The Experts below are selected from a list of 56814 Experts worldwide ranked by ideXlab platform
Hiroshi Osada - One of the best experts on this subject based on the ideXlab platform.
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Modeling of the thermoregulation system in the skunk cabbage: Symplocarpus foetidus.
Physical review. E Statistical nonlinear and soft matter physics, 2007Co-Authors: Ken Takahashi, Yoshihiko Onda, Kikukatsu Ito, Takanori Ito, Shigeki Chiba, T. Endo, Hiroshi OsadaAbstract:This paper presents a model of the thermoregulation system of the spadix of skunk cabbage Symplocarpus foetidus which regulates its internal temperature at around 20 degrees C during flowering even when the ambient air temperature drops below freezing. From the temperature responses of the spadix to changing ambient air temperature, we assumed that the thermoregulation system of the spadix is probably one of negative feedback control. The feedback signals are based on the rate of temperature change of the spadix over time. A signal is factored into the Biochemical Energy generator, and becomes Biochemical Energy, some of which becomes heat. Comparing our proposed model temperature responses and those of the living spadix, we found good agreement. In the process of engineering the model, the existence of two regulatory pathways in the thermoregulation system was simulated, and our proposed model appears to provide the necessary elements to explain the fundamental mechanism of the thermoregulation system of S. foetidus.
Mirco Migliavacca - One of the best experts on this subject based on the ideXlab platform.
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bigleaf an r package for the calculation of physical and physiological ecosystem properties from eddy covariance data
PLOS ONE, 2018Co-Authors: Jurgen Knauer, Tarek S Elmadany, Sonke Zaehle, Mirco MigliavaccaAbstract:We present the R package bigleaf (version 0.6.5), an open source toolset for the derivation of meteorological, aerodynamic, and physiological ecosystem properties from eddy covariance (EC) flux observations and concurrent meteorological measurements. A ‘big-leaf’ framework, in which vegetation is represented as a single, uniform layer, is employed to infer bulk ecosystem characteristics top-down from the measured fluxes. Central to the package is the calculation of a bulk surface/canopy conductance (Gs/Gc) and a bulk aerodynamic conductance (Ga), with the latter including formulations for the turbulent and canopy boundary layer components. The derivation of physical land surface characteristics such as surface roughness parameters, wind profile, aerodynamic and radiometric surface temperature, surface vapor pressure deficit (VPD), potential evapotranspiration (ET), imposed and equilibrium ET, as well as vegetation-atmosphere decoupling coefficients, is described. The package further provides calculation routines for physiological ecosytem properties (stomatal slope parameters, stomatal sensitivity to VPD, bulk intercellular CO2 concentration, canopy photosynthetic capacity), Energy balance characteristics (closure, Biochemical Energy), ancillary meteorological variables (psychrometric constant, saturation vapor pressure, air density, etc.), customary unit interconversions and data filtering. The target variables can be calculated with a different degree of complexity, depending on the amount of available site-specific information. The utilities of the package are demonstrated for three single-level (above-canopy) eddy covariance sites representing a temperate grassland, a temperate needle-leaf forest, and a Mediterranean evergreen broadleaf forest. The routines are further tested for a two-level EC site (tree and grass layer) located in a Mediterranean oak savanna. The limitations and the ecophysiological interpretation of the derived ecosystem properties are discussed and practical guidelines are given. The package provides the basis for a consistent, physically sound, and reproducible characterization of biometeorological conditions and ecosystem physiology, and is applicable to EC sites across vegetation types and climatic conditions with minimal ancillary data requirements.
Ken Takahashi - One of the best experts on this subject based on the ideXlab platform.
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Modeling of the thermoregulation system in the skunk cabbage: Symplocarpus foetidus.
Physical review. E Statistical nonlinear and soft matter physics, 2007Co-Authors: Ken Takahashi, Yoshihiko Onda, Kikukatsu Ito, Takanori Ito, Shigeki Chiba, T. Endo, Hiroshi OsadaAbstract:This paper presents a model of the thermoregulation system of the spadix of skunk cabbage Symplocarpus foetidus which regulates its internal temperature at around 20 degrees C during flowering even when the ambient air temperature drops below freezing. From the temperature responses of the spadix to changing ambient air temperature, we assumed that the thermoregulation system of the spadix is probably one of negative feedback control. The feedback signals are based on the rate of temperature change of the spadix over time. A signal is factored into the Biochemical Energy generator, and becomes Biochemical Energy, some of which becomes heat. Comparing our proposed model temperature responses and those of the living spadix, we found good agreement. In the process of engineering the model, the existence of two regulatory pathways in the thermoregulation system was simulated, and our proposed model appears to provide the necessary elements to explain the fundamental mechanism of the thermoregulation system of S. foetidus.
Zhong Lin Wang - One of the best experts on this subject based on the ideXlab platform.
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self powered cardiovascular electronic devices and systems
Nature Reviews Cardiology, 2021Co-Authors: Qiang Zheng, Zhong Lin Wang, Qizhu TangAbstract:Cardiovascular electronic devices have enormous benefits for health and quality of life but the long-term operation of these implantable and wearable devices remains a huge challenge owing to the limited life of batteries, which increases the risk of device failure and causes uncertainty among patients. A possible approach to overcoming the challenge of limited battery life is to harvest Energy from the body and its ambient environment, including biomechanical, solar, thermal and Biochemical Energy, so that the devices can be self-powered. This strategy could allow the development of advanced features for cardiovascular electronic devices, such as extended life, miniaturization to improve comfort and conformability, and functions that integrate with real-time data transmission, mobile data processing and smart power utilization. In this Review, we present an update on self-powered cardiovascular implantable electronic devices and wearable active sensors. We summarize the existing self-powered technologies and their fundamental features. We then review the current applications of self-powered electronic devices in the cardiovascular field, which have two main goals. The first is to harvest Energy from the body as a sustainable power source for cardiovascular electronic devices, such as cardiac pacemakers. The second is to use self-powered devices with low power consumption and high performance as active sensors to monitor physiological signals (for example, for active endocardial monitoring). Finally, we present the current challenges and future perspectives for the field.
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hybrid nanogenerator for concurrently harvesting biomechanical and Biochemical Energy
ACS Nano, 2010Co-Authors: Benjamin Hansen, Ying Liu, Rusen Yang, Zhong Lin WangAbstract:Harvesting Energy from multiple sources available in our personal and daily environments is highly desirable, not only for powering personal electronics, but also for future implantable sensor-transmitter devices for biomedical and healthcare applications. Here we present a hybrid Energy scavenging device for potentialin vivoapplications. The hybrid device consists of a piezoelectric poly(vinylidenefluoride) nanofiber nanogeneratorforharvestingmechanicalEnergy,suchasfrombreathingorfromthebeatofaheart,andaflexible enzymatic biofuel cell for harvesting the Biochemical (glucose/O2) Energy in biofluid, which are two types of Energy availablein vivo. The two Energy harvesting approaches can work simultaneously or individually, thereby boostingoutputandlifetime.Usingthehybriddevice,wedemonstratea"self-powered"nanosystembypowering a ZnO nanowire UV light sensor.
Jules B. Van Lier - One of the best experts on this subject based on the ideXlab platform.
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direct and indirect effects of increased co2 partial pressure on the bioenergetics of syntrophic propionate and butyrate conversion
Environmental Science & Technology, 2020Co-Authors: Pamela Ceronchafla, Jules B. Van Lier, Robbert Kleerebezem, Korneel Rabaey, Ralph E F LindeboomAbstract:Simultaneous digestion and in situ biogas upgrading in high-pressure bioreactors will result in elevated CO2 partial pressure (pCO2). With the concomitant increase in dissolved CO2, microbial conversion processes may be affected beyond the impact of increased acidity. Elevated pCO2 was reported to affect the kinetics and thermodynamics of Biochemical conversions because CO2 is an intermediate and end-product of the digestion process and modifies the carbonate equilibrium. Our results showed that increasing pCO2 from 0.3 to 8 bar in lab-scale batch reactors decreased the maximum substrate utilization rate (rsmax) for both syntrophic propionate and butyrate oxidation. These kinetic limitations are linked to an increased overall Gibbs free Energy change (ΔGOverall) and a potential Biochemical Energy redistribution among syntrophic partners, which showed interdependence with hydrogen partial pressure (pH2). The bioenergetics analysis identified a moderate, direct impact of elevated pCO2 on propionate oxidation and a pH-mediated effect on butyrate oxidation. These constraints, combined with physiological limitations on growth exerted by increased acidity and inhibition due to higher concentrations of undissociated volatile fatty acids, help to explain the observed phenomena. Overall, this investigation sheds light on the role of elevated pCO2 in delicate Biochemical syntrophic conversions by connecting kinetic, bioenergetic, and physiological effects.
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Anaerobic stabilisation of urine diverting dehydrating toilet faeces (UDDT-F) in urban poor settlements : Biochemical Energy recovery
Journal of Water Sanitation and Hygiene for Development, 2019Co-Authors: Joy Riungu, Mariska Ronteltap, Jules B. Van LierAbstract:Biochemical Energy recovery using digestion and co-digestion of faecal matter collected from urine diverting dehydrating toilet faeces (UDDT-F) and mixed organic market waste (OMW) was studied under laboratory-and pilot-scale conditions. Laboratory-scale Biochemical methane potential (BMP) tests showed an increase in methane production with an increase in OMW fraction in the feed substrate. In subsequent pilot-scale experiments, one-stage and two-stage plug flow digester were researched, applying UDDT-F:OMW ratios of 4:1 and 1:0, at about 10 and 12% total solids (TS) slurry concentrations. Comparable methane production was observed in one-stage (Ro-4:1,12%) (314 ± 15 mL CH4/g VS added) and two-stage (Ram-4:1,12%) (325 ± 12 mL CH4 /g VS added) digesters, when applying 12% TS slurry concentration. However, biogas production in Ram-4:1,12% digester (571 ± 25 mL CH4/g VS added) was about 12% higher than in Ro-4:1,12%, significantly more than the slight difference in methane production, i.e. 3–4%. The former was attributed to enhanced waste solubilisation and increased CO2 dissolution, resulting from mixing the bicarbonate-rich methanogenic effluent for neutralisation purposes with the low pH (4.9) influent acquired from the pre-acidification stage. Moreover, higher process stability was observed in the first parts of the plug flow two-stage digester, characterised by lower VFA concentrations.