Seismic Strengthening of Existing RC Buildings With External Cross-Laminated Timber (CLT) Walls Hosting an Integrated Energetic and Architectural Renovation

In this study a timber-based integrated solution is presented to solve at once common issues affecting typical reinforced concrete (RC) existing buildings, such as seismic and energy performances, providing an eco-friendly alternative to steel external bracing systems. Cross-laminated timber (CLT) walls are provided perpendicularly to the external façades as strengthening elements while interposed CLT slabs are foreseen at each floor level to host new architectural units together with a new envelope. While the connections to the foundations and to the existing RC frames are provided respectively with steel brackets and axial-connectors distributed along the height of the building, a post-tensioned connection, between CLT panels (PT-CLT connection), is implemented in the system to guarantee resistance to horizontal actions acting parallel to existing façades with consequent structural independence and architectural freedom. A numerical model is developed with finite element software characterizing each type of connector for linear and non-linear analyses. Modal analyses with response spectrum are performed to verify structural elements and connectors, while pushover analyses with target displacement checks are performed to assess the obtained seismic improvement. Finally, the preassembled architectural components that allow to renovate the envelope and the provided assembly procedure are revealed.

Study on the Universal Tapered Segmental Ring Assembly Simulation Algorithm and Deviation Assessment: A Case Study on Metro Line Tunnel

Universal tapered segmental ring system has been adopted to assemble tangent and curve line elements into the shield tunnels through the relative rotation of the adjacent front and rear rings, which simplifies the formwork design, demonstrates strong universality, and is easy for quality assurance. To evaluate the position deviation caused by the taper value and propose the assembly scheme for the contractor, this article developed the universal tapered segmental ring assembly simulation technology. Firstly, the assembly procedure of the universal tapered segmental ring system both in normal case and in special case is introduced, including the interval tunnel of special rings and actual engineering that needs deviation correction. Secondly, relevant core algorithms are introduced in detail, including the coordinate position algorithm of horizontal and vertical curves and computer graphic algorithm of spatial point rotating around any axis. Finally, this article takes a background metro line tunnel as a case to validate the algorithm and illustrate the assessment methodology of universal tapered segmental ring assembly accuracy. The sections with maximum deviation are found as an alert ahead of the shield advancing. In conclusion, the algorithms and methodology proposed in this article illustrate the excellent suitability and robustness in shield tunnels adopting a universal tapered segmental ring system in the stage of both design and construction.

Biaxial testing of textile material - methodology and instrument assembly procedure

Membrane structures are becoming popular because of the potential usage in structures with higher aesthetic claims. For the roofing of these structures, different textile materials are used. These special materials offer an alternative to conventional roofing materials and allow, besides its lightweightness, also a possibility to roof a difficult floor plan and big span. When designing such a construction, there are some challenges related to the properties of the specific material. In order to exploit the full potential of textile membrane materials, it is necessary to choose an appropriate material model for numerical modelling, which takes into account its nonlinear behaviour. The two most important material characteristics needed for characterizing the behaviour are Young’s modulus of elasticity and Poisson’s ratio. Since the material is orthotropic in most cases, it is necessary to test the material in two directions; therefore, these characteristics need to be obtained from the biaxial test. This contribution is focused on the research of the methodology of biaxial tests and test instrument assembly procedure, which will be used for the following testing of textile materials.

Experimental Validation of Subsystem Models for a Novel Variable Displacement Hydraulic Motor

A novel, variable displacement, low-speed high-torque hydraulic motor is being developed that is expected to be highly efficient across a broad operating range. To ensure the final hardware achieves the expected performance, the models used in the development of the motor must be experimentally validated and revised. The focus of this work is on mechanical energy loss models that were used to guide the design of a single-cylinder motor prototype and then experimental tests used for validation. Losses were modeled and organized into five primary groups: main shaft bearings, main shaft seal, case windage, valve actuation, and linkage losses. The single-cylinder prototype was fabricated, and test parameters were defined. Two test rigs were designed and built to capture losses of the motor experimentally; one was used to collect low torque, zero/low-pressure differential results, and the other used to collect high torque, high-pressure differential results. A staged assembly procedure was developed to capture the independent contributions of each loss. By reviewing the quality of correlation between test observations and model predictions and revising the model when necessary, the models were validated. The correlation was improved by reviewing and modifying model inputs. This allows future solutions to be more accurately predicted in the design phase to drive the design of better machines. The validated model package was able to predict the motor performance within an acceptable range of error.

Physical–Chemical Exfoliation of n-Alkylamine Derivatives of Layered Perovskite-like Oxide H2K0.5Bi2.5Ti4O13 into Nanosheets

In the present work, we report the results on exfoliation and coating formation of inorganic–organic hybrids based on the layered perovskite-like bismuth titanate H2K0.5Bi2.5Ti4O13·H2O that could be prepared by a simple ion exchange reaction from a Ruddlesden–Popper phase K2.5Bi2.5Ti4O13. The inorganic–organic hybrids were synthesized by intercalation reactions. Exfoliation into nanosheets was performed for the starting hydrated protonated titanate and for the derivatives intercalated by n-alkylamines to study the influence of preliminary intercalation on exfoliation efficiency. The selected precursors were exfoliated in aqueous solutions of tetrabutylammonium hydroxide using facile stirring and ultrasonication. The suspensions of nanosheets obtained were characterized using UV–vis spectrophotometry, dynamic light scattering, inductively coupled plasma spectroscopy, and gravimetry. Nanosheets were coated on preliminarily polyethyleneimine-covered Si substrates using a self-assembly procedure and studied using atomic force and scanning electron microscopy.

Tracing Eukaryotic Ribosome Biogenesis Factors Into the Archaeal Domain Sheds Light on the Evolution of Functional Complexity

Ribosome assembly is an essential and carefully choreographed cellular process. In eukaryotes, several 100 proteins, distributed across the nucleolus, nucleus, and cytoplasm, co-ordinate the step-wise assembly of four ribosomal RNAs (rRNAs) and approximately 80 ribosomal proteins (RPs) into the mature ribosomal subunits. Due to the inherent complexity of the assembly process, functional studies identifying ribosome biogenesis factors and, more importantly, their precise functions and interplay are confined to a few and very well-established model organisms. Although best characterized in yeast (Saccharomyces cerevisiae), emerging links to disease and the discovery of additional layers of regulation have recently encouraged deeper analysis of the pathway in human cells. In archaea, ribosome biogenesis is less well-understood. However, their simpler sub-cellular structure should allow a less elaborated assembly procedure, potentially providing insights into the functional essentials of ribosome biogenesis that evolved long before the diversification of archaea and eukaryotes. Here, we use a comprehensive phylogenetic profiling setup, integrating targeted ortholog searches with automated scoring of protein domain architecture similarities and an assessment of when search sensitivity becomes limiting, to trace 301 curated eukaryotic ribosome biogenesis factors across 982 taxa spanning the tree of life and including 727 archaea. We show that both factor loss and lineage-specific modifications of factor function modulate ribosome biogenesis, and we highlight that limited sensitivity of the ortholog search can confound evolutionary conclusions. Projecting into the archaeal domain, we find that only few factors are consistently present across the analyzed taxa, and lineage-specific loss is common. While members of the Asgard group are not special with respect to their inventory of ribosome biogenesis factors (RBFs), they unite the highest number of orthologs to eukaryotic RBFs in one taxon. Using large ribosomal subunit maturation as an example, we demonstrate that archaea pursue a simplified version of the corresponding steps in eukaryotes. Much of the complexity of this process evolved on the eukaryotic lineage by the duplication of ribosomal proteins and their subsequent functional diversification into ribosome biogenesis factors. This highlights that studying ribosome biogenesis in archaea provides fundamental information also for understanding the process in eukaryotes.

Electrical & Optical Double Barrier Qualification and Implementation on FENJA Electrically Trace Heated Pipe-in-Pipe Project

This paper provides an overview of the work completed to design, qualify, manufacture and integrate electrical and optical double barrier penetrators with the Electrically Trace Heated Pipe-in-Pipe (ETH-PiP) as part of the Neptune Energy Fenja Development Project. Typical subsea penetrator systems in the oil and gas industry, such as pumps, compressors and X-trees are designed to be retrievable, to enable periodic refurbishment as well as providing the option for replacement, if required. However, the ETH-PiP architecture makes retrieval of system components complicated and uneconomical. Both the electrical and optical dual barrier penetrator system designs have to comply with a set of ETH-PiP specific criteria, such as to be maintenance free over a 25 years service life, prevent water ingress to the pipeline, provide pressure containment for operational media (in an unlikely scenario where the inner pipe bursts) and guarantee minimum footprint to allow an optimum integration onto the Pipeline End Termination (PLET) structure. In addition, the electrical system has to comply with a medium voltage rating (i.e. 5.0/8.7kV) to ensure a wide range of possible ETH-PiP architectures. The optical system has to maintain insertion loss below 0.5dB and a back reflection below -45dB to comply with the stringent requirements of distributed temperature monitoring sensor system over long distances. The qualification program of the electrical dual barrier penetrator system was performed in accordance with IEC 60502-4 and SEPS-SP-1001. A tailor made sequence had to be developed for the optical system, based on guidance from SEAFOM-TSD-01, considering that the system partly falls outside the associated standard application. The electrical dual barrier penetrator system qualification sequence was developed in two phases; firstly, the electrical transition contacts in the feedthrough chamber were qualified in accordance with IEC 60502-4 and secondly, four electrical double barrier penetrator prototypes were manufactured to allow the completion of the qualification sequence defined as per SEPS-SP-1001. The optical dual barrier penetrator system qualification employed the manufacturing of three prototypes to execute the pre-defined qualification sequence. Following the individual qualification of the electrical and optical dual barrier penetrator systems, subsequent welding and full-scale assembly trials were performed to ensure that the maximum allowable temperatures within the penetrators would not be exceeded during welding to the PLET, and to proof test the assembly procedure. Electrical verification testing was also undertaken during these trials to verify that the integrity of the penetrators had been maintained during the assembly and that the PLET arrangement did not give rise to any electrical stresses that could result in excessive deterioration of the penetrators. Integration of the four electrical and two optical dual barrier penetrator systems to the project PLET was completed in Q1 2020, with the actual subsea installation of the first ETH-PiP section including the PLET in Q3 2020.

Microscale 3D Printed Patterns for Nanoscale Particle Assembly

Directed particle assembly has broad applications in sensors, actuators, microelectronics, robotics, and the biomedical area. Currently available methods include external fields such as electrical or magnetic fields, surface treatment on substrates, and DNA-assisted templates. However, these methods are most efficient at the nanoscale and would lose their efficiency and scalability above microscales. We reported in this research the uses of the 3D printed surface to direct the assembly of nanoparticles. We used carbon nanofibers (CNFs) as an example to show the long-range orders after dipping the 3D printed substrates in CNFs suspensions. The anchoring of CNFs at the solid-liquid-air contact lines will initiate the assembly procedure and further induced the neighboring CNFs because of the van der Waals forces. As a result, the CNFs formed well-regulated bands with controlled spacing and close-packing. These assembled CNFs were demonstrated in sensing applications. A gauge factor regulated the methanol at different concentrations and temperatures to pass the sensor, with the device resistivity change. In this way, the sensitivity as a function of analyte concentration and temperatures was obtained. This research studied nanoparticles’ microscale assembly based on a simple 3D printing surface and shed light on a new hybrid manufacturing for nanoparticle assembly.

Comparative evaluation of WIMP and immersive natural finger interaction: a user study on CAD assembly modeling

Virtual and augmented reality allows the utilization of natural user interfaces, such as realistic finger interaction, even for purposes that were previously dominated by the WIMP paradigm. This new form of interaction is particularly suitable for applications involving manipulation tasks in 3D space, such as CAD assembly modeling. The objective of this paper is to evaluate the suitability of natural interaction for CAD assembly modeling in virtual reality. An advantage of the natural interaction compared to the conventional operation by computer mouse would indicate development potential for user interfaces of current CAD applications. Our approach bases on two main elements. Firstly, a novel natural user interface for realistic finger interaction enables the user to interact with virtual objects similar to physical ones. Secondly, an algorithm automatically detects constraints between CAD components based solely on their geometry and spatial location. In order to prove the usability of the natural CAD assembly modeling approach in comparison with the assembly procedure in current WIMP operated CAD software, we present a comparative user study. Results show that the VR method including natural finger interaction significantly outperforms the desktop-based CAD application in terms of efficiency and ease of use.