Two imaginary researchers, R1 and R2, start talking about hybrid additive manufacturing (AM). Their talk turns into a debate. None of them is less knowledgeable. One cannot teach the other. They are not interested in being part of a Socratic dialogue, where one assumes the role of a teacher, while the other becomes a student. They wonder whether both AM and hybrid AM are the same. Soon they discover that what they understand about the definition is far different than what it is. One says the definition has an inner contradiction; another defends it. One says the name of AM is not right; another shows a brighter picture. One argues that this name can have a negative implication on the education; the other questions the logic. Their discussion includes directed energy deposition, sheet lamination, powder bed fusion, other manufacturing techniques, pre-processing, and post-processing. One says sheet lamination is not AM; another shows how to make a product using sheet lamination. One says selective laser sintering should not be considered AM; another questions the way AM is getting compared with an established subject. At the end, there is no attempt to draw a conclusion; there are only viewpoints, logics, and arguments.

There are two terms in additive manufacturing (AM): shaping and post-processing. These are so prevalent that everyone knows and uses them when required. This has led to their use for different purposes, giving rise to not a single meaning for each term. This has brought into question how much post-processing is acceptable to define AM. This question is tied to another question: what AM stands for—making either all parts or increasingly complex parts. The aim is to answer these questions. The merits of these questions can be better understood if opposing views are instantly available to argue from both sides. Therefore, the present book is written in the form of conversations between two imaginary researchers, named R1 & R2, emphasizing storytelling. It is divided into two parts. The first part consists of five sections; the second one, four sections. These sections are titled Dialogue 1 to Dialogue 9. There are 726 conversations that are continuously numbered. Numbering allows them to be tracked independently of a section number. References for all sections are given together at the end. The title ‘Hybrid additive manufacturing debate’ implies that the conversations are only about hybrid AM (HAM), but this is how it started. Therefore, the first section, i.e., Dialogue 1, is named Hybrid AM. After that, the conversations involved several questions that are not confined only to HAM. Some of the questions are related to the following: the role of post-processing, how much post-processing converts AM into HAM, the difference between simple and complex parts, how to define a complex part, which parts should be preferred in AM, which particular problem defines AM, how AM is different from other techniques, why simple parts should not be fabricated using AM, how the boundary between AM and HAM can be defined, what is the role of AM in shaping, what is shaping, what is the role of manufacturing, is there any difference between AM and an AM process, is AM near-net-shaping technology, is a part sustainable, etc. The conversations, heated exchanges, arguments, counter-arguments, examples, counter-examples, agreement, and disagreement led to a conclusion. The conclusion is that a structural framework is needed—one that defines the external and internal boundaries of AM. The external boundary is to distinguish AM from HAM; the internal one, simple shapes from complex shapes. The framework titled ‘Twin-boundary framework for AM’ is presented in Part 2. The framework has two boundaries or pillars. Dialogue 6 informs about it. Dialogue 7 gives its general description. Dialogues 8 & 9 give detailed descriptions of the first and the second boundary, respectively. The conversations that led to the framework are given in Part 1. Dialogue 2 deals with the meaning of shaping. Dialogue 3 tries to reason why AM should be treated differently from other techniques. Dialogue 4 discusses why simple AM parts should not be made and when they should be made. Dialogue 5 reasons the same from a sustainability perspective. The conversations sometimes go slow, but it helps when the logic is counterintuitive. I hope this book will be helpful to everyone.

Urban noise and soundscape assessment is critical for sustainable, human-centered city planning. A comprehensive overview of key standards is essential to ensure consistent measurements, enable cross-study comparisons, and support practical applications. This review examines standards from the American National Standards Institute/Acoustical Society of America (ANSI/ASA), ASTM International, and the International Organization for Standardization (ISO), highlighting their principles, methodologies, and roles in evaluating urban acoustic environments. It discusses how these standards facilitate accurate noise quantification, capture human perceptual responses, and guide soundscape design and management across occupational, community, and experimental settings. Standardized questionnaires, rating scales, and perceptual frameworks are also reviewed. Finally, this paper identifies gaps in current guidance, including limited approaches to continuous monitoring, cultural adaptation, multisensory interactions, and integration with urban planning.

This review paper examines innovative urban design strategies for sustainable noise management through a structured analysis framed by ten guiding questions. It begins with an overview of conventional noise assessment technologies and progresses to advanced mitigation approaches. Core principles of sustainable urban design are explored, alongside evaluations of urban and transportation planning, traffic-reduction measures, green infrastructure, and resilient architectural strategies. Material innovations and modern noise-control technologies are presented as complementary solutions. Community-based methods, including citizen science and participatory planning, are highlighted for fostering inclusive governance. The discussion concludes by addressing key challenges and future directions, underscoring interdisciplinary collaboration to transform urban noise pollution into opportunities for healthier, more livable cities.

The merits of these questions can be better understood if opposing views are instantly available to argue from both sides. Therefore, the present book is written in the form of conversations between two imaginary researchers, named R1 & R2, emphasizing storytelling. It is divided into two parts. The first part consists of five sections; the second one, four sections. These sections are titled Dialogue 1 to Dialogue 9. There are 726 conversations that are continuously numbered. Numbering allows them to be tracked independently of a section number. References for all sections are given together at the end. The title ‘Hybrid additive manufacturing debate’ implies that the conversations are only about hybrid AM (HAM), but this is how it started. Therefore, the first section, i.e., Dialogue 1, is named Hybrid AM. After that, the conversations involved several questions that are not confined only to HAM. Some of the questions are related to the following: the role of post-processing, how much post-processing converts AM into HAM, the difference between simple and complex parts, how to define a complex part, which parts should be preferred in AM, which particular problem defines AM, how AM is different from other techniques, why simple parts should not be fabricated using AM, how the boundary between AM and HAM can be defined, what is the role of AM in shaping, what is shaping, what is the role of manufacturing, is there any difference between AM and an AM process, is AM near-net-shaping technology, is a part sustainable, etc. The conversations, heated exchanges, arguments, counter-arguments, examples, counter-examples, agreement, and disagreement led to a conclusion. The conclusion is that a structural framework is needed—one that defines the external and internal boundaries of AM. The external boundary is to distinguish AM from HAM; the internal one, simple shapes from complex shapes. The framework titled ‘Twin-boundary framework for AM’ is presented in Part 2. The framework has two boundaries or pillars. Dialogue 6 informs about it. Dialogue 7 gives its general description. Dialogues 8 & 9 give detailed descriptions of the first and the second boundary, respectively. The conversations that led to the framework are given in Part 1. Dialogue 2 deals with the meaning of shaping. Dialogue 3 tries to reason why AM should be treated differently from other techniques. Dialogue 4 discusses why simple AM parts should not be made and when they should be made. Dialogue 5 reasons the same from a sustainability perspective.

Drug delivery has been significantly advanced through the development of microfluidic technologies, which enable precise manipulation of fluid inflow at the microscale. These systems grease the localized administration of chemotherapeutic agents, thereby reducing systemic toxin in cancer treatment. In this study, a crispy microchannel was designed and anatomized for the controlled distribution of doxorubicin reprised in liposomal carriers. Numerical simulations were performed using COMSOL Multiphysics to estimate key inflow parameters such as velocity distribution, shear stress, and flyspeck circles. The crispy channel figure bettered mixing uniformity and assured smooth inflow while maintaining shear stress within safe physiological limits(0.5 Pa). The optimized design demonstrates implicit for enhanced remedial effectiveness, minimized flyspeck aggregation, and better localized medicine delivery in microfluidic- grounded chemotherapy systems

The pursuit of sustainable design has made strides in improving building practices, yet traditional approaches often fall short in addressing the holistic needs of both the environment and human well-being. This research delves into the emerging field of regenerative design, which extends beyond sustainability by seeking to restore and enhance ecological and human systems. By integrating regenerative principles into indoor environments, this study evaluates their impact on indoor environmental quality (IEQ). Through a comprehensive literature review, the research demonstrates that regenerative design can significantly enhance air quality, thermal comfort, lighting, and acoustics, ultimately creating healthier and more productive indoor spaces. This paper also discusses potential challenges and outlines future research directions to further advance the application of regenerative design in building practices.

The pursuit of sustainable design has made strides in improving building practices, yet traditional approaches often fall short in addressing the holistic needs of both the environment and human well-being. This research delves into the emerging field of regenerative design, which extends beyond sustainability by seeking to restore and enhance ecological and human systems. By integrating regenerative principles into indoor environments, this study evaluates their impact on indoor environmental quality (IEQ). Through a comprehensive literature review, the research demonstrates that regenerative design can significantly enhance air quality, thermal comfort, lighting, and acoustics, ultimately creating healthier and more productive indoor spaces. This paper also discusses potential challenges and outlines future research directions to further advance the application of regenerative design in building practices.

This manuscript offers a concise overview of paper microfluidics, emphasizing its sustainable sensing applications in healthcare, environmental monitoring, and food safety. Researchers have developed innovative sensing platforms for detecting pathogens, pollutants, and contaminants by leveraging the paper’s unique properties, such as biodegradability and affordability. These portable, low-cost sensors facilitate rapid diagnostics and on-site analysis, making them invaluable tools for resource-limited settings. This review discusses the fabrication techniques, principles, and applications of paper microfluidics, showcasing its potential to address pressing challenges and enhance human health and environmental sustainability.

In the past decade, the term 'global aging' has gained much attention among researchers, policymakers, civil societies, and governments worldwide. The continuous decline in fertility rates and increased life expectancy have resulted in an ongoing demographic transition where the share of adults aged 65 or older is increasing and outnumbering children younger than five years. In the United States and other developed countries, this rapid demographic transition is expected to continue to strain the existing health infrastructure as it becomes increasingly challenging to ensure healthy living environments for older adults. The ten questions and answers in this paper have been prepared by experts from gerontology, geriatrics, architectural engineering, and senior living operations to inform and characterize the current continuum of living environments and communities available to older adults. They also identify the common elements that influence the environmental needs of older adults and highlight factors (such as technical assistance, health equity gaps, and caregiver workforce development) that challenge the future of smart and healthy built environments for older adults. A special focus has been placed on contextualizing indoor environmental quality (IEQ) elements and smart building technologies for older individuals, caregivers, and their various requirements (perhaps in their own homes and communities). Together, these viewpoints create a new paradigm to assist in designing and managing intelligent, healthy built environments that respond to human demands. Although this paper focuses on factors in the United States, others can benefit from the framework incubated upon these experiences, making this effort relevant toward addressing global opportunities in environments for older adults.

Exploring the potential of sound absorption is foremost for improving room acoustics and unleashing the power of noise remediation. Acoustic metamaterials are considered promising candidates for tunable broadband sound absorption in the low-to-high frequency range. In this work, an acoustic meta-absorber with multi-order Helmholtz resonator cavities is proposed. The meta-absorber unit cell comprises multiple disks, spacers, and a bottom cavity arranged in a series configuration. Therefore, the assembled acoustic meta-absorber is reconfigurable to have different absorption characteristics. Experimental results demonstrate that the proposed meta-absorber unit cell exhibits high sound absorption, with multiple absorption peaks observed within the 80-1600 Hz frequency range. Additionally, tunable broadband and quasi-perfect absorption (≥0.9) can be achieved at low frequencies (≤600 Hz) by adjusting the positions of individual disks and other structural parameters. Furthermore, a feedforward network-design approach based on machine learning models is proposed and experimentally demonstrated for the meta-absorber. Two types of meta-absorber features and different machine learning algorithms, including artificial neural network (ANN), k-Nearest Neighbor (kNN), and radial basis function neural network (RBFN), are utilized to compare their predictive abilities. The implementation of machine learning models allows for efficient design optimization of the meta-absorber's geometrical parameters to achieve specific functionalities without relying on physical models. The geometrical parameters are adaptively tuned during the design process to enhance sound absorption performance, particularly at low frequencies. The predicted sound absorption values are compared with the experimental results, and among the machine learning algorithms employed, ANN demonstrates the best performance, followed by the kNN method.

Autism is a set of complex neurobehavioral conditions that involve, among other characteristics, hypo/hypersensitive responses to any sensory input, usually referred to as sensory processing disorder. The most common sensory difference associated with autistic individuals is an over or under response to visuals, touch, smells, tastes, balance, and sounds when compared to neurotypical individuals. Among these, auditory sensitivity has a significant influence. Research studies to date have revealed that autistic individuals are highly susceptible to surrounding sounds, and show that certain noises, such as loud sounds, classroom bells, sirens, the radio or the TV, and traffic noise, may induce uncomfortable and distracting behavior. In this study, we investigated the acoustic environment of classrooms/facilities designed for a more inclusive education. A number of room acoustic descriptors, such as reverberation time (RT), speech clarity (C50), speech transmission index (STI), sound levels, and auditory strength (S/N ratio) were measured in this regard. The experimental measurements were performed in several rooms and facilities focusing on autistic individuals in Campinas, São Paulo, in Brazil and in Omaha, Nebraska, in the United States.

The promising field of organic electronics has ushered in a new era of biosensing technology, thus offering a promising frontier for applications in both medical diagnostics and environmental monitoring. This review paper provides a comprehensive overview of organic electronics’ remarkable progress and potential in biosensing applications. It explores the multifaceted aspects of organic materials and devices, thereby highlighting their unique advantages, such as flexibility, biocompatibility, and low-cost fabrication. The paper delves into the diverse range of biosensors enabled by organic electronics, including electrochemical, optical, piezoelectric, and thermal sensors, thus showcasing their versatility in detecting biomolecules, pathogens, and environmental pollutants. Furthermore, integrating organic biosensors into wearable devices and the Internet of Things (IoT) ecosystem is discussed, wherein they offer real-time, remote, and personalized monitoring solutions. The review also addresses the current challenges and future prospects of organic biosensing, thus emphasizing the potential for breakthroughs in personalized medicine, environmental sustainability, and the advancement of human health and well-being.

This study presents a compact, lightweight, and reconfigurable acoustic metatile for sound mitigation applications. The metatile prototype is designed based on a circular maze-like acoustic metastructure, which utilizes a space-coiling technique for enhanced acoustic performance in low-to-mid frequencies. The proposed labyrinthine acoustic metadisk structure comprises a central hollow front face sheet and two coiling-up backing cavities. Experimental results show that the metadisk has high absorption peaks of 0.81 and 0.75 at 574 and 1436 Hz, respectively, and exhibits high sound transmission loss (STL) values ( ≥25 dB) in separate wide frequency bands between 100–580 Hz and 820–1600 Hz. Based on the metadisk samples, metatiles are constructed, which are 30.5 × 30.5 cm 2 in size. The acoustic performance of these metatiles is investigated in two distinct scenarios. Two prototypes of the acoustic metatile are presented: the metacage and the metapanel. The metacage is a cubical box-shaped structure constructed using five metatiles, which showed a wideband insertion loss of ≥10 dB in 200–16 000 Hz and ≥20 dB over 400–5000 Hz. On the other hand, the metapanel is constructed using nine metatiles, which exhibited STL values of >20 dB over 125–5000 Hz and had a sound transmission class rating of 34. The study highlights the potential of circular maze-like space-coiling-based acoustic disk metastructures to be reconfigured into metatiles and assembled into a metacage or metapanel for practical sound mitigation applications.