Control of extrinsic porosities in linked metal-organic polyhedra gels by imparting coordination-driven self-assembly with electrostatic repulsion

The linkage of metal-organic polyhedra (MOPs) for the synthesis of porous soft materials is one of the promising strategies to combine processability with permanent porosity. Compared to the defined internal cavity of MOPs, it is still difficult to control the extrinsic porosities generated between crosslinked MOPs because of their random arrangements in their networks. Herein, we report a method to form linked MOP gels with controllable extrinsic porosities by introducing negative charges on the surface of MOPs that facilitates electrostatic repulsion between them. A hydrophilic rhodium-based cuboctahedral MOP (OHRhMOP) with 24 hydroxyl groups on its outer periphery can be controllably deprotonated to impart the MOP with tunable electrostatic repulsion in solution. This electrostatic repulsion between MOPs stabilizes the kinetically trapped state, in which a MOP is coordinated with various bisimidazole linkers in a monodentate fashion at a controllable link-er/MOP ratio. The heating of the kinetically trapped molecules leads to the formation of gels with similar colloidal networks but different extrinsic porosity. This strategy allows us to design the molecular-level networks and the resulting porosities even in the amorphous state.

PERCEPTION OF TEACHER’S LEADERSHIP BY PRE-SERVICE AND IN-SERVICE TEACHERS IN KAZAKHSTAN

The study describes the content and structure of the concept of teachers’ leadership from the pre-service and in-service teachers’ perspective. The method of obtaining data is a free-associative experiment with the registration of answers given to the verbal stimulus “teachers’ leadership”. The results are presented in the form of an associative field where we distinguish the nucleus, near, far, and outer periphery, compiled based on frequency analysis of the respondents’ reactions. By cognitive analysis of the associative field “teachers’ leadership” in the verbal consciousness of the pre-service and in-service teachers, semantic zones in its structure are distinguished.

Induction of inverted morphology in brain organoids by vertical-mixing bioreactors

Organoid technology provides an opportunity to generate brain-like structures by recapitulating developmental steps in the manner of self-organization. Here we examined the vertical-mixing effect on brain organoid structures using bioreactors and established inverted brain organoids. The organoids generated by vertical mixing showed neurons that migrated from the outer periphery to the inner core of organoids, in contrast to orbital mixing. Computational analysis of flow dynamics clarified that, by comparison with orbital mixing, vertical mixing maintained the high turbulent energy around organoids, and continuously kept inter-organoid distances by dispersing and adding uniform rheological force on organoids. To uncover the mechanisms of the inverted structure, we investigated the direction of primary cilia, a cellular mechanosensor. Primary cilia of neural progenitors by vertical mixing were aligned in a multidirectional manner, and those by orbital mixing in a bidirectional manner. Single-cell RNA sequencing revealed that neurons of inverted brain organoids presented a GABAergic character of the ventral forebrain. These results suggest that controlling fluid dynamics by biomechanical engineering can direct stem cell differentiation of brain organoids, and that inverted brain organoids will be applicable for studying human brain development and disorders in the future.

Quantitative assessment of the vascularity of the skeletally immature patella: a cadaveric study using MRI

Purpose While predominant blood supply to the adult patella enters inferomedially, little is known about skeletally immature patellar perfusion. Improved knowledge of immature patella vascularity can further understanding of osteochondritis dissecans, dorsal defects of the patella and bipartite patella, and help ensure safe surgical approaches. We hypothesized that the immature patella would exhibit more uniform blood flow. The study purpose was to quantify immature patella regional perfusion in comparison with adults. Methods Ten cadaveric knees were utilized (five immature, five mature). The superficial femoral artery was cannulated proximally. Signal enhancement increases were compared from pre- to post-contrast MRI to assess relative arterial contributions to patella regions (quadrants, anterior/posterior, superior/inferior, medial/lateral, and outer/inner). Results Quantitative-MRI analysis revealed similar distribution of enhancement between the immature and mature patella. The inferior pole exhibited significantly higher arterial contribution versus superior pole in both immature and mature groups (p = 0.009; both groups), while the inferomedial quadrant had the highest arterial contribution of all quadrants in both groups. The superolateral quadrant demonstrated the lowest arterial contribution in the immature group and second lowest in the adult group. The patella outer periphery had significantly greater arterial contribution than the inner central region in both immature (p = 0.009) and mature (p = 0.009) groups. Conclusion Distribution of arterial contributions between the immature and mature patella was similar. Our results highlight the importance of inferior and inferomedial blood supply in both immature and mature patellas. These findings have implications for paediatric and adult patients; surgical damage to inferior patellar vessels should be avoided to prevent associated complications.

Pushing the Boundaries of Plug Milling in Deformed Liners – Best Practices and Lessons Learned

This paper presents a systematic workflow/methodology developed to evaluate the milling operations using coiled tubing to remove frac plugs in a well with deformed liner, post hydraulic fracturing. This paper also presents the challenges encountered during intervention and steps on how they were mitigated. The well was completed by hydraulic fracturing of five stages, each separated by a frac plug. Post stimulation, coiled tubing was mobilized to mill the plugs and provide a full bore to begin production. After spending substantial time while attempting to mill in the initial run, decision was made to POOH and inspect the BHA. It was observed that the mill had significant metal loss on the outer periphery with no damage to the mill face, which thereby concluded the presence of liner damage. A strategy was developed on how to remediate this challenge. Multiple coiled tubing diagnostic runs were performed with real-time coiled tubing capabilities, which included cleanout, camera and caliper runs. Results of each coiled tubing run performed was carefully evaluated to estimate the extent of liner damage. The caliper and video camera runs were important to determine the new reduced ID of the liner. An initial milling attempt with a 3.33" OD mill was performed, which was the smallest size based on the plug manufacturers recommendation. However due to the specific nature of liner damage it could not pass through the restriction. After further discussions, a calculated risk was taken to run with a 3.125" OD mill, which was significantly smaller than the manufacturer's recommendation, and posed an inherent threat of milling through the core of the plug, while leaving the slips intact. This however did not happen, and all four plugs were successfully milled out from the liner, allowing full bore access and well to be flowed back. This paper will act as a guideline on how to design and execute an intervention operation in deformed liners.

Framework of E-Governance at the Grass Roots Level

E-government theories are prevailing in a variety of formats and concepts around the globe, nations, and institutions, but there are not many examples to emulate in terms of developing a comprehensive framework of e-governance system at the outer periphery of the government tiers. This research would like to carry out a comprehensive analysis on various theories built around the e-governance perception, but the prime focus will be devoted to the penetration of e-government system, particularly at the grassroots. To narrow down further, the study will conduct analytical observations in a few developed, developing, and transitional economies. Furthermore, to be more concise, the research will specifically focus on various e-government implementations at the grass roots that penetrated the lowest tier of the governance system for community empowerment and knowledge enhancement. Before conclusion, it will try to put forward prospective research agenda, including the framework of a future e-government system at the local government level.

Implementing Different Tubular Framings on High-Rise Structures and Optimizing their Cost and Drift Control with an Optimum Column Spacing

This paper presents the results of variation in column spacing of a tube in its outer periphery concerning structural drift and cost optimization. For high rise structures, tubular framing and outrigger braced frames are considered as the most appropriate solution economically. In recent past not must study has been focused on the tubular frame in its columns spacing and span length. In this research, a simple square plan structure has been considered with different heights of 30, 40, and 50 story buildings. Six different framing systems of the tubular structure have been developed with different column spacing in each and employed to each high-rise structure. Concrete strength and steel yield strength has been taken as a fixed value for every model. Several models were developed with these combinations and the drift and structural safety have been optimized by reducing the cross-section sizes in each system. Seismic analysis has been carried out to evaluate the effects of varying column spacing in each tube. The comparison of all the employed systems was carried out and cost analysis has been made. Observations have been taken from drift, base shear, and cost analysis of each framing system of the tube, and certain results were concluded for structures with different height.

The functioning of the nominative field vocabulary in German-language media against the background of nuclear power phase-out

Постановка задачи. Семантико-когнитивный метод анализа языка как способ исследования концептов представляет интерес, поскольку позволяет выявить когнитивные признаки концепта на широком и репрезентативном материале. В настоящем исследовании заявленный метод представлен в части, касающейся анализа лексикографических данных и когнитивной интерпретации контекстов употребления лексем номинативного поля Atomkraft в немецком языке. Целью статьи является установление когнитивных признаков лексем номинативного поля Atomkraft , кодифицированных в словарях и выявляемых в ходе анализа корпуса текстов публикаций в СМИ и блогах в период с 1980 по 2014 гг., для последующего построения полевой модели концепта. Особый интерес представляет влияние произошедших в данный период техногенных катастроф в секторе ядерной энергетики (ЯЭ) на частотность употребления и семантику обозначенных лексических единиц. Результаты. На основании анализа словарных статей, а также привлечения репрезентативного корпуса текстов устанавливается, что доминантным когнитивным признаком концепта является «отказ от ядерной энергетики», наиболее широко представленный лексемой Atomenergie . Общая полевая структура концепта с учетом всех номинативных единиц выглядит следующим образом: ядро составляет признак «отказ от ядерной энергетики» (31%); ближнюю периферию - «политические аспекты» и «опасности ЯЭ» (31%); дальнюю периферию - «вопросы экологии» и «будущее ЯЭ» (17%); крайнюю периферию - «ЯЭ как одна из проблем современности» и «мирное использование ЯЭ» (9%). Выводы. Дискуссионным продолжает оставаться вопрос о наличии корреляции между частотностью употребления лексических единиц рассматриваемого поля и происходящими в мире техногенными катастрофами. В рамках представленного исследования не было выявлено достоверных свидетельств подобной взаимосвязи. В ходе работы установлено, что пик употребления лексических единиц номинативного поля приходится на 2008-2009 гг., когда в Германии проходила подготовка и проведение предвыборной кампании в парламент, что позволяет сделать предположение о большем влиянии политической обстановки на семантическое наполнение концепта. Данная проблема, однако, требует дальнейших исследований на расширенном корпусе текстов. Statement of the problem. The semantic-cognitive method of language analysis as a means of studying concepts is of interest, because it allows one to identify the cognitive attributes of the concept on a wide and representative material. In the present study, the claimed method is presented in part regarding the analysis of lexicographic data and the cognitive interpretation of the contexts of the use of Atomkraft nominative field lexemes in German. The purpose of the article is to establish the cognitive features of the Atomkraft nominative field lexemes, codified in dictionaries and revealed during the analysis of the text corpus of publications in the media and blogs from 1980 to 2014, for the subsequent construction of a field model of the concept. Of particular interest is the effect of technological disasters in the nuclear energy sector that occurred during this period on the frequency of use and semantics of designated lexical units. Results. Based on the analysis of vocabulary entries, as well as the involvement of a representative text corpus, it is established that the dominant cognitive feature of the concept is “rejection of nuclear energy”, the most widely represented by the token Atomenergie . The general field structure of the concept, taking into account all nominative units, is as follows: the core is a sign of “abandonment of nuclear energy” (31%); the near periphery - “political aspects” and “dangers of nuclear power” (31%); the far periphery - “environmental issues” and “the future of nuclear power” (17%); the outer periphery - “nuclear power as one of the problems of our time” and “peaceful use of nuclear energy” (9%). Conclusion. The question of whether there is a correlation between the frequency of use of the lexical units of the field in question and the technological disasters occurring in the world continues to remain debatable. In the framework of the presented study, no reliable evidence of such a relationship was revealed. In the course of the work, it was found that the peak of the use of lexical units of the nominative field occurred in 2008-2009, when preparations for and pre-election campaigns were held in Germany, which suggests the greater influence of the political situation on the semantic content of the concept. This problem, however, requires further research on an expanded corpus of texts.

As-Built and Post-treated Microstructures of an Electron Beam Melting (EBM) Produced Nickel-Based Superalloy

The microstructures of an electron beam melted (EBM) nickel-based superalloy (Alloy 718) were comprehensively investigated in as-built and post-treated conditions, with particular focus individually on the contour (outer periphery) and hatch (core) regions of the build. The hatch region exhibited columnar grains with strong 〈001〉 texture in the build direction, while the contour region had a mix of columnar and equiaxed grains, with no preferred crystallographic texture. Both regions exhibited nearly identical hardness and carbide content. However, the contour region showed a higher number density of fine carbides compared to the hatch. The as-built material was subjected to two distinct post-treatments: (1) hot isostatic pressing (HIP) and (2) HIP plus heat treatment (HIP + HT), with the latter carried out as a single cycle inside the HIP vessel. Both post-treatments resulted in nearly an order of magnitude decrease in defect content in hatch and contour regions. HIP + HT led to grain coarsening in the contour, but did not alter the microstructure in the hatch region. Different factors that may be responsible for grain growth, such as grain size, grain orientation, grain boundary curvature and secondary phase particles, are discussed. The differences in carbide sizes in the hatch and contour regions appeared to decrease after post-treatment. After HIP + HT, similar higher hardness was observed in both the hatch and contour regions compared to the as-built material.