Effects of transient thermal shock loadings on the structure of zirconia ceramics

In this paper the influence of thermal shock loadings on the phase composition and microstructure of ZrO[2](Y[2]O[3]) and ZrO[2](MgO) ceramics was studied. It was found that thermal shock strains were no effect on phase composition of ZrO[2](Y[2]O[3]) ceramics. Reducing the concentration of high-temperature tetragonal t-ZrO[2] and cubic c-ZrO[2] modifications and rising the content of low-temperature monoclinic m-ZrO[2] crystal system with increasing the number of thermal shock strains were observed. The values of region coherent X-ray scattering of ZrO[2](Y[2]O[3]) ceramics didn't changed, while the crystallite size of ZrO[2](MgO) ceramics decreased. The formation of block structure in all studied ceramics was observed, the sizes of the blocks formed in the ZrO[2](Y[2]O[3]) and ZrO[2](MgO) ceramics were slightly different. The formation of the blocks in ZrO[2](Y[2]O[3]) ceramics occurred on the grain boundaries, while the crystallites in ZrO[2](MgO) ceramics were crushed due to phase transformation

Boundary relations and generalized resolvents of symmetric operators

The Kre\u{\i}n-Naimark formula provides a parametrization of all selfadjoint exit space extensions of a, not necessarily densely defined, symmetric operator, in terms of maximal dissipative (in \dC_+) holomorphic linear relations on the parameter space (the so-called Nevanlinna families). The new notion of a boundary relation makes it possible to interpret these parameter families as Weyl families of boundary relations and to establish a simple coupling method to construct the generalized resolvents from the given parameter family. The general version of the coupling method is introduced and the role of boundary relations and their Weyl families for the Kre\u{\i}n-Naimark formula is investigated and explained.Comment: 47 page

Update of the Unitarity Triangle Analysis

We present the status of the Unitarity Triangle Analysis (UTA), within the Standard Model (SM) and beyond, with experimental and theoretical inputs updated for the ICHEP 2010 conference. Within the SM, we find that the general consistency among all the constraints leaves space only to some tension (between the UTA prediction and the experimental measurement) in BR(B -> tau nu), sin(2 beta) and epsilon_K. In the UTA beyond the SM, we allow for New Physics (NP) effects in (Delta F)=2 processes. The hint of NP at the 2.9 sigma level in the B_s-\bar B_s mixing turns out to be confirmed by the present update, which includes the new D0 result on the dimuon charge asymmetry but not the new CDF measurement of phi_s, being the likelihood not yet released.Comment: 4 pages, 2 figures, Proceedings of the 35th International Conference of High Energy Physics - ICHEP2010 (July 22-28, 2010, Paris

Spin-dependent recombination mechanisms for quintet bi-excitons generated through singlet fission

We investigate the physical mechanisms for spin-dependent recombination of a strongly bound pair of triplet excitons generated by singlet fission and forming a spin quintet (total spin of two) bi-exciton. For triplet excitons the spin-dependent recombination pathways can involve intersystem crossing or triplet-triplet annihilation back to the singlet ground state. However the modeling of spin-dependent recombination for quintets is still an open question. Here we introduce two theoretical models and compare their predictions with the broadband optically detected magnetic resonance spectrum of a long lived quintet bi-exciton with known molecular structure. This spectrum measures the change in the fluorescence signal induced by microwave excitation of each of the ten possible spin transitions within the quintet manifold as function of the magnetic field. While most of the experimental features can be reproduced for both models, the behavior of some of the transitions is only consistent with the quintet spin-recombination model inspired by triplet intersystem crossing which can reproduce accurately the experimental two-dimensional spectrum with a small number of kinetic parameters. Thus quantitative analysis of the broadband optically detected magnetic resonance signal enables quantitative understanding of the dominant spin-recombination processes and estimation of the out-of equilibrium spin populations.Comment: optimization code available at https://github.com/yneter/ampodm

Restrictions and extensions of semibounded operators

We study restriction and extension theory for semibounded Hermitian operators in the Hardy space of analytic functions on the disk D. Starting with the operator zd/dz, we show that, for every choice of a closed subset F in T=bd(D) of measure zero, there is a densely defined Hermitian restriction of zd/dz corresponding to boundary functions vanishing on F. For every such restriction operator, we classify all its selfadjoint extension, and for each we present a complete spectral picture. We prove that different sets F with the same cardinality can lead to quite different boundary-value problems, inequivalent selfadjoint extension operators, and quite different spectral configurations. As a tool in our analysis, we prove that the von Neumann deficiency spaces, for a fixed set F, have a natural presentation as reproducing kernel Hilbert spaces, with a Hurwitz zeta-function, restricted to FxF, as reproducing kernel.Comment: 63 pages, 11 figure

Регуляція морфогенезу in vitro у ліній кукурудзи групи Ланкастер

The aim of this work is the comparative evaluation of the influence of physiologically active substances (PAS) on the ratio of morphogenesis types in vitro and plant regeneration in callus tissues of maize inbreds of the Lancaster heterotic group. Lancaster inbreds of Ukrainian selection DК267, DК6080 and DК298 and lines PLS61, A188 and Chi31 of foreign selection which represented eponymous heterotic groups were selected for into the research. For callusogenesis induction immature embryos of 1.0–1.5 mm in length were planted on a modified N6 medium with 30 g/l sucrose. For regeneration the 30-day callus tissue was transplanted to a modified MS medium containing 20 g/l sucrose and various PAS: 6-benzylaminopurine (BAP) (0.1 mg/l) or indolylbutyric acid (IBA) (1.0 mg/l), or cefotaxime (CT) (150 mg/l). Morphogenesis and plant regeneration were obtained in callus tissue by organogenesis through the formation of leaf-like structures or shoots only without roots (hemmogenesis) and by embryogenesis through the development of embryos with the cooperative laying of the apexes of the shoot and the root. The predominant type of in vitro morphogenesis in both groups of genotypes was organogenesis. A tendency to increasing the embryogenesis level among Lancaster inbreds in comparison with the other investigated groups was observed. A certain tendency to increase the level of embryogenesis on a medium for regeneration with IBA, compared to other PAS, was marked. So, for the Lancaster group the embryogenesis level on the medium with IBA was 33.3%, while for the other investigated genotypes it was about 10.3%. Regeneration frequency was 45.8 plantlets/100 calli for Lancaster inbred DК298, 42.2 plantlets/100 calli for DК267 and 5.6 plantlets/100 calli for DК6080. Regeneration frequency of inbred PLS61 was 204.0 plantlets/100 calli, 100.0 plantlets/100 calli for Chi31 and 11.1 plantlets/100 calli for А188. Observed reductions in capacityfor plant regeneration of Lancaster inbreds may have been due to their pedigree. These inbreds belong to the commercial heterotic group that was not specially selected for increased regenerative ability, unlike the model inbreds of other heterotic groups. Overall, the level of regeneration frequency in the Lancaster group was 44.8 plantlets/100 calli on the medium under BAP, 41.4 plantlets/100 calli under IBA, and 20.7 plantlets/100 calli with CT. In general, the level of regeneration frequency for non-Lancaster heterotic groups reached 89.7 plantlets/100 calli on the medium with BAP, 96.7 plantlets/100 calli under IBA, and 93.1 plantlets/100 calli under CT. To enhance embryogenesis and frequency of regeneration for maize inbreds of the Lancaster group 30 g/l sucrose in the callusogenesis medium and physiologically active substance indolylbutyric acid (1.0 mg/l) in the medium for regeneration can be recommended.Охарактеризовано морфогенез in vitro на середовищі для регенерації у ліній кукурудзи гетерозисної групи Ланкастер порівняно з іншими гетерозисними групами – PLS61, А188 та Chi31 на базі 30-добової калусної тканини, отриманої з незрілих зародків, на фоні 30 г/л сахарози середовища для калусогенезу. Морфогенез in vitro у кукурудзи, який зумовлює отримання повноцінних фертильних рослин, відбувається двома шляхами: органогенезом і соматичним ембріогенезом (ембріоїдогенезом). Установлено генотиптипічний контроль за типом морфогенезу in vitro. Оцінено вплив фізіологічно активних речовин (6-бензиламінопурину, індолілмасляної кислоти та цефотаксиму) на співвідношення типів морфогенезу in vitro у ліній кукурудзи групи Ланкастер і неланкастерівських гетерозисних груп. Переважаючий тип морфогенезу in vitro – органогенез для всіх досліджених гетерозисних груп. Індолілмасляна кислота сприяє інтенсифікації процесу ембріоїдогенезу у разі застосування її як компонента регенераційного середовища як у ланкастерівських, так і неланкастерівських ліній. Відмічено значне переважання частоти регенерації у ліній PLS61, А188 та Chi31 над аналогічним показником для ліній групи Ланкастер. Охарактеризовано морфогенез in vitro на середовищі для регенерації у ліній кукурудзи гетерозисної групи Ланкастер порівняно з іншими гетерозисними групами – PLS61, А188 та Chi31 на базі 30-добової калусної тканини, отриманої з незрілих зародків, на фоні 30 г/л сахарози середовища для калусогенезу. Морфогенез in vitro у кукурудзи, який зумовлює отримання повноцінних фертильних рослин, відбувається двома шляхами: органогенезом і соматичним ембріогенезом (ембріоїдогенезом). Установлено генотиптипічний контроль за типом морфогенезу in vitro. Оцінено вплив фізіологічно активних речовин (6-бензиламінопурину, індолілмасляної кислоти та цефотаксиму) на співвідношення типів морфогенезу in vitro у ліній кукурудзи групи Ланкастер і неланкастерівських гетерозисних груп. Переважаючий тип морфогенезу in vitro – органогенез для всіх досліджених гетерозисних груп. Індолілмасляна кислота сприяє інтенсифікації процесу ембріоїдогенезу у разі застосування її як компонента регенераційного середовища як у ланкастерівських, так і неланкастерівських ліній. Відмічено значне переважання частоти регенерації у ліній PLS61, А188 та Chi31 над аналогічним показником для ліній групи Ланкастер.

Callusogenic potential of maize lines of Lancaster group in vitro

Оцінено лінії кукурудзи групи Ланкастер щодо реакції їх незрілих зародків на культивування in vitro. Здатність до калусогенезу зумовлена генотипом і залежить від наявності в родоводі лінії підплазми Oh43. Встановлено, що частота морфогенного калусогенезу для чутливих до культивування ліній групи Ланкастер складає 30–84 %. Визначено лінії, перспективні для використання у клітинній і генетичній інженерії кукурудзи за здатністю до утворення морфогенних калусів.Оценены линии кукурузы группы Ланкастер в отношении реакции их незрелых зародышей на культивирование in vitro. Способность к каллусогенезу обусловлена генотипом и зависит от наличия в родословной линии подплазмы Oh43. Установлено, что частота морфогенного каллусогенеза для чувствительных к культивированию линий группы Ланкастер находится на уровне 30–84 %. Выявлены линии, перспективные для использования в клеточной и генетической инженерии кукурузы по способности к образованию морфогенных каллусов.The estimation of maize inbred lines of theLancastergroup for immature embryos response to cultivation in vitro was made. It was noted that ability to callusogenesis was genotypically determined and depended on the presence of the subplasm Oh43 lineage. It was established that frequency of morphogenic callusogenesis in sensitive to cultivation Lancastergroup lines was at the level of 30–84 %. Promising maize inbreds cell and genetic engineering by an ability to produce morphogenic calli were identified