343 research outputs found
Mechanism of a Solid-State Formation of La1-xSrxMnO3+δ (0 \u3c x \u3c 0.5) and Magnetic Characterization Thereof
Rich diversity of potential, substantially different micro-structural arrangements - reflecting on the wide potential set of interesting properties, ranging from high electrical conductivity to giant, collossal and/or low-field magnetoresistance to low Curie point - of LaSr-manganite materials opens possibilities for numerous scientific investigations oriented towards revealing correlations on the influence line: procedure of synthesis → inherent properties → measured properties → application of the material. The investigations of the influence of synthesis procedures and LaSr-manganite stoichiometries on the Curie point (and other magnetic characteristics) of the material, being the topic of this work, are attractive since they present a necessary primal step in the development of nano-magnetic drug carriers based on these materials. In the course of such an investigation, the mechanism of the formation of the desired manganite compounds by following a classical solid-state preparation method, was also studied
Electronic Structure of Hydrazinium (2 + ) Ion. A Semiempirical MO Treatment
A simple semiempjrical MO treatment of the electronic structure
of hydrazinium (2 + ) ion was carried out on the basis of an
extended Htickel method. The electronic population analysis for
nitrogen and hydrogen atoms in this ion was calculated to b e (ls) 2
(2s)1 -121 (2px)1 ·3Go (2py)t·3Go (2p z)o .9BG and (ls)0o122, respectively
The Characterization of Nanosized Nickel-Zinc Ferrites Synthesized within Reverse Micelles of CTAB/1-Hexanol/Water Microemulsion
Stoichiometric nanocrystalline nickel–zinc ferrites were synthesized by a reverse micelle method following a multi-microemulsion approach. Different pH values were chosen for the alkali precipitating reaction during the synthesis of different powders. Synthesized, as-dried and subsequently calcined powders were characterized in terms of their magnetic properties. XRD analyses and specific-surface area measurements were used to determine the average particle sizes of the synthesized samples. DCS and TGA measurements were performed to reveal the phase transitions within the samples at elevated temperatures, whereas TEM was used to view and record the microstructure of the nanosized ferrite samples. A possible mechanism of the formation of the synthesized NiZn-ferrite was also discussed
Synthesis of Lanthanum-Strontium Magnanites by a Hydroxide-Precursor Co-Precipitation Method in Solution and in Reverse Micellar Microemulsion
Nanostructured lanthanum-strontium manganites have been synthesized using two different co-precipitation approaches, one in bulk solution, and the other in reverse micelles of CTAB/1-hexanol/1-butanol/water microemulsion. In both cases, precursor cations were precipitated by alkali precipitating agents. The properties of the material synthesized by using these two methods were compared in order to reveal potential advantages of microemulsion-assisted approach. The influence of the annealing conditions on the properties of synthesized manganites was investigated by using X-ray diffraction, transmission electron microscopy, differential thermal analysis, thermogravimetric analysis and magnetic measurements
Kemični povzročitelji hormonskih motenj - strategija Evropske unije in stališče Slovenije
In view of the European Union regulations 1107/2009 and 528/2012, which say that basic substances in plant protection and biocidal products marketed in the European Union (EU) should not have an inherent capacity to cause endocrine disruption, an initiative was started to define scientific criteria for the identification of endocrine disruptors (EDs). The objectives of the EU strategy on EDs are to protect human health and the environment, to assure the functioning of the market, and to provide clear and coherent criteria for the identification of EDs that could have broad application in the EU legislation. Policy issues were to be addressed by the Ad-hoc group of Commission Services, EU Agencies and Member States established in 2010, whereas the scientific issues were to be addressed by the Endocrine Disruptors Expert Advisory Group (ED EAG), established in 2011. The ED EAG adopted the 2002 World Health Organization (WHO) definition of endocrine disruptor and agreed that for its identification it is necessary to produce convincing evidence of a biologically plausible causal link between an adverse effect and endocrine disrupting mode of action. In 2014, the European Commission proposed four ED identification criteria options and three regulatory options, which are now being assessed for socioeconomic, environmental, and health impact. Slovenia supports the establishing of identification criteria and favours option 4, according to which ED identification should be based on the WHO definition with the addition of potency as an element of hazard characterisation. As for regulatory options, Slovenia favours the risk-based rather than hazard-based regulation.Uredbi Evropske unije 1107/2009 in 528/2012 navajata, da osnovne snovi fitofarmacevtskih in biocidnih sredstev odobrene za uporabo v Evropski uniji (EU), same po sebi ne povzročajo hormonskih motenj. Zato je potrebno definirati znanstvene kriterije za identifikacijo kemičnih povzročiteljev hormonskih motenj (KPHM). Cilji strategije EU na področju KPHM so varovanje zdravja ljudi in okolja, zagotavljanje delovanja trga ter jasnih in skladnih kriterijev za identifikacijo KPHM, ki bodo omogočali široko uporabo teh kriterijev v zakonodaji. Za obravnavo politik je bila leta 2010 ustanovljena Ad-hoc skupina predstavnikov Evropske komisije, EU agencij in držav članic; leta 2011 pa še ekspertna svetovalna skupina (ESS), ki je obravnavala znanstvene vidike. ESS je privzela definicijo KPHM Svetovne zdravstvene organizacije (SZO) iz leta 2002. Člani ESS so soglašali, da so za identifikacijo KPHM potrebni prepričljivi dokazi biološko verjetne vzročne povezave med škodljivim učinkom in hormonskim načinom delovanja. Evropska komisija je 2014 predlagala 4 možnosti kriterijev za identifikacijo KPHM in 3 možnosti obravnave. Začela se je tudi poglobljena ocena socio-ekonomskih, okoljskih in zdravstvenih vplivov predlaganih možnosti. Slovenija podpira uvedbo 4. možnosti, v skladu s katero kriteriji za identifikacijo KPHM temeljijo na definiciji SZO ob upoštevanju moči kot elementa karakterizacije nevarnosti. Slovenija daje prednost nadzoru, ki temelji na oceni tveganja in ne zgolj na oceni nevarnosti
Preparation of Silica-Coated Lanthanum-Strontium Manganite Particles with Designable Curie Point, for Application in Hyperthermia Treatments
Silica-coated lanthanum–strontium manganite particles with La0.76Sr0.24MnO3+δ stoichiometric formula, exhibiting Curie temperature at ∼40°C, were prepared by using a traditional solid-state method of synthesis of magnetic ceramic particles, followed by milling and a low-temperature coating procedure in an aqueous alcoholic alkali medium. The properties of the obtained material establish it as a potential candidate for self-regulated power-absorbing and temperature-controlling materials in hyperthermia treatments. Moreover, core-comprising LaSr–manganites with different stoichiometries, ranging from La0.5Sr0.5MnO3+δ to LaMnO3+δ, were synthesized, with magnetic and structural properties examined thereof. Herein reported findings can potentially be used in the preparation of silica-coated magnetic particles with designable Curie temperature, offering a wide range of possibilities of adapting the material to practical instrumental setups in drug delivery and hyperthermia treatments
Thermodynamic Aspects of Homeopathy
The well-known definition of disease, which Samuel Hahnemann presented in a tentative theory for his new science and art of healing, is used as the starting point for the thermodynamic model of homeopathy. The Le Chatelier principle was applied to the biochemical equilibrium compartmentalized in the individual human cells of an ill person to explain the curing based on the re-establishment of the starting equilibrium of a healthy person when using a remedy. It is revealed that a high dilution accompanied by succession is required to release the remedies to their constituent molecular species in order to increase their activity when taking part in the biochemical equilibrium that is essential for healing. In addition, a single remedy reaction-product species, when it is in excess, as well as satisfying the kinetic equilibrium, is a necessary and sufficient condition to force the new biochemical equilibrium in the direction of the basic original equilibrium associated with a healthy state. In addition, homeopathic aggravation is considered on the basis of the Law of Mass Action and the role of the small remedy concentration in some high-profile models is revisited. The second elementary law of homeopathy, the Law of the Infinitesimals, was explained based on a kinetic model. When a remedy occurs in the human cell of a healthy person and forms a reaction product (Simillimum) that induces the finest medical symptoms of an ill person, then remedies entering the cell of the ill person will form identical Simillimum molecules and re-establish the initial equilibrium of the healthy state and cure the ill person. However, this will also induce a molecular crowding in the cells of the ill person. For kinetic reasons, this will aggravate the re-establishment of the initial equilibrium and consequently worsen or even interrupt the medical treatment. At a low remedy concentration, the molecular crowding becomes negligible while the formation of the Simillimum and the re-establishment of the initial equilibrium will take place continuously and cure the person who is ill. The final understanding of the Simillimum in the thermodynamic model was illuminated and wide-opened its duality with the ill person’s key compound
Splošno, neformalno izobraževanje za razvoj civilne družbe
The paper deals with the status and development options of general informal education. The discussion is based on the role that this kind of education had in Scandinavian countries, and on the definition of general informal education as an activity that stems from personal human needs, rather than from an individual's occupational or social role. This also characterises the learning process in general informal education, which distinguishes this kind of education from learning and education in the formal or informal occupational education. It is precisely due to the autonomy in determining the educational objectives and due to the manner of learning characteristic of general informal education, that makes this kind of education a "school" for the development of civil society and is closely tied with the development of democracy and information society. The article first presents the position of general informal education in the documents of international organisations and its position in the long- and mid-term development plans of education or lifelong learning in several EU Member States. Then the article discusses the position and role of general informal education in selected Slovenian development documents on the one hand and its actual status on the other hand, and makes several international comparisons. The final section the article presents the position of general informal education in the basic professional documents for the national programme of adult education and the prospects and dilemmas of this type of education.Prispevek obravnava položaj in razvojne možnosti splošnega neformalnega izobraževanja. Obravnava temelji na vlogi, ki jo je imelo tovrstno izobraževanje v skandinavskih državah, in na opredelitvi pomena splošnega neformalnega izobraževanja kot dejavnosti, ki izhaja iz človekovih osebnih potreb in ni povezana z njegovo poklicno ali družbeno vlogo. Od tod tudi značilnosti učenja v splošnem neformalnem izobraževanju, po katerem se tovrstno učenje razlikuje od učenja in izobraževanja v formalnem ali neformalnem poklicnem izobraževanju
Residental real estate transactions in the time of recession
The intention of the thesis was, to look for reasons and consequences of the real estate markets condition in the time of recession. At first the Slovenian apartment market was analyzed for the period of 2007 to 2013. Analytical areas of Celje, Koper, Kranj, Ljubljana, Maribor, Murska Sobota and Novo mesto were analyzed for data including number of apartment units sold and their average price [€/m2]. Furthermore the number of economically active residents, migration, net wages, registered unemployment, number of building permits issued, total area of newly built apartment buildings and apartment types were analyzed for chosen municipalities. Lastly a short anonymous survey was answered by representatives of larger real estate agencies that work in the analytic areas. Their answers help us with understanding the functioning of the real estate market. All the things considered we come to a conclusion that the price and sales drop of the apartments was mostly due to the rise of registered unemployment. The consequences of the recession were projected on the number of newly built apartment buildings, there was drastically less of them build after the crisis begun. We can notice the rise of rentable apartments on the market, that is due to the housing loans that were harder to get approved for the general population
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