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Computational Fluid Dynamics (CFD) Modelling of Annular Reactor for Photocatalytic Degradation of Air Pollutants Using COMSOL Multiphysics Software
No full textAn annular reactor is a type of reactor in which chemical reactants move through an annular gap between two concentric cylinders. This type of design is suitable for a variety of chemical processes because it facilitates efficient heat transfer and mixing of reactants. Previous research has shown that this type of reactor shows promising results in the photocatalytic decomposition of pollutants, which is why it is used in air purification tests. This paper presents a model of one such type of air purification reactor modeled in COMSOL Multiphysics simulation software and provides an overview of the steps that need to be taken in order to effectively model the photocatalytic oxidation. The purpose of modelling the reactor is to test its effectiveness in computer simulations of the decomposition of pollutants in the air using the process of photocatalytic oxidation, which is a combination of photooxidation based on the effect of UV radiation and catalytic oxidation. The resulting simulations allow the scaling of the system (its increase or decrease) so that it can be adapted to certain conditions and used in the real world as a method of air purification at the very sources of polluted air
Effects of radiofrequency electromagnetic radiation with a focus on haematology parameters: a brief review and future research needs
No full textOd 1950-ih godina primjena radiofrekvencijskog elektromagnetskog zračenja (RF-EMZ) u stalnom je porastu. RF-EMZ se koristi u: medicini, industriji, kućanskim uređajima, sigurnosti i navigaciji, a posebno u bežičnoj telekomunikaciji, stočarstvu. Raširena uporaba RF-EMZ-a, posebice uvođenjem 5G mreže, prouzroči zabrinutost
javnosti o mogućim štetnim učincima na ljudsko i životinjsko zdravlje. Učinci i mehanizmi djelovanja RF-EMZ na ljudsko i životinjsko zdravlje frekvencijskog pojasa iz 5G mreže do sada su gotovo nepoznati ili ako jesu vrlo oskudno istraženi. Dosadašnja istraživanja uključuju: biološki učinak RF-EMZ-a na genotoksičnost, staničnu
proliferaciju, ekspresiju gena, staničnu signalizaciju, funkciju staničnih membrana te na funkciju imunosnog, hematopoetskog i reproduktivnog sustava. Dokazano je da izloženost ljudi i pokusnih životinja RF-EMZ-a koje su emitirali mobilni telefoni i drugi elektronički uređaji 4G i starije tehnologije uzrokuju štetne učinke na krvne stanice i promjenu kompletne krvne slike. Navedeno ovisi o vrsti izloženih živih bića, izvorima RF-EMZ-a,
frekvenciji, učestalosti i trajanju izloženosti. U dostupnoj su literaturi podatci o učinku RF-EMZ-a na hematološke pokazatelje i morfometriju eritrocita domaćih životinja vrlo su oskudni. Stoga je cilj ovog preglednog znanstvenog rada prikazati učinak RF-EMZ na hematološke pokazatelje, morfometriju eritrocita i aktivaciju trombocita u ljudi i životinja s osvrtom na saznanja o učincima 5G elektromagnetskog zračenja na prethodno navedene pokazatelje. S obzirom na sveprisutno elektromagnetsko onečišćenje važno je steći saznanja o učinku RF-EMZ-a na zdravlje ljudi i životinja. Osim toga, potrebno je utvrditi i učinke nakon in vitro izlaganja krvi RF-EMZ-u zbog pohrane te primjene krvi i krvnih pripravaka u transfuzijiskoj medicini.The use of radiofrequency electromagnetic radiation (RF-EMR) has steadily increased since the 1950s. RF-EMR is used in medicine, industry, household appliances, security and navigation, and especially in wireless elecommunications and animal husbandry. The widespread use of RF-EMR, especially with the introduction of 5G networks, raises concerns about potential adverse effects on human and animal health. The effects and mechanisms of RF-EMR impacts of 5G network frequencies on human and animal health are still unknown or
poorly understood. Current research findings include the biological effects of RF-EMR on genotoxicity, cell proliferation, gene expression, cell signalling, cell membrane function, and the function of immune, ematopoietic, and reproductive systems. Exposure of humans and laboratory animals to RF-EMR emitted from cell phones and many other electronic devices of 4G and older technologies has been shown to have detrimental effects on blood cells and to cause changes in the complete blood count. This depends on the type of organisms exposed, sources,
frequency, electric field level and duration of exposure. There is sparse data in the available literature on the effects of RF-EMR on haematology indicators and erythrocyte morphometry in domestic animals. Therefore, the aim of this scientific review is to highlight the effects of RF-EMR on haematology indicators, erythrocyte morphometry, and platelet activation in humans and animals, taking into account the findings on the effects of 5G electromagnetic radiation on these indicators. Considering the ubiquitous electromagnetic pollution, it is important to gain knowledge about the effects of RF-EMR on human and animal health. In addition, it is necessary to determine the effects following in vitro exposure of blood to RF-EMR, especially due to the storage and use of blood and blood products in transfusion medicine
The current state of Alex’s line in the Bohemian Shepherd Dog breed
No full textOvčarski pas iz Bohemije je češka radna pasmina pasa, srednje veličine, s crnom dugom dlakom, paležom i s karakterističim oblikom uške. Psi ove pasmine su umiljati, lako se obučavaju i bez znakova nervoze. Ova stara pasmina, poznata od 13. stoljeća, gotovo je nastala stoga su 1984., Jan Findejs i Dr. Vilém Kurz pokrenuli regeneraciju pasmine. Jedan je od parnjaka korišten u tom projektu bio i pas imenom Alex. Cilj je istraživanja bio
otkriti stanje Alexove linije (IV. linije) i broj pasa potomaka oštenjenih od 2021. do kraja prvog kvartala 2024. Alex je korišten 13 godina nakon početka oživljavanja pasmine, a samo sa dva potomka prve generacije koji su se koristili u uzgoju, Alexova je linija činila 2,7 % ukupne populacije od 1996. do 2008. Godine 2009. počela je ekspanzija korištenjem triju mužjaka koji su svaki imali po više od 100 štenaca. Zbog toga je Alexovo potomstvo činilo 41,25 % svih registriranih štenaca od 2021. do 2024., stoga je genetsko testiranje prije parenja nezamjenjiva mjera prevencije genetskih bolesti u čistokrvnih pasa.The Bohemian Shepherd Dog is a Czech working dog breed of medium size with a long black and tan coat and characteristic ear shape. The dogs of this breed are friendly, trainable, and with no sign of nervousness. The population of this historic breed of dogs, known since the 13th century, was almost destroyed until 1984, when Jan Findejs and Dr. Vilém Kurz partnered to take the first steps to regenerate the breed. One of the sires used in the project was a sire named Alex. This study aimed to determine the state of Alex’s line (IV. line), and the number of descendant dogs born from 2021 until the first quarter of 2024. Used 13 years after the start of the breed regeneration project, and with only two breeding first-generation descendants, Alex’s line accounted for 2.7% of the population from the beginning in 1996 until 2008. In 2009 an expansion started, caused by three of his male descendants who sired more than 100 puppies each, resulting in Alex’s progeny accounting for 41.25% of all registered puppies from 2021 to 2024. Therefore, genetic testing before mating is now an essential measure to prevent genetic diseases in purebred dogs
Treatment of the Patient with Brugada Syndrome – a Case Report
No full textCilj: Brugadin sindrom predstavlja rijedak genetski poremećaj koji se može prepoznati po karakterističnim promjenama EKG zapisa. Sindrom je češći u zemljama jugoistočne Azije u odnosu na ostatak svijeta. S obzirom na sve veću prisutnost stranih radnika iz područja jugoistočne Azije u Europi, cilj je ovoga rada skrenuti pozornost zdravstvenih djelatnika na sindrom i educirati ih radi ranog prepoznavanja i pravovremene stratifikacije rizičnih bolesnika. Prikaz slučaja: Ovim radom prikazuje se slučaj bolesnika hospitaliziranog zbog izvanbolničkog srčanog zastoja. Nakon hemodinamske stabilizacije na hitnom prijamu učinjen je EKG kojim su uočene promjene indikativne za Brugadin obrazac tipa 1. Tijekom obrade ubrzo je ponovno došlo do srčanog aresta uslijed polimorfne ventrikularne tahikardije. Ovoga puta, usprkos brojnim defibrilacijama i terapiji, inicijalno nije postignut povratak spontane cirkulacije. Električna oluja okončana je tek primjenom izoproterenola, agonista β-adrenoreceptora preporučenog smjernicama Europskog kardiološkog društva u slučaju električne oluje u bolesnika s Brugadinim sindromom. U daljnjem tijeku prikaza opisuje se boravak u bolnici i liječenje bolesnika, razvoj komplikacija, njihovo zbrinjavanje i implantacija kardioverter-defibrilatora u sekundarnoj prevenciji. Zaključak: Specifičnost ovog sindroma je povećan rizik iznenadne srčane smrti u zdravih i relativno mladih ljudi, većinom muškaraca. Smjernice daju jasne preporuke o zbrinjavanju simptomatskih bolesnika, kao i onih s Brugadinim obrascem tipa 1. Za obrasce tipa 2 i 3 nisu dane jasne smjernice, stoga za stratifikaciju rizika i daljnje postupanje može poslužiti konsenzus eksperata izražen u Šangajskom bodovnom sustavu. Od velike je važnosti prepoznati EKG zapise s Brugadinim obrascem te pravovremeno uputiti bolesnika na daljnju obradu u cilju primarne prevencije iznenadne srčane smrti.Aim: Brugada syndrome is a rare genetic disorder that can be recognized by characteristic changes in ECG records. The syndrome is more common in Southeast Asian countries than in the rest of the world. Considering the increasing presence of foreign workers from Southeast Asia in Europe, this work aims to draw attention of healthcare professionals and educate them on early recognition and prompt stratification of patients at risk. Case report: This paper presents the case of a patient hospitalized due to out-of-hospital cardiac arrest. After hemodynamic stabilization at the emergency department, ECG showed changes indicative of Brugada pattern type 1. Cardiac arrest soon occurred again due to polymorphic ventricular tachycardia. This time, despite numerous defibrillations and therapy, the return of spontaneous circulation was not achieved initially. The electrical storm was finally terminated by the administration of isoproterenol, a β-adrenoreceptor agonist recommended by the Guidelines of the European Society of Cardiology. In the further course, the hospital stay, development of complications, their treatment, and the implantation of a cardioverter defibrillator in secondary prevention are described. Conclusion: The specificity of this syndrome is the increased risk of sudden cardiac death in healthy and young individuals, mostly men. The Guidelines give clear recommendations on the management of symptomatic patients, as well as those with Brugada pattern type 1. No clear guidelines are given for pattern types 2 and 3. Therefore, the consensus of experts expressed in the Shanghai scoring system can be used for risk stratification and further treatment. It is of great importance to recognize ECG records with the Brugada pattern and to promptly refer the patient for further evaluation with the aim of primary prevention of sudden cardiac death
Hidrogenaze – tipovi, izvori, svojstva i potencijalnjihoveprimjene
No full textHydrogenases are a group of versatile metalloenzymes that catalyse the reversible transformation between hydrogen gas and its constituent protons and electrons. These enzymes have gained attention more recently due to their ability to use molecular hydrogen as a substrate in the reactions they catalyse, as well as their potential to synthesise hydrogen, an important biofuel. Although the existence of hydrogenases has been known since the 1930s, current research has not yet made them viable on the industrial scale. They are explored mostly from the biochemical point of view, which is very important, but there is a lack of research on how to adapt these enzymes for real industrial-scale processes. Only a few studies address this gap. Therefore, in this brief literature review, we provide an overview of what is known about hydrogenases. We explore their background, classification, and phylogeny, highlighting their presence in many different sources in nature, such as bacteria, archaea, and certain eukaryotes. We also discuss key factors influencing their activity, along with their advantages and disadvantages. Furthermore, we summarise the methods available for determining their activity and emphasise the need for standardised units to ensure comparability of all data available in the literature. Finally, we discuss their potential applications, particularly in hydrogen production and synthetic reaction pathways for coenzyme regeneration, emphasizing the critical importance of these aspects in the investigation of hydrogenases.Hidrogenaze su skupina svestranih metaloenzima koji kataliziraju reverzibilnu transformaciju između plinovitog vodika i njegovih sastavnih protona i elektrona. Ti su enzimi nedavno privukli pažnju zbog svoje sposobnosti primjene molekularnog vodika kao supstrata u reakcijama koje kataliziraju, kao i sposobnosti sintetiziranja vodika, danas vrlo važnog biogoriva. Iako je poznato da hidrogenaze postoje još od 1930-ih, dosadašnja istraživanja nisu dovoljna za njihovu primjenu na industrijskoj razini. Istražuju se uglavnom s biokemijskog gledišta, što je vrlo važno, ali nedostaju istraživanja koja bi te enzime učinila primjenjivijima u stvarnim industrijskim procesima. Postoji samo nekoliko studija u tom području. Stoga ovdje predstavljamo kratak pregled literature o onome što je poznato o hidrogenazama. Pokušali smo objasniti njihovu pozadinu, klasifikaciju i filogeniju, budući da se mogu pronaći u mnogim različitim izvorima, poput bakterija, arheja i u nekim eukariotima. Pobrojali smo važne čimbenike koji utječu na njihovu aktivnost te dali naglasak na njihovim prednostima i nedostacima. Uz to, predstavili smo dostupne metode za određivanje njihove aktivnosti i naglasili važnost postojanja jedinstvenih jedinica za njihovo izražavanje, jer je trenutačno teško usporediti sve dostupne podatke. Na kraju smo dali prikaz njihove potencijalne primjene kao ključne teme u istraživanjima, a to je u proizvodnji vodika te u sintetskim reakcijskim putevima za regeneraciju koenzima
Korelacija vaginalne citologije i razine progesterona tijekom nadziranja ciklusa estrusa u kuja
No full textThis study investigated the relationship between vaginal cytological examination and progesterone levels (P4) during a 12.5-month period of cycle monitoring in 16 domestic bitches subjected to oestrus induction treatments. By analysing the correlations between P4 rates and cellular parameters (specifically eosinophilia and basophilia percentage), the study aimed to establish a reliable cellular parameter that can serve as an indicator of low progesterone thresholds. Preliminary monitoring was conducted through bi-weekly visits. At each visit, all animals systematically underwent a vaginal smear stained with the Harris-Schorr trichrome method. For P4 assess-ment, plasma samples were analysed using a radioimmunoassay method. Cycle control during and after oestrus induction was accompanied by clinical, cytological and hormonal monitoring until the gestational state was confirmed. Chi-square test was applied to study the correlation in a population consisting of 282 smear slides corresponding to the corre- sponding P4 values. Data showed that at the beginning of proestrus, P4 levels were highly significantly correlated with the percentages of basophilic and eosinophilic cells. Among the cytological criteria evaluated for both cellular percentages, having more than 40% basophilic cells on the vaginal smear proved to be the most reliable with a zero margin of error. Its application indicated that when the percentage of basophilic cells is strictly greater than 40%, P4 values are below 2 ng/mL, and once the percentage of basophilia falls below 40%, the P4 assays become valuable. Thus, in the context of cycle monitoring, this cellular indicator could be particularly useful in avoiding costly and unnecessary progesterone measurements and reducing their frequency at the beginning of proestrus.Ova studija istražila je odnos između pregleda vaginalne citologije (VCE) i razina progesterona (P4) tijekom razdoblja od dvanaest i pol mjeseci nadziranja ciklusa u šesnaest domaćih kuja podvrgnutih tretmanima indukcije estrusa. Analizirajući korelaciju između P4 stopa i celularnih parametara (posebno postotka eozinofila i bazofila), ovaj rad imao je za cilj utvrditi pouzdani celularni parametar koji može poslužiti kao indikator niskih pragova progesterona. Preliminarni nadzor 16 kuja proveden je putem dvotjednih posjeta. Kod svake posjete, sve životinje su sistematski podvrgavane vaginalnom brisu i Harris-Schorr trikrom metodi za naknadno bojanje stakalca. Za P4 procjenu, uzorci (plazma) su analizirani uporabom metode radioimunotesta. Kontrola ciklusa tijekom i nakon tretiranja indukcije estrusa popraćena je kliničkom, citološkom i hormonalnom nadzoru dok nije potvrđena gestacija. Primijenjen je Hi-kvadrat test za istraživanje korelacija u populaciji koja se sastojala od 282 stakalca briseva koji su odgovarali 282 P4 vrijednosti. Podatci su pokazali da su na početku proestrusa, P4 razine bile vrlo značajno korelirane (P 40 % bazofila) dokazano je kao najpouzdanije s nultom marginom greške. Njegova primjena pokazala je da kada je postotak bazofilnih stanica bio strogo veći od 40 %, P4 vrijednosti su ispod 2 ng/mL (što znači da je P4 mjerenje nepotrebno), a kada ovaj postotak bazofila padne ispod 40 %, P4 testovi postaju vrijedni. Stoga, u kontekstu praćenja ciklusa, ovaj celularni indikator mogao bi biti posebno koristan za izbjegavanje skupih i nepotrebnim mjerenja progesterona i smanjenje njihove učestalosti na početku proestrusa
Selection method for interpretability logic IL with respect to Verbrugge semantics
No full textInterpretability logic is a modal logic which formalizes the notion of relative interpretability between first-order arithmetical theories. Veltman semantics is the basic semantics for interpretability logic. Verbrugge semantics is a generalization of Veltman semantics. Selection is one of the methods to establish finite model property of a logical system, as a step towards showing that the system is decidable. In this paper we show that selection method can be applied to Verbrugge models, by adapting techniques used for Kripke models to this more complex setting
A generalization of a theorem of Murat Alan
No full textLet (Fn)n≥0 and (Ln)n≥0 be the Fibonacci and Lucas sequences respectively. In 2022, Murat Alan found all Fibonacci and Lucas numbers which are concatenations of two terms of the other sequence. Let b ≥ 2 be an integer. In this paper, we generalize the results of Murat Alan by considering the following Diophantine equations Fn = bdLm + Lk and Ln = bdFm + Fk in non-negative integers (n, m, k), where d denotes the number of digits of Lk and Fk in base b, respectively
β-expansion of p-adic numbers with Pisot-Chabauty bases
No full textThe aim of this paper is to study some arithmetic properties about the finiteness and the periodicity of the β-expansion of p-adic numbers. We prove that if the β-expansion of unity or rationals verifies some conditions then β is a Pisot-Chabauty number
Conics in cubic structure
No full textBy using ternary relation, in this paper we introduce the concept of a conic in a general cubic structure, and study the properties of the conics in cubic structures of ranks 1, 2, and 3. By means of points of a conic, we construct different configurations of points and conics, lines and conics, as well as some well-known configurations of points and lines