Fabrication of a Capacitive Relative Humidity Sensor Using Aluminum Thin Films Deposited on Etched Printed Circuit Board

A capacitive humidity-sensing device was created by thermal evaporation of 99.999% aluminum. The substrate used for the coating was etched double-sided printed circuit board. The etched printed circuit board serves as the dielectric of the capacitor while the aluminum thin films deposited on either side serve as the plates of the capacitor. The capacitance was measured before and after exposure to humidity. The device was then calibrated by comparing the readings of capacitance with that of the relative humidity sensor of the Vernier LabQuest2. It was found that there is a linear relationship between the capacitance and relative humidity given by the equation C=1.418RH+29.139 where C is the capacitance and RH is the relative humidity. The surface of the aluminum films is porous and it is through these pores that water is adsorbed and capillary condensation occurs, thereby causing the capacitance to change upon exposure to humidity

Comprehensive Study of Industry 4.0 in Robotics for Policy Development

Robotics has advanced greatly in the past years. Modern robots can do complex tasks and are the central components of Industry 4.0. These improvements make robots applicable in a variety of fields like security, exploration, entertainment, agriculture, healthcare and industry. While advancements in robotics come with many advantages, it still faces roadblocks that hinder its development or implementation. To aid in the public acceptance and adoption of robotics in the industry, policy development is critical to minimize the social and economic effects. Several policy recommendations were made such as improved government support, wage insurance, upskilling programs, information dissemination, and robot tax, which would accelerate robotics development, bolster job security, publicize key information, and stabilize taxation

Progress in biomass torrefaction: Principles, applications and challenges

The development of biofuels has been considered as an important countermeasure to abate anthropogenic CO2 emissions, suppress deteriorated atmospheric greenhouse effect, and mitigate global warming. To produce biofuels from biomass, thermochemical conversion processes are considered as the most efficient routes wherein torrefaction has the lowest global warming potential. Combustion is the easiest way to consume biomass, which can be burned alone or co-fired with coal to generate heat and power. However, solid biomass fuels are not commonly applied in the industry due to their characteristics of hygroscopic nature and high moisture content, low bulk density and calorific value, poor grindability, low compositional homogeneity, and lower resistance against biological degradation. In recently developing biomass conversion technologies, torrefaction has attracted much attention since it can effectively upgrade solid biomass and produce coal-like fuel. Torrefaction is categorized into dry and wet torrefaction; the former can further be split into non-oxidative and oxidative torrefaction. Despite numerous methods developed, non-oxidative torrefaction, normally termed torrefaction, has a higher potential for practical applications and commercialization when compared to other methods. To provide a comprehensive review of the progress in biomass torrefaction technologies, this study aims to perform an in-depth literature survey of torrefaction principles, processes, systems, and to identify a current trend in practical torrefaction development and environmental performance. Moreover, the encountered challenges and perspectives from torrefaction development are underlined. This state-of-the-art review is conducive to the production and applications of biochar for resource utilization and environmental sustainability. To date, several kinds of reactors have been developed, while there is still no obviously preferred one as they simultaneously have pros and cons. Integrating torrefaction with other processes such as co-firing, gasification, pyrolysis, and ironmaking, etc., makes it more efficient and economically feasible in contrast to using a single process. By virtue of capturing carbon dioxide during the growth stage of biomass, negative carbon emissions can even be achieved from torrefied biomass

Transforming food systems in Maritime Southeast Asia and Pacific Small Island Developing States to support food security and sustainable healthy diets

Food is one of the basic necessities for human life. Nutritious food is essential for human health and helps oneself live up to our best potential as productive members of society. In spite of this, 3 billion people are estimated to have limited access to nutrient-rich food, and there are 768 million undernourished people in the globe today. There are still concerns with food systems and food security, despite the fast economic transformation of low-and middle-income nations in Maritime Southeast Asia and Oceania over the past 10 years. These issues include dwindling agricultural land, deforestation, ineffective food supply networks, environmental degradation, changing and unhealthy diets, non-communicable diseases, disappearing cultural legacy, and ineffective policies. These problems are exacerbated by climate change, natural hazards, and pandemic shocks. This review explores the perspectives of food systems that relates to all the elements and activities in transforming agri-food industry. In this paper, we discuss the challenges and solutions to transforming food systems in this region to achieve a sustainable and healthy diet for all, with the perspective of bringing the region closer toward the UN sustainable development goals. This paper is an outcome of the deliberations that took place during the Food Security in Small Islands and Developing States workshop in 2020. It also includes insights from subsequent expert group sessions that focused on the following topics: Agriculture and Food Systems; Nutrition, Health, and Culture; Innovations and Digitalization in Food Systems; as well as Policies Coordination and Future Shocks

Reimagining Satsop: Future Life for an Industrial Ruin

Thesis (Master's)--University of Washington, 2020As a strange and alluring artifact of abandoned industry, the Satsop Nuclear Plant has been represented and re-represented by many. This never finished industrial ruin is irreversibly tied to the optimism of 20th century nuclear technology and the project’s subsequent failure, trapped in a state of tension between permanence and decay, the future and the past. Reimagining Satsop examines the site’s entangled histories and questions how this disregarded industrial artifact can transform for future utility. This thesis explores imagination and transience within stigmatized abandoned structures, highlighting the power of perception and the role of architecture in constructing layers of physical strata and collective meaning

Geometry dependence of heating in a U-tube heat exchanger for pasteurization

A serpentine tube heat exchanger is physically constrained by its bend radius. The U-tube bend section of a tubular heat exchanger is thus interesting broadly in terms of fluid flow and heat transfer. This paper presents the tube size dependence of heating profile of this U-tube as is commonly encountered in the design of pasteurizers. Analytical and computational modeling were employed in investigating the heat capacity, heat flux, heating rate and energy use of a U-tube at increasing diameters 9.52, 12.70, 19.05 and 25.40 mm, each at constant 1 mm thickness. SolidWorks 2016 was used in geometric modeling while Ansys v16 was used for transient thermal computational fluid dynamics simulation of the conduit (SS316L) and the product (coconut water). The initial conditions were 5,000 W/(m2-K) convective heat supply at 95 and 92 °C surface temperature for the conduit and the product, respectively. Both the tube and the product were initially at 30 °C. The tube, whose heating profile was independent of size, reached 90 °C in 2.1 s. For the product, as the tube size increases, the heat capacity increases exponentially (Qp = 108.3e0.1831x), the heat flux drops down 57% within 40 s, while both the heating rate (Tt =60 s = -48ln(x) + 183.65) and the energy use (Qu = -29.65lnx + 235.36) drops logarithmically. These results are beneficial to designers and engineers in sizing of heaters, minimizing fouling and optimizing energy efficiency as well as pasteurizer processing capacity

A diagnostic model for green productivity assessment of manufacturing processes

Goal, Scope and Background. Green Productivity (GP) is a new paradigm in sustainable manufacturing where resource conservation and waste minimization constitute the strategy in simultaneously enhancing environmental performance and productivity. This productivity approach to the sustainability of industries requires the adoption of clean production technology and the development of appropriate indicators and instruments to measure environmental performance in a continuous improvement strategy that focuses on the manufacturing stage of the product life cycle. The analysis may be expanded to include the entire life cycle with increasing details on impacts, improvement strategies and indicators. Methods. The study proposes a methodology for GP assessment that integrates the essential components of life cycle assessment (LCA) and multicriteria decision analysis specifically the analytic hierarchy process (AHP). LCA provides a systematic and holistic perspective for GP analysis that spans inventory, impact and improvement assessment. The AHP is utilized as a decision framework and valuation tool for impact and improvement assessment to come up with priority weights. Indicators are derived and measured from a streamlined LCA focused on a number of parameters within the gate-to-gate analysis to demonstrate the GP concept in relation to resource utilization and waste minimization. An input-output approach using a suitable material balance in a scenario analysis provides the basis of GP performance measurement. Results and Conclusion. The diagnostic model is applied on a semiconductor assembly/packaging operation. From the stream-lined life cycle inventory, impact factors were derived for water resource depletion (WRD), energy resource depletion (ERD), human toxicity-air (HTA), human toxicity-land (HTL), human toxicity-water (HTW), aquatic ecotoxicity (ETA) and terrestrial ecotoxicity (ETT). Valuation of impact factors using the AHP showed the high significance of ETT, HTL, WRD and ERD. This especially reflects the impact of the industry on the solid waste problem as a result of emissions to land associated with human toxicity and ecotoxicity effects and the intensive use of water and energy resources. Using scenario analysis, the effect of implementing a process-based improvement technique on a product-specific operation was determined and the highest values in GP are for energy utilization, water utilization and terrestrial ecotoxicity. Recommendation and Perspective. Expert system technology was explored in developing a diagnostic prototype that emulates how human experts diagnose green productivity of manufacturing processes. The aim was to investigate how such a diagnosis could be performed in an intelligent fashion that it is also easily accessible as a decision support for industries. The expert system model will provide flexibility in testing the relationships of environmental performance and productivity parameters as well as in preserving and disseminating valuable human expertise in GP program implementation. This is a continuing research effort that is building the knowledge base for GP assessment. It will include case studies over a wider range or level of detail regarding the impacts and improvement techniques and the other stages of the product life cycle