Jakov M. Ovadia - chess fanatic

U istorijatu beogradskog šaha i šaha u Srbiji u celini, ne može a da se ne pomene Jakova M. Ovadije. Dopisni, problemski i turnirski šah u Srbiji u začetku su duboko vezani za uglednog beogradskog advokata Žaka - Jakova M. Ovadiju. Osim toga, Jakov M. Ovadija se smatra prvim šahovskim novinarom u Srbiji, i jednim od najupornijih i najdoslednijih promotera ove čudesne drevne igre kod nas u prvoj polovini 20. veka. Ono što je Jakov M. Ovadija učinio za afirmaciju šaha u Beogradu nije dovoljno dokumentovano niti u potpunosti vrednovano. Retki znaju da je Jakov M. Ovadija bio jedan od potpisnika za osnivanje Međunarodne šahovske organizacije - FIDE, u Parizu 1924. godine. U svoje vreme je u Beograd i okolinu, dovodio najpoznatije šahiste sveta, među kojima i aktuelnog svetskog prvaka Aleksandra Aljehina, kao i bivšeg šampiona sveta dr Emanuela Laskera. Ova saznanja i još mnogo toga povodi su da se kompletnije osvetli život, pre svega šahovski, ovog neponovljivog šahovskog fanatika.In the history of Belgrade chess and chess in Serbia, it is impossible not to mention Jakov M. Ovadija. In the beginning, correspondence, problems and tournament chess in Serbia were deeply connected to the distinguished Belgrade lawyer Žak - Jakov M. Ovadija. In addition, Jakov M. Ovadia is considered the first Serbian chess journalist, and one of the most persistent and consistent promoters of this marvellous ancient game in our country in the first half of the 20th century. What Jakov M. Ovadija did for the affirmation of chess in Belgrade is not sufficiently documented or completely evaluated. Few people know that Jakov M. Ovadija was one of the signatories to the founding of the International Chess Organization - FIDA, in Paris in 1924. In his time, he brought the world's most famous chess players to Belgrade and its surroundings, including the current world champion Alexander Alekhine, as well as former world champion Dr Emanuel Lasker. These findings and many more are the reasons to shed more light on the life, primarily chess, of this inimitable chess fanatic.Ovaj rad je 2008. godine na 52. nagradnom konkursu Saveza jevrejskih opština Srbije, dobio nagradu Otkup (In 2008, at the 52nd award competition of the Federation of Jewish Communities of Serbia, this novel received the buyout award)

Pogrom of Jews in Stara Pazova in 1942 - "Black May Night"

Zbornik „Sremsko krvavo leto 1942“ (Dušan Lazić-Gojko: „Sremske novine“ 1982) dokumentuje podatke o stradanju Sremaca tokom 1942. godine, od dolaska ustaškog kapetana, potpukovnika Viktora Tomića u Srem na kraju avgusta 1942. Knjiga ne obuhvata ustaške ratne zločine počinjene pre dolaska Vikotora Tomića u Srem. Tako nije zabeležen ni slučaj hapšenja jevrejskog stanovnika u Staroj Pazovi početkom maja 1942. godine. Razlog zbog kojeg su svi ljudi u Sremu streljani vidi se u saopštenju Ustaškog Prečkog mobilnog suda od 8. avgusta 1942. koji je zasedao u Staroj Pazovi i osudio streljanje 18 stanovnika Stare Pazove. i Novi Karlovac“... S druge strane, oko 50 staropazovačkih Jevreja okupirano je bez optužbe, suđenja i dokaza za bilo kakav zločin od okupatorsko-kvislinške folksdojčerske vlasti i oterano da nestane i ne zna se gde su završili njihove živote. O njima nema beleški u zvaničnim postojećim dokumentima Saveza jevrejskih opština. Ovo je priča o stradanju staropazovačkih Jevreja na osnovu dostupnih dokumenata od kojih je u ovoj ostalo samo groblje predaka mesto, koje godinama po verskom običaju niko ne održava.The collection "Sremsko krvavo leto 1942" (Dušan Lazić-Gojko: "Sremske novine",1982) documents the data on the suffering of the people of Srem during 1942, since the coming of Ustasha captain, lieutenant colonel Viktor Tomić in Srem at the end of August 1942. The book does not include Ustasha's war crimes done before the coming of Vikotor Tomić in Srem. Thus, the case of the arrest of a Jewish resident in Stara Pazova in early May 1942 was not recorded either. The reason why all the people in Srem were shot can be seen in the announcement of the Ustasha Prečki mobilni sud (mobile court) dated August 8, 1942, which was in session in Stara Pazova and condemned the shooting of 18 inhabitants from Stara Pazova and Novi Karlovac"... On the other hand, about 50 Jews from Stara Pazova were rounded up without accusation, trial or proof of any crime by the occupying-Quisling Volksdeutsche authorities, and driven to disappear and it is not known where they ended their lives. There are no notes about them in the official existing documents of the Federation of Jewish Communities. This is the story of the suffering of the Jews from Stara Pazova, based on the available documents, of which only the ancestral cemetery remains in this place, which has been maintained for years by no one according to religious custom.Na 66. nagradnom konkursu Saveza jevrejskih opština Srbije, za 2022. godinu, rad je nagrađen otkupom (this work was awarded at the 66th prize competition of the Federation of Jewish Communities of Serbia for 2022)

The review of some novel biomarkers in sedimentary organic matter

A series of novel C33-C35 hexacyclic benzohopanes have been identified in coals and crude oils of different ages from all over the world [1]. They differ from regular benzohopanes by the presence of methyl group in position C-31. These compounds are more abundant in coals and terrestrial oils. The investigation also showed that mature samples have distributions of benzohopanes distinct from immature ones, which are characterised by a greater number of benzohopane isomers. Although exact structures of the additional isomers were not determined, it seems they were formed by an isomerisation of alkyl groups attached to the aromatic ring. Two novel monoaromatic hydrocarbons (MW = 270; basic fragment ions m/z 255 and 146) were identified in coals, mudstones and crude oils. Their structures were determined as cis- and transicetexa-8,11,13-trienes (or dehydroicetexanes) using NMR spectroscopy. Dehydroicetexanes are potential biomarkers of Cupressaceae (cypress conifers). Benzo[b]naphtho[d]furans (BNFs) have been identified in oils, condensates, source-rocks, coals and coaly shales, being more abundant in the latter. We detected BNFs (m/z 218) in relatively high amounts in the aromatic fractions of pyrolysates of brown coals which attained the maturity corresponding to vitrinite reflectance of 1.80 %Rr [2]. This result suggests that BNFs can be attractive for investigations of mature fluids that originate from gas/condensate prone sources, rich in type III kerogen, which are usually depleted in biomarkers. Recently, it was observed that [2,1]/[1,2]BNF ratio can be used to describe lithofacies [3]. This ratio is much lower in sediments from fluvial-deltaic systems than in clay-depleted sediments from marine environments. 1-Chloro-n-alkanes (m/z 91) have been identified in saltmarsh vegetation, recent sediments from estuarine setting and freshwater lake sediments [4]. Despite their absence in the investigated crude oils, we identified a series of 1-chloro-n-alkanes in pyrolysates of the corresponding asphaltenes, obtained at 250 oC. This result indicates very good preservation of biomarkers occluded inside asphaltenes and announces a possible application of 1-chloro-n-alkanes in correlation studies.Invited Lectur

Effect of Gd3+ introduction on YF3: Yb, Er structural, morphological and optical properties

Monosized up-converting nanoparticles (UCNPs) with a spherical shape and biocompatible surface have a wide application in biomedicine as new cell markers or light-triggered drug delivery agents. The synthesis of the hexagonal β-NaYF4:Yb/Er phase is of a great interest, because of its most efficient up-conversion luminescence. Beside it, synthesis of the UCNPs based on YF3:Yb/Er phase is also attractive due to its orthorhombic phase arrangement and fact that higher concentration of dopants could be introduced in such crystal lattice. In this work the synthesis of pure and Gd-doped YF3:Yb/Er phases were performed through hydro/solvo thermal method using a biocompatible chitosan as a surfactant. The XRD analysis showed that independently of the gadolinium content formation of the orthorhombic phase is achieved, but intensity of the green emission due to the (2H11/2, 4S3/2) → 4I15/2 electronic transitions was highest for un-doped YF3:Yb/Er sample

Citrate assisted solvothermal synthesis of beta-NaYF4: Yb, Er up-converting nanoparticles

Thanks to the unique optical properties, up-converting nanoparticles (UCNPs) have a wide application in optoelectronics, forensics, security and biomedicine. The synthesis of the most efficient hexagonal β-NaYF4: Yb/Er phase is usually performed through thermal decomposition of organic precursors which could cause the UCNP cytotoxicity. Since cubic polymorph is kinetically more stable than hexagonal, we used citric acid and Na-citrate for the nucleation of hexagonal NaYF4: Yb, Er phase in nanosized particles. Additionally, effect of different precipitation agents (NaF, NH4F and NH4HF2) used during solvothermal synthesis is explored. The XRPD analysis showed that using of citric acid led to a product composed from mixture of cubic and hexagonal NaYF4: Yb/Er phase, while the presence of Na-citrate influences the nucleation of well crystallized hexagonal β-NaYF4: Yb/Er phase, regardless of precipitation agents used. All samples are composed of polycrystalline spherical particles which size is influenced by the precursor chemistry. UCNPs emit intense green emission due to the (2H11/2, 4S3/2) → 4I15/2 electronic transitions, after been excited with infrared light (λ=978 nm)

Polyacrilic Acid and Chitosan Assisted Solvothermal Synthesis of Up-converting NaYF4: Yb,Er Particles

There is a growing interest for development of a facile and reproducible approach for the synthesis of biocompatible lanthanide doped up-converting nanoparticles (UCNPs) for deep tissue imaging and targeted drug delivery. Synthesis of such particles is usually performed through the decomposition of organometallic compounds, followed either with a ligands exchange or with a biocompatible layer coating. In this work, biocompatible NaYF4:Yb,Er (17 mol% Yb; 3 mol% Er) nanoparticles were synthesized by one-pot hydrothermal processing with an assistance of chitosan (Ch) or polyacrylic acid (PAA). Obtained powders were analyzed by X-ray powder diffraction (XRPD, Bruker D8 Discovery), field emission scanning electron microscopy (FE-SEM, Zeiss, DSM 960), transmission electron microscopy (TEM, JEOL JEM 2010), Fourier transform infrared (FTIR, Thermo Scientific Nicolet 6700) and photoluminescence (PL, Spex Fluorolog with C31034 cooled photomultiplier) spectroscopy. The results showed that although both powders crystallize in the same crystal arrangement (cubic, Fm-3m), particles size, shape and optical properties are dependent on the polymer used

The usage of different fluoride sources during solvothermal synthesis of UCNPs in hydroxyl-carboxyl chelated precursor

There is a great interest for the synthesis of rare earth (RE) doped up-converting nanoparticles (UCNPs) which morphological and luminescence properties are well suited for application in optoelectronics, forensics, security and biomedicine. The synthesis of such particles usually comprises decomposition of organometallic compounds in an oxygen-free environment followed with coating of biocompatible layer or ligands exchange. In this work hydroxyl-carboxyl (HO-C) type of chelators (citric acid and sodium citrate) are used for the stabilization of NaYF4:Gd,Yb,Er UCNPs during solvothermal treatment of rare earth nitrate salts with different fluoride sources (NaF, NH4F and NH4HF2). The x-ray powder diffraction (XRPD) showed that all powders contain the mixture of cubic and hexagonal NaYF4:Gd,Yb,Er phase in nano and micro-sized particles respectively. However, the content of later one prevails in samples obtain when Nacitrate is used as chelator, regardless of which fluoride source is used for precipitation. Additionally, variation of the particles size and shape is detected with a variation of fluoride type. All particles have hydrophilic surface due to retention of citrate ligands and emit intense green light emission centered at 519 and 539 nm (2H11/2,4S3/2→4I15/2) when excited with near infrared light

Polyacrilic Acid and Chitosan Assisted Solvothermal Synthesis of Up-converting NaYF4: Yb,Er Particles

There is a growing interest for development of a facile and reproducible approach for the synthesis of biocompatible lanthanide doped up-converting nanoparticles (UCNPs) for deep tissue imaging and targeted drug delivery. Synthesis of such particles is usually performed through the decomposition of organometallic compounds, followed either with a ligands exchange or with a biocompatible layer coating. In this work, biocompatible NaYF4:Yb,Er (17 mol% Yb; 3 mol% Er) nanoparticles were synthesized by one-pot hydrothermal processing with an assistance of chitosan (Ch) or polyacrylic acid (PAA). Obtained powders were analyzed by X-ray powder diffraction (XRPD, Bruker D8 Discovery), field emission scanning electron microscopy (FE-SEM, Zeiss, DSM 960), transmission electron microscopy (TEM, JEOL JEM 2010), Fourier transform infrared (FTIR, Thermo Scientific Nicolet 6700) and photoluminescence (PL, Spex Fluorolog with C31034 cooled photomultiplier) spectroscopy. The results showed that although both powders crystallize in the same crystal arrangement (cubic, Fm-3m), particles size, shape and optical properties are dependent on the polymer used

Polyacrilic Acid and Chitosan Assisted Solvothermal Synthesis of Up-converting NaYF4: Yb,Er Particles

There is a growing interest for development of a facile and reproducible approach for the synthesis of biocompatible lanthanide doped up-converting nanoparticles (UCNPs) for deep tissue imaging and targeted drug delivery. Synthesis of such particles is usually performed through the decomposition of organometallic compounds, followed either with a ligands exchange or with a biocompatible layer coating. In this work, biocompatible NaYF4:Yb,Er (17 mol% Yb; 3 mol% Er) nanoparticles were synthesized by one-pot hydrothermal processing with an assistance of chitosan (Ch) or polyacrylic acid (PAA). Obtained powders were analyzed by X-ray powder diffraction (XRPD, Bruker D8 Discovery), field emission scanning electron microscopy (FE-SEM, Zeiss, DSM 960), transmission electron microscopy (TEM, JEOL JEM 2010), Fourier transform infrared (FTIR, Thermo Scientific Nicolet 6700) and photoluminescence (PL, Spex Fluorolog with C31034 cooled photomultiplier) spectroscopy. The results showed that although both powders crystallize in the same crystal arrangement (cubic, Fm-3m), particles size, shape and optical properties are dependent on the polymer used