In this article, we define the notion of stable input-output negative imaginary (IONI) systems. This new class captures and unifies all the existing stable subclasses of negative imaginary (NI) ...systems and is capable of distinguishing between the strict subclasses (e.g., strongly strictly negative imaginary, output strictly negative imaginary (OSNI), input strictly negative imaginary, etc.) in the literature. In addition to a frequency-domain definition, the proposed IONI class has been characterized in a time-domain dissipative framework in terms of a new quadratic supply rate <inline-formula><tex-math notation="LaTeX">w(u,\bar{u},\dot{\bar{y}})</tex-math></inline-formula>. This supply rate consists of the system's input (<inline-formula><tex-math notation="LaTeX">u</tex-math></inline-formula>), an auxiliary input (<inline-formula><tex-math notation="LaTeX">\bar{u}</tex-math></inline-formula>) that is a filtered version of the system's input, and the time-derivative of an auxiliary output of the system (<inline-formula><tex-math notation="LaTeX">\dot{\bar{y}}</tex-math></inline-formula>). This supply rate corrects earlier supply rate attempts in the literature, which were only expressed in terms of the input (<inline-formula><tex-math notation="LaTeX">u</tex-math></inline-formula>) and the time-derivative of the system's output (<inline-formula><tex-math notation="LaTeX">\dot{y}</tex-math></inline-formula>). In this article, IONI systems are proved to be a class of dissipative systems with respect to the proposed supply rate <inline-formula><tex-math notation="LaTeX">w(u,\bar{u},\dot{\bar{y}})</tex-math></inline-formula>. Subsequently, an equivalent frequency-dependent <inline-formula><tex-math notation="LaTeX">(Q(\omega), S(\omega), R(\omega))</tex-math></inline-formula> dissipative supply rate is also proposed for IONI systems. These findings reveal the connections between the NI property and classical dissipativity in both the time domain and frequency domain. We also provide linear matrix inequality (LMI) tests on the state-space matrices to check whether a system belongs to the IONI class or any of its important subclasses. Finally, the derived results are specialized for OSNI systems since such systems exhibit interesting closed-loop stability properties when connected, in a positive feedback loop, to NI systems without poles at the origin. Several illustrative numerical examples are provided to make the results intuitive and useful.
Adsorpcija Zn(II) iona na metalurškom otpadu Anita Štrkalj; Luka Mesek; Vesna Ocelić Bulatović ...
Kemija u industriji; časopis kemičara i tehnologa Jugoslavije,
11/2022, Letnik:
71, Številka:
11-12
Journal Article
Recenzirano
Odprti dostop
Metalurški otpad ima velik potencijal za uporabu kao adsorbens za uklanjanje teških metala iz otpadnih voda, ističući se kao mogući jeftini adsorbens. U ovom članku prikazano je adsorpcijsko ...ponašanje Zn(II) iona na dva kruta metalna otpadna materijala – otpadnoj kalupnoj mješavini (OKM) i otpadnoj anodnoj prašini (AP). Dobiveni rezultati pokazali su da se oba otpadna materijala mogu upotrebljavati kao potencijalni adsorbensi. Anodna prašina ima bolja adsorpcijska svojstva. Ravnotežni podatci za adsorpciju Zn(II) na otpadnim metalurškim materijalima ispitani su Freundlichovim i Langmuirovim izotermnim modelima. Utvrđeno je da je Langmuirov model prikladniji te da se adsorpcija odvija kao kemisorpcija.
U ovoj studiji istraživana je adsorpcija Cu(II) iona na smjesi anatasa i rutila, dviju polimorfnih formi TiO2. Istražen je učinak vremena kontakta adsorbens/adsorbat i učinak početne koncentracije ...Cu(II) na adsorpciju. Rezultati su pokazali da ravnoteža nastupa već nakon jedne minute kontakta Cu(II) i TiO2 te da kapacitet adsorpcije raste s porastom početne koncentracije Cu(II) iona. Eksperimentalni podatci obrađeni su Langmuirovom i Freundlichovom izotermom. Dobiveni rezultati ukazuju da Freundlichov model bolje opisuje ispitivani adsorpcijski sustav te da je adsorpcija fizikalne prirode.
Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna .
In the last few years, various studies have been providing evidence that metal ions are critically involved in the pathogenesis of major neurological diseases (Alzheimer, Parkinson). Metal ion ...chelators have been suggested as potential therapies for diseases involving metal ion imbalance. Neurodegeneration is an excellent target for exploiting the metal chelator approach to therapeutics. In contrast to the direct chelation approach in metal ion overload disorders, in neurodegeneration the goal seems to be a better and subtle modulation of metal ion homeostasis, aimed at restoring ionic balance. Thus, moderate chelators able to coordinate deleterious metals without disturbing metal homeostasis are needed. To date, several chelating agents have been investigated for their potential to treat neurodegeneration, and a series of 8-hydroxyquinoline analogues showed the greatest potential for the treatment of neurodegenerative diseases.
Najnovija istraživanja na polju neurodegeneracije jasno pokazuju da kovinski ioni imaju značajnu ulogu u patogenezi Alzheimerove kao i drugih neurodegenerativnih bolesti. U skladu s ovim spoznajama upotreba kovinskih kelatora predstavlja zanimljiv i inovativan farmakološki pristup daljnjem istraživanju i mogućoj terapiji neurodegenerativnih stanja. U ovom radu ukratko je dan sažetak istraživanja upotrebe kovinskih kelatora u tretmanu Alzheimerove bolesti s posebnim osvrtom na istraživanja analoga 8-hidroksikinolina.
The size–age structure and growth of the Sardine Cisco
Coregonus sardinella
, the Siberian Whitefish
C. lavaretus pidschian
, and the Broad Whitefish
C. nasus
in Lake Ioni in eastern Chukotka has ...been studied for the first time. According to the results, the linear growth rate in whitefish decreases with age. The maximum body-length increase was recorded in the first year of life. The linear and weight growth data for the whitefish populations from Lake Ioni and the middle Anadyr River have been subjected to a comparative analysis.
The checklist of Tanaidacea of Greece was developed in the framework of the LifeWatchGreece Research Infrastructure (ESFRI) project and coordinated by the Hellenic Centre for Marine Research during ...the period 2013-2015. By applying the Greek Taxon Information System (GTIS) of this project, a complete checklist of species recorded from Greek Seas has been developed. The objectives of the present study were to update and cross-check all tanaidacean species known to occur in Greek Seas. Inaccuracies and omissions according to recent literature and the current taxonomic status were also investigated.
The up-to-date checklist of Tanaidacea of Greece comprises 20 species, classified to 11 genera and five families.