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Intenzivnost vpadne sončne svetlobe in temperatura sončnih celic imata velik vpliv na izhodno napetost. Tako se izhodna napetost sončnih celic spreminja predvsem v odvisnosti od osvetlitve, ob tem pa obstaja kompleksna povezava med sončnim vzbujanjem, temperaturo in totalno upornostjo polprevodniških celic. Iz omenjenega razloga imajo sončne celice nelinearen potek izhodnega izkoristka. S sledenjem točke največje izhodne moči na karakteristiki sočnih celic lahko zagotovimo optimalno izrabo pretvorjene sončne energije. V polnilnih sistemih je lahko izhodna napetost sočnih celic posledično prenizka za izvajanje polnilnega cikla, kar vključuje potrebo po dodatnem reguliranem pretvorniku enosmernih napetosti. Predmet raziskovanja v okviru predlaganega diplomskega dela je preučiti delovanje sončnih celic in razvoj polnilnega regulatorja za samodejno optimalno polnjenje akumulatorjev pri različnih pogojih sončne aktivnosti. The intensity of the entering sun light and the temperature of solar cells have a great impact on the cell output voltage. Thus the output voltage of solar cells change primarily because of different lighting conditions, where there is a complex connection between the Sun arousal, the temperature and the total resistance of solar cells. For the reason mentioned before, the solar cells have a non linear function of efficiency. By tracking the point of the highest output power on the output characteristic of the solar cells, we can ensure the optimal use of the transformed Sun energy. In the charging systems, the output voltage of the solar cells can be consequently too low to perform the charge cycle in which case there is a need for an additional regulating transformer of DC voltages. The main goal of this diploma paper is to investigate the activity of the solar cells and the development of the charging regulator for automatic optimum charging of batteries under different conditions of the Sun activity.

Izhodišča: V diplomskem delu smo izpostavili stres, ki je neizogiben del življenja v nujni medicinski pomoči. Reševalci v nujni medicinski pomoči se dnevno srečujejo z različnimi obremenjujočimi situacijami, ki lahko vplivajo na počutje, delovanje organizma, psihično ravnovesje, imunost in zdravje posameznika. Z raziskavo smo ugotavljali, v kolikšni meri so reševalci v službi nujne medicinske pomoči pri svojem delu izpostavljeni stresnim situacijam in obremenitvam kot so: neučakani pacienti, prevelike zahteve nadrejenih, slabe delovne razmere, strah pred tem, da bi napravili strokovno napako ter slabe možnosti napredovanja. V empiričnem delu je uporabljena kvantitativna metodologija raziskovanja, s pomočjo katere smo ocenjevali vpliv stresa na delo in zdravje reševalcev. Dobljene podatke smo statistično obdelali s programom Microsoft Office ter jih ponazorili z grafi. Rezultati: Ugotovili smo, da se reševalci v nujni medicinski pomoči pogosto srečujejo s stresom na delovnem mestu. Ugotovili smo tudi, da večina anketiranih nima strokovne pomoči s strani zavoda, v katerih so zaposleni. Sklepi: Prepoznavanje, obvladovanje in omejevanje negativnih vplivov stresa nedvomno pripomore k dvigu odpornosti na stresa dogajanja. Le tako bomo samozavestni, zadovoljni, majn obremenjeni in predani svojemu delu. Background: In this thesis we highlighted stress. Stress is an inevitable part of life in the emergency medical service. Paramedics in the emergency medical service are daily confronted with difficult situations that may affect the well-being and functioning of the organism, psychological balance, immunity and health of the individual. The survey was used to determine the extent to which paramedics in emergency medical service are exposed to stressful situations and stress such as: the inpatient patient, excessive demands of superiors, poor working conditions, fear of professional misconduct and poor promotion prospects. Quantitative research method was used in the empirical part of this work. We assessed the effect of stress on work and health of paramedics. Obtained data was statistically analyzed using Microsoft Office programs and illustrated with graphs. Results: We established that the paramedics in the emergency medical service are often faced with stress in the workplace. Results also showed that most respondents in the survey do not have technical support from the institution where they work. Conclusions: Identification, control and limitation of negative effects of stress undoubtedly contributes to a better resistance to stressful situations. Only like that we will be confident, happy, less burned-out and dedicated to our work.

Lovastatin is a cholesterol-lowering agent, which competitively inhibits the enzyme HMG-CoA reductase. Several HPLC methods for its analysis have been developed but there is no report of its determination using capillary electrophoresis (CE). In this paper, we report the development of a simple CE method for lovastatin determination, which is selective with respect to its degradation products and useful for routine analyses. Since the molecule of lovastatin in its lactone form is uncharged and is only slightly soluble in water, base hydrolysis was used to open the lactone ring and transform the compound into a water-soluble acid form, which is negatively charged. Different solvents, different amounts of NaOH added, different hydrolysis times and different temperatures for sample preparation were tested. The CE and HPLC methods are compared in terms of susceptibility, precision, linearity and accuracy. HPLC method was found to be more susceptible and more precise.

Oxidative instability of the hydroxy methylglutaryl Co-A reductase inhibitor lovastatin in the solid state and stabilization with natural antioxidants (ascorbic acid, rutin, gallic acid, quercetin and caffeic acid) was investigated. Lovastatin in the solid state and binary mixtures with 10% (w/w), 25% (n/n), 12.5% (n/n) and 6.3% (n/n) of each of the antioxidants were prepared. Oxidation experiments were performed on the scanning calorimeter using dynamic oxygen atmosphere. The amount of non-oxidized lovastatin was determined using HPLC. The results of the experiments have shown that lovastatin is unstable to oxidation under higher temperatures and in the presence of oxygen, and that some antioxidants markedly stabilize the drug. The most significant antioxidative effect was seen with caffeic acid and rutin, followed by gallic acid and quercetin. Ascorbic acid was only moderately effective. The results prove that flavonoids do have significant antioxidative potential. This phenomenon can be used to improve oxidative stability of drugs such as lovastatin which are sensitive to the presence of oxygen.