Effects of internal conductance and Rubisco on the optimum temperature for leaf photosynthesis in Fallopia japonica growing at different altitudes

Marked vertical variations of ions and oxygen isotopes were present in the snowpack at the glacier Austre Okstindbreen during the pre-melting phase in 1995 at sites between 825 m and 1,470 m above sea level. As the first meltwater percolated from the top of the pack, ions were moved to a greater depth, but the isotopic composition remained relatively unchanged. Ions continued to move downwards through the pack during the melting phase, even when there was little surface melting and no addition of liquid precipitation. The at-a-depth correlation between ionic concentrations and isotopic ratios, strong in the pre-melting phase, weakened during melting. In August, concentrations of Na+ and Mg2+ ions in the residual pack were low and vertical variations were slight; 18O enrichment had occurred. The difference of the time at which melting of the snowpack starts at different altitudes influences the input of ions and isotopes to the underlying glacier.

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Scaling leaf photosynthesis to canopy in a mixed deciduous forest. I. model description

Silva Gandavensis ◽

10.21825/sg.v62i0.842 ◽

1997 ◽

Vol 62 ◽

Author(s):

R. Samson ◽

S. Follens ◽

R. Lemeur

Keyword(s):

Temperature Dependence ◽

Quercus Robur ◽

Deciduous Forest ◽

Growing Season ◽

Model Description ◽

Canopy Photosynthesis ◽

Leaf Photosynthesis ◽

Layer Model ◽

Mixed Deciduous Forest ◽

Leaf Level

A multi-layer model (FORUG) was developed, to simulate the canopy photosynthesis of a mixed deciduous forest during the growing season. Measured photosynthesis parameters, for beech (Fagus sylvatica), oak (Quercus robur) and ash (Fraxinus excelsior), were used as input to the model. This information at the leaf level is then scaled up to the level of the canopy, taking into account the radiation profiles (diffuse and direct PAR) in the canopy, the vertical LAI distribution, the evolution of the LAI and the photosynthesis parameters during the growing season, and the temperature dependence of the latter parameters.

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Joint analysis of the magnetic field and Total Gradient Intensity in Central Europe

10.5194/se-2019-40 ◽

2019 ◽

Author(s):

Maurizio Milano ◽

Maurizio Fedi ◽

J. Derek Fairhead

Keyword(s):

Magnetic Field ◽

Central Europe ◽

Joint Analysis ◽

East European ◽

Long Wavelength ◽

Low Degree ◽

Total Gradient ◽

Synthetic Models ◽

The Magnetic Field ◽

Different Altitudes

Abstract. In the European region, the magnetic field at satellite altitudes (~ 350 km) is mainly defined by a long-wavelength magnetic-low called here the Central Europe Magnetic Low (CEML), located to the southwest of the Trans European Suture Zone (TESZ). We studied this area by a joint analysis of the magnetic and total gradient (∇T) anomaly maps, for a range of different altitudes of 5 km, 100 km and 350 km. Tests on synthetic models showed the usefulness of the joint analysis at various altitudes to identify reverse dipolar anomalies and to characterize areas in which magnetization is weak. By this way we identified areas where either reversely or normally magnetized sources are locally dominant. At a European scale these anomalies are sparse, with a low degree of coalescence effect. The ∇T map indeed presents generally small values within the CEML area, indicating that the Palaeozoic Platform is weakly magnetized. At 350 km altitude, the TESZ effect is largely dominant: with intense ∇T highs above the East European Craton (EEC) and very small values above the Palaeozoic Platform, this again denoting a weakly magnetized crust. Small coalescence effects are masked by the trend of the TESZ. Although we identified sparsely located reversely magnetized sources in the Palaeozoic Platform of the CEML, the joint analysis does not support a model of a generally reversely magnetized crust. Instead, our analysis strongly favors the hypothesis that the CEML anomaly is mainly caused by a sharp contrast between the magnetic properties of EEC and Palaeozoic Platform.

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Bio-Oil Characterizations of Spirulina Platensis Residue (SPR) Pyrolysis Products for Renewable Energy Development

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.849.47 ◽

2020 ◽

Vol 849 ◽

pp. 47-52

Author(s):

Siti Jamilatun ◽

Aster Rahayu ◽

Yano Surya Pradana ◽

Budhijanto ◽

Rochmadi ◽

...

Keyword(s):

Renewable Energy ◽

Spirulina Platensis ◽

Pyrolysis Temperature ◽

Renewable Energy Sources ◽

Fixed Bed ◽

Fixed Bed Reactor ◽

Oil Yield ◽

Optimum Temperature ◽

Pyrolysis Products ◽

Bio Oil

Nowadays, energy consumption has increased as a population increases with socio-economic developments and improved living standards. Therefore, it is necessary to find a replacement for fossil energy with renewable energy sources, and the potential to develop is biofuels. Bio-oil, water phase, gas, and char products will be produced by utilizing Spirulina platensis (SPR) microalgae extraction residue as pyrolysis raw material. The purpose of this study is to characterize pyrolysis products and bio-oil analysis with GC-MS. Quality fuel is good if O/C is low, H/C is high, HHV is high, and oxygenate compounds are low, but aliphatic and aromatic are high. Pyrolysis was carried out at a temperature of 300-600°C with a feed of 50 grams in atmospheric conditions with a heating rate of 5-35°C/min, the equipment used was a fixed-bed reactor. The higher the pyrolysis temperature, the higher the bio-oil yield will be to an optimum temperature, then lower. The optimum temperature of pyrolysis is 550°C with a bio-oil yield of 23.99 wt%. The higher the pyrolysis temperature, the higher the H/C, the lower O/C. The optimum condition was reached at a temperature of 500°C with the values of H/C, and O/C is 1.17 and 0.47. With an increase in temperature of 300-600°C, HHV increased from 11.64 MJ/kg to 20.63 MJ/kg, the oxygenate compound decreased from 85.26 to 37.55 wt%. Aliphatics and aromatics increased, respectively, from 5.76 to 36.72 wt% and 1.67 to 6.67 wt%.

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