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Direct ink write deposition facilitates line‐by‐line extrusion of inks spanning wide viscoelastic ranges. Following deposition, post processing technologies permit tuning of the extrudate's material property characteristics—ultraviolet (UV) irradiation, facilitating the photopolymerization of UV‐reactive catalyst solutions, permits targeted modification of the extrudate's microstructure and in situ tuning of extrudate macrostructure. This report analyzes the morphological, rheological, and microstructural property relationships governing the printability, and processivity, of extruded UV‐curable resin inks for delineation of sufficiency and optimization of ink printability utilizing direct ink write technologies. A design‐of‐experiments approach is implemented to quantify significance regarding an extrudate's dimensional response to extrusion parameter variation and in situ processing parameters, identifying proportionally of nozzle velocity, nozzle height, and UV irradiation exposure with extrudate aspect ratio, reflected by respective maximum extrudate aspect ratio increases of 158% and 109%, regarding 121 and 123K resin inks. Finally, the relationship between extrudate morphology and microstructure variation was assessed via dielectric cure monitoring, whereby an extrudate's ion viscosity was calculated in relation to its rheological modulus, reflecting the relationship between an extrudate's morphology, rheological response, and printability, regarding its microstructural variation. [ABSTRACT FROM AUTHOR]

This paper describes a new system – Vehicle Kit (VEKIT), which uses a secure web-based interface for the authentication and monitoring of Vehicular Ad-Hoc Network (VANET) infrastructure and for preventing environment pollution. This paper presents the hazards caused by the usage of bags made of plastic material and proposes the design of VEKIT, which is to be installed in the vehicles for reducing the usage of such carry bags up to 75%. The survey results prove that the proposed VEKIT approach is very much relevant to solve the pollution problem faced by various countries. This novel application adds value to the future VANET projects by helping the countries to prevent pollution. The web interface of VEKIT presented in the paper can also be used to monitor the vehicles for their authenticity. A secure architecture is proposed for the usage of VANET in transport related projects. First published online 1 September 2020

Ground source heat pumps (GSHP) are a very efficient system for space heating and cooling, and it was established in 1904. GSHPs can minimize the environmental effect of buildings by using the ground as a renewable energy source. The ground will act as a heat sink or heat source. The research collection aims at finding the various possible opportunities for the effective integration of shallow geothermal energy (SGE) to decrease the fossil energy in the built environment and to reduce emission associated with it. The direct utilization of SGE using a ground source heat pump (GSHP) has been reviewed in detail for global north and global south countries, with a primary focus on heating application. The punctual information of results of various authors have been extensively summarized. This review discusses the GSHP installation status, SGE availability, GSHP system simulation, feasibilities, and performance. Worldwide more than one million GSHP systems have been installed, and the system is prevalent in Europe, the Americas, and Asia. Most of the systems are installed for heating-dominated buildings in the global north. This paper also contains the research details pertaining to the last two decades about refrigerants and compressors for the development of GSHP. Finally, the feasibility study and the performance of the GSHP unit for different climatic conditions are reviewed and it is found that the technique is more feasible for cold and dry climatic conditions. This paper highlights the recent research findings and a potential gap in the above components for further research and development. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) has emerged as a transformative technology capable of fabricating complex geometries and multi-material structures across various industries. Despite its potential, challenges persist in terms of limited material selection, anisotropic properties, and achieving functional microstructures in polymer and metal composites. Field-assisted additive manufacturing (FAAM) employs external fields like acoustic, magnetic, and electric fields. It has shown promise in addressing these limitations by controlling filler orientation and concentration in polymeric composites and improving surface finish and microstructure in metals. This review paper provides a comprehensive analysis of the state-of-the-art FAAM processes for polymer and metal composites, focusing on material compatibility, the mechanics of each field, and their integration with AM technologies as well as current applications, limitations, and potential future directions in the development of FAAM processes. Enhancing FAAM process understanding can create tailored anisotropic composites, enabling innovative applications in aerospace, automotive, biomedical fields, and beyond. [ABSTRACT FROM AUTHOR]

This research introduces a readily available and non-chemical combinatorial production approach, known as the laser-induced writing process, to achieve laser-processed conductive graphene traces. The laser-induced graphene (LIG) structure and properties can be improved by adjusting the laser conditions and printing parameters. This method demonstrates the ability of laser-induced graphene (LIG) to overcome the electrothermal issues encountered in electronic devices. To additively process the PEI structures and the laser-induced surface, a high-precision laser nScrypt printer with different power, speed, and printing parameters was used. Raman spectroscopy and scanning electron microscopy analysis revealed similar results for laser-induced graphene morphology and structural chemistry. Significantly, the 3.2 W laser-induced graphene crystalline size (La; 159 nm) is higher than the higher power (4 W; 29 nm) formation due to the surface temperature and oxidation. Under four-point probe electrical property measurements, at a laser power of 3.8 W, the resistivity of the co-processed structure was three orders of magnitude larger. The LIG structure and property improvement are possible by varying the laser conditions and the printing parameters. The lowest gauge factor (GF) found was 17 at 0.5% strain, and the highest GF found was 141.36 at 5%. [ABSTRACT FROM AUTHOR]

Dynamic bond exchanging vitrimers have emerged recently due to their malleability, self‐heal ability, recyclability, and mechanical stability. Likewise, 3D printing is consciously introduced at different platforms for ease of fabrication, high throughput, cost‐effectiveness, and waste reduction. These two distinctive techniques have recently made their consensus performance, resulting from a phenomenal change in the printing field. Conventionally, thermoplastic inks have been primarily used in 3D printing, owing to their effortless processability. At the same time, thermosets were utilized for their superior mechanical strength. However, these two essential properties have been required to be presented in the printed material. In that scenario, thermoset vitrimer materials have been introduced in 3D printing, where malleability and mechanical stability have been observed in the same material. Thus, this article details the recent vitrimer material included with the different 3D printing system systems with their reported results to understand and make them widespread. Eventually, the outlook and perspectives could be helpful to understand and enhance this specific field. [ABSTRACT FROM AUTHOR]

The primary objective of the paper is to identify the effective way to enhance the conductive and convective heat transfer of the FPSC. The performance enhancements of different FPSC components such as absorber plate, absorber tube, and heat transfer fluid are reviewed in detail. The influence of absorber plate configurations, material properties, a center-to-center distance of the absorber tube, plate thickness, coatings, and tube geometry have been assessed to increase the conduction heat transfer. Also, the augmentations of convective heat transfer using different nanofluids in FPSC such as Al2O3/water, CuO/water, CNT/water, TiO2/water, SiO2/water, graphene oxide/water, MgO/water, CeO2/water, WO3/water, ZnO/water, and hybrid nanofluids are evaluated in detail. The performance improvements using both conductive and convective (combined) passive technique have been elaborated. The table representation has been used to describe the activities performed in each paper which include FPSC type, passive technique detail, properties of heat transfer fluid, Reynolds number, heat transfer aspects, pumping power, energy, exergy, environmental aspects, and inference. These data will help the researcher to identify existing activities and the potential gap. This review paper also deals with the suggestions for the research work which can be carried out in the direction of heat transfer from solar flat plate collectors. [ABSTRACT FROM AUTHOR]

A thermally activated building system (TABS) is the most promising technology for reducing heat gain, cooling demand, and improved indoor comfort inside the built environment. This study investigates the energy consumption and thermal environment performance of the cooling tower-based thermally activated building system (passive system) integrated with a chiller unit (active cooling system). Energy consumption and indoor environment parameters, such as heat flux, indoor air, wall, floor, and the operative temperature, were measured in two computer laboratories of the same size and orientation operated with a chiller unit and chiller-integrated passive system. This strategy involved pre-cooling the building thermal mass during unoccupied hours via TABS and continuously using the system while maintaining zone temperatures at the comfort region during the occupied period. The results show that chiller-integrated TABS has a maximum heat gain of 10 W/m2 and maintains a mean radiant temperature from 24°C to 26°C for 80% of the interval. Furthermore, due to the pre-cooling effects of TABS, chiller-integrated TABS has a peak monthly energy savings of 6% and a CO2 emission reduction of 8% compared to an active cooling system. [ABSTRACT FROM AUTHOR]

This paper examines the problem of attitude estimation for passively magnetically stabilized spacecraft using only sun-vector measurements. An analytical investigation of local observability is performed in the case where the spacecraft magnetic dipole is constant. This is relevant because for passively stabilized spacecraft using permanent magnets and magnetic hysteresis rods, the hysteresis rod dipole moments are nearly constant at steady state. It is shown that under reasonable assumptions on the Earth's magnetic field, not only are the attitude and angular velocity locally observable, but if one component of the magnetic dipole moment is known, then the remaining two components of the magnetic dipole moment are locally observable also. Numerical examples of three attitude estimation schemes are presented, demonstrating successful state estimation of passively magnetically stabilized spacecraft. [ABSTRACT FROM AUTHOR]

The article focuses on the formation of a hybrid linear/nonlinear controller that combines the efficacies of linear control and time-optimal bang-bang control methodologies to efficiently maneuver spacecraft in formation. It cites that the system equations are devised based on the time-averaged values of the relative coordinates rather than their immediate values. It states that the general performance of the formulated hybrid linear/nonlinear control law is demonstrated to be better in terms of control usage and transient time.

This paper investigates the feasibility of using differential drag as a means of nano-satellite formation control. Differential drag is caused when the ballistic coefficients of the spacecraft in a formation are not equal. The magnitude of differential drag depends on the difference in ballistic coefficients and also the altitude of the spacecraft formation. AGI's Satellite Tool Kit (STK) is used initially to assess the magnitude of drifts caused due to differential drag for different altitudes. This information is then used to show that it is feasible to use differential drag for spacecraft formation control. A simple PID controller is then implemented that adjusts the cross- sectional areas of the satellites such that the energies of the orbits remain equal. Results are presented that show that the control law can maintain the formation separation with reasonable accuracy. [ABSTRACT FROM PUBLISHER]