Narrowband Searches for Continuous and Long-duration Transient Gravitational Waves from Known Pulsars in the LIGO-Virgo Third Observing Run

Isolated neutron stars that are asymmetric with respect to their spin axis are possible sources of detectable continuous gravitational waves. This paper presents a fully coherent search for such signals from eighteen pulsars in data from LIGO and Virgo's third observing run (O3). For known pulsars, efficient and sensitive matched-filter searches can be carried out if one assumes the gravitational radiation is phase-locked to the electromagnetic emission. In the search presented here, we relax this assumption and allow both the frequency and the time derivative of the frequency of the gravitational waves to vary in a small range around those inferred from electromagnetic observations. We find no evidence for continuous gravitational waves, and set upper limits on the strain amplitude for each target. These limits are more constraining for seven of the targets than the spin-down limit defined by ascribing all rotational energy loss to gravitational radiation. In an additional search, we look in O3 data for long-duration (hours-months) transient gravitational waves in the aftermath of pulsar glitches for six targets with a total of nine glitches. We report two marginal outliers from this search, but find no clear evidence for such emission either. The resulting duration-dependent strain upper limits do not surpass indirect energy constraints for any of these targets. © 2022. The Author(s). Published by the American Astronomical Society

Improved size distribution of AgBiS2 colloidal nanocrystals by optimized synthetic route enhances photovoltaic performance

Ternary silver bismuth sulfide (AgBiS2) colloidal nanocrystals (NCs) have been recognized as a photovoltaic absorber for environmentally-friendly and low-temperature-processed thin film solar cells. However, previous synthetic methods involving hot injection of sulfur precursors into metal oleate precursor solutions do not provide a balance between nucleation and growth, leading to AgBiS2 NCs with broad size distributions. Here, we demonstrate the modified synthetic route that size distribution of AgBiS2 NCs can be improved by pre-adding the non-coordinating 1-octadecene (ODE) solvent into metal precursor solutions, leading to controlled concentration of coordinating oleic acid with improved hot-injection synthetic conditions. The addition of ODE as a non-coordinating solvent to metal precursor/oleic acid solution significantly suppresses variations in the concentration of coordinating oleic acid after injection of the sulfur precursor solution, leading to a homogenous reaction between the metal and sulfur precursors. For photovoltaic devices fabricated using the resultant AgBiS2 NCs, the champion device shows power conversion efficiency (PCE) of 5.94% with an open-circuit voltage (VOC) of 0.52 V. This performance is better than that a control device (PCE of 5.50% and VOC of 0.49 V) because of the reduced energetic disorder and band tail broadening originating from the uniformly-sized AgBiS2 NCs. © 2020 John Wiley & Sons Ltd1

Beam Diagnostic System for High Intensity Proton Linac at KAERI

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Fecundação e clivagem após a ativação da proteína quinase C durante a maturação de oócitos bovinos Fertilization and cleavage after protein kinase C activation during bovine oocyte maturation

A formação de pró-núcleos, clivagem e perfil protéico foram avaliados após a ativação da proteína quinase C (PQ-C) durante a maturação de complexos cumulus-oócito (CCOs) bovinos. Visando a determinar estes efeitos da PQ-C, 1936 CCOs foram distribuídos aleatoriamente em 4 tratamentos, sendo maturados na presença de PMA (100nM phorbol 12-myristate 13-acetate, ativador da PQ-C), de 4alfa-PDD (100nM de 4alfa-phorbol 12,13-didecanoetate, forbol éster que não ativa a PQ-C; controle forbol éster), de SVE (10% de soro de vaca em estro, controle positivo) e de um controle negativo constituído pelo meio de maturação básico para os demais tratamentos, com exceção do SVE, onde não foi adicionado o álcool polivinílico (PVA). Os CCOs foram mantidos na presença de PMA por 1, 4 e 7 horas, sendo após, transferidos para o meio básico de maturação até que se completassem 24 horas de cultivo. A estimulação da PQ-C, por esses períodos, não alterou a formação de pró-núcleos, porém, diminuiu a percentagem de clivagem dos zigotos. Os resultados do grupo 4alfa-PDD comprovam que as alterações ocorridas no grupo PMA são devido à ativação da PQ-C e não ação direta do forbol éster na célula. A análise da composição protéica demonstrou uma banda de proteína adicional no grupo SVE ao redor de 74 kilo Daltons (kDa). Os resultados desse estudo, quando associados aos dados preliminares de Western blot, indicam a importância da PQ-C na regulação da maturação, fecundação e clivagem de embriões bovinos.<br>In the present study the pronucleus formation, cleavage and protein profile after protein kinase C (PK-C) activation were evaluated during bovine oocyte maturation. A total number of 1936 bovine cumulus-oocyte complexes (COCs) were randomly distributed in 4 treatments, and matured with PMA (100nM phorbol 12-myristate 13-acetate, PK-C activator), 4alpha-PDD (100nM de 4alpha-phorbol 12,13-didecanoetate, phobol ester that do not bind on PK-C, phorbol ester control), ECS (10% of estrus cow serum, positive control) and in a negative control (basic maturation media for all treatments, except on ECS group where the polyvinyl alcohol was not added). The COCs were kept in presence of PMA for 1, 4 or 7 hours and then transferred to basic maturation media until the 24 hours maturation period was completed. The PK-C stimulation in these periods did not alter the pronucleus formation but caused a decrease in the zygotes cleavage rate. The 4alpha-PDD group results showed that the alterations in PMA group were caused by PK-C activation and not by direct phorbol ester action on the cell. The protein composition analysis showed an additional protein band on ECS group around 74 kilo Daltons (kDa). Altogether, these results with the preliminary Western Blot analysis, indicate an important role of PK-C on bovine oocyte maturation, fertilization and embryo cleavage