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Natural light exposure both in flux and spectrum is essential to human health due to its direct relationship with circadian rhythms. Given that light affects visual performance and circadian rhythms differently, metrics need to assess them independently. The aim of this research is to present a new parametric workflow to integrate metrics quantifying the effect of light on circadian rhythm. CircaLight is a new open-source tool for Rhino environment developed as a plugin for Grasshopper. This software enables the calculation of different metrics that quantify the effect of light, both natural and electric, on circadian rhythms, considering the influence of the spectral reflectance of inner surfaces. The CircaLight components can be integrated into Grasshopper plugins such as Solemma or Ladybug tools providing information about the Circadian Stimulus, the Equivalent Melanopic Lux and the Melanopic Photopic ratio, all of which provide current metrics related with circadian rhythms. This research evaluates the reliability of the software presented, quantifying its accuracy by means of other validated software. The results show the accuracy of this new parametric tool with an error under ±10% even in the most unfavorable scenarios.

This work presents the effect of atomic substitution on the MnFe2O4-Na2CO3 thermochemical cycle for H-2 production. The non-oxidative decarbonation/carbonation reaction of the MnFe2O4-Na2CO3 mixture is investigated as the starting reference. Repeated cycling results in a 30% loss of reversibility due to an overall reduction of the reactive interfaces. The substitution of Na2CO3 for Li2CO3 decreases the decarbonation onset temperature by about 100 degrees C, but almost no reversibility is observed during the cycles due to the irreversible Li+ intercalation. The effect of partial Mn substitution for Ca, Ni, and Zn is presented. The 5% Zn mixture shows the best decarbonation/carbonation reversibility and is tested for H-2 production together with MnFe2O4-Na2CO3. The reference mixture produces more H-2 during the first cycle (asymptotic to 1.1 vs. 0.7 mmol/g), but its production drastically drops by two orders of magnitude upon cycling and becomes negligible after 5 cycles. By contrast, the Zn-doped mixture exhibits a stable H-2 production of 0.22 mmol/g with no decreasing trend observed from cycle 2 to cycle 5. As result, in the fifth cycle, the Zn-doped mixture produces 23 times more H-2 than MnFe2O4-Na2CO3. Thermogravimetry and X-ray diffraction confirm that doping with Zn significantly improves the regeneration of the reactants. Acknowledgment This Project is funded by the Department of Economic Devel-opment, Sustainability and Environment of the Basque Govern-ment (CICe 2019-KK-2019/00097-and H2BASQUE-KK-2021/00054) . The authors express their sincere gratitude to Cristina Luengo and Mikel Intxaurtieta for their technical support.

This study presents a combined experimental and theoretical analysis of the stability of NiO nanofluid systems based on a base fluid composed of the eutectic mixture of diphenyl oxide and biphenyl in presence of surfactants. The base fluid is used as a heat transfer fluid in concentrated solar energy and the surfactants were used to analyse the stability of the nanofluids: Benzalkonium Chloride (BAC) and 1-Octadecanethiol (ODT). The stability was analysed experimentally by using UV–vis spectroscopy, particle size and ζ potential measurements. The experimental results indicate that the presence of BAC as surfactant enhance the stability of the nanofluids. Molecular dynamic calculations were performed for three systems (75% BAC, 75% ODT and 75% BAC-75% ODT) to understand the behaviour of both surfactants in the stability of the nanofluid. The analysis of the radial distribution functions (RDFs) and spatial distribution functions (SDFs) revealed a competition of ODT with both base fluid and NiO nanoparticles that explains why the BAC surfactant favoured the formation of stable NiO nanofluid over that with ODT.

Nanofluids could be a promising alternative to the typical heat transfer fluids (HTF) used in concentrating solar power. This study analyses nanofluids based on a typical HTF for concentrating solar power (CSP) applications and NiO nanoparticles. The optimum nanoparticle concentration was determined by analysing the stability of the nanofluids. Some of their properties, such as density, viscosity, isobaric specific heat and thermal conductivity, were characterized to evaluate their performance. Their thermal conductivity increased by up to 96% and the heat transfer coefficient by 50%. Molecular dynamics calculations were performed to explain from a molecular perspective how the presence of equal proportions of two surfactants, benzalkonium chloride (BAC) and 1-Octadecanethiol (ODT), enhanced the thermal properties of the NiO nanofluid. The isobaric specific heat and thermal conductivity values followed the same experimental tendency. The analysis of the radial distribution functions (RDFs) and spatial distribution functions (SDFs) revealed an inner layer of base fluid and surfactant molecules around the NiO cell. This first layer contained BAC molecules at all the temperatures, while ODT was only incorporated at higher temperatures. The exchange of surfactant and base fluid molecules around the NiO as the temperature increases may play an important role in the enhancement of the thermal properties.

One of the possible research lines for improving the Concentrated Solar Power (CSP) technology is the enhancement of the thermophysical properties of the Heat Transfer Fluids (HTF) used. This enhancement leads to reduce costs for producing electricity using this technology. So, this study presents the preparation of nanofluids in which Ag nanoparticles were added to a base fluid composed of a eutectic mixture of diphenyl oxide and biphenyl. The base fluid is a heat transfer fluid commonly used in concentrating solar power plants. The nanofluids were shown to have improved thermal properties, the heat transfer coefficient increasing by up to 6% compared with the base fluid. Thus, their use could lead to enhancements in the overall efficiency of CSP plants. Accordingly, nanofluids were prepared with varying nanoparticle concentrations and their properties were characterized, including their physical and chemical stability, viscosity, isobaric specific heat and thermal conductivity. In addition, molecular dynamic calculations were performed to reach a better understanding of the nanofluid system at a molecular level. The isobaric specific heat and thermal conductivity values followed the same experimental tendency. An analysis of the radial distribution functions (RDFs) and spatial distribution functions (SDFs) shows that there is a first layer of base fluid molecules around the metal in which the oxygen atoms play an important role. This first layer encourages the directionality of the movement in the heart of the nanofluid, which leads to enhanced thermal properties.

This study presents the incorporation of Al-(hydr)oxide species onto the surface of TiO 2 nanoparticles used as photoelectrodes in dye-sensitized solar cells. The semiconductors prepared were comprehensively characterized by means of atomic absorption spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, and UV–vis spectroscopy. The percentages of Al incorporated onto the TiO 2 surface were obtained, the maximum being 6.45 wt.% (Al/TiO 2 ). The presence of Al-(hydr)oxides in the samples was also determined, and was shown not to affect the crystalline phases present, as well as affecting the amount of dye that the semiconductors were able to absorb. These results are evidence of the presence of Al-(hydr)oxide species on the surface. Furthermore, the use of the semiconductors prepared as photoelectrodes in DSSCs led to an increase in open-circuit voltage of up to 16%.

Concentrating solar power (CSP) is one of the most promising environmentally-friendly sources of energy for meeting global energy demands. One line of research intended to improve this kind of solar plants involves increasing the efficiency of the heat transfer fluid (HTF) used, one option being the use of nanofluids. Consequently, this study involves a methodology based on liquid phase exfoliation to prepare stable nanofluids based on 2D MoSe2. A surfactant was used to modify the ratio of the components of the fluid's surface tension in order to obtain a stable nanofluid. Five nanofluids were prepared based on MoSe2 nanosheets, Dowtherm A heat transfer fluid and the Triton X-100 surfactant. The stability of the nanofluids was analysed for a month. Lastly, their thermal properties were characterized. The best nanofluid presented improvements of 7% in isobaric specific heat, 4% in diffusivity and 11% in thermal conductivity. Therefore, these nanofluids would appear to provide a good starting point for creating an alternative to the conventional HTFs used in thermosolar plants. The study highlights the importance of optimizing the parameters of the ratio of the surface tension components, the kind of surfactant added and the methodology used to prepare the nanofluid.

This letter presents a method for the synthesis of copper-doped TiO2 nanoparticles. The semiconductors synthesized were characterized in order to know the composition, crystalline structure, the band gap energy, etc. The nanoparticles obtained have a very low band gap (1.6 eV for 7.5% Cu-doping) compared with the values reported in the literature. The results obtained revealed that internal doping of the TiO2 structure is produced, and that the predominant crystalline phase is anatase. The semiconductors synthesized would be of great use in photocatalytic and photovoltaic applications due to the high specific surface and the low band gap energy values.

To compare the effectiveness of pulse oximetry and fetal electrocardiography in the management of labor with nonreassuring fetal heart rate (NRFHR).This randomized experimental study consisted of two arms. In group 1 we used pulse oximetry and in group 2 we used STAN® technology. The participants in each group were 90 pregnant women with a full-term singleton fetus in cephalic presentation and cardiotocographic tracings compatible with NRFHR. We compared the following variables: rate of cesarean delivery, indications for operative delivery due to NRFHR, and repercussions on the newborn's acid-base status.The two groups differed significantly in the mode of delivery, with a cesarean delivery rate of 47.6% in group 1 vs. 30% in group 2 (p=0.032). The groups did not differ in the indications for ending labor due to NRFHR (62% vs. 61%, NS). In terms of neonatal outcomes, the 1-min Apgar score was 6 or lower in 17.8% of the group 1 neonates vs. 4.44% of the group 2 neonates (p0.001). The groups also differed significantly in umbilical cord vein pH (7.23 vs. 7.27) and pCO₂ (57.27 vs. 46.86) at birth.Fetal electrocardiography with the STAN® 21 system was more effective in detecting good fetal status and thus in identifying cases in which labor could proceed safely. Intrapartum surveillance with the STAN® 21 system reduced the rate of emergency cesarean delivery.

Endocervical margins affected: 44 (15.7%): pre: 32 (14.2%) postmenopausal: 12 (21.8%). Reconizations 17 (6%): premenopausal: 14 (6.2%). Postmenopausal: 3 (5.4%). Hysterectomy postcone: 11 (3.9%): premenopausal: 3 (1.3%). Postmenopausal: 8 (14.5%) hysterectomy indications: 3 microinvasive, 3 persistence CIN 2–3 postcone, 5 Adeno insitu. Conclusions: We found no difference between the 2 groups of preand postmenopausal women in terms of cone histology and number of reconizations made. In the group of postmenopausal women, we found a large number of endocervical margins affected in the histological study of cone and this result would correspond to a greater number of endocervical lesions in menopausal than in premenopausal women. The other major difference was in the postcone hysterectomies related to high-grade lesions with large endocervical affection, which reach a rate of 15%.