The quality of an image captured by the human eye is typically better than that obtained relative to artificial images created by cameras or telescopes. This is because humans have curved retinas. In contrast, conventional imaging cameras have flat sensors that are not well matched to the curved focal surfaces of a camera lens or telescope objective. Thus, the image cannot be at the same focus across the entire sensor field of view. It is hypothesized that as the surface of the sensor approaches the curvature of the camera lens or telescope, the image quality increases. To test this, a commercially available ray tracing software was used. The curvatures were varied from flat (0 mm) to 12 mm. As the curvature reached 9 mm, the Petzval curvature, the quality of the captured images from the camera significantly improved. However, as the curvature increased beyond 9 mm, the quality of the artificial image decreased. In addition, a simulation of a classical Cassegrain telescope was also made. For the telescope, the curvatures were varied from 0 mm to 500 mm. As the curvature approached the telescope’s focal surface curvature of 350 mm, the distortion decreased. In addition to the optical simulations, two images were generated: one with a camera and the other by a reconstruction process. The latter was reconstructed by using the central part of images taken along that curve to create an image. A comparison of these images demonstrates the superior image produced with the latter method. Devices such as cameras and telescopes with curved focal plane array detectors produce images with higher quality than those produced using devices equipped with flat focal plane array detectors.
A new and exciting imaging technique being applied to thin films, nanocoatings, nanogels, and nanoparticle analysis is ultra-low accelerating voltage or ultra-low-landing-energy scanning electron microscopy (ULVSEM). Instrument conditions in this mode are different than with typical SEM observation or contemporary low accelerating voltage (LVSEM) imaging. Hence, the images appear far different due to reduced beam penetration. The landing energy of the primary electron beam can be much lower than LVSEM, it can be reduced to far below 500 electron volts (eV), even as low as 10 eV. Thus, the electron beam range and penetration are reduced tremendously with some unavoidable loss of spatial resolution. Surface details are enhanced, contrast might favorably change, and secondary electron (SE) edge enhancement or “blooming” contributing to measurement uncertainty is greatly reduced, potentially allowing for more precise and new measurements once this imaging mode is fully characterized and accurately modeled. High-resolution field-emission electron sources, improved lens, detector designs, and sample biasing all contribute to the ability to image at such low electron landing energies. The techniques of ULVSEM are discussed, and an application example is presented.
Nation-wide, healthcare-associated infections (HAIs) infect one in every 25 hospital patients, account for more than 100,000 deaths and increase medical costs by around $96-147B, each year. Ultraviolet-C (UV-C) antimicrobial devices are shown to reduce the incidence of many of these HAIs by 35% or more, through the deactivation of the pathogen’s DNA chain following irradiation with a wavelength of ~254 nm. This irradiation does not kill the cells, per se but effectively prevents the cells from multiplying. Clinical case reductions of 30-70% in Clostridium difficile (C. diff.) have been reported with similar results for methicillin-resistant Staphylococcus aureus (MRSA), and others. The methodology works, but, the adoption of UV-C technology by the healthcare industry has been sporadic. This is largely due to the lack of definitive knowledge and uniform performance standards or measures for efficacy to help healthcare managers make informed, credible investment decisions. The leveling of the playing field with scientifically certifiable data of the efficacy of antimicrobial devices will enhance acceptance by the healthcare industry and public, at large, as well as facilitate science-based decision making.
The National Institute of Standards and Technology (NIST) has engaged with the International Ultra Violet Association (IUVA) and its member companies and affiliates to explore ways to develop needed standards, determine appropriate testing protocols, and transfer the technology to help to reduce these inharmonious market conditions. Collaborative efforts are underway to develop science-based answers to the healthcare industry’s questions surrounding standards and measures of device disinfection efficacy, as well as reliability, operations and durability. These issues were recently discussed at the IUVA 2018 America’s Conference in Redondo Beach, CA in several panel sessions. A major output of the sessions was the formation of a formal IUVA Working Group for the development of antimicrobial standards and initiatives for the healthcare industry. The goal of this working group is to provide global guidance, with specific programs and deliverables, on the use of UV technologies and standards to combat HAIs and to further the stated aims of the IUVA on its outreach to the healthcare industry. This paper reviews the strong collaboration between NIST and its industry partners pursuing the development of standards, guidelines and guidance documents related to healthcare applications that include standard methods for validating performance of UV devices and test guidelines for efficacy measurements. In addition, an overview of the issues, problems, and a summary of the needs confronting future growth and success of the UV industry in the Nation’s healthcare application space is provided.
Nanocellulose is a high value material that has gained increasing attention because of its high strength, stiffness, unique photonic and piezoelectric properties, high stability and uniform structure. One of the factors limiting the potential of nanocellulose and the vast array of potential new products is the ability to produce high-volume quantities of this nano-material. However, recent research has demonstrated that nanocellulose can be efficently produced in large volumes from wood at relatively low cost by the incorporation of ionizing radiation in the process stream. Ionizing radiation causes significant break down of the polysaccharides and leads to the production of potentially useful gaseous products such as H2 and CO. Ionizing radiation processing remains an open field, ripe for innovation and application. This presentation will review the strong collaboration between the National Institute of Standards and Technology (NIST) and its academic partners pursuing the demonstration of applied ionizing radiation processing to plant materials for the manufacturing and characterization of novel nanomaterials.
Conference Committee Involvement (8)
Nanoengineering: Fabrication, Properties, Optics, Thin Films, and Devices XXI
20 August 2024 | San Diego, California, United States
Nanoengineering: Fabrication, Properties, Optics, Thin Films, and Devices XX
20 August 2023 | San Diego, California, United States
Nanoengineering: Fabrication, Properties, Optics, Thin Films, and Devices XIX
21 August 2022 | San Diego, California, United States
Nanoengineering: Fabrication, Properties, Optics, Thin Films, and Devices XVIII
1 August 2021 | San Diego, California, United States
Nanoengineering: Fabrication, Properties, Optics, Thin Films, and Devices XVII
24 August 2020 | Online Only, California, United States
Nanoengineering: Fabrication, Properties, Optics, Thin Films, and Devices XVI
11 August 2019 | San Diego, California, United States
Nanoengineering: Fabrication, Properties, Optics, and Devices XV
21 August 2018 | San Diego, California, United States
Nanoengineering: Fabrication, Properties, Optics, and Devices XIV
9 August 2017 | San Diego, California, United States
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.