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Resistance structure and solute removal pathways in UF–DF of sweet whey
Full text linkWhey is a high-volume by-product of dairy processing, rich in valuable proteins, lactose, and minerals, yet its utilization remains limited in many regions due to challenges related to shelf life, transport, and processing infrastructure. Membrane-based separations such as ultrafiltration (UF) and diafiltration (DF) offer chemical-free, low-energy routes for valorizing whey streams, but their efficiency depends not only on the nominal molecular weight cut-off (MWCO) of the membranes, but also on fouling dynamics and concentration polarization phenomena. In this study, sweet whey was subjected to UF combined with up to four constantvolume DF steps using polyethersulfone (PES) membranes with MWCOs of 10, 30, and 50 kDa. Retention of chemical oxygen demand (COD) and lactose was determined, and the evolution of total hydraulic resistance (RT) and its components – membrane resistance (RM), reversible resistance (RREV), and irreversible resistance (RIRR) – was evaluated. Results showed that COD retention closely followed lactose concentration changes, with strong correlations (r ≈ 0.99), confirming that small, permeable solutes dominated COD trends. UF exhibited clear MWCO-dependent retention (10 kDa > 30 kDa > 50 kDa), whereas during DF the sharpest decline occurred in the first diafiltration cycle (DF1), due to dilution-induced disruption of the concentration polarization layer and reduction of RREV. Beyond DF2, resistance stabilized and the separation performance of the 30 and 50 kDa membranes converged, indicating that hydrodynamic control outweighed nominal MWCO differences. For the 10 kDa membrane, irreversible fouling became more prominent in later DF steps, increasing RT. Overall, the first DF cycle resulted in the greatest removal of dissolved components with low molecular weight, while subsequent cycles contributed to a diminishing extent to the removal of these fractions, but further increased the purity of the protein fraction remaining in the retentate. These findings suggest that optimal industrial strategies should apply a limited number of DF steps and carefully consider fouling mechanisms to balance efficiency, product quality, and resource use
Development and evaluation of pear jam enriched with poppy seeds as a functional food product
Full text linkThis study aimed to develop an innovative functional food product — pear jam enriched with poppy seeds. Fruit jams are valuable sources of vitamins, minerals, simple sugars, soluble dietary fiber, phytonutrients, phytoestrogens, anti-inflammatory compounds, and antioxidants such as polyphenolic flavonoids, vitamin C, and anthocyanins. These bioactive compounds help neutralize free radicals, protecting the body against cancer, aging, and infections. Poppy seeds complement this profile, offering fats, proteins, manganese, calcium, linoleic acid, and vitamin E. Two types of jams — plain pear jam and pear jam with poppy seeds — were evaluated through sensory and physicochemical analyses. Sensory results showed that the poppy seed variant excelled in taste, appearance, and consistency, receiving the highest possible score (5.0), while color and aroma scored 4.8 points. Physicochemical analysis assessed sugar content, vitamin C concentration, and refractive index. Pear jam with poppy seeds exhibited higher sugar content (61.2°Brix) and refractive index (1.4501) than plain pear jam. However, vitamin C levels were slightly higher in plain pear jam (64.2 mg/100 g) compared to the enriched version (58.7 mg/100 g)
A pragmatikai annotáció kontextusfüggősége nagy nyelvi modell esetében - felszólító alakok funkcióinak annotálása huBert modellel
Full text linkTermészetes nyelvi szövegekben a pragmatikai jellemzők annotálása során nagy kontextust kell figyelembe venni. Tanulmányunkban azt vizsgáljuk, hogy egy pragmatikai jellemző automatikus annotálása során milyen hatással van a rendelkezésre álló kontextus nagyságának a változása. A vizsgálat egy olyan korpuszon történt, melyen rendelkezésre állt egy manuálisan rögzített pragmatikai annotáció a felszólító alakok funkcióinak kategorizálására. A korpusz segítségével a huBert base nagy nyelvi modellt finomhangoltuk az annotációs feladat elvégzésére, és megvizsgáltuk, hogy a modell az annotálás során milyen mértékben támaszkodik a rendelkezésre álló kontextusra. A kontextuális hatást kétféleképpen vizsgáltuk: a tanítószekvenciák hosszának változtatásával hogyan befolyásolja a modell összesített pontosságát; illetve az annotálandó elemek szekvencián belüli elhelyezkedése milyen hatással van az annotáció pontosságára
Existence and nonexistence of solutions for generalized quasilinear Kirchhoff-Schrödinger-Poisson system
Full text linkIn this paper, we consider the existence and nonexistence of solutions for a class of modified Schrödinger–Poisson system with Kirchhoff-type perturbation by use of variational methods. When nonlinear term h(u) = |u| p−2u, 1 ≤ p < ∞, the nonexistence of nontrivial solutions of system is demonstrated through Pohožaev identity. When nonlinear term h(u) satisfies appropriate assumptions, taking advantage of critical point theorem, we obtain a positive radial solution and a nontrivial one of system when g(u) satisfies different conditions. Moreover, some convergence properties are established as the parameter b → 0. What is more, the nonexistence of nontrivial solutions in critical case is also proved by use of Pohožaev identity
A kirakat mint "kiállító terem" - szabadkai fényképészek a szabadkai sajtóban, 1890-1919
Full text linkThe Szabadka (Subotica) press of the late 19th and early 20th centuries followed the work of local photographers with keen interest, and, at the same time, gave space in their columns to popularize them, thus providing valuable sources for the history of the trade of professional photographers of the era. The period when photography became established in the town can be dated back to the last decade of the 19th century when the number of photographers increased. In the period between 1890–1919, twelve names of photographers working in Szabadka appeared simultaneously in the local press. A significant proportion of occurrences drew attention to new or existing studios, reported on changes in locations, or told about opportunities to see finished products, and photographers presented the range of their services in advertisements. The paper deals with these topics and also touches on attitudes concerning issues of reception, as well as the perception of photography as a new medium of art, based on news reports, recountings, and advertisements in periodicals published in Szabadka
