Analysis of diffusion process influence on oxidative coupling of methane

It is shown that oxidative coupling of methane at the reaction conditions has no transport limitations (kinetic regime). On the base of the thermodynamic modeling and experiment a key role of the catalysts influence on reaction selectivity was shown

Using Diatoms (Class Bacillariophyceae) as a biological proxy for environmental changes in the Canterbury high country, Lake Hawdon, New Zealand.

This study examined samples part of a larger project exploring environmental changes at Lake Hawdon, mid Canterbury, involving Queen’s University Belfast and the University of Canterbury. The author was responsible for the analysis of 85 fossil diatom samples from Lake Hawdon to create a high resolution study to assess their use as a biological proxy of past environmental changes through the Late Glacial Inter-Glacial Transition. Qualitative interpretations suggest three main phases of environmental change in Lake Hawdon during ~17,000 to 10,000 cal. BP. The first is a cool stage where taxa such as Cocconeis placentula and fragilarioid complex taxa Staurosirella pinnata and Pseudostaurosira brevistriata suggest a cool shallow lake with increasing macrophyte growth. The second phase suggests cold deepening water from at 13,928 +/- 142 to 12,686 +/- 166 cal. BP, dominated by Pseudostaurosira brevistriata, which coincides with the Antarctic Cold Reversal. The third phase represents a warm deep water phase after 12,686 +/- 166 cal. BP, dominated by planktonic taxon Cyclotella stelligera and epiphytic taxon Epithemia sorex, suggesting that Lake Hawdon does not exhibit the Younger Dryas event. Pollen and chironomid data from Lake Hawdon, generated by other project members, are included in the quantitative analyses to further inform palaeoenvironmental inferences generated from diatom data. Chironomid temperature reconstructions complement diatom interpretations for all three phases of change in the lake however diatom resolution allows changes to be detected earlier than other proxies suggest. Stabilisation of the landscape ~12, 686 +/- 166 cal. BP is suggested by tree pollen appearing near the end of the diatom cold phase, confirming with the diatoms and chironomid data that there was a warming out of the cold phase. Interpretations from Lake Hawdon add to other proxy studies in New Zealand that suggest an Antarctic Cold Reversal type event, but fail to highlight the Younger Dryas event. The generation of a transfer function was attempted with the diatom data based on Northern Hemisphere datasets, but a Principal Component Analysis plot highlighted major dissimilarities between the New Zealand fossil data and modern European data. This raised the issue of having morphologically similar but genetically separate taxa, potentially displaying convergent environmental adaptation, a crucial area for further research globally, and particularly in isolated areas like New Zealand

История и перспективы применения железобетона

Строительство из бетона и железобетона по праву можно назвать самым перспективным из существующих технологий возведения зданий. «Бетон – наилучший из материалов, изобретенных человечеством», – сказал знаменитый итальянский архитектор П.Л. Нерви. И он был прав. Сегодня большинство домов в современных городах сделано из бетона. Он применяется для строительства мостов, портов и плотин, дорог, подземных сооружений, атомных электростанций и стартовых площадок для ракет

A Compartmented Flow Microreactor System for Automated Optimization of Bioprocesses Applying Immobilized Enzymes

In the course of their development, industrial biocatalysis processes have to be optimized in small-scale, e. g., within microfluidic bioreactors. Recently, we introduced a novel microfluidic reactor device, which can handle defined reaction compartments of up to 250 μL in combination with magnetic micro carriers. By transferring the magnetic carriers between subsequent compartments of differing compositions, small scale synthesis, and bioanalytical assays can be conducted. In the current work, this device is modified and extended to broaden its application range to the screening and optimization of bioprocesses applying immobilized enzymes. Besides scaling the maximum compartment volume up to 3 mL, a temperature control module, as well as a focused infrared spot were integrated. By adjusting the pump rate, compartment volumes can be accurately dosed with an error <5% and adjusted to the requested temperature within less than a minute. For demonstration of bioprocess parameter optimization within such compartments, the influence of pH, temperature, substrate concentration, and enzyme carrier loading was automatically screened for the case of transferring UDP-Gal onto N-acetylglucosamine linked to a tert-butyloxycarbonyl protected amino group using immobilized β1,4-galactosyltransferase-1. In addition, multiple recycling of the enzyme carriers and the use of increased compartment volumes also allows the simple production of preparative amounts of reaction products

Электрохимические свойства наночастиц серебра на графитовом электроде

В настоящей работе было показано, что наночастицы серебра, полученные при молярном соотношении реагентов [AgNO3]: [Na3C6H5O7] = 1:1 в условии отсутствии стабилизатора с высоким молекулярным весом, обладают максимальной электрохимической активностью, что связано с неполным восстановлением ионов серебра. Этот факт соотносится с данными УФ-спектроскопии. Наночастицы серебра, полученные в избытке восстановителя при молярном соотношении реагентов [AgNO3]: [Na3C6H5O7] = 1:5 электрохимически неактивны, что также соответствует данным УФ- спектроскопии. Увеличение активности наночастиц серебра происходит в условии увеличения диапазона изменения потенциала, что может быть вызвано образованием перекиси водорода, обладающей активационной способностью. В данной работе установлены оптимальные условия, в которых наночастицы серебра являются наиболее электрохимически активны

Public Social Welfare System

The relevance of this study is determined by the fact that the economic welfare of the society depends not only on commercial but also public budget activities. Citizens with different income levels are interested in the stable public social safety net. It is important to understand the nature and efficiency of the public welfare system aimed at protecting social and economic welfare for different categories of citizens. The study uses the benchmark method to understand the key trends. The analytical method of research is used to understand the common problems of the public welfare system. In Russia, the public social safety net has been established in order to protect social and economic welfare of those citizens who are unable to do it themselves. This system includes legal, financial, and organizational components. The laws specify the categories of people who are eligible to receive aid from public authorities. The system provides for welfare payments in cash and social services to citizens. Payments in cash are sourced from budgets of different levels. Social institutions are divided into several groups depending on sources of funding. The pension and health care systems in Vietnam have in common with those in Russia. However, citizens in Vietnam are more involved in funding these systems. The accounting and public contracting system allows social organizations to use public funds in an efficient and targeted manner. There are some problems of funding the social sector in remote areas. These problems can be solved through differential funding

Выбор параметров установок продольной и поперечной компенсаций дальних электропередач с промежуточными системами

Приведены аналитические выражения по определению компенсирующих устройств дальних электропередач в зависимости от места присоединения ПС (к вводу или выводу установок продольной емкостной компенсации) с учетом предельности режима