Synthetic, Crystallographic, and Computational Study of Copper(II) Complexes of Ethylenediaminetetracarboxylate Ligands

Copper(II) complexes of hexadentate ethylenediaminetetracarboxylic acid type ligands H4eda3p and H4eddadp (H4eda3p = ethylenediamine-N-acetic-N,N′,N′-tri-3-propionic acid; H4eddadp = ethylenediamine-N,N′-diacetic-N,N′-di-3-propionic acid) have been prepared. An octahedral trans(O6) geometry (two propionate ligands coordinated in axial positions) has been established crystallographically for the Ba[Cu(eda3p)]·8H2O compound, while Ba[Cu(eddadp)]·8H2O is proposed to adopt a trans(O5) geometry (two axial acetates) on the basis of density functional theory calculations and comparisons of IR and UV−vis spectral data. Experimental and computed structural data correlating similar copper(II) chelate complexes have been used to better understand the isomerism and departure from regular octahedral geometry within the series. The in-plane O−Cu−N chelate angles show the smallest deviation from the ideal octahedral value of 90°, and hence the lowest strain, for the eddadp complex with two equatorial β-propionate rings. A linear dependence between tetragonality and the number of five-membered rings has been established. A natural bonding orbital analysis of the series of complexes is also presented.

Uncinula necator (Schow) Burr., prouzrokovač pepelnice vinove loze: infekcioni potencijal i mikroklimatski uslovi

Microclimate in Podgorica vineyards and its effect on the formation, maturing and rupturing of cleistothecia, and disease outbreak, was studied. An analysis of collected data on minimum and maximum temperatures and precipitation over the periods November-April (2001/2002, 2002/2003 and 2003/2004) and April-July (2002, 2003 and 2004) and their comparison with the average values over a 50-year period, indicate that neither temperature nor precipitation act as a limiting factor for disease outbreak and development in Podgorica vineyards. Over the trial period, conditions were favourable for the formation and maturing of cleistothecia between November and April. A sum of 1100ºC mean daily temperature was reached by mid-March. From bud burst to end of vine flowering, the conditions were again nearly optimal both for ascospore release from cleistothecia and primary infection, and for secondary infection. Initial symptoms appeared on lower leaves and inflorescences. Cleistothecia appeared in all green parts of grapevine. In 2002, and 2004, conditions were favourable for a secondary infection of bunches, leaves and canes from April to mid-July. Conditions for secondary infection were less favourable in the second half of June 2003. That year was characterized by warmer weather with less rainfall, especially in June and July. In 2004, precipitation and temperature were lower than in 2002, which resulted in a slightly less severe outbreak of disease.U ovom radu su analizirani mikroklimatski uslovi u podgoričkom vinogorju i njihov značaj za formiranje, sazrevanje i pražnjenje kleistotecija, kao i za pojavu i razvoj oboljenja. Prikupljanjem i analizom podataka o minimalnim i maksimalnim temperaturama i padavinama tokom perioda novembar – april (2001/2002, 2002/2003. i 2003/2004) i perioda april – jul (2002, 2003. i 2004) i njihovim poređenjem sa pedesetogodišnjim prosekom konstatovano je da u podgoričkom vinogorju ni temperatura niti padavine nisu ograničavajući faktor za pojavu i razvoj oboljenja. Tokom trajanja ispitivanja postojali su povoljni uslovi za formiranje i sazrevanje kleistotecija u periodu od novembra do aprila. Suma srednjih dnevnih temperatura od 1100°C postiže se do polovine marta. U periodu od pucanja pupoljaka do fenofaze precvetavanja vinove loze, takođe, postojali su gotovo optimalni uslovi, kako za oslobođenje askospora iz kleistotecija i primarno zaražavanje, tako i za sekundarno zaražavanje. Prvi simptomi javljaju se na donjem lišću i na cvastima. Kleistotecije se javljaju na svim zelenim delovima vinove loze. Tokom 2002. i 2004. godine bili su povoljni uslovi za sekundarno zaražavanje grozdova, lišća i lastara, od aprila do kraja jula. I uslovi za sekundarno zaražavanje bili su manje povoljni u drugoj polovini juna 2003. godine. Ovu godinu karakterisalo je toplije vreme sa manje padavina, posebno tokom juna i jula. U 2004. godini padavine su bile slabije a temperature niže nego 2002, što je rezultiralo nešto slabijom pojavom oboljenja

Uncinula necator (Schow) Burr.: efikasnost pojedinačnih fungicida u proizvodnim uslovima i na kalemovima

The efficacy of several fungicides based on sulphur, propiconazole, kresoxim-methyl and pyrazophos was examined under production conditions and on scions in Podgorica environs over three successive years (2002, 2003 and 2004). The experiments were conducted based on EPPO methodology (1997) and data statistically processed. Infestation with grape powdery mildew was found to be more intensive under production conditions than on scions in each year of investigation. The heaviest infestation was on the bunches and than on shoots and leaves. The most evident difference in fungicide efficacy was also found on the bunches. Kresoxim-methyl demonstrated the highest average efficacy. Propiconazole was highly effective, while the efficacy of pyrazophos and sulphur was lower, and the intensity of disease, compared to control, was very significantly lower in statistical terms.U proizvodnim uslovima i na kalemovima, na području Podgorice, tokom tri eksperimentalne godine (2002, 2003. i 2004) ispitivana je efikasnost preparata na bazi sumpora, penkonazola, kresoksim-metila i pirazofosa. Eksperimenti su izvedeni po metodama EPPO (1997), a rezultati su odgovarajuće statistički obrađeni. Utvrđeno je da se pepelnica vinove loze svake godine intenzivnije javljala u proizvodnim uslovima nego na kalemovima. Takođe, najjači napad pepelnice bio je na grozdovima, slede lastari, pa listovi. Na grozdovima je i najizraženija razlika u efikasnosti ispitivanih fungicida. Najveću prosečnu efikasnost ispoljio je kresoksim-metil. Vrlo efikasan do efikasan je bio penkonazol, a manje efikasni su bili pirazofos i sumpor, ali je i kod njih intenzitet oboljenja u poređenju sa kontrolom, takođe, bio vrlo značajno manji

Uncinula necator (Schow) Burr., prouzrokovač pepelnice vinove loze: značaj zimskog i ranog proletnjeg tretiranja biljaka

Three preceding articles (Miladinoviæ et al., 2007a, 2007b, 2007c) covered the state-ofthe art on the pathogen and disease, the source of inoculum and pathogen infection potential, and the microclimatic conditions of Pogdorica Vineyards. This segment of the study focuses on winter and early spring treatments of grape vine for its protection from Uncinula necator, the causal agent of powdery mildew. The effects of winter and early spring treatments were investigated under production conditions over a period of three experimental years (2002, 2003 and 2004). Winter treatment was conducted with products based on DNOC and copper hydroxide, and early spring with pirazophos. During the rest of the vegetation season, the same treatments were carried out in all test variants with products based on penconazole, kresoxim-methyl and sulphur, and their combinations. Winter treatment with products based on DNOC was found to lead to a significant statistical decrease in disease intensity, even without any further treatments over the vegetation season. The products based on copper hydroxide provided weaker protection. After winter treatment, early spring treatment was not found to have a significant effect. However, when winter treatment was missing, early treatment in the spring was very important, especially for the protection of bunches.U ranijim radovima (Miladinović i sar., 2007a, 2007b, 2007c) sagledana su dosadašnja saznanja o patogenu i oboljenju, izvoru inokuluma i infekcionom potencijalu patogena i mikroklimatskim uslovima u podgoričkom vinogorju. Ovim radom obuhvaćeni su zimsko i rana proletnja tretiranja vinove loze radi suzbijanja Uncinula necator, odnosno njene zaštite od pepelnice. U proizvodnim uslovima, tokom tri eksperimentalne godine (2002, 2003. i 2004), ispitivan je značaj zimskog i ranih proletnjih tretiranja. Zimsko tretiranje je obavljano preparatima na bazi DNOC ili bakaroksihlorida, a rano proletnje preparatom na bazi pirazofosa. U ostalom delu vegetacije izvedena su ista tretiranja u svim ispitivanim varijantama i to preparatima na bazi penkonazola, kresoksim-metila i sumpora i njihovih kombinacija. Utvrđeno je da se zimskim tretiranjem biljaka preparatima na bazi DNOC postiže statistički značajno smanjenje intenziteta oboljenja, čak i ako se tokom vegetacione sezone ne vrši suzbijanje pepelnice. Preparatima na bazi bakaroksihlorida postizana je slabija zaštita. Po obavljenom zimskom tretiranju rano proletnje tretiranje nema poseban značaj. Ali, ako zimsko tretiranje nije izvedeno, rano tretiranje biljaka ima veliki značaj, posebno sa stanovišta zaštite grozda

Uncinula necator (Schow) Burr., prouzrokovač pepelnice vinove loze: značaj, osobine i mogućnosti suzbijanja

The article is an overview of what we know at present about the patogen Uncinula necator and the disease powdery mildew of grapevine, i.e. its economic status, inoculum source, microclimate conditions, vine susceptibility and principles of its protection. Powdery mildew is a major grapevine disease in terms of losses. It infects the plant’s green parts, reducing its fertility, spoiling the quality of grapes and wine and ruining plant vitality. The process additionally affects subsequent vegetation seasons. The disease occurs every year and its intensity depends on a number of factors. It had long been assumed that overwintering mycelium was the primary source of inoculum. More recent research, however, has revealed a crucial role of cleistothecia in many vineyards. They were found in our vine-growing regions long ago but their true role in the epidemiology of disease has been explained only recently. Microclimate conditions considerably affect the abundance and vitality of cleistothecia and the pathogen’s infection potential. Outbreaks and intensity of disease both depend on them, while vine susceptibility plays another important role, depending on cultivar and plant ontogenesis. Grapevine is most sensitive during flowering and bunch formation when conditions are generally good for the disease to appear and spread. Temperature, precipitation and relative air humidity may limit the occurrence of powdery mildew, but extreme values in that respect are a rarity. Their normal scope is more or less favourable for the disease, especially in Podgorica vineyards. Knowing the pathogen, especially its infection potential, environmental conditions, dynamics of host development and timely and good quality protection of vines, both preventive and chemical, is crucial for grapevine protection. Prevention is important but treatments with fungicides are crucial for U. necator control, and they can either focus on destroying the inoculum and delaying mildew outbreaks or on preventing primary and secondary infection and spreading of disease. Fungicides that are normally used include some old compounds (sulphur, dinocap) as well as new ones (strobilurins and hinolines), while inhibitors of ergoserol biosynthesis have an increasing role.Ovim radom učinjen je osvrt na prethodna saznanja o patogenu Uncinu­la necator i oboljenju pepelnica vinove loze: o ekonomskom značaju, izvoru inokuluma, mikroklimatskim uslovima, osetljivosti vinove loze i načelima njene zaštite. Pepelnica pripada grupi ekonomski najznačajnijih oboljenja vinove loze. Napada sve zelene delove biljaka i dovodi do smanjenja rodnosti, kvaliteta grožđa i vina i slabi vitalnost biljaka. To se odražava i na naredne vegetacione sezone. Javlja se svake godine, a intenzitet njene pojave zavisi od niza faktora. Dug o se smatralo da je prezimljujuća micelija osnovni izvor inokuluma. Potom je utvrđeno da kleistotecije imaju dominantnu ulog u u mnog im vinog orjima. U našim uslovima su odavno utvrđene, a njihov pravi značaj u epidemiologiji oboljenja sagledan je nedavno. Na brojnost i vitalnost kleistotecija, odnosno infekcioni potencijal patogena, značajno utiču mikroklimatski uslovi. Od njih zavise i vreme pojave i intenzitet oboljenja, kog a uslovljava i osetljivost vinove loze, a ona je različita zavisno i od sortimenta i od ontogeneze biljaka. Vinova loza je najosetljivija tokom cvetanja i formiranja grozda, kada redovno postoje uslovi za pojavu i širenje oboljenja. Temperatura, padavine i relativna vlažnost vazduha mog u biti ograničavajući faktori pojave pepelnice vinove loze, ali se njihovi ekstremi vrlo retko javljaju. Najčešće su u opseg u manje ili veće pogodnosti za jaku pojavu oboljenja, posebno u podgoričkom vinogorju. U zaštiti vinove loze osnovno je poznavanje patogena, posebno njegovog infekcionog potencijala, uslova sredine i dinamike razvića domaćina, kao i blagovremeno i kvalitetno izvođenje preventivne i hemijske zaštite. Preventivne mere zaštite imaju veliki značaj, ali okosnicu suzbijanja U. necator čini primena fungicida, koja može imati za cilj uništavanje inokuluma i odlaganje pojave pepelnice i/ ili sprečavanje primarnog i sekundarnog zaražavanja i širenja oboljenja. Spektar fungicida koji se koriste sadrži stara, odavno poznata jedinjenja (sumpor, dinokap), ali i nova (strobilurini i hnolinoni), a značajnu ulog­u imaju i inhibitori biosinteze erg­osterola

Uncinula necator (Schow) Burr.: izvor inokuluma u uslovima podgoričkog vinogorja

A study series has been organised to survey the present knowledge of the pathogen and disease, as well as microclimatic conditions in Podgorica vineyards, to examine the importance of winter treatments, proper choice of fungicide and time of treatment, and to plan out vine protection under the existing conditions and protection of scions in nurseries. This one and another article focus on the source of inoculum and the pathogen infection potential. In an experiment conducted over three years (2002, 2003 and 2004), the pathogen’s infection potential was investigated. The occurrence and numbers of white shoots, and the presence, time of maturing and beginning of cleistothecium rupturing were examined on the grape varieties Chardonnay, Cardinal, Vranac, Župljanka, Carignan and Grenage. Cleistothecia were identified as the main source of inoculum in Podgorica vineyards, and they were found to appear regularly, especially on susceptible cultivars such as Župljanka (up to 124/cm2), Chardonnay (up to 90/cm2) and Cardinal (up to 95/cm2). They also appear sporadically on the cultivar Vranac but were not observed on Carignan and Grenage. Cleistothecia abundance varied depending on grape variety, conditions existing in each trial year and exact location. They were most abundant in 2001/2002, less abundant in 2003/2004 and least so in 2002/2003. The abundance was also highest on leaf undersides, somewhat lower on the upper surface of leaves and lowest on canes, but it is the latter that is most important from the epidemiological aspect. White shoots were not found on any of the grape varieties examined, nor in any trial year.Radovima u nizu sagledana su dosadašnja saznanja o patogenu i oboljenju, mikroklimatskim uslovima u podgoričkom vinogorju, ispitani su značaj zimskog tretiranja, značaj izbora fungicida i vremena njihove primene i, projektovana je zaštita vinove loze u proizvodnim uslovima i zaštita kalemova u rastilu. Ovim radom obuhvaćena su ispitivanja izvora inokuluma i infekcionog potencijala patogena. U proizvodnim uslovima, tokom tri eksperimentalne godine (2002-2004) ispitivan je infekcioni potencijal patogena. Na sortama Šardone, Kardinal, Vranac, Župljanka, Karinjon i Grenaž praćena je pojava i brojnost belih mladara, pojava, vreme sazrevanja i početak pražnjenja kleistotecija. Utvrđeno je da su kleistotecije osnovni izvor inokuluma u ovom vinogorju, da se redovno formiraju, posebno na osetljivim sortama kao što su Župljanka (do 124 po cm2), Šardone (do 90 po cm2) i Kardinal (do 95 po cm2). Povremeno se javljaju i na Vrancu, a nisu se javljale na sortama Karinjon i Grenaž. Pored sortimenta vinove loze brojnost leistotecija varirala je zavisno od uslova u eksperimentalnim godinama, kao i od mesta njihove pojave. Najbrojnije su bile u 2001/2002. godini, manje brojne u 2003/2004. godini, a najmanje u 2002/2003. godini. Takođe, najbrojnije su bile na naličju lišća. Nešto su manje brojne na licu lišća, a najmanje brojne su na lastarima, ali je značaj kleistotecija sa lastara u epidemiologiji oboljenja najznačajniji. Beli mladari nisu utvrđeni ni na jednoj sorti vinove loze, niti u jednoj eksperimentalnoj godini

Isolation and Chemical Profile of Thymus Serpyllum L. and Lavandula Angustifolia Mill. Essential Oils

Aim of this study was to isolate essential oil from two different plants, Thymus serpyllum L. and Lavandula angustifolia Mill., as well to investigate their chemical composition. Essential oil was isolated by hydrodistillation, while chemical composition was established by GC-MS analysis. Obtained results showed that much more compounds were detected in Lavandula angustifolia Mill. than in Thymus serpyllum L. essential oil. Dominant compounds in Lavandula angustifolia Mill. were linalool (54.24%), eucalyptol (17.97%) and endo-borneol (13.36%), while thymol (37.37%), β-bisabolene (6.98%), germacrene D (6.68%) and trans-caryophyllene (6.47%) dominated in Thymus serpyllum L. essential oil

Impact of Selenium Addition to Animal Feeds on Human Selenium Status in Serbia

Research conducted during the 1980s demonstrated Se deficiency in humans. Increased inclusion of selenium in animal feeds started from the year 2000 onwards. The aim of this study was to estimate the effects of selenium inclusion in animal feeds on human selenium status and dietary habits of the Serbian population related to food of animal origin. Plasma selenium concentration in healthy adult volunteers, including residents of one of the regions with the lowest (Eastern Serbia, n = 60) and of one of the regions with the highest Se serum levels reported in the past (Belgrade, n = 82), was determined by hydride generation atomic absorption spectrometry. Multivariate analysis was employed to determine the correlation between Se plasma levels and dietary intake data derived from food frequency questionnaires and laboratory tests. The mean plasma Se level of the participants was 84.3 +/- 15.9 g/L (range: 47.3-132.1 g/L), while 46% of participants had plasma Se levels lower than 80 g/L. Frequency of meat, egg, and fish consumption was significantly correlated with plasma selenium level (r = 0.437, p = 0.000). Selenium addition to animal feed in the quantity of 0.14 mg/kg contributed to the improvement of human plasma selenium levels by approximately 30 mu g/L

Grid forming control for power converters based on an Inertial Phase Locked Loop (IPLL)

Inertia emulation is claimed to play a decisive role in the regulation and management of frequency in modern electrical systems. The support offered by renewable energy power plants and distributed generators is key to diminish the rate of change of frequency (RoCoF), as many synchronous generators are being replaced all around the globe. It is a reality that the implementation of the swing equation in the power converter control has been the core of several proposals on grid-forming controllers to emulate inertia. This kind of controller has been heavily studied and integrated in some demonstrators around the world during the last years, providing dynamic inertia support functionalities. However, the need to modify the synchronization strategy in already deployed power units has been one of the key opposition factors on industry, leading to a severe shortcoming on the integration. In contrast to the traditional swing equation implementation this paper presents a lightweight inertial phase-locked loop (IPLL) able to take the most of inertial features introducing minor changes on classical power converter control and synchronization structures. As shown in this work, the straightforward implementation significantly reduces the technological and computational effort compared to other synchronous emulation proposals. Moreover, it integrates not only dynamic inertial response to the converter, but also all grid-forming capacities to the power conversion unit. This modification on the synchronization structure enables the converter to work in grid-following mode in grid-tied applications, and grid-forming in islanded ones. The integration of the proposed IPLL, the stability analysis and a sample of its performance in HIL and experimental environments will be presented in this paper.This work was supported by the Margarita Salas Program promoted by the Spanish Ministry of Universities under Grant GA 94126.Peer ReviewedPostprint (published version

Photovoltaic grid-forming control strategy investigation using hardware-in-the-loop experiments

The frequency stability of a power system is of paramount importance, as a fast frequency swings in the system can lead to oscillatory instability, and thereby blackouts. A grid-connected microgrid, that can operate in the islanded mode can also possess such deteriorating effect due to the higher share of converter-based sources. In this paper, a coordinated frequency control within a distribution network is discussed, with a higher share of Photovoltaics (PV). The main objective of this paper is to test the grid-forming capabilities of PVs, without the requirement of an energy storage in the network. The tests were carried out with the help of the Typhoon Hardware-in-the-loop (HIL) platform using a real Cypriot network feeder. The real-time results confirm the efficacy of the PV as a grid-forming inverter, provided it has sufficient input (irradiance) to provide for the loads within the system of interest. The grid-forming PV also possesses the capability of reconnection with the utility grid through a synchronizer switch that requires minimal communication, makes the overall control independent of any other power source, subject to certain irradiance and loading conditions.Comment: 13th Mediterranean Conference on Power Generation, Transmission, Distribution and Energy Conversion (MEDPOWER 2022