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3D-bioprinted skin-mimicking phantoms with skin colors ranging across the Fitzpatrick scale are reported. These tools can help understand the impact of skin phototypes on biomedical optics. Synthetic melanin nanoparticles of different sizes (70-500 nm) and clusters are fabricated to mimic the optical behavior of melanosome. The absorption coefficient and reduced scattering coefficient of the phantoms are comparable to real human skin. Further the melanin content and distribution in the phantoms versus real human skins are validated via photoacoustic (PA) imaging. The PA signal of the phantom can be improved by: 1) increasing melanin size (3-450-fold), 2) increasing clustering (2-10.5-fold), and 3) increasing concentration (1.3-8-fold). Then, multiple biomedical optics tools (e.g., PA, fluorescence imaging, and photothermal therapy) are used to understand the impact of skin tone on these modalities. These well-defined 3D-bioprinted phantoms may have value in translating biomedical optics and reducing racial bias.

BackgroundInsect biomass is a sustainable alternative to traditional animal feeds, particularly when insects are produced on low-value high-volume agricultural by-products. Seven samples of almond by-product (hulls and shells) were obtained from processors in California and investigated for larvae production. Experiments were completed with and without larvae and spent substrate samples were assessed for their potential as soil amendments based on standard compost quality indicators.ResultsOn average, specific larvae growth and average larval harvest weight were 158% and 109% higher, respectively, when larvae were reared on Monterey and pollinator hulls compared to nonpareil hulls and mixed shells. Larvae methionine and cystine contents were highest when larvae were reared on Monterey hulls and mixed shells, respectively. Available phytonutrients in spent substrate were affected by feedstock sample and larvae rearing. Spent nonpareil substrate without larvae had the highest NH4 -N levels and spent pollinator substrate incubated without larvae had the highest PO4 -P levels. Spent mixed shell substrate had the lowest availability of phytonutrients.ConclusionThe findings demonstrate that by-product composition has a significant impact on larvae growth and the properties of the spent substrate, and that spent substrate from larvae rearing requires further stabilization before application as a soil amendment. © 2020 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

BackgroundThe increasing production of almonds worldwide has resulted in the significant generation of byproduct streams that require end uses. One potential use for byproducts is for cultivation of additional food sources including insects. Studies were performed to determine if black soldier fly larvae (Hermetia illucens L.) could be cultivated on almond byproducts (hulls and shells) and to examine the effect of aeration and moisture on larvae growth and hull composition.ResultsIncreasing aeration from 0.04 to 0.36 mL min-1 g dry weight-1 tripled the harvest weight of larvae and increased larvae yield by a factor of five. Larvae calcium content increased by 18% with an increase in aeration from 0.04 to 0.95 mL min-1 g dry weight-1 . Moisture content also affected harvest dry weight and yield; increasing moisture content from 480 g kg-1 (wet basis) to 680 g kg-1 increased harvest weight by 56% and yield by a factor of 2. Variables did not affect larvae methionine and cysteine content. Low moisture content and aeration rate yielded an environment that supported microbial consumption of hulls over larvae consumption and growth.ConclusionsThe results demonstrate that almond hulls are a suitable feedstock for larvae production under controlled management of moisture content and aeration. © 2018 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Solar-powered electrochemical production of hydrogen through water electrolysis is an active and important research endeavor. However, technologies and roadmaps for implementation of this process do not exist. In this perspective paper, we describe potential pathways for solar-hydrogen technologies into the marketplace in the form of photoelectrochemical or photovoltaic-driven electrolysis devices and systems. We detail technical approaches for device and system architectures, economic drivers, societal perceptions, political impacts, technological challenges, and research opportunities. Implementation scenarios are broken down into short-term and long-term markets, and a specific technology roadmap is defined. In the short term, the only plausible economical option will be photovoltaic-driven electrolysis systems for niche applications. In the long term, electrochemical solar-hydrogen technologies could be deployed more broadly in energy markets but will require advances in the technology, significant cost reductions, and/or policy changes. Ultimately, a transition to a society that significantly relies on solar-hydrogen technologies will benefit from continued creativity and influence from the scientific community.

The Andes is the largest undeveloped geothermal region in the world. The Chilean case is the most puzzling because the country is largely dependent on imported fuels causing, among other issues, high energy prices and energy dependency. But even though it has large quantities of geothermal resources which have been explored since the 1920s, no geothermal power plant has been constructed yet. The barriers for geothermal development in Chile have not been studied in detail and limited information is available about the real economic feasibility of geothermal power generation and whether effective incentives are needed for its development. In this study we present an integrated analysis of geoscientific, economic, historical and regulatory aspects of geothermal development in Chile based on the compilation of new and previously published data. Through a survey of key participants from government institutions, industry and academia we identified the main perceived advantages, barriers, and efficient incentives. The absence of clear medium-to-long term energy policies and a lack of government incentives for companies to overcome financial risk are perceived as the main barriers. Additionally, we calculated the estimated average Levelized Costs of Energy (LCoE) of geothermal electricity generation using different scenarios to illustrate the potential impact of possible government policies. At present conditions and without incentives we estimated a base case geothermal LCoE in Chile which would be "near competitive" compared to the average contract prices. Further analysis would be needed to estimate the effect of different policy incentives more rigorously. Finally, we propose some guidelines for geothermal stakeholders to encourage geothermal power development; these might prove useful to other Andean and developing countries as well.

The Andes is the largest undeveloped geothermal region in the world. The Chilean case is the most puzzling because the country is largely dependent on imported fuels causing, among other issues, high energy prices and energy dependency. But even though it has large quantities of geothermal resources which have been explored since the 1920s, no geothermal power plant has been constructed yet. The barriers for geothermal development in Chile have not been studied in detail and limited information is available about the real economic feasibility of geothermal power generation and whether effective incentives are needed for its development. In this study we present an integrated analysis of geoscientific, economic, historical and regulatory aspects of geothermal development in Chile based on the compilation of new and previously published data. Through a survey of key participants from government institutions, industry and academia we identified the main perceived advantages, barriers, and efficient incentives. The absence of clear medium-to-long term energy policies and a lack of government incentives for companies to overcome financial risk are perceived as the main barriers. Additionally, we calculated the estimated average Levelized Costs of Energy (LCoE) of geothermal electricity generation using different scenarios to illustrate the potential impact of possible government policies. At present conditions and without incentives we estimated a base case geothermal LCoE in Chile which would be "near competitive" compared to the average contract prices. Further analysis would be needed to estimate the effect of different policy incentives more rigorously. Finally, we propose some guidelines for geothermal stakeholders to encourage geothermal power development; these might prove useful to other Andean and developing countries as well.

Recent accurate measurements of cosmic-ray (CR) species by ATIC-2, CREAM, and PAMELA reveal an unexpected hardening in the proton and He spectra above a few hundred GeV, a gradual softening of the spectra just below a few hundred GeV, and a harder spectrum of He compared to that of protons. These newly discovered features may offer a clue to the origin of high-energy CRs. We use the Fermi Large Area Telescope observations of the γ-ray emission from Earth's limb for an indirect measurement of the local spectrum of CR protons in the energy range ∼90  GeV-6  TeV (derived from a photon energy range 15 GeV-1 TeV). Our analysis shows that single power law and broken power law spectra fit the data equally well and yield a proton spectrum with index 2.68±0.04 and 2.61±0.08 above ∼200  GeV, respectively.

Summary: Photocatalytic transformation of biomass into value-added chemicals coupled with co-production of hydrogen provides an explicit route to trap sunlight into the chemical bonds. Here, we demonstrate a rational design of Zn1-xCdxS solid solution homojunction photocatalyst with a pseudo-periodic cubic zinc blende (ZB) and hexagonal wurtzite (WZ) structure for efficient glucose conversion to simultaneously produce hydrogen and lactic acid. The optimized Zn0.6Cd0.4S catalyst consists of a twinning superlattice, has a tuned bandgap, and displays excellent efficiency with respect to hydrogen generation (690 ± 27.6 μmol·h−1·gcat.−1), glucose conversion (~90%), and lactic acid selectivity (~87%) without any co-catalyst under visible light irradiation. The periodic WZ/ZB phase in twinning superlattice facilitates better charge separation, while superoxide radical (⋅O2-) and photogenerated holes drive the glucose transformation and water oxidation reactions, respectively. This work demonstrates that rational photocatalyst design could realize an efficient and concomitant production of hydrogen and value-added chemicals from glucose photocatalysis.

The benefits that mathematical sciences from statistics can generate for companies are still unknown. However, thanks to the technological advances that have taken place in recent decades, we can observe a rapprochement of business environments to this type of instrument. To analyze the most outstanding aspects that statistics offers for the management oof information at the enterprise level, the data collected after consulting research in Spanish and English are presented below. The results presented are a guide for entrepreneurs, students, and those who are considering the option of starting a business idea, to choose one of the above options as a support to achieve better results. [ABSTRACT FROM AUTHOR]