti kroz pakovani sloj čestica, zatim je takav sloj podvrgnut dejstvu magnetnog polja, a na kraju je uspostavljen protok gasa kroz sloj, koji je obezbedio uspostavljanje fluidizovanog sloja čestica. Eksperimenti su izvedeni pri intenzitetima polja do 45 kA m-1 , površinskim brzinama tečnosti do 20 mm s-1 i protocima gasa do 8 m3 h -1 . Korišcene su frakcije čestica dva različita opsega prečnika, do 1 mm. Fokus je bio na ekspanziji trofaznog sloja magnetnih čestica, koji igra ulogu distributora gasa, kao i na zapreminskom udelu gasa u dvofaznoj sekciji kolone koja se nalazi iznad trofaznog sloja, a takođe i na drugim odgovarajucim parametrima sistema. Izvršena piezometarska merenja su pokazala da je na osnovu njih moguce odrediti poziciju granice između dve sekcije u koloni bez vizuelne detekcije te pozicije, kao i određivanje sadržaja gasa u dvofaznoj sekciji kolone. Na ekspanziju sloja snažno je uticalo stanje sloja stvoreno inicijalno uspostavljenim protokom tečnosti. Rezultati su pokazali da intenzitet polja primenjenog na magnetne čestice omogucava kontrolu kako ekspanzije sloja tako i unutrašnje strukture sloja, na osnovu kojih se prepoznaje potencijalna primenljivost magnetno stabilisanog trofaznog sloja kao distributora gasa u barbotažnoj koloni
MgAl-Layered Double Hydroxide-Coated Bio-Silica as an Adsorbent for Anionic Pollutants Removal: A Case Study of the Implementation of Sustainable Technologies
No full textThe adsorption efficiency of Cr(VI) and anionic textile dyes onto MgAl-layered double hydroxides (LDHs) and MgAl-LDH coated on bio-silica (b-SiO2) nanoparticles (MgAl-LDH@SiO2) derived from waste rice husks was studied in this work. The material was characterized using field-emission scanning electron microscopy (FE-SEM/EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopic (XPS) techniques. The adsorption capacities of MgAl-LDH@SiO2 were increased by 12.2%, 11.7%, 10.6%, and 10.0% in the processes of Cr(VI), Acid Blue 225 (AB-225), Acid Violet 109 (AV-109), and Acid Green 40 (AG-40) dye removal versus MgAl-LDH. The obtained results indicated the contribution of b-SiO2 to the development of active surface functionalities of MgAl-LDH. A kinetic study indicated lower intraparticle diffusional transport resistance. Physisorption is the dominant mechanism for dye removal, while surface complexation dominates in the processes of Cr(VI) removal. The disposal of effluent water after five adsorption/desorption cycles was attained using enzymatic decolorization, photocatalytic degradation of the dyes, and chromate reduction, satisfying the prescribed national legislation. Under optimal conditions and using immobilized horseradish peroxidase (HRP), efficient decolorization of effluent solutions containing AB-225 and AV-109 dyes was achieved. Exhausted MgAl-LDH@SiO2 was processed by dissolution/precipitation of Mg and Al hydroxides, while residual silica was used as a reinforcing filler in polyester composites. The fire-proofing properties of composites with Mg and Al hydroxides were also improved, which provides a closed loop with zero waste generation. The development of wastewater treatment technologies and the production of potentially marketable composites led to the successful achievement of both low environmental impacts and circular economy implementation
The Radon Exhalation Rate and Dose Assessment of Granite Used as a Building Material in Serbia
No full textThe application of energy-saving policies in buildings could lead to a decrease in the air exchange rate in dwellings, which could consequently lead to an increase in indoor radon concentration and, therefore, to an increase in resident exposure to ionizing radiation. The aim of the research presented in this paper is to investigate radiological exposure to residents due to the usage of different granites commonly used in Serbia as a building material. From the total of 10 analysed granite samples, a wide range of radon and thoron exhalation rates were found: from <161 μBq m−2 s−1 to 5220 ± 200 μBq m−2 s−1 and from <7 mBq m−2 s−1 to 5140 ± 320 mBq m−2 s−1, respectively. Assuming a low air exchange rate of 0.2 h−1, the contribution of the measured granite material to the indoor radon concentration could go up to 150 Bq m−3. The estimated annual effective doses due to exposure to radon and thoron exhalation from the granite samples were (0.05–3.79) mSv and (<0.01–1.74) mSv, respectively. The specific activity of radionuclides ranged from 6.6 ± 0.5 Bq kg−1 to 131.8 ± 9.4 Bq kg−1 for 226Ra, from 0.5 ± 0.1 Bq kg−1 to 120.8 ± 6.5 Bq kg−1 for 232Th, and from 0.22 ± 0.01 Bq kg−1 to 1321 ± 86 Bq kg−1 for 40K. The obtained external hazard index ranged from 0.03 to 1.48, with three samples above or very close to the accepted safety limit of 1. In particular, dwellings with a low air exchange rate (causing elevated radon) could lead to an elevated risk of radiation exposure
Alat za zavarivanje trenjem alatom sa keramičkom prevlakom i hladnjakom
No full textBroj prijave: MP-2024/0002Broj i datum rešenja o priznanju prava: 2024/5563; 24.06.2024Glasnik intelektualne svojine broj 7/2024, dana 31.07.2024
Targeted modulation of myeloid regulatory cells with prostaglandin E2 ameliorates experimental autoimmune encephalomyelitis and preserves gut microbiota
No full textAutoimmune diseases, such as multiple sclerosis (MS), are impacted by disregulated myeloid cells and disbiosis in gut microbiota. Previously we identified that prostaglandin (PG)E2 is critical for the activation of myeloidderived suppressor cells (MDSCs), and their capacity to ammeliorate neuroinflammation in experimental autoimmune encephalomyelitis (EAE). However, it remained unclear how different approaches for the modulation of myeloid cells with PGE2 in EAE associate with gut microbiota composition.Special Issue: Abstract Book / 7th European Congress of Immunology ECI 2024, 1-4 September, 2024 Dublin, Irelan
Hvatač boja i postupak proizvodnje hvatača boja
No full textA dye scavenger is provided that comprises a biodegradable hydrogel formed of at least one polymer chemically cross-linked by a cross-linker. The dye scavenger removes dyes rapidly, is prepared in an environmentally friendly manner, is reusable and biodegradable and can optionally incorporate other features of laundry compositions. The dye scavenger is useful for preventing dye transfer between fabrics in laundry and for removing dyes from waste water.Broj i datum podnošenja međunarodne prijave: WO 10.12.2018 PCT/RS2018/000019Broj i datum međunarodne objave: WO 18.06.2020 WO2020/122743Datum i broj objave priznatog evropskog patenta: 19.06.2024 EP3894531 2024/25 E
Силко за траве и житарице – Нови инокулант за силирање и сенажу трава и житарица
No full textСилко за траве и житарице представља специјализовани производ,
смешу аутохтоних сојева бактерија
млечне киселине и хидролитичких
ензима (целулазе и ксиланазе) који
разграђују лигноцелулозну биомасу.
Ензими, разградњом лигноцелулозне
фракције доприносе ослобађању
додатне количине шећера, чиме се
постиже снажан раст и одржава се
оптимална комбинације корисних
бактерија млечне киселине, као и
нагли пад pH вредности што допри
носи повећању стабилности силаже
и хранљиве вредности хране. Употребом овако дизајнираних инокуланата
добија се укусна и квалитетна храна
током целе године и стабилан принос
меса и млека.Експонат је развијен у оквиру пројекта:
Иновациони ваучер: Карактеризација и
унапређивање производње за максималну продукцију бактеријских ензима
целулазе и ксиланазe.
Извор средстава из којих jе пројекат
финансиран: Фонд за иновациону
делатност Републике Србије.
Организације које су учествовале на
пројекту и развоју експоната: Технолошко-металуршки факултет, Универзитет у Београду; Иновациони центар
Технолошко-металуршког факултета
д.о.о., BIO-TECH SOLUTIONS INKUBATOR
д.о.о. Шимановци
Competitive copper, cadmium, and nickel ions removal from aqueous solution using amino-modified magnetic polymer sorbent
No full textIn this study, amino-modified magnetic polymer sorbent, mPGME-eda, was employed for the
sorption of copper (Cu2+), cadmium (Cd2+), and nickel (Ni2+) ions from aqueous solution. The
sorption was studied under competitive conditions by varying contact time and initial metal
concentration at unadjusted pH (4.2) and 298 K. It was found that sorption capacity increased with
the increase of contact time and initial metal concentration. Equilibrium sorption capacities for Cu2+ (1.20 mmol/g) and Cd2+ (1.15 mmol/g) were attained after 360 min, while for Ni2+ (1.01 mmol/g) it was reached after 90 min. It was noticed that metal ions sorption follows a pseudo-second-order kinetic model. The mechanism of sorption was found to be intra-particle diffusion-controlled with an evident influence of liquid film diffusion. Equilibrium sorption data were best fitted with the Langmuir isotherm model
A new generation of aramid fibers/poly (vinyl butyral) composites for ballistic protection: Recent development and advances
No full textIn recent times, para-aramid fabrics have become widely used in the design of composite structures for defense, automotive, and aerospace sectors, sports equipment, and other various applications. High-performance para-aramid fibers form the foundation of lightweight ballistic materials, typically as a woven fabric or a non-woven cross-plied unidirectional material, usually impregnated with a thermosetting or thermoplastic polymeric matrix. Currently, efforts are under way to enhance the impact protection performance of these composites by incorporating reinforcement such as ceramics, nanofibers, various nanoparticles, nanotubes, and their modified hybrid structures with a poly (vinyl butyral) (PVB) thermoplastic matrix. The aramid fibers reinforce the composite’s strength and thermal stability, while the PVB matrix offers flexibility, toughness and impact resistance. This survey presents the effects of adding different nanofillers and their hybrids on impact resistance and overall performance of these p-aramid fibers/poly (vinyl butyral) composites, focusing on improved elastic modulus and energy absorption following the ballistic impact and knife penetrations of the composites. Overall, incorporating hybrid nanofillers into aramid fiber/PVB composites results in materials with superior impact resistance, thus enhanced protective capabilities, making them ideal for high-performance applications
Theoretical strategy for the production of the carbamazepine polymorph V
No full textАнтиконвулзивни лек карбамазепин има преко 50 познатих форми, укључујући
5 полиморфа, при чему сваки од њих има различиту кристалну структуру и физичка
својства, што може имати значајан утицај на фармацеутску формулацију,
апсорпцију, биолошку расположивост и ефикасност лека. Кристалне структуре
полиморфа I, II, III и IV задржавају мотив у коме су два инверзано оријентисана
молекула повезана паром N–H/O водоничних веза образујући R2
2
(8) прстен (Слика
1, леви димерни мотив), док кристалну структуру полиморфа V карактеришу ланци
са једноструким N–H/O водоничним везама, ојачаним N-H/π интеракцијом (Слика
1, десни мотив). У Кембричкој структурној бази података (CSD) налазе се
архивиране 33 кристалне структуре полиморфа I, II, III и IV, a само једна кристална
структура полиморфа V, добијена из парне фазе 10,11-дихидрокарбамазепина.
Полиморф V занимљив je и због тога што се не може добити директном синтезом
или фазном трансформацијом поменутa четири полиморфа. Могући разлог за то
лежи у чињеници да је енергија интеракције у оваквом систему нижа у односу на
преостала четири полиморфа који садрже двоструку водоничну везу. Oво потврђују
и позитивне вредности стандардне промене Гибсове слободне енергије (ΔG)
израчунате за три различите температуре (298, 373 и 463 К). Екстраполацијом
израчунатих ΔG вредности, показало се да се полиморф V може добити од
полиморфа I, II, III или IV искључиво загревањем до тачке топљења (463 К), а затим
хлађењем до температуре ниже од 260 К.The anticonvulsant drug carbamazepine has over 50 known forms, including 5 polymorphs, each with a different crystal structure and physical properties, which can significantly impact pharmaceutical formulation, absorption, bioavailability, and drug efficacy. The crystal structures of polymorphs I, II, III, and IV retain the motif where two molecules related by inversion are linked by a pair of N–H/O hydrogen bonds firming an R2 2 (8) ring (Figure 1, left dimer motif), while the crystal structure of polymorph V is characterized by chains with a single N–H/O hydrogen bond, strengthened by N-H/π interaction (Figure 1, right motif). The Cambridge Structural Database (CSD) archives 33 crystal structures of polymorphs I, II, III, and IV, with only one crystal structure of polymorph V obtained from the vapor phase of 10,11-dihydrocarbamazepine. Polymorph V is interesting because it cannot be obtained by direct synthesis or phase transformation of the aforementioned four polymorphs. A possible reason for this lies in the fact that the interaction energy in such a system is lower compared to the other four polymorphs containing a bifurcated hydrogen bond, as evidenced by the positive values of the standard Gibbs free energy change (ΔG) at the three considered temperatures (298, 373, and 463 K). Extrapolation of the calculated ΔG values has shown that polymorph V can be obtained from polymorphs I, II, III, or IV exclusively by heating to the melting point (463 K) and then cooling to a temperature below 260 K