Search

Given the dire consequences of climate change and the war in Ukraine, decarbonization of electrical power systems around the world must be accomplished, while avoiding recurring blackouts. A good understanding of performance and reliability of different power sources underpins this endeavor. As an energy transition involves different societal sectors, we must adopt a simple and efficient way of communicating the transition's key indicators. Capacity factor (CF) is a direct measure of the efficacy of a power generation system and of the costs of power produced. Since the year 2000, the explosive expansion of solar PV and wind power made their CFs more reliable. Knowing the long-time average CFs of different electricity sources allows one to calculate directly the nominal capacity required to replace the current fossil fuel mix for electricity generation or expansion to meet future demand. CFs are straightforwardly calculated, but they are rooted in real performance, not in modeling or wishful thinking. Based on the current average CFs, replacing 1Wof fossil electricity generation capacity requires installation of 4Wsolar PV or 2Wof wind power. An expansion of the current energy mix requires installing 8.8 W of solar PV or 4.3 W of wind power. [ABSTRACT FROM AUTHOR]

To determine the gas temperature of an alternating current (ac) (50 kHz) arc discharge at atmospheric pressure in air, a Mach-Zehnder type interferometer was built, utilizing an He-Ne ([lambda] = 6328 [Angstrom]) laser source with vertical polarization and a power of 5 mW. Upon introducing the arc discharge into one of the interferometer arms, a displacement of interference fringes takes place with respect to its position without the discharge. Keeping in mind that displacement of the fringes is related to the difference of the optical path with the variation of the refraction index and with temperature change in the discharge zone; the latter was determined from the displacements of the interference fringes. At the center of the discharge channel, a temperature near 3000 K was calculated, diminishing gradually to room temperature toward the discharge borders. This temperature value at the center of the channel agrees with results previously reported in similar discharges. This is an alternate method for the diagnosis of plasma parameters used in the production and treatment of materials. Index Terms--Arc discharge, optical interference, plasma diagnostics.

PURPOSE: To evaluate peripheral refraction and contrast detection sensitivity in pseudophakic patients implanted with a new type of inverted meniscus intraocular lens (IOL) (Art25; Voptica SL) that was designed to provide better peripheral optics. METHODS: One month after cataract surgery, in 87 eyes implanted with the Art25 IOL, peripheral contrast detection sensitivity was measured psychophysically at 40° visual angle, both horizontally and vertically, and compared with a control group of 51 eyes implanted with standard biconvex IOLs. Thirty-one eyes with the Art25 IOL and 28 eyes from the control group were randomly selected to also measure peripheral refraction using a scanning Hartmann-Shack wavefront sensor along 80° in the horizontal meridian. RESULTS: Most patients achieved emmetropia and good visual acuity, and no significant adverse events were observed after cataract surgery with Art25 IOLs. Peripheral contrast detection sensitivity was significantly better (P <.01) in the group with the Art25 IOL in both directions (7.78 ± 3.24 vs 5.74 ± 2.60 vertical, 10.98 ± 5.09 vs 7.47 ± 3.96 horizontal), which was in agreement with the optical quality improvement in the periphery due to a reduction of defocus (1.97 and 1.21 diopters [D] at 40° temporal and nasal sides) and astigmatism (1.17 and 0.37 D at 40° temporal and nasal sides) that was statistically significant (P <.01) from 20° of eccentricity. CONCLUSIONS: Patients implanted with a new inverted meniscus IOL present a reduced amount of peripheral defocus and astigmatism compared to patients implanted with standard biconvex IOLs. This improvement in optical quality leads to better contrast detection sensitivity measured at 40° of eccentricity. [J Refract Surg. 2022;38(4):229–234.] [ABSTRACT FROM AUTHOR]

Step-stack Josephson junctions were fabricated based on high quality epitaxial BSCCO thin films grown on Y-doped bismuth (Bi-22Y2) steps. A high oxygen pressure direct current sputtering method was used to grow Bi-2212 and Bi-22Y2 films. Patterning was done by photolithography combined with non-aqueous Br-ethanol chemical etching. Results illustrate intrinsic Josephson effects in the prepared samples.

The oxidized derivative of graphene named Graphene oxide (GO) are attractive materials as optoelectronic devices due to their optical response in the mid‐infrared wavelength spectral range; however, very large‐scaled synthesis methods and optical characterization are required. Here, GO thin films are fabricated on quartz by implementing simple two‐step pyrolysis processes by using renewable bamboo as source material. The effect of carbonization temperature (TCA) on the compositional, vibrational, and optoelectronic properties of the system are investigated. It was found that as TCA increases, graphite conversion rises, oxygen coverage reduces from 17 % to 4 %, and the band‐gap energy monotonically decreases from 0.30 to 0.11 eV. Theoretical predictions of the energy band‐gap variations with the oxide coverage obtained via density functional theory (DFT) computational simulations agree well with the experimental results, providing evidence of oxygen‐mediated charge‐transport scattering. Interestingly, in the optical response, increased TCA results in a blue‐shift of the absorption and the absorbance spectrum can be correlated with the large size distribution of the graphitic nano‐crystals of the samples. These results suggest that graphene oxide‐bamboo pyroligneous acid (GO) thin films exhibit optoelectronic response useful in developing photodetectors and emitter devices in the mid‐infrared (MIR) spectral range. [ABSTRACT FROM AUTHOR]

Purpose: To validate in the clinic the Adaptive Optics Visual Simulator VAO (Voptica SL, Murcia, Spain). Setting: Laboratory of Clinical Optics, University of Murcia, Spain. Methods: Adaptive optics visual simulators have been widely used in research laboratories for various applications within the visual sciences, however, their use in clinical practice has been limited. Recently, an Adaptive Optics Visual Simulator (VAO, Voptica S.L) has been commercially introduced as a medical device for clinical use. VAO combines optical measurements and visual testing within the same compact instrument. It incorporates a Hartmann‐Shack wave‐front sensor to measure objective refraction and aberrations, together with a spatial light modulator capable of correcting or inducing any optical profile while performing visual testing. In seventy‐six eyes from 38 subjects, subjective refraction (SR) was measured using VAO and trial frame as a gold standard (GS). The agreement of spherical equivalent (M) and cross cylinders (J0 and J45) between SR with VAO and with the GS was estimated using different statistic parameters: 95% confidence limits (CL), Student's t‐test or Wilcoxon Rank Sum and Pearson correlation coefficient (r). Results: There was a strong correlation (r ranged between 0.88 and 0.99) for subjective refraction (M, J0, J45) between GS and VAO and there were not statistically significant differences (p > 0.05). The 95% CL of M, J0 and J45 were ±0.58, ±0.14 and ±0.14 D respectively. In addition to the subjective refraction, the visual acuity was also validated comparing BCVA values from GS with those from VAO, a high correlation (ρ = 0.73) was found for BCVA between both methods. Individual differences in BCVA between both methods were around or below 1 line since 95% CI was ±0.10 LogMAR. Conclusions: Our findings suggest that VAO, the new instrument for vision analysis based on adaptive optics, provides measurements that are comparable to those of the gold standard technique in healthy eyes with 73.7% of the spherical equivalent (M) differences between them within ±0.25 D and 68.4% for BCVA within ±0.05 LogMAR. Thus, subjective refraction found with VAO can be used for prescribing, as a baseline to simulate any optical profile and to customize the selection of the ablation and the IOL design in refractive surgery. [ABSTRACT FROM AUTHOR]

Copyright of CULCyT: Cultura Científica y Tecnológica is the property of Cultura Cientifica y Tecnologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Momento: Revista de Física is the property of Universidad Nacional de Colombia, Departamento de Fisica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: It has been hypothesized that human milk oligosaccharides (HMOs) confer systemic health benefits to breastfed infants; however, plausible mechanisms for some effects, such as systemic immunomodulation, require HMOs to access the bloodstream of the developing infant. While small concentrations of HMOs have been detected in the urine of breastfed infants there are no published studies of these oligosaccharides accessing the plasma compartment of breastfed infants. Here we determined the relative fractions of several ingested HMOs in infant urine and plasma. Plasma from formula-fed infants was used as a control. Methods: Using gas chromatography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry/tandem mass spectrometry (LC/MS/MS), and high performance liquid chromatography (HPLC), we analyzed the urine and plasma from 17 healthy formula-fed infants and 16 healthy breast-fed infants (and the milk from their mothers). Results: Multiple HMOs were detected in the urine and plasma of breastfed infants, but not in formula-fed infants. Levels of 2′-fucosyllactose (2′FL), 3FL and lacto-N-neotetraose (LNnT) in both plasma (r = 0.98, p<0.001; r = 0.75, p = 0.002; r = 0.71, p = 0.004) and urine (r = 0.81, p<0.001; r = 0.56, p = 0.026; NS) correlated significantly with concentrations in the corresponding breast milk. The relative fractions of HMOs were low, 0.1% of milk levels for plasma and 4% of milk levels for urine. Within the breastfed cohort, there were significant differences between secretor and nonsecretor groups in levels of several fucosylated HMOs. Conclusion: At least some ingested HMOs are absorbed intact into the circulation and excreted in the urine and their concentrations in these fluids correlate with levels of the corresponding mother's milk. While relative fractions of absorbed HMOs were low, these levels have been shown to have biological effects in vitro, and could explain some of the postulated benefits of human milk. [ABSTRACT FROM AUTHOR]

The General Estoria, written in the thirteenth century on the initiative of Alfonso X of Castile, is the most ambitious world history of the European Middle Ages. It took more than two decades to translate and combine the more than one hundred Latin, French and Arabic sources into a complex work. After the king's death, and with the work still unfinished, the original redactional team scattered; the Estoria was not copied or read as a whole for the following few centuries, although various sections knew a limited success in the period up the sixteenth century. Until 2009, no complete scholarly edition of the work was available; only the First, Second and sections of the Third had been edited. 2009, a team of philologists (including the authors of this article) published a critical edition of the entire work. The theoretical basis for this edition is presented in this article. [ABSTRACT FROM AUTHOR]

To stimulate discussion around the topic of 'carbohydrates' and health, the Brazilian branch of the International Life Sciences Institute held the 11th International Functional Foods Workshop (12 December 2011) in which consolidated knowledge and recent scientific advances specific to the relationship between carbohydrates and health were presented. As part of this meeting, several key points related to dietary fiber, glycemic response, fructose, and impacts on satiety, cognition, mood, and gut microbiota were realized: 1) there is a need for global harmonization of a science-based fiber definition; 2) low-glycemic index foods can be used to modulate the postprandial glycemic response and may affect diabetes and cardiovascular outcomes; 3) carbohydrate type may influence satiety and satiation; glycemic load and glycemic index show links to memory, mood, and concentration; 4) validated biomarkers are needed to demonstrate the known prebiotic effect of carbohydrates; 5) negative effects of fructose are not evident when human data are systematically reviewed; 6) new research indicates that diet strongly influences the microbiome; and 7) there is mounting evidence that the intestinal microbiota has the ability to impact the gut-brain axis. Overall, there is much promise for development of functional foods that impact the microbiome and other factors relevant to health, including glycemic response (glycemic index/glycemic load), satiety, mood, cognition, and weight management. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Psicología (1669-2438) is the property of Pontificia Universidad Catolica Argentina and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Under some conditions, it is possible for foreign debt to lead to declines in fixed investment within a country. In those cases, economic growth will turn negative. This theoretical possibility is known as the debt overhang hypothesis. This study investigates the debt overhang hypothesis for Mexico during the period between 1980 and 2003. Parameter estimation results offer partial evidence in favor of this hypothesis and simulation results exhibit a high degree of correlation with sample historical data. [ABSTRACT FROM AUTHOR]