How predictable are spontaneous decisions and hidden intentions? Comparing classification results based on previous responses with multivariate pattern analysis of fMRI BOLD signals

In two replication studies we examined response bias and dependencies in voluntary decisions. We trained a linear classifier to predict “spontaneous decisions” and in the second study “hidden intentions” from responses in preceding trials and achieved comparable prediction accuracies as reported for multivariate pattern classification based on voxel activities in frontopolar cortex. We discuss implications of our findings and suggest ways to improve classification analyses of fMRI BOLD signals that may help to reduce effects of response dependencies between trials

Characteristics of orange-whey fermented beverages

The aim of the present work was to determine the populations of ABT culture microorganisms in orange and orangewhey drinks after fermentation and during 28-day storage. The evaluation involved fermented fruit drinks without whey or with added acid or sweet (rennet) whey. The Streptococcus thermophilus and Bifidobacteria counts were initially 3.5×105–8.3×105 CFU cm−3 and 2.4×106–5.9×106 CFU cm−3, respectively, and did not increase during fermentation. However, an increase was observed in the Lb. acidophilus count, which amounted to 3.0×106–2.4×107 CFU cm−3 after fermentation. During storage, the Str. thermophilus and Lb. acidophilus counts remained constant, but that for Bifidobacteria fell to 103 CFU cm−3 after 28 days. Bacteria survivability was higher in drinks containing whey than in non-whey orange drinks. In 100 cm3, antioxidant activity against ABTS/DPPH radicals varied between 260 and 550 μmol TE; vitamin C content was in the range of 15.7–17.6 mg; polyphenols were 26.6–34.4 mg (+)catechin. In the sensory evaluation the best results were obtained for non-whey drinks and those containing 50% acid whey

Thermal resistance of PCD materials with borides bonding phase

In these studies, one group of PCD materials was prepared using diamond powder and 10 wt % of TiB₂ and the second batch of the PCD material was prepared using a mixture of diamond powder with 5 wt % of TiB₂ and 2 wt % of Co. The materials have been sintered using a Bridgman-type high-pressure apparatus at 8.0±0.2 GPa, at a temperature of 2000±50 °C. Thermogravimetric (TG) measurements and Differential Thermal Analysis (DTA) have been carried out for diamond micropowders, TiB₂ bonding phase, and sintered composites. The coefficients of friction for diamond composites in a sliding contact with an Al₂O₃ ceramic ball have been determined from the room temperature up to 800 °C. Material phase compositions were analyzed for initial samples and after wear tests, at the temperature of 800 °C. Raman spectra of diamond composites with borides bonding phases, observed for the first-order zone centre modes of diamond and graphite during the heating up to 800 °C in air have been presented. Thermal properties have been compared with the commercial diamond-cobalt PCD. It has been found that diamond with TiB₂ and Co is the most resistant to the hardness changes at elevated temperatures and this material maintains the high hardness value up to 800 °C but it has a high coefficient of friction.Досліджено полікристалічні алмазні композити – одну групу матеріалів було приготовано з використанням алмазного порошку і 10 % (за масою) TiB₂, а другу – з алмазного порошку, 5 % (за масою) TiB₂ і 2 % (за масою) Co. Матеріали було спечено в апараті високого тиску типу Бріджмена при тиску 8,0±0,2 ГПа і температурі 2000±50 °С. Термогравіметричні вимірювання та диференційний термічний аналіз було проведено для алмазних мікропорошків, зв’язуючої фази TiB₂ і спечених композітов. Визначено коефіцієнти тертя для алмазних композитів при ковзному контакті з кулькою з кераміки Al₂O₃ при температурі від кімнатної до 800 °С. Фазові склади матеріалів проаналізовано для вихідних зразків і після їх випробування на знос при температурі 800 °С. Представлено спектри комбінаційного розсіювання алмазних композитів зі зв’язуючими фазами боридів, що спостерігаються в центрі зони першого порядку алмазу і графіту в процесі нагрівання до 800 °С на повітрі. Порівнювали термічні властивості отриманих полікристалічних алмазних композитів і промислового композита алмаз–кобальт. Було виявлено, що алмаз з TiB₂ і Co є найбільш стійким до змін твердості при підвищених температурах і зберігає високу твердість до 800 °С, але має високий коефіцієнт тертя.Исследованы поликристаллические алмазных композиты – одна группа материалов была приготовлена с использованием алмазного порошка и 10 % (по массе) TiB₂, а вторая – из алмазного порошка, 5 % (по массе) TiB₂ и 2 % (по массе) Co. Материалы были спечены в аппарате высокого давления типа Бриджмена при давлении 8,0±0,2 ГПа и температуре 2000±50 °С. Термогравиметрические измерения и дифференциальный термический анализ были проведены для алмазных микропорошков, связующей фазы TiB₂ и спеченных композитов. Определены коэффициенты трения для алмазных композитов при скользящем контакте с шариком из керамики Al₂O₃ при температуре от комнатной до 800 °С. Фазовые составы материалов проанализированы для исходных образцов и после их испытания на износ при температуре 800 °С. Представлены спектры комбинационного рассеяния алмазных композитов со связующими фазами боридов, наблюдаемые в центре зоны первого порядка алмаза и графита в процессе нагрева до 800 °С на воздухе. Сравнивали термические свойства полученных поликристаллических алмазных композитов и промышленного поликристаллического композита алмаз–кобальт. Было обнаружено, что алмаз с TiB₂ и Co является наиболее устойчивым к изменениям твердости при повышенных температурах и сохраняет высокую твердость до 800 °С, но имеет высокий коэффициент трения

TD-DFT insight into photodissociation of the Co-C bond in coenzyme B12

Coenzyme B12 (AdoCbl) is one of the most biologically active forms of vitamin B12, and continues to be a topic of active research interest. The mechanism of Co-C bond cleavage in AdoCbl, and the corresponding enzymatic reactions are however, not well understood at the molecular level. In this work, time-dependent density functional theory (TD-DFT) has been applied to investigate the photodissociation of coenzyme B12. To reduce computational cost, while retaining the major spectroscopic features of AdoCbl, a truncated model based on ribosylcobalamin (RibCbl) was used to simulate Co-C photodissociation. Equilibrium geometries of RibCbl were obtained by optimization at the DFT/BP86/TZVP level of theory, and low-lying excited states were calculated by TD-DFT using the same functional and basis set. The calculated singlet states, and absorption spectra were simulated in both the gas phase, and water, using the polarizable continuum model (PCM). Both spectra were in reasonable agreement with experimental data, and potential energy curves based on vertical excitations were plotted to explore the nature of Co-C bond dissociation. It was found that a repulsive 3(σCo-C → σ* Co-C) triplet state became dissociative at large Co-C bond distance, similar to a previous observation for methylcobalamin (MeCbl). Furthermore, potential energy surfaces (PESs) obtained as a function of both Co-CRib and Co-NIm distances, identify the S1 state as a key intermediate generated during photoexcitation of RibCbl, attributed to a mixture of a metal-to-ligand charge transfer (MLCT) and a s bonding-ligand charge transfer (SBLCT) states

Tilted algebras and short chains of modules

We provide an affirmative answer for the question raised almost twenty years ago concerning the characterization of tilted artin algebras by the existence of a sincere finitely generated module which is not the middle of a short chain

Magnetic Properties of TbNi1 xAuxIn Compounds

Polycrystalline samples of $TbNi_{1-x}Au_{x}In$ for x = 0.1, 0.2, 0.4, 0.6 and 0.8 were prepared and studied by powder X-ray and neutron diffraction and ac magnetic susceptibility measurements. These compounds crystallize in the hexagonal ZrNiAl-type structure. With increasing Au content a change in the magnetic structure is observed. For x = 0.1, 0.2 and 0.4 the magnetic order is described by the propagation vector k = (1/2, 0, 1/2) while for x = 0.8 by k = (0, 0, 1/2). Between 1.5 K and the Néel temperature the magnetic order is stable

Electronically Excited States of Vitamin B12: Benchmark Calculations Including Time-Dependent Density Functional Theory and Correlated Ab Initio Methods

Time-dependent density functional theory (TD-DFT) and correlated ab initio methods have been applied to the electronically excited states of vitamin B12 (cyanocobalamin or CNCbl). Different experimental techniques have been used to probe the excited states of CNCbl, revealing many issues that remain poorly understood from an electronic structure point of view. Due to its efficient scaling with size, TD-DFT emerges as one of the most practical tools that can be used to predict the electronic properties of these fairly complex molecules. However, the description of excited states is strongly dependent on the type of functional used in the calculations. In the present contribution, the choice of a proper functional for vitamin B12 was evaluated in terms of its agreement with both experimental results and correlated ab initio calculations. Three different functionals, i.e. B3LYP, BP86, and LC-BLYP, were tested. In addition, the effect of relative contributions of DFT and HF to the exchange-correlation functional was investigated as a function of the range-separation parameter, {\mu}. The issues related to the underestimation of charge transfer (CT) excitation energies by TD-DFT was validated by Tozer's L diagnostic, which measures the spatial overlap between occupied and virtual orbitals involved in the particular excitation. The nature of low-lying excited states was also analyzed based on a comparison of TD-DFT and ab initio results. Based on an extensive comparision against experimental results and ab initio benchmark calculations, the BP86 functional was found to be the most appropriate in describing the electronic properties of CNCbl. Finally, an analysis of electronic transitions and a new re-assignment of some excitations are discussed.Comment: Accepted by the Journal of Chemistry

Mechanical properties of diamond–TiB2 composites

The presented paper characterizes the basic mechanical and physical properties of sintered diamond-titanium diboride (submicro) and diamond-titanium diboride (nano) composites. The effect of reduction of powder size from the submicron scale to the nano scale of the ceramic bonding phase (TiB₂) in diamond composites on selected mechanical properties (Young’s modulus, Vickers hardness, fracture toughness, coefficient of friction) has been reported. Composites were prepared from initial powders of diamond (MDA36, Element Six) with addition of 10 mass % submicron TiB₂ (H.C. Starck F) and 10 mass % nanopowder TiB₂ (American Elements). Compacts were sintered at pressure 8±0,5 GPa and 2233±50 K using the high pressure-high temperature Bridgman type apparatus. These investigations allow the possibility of using this materials to be enhacced as ceramic tool materials, in particular as burnishing tools.Наведені основні механічні та фізичні властивості спечених композитів на основі алмазу з додаванням субмікро- та нано-дибориду титану. Вивчено вплив розміру частинок порошку від субмікронного до нано-рівня в керамічній (TiB₂) складовій алмазних композитів на їх механічні властивості (модуль Юнга, твердість за Віккерсом, в'язкість руйнування, коефіцієнт тертя). Композити були отримані з вихідних порошків алмазу (MDA36, Element Six) з додаванням 10 мас. % субмікронного TiB₂ (HC Starck F) або 10 мас. % нанопорошку TiB₂ (American Elements). Зразки спечені при тиску 8±0,5 ГПа і температурі 2233±50 К в апараті високого тиску типу тороїд. Результати досліджень вказують на можливість використання одержаних композитів як інструментальних матеріалів підвищеної якості, зокрема в інструментах для вигладжування.Приведены основные механические и физические свойства спеченных композитов на основе алмаза с добавками субмикро- и нано-диборида титана. Изучено влияние размера частиц порошка от субмикронного до нано-уровня в керамической (TiB₂) составляющей алмазных композитов на их механические свойства (модуль Юнга, твердость по Виккерсу, вязкость разрушения, коэффициент трения). Композиты были получены из исходных порошков алмаза (MDA36, Element Six) с добавлением 10 масс. % субмикронного TiB₂ (HC Starck F) или 10 масс. % нанопорошка TiB₂ (American Elements). Образцы были спечены при давлении 8±0,5 ГПа и температуре 2233±50 К в аппарате высокого давления типа тороид. Результаты исследований указывают на возможность использования полученных композитов в качестве улучшенных инструментальных материалов, в частности в выглаживающих инструментах