Magnetizing current of a Large Power Transformer and its Harmonic Spectrum in Normal and GIC conditions

A measurement of the harmonic spectrum of magnetizing current was performed. This paper analyzes the results of the measurement of harmonic spectrum of magnetizing current in standard noload test at various values of induction. Magnetizing current harmonic spectrum during single-phase noload test was measured as well as the impact of combined AC and DC magnetization on core behavior and harmonic spectrum. A mathematical model of transformer core is introduced. The calculated results are presented

Magnetizing current of a Large Power Transformer and its Harmonic Spectrum in Normal and GIC conditions

A measurement of the harmonic spectrum of magnetizing current was performed. This paper analyzes the results of the measurement of harmonic spectrum of magnetizing current in standard noload test at various values of induction. Magnetizing current harmonic spectrum during single-phase noload test was measured as well as the impact of combined AC and DC magnetization on core behavior and harmonic spectrum. A mathematical model of transformer core is introduced. The calculated results are presented

SKIN – EFFECT LOSSES IN DIFFERENT LOADING CONDITIONS OF A POWER TRANSFORMER

The subject of the analysis is a 300 MVA auto-connected power transformer in different loading conditions with regard to the load losses. During the electrical design time, some operating points of the transformer were analyzed in more detail using 2D electromagnetic field finite element method (FEM) software. The models included 2D magnetic stray field calculation and covered a range of transformer loading cases that covered some that are more difficult to solve with traditional analytic methods based on the static magnetic field calculations. This is due to the presence of a phase shift between the currents through the windings. The results of the static magnetic Rabins’ method field calculation and the FEM method are compared and the best practice method is defined and determined accordingly

Measurement of Circulating Currents in Split- Winding Transformer and Comparison with Numerical Calculation

Split-winding transformer is a one of the common transformer types with one low-voltage winding placed above the other low-voltage winding and with the jointly high-voltage and regulation winding. The paper investigates circulating currents that occur in high-voltage and regulation windings in case of nonsymmetric load. In addition, measurement of circulating currents for a case of 240MVA, 220 kV transformer is presented along with a numerical calculation of circulating currents and compared with the measurement

Measurement of Circulating Currents in Split- Winding Transformer and Comparison with Numerical Calculation

Split-winding transformer is a one of the common transformer types with one low-voltage winding placed above the other low-voltage winding and with the jointly high-voltage and regulation winding. The paper investigates circulating currents that occur in high-voltage and regulation windings in case of nonsymmetric load. In addition, measurement of circulating currents for a case of 240MVA, 220 kV transformer is presented along with a numerical calculation of circulating currents and compared with the measurement

Nicht pharmakologische Mittel für Neuroverbesserung. Neuroethische Fragen

Napredak u neuroznanosti i tehnologiji donio nam je nekoliko metoda s potencijalom nefarmakološkog utjecaja na mozak. Najveći broj tih metoda razvijen je sa svrhom tretiranja poremećaja, ali također imaju pogodne učinke na kogniciju i raspoloženje kod zdravih osoba, te potencijal za korištenje u svrhe poboljšavanja. Dvije kategorije metoda koriste se za tretiranje mozga; metode koje primjenjuju magnetsko polje i metode koje primjenjuju električno strujanje kroz skalp. Razvijeno je nekoliko metoda koje se služe jednim od tih principa, od kojih su najvaž- nije transkranijalna magnetska stimulacija (TmS) i transkranijalna stimulacija istosmjernom strujom (tDCS). Cilj ovog pregleda je dati kratak pregled različitih aspekata najšire korištenih nefarmakoloških tehnika koje mogu biti korištene u svrhe poboljšavanja te istaknuti najvažnije etičke probleme vezane za sigurnost, utjecaj na osobnost, pravdu te autonomiju upotrebe. Bez obzira na količinu informacija o mehanizmima i oblicima upotrebe metoda, mogući opseg i domet nuspojava i implikacija primjene nisu dovoljno naglašeni. Izvan kliničkih uvjeta uređaji nisu regulirani i ne postoji sustav osiguranja. Nadalje, sveprodiruća tehnologija koja okružuje naše življenje i manjak javnog dijaloga štete razvoju sporog i razumnog postupka implementacije i rezultiraju širenjem i komercijalizacijom njihove upotrebe.Advances in neuroscience and technology brought us several methods that have potential to non-pharmacologically influence our brain. most of these methods are developed with the purpose of treating disorders, but also have favourable results on cognition and mood in the healthy, and the potential to be used for enhancement purposes. Two categories of methods are used for treatments of the brain, methods that apply a magnetic field and those that apply an electrical current through the scalp. Several methods have been developed that use one of these principles for treatment, most important being transcranial magnetic stimulation (TmS) and transcranial direct current stimulation (tDCS). The aim of this review is to give a short overview of different aspects of the most widely used non-pharmacological techniques that can be used for enhancement purposes and state the most relevant ethical issues related to the safety, influence on character, justice and autonomy of their us. Irrespective of the amount of information on the mechanisms and modes of action for specific methods, the possible range and scope of their side effects and the implications of their potential use for enhancement, have not been emphasized enough. Outside clinical settings, these devices are unregulated, with no system in place to ensure their safety. moreover, the all-pervading technology that we live surrounded by and the lack of public discourse, all contribute against a reasonable and slow approach to their implementation and resulted in the spreading and increase in their commercial use.Les avancées technologiques et en neurosciences ont mis à jour de nombreuses méthodes ayant le potentiel d’avoir une influence sur notre cerveau sans avoir recours à des moyens pharmacologiques. Alors que la plupart de ces méthodes ont été développées dans le but de traiter les maladies, elles ont montré des résultats favorables concernant les capacité cognitives et émotionnelles chez des personnes en bonne santé, mais également du potentiel quant à l’amé- lioration de certaines caractéristiques non pathologiques. Deux catégories de méthodes sont utilisées pour les traitements sur le cerveau, celles qui se servent du champ magnétique et celles qui appliquent un courant électrique impulsé dans le crâne. Les quelques méthodes développées se servent d’un de ces principes pour le traitement des maladies, les plus importantes étant la stimulation magnétique transcrânienne (TmS) et la stimulation transcrânienne à courant direct (tDCS). Le but de cette recherche est de donner un bref aperçu des différents aspects des techniques non pharmacologiques les plus largement pratiquées qui peuvent être utilisées à des fins d’amélioration de caractéristiques non pathologiques, mais aussi de mettre en lumière les problèmes éthiques liés à la sécurité, à l’influence sur le caractère de la personne, à la justice et à l’autonomie de leur utilisation. Bien qu’une quantité d’informations sur les mécanismes et sur les modes d’action de ces méthodes spécifiques nous ait été fournie, l’étendue et la portée d’éventuels effets secondaires et les implications quant à leur potentiel utilisation pour l’amé- lioration de nos capacités n’ont pas encore été suffisamment soulignées. Ces dispositifs ne sont pas régulés en dehors du cadre clinique et aucun système n’a été mis en place pour assurer leur sécurité. De plus, la technologie omniprésente qui nous entoure et le manque de dialogue public vont à l’encontre d’une approche raisonnable et lente de leur mise en œuvre, ce qui a pour conséquence d’augmenter leur diffusion et leur utilisation à des fins commerciales.Die Fortschritte in der Neurowissenschaft und Technologie brachten uns mehrere methoden, die ein Potenzial zur nicht pharmakologischen Beeinflussung unseres Gehirns haben. Die mehrheit dieser methoden ist zum Zweck der Behandlung von Störungen entwickelt, darüber hinaus erzielen sie aber günstige Ergebnisse für die Kognition und Gemütsverfassung bei gesunden Personen und beinhalten das Potenzial für die Verwendung zum Verbesserungszweck. Zwei Kategorien von Verfahren werden zur Behandlung des Gehirns verwendet, methoden, die ein magnetisches Feld anwenden und jene, die elektrischen Strom durch die Kopfhaut einsetzen. Es wurden verschiedene methoden entwickelt, die eines dieser Prinzipien zur Behandlung verwenden, wovon sich die transkranielle magnetstimulation (TmS) und die transkranielle Gleichstromstimulation (tDCS) als bedeutendste erweisen. Die Intention dieses Überblicks ist es, ein kurzes Resümee der verschiedenen Aspekte der meistgebrauchten nicht pharmakologischen Techniken zu geben, die zum Verbesserungszweck verwendet werden können, und die relevantesten ethischen Fragen darzulegen, die in Zusammenhang mit Sicherheit, Einfluss auf den Charakter, Gerechtigkeit und Autonomie ihrer Verwendung stehen. Ungeachtet der menge an Informationen über die mechanismen und Handlungsweisen für bestimmte methoden wurden die mögliche Reichweite und der Umfang ihrer Nebenwirkungen und Implikationen bei deren potenziellen Verwendung zugunsten der Verbesserung ungenügend hervorgehoben. Außerhalb der klinischen Verhältnisse sind diese Geräte nicht reguliert und es besteht kein System an Ort und Stelle, um ihre Sicherheit zu gewährleisten. Die alldurchdringende Technologie, die unser Leben umgibt, und der mangel an öffentlichem Diskurs, beeinträchtigen zudem gemeinsam eine vernünftige und langsame Annäherung an ihre Implementierung und resultieren in der Ausbreitung und Zunahme ihrer kommerziellen Nutzung

The involvement of noradrenergic mechanisms in the suppressive effects of diazepam on the hypothalamicpituitary- adrenal axis activity in female rats

Aim To elucidate the involvement of noradrenergic system in the mechanism by which diazepam suppresses basal hypothalamic-pituitary-adrenal (HPA) axis activity. Methods Plasma corticosterone and adrenocorticotropic hormone (ACTH) levels were determined in female rats treated with diazepam alone, as well as with diazepam in combination with clonidine (α2-adrenoreceptor agonist), yohimbine (α2-adrenoreceptor antagonist), alpha-methylp- tyrosine (α-MPT, an inhibitor of catecholamine synthesis), or reserpine (a catecholamine depleting drug) and yohimbine. Results Diazepam administered in a dose of 2.0 mg/kg suppressed basal HPA axis activity, ie, decreased plasma corticosterone and ACTH levels. Pretreatment with clonidine or yohimbine failed to affect basal plasma corticosterone and ACTH concentrations, but abolished diazepaminduced inhibition of the HPA axis activity. Pretreatment with α-MPT, or with a combination of reserpine and yohimbine, increased plasma corticosterone and ACTH levels and prevented diazepam-induced inhibition of the HPA axis activity. Conclusion The results suggest that α2-adrenoreceptors activity, as well as intact presynaptic noradrenergic function, are required for the suppressive effect of diazepam on the HPA axis activity

„Predmeti opće uporabe svuda oko nas“

Laboratorij Odjela za predmete opće uporabe posjeduje dugogodišnju tradiciju od preko 50 godina u ispitivanju, ali i u istraživanju predmeta opće uporabe. Od svih zavoda za javno zdravstvo u RH u HZJZ je to samostalna jedinica koja se bavi isključivo predmetima opće uporabe. U predmete opće uporabe spadaju materijali i predmeti koji dolaze u neposredan dodir s hranom te predmeti široke potrošnje, posebice dječje igračke, kozmetika i deterdženti, što ukazuje na njihovu raširenost i izrazitu važnost u svakodnevnom životu. Stoga je vizija za budućnost unaprijediti metodiku rada u Odjelu i time prikupiti i obraditi što više podataka s ciljem unaprjeđivanja zdravstveno sigurnijeg načina života kroz zaštitu potrošača. U radu je dan kratki osvrt na djelatnost Odjela.

„Predmeti opće uporabe svuda oko nas“

Laboratorij Odjela za predmete opće uporabe posjeduje dugogodišnju tradiciju od preko 50 godina u ispitivanju, ali i u istraživanju predmeta opće uporabe. Od svih zavoda za javno zdravstvo u RH u HZJZ je to samostalna jedinica koja se bavi isključivo predmetima opće uporabe. U predmete opće uporabe spadaju materijali i predmeti koji dolaze u neposredan dodir s hranom te predmeti široke potrošnje, posebice dječje igračke, kozmetika i deterdženti, što ukazuje na njihovu raširenost i izrazitu važnost u svakodnevnom životu. Stoga je vizija za budućnost unaprijediti metodiku rada u Odjelu i time prikupiti i obraditi što više podataka s ciljem unaprjeđivanja zdravstveno sigurnijeg načina života kroz zaštitu potrošača. U radu je dan kratki osvrt na djelatnost Odjela.