Determination of quantum yields of photochemical transformations of 2-, 3- and 4-2[(2-vinylphenyl)ethenyl]pyridines

U cilju nastavka proučavanja utjecaja heterocikličke jezgre na fotokemijsko ponašanje supstituiranih o-divinilbenzena razvijena je sinteza novih supstituiranih o-divinilbenzena s piridinskom jezgrom. Wittigovom reakcijom sintetizirani su novi piridinski produkti 2-2[(2-vinilfenil)etenil]piridin (1), 3-2[(2-vinilfenil)etenil]piridin (2) i 4-2[(2-vinilfenil)etenil]piridin (3) kao smjese geometrijskih izomera. Iz smjesa izomera uspješno su izolirani cis- i trans-izomeri koristeći kolonsku i tankoslojnu kromatografiju te su isti u potpunosti spektroskopski opisani. Svi novi sintetizirani derivati 1-3 podvrgnuti su fotokemijskim reakcijama na 300 nm u uvjetima sa i bez kisika u smjeru priprave novih bicikličkih struktura. Početni spojevi pokazali su različito fotokemijsko ponašanje. Fotoreakcija spoja 1 dovodi do zatvaranja u ciklizacijski spoj 7-etenil-benzo[f]kinolin (6), a uz njega izolirana su i opisana i dva intermedijara 7-etenil-10aH,10bH-cikloheksa[f]kinolin (4) i 7-etenil-1H,4H-benzo[f]kinolin (5). Uz ciklizacijski produkt nastala su dva produkta reakcijama cikloadicije i to biciklički produkt 2-(triciklo[6.1.1.02,7]deka-2,4,6-trien-9-il)piridin (7) te 3-azatetraciklo-[7.6.1.02,7.010,15]heksadeka-4-6,10(15),11,13-pentaen (8). Osvjetljavanjem spoja 2 dolazi do stvaranja većinskog ciklizacijskog spoja 7-etenil-benzo[f]izokinolina (9) (60 %) i manjinskog ciklizacijskog spoja 7-etenil-benzo[h]kinolina (10) (20 %) te bicikličkog produkta 3-(triciklo[6.1.1.02,7]deka-2,4,6-trien-9-il)piridina (11) (8 %). Osvjetljavanjem spoja 3 pokazalo se kako on uopće ne reagira već isključivo dolazi do reakcije trans-cis izomerizacije. S ciljem upotpunjavanja našeg razumijevanja fotokemijskih procesa koji se odvijaju, izračunali smo kvantna iskorištenja korištenjem ferioksalatog aktinometra. Polazni spojevi 1-3 kao i njihovi fotoprodukti okarakterizirani su modernim spektroskopskim metodama (jednodimenzionalni i dvodimenzionalni NMR, UV, IR i MS). Novi potencijalni farmakološki interesantni spojevi dobiveni su jednostavnim pristupom koristeći svjetlo kao reagens i pogodni su za daljnje transformacije i funkcionalizacije.As a continuation of the study of the effect of the heterocyclic ring on the photochemical behavior of o-divinylbenzenes, a syntheses of new derivatives with pyridine as a heterocycle were developed. New derivatives 2-2[(2-vinylphenyl)ethenyl]pyridine (1), 3-2[(2-vinylphenyl)ethenyl]pyridine (2) and 4-2[(2-vinylphenyl)ethenyl]pyridine (3) were synthesized by Wittig reaction as mixtures of isomers. Both of the isomers, cis- and trans-, were isolated by chromatographic and thin layer chromatographies and completely spectroscopically analyzed. All of the derivatives 1-3 were irradiated at 300 nm to see if they would react and give new bicyclic products. Derivatives of 2-, 3- and 4-pyridine showed versatile reactivity in given conditions. Photoreaction of 2-pyridine derivative (1) gave, by cyclisation reaction, compound 7-vinylbenzo[f]quinoline (6). We were also able to isolate 2 intermediates of this process, compounds 7-vinyl-10a,10b-dihydrobenzo[f]quinoline (4) and 7-vinyl-1,4-dihydrobenzo[f]quinoline (5). This derivative also gave, by reaction of cycloaddition, two new bicyclic compounds, 2-(tricyclo[6.1.1.02,7]deca-2,4,6-trien-9-yl)pyridine (7) and 3-azatetracyclo[7.6.1.02,7.010,15]hexadeca-4-6,10(15),11,13-pentaene (8). Irradiation of compound 2 gave one major and a minor product. Major product was 7-vinylbenzo[f]isoquinoline (9) (60 %) and the minor 7-vinylbenzo[h]quinoline (10) (20 %). These derivatives also gave a cycloaddition product 3-(tricyclo[6.1.1.02,7]deca-2,4,6-trien-9-yl)pyridine (11) (8 %). Irradiation of 4-pyridine derivative in various conditions showed that this compound did not react in other than in reactions of photoisomerisation. To enrich our understanding of the photochemical process taking place we calculated quantum yields by utilization of ferrioxalate actinometer. All of the compounds were characterized by spectroscopic methods (one- and two-dimensional NMR, UV, IR and MS)

Determination of quantum yields of photochemical transformations of 2-, 3- and 4-2[(2-vinylphenyl)ethenyl]pyridines

U cilju nastavka proučavanja utjecaja heterocikličke jezgre na fotokemijsko ponašanje supstituiranih o-divinilbenzena razvijena je sinteza novih supstituiranih o-divinilbenzena s piridinskom jezgrom. Wittigovom reakcijom sintetizirani su novi piridinski produkti 2-2[(2-vinilfenil)etenil]piridin (1), 3-2[(2-vinilfenil)etenil]piridin (2) i 4-2[(2-vinilfenil)etenil]piridin (3) kao smjese geometrijskih izomera. Iz smjesa izomera uspješno su izolirani cis- i trans-izomeri koristeći kolonsku i tankoslojnu kromatografiju te su isti u potpunosti spektroskopski opisani. Svi novi sintetizirani derivati 1-3 podvrgnuti su fotokemijskim reakcijama na 300 nm u uvjetima sa i bez kisika u smjeru priprave novih bicikličkih struktura. Početni spojevi pokazali su različito fotokemijsko ponašanje. Fotoreakcija spoja 1 dovodi do zatvaranja u ciklizacijski spoj 7-etenil-benzo[f]kinolin (6), a uz njega izolirana su i opisana i dva intermedijara 7-etenil-10aH,10bH-cikloheksa[f]kinolin (4) i 7-etenil-1H,4H-benzo[f]kinolin (5). Uz ciklizacijski produkt nastala su dva produkta reakcijama cikloadicije i to biciklički produkt 2-(triciklo[6.1.1.02,7]deka-2,4,6-trien-9-il)piridin (7) te 3-azatetraciklo-[7.6.1.02,7.010,15]heksadeka-4-6,10(15),11,13-pentaen (8). Osvjetljavanjem spoja 2 dolazi do stvaranja većinskog ciklizacijskog spoja 7-etenil-benzo[f]izokinolina (9) (60 %) i manjinskog ciklizacijskog spoja 7-etenil-benzo[h]kinolina (10) (20 %) te bicikličkog produkta 3-(triciklo[6.1.1.02,7]deka-2,4,6-trien-9-il)piridina (11) (8 %). Osvjetljavanjem spoja 3 pokazalo se kako on uopće ne reagira već isključivo dolazi do reakcije trans-cis izomerizacije. S ciljem upotpunjavanja našeg razumijevanja fotokemijskih procesa koji se odvijaju, izračunali smo kvantna iskorištenja korištenjem ferioksalatog aktinometra. Polazni spojevi 1-3 kao i njihovi fotoprodukti okarakterizirani su modernim spektroskopskim metodama (jednodimenzionalni i dvodimenzionalni NMR, UV, IR i MS). Novi potencijalni farmakološki interesantni spojevi dobiveni su jednostavnim pristupom koristeći svjetlo kao reagens i pogodni su za daljnje transformacije i funkcionalizacije.As a continuation of the study of the effect of the heterocyclic ring on the photochemical behavior of o-divinylbenzenes, a syntheses of new derivatives with pyridine as a heterocycle were developed. New derivatives 2-2[(2-vinylphenyl)ethenyl]pyridine (1), 3-2[(2-vinylphenyl)ethenyl]pyridine (2) and 4-2[(2-vinylphenyl)ethenyl]pyridine (3) were synthesized by Wittig reaction as mixtures of isomers. Both of the isomers, cis- and trans-, were isolated by chromatographic and thin layer chromatographies and completely spectroscopically analyzed. All of the derivatives 1-3 were irradiated at 300 nm to see if they would react and give new bicyclic products. Derivatives of 2-, 3- and 4-pyridine showed versatile reactivity in given conditions. Photoreaction of 2-pyridine derivative (1) gave, by cyclisation reaction, compound 7-vinylbenzo[f]quinoline (6). We were also able to isolate 2 intermediates of this process, compounds 7-vinyl-10a,10b-dihydrobenzo[f]quinoline (4) and 7-vinyl-1,4-dihydrobenzo[f]quinoline (5). This derivative also gave, by reaction of cycloaddition, two new bicyclic compounds, 2-(tricyclo[6.1.1.02,7]deca-2,4,6-trien-9-yl)pyridine (7) and 3-azatetracyclo[7.6.1.02,7.010,15]hexadeca-4-6,10(15),11,13-pentaene (8). Irradiation of compound 2 gave one major and a minor product. Major product was 7-vinylbenzo[f]isoquinoline (9) (60 %) and the minor 7-vinylbenzo[h]quinoline (10) (20 %). These derivatives also gave a cycloaddition product 3-(tricyclo[6.1.1.02,7]deca-2,4,6-trien-9-yl)pyridine (11) (8 %). Irradiation of 4-pyridine derivative in various conditions showed that this compound did not react in other than in reactions of photoisomerisation. To enrich our understanding of the photochemical process taking place we calculated quantum yields by utilization of ferrioxalate actinometer. All of the compounds were characterized by spectroscopic methods (one- and two-dimensional NMR, UV, IR and MS)

Alkali salts of nitranilic and cyanochloranilic acids

Series of novel alkali salts of nitranilic acid (3, 6-dinitro-2, 5-dihydroxyquinone) and cyanochloranilic acid (3-cyano-6-chloro-2, 5-dihydroxyquinone), and also of neutral cyanochloranilic acid dihydrate, were prepared and their structures were studied. The nitranilate dianion revealed a considerable conformational flexibility of nitro groups. Steric and inductive effects exerted by different substituents (nitro, cyano and chloro) and their influence on molecular geometry and crystal packing are discussed

Učinak mikronizacije na sastav i svojstvo brašna dobivenog od bijelog, žutog i crvenog zrnja kukuruza

The process of micronisation, a short time high temperature process that utilizes electromagnetic radiation in the infrared region to rapidly heat materials, is often used to improve storage stability of whole grain flour. In this work the consequences of such temperature treatment on the quality and solubility of proteins, viscosity, content of total phenolics, tocopherols, ß-carotene, as well as the antioxidant properties of maize (Zea mays L.) flour are presented. For these studies three maize hybrids were used: the semi-flint hybrid ZP 633 with pronounced yellow kernels, ZP Rumenka with dark red pericarp and yellow endosperm, and ZP 551b hybrid which is characterized by white kernels. The process of micronisation did not change the content of crude protein, the amount of albumin, globulin and zein were decreased, while glutelin remained the same or increased after micronisation. As a consequence of thermal effect on maize protein, tryptophan content was significantly decreased. Micronisation had a significant effect on the pasting properties of the selected maize flour. Viscosity of all micronised flour samples increased constantly, but without reaching a peak during heating of the slurry to 95 °C. At 95 °C it was slightly higher, but final viscosity at 50 °C was significantly lower. The micronisation treatment decreased the content of bioactive compounds (tocopherols, ß-carotene) naturally present in the raw grains. The whole grain flour from micronised grain, with modified nutritional and technological characteristics, represents a good raw material for production of gluten-free products.Mikronizacija, tj. postupak kratkotrajnog izlaganja materijala visokoj temperaturi pomoću elektromagnetskoga zračenja u infracrvenom području, često se primjenjuje za poboljšanje stabilnosti pri skladištenju cjelovitoga brašna žitarica. U radu je ispitan utjecaj takva postupka na kakvoću i topljivost proteina, viskoznost, udio ukupnih fenola, tokoferola i β-karotena, te na antioksidativna svojstva kukuruznoga brašna. Upotrijebljena su tri hibrida kukuruza (Zea mays L.): ZP 633, polutvrdunac izrazito žutih zrna; ZP Rumenka, tamnocrvenoga perikarpa i endosperma žute boje, te ZP 551b bijelih zrna. Mikronizacija nije utjecala na udio sirovih proteina, ali je smanjila udio albumina, globulina i zeina, dok je udio glutelina ostao nepromijenjen ili se neznatno povećao. Nakon toplinske obrade udio se triptofana znatno smanjio. Mikronizacija je također uvelike utjecala na vezivna svojstva brašna. Povećana je viskoznost svih uzoraka brašna, ali nije dosegla vrhunac zagrijavanjem suspenzije do 95 ºC. Na 95 ºC viskoznost je bila nešto veća, dok je pri završetku mikronizacije na temperaturi od 55 °C bila kudikamo manja. Mikronizacijom se smanjio udio bioaktivnih spojeva (fenola, tokoferola i β-karotena) prisutnih u sirovom zrnju. Cjelovito brašno dobiveno mikronizacijom zrnja žitarica zbog svojih je hranjivih i tehnoloških svojstava dobra sirovina za dobivanje bezglutenskih proizvoda

Tehnologija prerade i korišćenje kukuruza - dostignuća i perspektive

Since its establishment the Maize Research Institute, Zemun Polje has been having an extremely important role in the improvement of maize production and utilisation. The aim of this manuscript is to present results of studies on chemical composition, physical and technological grain traits, i.e. utilisable value of the most widely grown ZP maize hybrids. Previous achievements and prospects of the development of chemistry and processing technology of maize grain as a highly valuable renewable raw material for industrial processing, different technical purposes and the food and feed production are presented. Results gained in many decades of studies show that maize hybrids developed at the Maize Research Institute, Zemun Polje are the unique initial material for the production of starch, bioethanol and highly-valuable food and feed, as well as a reliable sign-post for researchers performing maize breeding and selection in order to direct future studies within this field.Od svog osnivanja pa sve do danas, Institut za kukuruz 'Zemun Polje' imao je izuzetno važnu ulogu u unapređenju proizvodnje i korišćenja kukuruza. Uporedo sa ispitivanjem i ocenom kvaliteta hibrida kukuruza namenjenih proizvodnji zrna vrši se selekcija, ispitivanje i ocena silažnih formi kukuruza, odnosno ocena upotrebne vrednosti i kvaliteta kukuruzne biljke za ishranu životinja. Selekcionisani su hibridi kukuruza koji se na osnovu ispitivanih parametara kvaliteta zrna mogu svrstati u hibride visokog potencijala rodnosti, visokog tehnološkog i nutritivnog kvaliteta, konkurentni hibridima kukuruza domaćih i inostranih selekcionih kompanija. U našoj zemlji Institut za kukuruz 'Zemun Polje' je jedina naučna ustanova u kojoj se već više od pola veka sveobuhvatno radi na istraživanjima unapređenja tehnologije prerade i korišćenja kukuruza. U okviru ovog naučnoistraživačkog programa postignuti su izuzetno značajni rezultati, kao u retko kojoj naučnoj oblasti. Cilj ovog rada je bio da se prikažu rezultati ispitivanja hemijskog sastava, fizičkih i tehnoloških svojstava zrna, odnosno upotrebne vrednosti zrna najšire gajenih zemunpoljskih hibrida kukuruza. Opisana su dosadašnja dostignuća i perspektive budućeg razvoja hemije i tehnologije prerade zrna kukuruza kao visoko vredne prirodno obnovljive sirovine za industrijsku preradu, različite tehničke namene i proizvodnju raznovrsne hrane za ljude i životinje. Rezultati višedecenijskih istraživanja su pokazali da hibridi kukuruza stvoreni u Institutu za kukuruz 'Zemun Polje' predstavljaju jedinstven polazni materijal za proizvodnju skroba, bioetanola i visokovredne hrane za ljude i životinje, kao i pouzdani putokaz istraživačima koji se bave njegovom selekcijom, u kom pravcu usmeriti buduća istraživanja u ovoj oblasti

Upotrebna vrednost kukuruzne biljke (biomase) za silažu

According to the estimation of leading experts, the maize utilisation for the production of silage from the whole plant, wet ear and wet grain should be one of the most important forms of its application in animal nutrition. Maize a major forage crop, because the highest accumulation of solar energy per area unit is accomplished by maize production and ensiling. At the Maize Research Institute, Zemun Polje, selection, testing and evaluation of silage maize. The aim of this study was to draw attention to this extremely significant field of science and studies on the utilisation of the whole maize plant (biomass) in feeding of domestic animals, primarily ruminants. This paper presents and discusses previous results and achievements of long-term scientific researches on the improvement of maize plant utilisation in making good-quality silage not only in our country but also in the world.Prema procenama vodećih stručnjaka korišćenje kukuruza za proizvodnju silaže od cele biljke, vlažnog klipa i vlažnog zrna trebalo bi da bude jedan od značajnijih oblika njegove primene u ishrani životinja. Kukuruz je najvažnija krmna biljka jer se njenom proizvodnjom i siliranjem postiže najviša akumulacija sunčeve energije po jedinici površine. U Institutu za kukuruz 'Zemun Polje' paralelno sa ispitivanjem i ocenom kvaliteta hibrida kukuruza namenjenih proizvodnji zrna vrši se selekcija, ispitivanje i ocena i silažnih formi kukuruza, odnosno upotrebne vrednosti i kvaliteta kukuruzne biljke za ishranu životinja. Kao rezultat ovog naučnoistraživačkog rada poslednjih nekoliko decenija selekcionisani su hibridi kukuruza koji su na osnovu ispitivanih parametara kvaliteta za silažne forme kukuruza visokog kvalitete. Karakteriše ih: visok prinos ukupne suve i ukupne svarljive suve materije po hektaru, visoko učešće suve materije klipa u ukupnom prinosu suve materije i visoka svarljivost suve materije cele biljke kukuruza. Cilj ovog rada bio je da se skrene pažnja na ovu izuzetno značajnu oblast nauke i istraživanja upotrebe cele kukuruzne biljke (biomase) u ishrani domaćih životinja, prvenstveno preživara. Prikazani su i diskutovani dosadašnji rezultati i dostignuća višegodišnjeg naučnoistraživačkog rada na unapređenju korišćenja kukuruzne biljke za spremanje kvalitetne silaže u našoj zemlji kao i u svetu. Opisan je kukuruz kao sirovina za proizvodnju i spremanje silaže od cele kukuruzne biljke kao kvalitetne kabaste hrane za ishranu domaćih životinja

EXPERIMENTAL AND NUMERICAL IDENTIFICATION OF STRUCTURAL MODES FOR ENGINEERING EDUCATION

Abstract. Development of simple classroom demonstration device and software for visualization of structural normal modes is presented. Device is made of parts of old speaker, controlled with personal computer, where the harmonic motion of solenoid is used as an excitation for beam and plate models. Simple code for finite element free vibration analysis of plates is written in Wolfram Mathematica. Good agreement of results and attractive visual patterns of normal modes attracted attention of students. Results are confirmed using modern modal testing methods. Presented approach is complementary to standard teaching of structural dynamics. Key words: engineering education, normal modes, Chladni plate, modal testing, finite element metho

Prinos i kvalitet biomase cele biljke četiri hibrida kukuruza za proizvodnju silaže

This paper presents the results of a study on the yields of green matter, dry matter and digestible dry matter of the whole plant of four ZP silage maize hybrids (gown in four different locations in the Republic of Serbia) and the quality of their whole-plant biomass. The results obtained indicate that the highest average yields of green matter (40.4 t·ha-1), dry matter (14.4 t·ha-1) and digestible dry matter of the whole plant (8.8 t·ha-1) were recorded in the ZP 707 hybrid at all four locations considered. The highest average content of lignocellulosic fibres was detected in the ZP 735 hybrid, which also exhibited the lowest dry matter digestibility of the whole plant (57.24%). The highest average digestibility of dry matter (61.00%) and NDF (NDFD - Neutral Detergent FibresDigestibility) (26.20%) of the whole maize plant was determined in the ZP 707 hybrid, which also had the lowest average content of all lignocellulosic fibres.Kukuruz je najvažnija krmna biljka po visini prinosa i kvalitetu biomase. Najvažniji parametri kvaliteta silažnih formi hibrida kukuruza su: prinos ukupne i svarljive suve materije, sadržaj i odnosi lignoceluloznih vlakana (NDF – vlakna nerastvorna u neutralnom deterdžentu, ADF – vlakna nerastvorna u kiselom deterdžentu i ADL – lignin nerastvorljiv u 72% rastvoru sumporne kiseline), svarljivost suve materije i svarljivost NDF (NDFD) cele biljke kukuruza. Svarljivost suve materije i NDFD daju preciznije podatke o kvalitetu biomase kukuruzne biljke za silažu. U ovom radu su prikazani rezultati istraživanja prinosa zelene mase, suve materije i svarljive suve materije, kao i kvalitetabiomase (sadržaj i odnosi lignoceluloznih vlakana, svarljivost suve materije i NDF) cele biljke četiri silažna ZP hibrida kukuruza gajenih na četiri različite lokacije u Republici Srbiji. Rezultati su pokazali da se prosečan sadržaj suve materije cele biljke kretao od 28,03% (ZP 735) do 35,84% (ZP 707).Najviši prosečan prinos zelene mase od 40,4 t∙ha-1, suve materije od 14,4 t·ha-1 i prinos svarljive suve materije cele kukuruzne biljke za sve četiri lokacija od 8,8 t∙ha-1 imao je hibrid ZP 707. Najviši prosečan sadržaj lignoceluloznih vlakana (NDF, ADF, hemiceluloze i celuloze) imao je hibrid ZP 735 koji je imao najnižu svarljivost suve materije cele kukuruzne biljke (57,24%). Najvišu prosečnu svarljivost suve materije (61,00%) i NDFD (26,20%) cele kukuruzne biljke imao je hibrid ZP 707 koji je imao i najniži prosečan sadržaj svih lignoceluloznih vlakana: NDF (52,85%), ADF (26,11%), ADL (3,31%), hemiceluloze (26,74%) i celuloze (22,80%)