Magic Lantern Slides 1

According to Charles Musser, Huygens had two key innovations for his magic lantern: 1. Images painted on glass instead of etchings on mirrors. 2. An artificial light source was used instead of the reflection of sunlight. (20) Glass slides (often more than one) with hand drawn images are the standard aesthetic for these slides. They are then usually mounted in rectangular wooden frames approx. 4 x 7 inches with a 3 inch circular opening for the image. (Musser 30) The various mechanisms attached to the images are described in the Object Narrative section.

Magic Lantern Slides 3

According to Charles Musser, Huygens had two key innovations for his magic lantern: 1. Images painted on glass instead of etchings on mirrors. 2. An artificial light source was used instead of the reflection of sunlight. (20) Glass slides (often more than one) with hand drawn images are the standard aesthetic for these slides. They are then usually mounted in rectangular wooden frames approx. 4 x 7 inches with a 3 inch circular opening for the image. (Musser 30) The various mechanisms attached to the images are described in the Object Narrative section.

Solar thermal decoupled water electrolysis process I: Proof of concept

A new concept for a solar thermal electrolytic process was developed for the production of H-2 from water. A metal oxide is reduced to a lower oxidation state in air with concentrated solar energy. The reduced oxide is then used either as an anode or solute for the electrolytic production of H-2 in either an aqueous acid or base solution. The presence of the reduced metal oxide as part of the electrolytic cell decreases the potential required for water electrolysis below the ideal 1.23 V required when H-2 and O-2 evolve at 1 bar and 298 K. During electrolysis, H-2 evolves at the cathode at 1 bar while the reduced metal oxide is returned to its original oxidation state, thus completing the H-2 production cycle. Ideal sunlight-to-hydrogen thermal efficiencies were established for three oxide systems: Fe2O3-Fe3O4, Co3O4-CoO, and Mn2O3-Mn3O4. The ideal efficiencies that include radiation heat loss are as high or higher than corresponding ideal values reported in the solar thermal chemistry literature. An exploratory experimental study for the iron oxide system confirmed that the electrolytic and thermal reduction steps occur in a laboratory scale environment.

Thermal Energy Storage for Solar Power Production

Solar energy is the most abundant persistent energy resource. It is also an intermittent one available for only a fraction of each day while the demand for electric power never ceases. To produce a significant amount of power at the utility scale, electricity generated from solar energy must be dispatchable and able to be supplied in response to variations in demand. This requires energy storage that serves to decouple the intermittent solar resource from the load and enables around-the-clock power production from solar energy. Practically, solar energy storage technologies must be efficient as any energy loss results in an increase in the amount of required collection hardware, the largest cost in a solar electric power system. Storing solar energy as heat has been shown to be an efficient, scalable, and relatively low-cost approach to providing dispatchable solar electricity. Concentrating solar power systems that include thermal energy storage (TES) use mirrors to focus sunlight onto a heat exchanger where it is converted to thermal energy that is carried away by a heat transfer fluid and used to drive a conventional thermal power cycle (e.g., steam power plant), or stored for later use. Several approaches to TES have been developed and can generally be categorized as either thermophysical (wherein energy is stored in a hot fluid or solid medium or by causing a phase change that can later be reversed to release heat) or thermochemical (in which energy is stored in chemical bonds requiring two or more reversible chemical reactions).

The Daughters of Bridget McGhee

When Huxley proposed, Blythe imagined herself fifty years into the future at his funeral. He was such a good man, they’d say. Seventy-two is too young, they’d say. She’d nod and, she had imagined, remember this moment – them lounging in her bed during the early afternoon with the sunlight threatening to burst from behind the drawn shades, him lying on his side with his left arm anchored around her waist, and the tickle of his thumb as he traced circles on her bellybutton. She rubbed her nose against his neck and breathed. His scent was different from that of Walter. Huxley smelled of pears and basil. Walter smelled of leather and soap. She didn’t smell Walter intentionally, of course. He walked into the White Dog the prior day while she was drinking a mint-mocha cappuccino and studying for an exam on medical physiology. The wind whiffed his odor towards her. She didn’t look at him, but she couldn’t stop from inhaling. “People get married after college,” Huxley swung his right leg over and straddled her, forcing her to look at him. “It’s almost been a year since we graduated. It’s what we should do.” She had wondered if he could donate organs if he were seventy-two years old. Not his liver or heart or anything like that, of course, but maybe his eyes. It’d be a shame if they couldn’t preserve his eyes. She noticed them first: they were alert and misty blue, like Santa’s. But then she wondered if eye characteristics like color were even changed during cornea transplants. Walter had plain brown eyes. She hated brown eyes. She told people that she had brown eyes, because they were dark and no one ever looked close enough. Except Huxley. They were at dinner with mutual friends and were talking about eye color, and how they all wished that theirs were like those of the young Afghan girl on the 1985 cover of National Geographic.

Design Simulation for Solar Energy Research and Education

Solar research is primarily conducted in regions with consistent sunlight, severely limiting research opportunities in many areas. Unfortunately, the unreliable weather in Lewisburg, PA, can prove difficult for such testing to be conducted. As such, a solar simulator was developed for educational purposes for the Mechanical Engineering department at Bucknell University. The objective of this work was to first develop a geometric model to evaluate a one sun solar simulator. This was intended to provide a simplified model that could be used without the necessity of expensive software. This model was originally intended to be validated experimentally, but instead was done using a proven ray tracing program, TracePro. Analyses with the geometrical model and TracePro demonstrated the influence the geometrical properties had results, specifically the reflector (aperture) diameter and the rim angle. Subsequently, the two were approaches were consistent with one another for aperture diameters 0.5 m and larger, and for rim angles larger than 45°. The constructed prototype, that is currently untested, was designed from information provided by the geometric model, includes a metal halide lamp with a 9.5 mm arc diameter and parabolic reflector with an aperture diameter of 0.631 meters. The maximum angular divergence from the geometrical model was predicted to be 30 mRadians. The average angular divergence in TraceProof the system was 19.5 mRadians, compared to the sun’s divergence of 9.2 mRadians. Flux mapping in TracePro showed an intensity of 1000 W/m2 over the target plane located 40 meters from the lamp. The error between spectrum of the metal halide lamp and the solar spectrum was 10.9%, which was found by comparing their respective Plank radiation distributions. The project did not satisfy the original goal of matching the angular divergence of sunlight, although the system could still to be used for optical testing. The geometric model indicated performance in this area could be improved by increasing the diameter of the reflector, as well as decreasing the source diameter. Although ray tracing software provides more information to analyze the simulator system, the geometrical model is adequate to provide enough information to design a system.

CH4, CO, and H2O spectroscopy for the Sentinel-5 Precursor mission: an assessment with the Total Carbon Column Observing Network measurements

The TROPOspheric Monitoring Instrument (TROPOMI) will be part of ESA's Sentinel-5 Precursor (S5P) satellite platform scheduled for launch in 2015. TROPOMI will monitor methane and carbon monoxide concentrations in the Earth's atmosphere by measuring spectra of back-scattered sunlight in the short-wave infrared (SWIR). S5P will be the first satellite mission to rely uniquely on the spectral window at 4190–4340 cm−1 (2.3 μm) to retrieve CH4 and CO. In this study, we investigated if the absorption features of the three relevant molecules CH4, CO, and H2O are adequately known. To this end, we retrieved total columns of CH4, CO, and H2O from absorption spectra measured by two ground-based Fourier transform spectrometers that are part of the Total Carbon Column Observing Network (TCCON). The retrieval results from the 4190–4340 cm−1 range at the TROPOMI resolution (0.45 cm−1) were then compared to the CH4 results obtained from the 6000 cm−1 region, and the CO results obtained from the 4190–4340 cm−1 region at the higher TCCON resolution (0.02 cm−1). For TROPOMI-like settings, we were able to reproduce the CH4 columns to an accuracy of 0.3% apart from a constant bias of 1%. The CO retrieval accuracy was, through interference, systematically influenced by the shortcomings of the CH4 and H2O spectroscopy. In contrast to CH4, the CO column error also varied significantly with atmospheric H2O content. Unaddressed, this would introduce seasonal and latitudinal biases to the CO columns retrieved from TROPOMI measurements. We therefore recommend further effort from the spectroscopic community to be directed at the H2O and CH4 spectroscopy in the 4190–4340 cm−1 region.

Alendronate with and without cholecalciferol for osteoporosis: results of a 15-week randomized controlled trial

OBJECTIVE: Many osteoporosis patients have low 25-hydroxyvitamin D (25OHD) and do not take recommended vitamin D amounts. A single tablet containing both cholecalciferol (vitamin D3) and alendronate would improve vitamin D status concurrently, with a drug shown to reduce fracture risk. This study assessed the efficacy, safety, and tolerability of a once-weekly tablet containing alendronate 70 mg and cholecalciferol 70 microg (2800 IU) (ALN + D) versus alendronate 70 mg alone (ALN). METHODS: This 15-week, randomized, double-blind, multi-center, active-controlled study was conducted during a season when 25OHD levels are declining, and patients were required to avoid sunlight and vitamin D supplements for the duration of the study. Men (n = 35) and postmenopausal women (n = 682) with osteoporosis and 25OHD >or= 9 ng/mL were randomized to ALN + D (n = 360) or ALN (n = 357). MAIN OUTCOME MEASURES: Serum 25OHD, parathyroid hormone, bone-specific alkaline phosphatase (BSAP), and urinary N-telopeptide collagen cross-links (NTX). RESULTS: Serum 25OHD declined from 22.2 to 18.6 ng/mL with ALN (adjusted mean change = -3.4; 95% confidence interval [CI]: -4.0 to -2.8), and increased from 22.1 to 23.1 ng/mL with ALN + D (adjusted mean change = 1.2; 95% CI: 0.6 to 1.8). At 15 weeks, adjusted mean 25OHD was 26% higher (p < 0.001, ALN + D versus ALN), the adjusted relative risk (RR) of 25OHD < 15 ng/mL (primary endpoint) was reduced by 64% (incidence 11% vs. 32%; RR = 0.36; 95% CI: 0.27 to 0.48 [p < 0.001]), and the RR of 25OHD < 9 ng/mL (a secondary endpoint) was reduced by 91% (1% vs. 13%; RR = 0.09; 95% CI: 0.03 to 0.23 [p < 0.001]). Antiresorptive efficacy was unaltered, as measured by reduction in bone turnover (BSAP and NTX). CONCLUSION: In osteoporosis patients who avoided sunlight and vitamin D supplements, this once-weekly tablet containing alendronate and cholecalciferol provided equivalent antiresorptive efficacy, reduced the risk of low serum 25OHD, improved vitamin D status over 15 weeks, and was not associated with hypercalcemia, hypercalciuria or other adverse findings, versus alendronate alone.

Nitrogen oxides in the firn air at Summit, Greenland

Measurements of NOx within the snowpack at Summit, Greenland were carried out from June 2008 to July 2010, using a novel system to sample firn air with minimal disruption of the snowpack. These long-term measurements were motivated by the need of improving the representation of air-snow interactions in global models. Results indicated that the NOx budget within the snowpack was on the order of 550 pptv as maximum, and was constituted primarily for NO2. NOx production was observed within the first 50 cm of the snowpack during the sunlight season between February and August. Presence of NOx at larger depths was attributed to high speed wind and vertical transport processes. Production of NO correlated with the seasonal incoming radiation profile, while NO2 maximum was observed in April. These measurements constitute the larger data set of NOx within the firn and will improve the representation of processes driving snow photochemistry at Summit.

Is the development of infectious keratoconjunctivitis in Alpine ibex and Alpine chamois influenced by topographic features?

Infectious keratoconjunctivitis (IKC) caused by Mycoplasma conjunctivae is a widespread ocular affection of free-ranging Caprinae in the Alpine arc. Along with host and pathogen characteristics, it has been hypothesized that environmental factors such as UV light are involved in the onset and course of the disease. This study aimed at evaluating the role of topographic features as predisposing or aggravating factors for IKC in Alpine chamois (Rupicapra rupicapra rupicapra) and Alpine ibex (Capra ibex ibex). Geospatial analysis was performed to assess the effect of aspect (northness) and elevation on the severity of the disease as well as on the mycoplasmal load in the eyes of affected animals, using data from 723 ibex and chamois (583 healthy animals, 105 IKC-affected animals, and 35 asymptomatic carriers of M. conjunctivae), all sampled in the Swiss Alps between 2008 and 2010. An influence of northness was not found, except that ibex with moderate and severe signs of IKC seem to prefer more north-oriented slopes than individuals without corneal lesions, possibly hinting at a sunlight sensitivity consequent to the disease. In contrast, results suggest that elevation influences the disease course in both ibex and chamois, which could be due to altitude-associated environmental conditions such as UV radiation, cold, and dryness. The results of this study support the hypothesis that environmental factors may play a role in the pathogenesis of IKC.

Emerging Areas in Atmospheric Photochemistry

Sunlight is a major driving force of atmospheric processes. A detailed knowledge of atmospheric photochemistry is therefore required in order to understand atmospheric chemistry and climate. Considerable progress has been made in this field in recent decades. This contribution will highlight a set of new and emerging ideas (and will therefore not provide a complete review of the field) mainly dealing with long wavelength photochemistry both in the gas phase and on a wide range of environmental surfaces. Besides this, some interesting bulk photochemistry processes are discussed. Altogether these processes have the potential to introduce new chemical pathways into tropospheric chemistry and may impact atmospheric radical formation.

Spring-summer temperatures reconstructed for northern Switzerland and southwestern Germany from winter rye harvest dates, 1454–1970

This paper presents a unique 517-yr long documentary data-based reconstruction of spring-summer (MAMJJ) temperatures for northern Switzerland and southwestern Germany from 1454 to 1970. It is composed of 25 partial series of winter grain (secale cereale) harvest starting dates (WGHD) that are partly based on harvest related bookkeeping of institutions (hospitals, municipalities), partly on (early) phenological observations. The resulting main Basel WGHD series was homogenised with regard to dating style, data type and altitude. The calibration and verification approach was applied using the homogenous HISTALP temperature series from 1774–1824 for calibration (r = 0.78) and from 1920–1970 for verification (r = 0.75). The latter result even suffers from the weak data base available for 1870– 1950. Temperature reconstructions based on WGHD are more influenced by spring temperatures than those based on grape harvest dates (GHD), because rye in contrast to vines already begins to grow as soon as sunlight brings the plant to above freezing. The earliest and latest harvest dates were checked for consistency with narrative documentary weather reports. Comparisons with other European documentarybased GHD and WGHD temperature reconstructions generally reveal significant correlations decreasing with the distance from Switzerland. The new Basel WGHD series shows better skills in representing highly climate change sensitive variations of Swiss Alpine glaciers than available GHD series.

Mass transport around comets and its impact on the seasonal differences in water production rates

Comets are surrounded by a thin expanding atmosphere, and although the nucleus' gravity is small, some molecules and grains, possibly with the inclusion of ices, can get transported around the nucleus through scattering (atoms/molecules) and gravitational pull (grains). Based on the obliquity of the comet, it is also possible that volatile material and icy grains get trapped in regions, which are in shadow until the comet passes its equinox. When the Sun rises above the horizon and the surface starts to heat up, this condensed material starts to desorb and icy grains will sublimate off the surface, possibly increasing the comet's neutral gas production rate on the outbound path. In this paper we investigate the mass transport around the nucleus, and based on a simplified model, we derive the possible contribution to the asymmetry in the seasonal gas production rate that could arise from trapped material released from cold areas once they come into sunlight. We conclude that the total amount of volatiles retained by this effect can only contribute up to a few percent of the asymmetry observed in some comets.

The first batteryless, solar-powered cardiac pacemaker

BACKGROUND: Contemporary pacemakers (PMs) are powered by primary batteries with a limited energy-storing capacity. PM replacements because of battery depletion are common and unpleasant and bear the risk of complications. Batteryless PMs that harvest energy inside the body may overcome these limitations. OBJECTIVE: The goal of this study was to develop a batteryless PM powered by a solar module that converts transcutaneous light into electrical energy. METHODS: Ex vivo measurements were performed with solar modules placed under pig skin flaps exposed to different irradiation scenarios (direct sunlight, shade outdoors, and indoors). Subsequently, 2 sunlight-powered PMs featuring a 4.6-cm2 solar module were implanted in vivo in a pig. One prototype, equipped with an energy buffer, was run in darkness for several weeks to simulate a worst-case scenario. RESULTS: Ex vivo, median output power of the solar module was 1963 μW/cm2 (interquartile range [IQR] 1940-2107 μW/cm2) under direct sunlight exposure outdoors, 206 μW/cm2 (IQR 194-233 μW/cm2) in shade outdoors, and 4 μW/cm2 (IQR 3.6-4.3 μW/cm2) indoors (current PMs use approximately 10-20 μW). Median skin flap thickness was 4.8 mm. In vivo, prolonged SOO pacing was performed even with short irradiation periods. Our PM was able to pace continuously at a rate of 125 bpm (3.7 V at 0.6 ms) for 1½ months in darkness. CONCLUSION: Tomorrow's PMs might be batteryless and powered by sunlight. Because of the good skin penetrance of infrared light, a significant amount of energy can be harvested by a subcutaneous solar module even indoors. The use of an energy buffer allows periods of darkness to be overcome.

Narrow dust jets in a diffuse gas coma: a natural product of small active regions on comets

Comets often display narrow dust jets but more diffuse gas comae when their eccentric orbits bring them into the inner solar system and sunlight sublimates the ice on the nucleus. Comets are also understood to have one or more active areas covering only a fraction of the total surface active with sublimating volatile ices. Calculations of the gas and dust distribution from a small active area on a comet’s nucleus show that as the gas moves out radially into the vacuum of space it expands tangentially, filling much of the hemisphere centered on the active region. The dust dragged by the gas remains more concentrated over the active area. This explains some puzzling appearances of comets having collimated dust jets but more diffuse gaseous atmospheres. Our test case is 67P/Churyumov–Gerasimenko, the Rosetta mission target comet, whose activity is dominated by a single area covering only 4% of its surface.