Small Biogas Plant Stability Prediction Model

In this paper stability prediction for a small biogas plant in islanded mode depending on local consumers energy consumption growth is given. Biogas plant with two cogeneration facilities and local consumers is tested for on grid and islanded operation and thus represents a microgrid. Generator and regulator modelling as well as surrounding electrical grid modelling in software package Power World Simulator are described. Expected consumption growth through the period of 20 years in microgrid area is simulated. All generator important variables, i.e. voltage, frequency, real and reactive power in case of islanded mode are examined and explained. Finally, stability prediction analysis of biogas plant and surrounding consumers for 20 years period is given

Mass Flow Meter Analysis for Reliable Measuring

The aim of this paper is to show how to analyze and correctly chose measuring device specially applied on mass flow meter based on Coriolis principle. In the beginning short description of Coriolis based mass flow meter is given. Furthermore, comparison analysis of two flow meters shows where are the problems of wrongly applied method in slurry fluid measurement in production of powder detergents plant. Analysis is made using RS Logix 500 program. In given diagrams which show causes of wrong measurements and position of mass flow device the few malfunctions are determined Finally, using comparison measurement with new mass flow meter shows that measurement method is applicable for slurry fluids which are specially problematic and complex for measuring

Mass Flow Meter Analysis for Reliable Measuring

The aim of this paper is to show how to analyze and correctly chose measuring device specially applied on mass flow meter based on Coriolis principle. In the beginning short description of Coriolis based mass flow meter is given. Furthermore, comparison analysis of two flow meters shows where are the problems of wrongly applied method in slurry fluid measurement in production of powder detergents plant. Analysis is made using RS Logix 500 program. In given diagrams which show causes of wrong measurements and position of mass flow device the few malfunctions are determined Finally, using comparison measurement with new mass flow meter shows that measurement method is applicable for slurry fluids which are specially problematic and complex for measuring

Stability Testing of a Small Biogas Plant in an Electric Power System

The aim of this paper is to test stability of a small biogas plant in an electric power system and the possibility of island mode as well. A short description of a biogas plant with two 1 MW generators is given in the introductory part. Furthermore, generator and regulator modeling as well as modeling of the surrounding electrical grid in software package PowerWorld Simulator are described. Operation simulations of this power system show that the system is stable in terms of short-period disturbances. Finally, the possibility of island mode operation of the biogas plant loaded with part of the surrounding electrical grid in the case of blackout is tested. It is shown that island mode is possible and reasonable in the case of longer blackout

Znanstveni kolokvij "Astronomske, satelitske i terestričke metode u geodeziji" povodom 80-og rođendana profesora emeritusa Nikole Solarića i profesora Miljenka Solarića

Opisan je znanstveni kolokvij "Astronomske, satelitske i terestričke metode u geodeziji", koji je održan 17. rujna 2014. na Geodetskom fakultetu povodom 80-og rođendana profesora emeritusa Nikole Solarića i profesora Miljenka Solarića

Usporedba u proizvodnji etanola iz kukuruza (Zea mays L.) između HTF hibrida i hibrida iz hrvatskih oplemenjivačkih programa

The aim of this study was to determine the differences in grain and ethanol yields between hybrids obtained from breeding programs in the Republic of Croatia and introduced HTF (High Total Fermentable) maize hybrids. The trial was conducted at three sites (Osijek, Beli Manastir and Zagreb) for two consecutive years (2012 and 2013) in three plant densities (60,000, 70,000 and 80,000 plants/ha). Pioneer HTF hybrids for the ethanol production were used as controls to assess the productivity of ethanol of hybrids from the Agricultural Institute Osijek and Bc Institute d.d. The study of ethanol production was carried out by using the Lemuz method. According to ANOVA statistical analysis, statistically significant differences in grain and ethanol yields were not found between HTF hybrids and hybrids of domestic breeding companies. Statistically significant difference was found in ethanol yield by sites (P<0.05) with highest average ethanol yield determined at Beli Manastir and the lowest in Osijek. Site × year × plant density interaction showed statistically significant difference in ethanol yield between hybrids and the most productive was the OS378 hybrid. Ethanol production of hybrids designated for this purpose did not produce higher ethanol yields than domestic hybrids from the same amount of grain.Cilj istraživanja bio je utvrditi razliku u proizvodnji zrna i etanola iz kukuruza između domaćih hibrida kukuruza koji se uobičajeno koriste za proizvodnju zrna i uvezenih HTF (High Total Fermentable) deklariranih hibrida za proizvodnju etanola. Poljski pokus je postavljen na 3 lokacije (Osijek, Beli Manastir, Zagreb) dvije godine uzastopno (2012, 2013) u tri gustoće sklopa (60,000, 70,000 i 80,000 biljaka/ha). Hibridi tvrtke Pioneer, deklarirani kao “HTF” hibridi za proizvodnju etanola iz zrna kukuruza korišteni su kao kontrola za procjenu produktivnosti etanola iz domaćih hibrida Poljoprivrednog instituta Osijek i Bc Instituta d.d. Laboratorijska proizvodnja etanola utvrđena je Lemuz metodom. Sukladno ANOVA statističkoj analizi nisu utvrđene statistički značajne razlike u prinosu zrna i etanola između HTF hibrida i hibrida domaćih oplemenjivačkih kuća. Statistički značajna razlika utvrđena je u prinosu etanola po lokalitetima (P<0.05) gdje je prosječno najveći prinos etanola ostvaren u Belom Manastiru, a najmanji u Osijeku. Interakcija lokalitet × godina × gustoća biljaka imala je statistički značajan utjecaj na prinos etanola između hibrida, a najproduktivniji je bio hibrid OS378. Deklarirani namjenski hibridi za proizvodnju etanola nisu proizveli više etanola u odnosu na domaće hibride iz iste količine zrna kukuruza

Znanstveni kolokvij „Astronomske, satelitske i terestričke metode u geodeziji“ u povodu 80. rođendana profesora emeritusa Nikole Solarića i profesora Miljenka Solarića

The scientific colloqium Astronomical, satellite and terrestrial methods in geodesy was organized on the occasion of 80th birthday of Professor Emeritus Nikola Solarić and Professor Miljenko Solarić (Fig.1) by members of the Chair for Satellite Geodesy, Faculty of Geodesy, University of Zagreb, Professor Željko Bačić and Professor Drago Špoljarić together with colleagues from the Chair for Surveying Professor Đuro Barković and Assistant Professor Mladen Zrinjski as well as with Assitant Professor Milan Rezo, the president of Croatian Geodetic Association on September 17, 2014.U svečanom ozračju dana 17. rujna 2014. godine održan je na Geodetskom fakultetu Sveučilišta u Zagrebu znanstveni kolokvij Astronomske, satelitske i terestričke metode u geodeziji, koji su u povodu 80. rođendana profesora emeritusa Nikole Solarića i profesora Miljenka Solarića (slika 1) organizirali djelatnici Katedre za satelitsku geodeziju profesori Željko Bačić i Drago Špoljarić u suradnji s kolegama s Katedre za zemljomjerstvo profesorom Đurom Barkovićem i docentom Mladenom Zrinjskim te docentom Milanom Rezom, predsjednikom Hrvatskoga geodetskog društva

Znanstveni kolokvij "Astronomske, satelitske i terestričke metode u geodeziji" povodom 80-og rođendana profesora emeritusa Nikole Solarića i profesora Miljenka Solarića

Opisan je znanstveni kolokvij "Astronomske, satelitske i terestričke metode u geodeziji", koji je održan 17. rujna 2014. na Geodetskom fakultetu povodom 80-og rođendana profesora emeritusa Nikole Solarića i profesora Miljenka Solarića

Scientific Colloquium “Astronomical, Satellite and Terrestrial Methods in Geodesy” on Occasion of 80th Birthday of Professor Emeritus Nikola Solarić and Professor Miljenko Solarić

The scientific colloqium Astronomical, satellite and terrestrial methods in geodesy was organized on the occasion of 80th birthday of Professor Emeritus Nikola Solarić and Professor Miljenko Solarić (Fig.1) by members of the Chair for Satellite Geodesy, Faculty of Geodesy, University of Zagreb, Professor Željko Bačić and Professor Drago Špoljarić together with colleagues from the Chair for Surveying Professor Đuro Barković and Assistant Professor Mladen Zrinjski as well as with Assitant Professor Milan Rezo, the president of Croatian Geodetic Association on September 17, 2014

Carotid Endarterectomy Unexpectedly Resulted in Optimal Blood Pressure Control

Resistant hypertension is defined as hypertension that remains above 140/90 mmHg despite the provision of three or more antihypertensive drugs in a rational combination at full doses and including a diuretic. It is associated with adverse clinical outcome and therefore requires aggressive medical treatment. We present a case of 70-year-old woman who was treated for resistant hypertension with a diuretic, ACE-inhibitor, calcium channel blocker, and with centrally acting antihypertensive, moxonodine. Despite of aggressive medical treatment her blood pressure remained above 160/90 mmHg continuously. Large diagnostic workup excluded common causes of secondary hypertension, but revealed significant carotid stenosis present on left internal carotid artery. Carotid endarterectomy was performed in order to improve cerebrovascular prognosis, but unexpectedly resulted in optimal control of her blood pressure. Two months after operation patient was on only one antihypertensive drug, having blood pressure below 130/85 mmHg. We suggest that in selected patients resistant hypertension could be associated with carotid stenosis and carotid sinus baroreceptor dysfunction. For definite conclusions further studies are warranted