Overimplicit multistep methods

summary:The paper is concerned with the numerical solution of ordinary differential equations by a new class of methods called overimplicit multistep methods. The effort is devoted to the study of the convergence and $A$-stability of the introduced methods. $A$-stable formulae of arbitrarily high orders are shown to exist in this new class. This implies the efficiency of using these methods for stiff problems

Fabrication of Europium-Doped CaF2 Films via Sol-Gel Synthesis as Down-Shifting Layers for Solar Cell Applications

In the present work, an in-depth study on the sol-gel process for the fabrication of Eu-doped CaF2 materials in the form of thin films has been addressed for the production of down-shifting layers. Fine-tuning of the operative parameters, such as the annealing temperature, substrate nature and doping ion percentage, has been finalized in order to obtain Eu(III)-doped CaF2 thin films via a reproducible and selective solution process for down-shifting applications. An accurate balance of such parameters allows for obtaining films with high uniformity in terms of both their structural and compositional features. The starting point of the synthesis is the use of a mixture of Ca(hfa)(2)center dot diglyme center dot H2O and Eu(hfa)(3)center dot diglyme adducts, with a suited ratio to produce 5%, 10% and 15% Eu-doped CaF2 films, in a water/ethanol solution. A full investigation of the structural, morphological and compositional features of the films, inspected using X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray analysis (EDX), respectively, has stated a correlation between the annealing temperature and the structural characteristics and morphology of the CaF2 thin films. Interestingly, crystalline CaF2 films are obtained at quite low temperatures of 350-400 degrees C. The down-shifting properties, validated by taking luminescence measurements under UV excitation, have allowed us to correlate the local environment in terms of the degree of symmetry around the europium ions with the relative doping ion percentages

Europe, Integration and (Yugoslav) Migration

Rasprava počinje tvrdnjom da je Evropa kakvu danas poznajemo nastala u srednjem vijeku, u procesu intenzivnih migracija. U tom kontekstu jugoslavenski prostor bio je specifičan jer je jedino ovdje novi etnokulturni superstrat prevagnuo nad romaniziranim supstratom i stvorio svojstven amalgam koji stoljećima neće pripasti ni Zapadu ni Istoku. S druge strane, pokazuje se da su migracije i usporedbe sa stranim kulturama djelovale na stvaranje pojma Evrope i evropejstva koji se, međutim, sve više sužavao na zapadni dio kontinenta. Autori zatim prelaze na prikaz razvitka konkretnih oblika (zapadno)evropske integracije u 20. stoljeću (osobito EEZ), te na pregled trendova poslijeratne migracije u Evropi i u Evropskoj zajednici. Iz tog pregleda proizlazi da je, unatoč razvoja jedinstvenog tržišta radne snage unutar EEZ, došlo do pada udjela »unutrašnjih« migranata, a do povećavanja broja i udjela migranata iz tzv. trećih zemalja. Taj proces počeo je u fazi visoke konjunkture prije 1973. mada se nastavio i poslije, i to uslijed spajanja migrantskih obitelji u zemljama primitka, prirodnog priraštaja među samim migrantima, ilegalne migracije i priljeva azilanata. Najveći apsolutni i relativni porast bilježila je turska migrantska populacija, kao i neke druge grupacije afro-azijskih migranata. S druge strane, jugoslavenska migrantska populacija u zemljama EEZ opada i zatim stagnira od sredine 1970-ih, a u sadašnjem desetljeću broji nešto više od 700.000 migranata. Autori, međutim, smatraju da bi danas, u ovom trenutku ozbiljne ekonomske i društveno-političke krize u zemlji, migracijski potencijal Jugoslavije mogao iznositi čak dva milijuna ljudi. Na kraju rada autori nude tri moguća scenarija za jugoslavensku migraciju s obzirom na buduću poziciju Jugoslavije (i njezina sistema) u procesu evropske integracije.The paper begins by claiming that Europe as we know it today was formed in the Middle Ages in the wake of intense migration. In this context the territory of Yugoslavia was specific, since only here did a new ethnocultural superstratum prevail over the Romanised substratum so as to form a distinct amalgam that for centuries did not belong either to the West or the East. Furthermore, the authors show that the concept of Europe and Europeanism developed due to migration and comparison with foreign cultures, yet that it gradually came to be confined to the western part of the continent. The authors continue on to examine the development of concrete forms of (West) European integration in the 20th century – especially the EEC – and then give a review of migration trends in post-war Europe and in the European Community. From this review it can be deduced that – despite the creation of a common EEC labour market – the proportion of ‟internal” migrants in the EEC fell, while the number and proportion of migrants from so called ‟third” countries increased. This process began in the economically expansive years before 1973, but has since continued due to reunions of migrant families in host countries, natural growth of migrant populations, clandestine migration and refugee flows. The largest absolute and relative increase was registered in regard to the Turkish migrant population, but also among other groups of migrants from Africa and Asia. On the other hand, the Yugoslav migrant population in the EEC fell and then stagnated since the mid-1970s, so that at present it numbers a little over 700,000. The authors, however, estimate that today – at a time of serious economic and socio-political crisis in the country – Yugoslavia’s migration potential could amount to as much as two million people. At the end of the paper the authors present three possible scenarios for Yugoslav migration, which they base on an evaluation of the future position of Yugoslavia (and its socio-economic system) in the process of European integration

Vzaimootnošenija bazovyh dvigatel\u27nyh sposobnostej i uspešnosti v basketbole

Povezanost bazičnih motoričkih sposobnosti definiranih kao koordinacija, realizacija ritmičkih struktura, ravnoteža, frekvencija pokreta, brzina pokreta, preciznost fleksibilnosti, sila, eksplozivna snaga, snaga i izdržljivost, i dva skupa varijabli uspješnosti u igri, analizirana je na temelju rezultata 53 studenata Fakulteta za fizičku kulturu, osrednjeg košarkaškog znana, primjenom podataka za maksimiranje kovarijanci među skupovima varijabli. Prvi skup varijabli uspješnosti predstavljale su situaciono-motoričke sposobnosti nominirane kao preciznost dodavanja, preciznost ubacivanja, manipuliranje loptom, efikasnost kretanja sa i bez lopte i snaga izbačaja lopte. Drugi skup je predstavljao osam ocjena uspješnosti u igri i to ocjene tehnike, efikasnost u napadu, stvaralaštva, odgovornosti, angažiranosti i opće uspješnosti u igri. Utvrđena je značajna i pozitivna povezanost između bazičnih motoričkih sposobnosti i oba skupa varijabli uspješnost kao i svake pojedinačne dimenzije uspješnosti sa skupom primarnih motoričkih faktora. Najveći doprinosi povezanosti skupova imale su eksplozivna snaga, koordinacija, te sila, frekvencija, pokret i izdržljivost.The aim of the investigation was to establish the degree of relationship between motoric abilities and the dimensions on which performance in basketball is dependent. Basic motoric abilities, defined as latent dimensions were obtained by means of 74 tests of motoric abilities carried out on a group of 208 students of the Faculty of Physical Education (Metikos, Prot, Horvat, Kules and Hofman, 1982). For the present investigation a subgroup of 53 subjects was taken, tested for situational motoric abilities and their performance in basketball was evaluated (Blaskovic, Milanovic and Matkovic, 1982; Blasković, Milanovic, 1983). The predictive set of basic motoric abilities was represented by the following dimensions: 1. coordination (KOORDI) 2. realization of rythmic structures (RITAM) 3. BALANCE (BALANS) 4. frequency of movements (BRZOFR) 5. speed of movements (BRZJEP) 6. precision (PRECIZ) 7. flexibility (FLEKSI) 8. force (DIMSIL) 9. explosive power (EKSPLO) 10. power (REPSTA) 11. endurance (IZDRZL) The first set of criterial variables was defined as situational motoric abilities of basketball players which were as follows: 1. precision of passing (PRECDO) 2. precision of shooting (PRECUB) 3. manipulation with the ball (MANLOP) 4. efficacy of movement with and without the ball (EFKRET) 5. ball-throwing power (SNAIZB) The second set of criterial variables was extracted on the basis of evaluations of independent judges who observed each subject over four matches and awarded points for: 1. technique (TEHNIK) 2. efficacy in attack (NAPAD) 3. efficacy in defence (OBRANA) 4. creativity (STVARA) 5. responsibility (ODGOVO) 6. commitment (ANGAZI) 7. behaviour (PONASA) 8. general performance (OPCOCJ) The relationship between basic motoric abilities and each of the sets of criterial variables was estimated by means of QCR canonical analysisi of covariance (Momirovic, Dobric and Karaman, 1983) and the SRA stupid regression analysis (Stalec and Momirovic). The results obtained show a significant and relatively high correlation between basic motoric abilities and situational motoric abilities, and a significant but only moderate correlation between the predictive set and evaluations of performance in the game. This indicates that there is a relatively good possibility of using basic motoric abilities as the basis for a prognosis of situational motoric abilities. The possibility of predicting successful performance in the game by using the set of primary is considerably less in view of the great complexity of the game of basketball. In all the analysis the greatest contribution to the prognosis was given primarily by explosive power and coordination, and then by power, frequence of movements and endurance. The influence of precision (as basic motoric dimensions) on the correlation between the sets is very weak. In view of the importance of precision in basketball, this result puts forward the necessity for further research into the field of precision., both in the basic motoric space and that of situational motoric abilities of basketball players. At the same time it is necessary to carry out this investigation on a group of good players in order to gain a more complete insight into the correlation between basic motoric abilities and performance in basketball

Efikasnost kombinacija nespecifičnih i fungicida iz grupe strobilurina u suzbijanju čađave pegavosti jabuke

The efficacy of several fungicide mixtures in controlling Venturia inaequalis in apple was evaluated in field trials. The efficacies of Flint Plus (trifloxystrobin + captan) and Tercel (pyraclostrobin + dithianon) in comparison with standard fungicides Zato 50-WG (trifloxystrobin) and Stroby + Delan (kresoxim-methyl + dithianon) were tested in the localities Mihajlovac, Radmilovac and Landol in 2004 and 2005. Both tested fungicides exhibited high efficacy in controlling apple scab. There were significant differences in the efficacies of Flint Plus (91.3-98.5%) and Zato 50-WG (68.2% and 78.4%); and Tercel (88.7-93.5%) and Stroby + Delan (77.9% and 82.1%). Our experiments showed that the investigated fungicide mixtures are highly effective against V. inaqeulais, even under high disease pressure.Ispitivana je efikasnost nekoliko kombinacija fungicida u suzbijanju Venturia inaequalis na jabuci u poljskim uslovima. U 2005-oj i 2006-oj godini ispitivana je efikasnost Flint Plus (trifloksistrobin + kaptan) i Tercel (piraklostrobin + ditianon) u odnosu na standardne fungicide Zato 50-WG (trifloksistrobin) i Stroby + Delan (kresoksim-methil + ditianon) na lokalitetima Mihajlovac, Radmilovac i Landol. Oba ispitivana fungicida ispoljila su visoku efikasnost u suzbijanju čađave pagavosti jabuke. Između efikasnosti Flint Plus (91.3-98.5%) i Zato 50-WG (68.2% i 78.4%), i Tercel (88.7-93.5%) i kombinacije fungicida Stroby + Delan (77.9% i 82.1%) zabeležena je statistički značajna razlika. Naši ogledi su pokazali da su ispitivane kombinacije fungicida visoko efikasne protiv V. inaequalis čak i u uslovima jake zaraze

CHP and CCHP Systems Today

The concept of the CCHP system (combined cooling, heating and power - combined cooling, heating and electricity generation) is described in this paper. The development of CCHP systems comes from the CHP system (combined heat and power generation), also known as cogeneration. CHP systems generate electricity from fuel combustion, heat as a by-product may contain even 60% to 80% of the total potential energy, and may be re-used for different applications. CHP is generally defined as the combined production of electricity (or mechanical) energy and useful thermal energy from the same primary energy source. Rated power of most of centralized power plants and industries which use CHP system exceeds 1 MW. Rated power of CCHP systems varies over a wide power range from 1 kW to 500 MW. CCHP systems have high potentials in different forms of energy supply

Efikasnost mandipropamida za suzbijanje prouzrokovača plamenjače krompira u poljskim uslovima

The efficacy of mandipropamid (Revus 250 SC) in controlling Phytophthora infestans in potato was evaluated in field trials. The efficacies of Revus 250 SC in comparison with standard fungicides Quadris (azoxystrobin) were tested in several localities in Serbia (Kasarske Livade, Valjevska Kamenica and Opovo) in 2007 and 2008. Both of the tested fungicides exhibited high efficacy in controlling potato late blight. The differencies in the efficacy of Revus 250 SC (96.3- 99.2%) and Quadris (94.1-95.5%) were insignificant. Our experiments showed that the investigated fungicide was highly effective against P. infestans even under high disease pressure.Ispitivana je efikasnost mandipropamida (Revus 250 SC) za suzbijanje Phytophthora infestans u usevu krompira u poljskim uslovima. Efikasnost preparata Revus 250 SC ispitivana je na nekoliko lokaliteta u Srbiji (Kasarske Livade, Valjevska Kamenica i Opovo) tokom 2007. i 2008. godine. Kao standard poslužio je Quadris (azoksistrobin). Oba ispitivana fungicida su ispoljila visoku efikasnost u suzbijanju prouzrokovača plamenjače krompira. Između efikasnosti Revus 250 SC (96.3- 99.2%) i Quadris (94.1-95.5%) nije utvrđena statistički značajna razlika. Naši ogledi su pokazali da je ispitivani fungicid visokoefikasan u suzbijanju P. Infestans, čak i u uslovima jake zaraze

A biomechanical assessment of modular and monoblock revision hip implants using FE analysis and strain gage measurements

<p>Abstract</p> <p>Background</p> <p>The bone loss associated with revision surgery or pathology has been the impetus for developing modular revision total hip prostheses. Few studies have assessed these modular implants quantitatively from a mechanical standpoint.</p> <p>Methods</p> <p>Three-dimensional finite element (FE) models were developed to mimic a hip implant alone (Construct A) and a hip implant-femur configuration (Construct B). Bonded contact was assumed for all interfaces to simulate long-term bony ongrowth and stability. The hip implants modeled were a Modular stem having two interlocking parts (Zimmer Modular Revision Hip System, Zimmer, Warsaw, IN, USA) and a Monoblock stem made from a single piece of material (Stryker Restoration HA Hip System, Stryker, Mahwah, NJ, USA). Axial loads of 700 and 2000 N were applied to Construct A and 2000 N to Construct B models. Stiffness, strain, and stress were computed. Mechanical tests using axial loads were used for Construct A to validate the FE model. Strain gages were placed along the medial and lateral side of the hip implants at 8 locations to measure axial strain distribution.</p> <p>Results</p> <p>There was approximately a 3% average difference between FE and experimental strains for Construct A at all locations for the Modular implant and in the proximal region for the Monoblock implant. FE results for Construct B showed that both implants carried the majority (Modular, 76%; Monoblock, 66%) of the 2000 N load relative to the femur. FE analysis and experiments demonstrated that the Modular implant was 3 to 4.5 times mechanically stiffer than the Monoblock due primarily to geometric differences.</p> <p>Conclusions</p> <p>This study provides mechanical characteristics of revision hip implants at sub-clinical axial loads as an initial predictor of potential failure.</p

Efikasnost biofungicida Polyversum™ u suzbijanju Botrytis cinerea Pers. na plodovima maline

Efficacy of a biological fungicide product, Polyversum™ (Pythium oligandrum Drechsler), in controlling grey mould of raspberries Botrytis cinerea Pers. was tested at sites around Valjevo, Požega and Šabac in 2004, 2005 and 2006. The experiments were conducted and data processed using EPPO methods. Efficacy was found to be significantly lower statistically in the experimental variants involving Polyversum™ biofungicide (E = 18.0%-53.9%) than the standard botricide Ronilan- DF (E = 56.6%-90.3%). Our results show that the biological product Polyversum™ achieved significant efficacy although poorer than the standard fungicide Ronilan-DF. As it is a biological product almost entirely free of any toxicological and ecotoxicological limitations, it offers a significant advantage for widespread usage in plant protection.U toku 2004, 2005. i 2006. godine, na lokalitetima Valjeva, Požege i Šapca, ispitivana je efikasnost biološkog preparata Polyversum ™ (Pythium oligandrum Drechsler) u suzbijanju prouzrokovača sive truleži plodova maline Botrytis cinerea Pers. Eksperimenti su izvedeni i podaci obrađeni po metodama EPPO. Utvrđeno je da je u varijantama primene biofungicida Polyversum ™ efikasnost (E=18.0%- 53.9%) statistički značajno slabija od standardnog botriticida Ronilan- DF (E=56.6%-90.3%). Ispoljena efikasnost biološkog preparata Polyversum je značajna, iako slabija od standardnog fungicida Ronilan- DF. S obzirom da je reč o biološkom preparatu koji gotovo da nema toksikoloških i ekotoksikoloških ograničenja, to mu daje značajnu prednost za širu upotrebu u zaštiti bilja