Wall Protection Research Articles

Common Faults Prevention of Autoclaved Aerated Concrete Block Masonry

Autoclaved aerated concrete block (AACB) is a new kind of green, environmental protection and economical wall material. Its production process can absorb a large amount of industrial waste residue, and the ratio of raw materials can reach more than 70%. However, in the actual construction situation, crack problems such as wall cracking and plaster layer falling off, as well as quality problems such as insufficient strength and easy cracking occur from time to time in the masonry which using AACB. In this paper, the common faults and causes of AACB masonry are summarized and analyzed, moreover, the related prevention and solving measures are put forward for reference in the masonry engineering. This paper can provide reference for the construction specification and quality acceptance of masonry engineering.

Informatization of Accounting Systems in Small- and Medium-Sized Enterprises Based on Artificial Intelligence-Enabled Cloud Computing.

Against the backdrop of China's growing market economy, small- and medium-sized enterprises (SMEs) have taken advantage of this opportunity to develop rapidly. At present, SMEs have become an important part of the market economy. Accounting system information management system is an advanced form of management, and improving the degree of accounting information is the key to improving the management mode of SMEs. This study applies cloud computing to enterprise accounting management systems. The results show that realizing SME accounting information management can effectively improve economic settlements. With the development of cloud computing, its improvement of accounting management efficiency cannot be ignored. Besides, the risks of accounting informatization, enterprises can make their development by establishing a secure network protection wall and relying on strict relevant laws and regulations.

Performance evaluation of fuel indirect cooling based thermal management system using liquid metal for hydrocarbon-fueled scramjet

Hydrocarbon-fueled scramjet is one of the most promising air-breathing propulsion systems for hypersonic flight, but the wall thermal protection issue strictly limits its maximum flight Mach number. This study presents a fuel indirect cooling based thermal management system (TMS) scheme, in which a bypass heat-exchanger connected with closed-Brayton-cycle power generator in parallel for heat source and in series for cold source is applied for the full utilization of fuel's heat absorption capacity. Results obtained by a fuel indirect cooling based TMS coupling model indicate that this TMS has an excellent performance on combustor wall protection, and the highest temperature of combustor wall is no more than 1325.00 K at the heat flux density with maximum value of nearly 5.49 MW/m2. Improving inlet temperature of wall cooling channel (Tlm1) is beneficial to avoid pinch point issue and reduce size for bypass heat-exchanger. In addition, in the view of combustor wall thermal protection, the upper limit of Ma for hydrocarbon-fueled scramjet can reach 9 theoretically, when the fuel indirect cooling based TMS with Tlm1 of 1023 K is employed. This research provides an innovative solution in the wall thermal protection and heat dissipation utilization for hydrocarbon-fueled scramjets at high Mach numbers.

Seeking Ways for Dealing with the Impacts of Sandstorms on the Railway Network in Saudi Arabia

Sandstorms that cause shifting dunes are a huge technical challenge in the development of the railway network in Saudi Arabia, and are known as one of the most concerning atmospheric aspects. In this case, the weather or climate change makes railways more problematic and costly in Saudi Arabia compared to other countries. The purpose of this article is to develop Saudi Arabia’s rail system in order to overcome environmental difficulties and obstacles such as wind–sand flow behavior and other impediments (e.g., camels) by constructing obstructions such as protective walls and dykes. Theoretical analysis is used to investigate the major components that influence wind velocity and density. The wind velocity in the majority of the locations in Saudi Arabia was employed as a control value in this study, which was based on the Saudi building standard SBC301. Sandstorm protection is best achieved by combining four different building solutions, including ditches, dykes, trees, and concrete barriers. The site parameters, such as sand particle size, air velocity, and the required downwind strip distance, all influence which of the four recommended approaches is optimal. From this study, it is concluded that the wind speed at the height of interest (barrier height) should be calculated using wind shear exponents ranging from 0.2 to 0.5 depending on the topography and surface roughness aspects. A new equation based on two parameters, Q1 and n, as a function of the wind shear exponent is suggested to predict the percentage of wind velocity increase (Vinc %) over the barriers. This study found that the protected distance between the downwind strip and the receiver might be anywhere between 20 and 40 m.

My Mind Was a Military Sky

My Mind Was a Military Sky

Lowering water level in an excavation for a multi-family residential building in urban development

The paper concerns lowering water level in excavations for residential buildings in a dense urban development. The construction and protection of excavation walls as well as the methods of lowering the water level and its impact on the surroundings were discussed. An excavation dewatering system is presented on the example of a multi-family residential building with one underground floor, built in dense urban development. The excavation executed in the sandy subsoil below the groundwater level and encased with walls made of steel sheet piles was analysed. Two concepts of lowering the water level in the excavation were considered: the first with use of a wellpoint system, the second with use of a well with pumps. The conducted calculations showed that when using a wellpoint system to lower the water level in the excavation for analysed multi-family residential building, a system consisting of 260 wellpoints with a spacing of 1.0 m should be made. The efficiency of a single wellpoint is 12.25 m3·d–1, and the efficiency of the entire installation is 3,185.69 m3·d–1. When draining the wells, a system consisting of 9 wells should be made, with a unit capacity of 375.58 m3·d–1 and efficiency of the total installation 3,380.22 m3·d–1.

A Research on Road and Bridge Detection Based on Test Detection Technology

The existence of karst cave at the bottom of bored piles has a great impact on projects under construction and the surrounding buildings. Since bored piles require slurry wall protection, the current geophysical exploration method cannot effectively detect the karst cave at the bottom of the piles in the slurry. Combined with the characteristics of stress wave propagation, the sonar detection method is proposed. JL sonar detector can realize the transmission and acquisition of on-site sonar signals. This method makes full use of the mud conditions of bored cast-in-place piles, and the development of karst caves can be tracked and detected within 10 meters at the pile bottom during the drilling process. It has several advantages, including low cost, high speed, and high precision. This paper verifies the application of sonar detection technology in practical engineering through specific engineering cases. The research results put forward a new solution for cave exploration in karst areas, especially in liquid environment.

Analysis of Seismic Isolation Performance of X-Shaped Rubber Bearings (XRBs)

A detailed analysis of the seismic safety performance of building structures using X-shaped rubber bearings (XRBs) under seismic action at different seismic levels of intensity were carried out in this study. The horizontal mechanical properties of XRB were studied by analytical methods. To reveal the failure prevention and control capability of XRBs under strong ground motions, a detailed comparative analysis was conducted of the seismic performances of three-story buildings using XRBs, typical rubber bearings (TRBs), and TRBs with retaining wall protection (RWP). A nonlinear dynamic finite element method was used to analyze the displacement, velocity, and acceleration responses of the seismically isolated structures at different ground motion intensity levels. The results show that the failure of the seismic isolation layer occurs in the building using TRBs under seismic intensity with a 1‱ probability of exceedance (PE) in one year. When the RWP is set around the seismic isolation layer, the superstructure will collide with the wall, which leads to a dramatic increase in superstructure acceleration, while the overall seismic isolation performance of the structure is affected. Nevertheless, XRBs can effectively prevent deformation failure of the seismic isolation layer of a building, reduce the seismic response of a superstructure, and can improve the seismic safety level of a building.

Alternatif Bahan Dinding Bata Tanah Putih yang Ditambah Sekam Padi yang Tidak Dibakar

Title: Unburned Rice Husk as an Alternative Additive in the Making of White Soil Brick Top soil structure in Kupang city and regency consist of white soil which contain 30-65% sand. This kind of soil is very potential as brick-making material. The experiments carried out turned out that white soil bricks with rice husks additive without going through the combustion process could reach a compressive strength of 100.9 kg/cm² at a ratio of 1 cement: 7 white soil: 1 rice husk. Without being burned to ashes, rice husks can strengthen white soil bricks. In a previous study, bricks without husk additive with a ratio of 1 cement: 7 white soil with a brick size of 24 x 11 x 6 only reached 51.9 kg/cm² (Bebhe et al., 2020). Meanwhile, in another experiment, white soil brick added with rice husk ash with a size of 23 x 11 x 5 cm could reach 114.3 kg/cm² (Bebhe & Daton, 2021). This proves that rice husks as additive material can increase the compressive strength of white soil bricks .The results of this experiment about compressive strength could exceed the compressive strength of grades 1 and 2 based on SNI 03-0349-1989. For loaded and unprotected wall construction, loaded and protected wall construction, and unencumbered and protected wall construction based on SNI 03-6881.1-2002. Keywords: white soil brick, rice husk, compressive strength, wall construction.

Tell el-Amarna, Autumn 2020 to Autumn 2021

Fieldwork at Amarna from autumn 2020 through autumn 2021 included a second season of excavation at the North Desert Cemetery, and the continuation of several post-excavation projects. Those reported on here are the preliminary study of skeletal materials and hair from the North Desert Cemetery itself, along with the ongoing study of textiles from the South Tombs and North Cliffs Cemeteries. Site management initiatives included the construction of two protective boundary walls at the north end of Amarna.

Transcriptome Analysis of Plenodomus tracheiphilus Infecting Rough Lemon (Citrus jambhiri Lush.) Indicates a Multifaceted Strategy during Host Pathogenesis.

Simple SummaryThe cultivation of the lemon is strongly impacted by mal secco, a disease that causes huge losses in yield every year. In this work, we have identified, retrieved, and classified genes that may play a crucial role in the onset and progression of the disease. Understanding the function of these genes will increase knowledge of the processes involving the mode of action of necrotrophic fungi during pathogenesis. Our results may be relevant to help identify sustainable field treatments to cope with disease diffusion and to provide direction into possible biotechnological approaches to generate resistant lemon plants.The causal agent of mal secco disease is the fungus Plenodomus tracheiphilus, mainly affecting lemon tree survival in the Mediterranean area. Using a fully compatible host-pathogen interaction, the aim of our work was to retrieve the fungus transcriptome by an RNA seq approach during infection of rough lemon (Citrus jambhiri Lush.) to identify crucial transcripts for pathogenesis establishment and progression. A total of 2438 clusters belonging to P. tracheiphilus were retrieved and classified into the GO and KEGG categories. Transcripts were categorized mainly within the “membrane”, “catalytic activity”, and “primary metabolic process” GO terms. Moreover, most of the transcripts are included in the “ribosome”, “carbon metabolism”, and “oxidative phosphorylation” KEGG categories. By focusing our attention on transcripts with FPKM values higher than the median, we were able to identify four main transcript groups functioning in (a) fungus cell wall remodeling and protection, (b) destroying plant defensive secondary metabolites, (c) optimizing fungus development and pathogenesis, and (d) toxin biosynthesis, thus indicating that a multifaceted strategy to subdue the host was executed.

Inter-machine plasma perturbation studies in EU-DEMO-relevant scenarios: lessons learnt for prediction of EM forces during VDEs

To support the deployment of the DEMO wall protection strategy, the development of comprehensive analyses is essential to understand the implications of transient perturbations on plasma shape control and on vertical stability, some of the most critical aspects to be considered in elongated plasmas. The design activities of the DEMO limiter structures require a deep understanding of the effects induced by transient plasma perturbations coupled with one of the most severe load conditions to occur in tokamaks, the vertical displacement event (VDE). Since electromagnetic (EM) loads during VDE phases are among the DEMO limiter’s design drivers, this study focuses on predictive simulations of the final plasma position and of EM loads following a VDE. For this purpose, a multi-tokamak study, supported by the construction of an inter-machine database containing experimental transient plasma perturbations and VDEs from JET and ASDEX Upgrade (AUG), has been carried out. It aims to characterize some transient plasma perturbations that may lead to high control efforts by the vertical stability system in terms of variations of the plasma’s internal parameters and vertical displacements. Consequently, such experimental transient plasma perturbations have been properly scaled to DEMO reference geometries with different magnetic configurations, to be simulated in terms of plasma dynamical behaviour by means of MAXFEA code. Finally, initial predictive EM loads on DEMO limiter structures are discussed in the case of VDEs following plasma perturbations.

Photoinduced Cross Linkable Polymerization of Flexible Perovskite Solar Cells and Modules by Incorporating Benzyl Acrylate

AbstractFlexible perovskite solar cells possess huge application potential in both outdoor (sunlight) and indoor scenes (artificial low light) owing to their high optoelectronic conversion efficiency and agile integration advantages. In order to further establish their feasibility to meet multi‐scenario applications, here a facile “internal packaging” interface strategy is developed, where a selective light‐cured cross‐linking molecule is leveraged to effectively heal the interface defects over perovskite films. Moreover, the cross‐linked interfacial layer can act as an airtight “protective wall”, preventing the device from water and oxygen corrosion and lead leakage. The flexible devices aided by this strategy show considerable performance ranging from small size to scalable modules (20.86%‐0.07 cm2, 16.75%‐24 cm2). More importantly, the optimal devices yield excellent moisture resistance, light soaking resistance, and lead leakage prevention stability. Based on the common light source environment of indoor scenes, the excellence of flexible modules (30.73% under white light‐emitting diode (LED), 26.48% under yellow LED) is further validated. It is expected that this gentle strategy can underline simultaneous promoting of the efficiency and stability of flexible perovskite modules, thereby accelerating the application of flexible perovskite in advanced industrial fields.

FFGA1 Protein Is Essential for Regulating Vegetative Growth, Cell Wall Integrity, and Protection against Stress in Flammunina filiformis.

Flammulina filiformis is a popular mushroom which has been regarded as a potential model fungus for mycelium growth, fruiting body development, and stress response studies. Based on a genome-wide search, four genes encoding heterotrimeric G protein α subunits were identified in F. filiformis. The data of conserved domain analysis showed that these genes contain only one subgroup I of Gα subunit (Gαi), similar to many other fungi. To explore the function of Gαi, FfGa1 over-expression (OE) and RNA interference (RNAi) strains were generated using the Agrobacterium tumefaciens-mediated transformation (ATMT) approach. RNAi transformant strains showed remarkably reduced growth on PDA medium and added sensitivity to cell wall-enforcing agents with maximum growth inhibition, but showed better growth in response to hypertonic stress-causing agents, while OE strains exhibited more resistance to thermal stress and mycoparasite Trichoderma as compared to the wild-type and RNAi strains. Taken together, our results indicated that FfGa1 positively regulates hyphal extension, and is crucial for the maintenance of cell wall integrity and protection against biotic and abiotic (hypertonic and thermal) stress.

Outbreak of Silicosis in Workers Producing Artificial Stone Skirting Boards: A Novel Application of Silica-Based Composites

Outbreak of Silicosis in Workers Producing Artificial Stone Skirting Boards: A Novel Application of Silica-Based Composites

Polypropylene Composite Material for Light Weight Fuel Tank Protection Shield

<div class="section abstract"><div class="htmlview paragraph">The fuel tank shield provides a protective boundary between the fuel tank and vehicle driveline in the event of a high-speed crash. Hence, it is important from the safety standpoint. The part must be carefully engineered to meet the challenging requirements in terms of stiffness, deflection, toughness, dimensional stability and thermal stability. In this paper, long glass fibre filled polypropylene material compound was selected and developed to meet the mentioned requirements for this part with significant mass reduction over other materials. The combination of material, optimized part and tool design led to weight savings and considerable cost reduction. This is a ready to mold material used in injection molding process.</div><div class="htmlview paragraph">This long glass fibre reinforced polypropylene compound has been explored for thin wall protection shield with wall thickness of 2.5 mm. This part has critical functional requirements such as driveline load versus deflection durability criteria, thermal stability, dimensional stability to overcome fouling and rattling with respect to interface parts, torque retention in mounting zones, gap and flush aspects. Structural durability of the design was validated by virtual engineering. Part design and material combinations with better tooling design iterations were analyzed by using mold flow analysis. Complete product performance was validated for predefined key test metrics such as structural durability, thermal aging, natural frequency, impact and torque retention. This part met the requirements. The combination of material, optimized part and tool design led to weight savings, balanced stiffness and toughness behavior, dimensional stability, and considerable cost reduction.</div></div>

Stability investigation of the flood protection structure at Nava Nakorn industrial estate, Thailand

A flood protection structure was built around the industrial area of Nava Nakorn in Pathum Thani Province, Thailand to ensure the safety of the industrial estate. Three types of flood protection walls were constructed and completed in 2012, which were prestress corrugated concrete sheet pile and reinforced concrete retaining wall. A large-scale experiment using a large navy watercraft for generating the water pressure on the flood protection structure was performed. Finite element analysis for simulation the flooding over 4 months was also performed. Factor of safety (FS) against external and internal failures decreased with increasing the flooding levels; however, all FS values were higher than the typical requirement for geotechnical design. All bending moments and shear stress in the flood protection walls were found to be lower than the required design values. The knowledge gained from this research can be applied to other flood walls, in similar soft clay deposits.

The Limits of the Law

AbstractThis paper scrutinizes the notion of the limits of the law by contrasting the narrative of the autonomy and independence of legal systems with the alternative narratives the law itself can acknowledge. If the limits of the law can dwell in this acknowledgment of alternative narratives, such limits will turn out to be neither reassuring borders nor protective walls. In the interstitial spaces between narratives may dwell a notion of limits of the law that probably cannot be captured by any geographic‐border metaphor.

Integrated design strategy for EU-DEMO first wall protection from plasma transients

This work presents an overview of the integrated strategy developed, as part of the DEMO Key Design Integration Issue 1 (KDII1), to protect the EU-DEMO first wall (FW) from planned and unplanned plasma transients by employing discrete limiters. The present Breeding Blanket (BB) FW design, which aims at minimizing the loss of neutrons while travelling to the breeding zone, is able to withstand steady state heat fluxes up to ≈1-1.5 MW/m² [1], which is not sufficient to guarantee its integrity for most plasma-FW direct contact. This is different from ITER, which has a FW designed for peak heat loads up to 4.6 MW/m2 [2], and it does not have the DEMO BB breeding related requirement. A series of documents was compiled in the DEMO Pre-Conceptual Design Phase, in support of the KDII1. The work presented here was presented at the 2020 DEMO Gate 1 (G1) review, and collects also the comments of the panel and the relative additional studies triggered by them. The design process, presented in this paper was adopted to systematically evaluate the impact of design changes, or new physics inputs, on the FW protection strategy and integration issues. It includes compiling the list of transients, and performing the relative plasma simulations, the design of discrete limiters and the evaluation of their capability to reduce the heat flux density on the FW, and finally a preliminary analysis of the heat loads effects on the Plasma Facing Components (PFC). All these aspects, together with preliminary limiter design, where considered since the beginning, in an integrated way.

Inter-machine plasma perturbation studies in EU-DEMO relevant scenarios: lessons learnt for EM forces prediction during VDEs

Abstract To support the deployment of DEMO wall protection strategy, the development of comprehensive analyses is essential to understand the implications of transient perturbations on the plasma shape control and on the vertical stability, some of the most critical aspects to be considered in elongated plasmas. Therefore, the design activities of the DEMO limiter structures need the deep understanding of the effects induced by transient plasma perturbations coupled with one of the most severe load conditions occurring in tokamaks, the Vertical Displacement Event (VDE). Since Electromagnetic (EM) loads during VDE phases are among the DEMO limiters design drivers, this study focuses on predictive simulations of the final plasma position and of EM loads following a VDE. For this purpose, a multi-tokamaks study supported by the construction of an inter-machine database containing experimental transient plasma perturbations and VDEs from JET and ASDEX Upgrade (AUG) has been carried out. It aims at the characterization of some transient plasma perturbations that may lead to high control efforts by the vertical stability system in terms of variations of the plasma internal parameters and vertical displacements. Consequently, such experimental transient plasma perturbations have been properly scaled to DEMO reference geometries with different magnetic configurations, to be simulated in terms of plasma dynamical behaviour by means of MAXFEA code. Finally, initial predictive EM loads on DEMO limiter structures will be discussed in the case of VDEs following plasma perturbations.