Seismic performance of innovative double layer space shear wall

Various kinds of seismic structural systems could not completely satisfy engineers due to excessive rigidity and low ductility. Then engineers innovate advanced ductile structural systems like viscous elastic dampers to dissipate earthquake forces and insulate important structural elements in safe zone; however these systems have not been pervasive in construction industry due to high production cost. Indeed, optimization of stiffness, ductility, and construction cost are the major challenges facing the engineering profession in designing a perfect lateral system. This research introduces Space Shear Wall (SpaSW), as an innovative earthquake resistant system for structures and evaluates its feasibility and seismic performance through three-dimensional linear and nonlinear-static, lineardynamic, and finite element analysis carried out by ETABS and ANSYS program. Space shear wall is defined as a double-layer diagonal space frame structure with ball joints vertically used as infill wall. The comparative study between SpaSW and steel bracing used in typical low to high-rise structures expressed that structural drift of SpaSW is slightly higher than steel bracing. However the ductility, energy dissipation, members’ stress and distribution of earthquake force in SpaSW are significantly better than typical steel bracing. In addition, failure mechanism of SpaSW were favourable due to its gradual process through many ball joints. Moreover, lightness, industrialization, maintainability and reparability, compatibility with architectural considerations, low cost, simple and fast fabrication are other realized advantages. Developing this concept would be considered in the future studies through optimization of material, grid patterns, connection, and additional dampers

Silk: A Potential Medium for Tissue Engineering

Objective: Human skin is a complex bilayered organ that serves as a protective barrier against the environment. The loss of integrity of skin by traumatic experiences such as burns and ulcers may result in considerable disability or ultimately death. Therefore, in skin injuries, adequate dermal substitutes are among primary care targets, aimed at replacing the structural and functional properties of native skin. To date, there are very few single application tissue-engineered dermal constructs fulfilling this criterion. Silk produced by the domestic silkworm, Bombyx mori, has a long history of use in medicine. It has recently been increasingly investigated as a promising biomaterial for dermal constructs. Silk contains 2 fibrous proteins, sericin and fibroin. Each one exhibits unique mechanical and biological properties. Methods: Comprehensive review of randomized-controlled trials investigating current dermal constructs and the structures and properties of silk-based constructs on wound healing. Results: This review revealed that silk-fibroin is regarded as the most promising biomaterial, providing options for the construction of tissue-engineered skin. Conclusion: The research available indicates that silk fibroin is a suitable biomaterial scaffold for the provision of adequate dermal constructs

Envirobot: A Bio-Inspired Environmental Monitoring Platform

Autonomous marine vehicles are becoming essential tools in aquatic environmental monitoring systems, and can be used for instance for data acquisition, remote sensing, and mapping of the spatial extent of pollutant spills. In this work, we present an unconventional bio-inspired autonomous robot aimed for execution of such tasks. The Envirobot platform is based on our existing segmented anguilliform swimming robots, but with important adaptations in terms of energy use and efficiency, control, navigation, and communication possibilities. To this end, Envirobot has been designed to have more endurance, flexible computational power, long range communication link, and versatile flexible environmental sensor integration. Its low level control is powered by an ARM processor in the head unit and micro processors in each active module. On top of this, integration of a computer-on-module enables versatile high level control methods. We present some preliminary results and experiments done with Envirobot to test the added navigation and control strategies

Environmental Monitoring using Autonomous Vehicles: A Survey of Recent Searching Techniques

Autonomous vehicles are becoming an essential tool in a wide range of environmental applications that include ambient data acquisition, remote sensing, and mapping of the spatial extent of pollutant spills. Among these applications, pollution source localization has drawn increasing interest due to its scientific and commercial interest and the emergence of a new breed of robotic vehicles capable of performing demanding tasks in harsh environments without human supervision. In this task, the aim is to find the location of a region that is the source of a given substance of interest (e.g. a chemical pollutant at sea or a gas leakage in air) using a group of cooperative autonomous vehicles. Motivated by fast paced advances in this challenging area, this paper surveys recent advances in searching techniques that are at the core of environmental monitoring strategies using autonomous vehicles

Propulsion module for generating wave-like motion

The present invention relates to a propulsion module (1) for generating wave-like motion in liquid. The propulsion module (1) comprises: a motor (7) for generating rotational motion; a set of conversion devices comprising a first conversion device (91) and a second conversion device (92) each comprising a movable arm (27) for converting the rotational motion from the motor (7) into oscillatory translational motion of the respective arm (27) along a movement axis, which is angled with respect to a length axis of the propulsion module; a drive mechanism for coupling the motor (7) to the first and second conversion devices (91, 92) for transferring the rotational motion to the first and second conversion devices; and a flexible structure (19) extending along at least a portion of the length axis of the propulsion module (1), the flexible structure (19) being configured to be guided by the movable arms (27) to generate the wave-like motion of the flexible structure (19). A distance between the first and second conversion devices along the length axis, and/or a maximum range of motion of the movable arms (27) along the movement axis is/are adjustable

Development of IgY-Based Sandwich ELISA as a Robust Tool for Rapid Detection and Discrimination of Toxigenic Vibrio cholerae

Background. The conventional methods for diagnosis of Vibrio cholerae are time consuming, complicated, and expensive. Development of rapid detection tests is critical for prevention and management of cholera. This study aimed to introduce two sensitive sandwich ELISAs based on avian antibodies (IgY) targeting outer membrane protein W (OmpW) and cytotoxin B (CtxB) antigens of V. cholerae. Methods. The sequences of ompW and ctxB genes were cloned into pET28a vector. Escherichia coli BL21 (DE3) was transformed with the recombinant vectors, and gene expression was induced by IPTG. The expressed proteins were purified by affinity chromatography using Ni-NTA resins. Two groups of white Leghorn chickens were immunized by recombinant proteins, and the generated antibodies were purified from egg yolks of chickens by PEG precipitation. The antibodies were used for the development of α-OmpW and α-CtxB ELISAs. Results. The expression and purification yielded 59 and 38 mg of recombinant OmpW and CtxB, respectively, per one liter of bacterial culture. PEG precipitation and purification of egg yolk antibodies yielded on average (±SD) 66.5 ± 1.80 and 50.9 ± 2.23 mg of purified α-OmpW and α-CtxB per egg, respectively. The analytical sensitivity of α-OmpW ELISA was 103 cfu/mL of V. cholerae and that of α-CtxB ELISA was 33 pg/mL of recombinant cytotoxin B. The two developed ELISAs did not show any cross-reactivity to any tested bacteria grown in common conditions. Discussion. The current study is the first report on using IgY for detection of V. cholerae. The developed ELISAs were shown to have considerable analytical sensitivity and specificity. Therefore, the assays can be one of the convenient methods for sensitive and specific detection of toxigenic V. cholerae strains in clinical and environmental samples

Optimal Search Strategies for Pollutant Source Localization

This paper is aimed at developing optimal motion planning for a single autonomous surface vehicle (ASV) equipped with an on-board pollutant sensor that will maximize the sensor-related information available for source seeking. The ASV uses a nonlinear diffusion model of the pollutant source to estimate the intensity/level of the pollution at the present ASV location. The rate of detection of particles depends on the relative distance between the ASV and the source. First, we use a probabilistic map of the source location built through the sensor information for a dynamic motion planning of source seeking based on an entropy reduction formulation, where an appropriately defined Fisher information matrix (FIM) is used for entropy reduction or information gain. We derive the FIM for the set-up and investigate optimal trajectories. Next, we present an online nonlinear Monte Carlo algorithm that uses the obtained sensor information about pollutant at different vehicle locations to update a probabilistic uncertainty map of pollutant source location. As the mission unfolds the ASV motion is computed by considering a moving-horizon interval of decision, which will allow for the inclusion of new information available for optimal motion planning. The proposed motion planning approach is extended to take into account external disturbances and it is able to minimize the uncertainty in the pollutant source. Finally, we provide two case studies to demonstrate efficacy of the proposed motion planning algorithm