Hasil untuk "Structural engineering (General)"

Rémi Veneziano, Sakul Ratanalert, Kaiming Zhang et al.

Shun Mao, H. Pu, Junhong Chen

E. Peraza-Hernandez, D. Hartl, Richard J Malak Jr et al.

J. Beltrán, Paul J. Steiner, Matthew A. Bedewitz et al.

A general method to generate biosensors for user-defined molecules could provide detection tools for a wide range of biological applications. Here, we describe an approach for the rapid engineering of biosensors using PYR1 (Pyrabactin Resistance 1), a plant abscisic acid (ABA) receptor with a malleable ligand-binding pocket and a requirement for ligand-induced heterodimerization, which facilitates the construction of sense–response functions. We applied this platform to evolve 21 sensors with nanomolar to micromolar sensitivities for a range of small molecules, including structurally diverse natural and synthetic cannabinoids and several organophosphates. X-ray crystallography analysis revealed the mechanistic basis for new ligand recognition by an evolved cannabinoid receptor. We demonstrate that PYR1-derived receptors are readily ported to various ligand-responsive outputs, including enzyme-linked immunosorbent assay (ELISA)-like assays, luminescence by protein-fragment complementation and transcriptional circuits, all with picomolar to nanomolar sensitivity. PYR1 provides a scaffold for rapidly evolving new biosensors for diverse sense–response applications.

Kwang-Rim Baek, Sudha Rani Ramakrishnan, Soo-Jung Kim et al.

Mannan and outer structural yeast cell wall polysaccharides have recently garnered attention for their health defense and cosmetic applications. In addition, many studies have confirmed that yeast cell wall mannans exhibit various biological activities, such as antioxidant, immune regulation, reducing hyperlipidemia, and gut health promotion. This paper elucidates yeast cell wall mannan structural features, biological activities, underlying molecular mechanisms, and biosynthesis. Moreover, mannan-overproducing strategies through yeast strain engineering are emphasized and discussed. This review will provide a scientific basis for yeast cell wall mannan research and industrial applications.

Mohamed Marzouk, Eman Othman, Mahmoud Metawie

Egypt has experienced vast urbanization and expansion in existing highways, leading to much demolition waste. Construction and demolition waste constitutes around half of the total municipal waste. So, these wastes must be appropriately managed to decrease their negative impacts. As a result, this research presents a framework that automatically detects demolishing wastes' location and optimizes utilized resources in demolition and transportation processes. It consists of three main components: the GIS module, the optimization module, and the decision-making module. Based on the raster image of the study region, the framework detects existing buildings that should be demolished to enable highways’ expansion. The GIS module is designated to quantify the volume of demolition waste in the studied area using ArcGIS Pro software. The optimization module determines the near-optimum combination of resources involved in the demolition process and waste transportation. These resources include labor crews, excavators, and trucks. The module performs multi-objective optimization using a non-dominated sorting genetic algorithm (NSGA-II). The optimization module considers three objectives in demolition and transportation processes: time, cost, and energy consumption. Finally, the decision-making module is developed to rank the Pareto front solutions. The Entropy Weight Method (EWM) is used to identify the weights of the three criteria. The estimated weights for time, cost, and energy consumption are 38.6%, 17.3%, and 44.1%, respectively. Subsequently, the TOPSIS technique is utilized to normalize, rank, and select the best solution. The proposed framework is applied to an actual case study that involves expanding the ring road project in Cairo to demonstrate its main features.

Yong Jiao

In the process of modernization with Chinese characteristics, the dam sector of China will embrace a new development climax. A new layout of the national water network will be formed by the combination of major natural river systems and water infrastructures including water division channels, dams and reservoirs, hydropower stations, river dikes, flood retention areas, etc. The massive investment demand released in the construction of many planned/ongoing projects will drive the reform of the supply side. Many new requirements for modern dam construction and operation will be imposed following the national’s goal of high-quality development, and new challenges will arise from aquatic ecosystem protection and restoration. These strategic needs form the basis for new research and development (R&D) missions of China’s hydraulic-hydropower industry.

Jiateng Guo, Xulei Wang, Jiangmei Wang et al.

Abstract Three-dimensional (3D) geological modeling based on borehole data usually requires many manual operations, and the modeling process remains very complicated and time consuming. This paper presents an automatic implicit 3D geological modeling and visualization method that can be applied to urban geotechnical drilling data. First, by analyzing the general characteristics of these types of data, the implicit Hermite radial basis function (HRBF) surface is used to simulate geological interfaces according to lithological layers/units in boreholes. Second, the marching tetrahedra (MT) visualization method is optimized with new data structures and split operations to extract explicit mesh models from implicit geological surfaces. Then, the optimized tetrahedron used in the field of 3D urban drilling modeling is described in detail. Finally, the local geotechnical engineering data of two Chinese cities are used to verify the modeling algorithm, and several kinds of spatial analyses are carried out, including visualization, data querying, accuracy assessment and multiple cutting methods. The results show that the proposed urban subsurface 3D geological modeling method is effective in visualizing the structural shape, topological relationship and formation properties of strata that can be used to predict underground conditions and reduce construction risks during urban geotechnical engineering projects.

Xiaopeng Han, Xiaopeng Li, Jai White et al.

As an emerging battery technology, metal–air flow batteries inherit the advantageous features of the unique structural design of conventional redox flow batteries and the high energy density of metal–air batteries, thus showing great potential as efficient electrochemical systems for large‐scale electrical energy storage. This review summarizes the operating principles and recent progress of metal–air flow batteries from a materials and chemistry perspective, with particular emphasis on the latest advanced materials design and cell configuration engineering, which the authors divide into three categories based on the anode species: vanadium–air, zinc–air, and lithium–air flow batteries. Since some of the capabilities developed for metal–air static batteries can be leveraged for next‐generation flow systems, classical works on conventional metal–air batteries are selected and compared with the metal–air flow systems, highlighting the prominent advantages of the latter in achieving high energy capacity and long cycle performance. At the end, a general perspective on current challenges/opportunities and future research directions to promote the commercial application of the metal–air flow battery technology is provided. The aim is to provide a comprehensive overview and to set up a road map for guiding development from conventional static to advanced flow technologies of metal–air batteries.

Lin Chen, Jie Deng, Ailing Yu et al.

Boosting transcorneal permeability and pharmacological activity of drug poses a great challenge in the field of ocular drug delivery. In the present study, we propose a drug-peptide supramolecular hydrogel based on anti-inflammatory drug, dexamethasone (Dex), and Arg-Gly-Asp (RGD) motif for boosting transcorneal permeability and pharmacological activity via the ligand-receptor interaction. The drug-peptide (Dex-SA-RGD/RGE) supramolecular hydrogel comprised of uniform nanotube architecture formed spontaneously in phosphate buffered saline (PBS, pH = 7.4) without external stimuli. Upon storage at 4 °C, 25 °C, and 37 °C for 70 days, Dex-SA-RGD in hydrogel did not undergo significant hydrolysis, suggesting great long-term stability. In comparison to Dex-SA-RGE, Dex-SA-RGD exhibited a more potent in vitro anti-inflammatory efficacy in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages via the inhibition of nuclear factor кB (NF-κB) signal pathway. More importantly, using drug-peptide supramolecular hydrogel labeled with 7-nitro-2,1,3-benzoxadiazole (NBD), the Dex-SA-K(NBD)RGD showed increased performance in terms of integrin targeting and cellular uptake compared to Dex-SA-K(NBD)RGE, as revealed by cellular uptake assay. On topical instillation in rabbit's eye, the proposed Dex-SA-K(NBD)RGD could effectively enhance the transcorneal distribution and permeability with respect to the Dex-SA-K(NBD)RGE. Overall, our findings demonstrate the performance of the ligand-receptor interaction for boosting transcorneal permeability and pharmacological activity of drug.

Zhongjian Miao, Jingru Li, Sheng Li et al.

In this study, a new type of 2D piezoelectric phononic crystal with a square hollow and convex structures is designed and established. A theoretical study of the piezoelectric phononic crystal is presented in this article to investigate the transmission properties of waves in terms of complex dispersion relations. Based on the finite discretization technique and plane wave expansion, the formula derivation of the real band structure is achieved as well as the complex band diagrams are obtained. The numerical results are presented to demonstrate the multiple broadband complete bandgaps produced by the designed piezoelectric phononic crystal and the propagation characteristics of the elastic waves for different directions. In addition, the transmission loss in the ΓX direction is calculated to verify the band structure. Finally, the effects of the thickness and the square hollow side length on the band structure are discussed.

Lei Zhang, Zhaoxiong Xie, Jinlong Gong

Hocine Hammoum, Amar Aliche, Karima Bouzelha et al.

The design of concrete elevated water tanks involves several kinds of uncertainties. Traditionally, the design of these structures is based on a deterministic analysis. Partial safety factors prescribed in design codes are applied to take into account these uncertainties and to ensure sufficiently safe design. However, this approach does not allow rational evaluation of the risk related to the structural failure and consequently its reliability. In fact, the partial safety factors can lead to over-designed structures; or to under designed structural components leading to a lack of structural robustness. In this study, a probabilistic approach based on Monte Carlo simulations is used to analyze the reliability of elevated water tanks submitted to hazard seismic loading. This reliability approach, takes into account mainly two parameters. Firstly, the hydraulic charge in the tank container which is a function of time, and secondly, the hazard seismic loading through the Peak Ground Acceleration is considered as a random variable. Fragility curves depending on seismic zones and soil types are obtained by using the probabilistic approach, where they demonstrate the dominant failure modes that can cause the structural failure with respect to different seismic levels, soil types and water height level in the tank container.

Sercan Saray, Tanzer Satır, Neslihan Dogan-Saglamtimur

Effective communication in the sea and ocean can only be achieved through a common language. Maritime professions in Turkey for many years have been seen as an important area of employment. Maritime vocational and technical high schools are also seen as educational institutions that play an important role in this field. In this study, it has been aimed to define the level of general and Maritime English education provided by the maritime vocational high schools, the problems and deficiencies of education, and what must be done to improve the education quality. A questionnaire was conducted to 200 graduates of maritime vocational high schools in order to determine the efficiency, deficiencies and issues that need to be improved. The results of the survey were analyzed by SPSS and made meaningful.  For analysis, t-test was used to evaluate numerical data between two independent groups and One-Way Analysis of Variance (ANOVA) test was used to evaluate numerical data between more than two independent groups. After the One-Way ANOVA Test, Tukey Test was used as a complementary Post-Hoc analysis to determine the differences. Finally, Pearson correlation method was used to evaluate the continuous numerical variables used in the research. As a result of the research, it has been seen that Maritime English education in vocational high schools is far from meeting the needs of today's world and the maritime sector. It was observed that the graduates felt this inadequacy heavily on ships and experienced the effects of this deficiency in all of their professional life. As stated in the survey results, it is thought that the Maritime English educators with sea experience will increase the motivation of the students. Programs sourced from the field need to be reorganized. Also, it will be beneficial to rearrange the requirements of the seafarer educators for giving English lessons.

Himanshu Nagpal, Andrea Staino, Biswajit Basu

In this work, an algorithm for the scheduling of household appliances to reduce the energy cost and the peak-power consumption is proposed. The system architecture of a home energy management system (HEMS) is presented to operate the appliances. The dynamics of thermal and non-thermal appliances is represented into state-space model to formulate the scheduling task into a mixed-integer-linear-programming (MILP) optimization problem. Model predictive control (MPC) strategy is used to operate the appliances in real-time. The HEMS schedules the appliances in dynamic manner without any a priori knowledge of the load-consumption pattern. At the same time, the HEMS responds to the real-time electricity market and the external environmental conditions (solar radiation, ambient temperature, etc.). Simulation results exhibit the benefits of the proposed HEMS by showing the reduction of up to 70% in electricity cost and up to 57% in peak power consumption.

Iulian Popescu, Ludmila Sass, Alina Duta et al.

Different variants of cardioids were reviewed and authors decided to an end to focus on the usability of a Double-heart curve. Starting from the geometric information related to its generation, the synthesis of an original generating mechanism was performed firstly, followed by the realization of its structural analysis. Mechanism’s positions were computed and the imposed curve was generated. The variations of certain trajectories were deduced from the corresponding diagrams. The mechanism sizes were modified and a wide class of curves presenting interest from the geometric point of view was obtained. Some mathematical properties of the curves generated by the above mechanism are studied (binormal vector, tangent equation in a current point, normal plane equation, tangent versor, versor of normal to the curve).

Tabassum Mahzabeen RAKA, Khan Mahmud AMANAT

The study focuses on the finite element (FE) modelling of cold formed plain lipped C-section in shear, and combined bending and shear, which was developed using ANSYS. Hence, a parametric study on plain C-section was conducted to investigate the applicability of the direct strength method (DSM). In addition, DSM capacity curves were constructed to find out the limitations of DSM. It is found that the DSM equations for nominal shear capacity with tension field action (TFA) gives the capacity that is acceptable when full tension field action is developed while the nominal DSM moment capacity at local buckling outlines conservative results. However, the study also reveals that the DSM nominal shear capacity without tension field action provides lower capacity than the real peak capacity and therefore, it concludes that this method is more conservative.