Exploratory Research on MEMS Technology for Air-Conditioning and Heat-Pumps

This report details the efforts to exploit micro-electrical-mechanical-systems (MEMS) and micro device technologies to improve control of multi-channel evaporators by reducing maldistribution among channels, and increase capacity and efficiency of current vapor-compression refrigeration chillers and heat-pumps. Besides summarizing the market potential of MEMS technology for use in evaporators and micro-heat-pumps, the report describes the accomplishments of an experimental investigation of refrigerant-side maldistribution in multi-channel plate heat exchangers (PHE's). A special test facility designed for the purpose of studying the maldistribution of refrigerant in evaporators is described in the report. The facility allows maldistribution caused by either normal superheat temperature control, or induced by the user in controlled amounts, to be measured and quantified. Four different techniques were used to detect the presence of liquid droplets in the stream of superheated vapor at the evaporator exit, an indication of maldistributed flow. They are: Helium-Neon laser, beaded thermocouple, static mixer and newly designed heated MEMS sensor. Comparison of the four techniques shows that the MEMS sensor designed and fabricated in this project has the highest potential for indicating maldistribution, manifested by entrained liquid droplets, in multi-channel evaporators. A complete set of test results in the time and frequency domain is show in graphical form in the appendices. The design, fabrication, calibration, and testing of the MEMS serpentine resistance sensor is also reported, along with a control scheme and strategy for implementing the MEMS sensor in multi-channel evaporator systems

Small Mammal Diversity Varies by Vegetative Cover (Greene County, Ohio)

Although agricultural needs are pressing and crop sales are vital for the local economies in southern Ohio, the resulting clearing of land has removed much of the state’s forests and natural prairies. A variety of species depend upon these habitats that have been reduced resulting in a potentially narrower ecological niche. In this study, we seek to determine the species richness and diversity of small mammals in three habitats (old field, forest, and lawn) and to evaluate factors affecting their activity. Our experimental results supported our hypothesis that the lawn site would have lower diversity than the other two sites. We captured and identified to species a total of 72 individuals in 512 trap nights (14% capture rate) with 30, 33, and 9 in the old field, forest, and lawn sites, respectively. The Shannon Index of diversity (H’) for the lawn was lowest (H’ = 0.49) with just two species observed. In contrast, we documented the greatest diversity (six species, H\u27 = 2.26) in the old field. Intermediate to these two sites we identified five species in the forest (H’ = 1.46). There was also a low community similarity between the plots, suggesting that increased landscape diversity (patches of varying habitat) may also boost landscape biodiversity. We noted that there was no correlation between captures and weather conditions suggesting activity was not impacted by weather in this study. Furthermore, we observed that in the forest, species were captured on the first trap day; however, in the old field and lawn, species were not captured until days 6 and 12 of our 19-day study

The Regularizing Capacity of Metabolic Networks

Despite their topological complexity almost all functional properties of metabolic networks can be derived from steady-state dynamics. Indeed, many theoretical investigations (like flux-balance analysis) rely on extracting function from steady states. This leads to the interesting question, how metabolic networks avoid complex dynamics and maintain a steady-state behavior. Here, we expose metabolic network topologies to binary dynamics generated by simple local rules. We find that the networks' response is highly specific: Complex dynamics are systematically reduced on metabolic networks compared to randomized networks with identical degree sequences. Already small topological modifications substantially enhance the capacity of a network to host complex dynamic behavior and thus reduce its regularizing potential. This exceptionally pronounced regularization of dynamics encoded in the topology may explain, why steady-state behavior is ubiquitous in metabolism.Comment: 6 pages, 4 figure

First-trimester medical abortion with mifepristone 200 mg and misoprostol: a systematic review.

BACKGROUND: The dose of mifepristone approved by most government agencies for medical abortion is 600 mg. Our aim was to summarize extant data on the effectiveness and safety of regimens using the widely recommended lower mifepristone dose, 200 mg, followed by misoprostol in early pregnancy and to explore potential correlates of abortion failure. STUDY DESIGN: To identify eligible reports, we searched Medline, reviewed reference lists of published reports, and contacted experts to identify all prospective trials of any design of medical abortion using 200 mg mifepristone followed by misoprostol in women with viable pregnancies up to 63 days' gestation. Two authors independently extracted data from each study. We used logistic regression models to explore associations between 15 characteristics of the trial groups and, separately, the rates of medical abortion failure and of ongoing pregnancy. RESULTS: We identified 87 trials that collectively included 120 groups of women treated with a regimen of interest. Of the 47,283 treated subjects in these groups, abortion outcome data were reported for 45,528 (96%). Treatment failure occurred in 2,192 (4.8%) of these evaluable subjects. Ongoing pregnancy was reported in 1.1% (499/45,150) of the evaluable subjects in the 117 trial groups reporting this outcome. The risk of medical abortion failure was higher among trial groups in which at least 25% of subjects had gestational age >8 weeks, the specified interval between mifepristone and misoprostol was less than 24 h, the total misoprostol dose was 400 mcg (rather than higher), or the misoprostol was administered by the oral route (rather than by vaginal, buccal, or sublingual routes). Across all trials, 119 evaluable subjects (0.3%) were hospitalized, and 45 (0.1%) received blood transfusions. CONCLUSIONS: Early medical abortion with mifepristone 200 mg followed by misoprostol is highly effective and safe

Spatial and Temporal Variability of Water Quality Parameters in Cedar Lake (Cedarville, Ohio)

Cedar Lake is a man-made lake that is central to Cedarville University’s campus. This focal point of the campus is a source of aesthetic appeal and beauty of Cedarville University. The lake ranges in depth from 0.6-3.7m, is 140m by 150m across, an approximate volume of 40,000 m3 and demonstrates normal capabilities to support fish and other life. There is, however, some concern over Cedar Lake’s level of productivity as undesirable algae blooms are common during warmer months. In October and November 2016 we began to assess the spatial and temporal variability of water chemistry by measuring temperature (℃), dissolved oxygen (DO), ammonium (NH4+), nitrate (NO3-), conductivity, and total dissolved solids. We recorded GPS coordinates of each sample location. We predicted that temperature and DO would be greatest at the surface (due to heating and mixing) and NH4+/NO3- near the shore (due to runoff). We measured the following parameter ranges: temperature of 10.4 - 12.5 (℃), DO = 8.03 - 10.01 mg/L, NH4+ 0.56 - 0.84 (mg/L), NO3- = 0.18 - 0.41 (mg/L), conductivity = 250.4 - 277.6 (mS/cm), and TDS 162.76 - 180.44 (g/L). We found that DO was significantly different (p \u3c 0.05) for both sampling date (October/November) and location (shallow/deep). Using spatial interpolation techniques in ArcGIS we we were able to provide supporting evidence for our hypothesis where NH4+/NO3- levels were greater near the lake’s edge. We also noted a spatial trend in surface DO as it declined from highest values in the northeastern portion of the lake to the lowest values near the outlet

Role of hyperpolarization-activated cyclic nucleotide-gated ion channels in neuropathic pain: a proof-of-concept study of ivabradine in patients with chronic peripheral neuropathic pain.

INTRODUCTION: Hyperpolarization-activated cyclic nucleotide-gated (HCN) ion channels mediate repetitive action potential firing in the heart and nervous system. The HCN2 isoform is expressed in nociceptors, and preclinical studies suggest a critical role in neuropathic pain. Ivabradine is a nonselective HCN blocker currently available for prescription for cardiac indications. Mouse data suggest that ivabradine in high concentrations is equianalgesic with gabapentin. We sought to translate these findings to patients with chronic peripheral neuropathic pain. OBJECTIVES: We sought to translate these findings to patients with chronic peripheral neuropathic pain. METHODS: We adopted an open-label design, administering increasing doses of ivabradine to target a heart rate of 50 to 60 BPM, up to a maximum of 7.5 mg twice daily. All participants scored their pain on an 11-point numerical rating scale (NRS). RESULTS: Seven (7) participants received the drug and completed the study. There was no significant treatment effect on the primary endpoint, the difference between the mean score at baseline and at maximum dosing (mean reduction = 0.878, 95% CI = -2.07 to 0.31, P = 0.1). Exploratory analysis using linear mixed models, however, revealed a highly significant correlation between ivabradine dose and pain scores (χ2(1) = 74.6, P < 0.001), with a reduction of 0.12 ± 0.01 (SEM) NRS points per milligram. The 2 participants with painful diabetic neuropathy responded particularly well. CONCLUSION: This suggests that ivabradine may be efficacious at higher doses, particularly in patients with diabetic neuropathic pain. Importantly, participants reported no adverse effects. These data suggest that ivabradine, a peripherally restricted drug (devoid of central nervous system side effects), is well tolerated in patients with chronic neuropathic pain. Ivabradine is now off-patent, and its analgesic potential merits further investigation in clinical trials.This research was supported by the NIHR Cambridge Biomedical Research Centre (BRC-1215-20014). The authors acknowledge support from the East of England NIHR Clinical Research Network who facilitated identification of participants, and the staff at the Cambridge NIHR Clinical Investigation Ward, who cared for our participants during their visit. The authors are grateful to Mr Abhishek Dixit who built and maintained OpenClinica for data capture. The in-house development and use of FAST-diary are supported by Evelyn Trust (RECORD-Pain) and AAGBI (Anaesthesia-Wiley) research grants

A microfabricated multilayer impedance system for ionic transport characterization in nanocapillary arrays

ABSTRACT A multilayer micro-electrochemical impedance spectroscopic (μ-EIS) system with an integrated Ag/AgCl reference electrode has been developed using MEMS technologies. This μ-EIS system is used to characterize ionic and fluidic transport across nanocapillary array membranes (NCAM), which are comprised of arrays of individual nanopores. Impedance measurements giving magnitude, phase, and I-V characteristics provide insight into the interaction between translocating ions and the electric double layer (EDL) within nanocapillaries due to changes in the surface zeta potential and the ionic charge of the electrolyte. μ-EIS measurements for ionic flow through the NCAM with pore diameters from 10 to 800 nm with an aqueous salt solution indicate that these NCAM behave as nearly ideal RC circuits at electrolyte concentrations on the order of 100 mM, when the EDL within these pores do not overlap. Nyquist plots show an increase in the RC time constant with decreasing salt concentration. Under conditions of EDL overlap, hindered transport in the pores causes deviation from ideal RC circuitlike behaviour with the capacitive component of impedance beginning to dominate

Time-Resolved Measurements and Master Equation Modelling of the Unimolecular Decomposition of CH3OCH2

The rate coefficient for the unimolecular decomposition of CH3OCH2,k(1), has been measured in time-resolved experiments by monitoring the HCHO product. CH3OCH2 was rapidly and cleanly generated by 248 nm excimer photolysis of oxalyl chloride, (ClCO)(2), in an excess of CH3OCH3, and an excimer pumped dye laser tuned to 353.16 nm was used to probe HCHO via laser induced fluorescence. k(1)(T,p) was measured over the ranges: 573-673 K and 0.1-4.3 x 10(18) molecule cm(-3) with a helium bath gas. In addition, some experiments were carried out with nitrogen as the bath gas. Ab initio calculations on CH3OCH2 decomposition were carried out and a transition-state for decomposition to CH3 and H2CO was identified. This information was used in a master equation rate calculation, using the MESMER code, where the zero-point-energy corrected barrier to reaction, Delta E-0,E-1, and the energy transfer parameters, x T-n, were the adjusted parameters to best fit the experimental data, with helium as the buffer gas. The data were combined with earlier measurements by Loucks and Laidler (Can J. Chem. 1967, 45, 2767), with dimethyl ether as the third body, reinterpreted using current literature for the rate coefficient for recombination of CH3OCH2. This analysis returned Delta E-0,E-1 = (112.3 +/- 0.6) kJ mol(-1), and leads to k(1)(infinity)(T) = 2.9 x 10(12) (T/300)(2)(.5) exp(-106.8 kJ mol(-1)/RT). Using this model, limited experiments with nitrogen as the bath gas allowed N-2 energy transfer parameters to be identified and then further MESMER simulations were carried out, where N-2 was the buffer gas, to generate k(1)(T,p) over a wide range of conditions: 300-1000 K and N-2 = 10(12) -10(25) molecule cm(-3). The resulting k(1)(T,p) has been parameterized using a Troe-expression, so that they can be readily be incorporated into combustion models. In addition, k(1)(T,p) has been parametrized using PLOG for the buffer gases, He, CH3OCH3 and N-2.Peer reviewe

Climate Action In Megacities 3.0

"Climate Action in Megacities 3.0" (CAM 3.0) presents major new insights into the current status, latest trends and future potential for climate action at the city level. Documenting the volume of action being taken by cities, CAM 3.0 marks a new chapter in the C40-Arup research partnership, supported by the City Leadership Initiative at University College London. It provides compelling evidence about cities' commitment to tackling climate change and their critical role in the fight to achieve global emissions reductions