ABSTRACT
Additive manufacturing (AM) enables the spatially configurable 3D integration of sensors in metal components to realize smart materials and structures. Outstanding sensing capabilities and size compatibility have made fiber optic sensors excellent candidates for integration in AM components. In this study, fiber Bragg grating (FBG) sensors were embedded in Inconel 718 tensile coupons printed using laser powder bed fusion AM. On-axis (fiber runs through the coupon's center of axis) and off-axis (fiber is at 5° and 10° to the coupon's center of axis) sensors were buried in epoxy resin inside narrow channels that run through the coupons. FBGs' spectral evolutions during embedment in the coupons were examined and cyclic loading experiments were conducted to analyze and evaluate the sensor integration process, complex strain loading, process flaws, and sensing performance. This study also demonstrates that the AM process-born deficiencies such as poor surface finish and staircase effects can be detrimental to the embedded sensors and their sensing performance.
ABSTRACT
The significant increase in energy consumption has facilitated a rapid increase in offensive greenhouse gas (GHG) and CO2 emissions. The consequences of such emissions are one of the most pivotal concerns of environmental scientists. To protect the environment, they are conducting the necessary research to protect the environment from the greenhouse effect. Among the different sources of CO2 emission, power plants contribute the largest amount of CO2 and as the number of power plants around the world is rising gradually due to increasing energy demand, the amount of CO2 emission is also rising subsequently. Researchers have developed different potential technologies to capture post-combustion CO2 capture from powerplants among which membrane-based, cryogenic, absorption and adsorption-based CO2 processes have gained much attention due to their applicability at the industrial level. In this work, adsorption-based CO2 technologies are comprehensively reviewed and discussed to understand the recent advancements in different adsorption technologies and several adsorbent materials. Researchers and scientists have developed and advanced different adsorption technologies including vacuum swing adsorption, temperature swing adsorption, pressure swing adsorption, and electric swing adsorption, etc. To further improve the CO2 adsorption capacity with a compact CO2 adsorption unit, researchers have integrated different adsorption technologies to investigate their performance, such as temperature vacuum swing adsorption, pressure vacuum swing adsorption, electric temperature pressure swing adsorption, etc. Different adsorbent materials have been tested to evaluate their applicability for CO2 adsorption and among these adsorbents, advanced carbonaceous, non-carbonaceous, polymeric, and nanomaterials have achieved much attention due to their suitable characteristics that are required for adsorbing CO2. Researchers have reported that higher CO2 adsorption capacity can be achieved by integrating different adsorption technologies and employing suitable adsorbent material for that system. This comprehensive review also provides future directions that may assist researchers in developing novel adsorbent materials and gaining a proper understanding of the selection criteria for effective CO2 adsorption processes with suitable adsorbents.
