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PVP-Assisted Hydrothermal Synthesis of Bi2O2Se Nanosheets for Self-Powered Photodetector
Full text linkAbstract: Bi2O2Se nanosheets were successfully synthesized via a facile one-step PVP-assisted hydrothermal process for the first time. Corresponding characterizations, such as XRD, XPS, SEM and TEM, were carried out to investigate the formation of the products on the amount of PVP in the reaction system. Results revealed that the single-crystalline Bi2O2Se nanosheets with small mean lateral size of 176.3 nm were obtained when the amount of PVP is 0.75 g. Single-crystalline Bi2O2Se nanosheets self-powered photodetector exhibited excellent photodetection performance, superior to that of self-powered photodetectors based on the products synthesized without PVP and other nanomaterials. Under the illumination of 365 nm ultraviolet light, the rise time, responsivity and detectivity could approach up to 9 ms, 14.24 mA/W and 3.16×108 Jones, respectively. Bi2O2Se devices have high photoresponse even in the visible and near infrared bands due to its suitable band gap. The present work provides a novel preparation route of Bi2O2Se via hydrothermal method and PVP assisted synthesis of Bi2O2Se nanosheets is reported for the first time. Bi2O2Se nanosheets self-powered photodetector exhibited excellent photodetection performance and points out a direction for the evolution of self-powered photodetectors in the in the future
Part 2 Composition Materials With Metal Matrix Condensed from the Vapor Phase
Full text linkIn this article, the present-day problems of microporous condensed materials obtained from the vapor phase are discussed. The pore sizes are regulated by the amount of the second phase concentration and the deposition temperature.
The oxides, fluorides, and sulfides can be used as the second phase and non-removable inclusions. The open porosity can be regulated from 0% to 50 %of the porosity and with average porose sizes of 0.1 to 8 µm. The condensed micro-porous materials can be deposited in coating form or the form of massive bulk sheet materials with a thickness of up to 6 mm and a diameter of 1m
Advances in 3D Printing for Electrochemical Energy Storage Systems
Full text linkIn the current scenario, energy generation is relied on the portable gadgets with more efficiency paving a way for new versatile and smart techniques for device fabrication. 3D printing is one of the most adaptable fabrication techniques based on designed architecture. The fabrication of 3D printed energy storage devices minimizes the manual labor enhancing the perfection of fabrication and reducing the risk of hazards. The perfection in fabrication technique enhances the performance of the device. The idea has been built upon by industry as well as academic research to print a variety of battery components such as cathode, anode, separator, etc. The main attraction of 3D printing is its cost-efficiency. There are tremendous savings in not having to manufacture battery cells separately and then assemble them into modules. This review highlights recent and important advances made in 3D printing of energy storage devices. The present review explains the common 3D printing techniques that have been used for the printing of electrode materials, separators, battery casings, etc. Also highlights the challenges present in the technique during the energy storage device fabrication in order to overcome the same to develop the process of 3D printing of the batteries to have comparable performance to, or even better performance than, conventional batteries
Investigation of Hybrid Composite Properties Fabricated from Bagasse Fibers Reinforced with Al2O3 and SiC for Light Weight Applications
Full text linkThe primary purpose of this study was to investigate mechanical properties of hybrid composite fabricated from bagasse fibers reinforced with Al2O3 and SiC for automotive purposes. The technique applied was referred to as the hand layup technique for the fabrication of composite. The experiment was conducted based on Taguchi L9 orthogonal array design. Data shows that the maximum tensile and flexural strength were 39.9 and 56.1 MPa respectively. Hardness and impact strength were 75.05 HV and 14 J respectively. The results indicated that the increasing Al2O3 and SiC wt.% increase the tensile strength and after bagasse fiber wt.% reaches optimum values the tensile strength decreased. Increasing Al2O3 wt.%, increases flexural strength and after bagasse fiber and SiC wt.% reaches optimum values, flexural strength was decreased. Increasing bagasse fiber wt.% increases the hardness of composite, and increasing Al2O3 and SiC wt.% increases the hardness, then after reaching optimum values the hardness was decreased. Increasing Al2O3 wt.% after the optimum values decrease the impact strength, and increasing bagasse fiber and SiC wt.% increase impact strength. The developed hybrid composite material was found to be improved the properties of composites after addition of Al2O3 and SiC powder as filler materials. This thesis recommends higher institutes, automotive companies, manufacturing companies, the construction sector and the government to conduct on how to utilize this abundant waste of bagasse fiber resource
Analytical Method for Screw Rotor Cutting according to the Cutter Workpiece Engagement Model
Full text linkAbstract: The proper screw rotor cutting process is essential to obtain a precise rotor profile; however, it is a costly and high hazard if studied in a practical method. This study introduces an analytical screw cutting method to ensure the cutting process is running well and acquire the expected rotor profile. Two distinct cutter types, a cutter with a single curve and multiple inserts cutting edge, were applied. The analytical screw cutting method was developed according to the cutter-workpiece engagement model. The result reveals that the analytical screw cutting model using various cutters can generate identical simulated profiles and close to the original rotor profile. In addition, the virtual machining verification using VERICUT software was conducted to evaluate the proposed method. Conclusively, the analytical screw cutting method is reliable and realistic to be applied in screw rotor milling
A Decoupled Motion Estimation for Visual Regulation of Nonholonomic Mobile Robot
Full text linkA visual regulation strategy based on a decoupled ego-motion estimation technique, is presented for a nonholonomic mobile robot. Ego-motion in a static environment can be robustly estimated by planar region alignment, which initially detects the 2D planar motion between two frames, and the 2D motion is used to align corresponding image regions. Such a 2D registration removes all effects of the camera rotation, and the resulting residual displacement between the two aligned images is an epipolar field centered at the FOE (Focus of Expansion). Then 3D camera translation is recovered from the epipolar field. The 3D camera rotation is then derived from the recovered 3D translation and the detected 2D motion. By this way, the ego-motion estimation is decoupled into a 2D parametric motion and residual epipolar parallax displacements, which avoids many of the inherent ambiguities and instabilities associated with decomposing the image motion into its rotational and translational components, and hence makes the computation of ego-motion or 3D structure estimation more robust. Based on the ego-motion estimation, an adaptive control law for visual regulation of nonholonomic mobile robot is presented and the stability of the close loop system is analyzed in the sense of Lyapunov stability theory. Experiments show that the convergence of the proposed visual regulation
Theoretical Analysis and Experimental Study of Time-Varying Electric Field and Electrostatic Adhesion Force Generated by Interdigital Electrode Arrays
Full text linkA theoretical model is presented for the analysis of the electric field and electrostatic adhesion force produced by interdigital electrode arrays. The electric field is derived by solving the Laplace equation for the electrical potential in each subregion. The electrostatic adhesion force is calculated using the Maxwell stress tensor formulation. The dynamic properties of the electric field and electrostatic adhesion force are assessed by evaluating the transient response of the field and force under a step in applied voltages. Experimental studies are carried out to evaluate the adhesion performance of an electrode panel on a glass pane, and the experimental results verify the correctness of the theoretical model
Intelligent Power Grasp Through Layered Magnetization by A Serial Arm Field Robot Pages
Full text linkField applications of serial-arm static robotic system for material handling operations pose serious technological challenges under unstructured environments, in contrast to the same in situations with known perspectives of the obstacles therein. The present paper describes the design, analysis and development of a novel magnetic gripper, along with its sensorized peripherals, deployed in a non-coherent unstructured workspace. The prototype gripper was augmented with a four degrees-of-freedom SCARA type industrial robot and the field-unit was programmed to perform the intended operation of handling steel bearing races of various categories round-the-clock. The robotic cell was equipped with multiple sensors, hardware interfaces and safety measures (e.g. electronic light barrier), designed indigenously. The paper also analyses the performance of the magnetic gripper in the field through mathematical model, pertaining to this maiden application of robotics in Indian steel industries
Automated Agricultural Robot and Sensor Data Collection and Analysis through a Biomass Feedstock Production Information System
Full text linkThe increasing environmental pollution resulting from the use of non-renewable fossil fuels as well as the development of economic dependencies among countries because of the lack of such types of fuels underline the intense need for the use of sustainable forms of energy. Biomass derived biofuels provide such an alternative. The main tasks of biomass feedstock production are planting and cultivation, harvest, storage, and transportation. A number of complex decisions characterize each of these tasks. These decisions are related to the monitoring of crop health, the improvement of crop productivity using innovative technologies, and the examination of limitations in existing processes and technologies associated with biomass feedstock production. Other critical issues are the development of sustainable methods for the delivery of the biomass while maintaining product quality. There is the need for the development of an automated integrated research tool based on resilience and sustainability which will allow the coordination of different research fields but also perform research on its own. The specific tool should aim in the optimization of different parameters which specify the research done and in the case of biomass feedstock production; such parameters are the transportation of biomass from the field to the biorefinery, the equipment used, and the biomass storage conditions. This optimization would enhance decision making in the field of bioenergy production. Based on the need for such an automated integrated research tool, this paper presents an information system that provides automated functionalities for better decision making in the bioenergy production field based on the collection and analysis of agricultural robot and sensor data
Properties of ((CH3NH3)1-xCsx)3Bi2I9: (x=0-1.0) Hybrid Perovskite Solar Cells with Chlorobenzene Treatment
Full text linkAbstract: Hybrid-perovskite solar cells, a promising lead-free perovskite material, have been attracted for optoelectronic applications due to an excellent optical and electrical properties with low production cost. Herein, methylammonium bismuth iodide and cesium bismuth iodide were mixed to form hybrid structure for the improvement of photovoltaic properties, which were fabricated using all-solution processed multi-step spin coating technique with changing the composition, x, of CBI, ((CH3NH3)1-xCsx)3Bi2I9; (x=0 – 1.0). Chlorobenzene was added to the solution to improve the surface morphology. By optimizing the composition of CBI in MBI, the morphology, structural and optical properties of HPeSCs have been improved. It showed that the morphology is homogeneous, compact and a uniform layer, while the crystallinity shows an improvement as well. The open circuit voltage, the short circuit current and the power conversion efficiency were much improved with using hybrid structure. Our study shows that the significance of the hybridization process gives a new route in fabricating a better active absorber layer of PeSCs in the future