Permanent Structure Research Articles

A Noncovalent π-Stacked Dual-Pore Molecular Crystal for Ethanol/Water and Benzene/Methanol Azeotrope Separation.

Separation of ethanol/water or benzene/methanol azeotrope mixtures presents significant challenges, not only due to the limitations of conventional distillation techniques but also because of the constraints in developing and utilizing of new generation adsorbents. Porous organic molecular frameworks constructed via noncovalent π-interactions are emerging as novel adsorbents with vast potential in gas adsorption and molecular separation. Herein, we report a permanent two-dimensional porous structure, namely TDTBA-1, which consists of two different kinds of pores through π-stacking of a single organic molecule with highlyTdsymmetry. Activated TDTBA-1 exhibits excellent hydrophobicity, thermal stability, recoverability and high selectivity for ethanol over water, and benzene over methanol. Therefore, activated TDTBA-1 can be used as an efficient stationary phase for the separation of ethanol/water and benzene/methanol azeotropes by high-resolution gas chromatography.

Removal of polyphenols from anthocyanin-rich extracts using 4-vinylpyridine crosslinked copolymers

In this work, new sorbents for the purification of anthocyanin-rich extracts were evaluated. Copolymers of 4-vinylpyridine crosslinked with trimethylolpropane trimethacrylate (poly(4VP-co-TRIM)) or 1,4-dimethacryloyloxybenzene (poly(4VP-co-14DMB)) were tested for their potential to capture polyphenols. Copolymers were obtained by seed swelling polymerization in the form of microspheres with permanent porous structure – attractive features of sorbents used for sample purification by dispersive solid phase extraction. The microspheres were characterized by AFM, elemental analysis, SEM, and nitrogen adsorption-desorption method. Their capacity to remove polyphenols was evaluated using spectrophotometry, HPLC-DAD, and LC-MS/MS. For proof-of-concept, the aqueous extracts of berries classified into three different groups regarding their anthocyanin composition (strawberries, raspberries, blackcurrants) were selected. It was found that studied microspheres adsorbed flavonoids more effectively compared to primary secondary amine and graphitized carbon black. Copolymers of 4-vinylpyridine also capture anthocyanins and might be used for the purification of extracts of fruits before LC-MS/MS analysis to reduce the matrix effect.

A New Zero Waste Design for a Manufacturing Approach for Direct-Drive Wind Turbine Electrical Generator Structural Components

An integrated structural optimization strategy was produced in this study for direct-drive electrical generator structures of offshore wind turbines, implementing a design for an additive manufacturing approach, and using generative design techniques. Direct-drive configurations are widely implemented on offshore wind energy systems due to their high efficiency, reliability, and structural simplicity. However, the greatest challenge associated with these types of machines is the structural optimization of the electrical generator due to the demanding operating conditions. An integrated structural optimization strategy was developed to assess a 100-kW permanent magnet direct-drive generator structure. Generated topologies were evaluated by performing finite element analyses and a metal additive manufacturing process simulation. This novel approach assembles a vast amount of structural information to produce a fit-for-purpose, adaptative, optimization strategy, combining data from static structural analyses, modal analyses, and manufacturing analyses to automatically generate an efficient model through a generative iterative process. The results obtained in this study demonstrate the importance of developing an integrated structural optimization strategy at an early phase of a large-scale project. By considering the typical working condition loads and the machine’s dynamic behavior through the structure’s natural frequencies during the optimization process coupled with a design for an additive manufacturing approach, the operational range of the wind turbine was maximized, the overall costs were reduced, and production times were significantly diminished. Integrating the constraints associated with the additive manufacturing process into the design stage produced high-efficiency results with over 23% in weight reduction when compared with conventional structural optimization techniques.

Starting continuous improvement; creating a common understanding of stroke care delivery in a general hospital

BackgroundContinuous improvement is based on fostering practitioners’ suggestions to modify their own work processes This improvement strategy is widely applied in healthcare but difficult to maintain. The cross-disciplinary nature of many care processes constitutes an extra impediment.MethodsThe study had an explorative design with a qualitative single-case approach. The case presents a project to improve the treatment of patients with thrombotic stroke. Data was obtained via hands on involvement, documents, observations, and interviews with participants in a cross-functional improvement group. A thematic analysis method was employed.ResultsThrough learning how tasks were carried out in other disciplines, the participants developed a common understanding of why it took so long to provide treatment to stroke patients. These insights were used to implement practical changes, leading to immediate improvements in stroke care delivery. The results were fed back so that successes became visible. Participants’ understandings of the local context enabled them to convince peers of the rationale of changes, setting in motion a permanent improvement structure. The participants considered that mapping and then assessing the entire workflow across disciplines were relevant methods for improving the quality of patient care.ConclusionStarting an improvement project in a cross disciplinary environment requires deep engagement on the part of professionals. A quintessential prerequisite is therefore the realization that the quality of care depends on cross-disciplinary cooperation. A facilitated learning arena needs to (1) create insights into each other’s colleagues’ tasks and process interdependencies, (2) increase understanding of how the distribution of tasks among specialist units affects the quality of care, and (3) frequently report and provide feedback on results to keep the process going.

A wall climbing robot based on machine vision for automatic welding seam inspection

With the ongoing progress of industrial technology such as shipbuilding, the importance of weld quality in industrial production is becoming increasingly prominent. Intelligent and automated welding seam inspection robots are more efficient than traditional manual inspection and can avoid dangerous accidents. This article describes the design of a welding seam inspection robot suitable for high-altitude ship operation. The robot uses machine vision and object segmentation models to automatically detect the position of welding seams, and uses a cubic polynomial to fit the welding seam path. The upper and lower computers of the robot communicate through WIFI transmission and TCP protocol, which can realize remote real-time detection of weld surface defects. In addition, this article designs a permanent magnet adsorption structure for robot high-altitude wall climbing, which has been verified through simulation and experimental verification. To verify the intelligence of the robot, this paper conducted performance analysis experiments on weld line recognition and tracking models and surface defect models. The experimental results showed that the average detection accuracy of the weld line recognition and tracking algorithm was 96.8%, and the average detection accuracy of surface defects in the three types of welds was 94.2%. The method proposed in this article combines two algorithms and a special robot structure, providing a new approach for the automated inspection of welds in large industrial products such as ships.

The design elements of outpatient geriatric rehabilitation from patient, healthcare professional, and organizational perspective; a qualitative study

Purpose To gain a rich understanding of the experiences and opinions of patients, healthcare professionals, and policymakers regarding the design of OGR with structure, process, environment, and outcome components. Methods Qualitative research based on the constructive grounded theory approach is performed. Semi-structured interviews were conducted with patients who received OGR (n = 13), two focus groups with healthcare professionals (n = 13), and one focus group with policymakers (n = 4). The Post-acute Care Rehabilitation quality framework was used as a theoretical background in all research steps. Results The data analysis of all perspectives resulted in seven themes: the outcome of OGR focuses on the patient’s independence and regaining control over their functioning at home. Essential process elements are a patient-oriented network, a well-coordinated dedicated team at home, and blended eHealth applications. Additionally, closer cooperation in integrated care and refinement regarding financial, time-management, and technological challenges is needed with implementation into a permanent structure. All steps should be influenced by the stimulating aspect of the physical and social rehabilitation environment. Conclusion The three perspectives generally complement each other to regain patients’ quality of life and autonomy. This study demonstrates an overview of the building blocks that can be used in developing and designing an OGR trajectory.

Porous triptycene network nanofilms with high molecular sieving accuracy for antibiotics separation

For antibiotics, the purification and separation in the synthesis process, as well as enrichment and recycling in the utilization process, has a profound impact on human health and environmental issues, which pose an unignorable challenge for selective molecular sieving of separation technology. Herein, we offered a convenient high-accuracy separation membrane construction by using three dimensional rigid triptycenes as building-blocks to fabricate porous triptycene networks polyarylate nanofilms (PTN-NFs) by interfacial polymerization. With permanent porous structure and excellent stability, the PTN-NF membrane exhibited remarkable separation precision around 90 g mol−1 scale for several mixture separation and significant selectivity as high as 39.3 for piperacillin/6-aminopenicillanic acid (6-APA) separation.

Podejście oparte na GIS analizie do relacji między jednostkami gruntów a użytkowaniem gruntów w centralnym regionie Portugalii

Land units refer to coherent spatial areas characterized by a degree of homogeneity concerning certain properties like geology, soils, and climate. The Land use mosaic corresponds to a circumstantial layer representing the landscape’s present state, depicting the present resource allocation factors. Nevertheless, the stable potential layer is related to the stable characteristics of each site and allows the identification of use constraints or potentials. In this study, we use a methodology based on the land unit concept to define a stable potential layer at a regional level. Therefore, land units were delimited for the Central region of Portugal, resulting from the combination of geomorphology, soil parent material, and bioclimatic influence. For each land unit representative sample areas were characterized in terms of their land use mosaic characteristics. For that purpose, selected landscape metrics were used to quantify the land use mosaic geometrical attributes: Shannon’s Diversity Index, Edge Density, Mean Patch Size, and Number of Patches. The existing land use types were also quantified. Finally, a cluster analysis was performed to define groups of samples representing the land units with similar land-use mosaic types. The landscape metrics that best explain the influence of the permanent structure of the territory on the circumstantial structure of use are Shannon's Diversity Index, Edge Density, and Number of Patches. The highest diversity land cover patterns are located in formations with a lithology rich to very rich in silica under Mesomediterranean dry to subhumid climate. The validation of the previously defined land units confirmed the reliability of the proposed methodology, with most of the land units strongly influencing the land use mosaic. The delimitation and characterization of homogeneous land units are useful for the definition of soil suitability and for the choice of the most appropriate uses and activities by the stakeholders.

Algorithm for determining tensions in a stay cable with a manufacturing defect

Purpose. Establishing the influence of presence of a longitudinal area, on which there is detachment of layers over a limited length of a composite orthotropic rope, on its stress-strain state. Research methodology. Development of a method for calculating the influence of presence of a longitudinal area, on which there is detachment of layers over a limited length of a composite orthotropic rope, on its stress-strain state by constructing and analytically solving a model of a stress-strain state of a composite tractive element, considering the conditions of interaction of a rope with a permanent structure using the methods of mechanics of layered composite materials with soft and hard layers. Findings. Analytical dependencies are obtained in a closed form, which allow determining a stress-strain state of a composite multi-layer rope with partial local detachment of a separate layer, considering the breakage of one reinforcing element. An algorithm for determining a stress-strain state of a composite multi-layer rope with partial detachment of a separate layer considering the breakage of one reinforcing element is established. Characteristics of a dependency of unevenness coefficients of load distribution in reinforcing elements, displacements and shear angle tangents on the ordinal number of a damaged cable in a presence of partial local detachment of a separate layer of a composite stay rope is established. Scientific novelty. Influence character of presence of a longitudinal area, on which there is detachment of layers over a limited length of a composite orthotropic rope, on its stress-strain state is established. A method of calculating the influence of presence of an area of detached layers in a rope on its stress-strain state is developed. Practical significance. Local detachment of layers is possible in a process of producing a composite multi-layer stay rope. The developed algorithm makes it possible to determine a stress-strain state of composite stay rope with local layer detachment. The known values of detachment allow implementing justified engineering solutions regarding the conditions of safe, temporary use of a composite rope in cable-stayed structure.

The Use of Up-to Date Analyses for the Temporary Bridges Application in the Present

Abstract Bridges are a critical element of the transport network. In case of neglected maintenance, war conflict or natural disaster, they may be damaged or destroyed. An alternative solution in the form of a detour is mostly feasible only in the case of ground communication. But even in this case, it can be a very difficult and lengthy solution. Therefore, temporary bridges are often used to replace the permanent bridge structure for a certain time. The history of temporary bridges is essentially as old as that of permanent bridges. The first patented temporary bridge was the Eifel Bridge, which had a span of up to 60.0 m in 1888. Before the Second World War, the most widespread structures were the German S-bridge with spans of up to 15.0 m, Herbert-brücke with a span of up to 25.0 m and the English Bailey bridge system. In the post-war era, the ŽM 60 temporary bridge was designed as a universal bridge structure, which was to serve to temporarily bridge obstacles of medium and long spans. As standard, it was to serve as a railway bridge with a span of up to 60.0 m and as a road bridge with a span of 84.0 m. The task of the study published in this paper is to approach the possibilities of deploying the ŽM 60 bridge at present in compliance with the requirements arising from currently applicable standards and regulations.

Desorption and migration of dissolved organics from oil sands tailings to capped water: Demonstration pit lake

Rate and mechanism of organic compounds desorption from fluid fine tailings (FFT) deposits into the capped water are crucial to understand the geochemical stability of end pit lakes. Specifically, the intricate interplay between electrolyte concentrations and seasonal fluctuations along with their impact on the persistence of organic constituents remains insufficiently elucidated. This study utilized PASS-treated FFT (i.e., permanent aquatic structure storage) from Lake Miwasin to address these questions. Experiments were conducted to investigate the desorption of organics from FFT into lake water under different conditions, including FFT dosage, contact time, temperature, and ionic strength. Results revealed that higher FFT dosage and lake water organic matter led to increased desorption of dissolved organic carbon (DOC), while temperature and conductivity of the lake water had minimal effects. The presence of electrolytes regulated the equilibrium desorption capacity of DOC, with cations (K+ and Ca2+) significantly affecting the desorption process from negatively charged treated FFT particles. Temkin isotherms displayed that desorption dynamics followed physically favorable patterns whereas the Intraparticle diffusion kinetic model suggested the equilibrium desorption capacity of DOC as 0.65 mg/g of PASS-treated FFT. A small percentage (5.82 %) of the DOC and less than half of naphthenic acids (NAs) (39.1 %) in PASS-treated FFT were potentially released. The distribution coefficient value of DOC and NAs was comparably high, indicating that DOC and NAs were mostly stable within the PASS-treated FFT deposition. The study reflects considerable stability of PASS-treated FFT about the physical and chemical conditions of the lake water, making them a promising alternative in FFT management.

LITERACY IN A MULTIGRADE CLASS IN A RURAL SCHOOL

This paper shows results of a study carried out with a multigrade class in a rural school and focuses on a literacy teacher’s pedagogical work organization. The discussion emphasizes how the teacher – by means of a planning structure – develops activities considering heterogeneity as a factor that contributes to both teaching and learning processes. Data were collected of participatory observation and video and audio recordings which were transcribed and subject to the Content Analysis (Bardin, 2016). Results showed a permanent structure of connected pedagogical activities by means of students’ collective and individual organization in order to ensure that they learn how to read and write inclusively. Data trigger reflections upon the relevance of systematic pedagogical proposals as a possibility of structuring the literacy process while respecting heterogeneity of learning processes.

Electromagnetic Characterization of Permanent Magnet Eddy Current Structures Based on Backplane Distance Adjustment

To address the problem of problematic spray design inside mining anchor-digging equipment, a switching seal using a permanent magnet eddy current drive is initially presented here. The layer model of the permanent magnet eddy current structure is established, the subdomain analysis model is introduced, the permanent magnet eddy current structure is divided into six regions along the axial direction, and the boundary equations are established at the interfaces of each region. The vector magnetic potential equations in each region are deduced, along with the electromagnetic torque and axial force equations. The computational results are compared and analyzed with the results of finite element simulation, verifying the accuracy of the theoretical model. The design of experiments is used to verify the feasibility of the switching seal using the permanent magnet eddy current structure.

Magnetic field density concentrated permanent magnet structure for electromagnetic MEMS scanning mirror

The study investigates the inadequacy of driving torque in large-diameter Micro-electro Mechanical Systems Electromagnetic Scanning Mirrors (MEMS-ESM) and introduces fresh insights into the power efficiency of traditional MEMS-ESM devices. A novel permanent magnet structure (PMS) and driving principle are devised, drawing upon the phenomenon of concentrated magnetic field density and a custom-designed PMS inner profile. In comparison to L-shaped and I-shaped PMSs, the proposed PMS delivers up to 3.48 times and 3.76 times greater driving torque within the same form factor. Moreover, the optimized proposed PMS has been experimentally proven to reduce power consumption by 53.3% and 81.4% and reduce total driving current by 31.3% and 55.0%, making it the sole solution that conforms to the safe current range. Additionally, the research analyzes the impact of variations in the optical scanning angle on the optimal PMS design. It is noteworthy that the proposed PMS enables the substitution of L-type and I-type PMSs with smaller package sizes, all while preserving torque, thus promoting the miniaturization of MEMS-SM.

Analysis of Covered Pile on Multi-row Pile Quay

The multi-row pile quay wall is an innovative permanent structure comprising multiple piles, relieving slabs, flood control walls, and backfill sand. Although it additionally serves as a functional wharf, the research on multi-row pile quay walls remains insufficient. Considering the Changxing harbor Pool as a case study, this research develops a multi-row pile quay wall structure using the three-dimensional finite element software PLAXIS 3D. We investigated the effects of covered piles, pile row spacing, spacing between covered piles, and the stiffness of the front pile on the internal force and deformation of the structure. The findings indicated that the presence of the covered piles results in minimal overall displacement of the multi-row pile quay wall and reduces the bending moment in the front pile. Considering the site conditions and project costs, the sensitivity of different parameters to the retaining effect was evaluated in the order of the stiffness of the front pile > pile row spacing > spacing between the covered piles. Building on this, an optimized design scheme is proposed to reduce the bending moment in the front pile by 50% compared to the original scheme, thereby offering valuable insights for future engineering projects.

Ultrahigh-Efficient N,O-Functionalized covalent organic framework towards thorium adsorption from uranium and rare earth elements

The development of novel porous materials as adsorbents for highly effective separation of thorium from ore or nuclear wastewater co-existing with uranium and rare earth elements is one of the most desirable methods but remains challenging. In this work, we prepare a N,O-functionalized two-dimensional covalent organic framework (2D COF), namely TAPT-DHTA, with a permanent porous structure and plenty of nitrogen and oxygen adsorption sites throughout the skeletons, which displays an ultrahigh Th(IV) saturated adsorption capacity of 1394 mg g−1 (at pH = 4.0), higher than all adsorbents reported so far. Moreover, the TAPT-DHTA COF has a large distribution coefficient (Kd) of up to 5.2 × 104 mL g−1, implying its extremely strong affinity for Th(IV) due to the collaborative coordination interactions between N/O atoms and Th(IV) as well as their specific binding mechanism. The distinguished adsorption behavior of the TAPT-DHTA COF affords an important platform for highly selective separation of Th(IV) from uranium and rare earth elements, thereby shedding some light on the design of novel adsorbents for thorium separation in the thorium fuel cycle.

The engineering legacy of the FIFA World Cup Qatar 2022TM: Al Thumama Stadium

The structures of the Al Thumama Stadium, built for the FIFA World Cup Qatar 2022, can be categorised into four main building components. The permanent bowl structure with lower and middle tiers is mainly cast-in-place reinforced concrete with precast seating units. Structural steel was used for the upper tier stands, to be dismantled for legacy conversion after the tournament. The roof and façade system use steel and cable systems with a unique membrane cladding design derived from the cultural gahfiya symbol. The roof is a self-anchored tension–compression ring system based on the principle of a horizontal spoked wheel, with one compression ring along the outer perimeter and two tension rings along the oculus. The façade consists of lightweight double-layered and prestressed cable nets spanning between curved vertical beams. A translucent polytetrafluoroethylene-coated glass fibre membrane with highly transparent mesh inserts form the cladding of the stadium, providing its unique architectural design. This article gives an overview of the stadium's design and construction methodology.

Design and characterization of 3D printed pore gradient hydrogel scaffold for bone tissue engineering

Macroporous hydrogel scaffolds are widely used in tissue engineering to promote cell growth and proliferation. Aiming to enhance cell seeding efficiency and facilitate the osteodifferentiation of mesenchymal stem cells, this study demonstrates the fabrication of pore gradient biodegradable hydrogel scaffolds inspired by natural bone structure for bone tissue engineering applications. The scaffolds were fabricated via extrusion-based 3D printing, using sequential deposition of three customized Gelatin/Oxidized Alginate - based inks with subsequent cryogenic crosslinking for permanent structure fixation. The resulting constructs were characterized and featured a continuous gradient morphology with pore sizes ranging from 10 to 300 μm. The gradient scaffolds exhibited improved mechanical stability, with a compression resistance of 149 kPa, as opposed to the non-gradient scaffold's 116 kPa at 70 % strain, and a sustained degradation rate with only a 10 % loss of its initial weight within three weeks. Gradient scaffolds demonstrated a doubling of cell seeding efficiency to 47 % with dense and homogeneously distributed cellular layers, as evidenced by confocal and electron microscopy. Furthermore, the gradient scaffolds demonstrated superior osteodifferentiation, with significantly higher ALP and DMP1 production and enhanced extracellular matrix mineralization compared to gradientless macroporous scaffolds. This study provides insights into the design of macroporous scaffolds and emphasizes the advantages of pore gradient over homogeneous gradientless morphologies.

Strengthening data integrity in academic document recording with blockchain and InterPlanetary file system

A diploma is a certificate or official document given by a school or college that is useful for continuing education, applying for jobs, and assessing student intelligence. The main problem with diplomas and other academic documents is that many are forged. This study aims to develop a prototype for recording student academic data using blockchain and blockchain and InterPlanetary file system (IPFS). The research stages were conducted with system conceptualization, data modeling, smart contract development, IPFS integration, data transaction development, user interface/user experience (UI/UX) development, and system testing. A blockchain is a permanent information structure formed by data blocks that are interconnected with transaction data blocks before and after it. The transaction data for each block are encrypted using asymmetric cryptography. IPFS is a peer-to-peer network protocol for storing and sharing data in a distributed file system applying the concept of decentralization to make the manipulation more difficult. The results show that student academic data and documents were successfully stored in a blockchain network using smart contracts and IPFS. Blockchain technology, smart contracts, and IPFS strengthen the value of these documents into documents that are safe, difficult to counterfeit, and easy to trace, such that authentication and integration are better preserved.

Conceptual design of DEMO breeding blanket in-vessel toroidal transporter

The development of a viable maintenance strategy for the replacement of the Breeding Blanket (BB) segments of DEMO is a key aspect in the way for fusion energy. Previous work concerned the development of a BB vertical transporter to lift, tilt and handle the BB segment inside the remote handling (RH) ports. A potential solution for the replacement of the BB segments could consist in lifting all BB segments from four RH ports, by mean of BB vertical transporter coupled with a BB toroidal in-vessel transporter avoiding the opening of the remaining ports during maintenance. In this way, the activities concerning the removal and re-installation of the auxiliary components (BB feeding pipes, permanent structure for pipes handling, closure plate, port plug, etc.) inside the non-remote handling ports will be avoided, having a strong impact on the reduction of the remote maintenance times and hence on the overall availability of the machine. To assure the feasibility of the proposed strategy a dedicated tool, capable to move toroidally the huge BB segments, shall be developed. The main function of the tool will consist in lifting and toroidal translation of the BB segments that have to be aligned to the RH port, where they will be grabbed and lifted by the BB vertical transporter. The work here presented focuses on the conceptual design of a toroidal transporter to lift and toroidally translate the BB segments inside the Vacuum Vessel. The conceptual design of the BB Toroidal Transporter (BBTT) was developed to handle both the inboard and the outboard segments; a foldable lower foot, equipped with toroidal trucks and suspension system, has been designed to withstand the assumed loads and seismic loads. Preliminary FEM analysis has been carried out to check the structural integrity of the proposed design.