Search

We report a measurement of the amplitude ratio $r_S$ of $B^0 to D^0K^{ast 0}$ and $B^0 to bar {D^0}K^{ast 0}$ decays with a Dalitz analysis of $Dto K_S^0pi ^+pi ^-$ decays, for the first time using a model-independent method. We set an upper limit $r_S < 0.87$ at the 68% confidence level, using the full data sample of $711,{rm fb}^{-1}$ corresponding to $772times 10^6$ $Bbar {B}$ pairs collected at the $Upsilon (4S)$ resonance with the Belle detector at the KEKB $e^+e^-$ collider. This result is obtained from observables $x_- = +0.4 ^{+1.0 +0.0}_{-0.6 -0.1} pm 0.0$, $y_- = -0.6 ^{+0.8 +0.1}_{-1.0 -0.0} pm 0.1$, $x_+ = +0.1 ^{+0.7 +0.0}_{-0.4 -0.1} pm 0.1$, and $y_+ = +0.3 ^{+0.5 +0.0}_{-0.8 -0.1} pm 0.1$, where $x_pm = r_S cos (delta _S pm phi _3)$, $y_pm = r_S sin (delta _S pm phi _3)$, and $phi _3 (delta _S)$ is the weak (strong) phase difference between $B^0 to D^0K^{ast 0}$ and $B^0 to bar {D^0}K^{ast 0}$.

We report an improved measurement of $D^0–{overline{D}}^0$ mixing and a search for $CP$ violation in $D^0$ decays to $CP$ -even final states $K^+K^−$ and $pi^+pi^-$. The measurement is based on the final Belle data sample of $976 fb^{−1}$. The results are $y_CP=(1.11±0.22±0.09)%$ and $A_Γ=(−0.03±0.20±0.07)%$, where the first uncertainty is statistical and the second is systematic.

Zaščita lesa je, kljub poostrenim okoljevarstvenim zahtevam, še vedno nujno potrebna in ekonomsko upravičena. Zaradi dobrih fungicidnih lastnosti se za impregnacijo lesa množično uporablja tudi bakrove spojine. Ker se dokaj slabo vežejo v les, se iz njega izpirajo. V kombinaciji s kromom pa se baker v lesu dobro fiksira. V zadnjem času so v mnogih državah omejili uporabo kromovih soli, oziroma jih nameravajo prepovedati. Strokovnjaki zato za fiksacijo bakra iščejo druge spojine. Kot primerni in potencialno uporabni so se izkazaliamini. Raziskovali smo interakcije med bakrovimi pripravki z etanolaminom (C2H7NO, 2-aminoetanol) in komponentami lesa. Opazili smo, da etanolamin z lesom reagira. Z metodo nihajne spektroskopije (FTIR) smo opazilispremembe na skupinah lignina in polioz. Razvili smo tudi metodo, kjer reagent z barvno reakcijo dokaže prisotnost etanolamina v lesu. Wood preservation is necessary and is economically important. Copper compoundsare used for wood preservation because of their good fungicidal properties. Since copper compounds do not fix into wood, they can leach out of it. A presence of chromium prevents leaching of copper from wood. Recently, many countries intend to bound or limit the use of chromium salts. Therefore, experts looking for other suitable compounds to fix copper and amines seem to be suitable substitutes for chromium. We report about our investigations of interactions between copper(II) octanoate and ethanolamine (C2H7NO, 2-aminoethanole) and wood or its components. We found out that ethanolamine chemically reacts with wood. With the FTIR method, we noticed changes on groups belonging to lignin or hemicelluloses. We developed an indicator for spot-tests spot-tests of ethanolamine in wood.

We report a search for B decays to selected final states with the ηc meson: B± → K±ηcπ+π−, B± → K±ηcω, B± → K±ηcη and B± → K±ηcπ0. The analysis is based on 772 × 10^6 B¯B pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. We set 90% confidence level upper limits on the branching fractions of the studied B decay modes, independent of intermediate resonances, in the range (0.6–5.3)×10^−4. We also search for molecular-state candidates in the D^0 ¯D^∗0 − ¯D^0D^∗0, D^0 ¯D^0 + ¯D^0D^0 and D^∗0¯D^∗0 + ¯D^∗0D^∗0 combinations, neutral partners of the Z(3900)± and Z(4020)±, and a poorly understood state X(3915) as possible intermediate states in the decay chain, and set 90% confidence level upper limits on the product of branching fractions to the mentioned intermediate states and decay branching fractions of these states in the range (0.6–6.9)×10^−5.

We present a measurement of the time-dependent CP violation parameters in B0 → η′K0 decays. The measurement is based on the full data sample containing 772 × 10^6 BB pairs collected at the Υ(4S) resonance using the Belle detector at the KEKB asymmetric-energy e+e− collider. The measured values of the mixing-induced and direct CP violation parameters are: sin⁡ 2ϕ1eff=+0.68±0.07±0.03, Aη′K0=+0.03±0.05±0.04, where the first uncertainty is statistical and the second is systematic. The values obtained are the most accurate to date. Furthermore, these results are consistent with our previous measurements and with the world-average value of sin 2ϕ1 measured in B0 → J/ψK0 decays.

Microwaves are very effective at wood pest eradication. However, elevated temperatures may pose a risk of damaging surface coatings used on cultural and historical artefacts. Therefore, we monitored changes in patterns of the original paint taken from such objects along with newly prepared coatings. We evaluated visual, mechanical, and chemical modifications of coatings when exposed to microwaves (750W, 2.4GHz), at 60°C or 80°C for 10 min. Whether old or new, only water-based coatings have proven to be resistant to elevated temperatures and no damage was observed at 80°C. Blisters have formed on layers of new oil paints and natural resins due to insufficiently cured film. Temperatures above 80°C may cause melting of coniferous wood resin and thus transport of resin to the surface; on the other hand, temperatures up to 60°C are completely harmless. Mechanical and chemical changes of coatings exposed to microwaves were not observed, but the studies showed that colour and gloss exhibited minor changes. Mikrovalovi so zelo učinkoviti pri zatiranju lesnih škodljivcev. Lahko pa povišane temperature pomenijo tveganje za nastanek poškodb površinskih premazov, uporabljenih na kulturnozgodovinskih predmetih. Zato smo spremembe spremljali na vzorcih originalnih premazov, odvzetih s kulturnozgodovinskih predmetov, ter na novo pripravljenih premazih. Ocenili smo vizualne, mehanske in kemične spremembe premazov, izpostavljenih mikrovalovom (750W, 2,4 GHz) pri 60 °C ali 80 °C za 10 min. Stari premazi in novi, a le tisti na vodni osnovi, so se izkazali odpornejši proti povišanim temperaturam in poškodb pri 80 °C nismo opazili. Poškodbe v obliki mehurjenja so nastajale pri slojih nove oljne barve in naravnih smol, kot posledica premalo utrjenega filma. Temperatura nad 80 °C lahko povzroči taljenje smole v lesu iglavcev in tako prodiranje na površino vzorca pod premaz, medtem ko so temperature do 60 °C povsem neškodljive. Mehanskih in kemičnih sprememb premazov, izpostavljenih mikrovalovom, raziskave niso pokazale, sta pa se minimalno spremenila barva in sijaj.

Za zunanjo uporabo se v svetu namesto naravnega lesa uvaja uporaba modificiranega lesa, ki je dimenzijsko stabilnejši. V literaturi pa je še vedno zelo malo podatkov o sistemih modificiran les - površinski premaz. Zato je bil cilj naše raziskave preučiti lastnosti premazov za zunanjo uporabo na termično modificiranem lesu rdečega bora in nekaterih drugih lesnih substratih. Izvedli smo umetno pospešeno staranje nepremazanih in premazanih vzorcev ter ugotavljali vplive tega postopka na lastnosti, kot so oprijemnost premaza, barva, sijaj, kontaktni kot za vodo ter prepustnost premaza za vodno paro in tekočo vodo. Ugotovili smo, da je sistem "termično modificiran rdeči bor - premaz" primerljiv s sistemom "nemodificiran les - premaz". Due to its increased dimensional stability, modified wood is suited for outside applications. Because the systems "exterior surface coatings - modified wood" have not been studied thoroughly up to now, the aim of our workwas to investigate some properties of exterior finishes on thermally modified pine wood and on some other wooden substrates. We carried out artificial accelerated aging of unpainted and painted samples and considered the influence of aging procedure on some properties of the coatings like adhesion, colour, gloss, wettability and water-vapour and liquid water permeability. The results showed that the system "thermally modified pine wood- surface coating" is comparable to conventional systems "non-modified wood - surface coating".

V diplomski nalogi je obravnavana tema evtanazije in asistence pri samomoru. Podan je opis posameznih pravnih ureditev nekaterih držav v evropi in ZDA. Le travail de diplôme concerne les thèmes de l'euthanasie et l'assistance au suicide. Les cadres juridiques des certaines pays europeens sont traite ainsi que des Etats-unis.

V prispevku so predstavljene osnovne značilnosti voskov in njihova delitev. Podane so lastnosti in uporaba voskov, ki se pogosto pojavljajo v lesarstvu (čebelji, karnauba, montanski, šelakov, parafinski in sintetični voski). Glavna lastnost voskov, ki jo v lesarstvu izkoriščamo, je njihova vodoodbojnost. Obdelava lesa z vodoodbojnimi sredstvi je v praksi zelo pogosta in se uporablja za zaščito pred navzemom tekoče vode ter za preprečevanje razvoja in rasti gliv. Najpogosteje se v ta namen uporablja parafinski vosek z dodatkom smol in biocidov. Vosek se na površini ne utrjuje kemijsko ampak se v lesno strukturo veže s šibkimi Van der Waalsovimi vezmi. To je vzrok, da voskana površina sčasoma izgublja vodoodbojni učinek. Basic characteristics of waxes and their classification are described in this contribution. Furthermore, basic prop- erties and potential uses of the most important waxes (bee, carnauba, montan, shellac, paraffin and synthetic wax) are described. These waxes are used in wood industry predominately due to their water repellency. Use of water repellents in wood industry is rather frequent procedure in order to limit water penetration and to prevent fungal infestation. Paraffin wax in combination with biocides and resins is the most commonly used for this purpose. However, waxes do not form chemical bonds with wood, but there are only weak Van der Waals bonds formed. This is the main reason for the fact, that wax treated surfaces lose hydrophobic properties within time.

Po postopku luženja z vodnim lužilom so v lesnoobdelovalnem podjetju naleteli na problem različnega nabreka posameznih letvic znotraj lepljenega elementa. Zaradi tega smo obstoječe lužilo poskušali modificirati na ta način, da bi zmanjšali njegovo penetracijo v les. Pripravili smo 15 novih formulacij, še pred tem pa smo morali razviti hitro, enostavno in zanesljivo metodo za določanje globine penetracije lužila v les. Ugotovili smo, da so štirje novi pripravki penetrirali signifikantno manj od izvornega vodnega lužila. Le-te bomo preskusili tudi v industrijskem merilu. Dobljene razlike v globini penetracije preskušenih pripravkov so izkazale, da je novo razvita metoda zanesljiva. Kljub temu pa jo bomo v naših nadaljnjih raziskavah poskušali izboljšati. Prav tako bomo proučili vpliv vlažnosti lesa pred luženjem na globino penetracije lužila. During the staining a company, producing wood furniture, encountered a problemof uneven swelling of small boards in glued elements. Therefore we tried to modify the used stain in the way that it would penetrate less into wood. We prepared 15 modified formulations of the waterborne stain, but firstly, we had to develop a simple, quick and reliable method for determination of the stain penetration into the wood. We have found that four modified waterborne stain formulations penetrated significantly less than the original one. Their performance on the industrial scale will be evaluated by further tests. The observed differences between penetration depths of the tested formulations proved that the new method is reliable. However, in order to improve the method, some further investigations will be carried out. We also intend to investigate the influence of wood moisture content on the penetration of the stain.

Due to its increased dimensional stability, modified wood is suited for outside applications. Because the systems "exterior surface coatings - modified wood" have not been studied thoroughly up to now, the aim of our workwas to investigate some properties of exterior finishes on thermally modified pine wood and on some other wooden substrates. We carried out artificial accelerated aging of unpainted and painted samples and considered the influence of aging procedure on some properties of the coatings like adhesion, colour, gloss, wettability and water-vapour and liquid water permeability. The results showed that the system "thermally modified pine wood- surface coating" is comparable to conventional systems "non-modified wood - surface coating".

The massive wood and plywood samples of African mahogany (Khaya sp.) were exposed to various illumination conditions. The largest changes of colour were exhibited after irradiation with UV light. As stated by FT-IR spectroscopy, exposure to UV light caused chemical changes of lignin and hemicellulose. In order to decrease the problem of fast discolourations of boat interior furniture elements, made of mahogany wood, already during production process, we tested preventive effectiveness of 17 different alkyd or acrylic polyurethane (PU) coatings. It was found out, that high sensitivity of PU coatings and PU finished mahogany plywood could be diminished by selection of appropriate UV-protecting additives. Although the protective coatings after application changed the colour of mahogany wood substantially, this remained relatively stable afterwards. Therefore, annoying discolorations of furniture made of mahogany wood do not appear during utilisation. Vzorce iz masivnega lesa in vezane plošče lesa afriškega mahagonija (Khaya sp.) smo izpostavili različnim svetlobnim pogojem. Največje spremembe barve so se pojavile po obsevanju z UV svetlobo, ki povzroča kemijske spremembe lignina in tudi hemiceluloze kar smo ugotovili iz nihajnih (FT-IR) spektrov. Da bi omilili hitre diskoloracije notranje opreme plovil iz mahagonijevega lesa, do katerih prihaja že med proizvodnjo, smo preverili zaščitno učinkovitost sedemnajstih različnih poliuretanskih premaznih sistemov na alkidni in akrilni osnovi. Ugotovili smo, da je visoko barvno občutljivost poliuretanskih premazov in premazanega mahagonijevega lesa možno bistveno izboljšati z izbiro primernih dodatkov, ki premaz in les ščitijo pred UV žarki. Premazni sistem sicer močno spremeni barvo mehansko obdelanega mahagonijevega lesa, vendar pa se nato barva med procesom proizvodnje in uporabe bistveno ne spreminja več, tako da barvni madeži ne nastajajo, morebitne naknadne manjše barvne spremembe pa za uporabnike niso moteče.

Wood preservation is necessary and is economically important. Copper compoundsare used for wood preservation because of their good fungicidal properties. Since copper compounds do not fix into wood, they can leach out ofit. A presence of chromium prevents leaching of copper from wood. Recently, many countries intend to bound or limit the use of chromium salts. Therefore, experts looking for other suitable compounds to fix copper and amines seem to be suitable substitutes for chromium. We report about our investigations of interactions between copper(II) octanoate and ethanolamine (C2H7NO, 2-aminoethanole) and wood or its components. We found out that ethanolamine chemically reacts with wood. With the FTIR method, we noticed changes on groups belonging to lignin or hemicelluloses. We developed an indicator for spot-tests spot-tests of ethanolamine in wood.

Wood preservation is necessary and is economically important. Copper compoundsare used for wood preservation because of their good fungicidal properties. Since copper compounds do not fix into wood, they can leach out of it. A presence of chromium prevents leaching of copper from wood. Recently, many countries intend to bound or limit the use of chromium salts. Therefore, experts looking for other suitable compounds to fix copper and amines seem to be suitable substitutes for chromium. We report about our investigations of interactions between copper(II) octanoate and ethanolamine (C2H7NO, 2-aminoethanole) and wood or its components. We found out that ethanolamine chemically reacts with wood. With the FTIR method, we noticed changes on groups belonging to lignin or hemicelluloses. We developed an indicator for spot-tests spot-tests of ethanolamine in wood. Zaščita lesa je, kljub poostrenim okoljevarstvenim zahtevam, še vedno nujno potrebna in ekonomsko upravičena. Zaradi dobrih fungicidnih lastnosti se za impregnacijo lesa množično uporablja tudi bakrove spojine. Ker se dokaj slabo vežejo v les, se iz njega izpirajo. V kombinaciji s kromom pa se baker v lesu dobro fiksira. V zadnjem času so v mnogih državah omejili uporabo kromovih soli, oziroma jih nameravajo prepovedati. Strokovnjaki zato za fiksacijo bakra iščejo druge spojine. Kot primerni in potencialno uporabni so se izkazaliamini. Raziskovali smo interakcije med bakrovimi pripravki z etanolaminom (C2H7NO, 2-aminoetanol) in komponentami lesa. Opazili smo, da etanolamin z lesom reagira. Z metodo nihajne spektroskopije (FTIR) smo opazilispremembe na skupinah lignina in polioz. Razvili smo tudi metodo, kjer reagent z barvno reakcijo dokaže prisotnost etanolamina v lesu.