Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 220, June 1981

Approximately 137 reports, articles, and other documents introduced into the NASA scientific and technical information system in May 1981 are recorded, covering a variety of topics in aerospace medicine and biology

Electrochemical incineration of wastes

The disposal of domestic organic waste in its raw state is a matter of increasing public concern. Earlier, it was regarded as permissible to reject wastes into the apparently infinite sink of the sea but, during the last 20 years, it has become clear that this is environmentally unacceptable. On the other hand, sewage farms and drainage systems for cities and for new housing developments are cumbersome and expensive to build and operate. New technology whereby waste is converted to acceptable chemicals and pollution-free gases at site is desirable. The problems posed by wastes are particularly demanding in space vehicles where it is desirable to utilize treatments that will convert wastes into chemicals that can be recycled. In this situation, the combustion of waste is undesirable due to the inevitable presence of oxides of nitrogen and carbon monoxide in the effluent gases. Here, in particular, electrochemical techniques offer several advantages including the low temperatures which may be used and the absence of any NO and CO in the evolved gases. Work done in this area was restricted to technological papers, and the present report is an attempt to give a more fundamental basis to the early stages of a potentially valuable technology

Studies on high power ultrasonic microembossing and organic light emitting diodes (OLEDs) for the creation of lab-on-CD devices for sensor related applications

This study demonstrates the application of High Power Ultrasonic Microembossing Technology (HPUMT) in producing microfeatures on polymer substrates. The work reviews a novel method of obtaining flash free and precise microfeatures by manipulating the material density through microcellular foaming. The microfeatures created on the polymer substrates were further characterized by analyzing the feature depth with respect to the critical ultrasonic embossing operating parameters such as embossing heating times (s), embossing amplitude (ym) at a constant embossing trigger force (N). An experiment design was constructed and performed to characterize the parameters on foamed and unfoamed (or regular) versions of polystyrene (PS) and polypropylene (PP) sample materials. Results indicated feature depth was proportional to heating times, amplitude and force. It was also seen the maximum depth was achieved in the shortest cycle times with higher amplitudes and forces of operation. HPUMT was further studied to create functional network of microchannels functioned as reservoirs, reaction chamber and burst or gate valves to form a centrifugal biosensing platform that is also referred to as a lab-on-CD or a bio-CD device. The surface energy of the polymer substrates was increased to enable fluid flow by using a surfactant based organic coating to facilitate hydrophilicity. Using an organic light emitting diode (OLEDs) as an electroluminescence source provided luminescence decay results in good agreement with stern-volmer relationship. The functionality of the OLED-coupled lab-on-CD device was further tested in measuring unknown concentrations of a particular analyte in corn slurry sample which contained numerous contaminants. Combinatorial multianalyte sensing was also made possible on a single bio-CD using a four photodetector (PD) quad preamp disk sensor

Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 138

This special bibliography lists 343 reports, articles, and other documents introduced into the NASA scientific and technical information system in January 1975

Translational Photoacoustic Tomography

Combining optical excitation and ultrasonic detection, photoacoustic tomography (PAT) offers deep imaging with high resolution. With optical excitation, PAT maintains the high contrast of optical imaging. Because of the low scattering of ultrasonic waves in tissue, PAT achieves high spatial resolution at depths. Several advantages make PAT suitable for clinical application, including its scalable penetration and resolution, high optical absorption contrast, fast imaging speed, and ability to perform spectral decomposition. Based on different image reconstruction mechanisms, PAT can be further divided into two embodiments: raster-scanning-based photoacoustic microscopy (PAM) and reconstruction-algorism-based photoacoustic computed tomography (PACT). This dissertation aims to advance the direction of translational PAT, including both PAM and PACT. In Chapter 1, I first explain the basic principles of PAM and PACT and then discuss in detail why they are suitable for translational studies. The chapter concludes with the motivation of my dissertation. Chapter 2 introduces my translational studies in PAM. I first improved the systems lateral resolution and imaging penetration depth by applying an optical clearing technique. With glycerol as an optical clearing agent, the imaging performance of optical resolution PAM (OR-PAM) was greatly enhanced both in vitro and in vivo. Then I applied PAM in quantifying concentrations of blood substances, including red blood cells (RBCs) and bilirubin, and studied related diseases, such as RBC aggregation and jaundice. After building a model to statistically analyze photoacoustic signals for absolute measurement of red blood cell count, I developed multi-wavelength decomposition algorithms and implemented multi-wavelength PA imaging to map bilirubin concentration. Chapter 3 describes studies of complex regional pain syndrome (CRPS) in patients with both OR-PAM and acoustic resolution PAM (AR-PAM). Blood vasculature and oxygen saturation (sO2) were imaged in eight adult patients with CRPS. Patients hands and cuticles were imaged both before and after stellate ganglion block (SGB) for comparison. For all patients, both vascular structure and sO2 could be assessed by PAM. In addition, more vessels and stronger signals were observed after SGB. The results show that PAM can help diagnose and monitor CRPS. Chapter 4 introduces my work on flow measurement both in mice and humans. It first discusses improving the flow measurement accuracy by a new technique cross-correlation-based flowmetry. This technique is based on OR-PAM and can effectively remove the particle size induced measurement error. I demonstrated this technique both in phantom and in vivo experiments in mice. To achieve flow measurement in the optical diffusive regime, I further developed two methods: saline-injection-based and cuffing-based flowmetries. The saline-injection-based method is especially pertinent to monitoring blood flow velocity in patients undergoing intravenous infusion, while the cuffing-based one is suitable for both patients and healthy people. Chapter 5 presents my work on brain imaging, including both mouse and human brains in vivo. To achieve deep mouse brain imaging, I first used a ring transducer array (5 MHz center frequency) with an acoustic reflector. Blood vessels from the bottom of the mouse brain could be imaged, and many key features were detected, such as diving vessels, the superior sagittal sinus, and the posterior cerebral artery. However, the image contrast was not high due to the poor spatial resolutions of the system. To improve the image quality, I later used a linear array system with a 21 MHz center frequency. By rotating the linear array, more striking images were acquired. For the human imaging project, I successfully imaged blood vessel phantoms through an adult human skull. Chapter 6 describes my work on melanoma imaging and depth measurement in patients. Two different systems were used in this project: a handheld AR-PAM system and a handheld linear array system. While the former is cheaper, the latter provides much faster imaging and a larger acceptance angle. With the array system, we successfully imaged melanomas in patients and achieved more accurate depth measurement than incisional biopsy in clinics

Aerosols and Electrical Discharge: 1. Examination of Potential Climate Impact of Mercury Control in Electrostatic Precipitators (ESPs); 2. Instantaneous Bioaerosol Inactivation by Non-Thermal Plasma

One common technology for airstream aerosol (or particulate matter) control is through electrical discharge. Electrical discharge within a neutral gas under atmospheric conditions has two major essential applications related to either its physical or chemical properties. Devices such as electrostatic precipitators (ESPs) are widely applied to reduce stationary PM emission utilizing physical properties of electrical discharge. Separately, the chemical properties of the high voltage discharge can be utilized in several chemical processes, including bioaerosol disinfection. This dissertation had two research focuses related to either the physical or chemical properties of electrical discharge on aerosol control. The first study focus is on potential impact of mercury emission control by powdered activated carbon (PAC) injection to climate change due to low removal efficiency of PAC in ESPs. The injection into the flue gas of PAC is the most mature technology for controlling mercury emissions from coal combustion. However, carbonaceous particles are known to have poor capture in ESPs. Thus, the advent of mercury emissions standards for power plants has the potential for increased emissions of PAC, whose climate change impact is unclear. The study conducted the first comparative measurements of optical scattering and absorption of aerosols comprised of varying mixtures of coal combustion fly ash and PAC. A partially fluidized bed (FB) containing fly ash-PAC admixtures with varying PAC concentrations elutriates aerosol agglomerates. A photo-acoustic extinctiometer (PAX) extractively samples from the FB flow, providing measurements of optical absorption and scattering coefficients of fly ash (FA) alone and FA-PAC admixtures. The results indicate that the increase of carbonaceous particles in the FB emissions can cause a significant linear increase of their mass absorption cross sections. Thus, widespread adoption of activated carbon injection in conjunction with ESPs has the potential to constitute a new source of light absorbing (and climate warming) particle emissions. The second research focus is on packed-bed non-thermal plasma (NTP) discharges and its in-flight inactivation of bacteriophage MS2 and Porcine Reproductive and Respiratory Syndrome virus (PRRSv). To reduce threats of airborne infectious disease outbreaks, there exists a need for control measures that provide effective protection while imposing minimal pressure differential, where NTP can be a solution. In the first part of this study, a low-cost consumer-grade ultrasonic humidifier is proved to consistently suspend dry MS2 aerosols into a constant air flow, and the ultrasonic atomization rate can be monitored in real-time by laser-photodiode light attenuation measurements. In the second part, suspended viral aerosols in a controlled airstream were subjected to NTP exposure within a packed-bed dielectric barrier discharge reactor. Results of plaque assays for MS2 and TCID50 (50% Tissue culture infective dose) for PRRSv showed increasing inactivation of aerosolized viruses (42% to >99%) with increasing applied voltage. No evidence showed that the lipid layer of enveloped PRRSv offered any protection against inactivation, and the virus were inactivated comparably to MS2 by the reactor. Increasing the air flow rate did not significantly impact virus inactivation effectiveness. Activated carbon based ozone filters greatly reduced residual ozone, in some cases down to background levels, while adding less than 20 Pa pressure differential to the 45 Pa differential pressure across the packed bed. The study shows promising results that the prototype packed bed NTP reactor has the potential to reduce airborne infectious disease transmission into indoor environment without significant ozone emission and pressure drop.PHDEnvironmental EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/146103/1/xiatian_1.pd

Physicochemical studies of some compounds

Not availabl

Overview of biofluids and flow sensing techniques applied in clinical practice

This review summarizes the current knowledge on biofluids and the main flow sensing techniques applied in healthcare today. Since the very beginning of the history of medicine, one of the most important assets for evaluating various human diseases has been the analysis of the conditions of the biofluids within the human body. Hence, extensive research on sensors intended to evaluate the flow of many of these fluids in different tissues and organs has been published and, indeed, continues to be published very frequently. The purpose of this review is to provide researchers interested in venturing into biofluid flow sensing with a concise description of the physiological characteristics of the most important body fluids that are likely to be altered by diverse medical conditions. Similarly, a reported compilation of well-established sensors and techniques currently applied in healthcare regarding flow sensing is aimed at serving as a starting point for understanding the theoretical principles involved in the existing methodologies, allowing researchers to determine the most suitable approach to adopt according to their own objectives in this broad field.This research was supported by the Consejo Nacional de Ciencia y Tecnología (CONACYT) of México through Ph.D. grant 472102 and by the Ministerio de Economía y Competitividad through grant FIS2017-89850R.Peer ReviewedPostprint (author's final draft

Index to NASA Tech Briefs, 1975

This index contains abstracts and four indexes--subject, personal author, originating Center, and Tech Brief number--for 1975 Tech Briefs

EXP-SA: Explosives Tracking: A Microsystem for Detection of Bacterial Endospores as Self-Replicating Nucleic Acid Taggants

This proposal presents an integrated research and educational plan directed toward the production, detection, and identification of bacterial endospore taggants for explosive tracking. While the most immediate application of the research is related to stemming the activities of bioterrorists, the anticipated fundamental advances in bioengineering and sensor science and engineering will have significant societal relevance to other applications, including first-responder activities, healthcare, food safety, and pollution avoidance and mitigation. Intellectual Merit The investigators propose to combine bioengineering of Bacillus stearothermophilus endospores with microdevices for sample processing and taggant identification. A surface acoustic wave (SAW) microdroplet mixing/transport/incubator system will be coupled with molecular padlock probe technology for sensitive identification of bioengineered endospores. The specific research tasks are to: (i) Generate a number of different Bacillus spores, each with a unique DNA sequence or sequences spliced into its genome; (ii) Investigate and identify the optimal SAW device designs needed to germinate spores, lyse vegetative bacteria, transport, mix, and heat microdroplet samples; (iii) Design subsystems for DNA isolation; (iv) Develop a fluorescence-based molecular padlock probe system for DNA identification that can operate effectively in conjunction with the SAW fabrication microsystem platform; (v) Fabricate and test the proposed prototype identification system. Broader Impacts Broader impacts will be achieved through the following programs and activities to: (i) Train and interact with high school audiences through two major ongoing programs at University of Maine (UMaine), NSF Research Experiences for Teachers (RET) and the GK-12 Sensors; (ii) Involve undergraduates from Maine and other institutions directly into the research project under the umbrella of the ongoing NSF Research Experience for Undergraduates (REU) program at the UMaine; (iii) Identify appropriate Capstone projects for undergraduates involving cross-disciplinary research and design projects; (iv) Enhance existing graduate level courses (1) Microscale Bioengineering and (2) Design and Fabrication of Acoustic Wave Devices by incorporating research results into each course; (v) Contribute to the interdisciplinary multi-institutional NSF Integrative Graduate Education and Research Traineeship (IGERT) program in functional genomics, which involves UMaine, the Jackson Laboratory, and the Maine Medical Center Research Institute; (vi) Provide thesis topics for M.S. and Ph.D. students; (vii) Disseminate the research and educational material on a project website, and through conferences and printed literature. Project Outcomes ReportNew investigative tools are desperately needed to determine the origin and transit routes of contraband explosive materials, and the individuals who transport them. A powerful strategy for tracking and identifying specific lots of explosives is the incorporation or labeling with pre-and post-detonation identification tags, or taggants. This project involves the production, detection, and identification of bacterial endospore taggants for explosive tracking. It combines bioengineering of environmentally resistant Geobacillus thermoglucosidasius endospores with development of microdevices for sample processing and taggant identification. A surface acoustic wave (SAW) bacterial lysis system is coupled with on-chip fluorescence-based quantitative polymerase chain reaction (PCR) for identification of bioengineered endospores.Geobacillus spores with a unique DNA sequence encoded in well-retained plasmids have been generated. Optimal SAW device structures have been designed, fabricated and tested for lysis of the vegetative bacteria. A number of on-chip structures for multiplex PCR analysis have been created and tested. DNA release and fluorescence-based PCR analysis for identification of specific genomic DNA sequences can now be interfaced to the SAW microsystem platform to comprise an important part of the overall detection system. We anticipate that aspects of this technology will be useful for tracking contraband materials such as explosives, environmental monitoring, and potentially medical diagnostic applications. This project has fostered the multidisciplinary training of numerous undergraduate and graduate students in molecular biology, microbiology, biochemistry, and bioengineering