100-GHz Phase Switch/Mixer Containing a Slot-Line Transition

A circuit that can function as a phase switch, frequency mixer, or frequency multiplier operates over a broad frequency range in the vicinity of 100 GHz. Among the most notable features of this circuit is a grounded uniplanar transition (in effect, a balun) between a slot line and one of two coplanar waveguides (CPWs). The design of this circuit is well suited to integration of the circuit into a microwave monolithic integrated circuit (MMIC) package. One CPW is located at the input end and one at the output end of the top side of a substrate on which the circuit is fabricated (see Figure 1). The input CPW feeds the input signal to antiparallel flip-chip Schottky diodes connected to the edges of the slot line. Phase switching is effected by the combination of (1) the abrupt transition from the input CPW to the slot line and (2) CPW ground tuning effected by switching of the bias on the diodes. Grounding of the slot metal to the bottom metal gives rise to a frequency cutoff in the slot. This cutoff is valuable for separating different frequency components when the circuit is used as a mixer or multiplier. Proceeding along the slot line toward the output end, one encounters the aforementioned transition, which couples the slot line to the output CPW. Impedance tuning of the transition is accomplished by use of a high-impedance section immediately before the transition

Detection of Teratogenic Substances in Acidic Mine Water Samples Using the Frog Embryo Teratogenesis Assay-xenopus (Fetax)

The Frog Embryo Teratogenesis Assay-Xenopus (FETAX) has been developed to detect teratogenicity of pure compounds and complex mixtures. The application of this system as a quick screen to determine possible teratogenicity of test substances, allows for prioritization of those substances for further testing in established mammalian systems. FETAX provides data on malformation, mortality and inhibition of growth and development that can be statistically analyzed to determine the teratogenic risk of the test compound. This study determined the presence of teratogenic agents in acidic mine water samples from the Tar Creek area of Oklahoma. The results obtained were another step in the validation of FETAX as a useful method of determining agents that cause birth defects.Zoology-Physiolog

Validation and Applications of the Frog Embryo Teratogenesis Assay-Xenopus (Fetax)

Zoolog

Single-Pole Double-Throw MMIC Switches for a Microwave Radiometer

In order to reduce the effect of gain and noise instabilities in the RF chain of a microwave radiometer, a Dicke radiometer topology is often used, as in the case of the proposed surface water and ocean topography (SWOT) radiometer instrument. For this topology, a single-pole double-throw (SPDT) microwave switch is needed, which must have low insertion loss at the radiometer channel frequencies to minimize the overall receiver noise figure. Total power radiometers are limited in accuracy due to the continuous variation in gain of the receiver. High-frequency SPDT switches were developed in the form of monolithic microwave integrated circuits (MMICs) using 75 micron indium phosphide (InP) PIN-diode technology. These switches can be easily integrated into Dicke switched radiometers that utilize microstrip technology

MMIC amplifier based receivers for Earth remote sensing

We have developed amplifier based receivers using Indium Phosphide high electron mobility transistor (HEMT) monolithic microwave integrated circuit (MMIC) technology. These compact receivers are designed with atmospheric temperature and humidity sounding requirements in mind, operating at 100-125 GHz around the 118 GHz oxygen line, and at 160-185GHz near the 183 GHz water line, with average noise temperatures of 1600 and 1200K respectively. They are intended for applications where small volume and power consumption are critical. We will present laboratory data on the noise temperature of these receivers operated at room temperature and preliminary field data

Using technology to promote social connectedness: Insights from the T&Scon project

Loneliness and social isolation can affect anyone, with policymakers recognising the impact of isolation on individual wellbeing and public health. In 2018 the Scottish Government set out its approach to tackling social isolation in A Connected Scotland, a national strategy to achieve a Scotland “where individuals and communities are more connected, and everyone has the opportunity to develop meaningful relationships regardless of age, stage, circumstances, or identity.” A priority of the strategy is to create opportunities for people to connect, with a specific commitment to work with older age groups to “understand how digital technology can add value to their lives in a way that is meaningful”, informing wider work to deliver the Scottish Government’s Digital Strategy for Scotland. The Technology and Social Connectedness (T&Scon) project explored the potential of technology to support social connectedness for adults living in Scotland, producing a toolkit to provide guidance for individuals and organisations on the use of digital technology in building and maintaining social connections. This briefing paper, drawing on the project’s key findings and recommendations, provides a summary of key information for policymakers and practitioners in Scotland, and further afield. Its findings will be of particular interest to those who are developing new ways of keeping in touch, as the risk of social isolation becomes more pronounced in the wake of the global coronavirus pandemic. Key findings A wide range of UK and international technology-based and technology-enabled services exist, designed to support social connectedness, targeted at different adult age user groups. Most technologies used in this way are intended for people living at home although there are technologies in use and in development for the care home sector. Data from the Healthy Ageing in Scotland (HAGIS) study revealed patterns of social connectedness among people over the age of 50 living across Scotland. Patterns of technology use across different groups suggest that those who are least socially connected may also be those least likely to utilise technology to connect with others. Careful evaluation of the target user group is an important factor in the successful adoption of technology-based solutions, breaking down assumptions about who uses technology and who doesn’t, and understanding the risks and opportunities of using technology for this purpose.Briefing based on: T&SCon: Technology and Social Connectedness, Final Report, available online at http://www.tec.sco

The social, health and economic impact of COVID-19 – Healthy Ageing In Scotland (HAGIS):a protocol for a mixed-methods study

Introduction Public health responses to the COVID-19 pandemic have reaped adverse physical, psychological, social and economic effects, with older adults disproportionally affected. Psychological consequences of the pandemic include fear, worry and anxiety. COVID-19 fear may impact individuals’ mitigation behaviours, influencing their willingness to (re)engage in health, social and economic behaviours. This study seeks (1) to develop a robust and evidence-based questionnaire to measure the prevalence of COVID-19 fear among older adults (aged ≥50) in Scotland and (2) to examine the impact of COVID-19 fear on the willingness of older adults to (re)engage across health, social and economic domains as society adjusts to the ‘new normal’ and inform policy and practice. Methods and analysis This mixed-method study includes a large-scale multimodal survey, focus groups and interviews with older adults (aged ≥50) living in Scotland, and an email-based ‘e-Delphi’ consultation with professionals working with older adults. The COVID-19 fear scale was developed and validated using exploratory and confirmatory factor analyses. Survey data will be analysed using descriptive and inferential statistics. Thematic analysis will be used to analyse qualitative data. Survey and qualitative findings will be triangulated and used as the starting point for an ‘e-Delphi’ consensus consultation with expert stakeholders. Ethics and dissemination Ethical approval has been obtained from the University of Stirling for multimodal survey development, fieldwork methodology and data management. Anonymised survey data will be deposited with the UK Data Service, with a link provided via the Gateway to Global Ageing. Qualitative data will be deposited with the University of Stirling online digital repository—DataSTORRE. A dedicated work package will oversee dissemination via a coproduced project website, conference presentations, rapid reports and national and international peer-reviewed journal articles. There is planned engagement with Scottish and UK policy makers to contribute to the UK government’s COVID-19 recovery strategy

Equipment for On-Wafer Testing From 220 to 325 GHz

A system of electronic instrumentation, constituting the equivalent of a two-port vector network analyzer, has been developed for use in on-wafer measurement of key electrical characteristics of semiconductor devices at frequencies from 220 to 325 GHz. A prior system designed according to similar principles was reported in Equipment for On-Wafer Testing at Frequencies Up to 220 GHz (NPO-20760), NASA Tech Briefs, Vol. 25, No. 11 (November 2001), page 42. As one would expect, a major source of difficulty in progressing to the present higher-frequency-range system was the need for greater mechanical precision as wavelengths shorten into the millimeter range, approaching the scale of mechanical tolerances of prior systems. The system (see figure) includes both commercial off-the-shelf and custom equipment. As in the system of the cited prior article, the equipment includes test sets that are extended versions of commercial network analyzers that function in a lower frequency range. The extension to the higher frequency range is accomplished by use of custom frequency-extension modules that contain frequency multipliers and harmonic mixers. On-wafer measurement is made possible by waveguide wafer probes that were custom designed and built for this wavelength range, plus an on-wafer calibration substrate designed for use with these probes. In this case, the calibration substrate was specially fabricated by laser milling. The system was used to make the first on-wafer measurements of a semiconductor device in the frequency range from 220 to 320 GHz. Some of the measurement results showed that the device had gain

A study of the social and physical environment in catering kitchens and the role of the chef in promoting positive health and safety behaviour

This is the account of a mixed method study of chefs and their kitchens in order to identify the nature of their workplace and how this affects their ability to manage health and safety in the kitchen. It included extended periods of observation, monitoring of physical parameters, analysis of records of reported accidents, and a series of reflexive interviews. The findings were integrated and then fed back in a smaller number of second interviews in order to test whether the findings fitted in with the chefs' understanding of their world. Major factors identified included survival in a market environment, the status of the chef (and the kitchen) within organisations, marked autocracy of chefs, and an increasing tempo building up to service time with commensurate heat, noise, and activity. In particular during the crescendo, a threshold shift in risk tolerance was identified. The factors, their interplay, and their implications for health and safety in the catering kitchen are discussed

Characterization and Bioremediation of Birch Condensate

Birch (Betula papyrifera Marsh) condensate collected from a veneer plant in Michigan was analyzed for its major chemical constituents. This condensate contained carbohydrates and lipids. In the lipid fractions, triglycerides were the most abundant component (35-40%), followed by phenolic compounds (30%) and waxes (25-30%). Gas Chromatography-Mass Spectrometry (GC-MS) and Fast Atom Bombardment (FAB) MS were used to identify 14 lipid compounds. A white rot fungus, Phanerochaete chrysosporium [Burdsall-lombard, 5176, HHB-6251], was tested as a means for the bio-remediation of the condensate. P. chrysosporium reduced the total organic content (TOC) of the condensate from 350 ppm to 22 ppm and the color intensity from 0.614 to 0.355 absorbance units, after 2 weeks incubation in a liquid medium containing yeast and peptonc at pH 5