Fischer-Tropsch synthesis on carbon nanotube-supported catalysts in water-in-oil emulsion

Fischer-Tropsch synthesis (FTS) is an important gas-to-liquids technology in the modern energy industry. The current trend is to carry it out in liquid reaction media in order to take advantage of good heat transfer, high catalyst efficiency, convenience for catalyst regeneration/reloading and lower costs, due to either the use of liquid media or the associated reactor designs. Adding water vapor to FTS has been proven to promote the reaction in many catalyst systems, but there was no attempt prior to this point to add liquid water in organic media. The choice of catalyst supports would be critical from multiple perspectives. First of all, the co-existence of both water and oil necessitates a support that could maximize the liquid interface for better mass transfer as well as dispersion of the catalyst. The product-support interaction is another important issue, especially for FTS product in liquid phase where secondary reaction happens when primary products re-adsorb onto catalysts. And finally, as with any catalyst, the metal-support interaction greatly affects the catalyst particle sizes and reactivity. We chose Ru catalyst supported on a multi-walled carbon nanotube/MgO-Al2O3 hybrid as the catalyst support for biphasic FTS, and carried out systematic studies that rationalized the choice of the support in terms of catalyst activity, deactivation, production selectivity as well as product separation. As it turned out, the amphiphilic properties of the nanohybrid-supported catalyst and the thus formed emulsion system were among the essential factors in the successful implement of the concept. A comprehensive interpretation of the results and a comparative investigation with some other catalyst supports have revealed the importance of choosing the right catalyst support, as well as given a better understanding of the FTS mechanism that incorporates recent progress reported in literature. We then went on to study the synthesis of carbon nanotubes (CNTs) in the effort to find optimal conditions for their production. In addition, sharing similarities in mechanistic pathways in a broad sense, but with much heavier molecular weight, CNTs have stronger interaction with catalyst supports than FTS products and were therefore a more typical model to study and demonstrate the product-support interaction as well. On the planar substrate support, depending on the isotropy/anisotropy of the CNT-support interaction, either random networks or aligned arrays of CNT films were synthesized on the corresponding support. Here another important continuation from the study of FTS was the promoting effects of water. We’ve concluded that water facilitates CNT growth in the second step, i.e., the step where monomeric C units condense into CNTs, while in the case of FTS, water plays a role mostly in the first step of CO dissociating into the monomeric CH species. Finally, a novel method to fabricate devices of the CNT films were presented that tested the merits of using planar supports for CNT growth in actual applications

Bridging The Gap: A Framework For Structuring The Asset Administration Shell In Digital Twin Implementation For Industry 4.0

The digital twin is a core technology for implementing Industry 4.0 scenarios in scientific and industrial applications. One upcoming variant of the digital twin is the concept of the asset administration shell, representing an approach to standardization. This approach must be adapted to specific use cases and applied in a target-oriented manner. However, no comprehensive guidance exists on structuring and implementing asset administration shells based on the digital twin in manufacturing environments. This issue pertains to defining and organizing the relevant data and mapping domain-specific limitations and characteristics within the hierarchical structure of the asset administration shell's components. This paper introduces an approach to structuring the asset administration shell to address this gap. This approach capitalizes on domain-specific expertise, industry standards, and established best practices, providing a framework. We validate the presented approach by applying it to the use case of distributed high-rate electrolyser production. The overarching objective of this research is to bridge the gap between theoretical concepts and practical applications

Track geometry monitoring by an on-board computer-vision-based sensor system

This article illustrates some outcomes of the EU project Assets4Rail, founded within the Shift2Rail Joint Undertaking. Nowadays, Track recording vehicles (TRV) are equipped with laser/optical systems with inertial units to monitor track geometry (TG). Dedicated trains and sophisticated measurement equipment are difficult, costly to acquire and maintain. So the time interval between two TRV recordings of the TG on the same line section cannot be too close (twice per month to twice per year). Recently, infrastructure managers have been more interested in using commercial trains to monitor track condition in a cost-effective manner. TRVs' expensive and constantly maintained optical systems make them unsuitable for commercial fleets. On-board sensor systems based on indirect measurements such as accelerations have been developed in various studies. While detecting the vertical irregularity is a straightforward method by doubling the recorded acceleration, it is yet an unsolved issue for lateral irregularities due to the complicated relative wheel-rail motion. The proposed system combines wheel-rail transversal relative position data with on-board lateral acceleration sensors to detect lateral alignment issues. It includes a functional prototype of an on-board computer vision sensor capable of monitoring Lateral displacement for TG measurements. This eliminates measurement errors due to wheelset transverse displacements relative to the track, which is essential for calculating lateral alignment. The sensor system prototype was tested in Italy at 100 km/h on the Aldebaran 2.0 TRV of RFI, the main Italian Infrastructure Manager. It was found that the estimated lateral displacement well corresponds to the lateral alignment acquired by the Aldebaran 2.0 commercial TG inspection equipment. Moreover, due to the lack of measurement of the acceleration on board the Aldebaran 2.0 TRV, a Simpack® simulation provide with axle box acceleration values, to evaluate the correlation between them, LDWR and track alignment issues

INFLUENCE OF TRACK GEOMETRY CONDITION MONITORING ON RAILWAY INFRASTRUCTURE MAINTENANCE PROCESSING

This study analyzed the usage of data of track geometry measurement for railway infrastructure maintenance processing support and estimated its influence on railway infrastructure maintenance decision-making. Especially, the approach assessment of the influence of track geometry monitoring on railway infrastructure processing. The well-timed maintenance of the arrangement of railway tracks in allowable conditions is sufficient for the smooth and steady running of rail vehicles. The mechanism of track gauge widening during exploitation is usually gradual and relatively long-lasting. When are not detected in a timely manner, the final track failures often arise under the effect of additional factors, such as surpassed train speed limit, poorly maintained and functioning running gear of a rail vehicle, misalignment of rails, and extreme dynamical effects. A questionnaire considering the influence of the application of track geometry monitoring was formulated. An expert review was completed in order to perform a comparative analysis of the features of track geometry monitoring with the greatest influence on railway infrastructure maintenance processing. The data collected from respondents were processed using a multi-criterion estimation method, especially an interactive fuzzy linear assignment method. Finally, basic conclusions and considerations are given

Genome-Wide Identification, Evolutionary Expansion, and Expression Profile of Homeodomain-Leucine Zipper Gene Family in Poplar (Populus trichocarpa)

BACKGROUND: Homeodomain-leucine zipper (HD-ZIP) proteins are plant-specific transcriptional factors known to play crucial roles in plant development. Although sequence phylogeny analysis of Populus HD-ZIPs was carried out in a previous study, no systematic analysis incorporating genome organization, gene structure, and expression compendium has been conducted in model tree species Populus thus far. PRINCIPAL FINDINGS: In this study, a comprehensive analysis of Populus HD-ZIP gene family was performed. Sixty-three full-length HD-ZIP genes were found in Populus genome. These Populus HD-ZIP genes were phylogenetically clustered into four distinct subfamilies (HD-ZIP I-IV) and predominately distributed across 17 linkage groups (LG). Fifty genes from 25 Populus paralogous pairs were located in the duplicated blocks of Populus genome and then preferentially retained during the sequential evolutionary courses. Genomic organization analyses indicated that purifying selection has played a pivotal role in the retention and maintenance of Populus HD-ZIP gene family. Microarray analysis has shown that 21 Populus paralogous pairs have been differentially expressed across different tissues and under various stresses, with five paralogous pairs showing nearly identical expression patterns, 13 paralogous pairs being partially redundant and three paralogous pairs diversifying significantly. Quantitative real-time RT-PCR (qRT-PCR) analysis performed on 16 selected Populus HD-ZIP genes in different tissues and under both drought and salinity stresses confirms their tissue-specific and stress-inducible expression patterns. CONCLUSIONS: Genomic organizations indicated that segmental duplications contributed significantly to the expansion of Populus HD-ZIP gene family. Exon/intron organization and conserved motif composition of Populus HD-ZIPs are highly conservative in the same subfamily, suggesting the members in the same subfamilies may also have conservative functionalities. Microarray and qRT-PCR analyses showed that 89% (56 out of 63) of Populus HD-ZIPs were duplicate genes that might have been retained by substantial subfunctionalization. Taken together, these observations may lay the foundation for future functional analysis of Populus HD-ZIP genes to unravel their biological roles

Deep Learning based Virtual Point Tracking for Real-Time Target-less Dynamic Displacement Measurement in Railway Applications

In the application of computer-vision based displacement measurement, an optical target is usually required to prove the reference. In the case that the optical target cannot be attached to the measuring objective, edge detection, feature matching and template matching are the most common approaches in target-less photogrammetry. However, their performance significantly relies on parameter settings. This becomes problematic in dynamic scenes where complicated background texture exists and varies over time. To tackle this issue, we propose virtual point tracking for real-time target-less dynamic displacement measurement, incorporating deep learning techniques and domain knowledge. Our approach consists of three steps: 1) automatic calibration for detection of region of interest; 2) virtual point detection for each video frame using deep convolutional neural network; 3) domain-knowledge based rule engine for point tracking in adjacent frames. The proposed approach can be executed on an edge computer in a real-time manner (i.e. over 30 frames per second). We demonstrate our approach for a railway application, where the lateral displacement of the wheel on the rail is measured during operation. We also implement an algorithm using template matching and line detection as the baseline for comparison. The numerical experiments have been performed to evaluate the performance and the latency of our approach in the harsh railway environment with noisy and varying backgrounds

Impacts of climate change, population growth, and power sector decarbonization on urban building energy use

Climate, technologies, and socio-economic changes will influence future building energy use in cities. However, current low-resolution regional and state-level analyses are insufficient to reliably assist city-level decision-making. Here we estimate mid-century hourly building energy consumption in 277 U.S. urban areas using a bottom-up approach. The projected future climate change results in heterogeneous changes in energy use intensity (EUI) among urban areas, particularly under higher warming scenarios, with on average 10.1–37.7% increases in the frequency of peak building electricity EUI but over 110% increases in some cities. For each 1 °C of warming, the mean city-scale space-conditioning EUI experiences an average increase/decrease of ~14%/ ~ 10% for space cooling/heating. Heterogeneous city-scale building source energy use changes are primarily driven by population and power sector changes, on average ranging from –9% to 40% with consistent south–north gradients under different scenarios. Across the scenarios considered here, the changes in city-scale building source energy use, when averaged over all urban areas, are as follows: –2.5% to –2.0% due to climate change, 7.3% to 52.2% due to population growth, and –17.1% to –8.9% due to power sector decarbonization. Our findings underscore the necessity of considering intercity heterogeneity when developing sustainable and resilient urban energy systems.<br/

Clinical cure induced by pegylated interferon α-2b in the advantaged population of chronic hepatitis B virus infection: a retrospective cohort study

BackgroundAmong the advantaged population with clinical cure of chronic hepatitis B, chronic inactive hepatitis B virus carriers (IHCs) and nucleoside analog-experienced patients have similar serological manifestations. This study established non-interferon-treated groups as controls to compare the efficacy of pegylated interferon α-2b (Peg-IFNα-2b) in achieving clinical cure between IHCs and nucleoside analog (NA)-experienced patients.MethodA total of 270 patients were enrolled in this observational study. The IHC cohort comprised 55 patients who received Peg-IFNα-2b (Peg-IFN group), and the other 70 patients did not receive any antiviral treatment (untreated group). Patients treated with NAs were divided into two groups: one group (70 patients) receiving NA add-on Peg-IFNα-2b therapy regimen (NA add-on Peg-IFN group) and another group (75 patients) receiving continuous NA monotherapy (NA group). The primary endpoints were hepatitis B surface antigen (HBsAg) clearance and HBsAg seroconversion at 48 weeks and 72 weeks.ResultsAt 48 weeks, 65.5% (36/55) and 52.9% (37/70) patients achieved HBsAg clearance in the Peg-IFN group and NA add-on Peg-IFN group, respectively (p = 0.156). HBsAg seroconversion was achieved in 47.3% (26/55) of the Peg-IFN group and 34.3% (24/70) of the NA add-on Peg-IFN group (p = 0.141). At the follow-up of 72 weeks, 36 patients in the Peg-IFN group achieved HBsAg loss (65.5%, 36/55), and 33 patients in the NA add-on Peg-IFN group achieved HBsAg clearance (47.1%, 33/70), which were significantly higher than in the Peg-IFN group (p = 0.041). The HBsAg seroconversion rates in the Peg-IFN group and NA add-on Peg-IFN group at 72 weeks were 45.5% (25/55) and 32.9% (23/70), respectively (p = 0.151). No patient achieved HBsAg clearance or seroconversion in the NA group and untreated group. Furthermore, the receiver operating characteristic curve showed baseline HBsAg&lt; 72 IU/mL, and the decline of HBsAg of more than 80% and 98% from baseline to 12 and 24 weeks provided good predictions for HBsAg clearance. Meanwhile, 77% of patients with baseline HBsAg&lt; 100 IU/mL achieved a clinical cure at 48 weeks.ConclusionPeg-IFNα-2b results in a high rate of HBsAg clearance and seroconversion in both IHCs and NA-experienced patients, especially for those patients who have HBsAg below 100 IU/mL

Data for our paper "Robustness enhancement of machine fault diagnostic models for railway applications through data augmentation"

This vibration data can be used for machine fault diagnosis. The experiment data was measured on railway freight wagons by our research team in past years. The measurements were conducted on different positions on different wagons running on different track lines in different speed ranges with different measurement systems. The obtained data can undoubtedly represent real-world complexity. The faulty signals are induced by wheel flat, a flat spot on railway vehicles' wheel tread.EC/H2020/826250/EU/Measuring, monitoring and data handling for railway assets; bridges, tunnels, tracks and safety systems/Assets4Rai