- B.M. Nicolai (1)
- M.A. Retta (1)
- R. Shamshiri (1)
- R.G.M. Sman Van Der (1)
- P.C. Struik (1)
- P. Verboven (1)
- W.I. Wan Ismail (1)
- Xinyou Yin (1)
- A.J. Zakaria (1)
Digital growth response maps for assessment of cooling requirement in greenhouse production of tomato
Shamshiri, R. ; Che Man, H. ; Zakaria, A.J. ; Beveren, Peter van; Wan Ismail, W.I. ; Ahmad, D. - \ 2017
Acta Horticulturae 1152 (2017). - ISSN 0567-7572 - p. 117 - 124.
Computer simulation - Cooling requirement - Greenhouse - Growth response map - Temperature - Tomato - Tropical lowland
The objective of this work was to generate a series of digital growth response maps that address specific times of cooling requirement for tomato production in a tropical lowland greenhouse. Collected data from a net-screen covered greenhouse were processed by a computer model that utilized a mathematical approach to simulate tomato's growth responses (GR) to air temperature at early growth and development growth stages. Orthogonal projection was applied on three-dimensional GR plots to create top-view sketch to demonstrate variations with respect to changes in hours and days. Results indicated that air temperature inside the greenhouse was 65% optimal at the early growth stage and 72% optimal at the development growth stage of tomato.
Exploring anatomical controls of C4 leaf photosynthesis using a 3D reaction-diffusion model
Retta, M.A. ; Ho, Q.T. ; Yin, Xinyou ; Verboven, P. ; Berghuijs, H.N.C. ; Struik, P.C. ; Nicolai, B.M. - \ 2017
Acta Horticulturae 1154 (2017). - ISSN 0567-7572 - p. 171 - 177.
Biophysical model - CO concentration mechanism gas exchange - Computer simulation - Leaf microstructure
C4 plants such as maize (Zea mays L.), sugarcane (Saccharum officinarum L.) and sorghum [Sorghum bicolor (L.) Moench.] photosynthesize at a high rate due to a CO2 concentration mechanism (CCM) that accumulates CO2 to saturating concentrations around the carboxylation site of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). Transport of CO2 inside a leaf and, therefore, the CCM, is affected by leaf microstructure. Gas transport models with a realistic leaf microstructure help to assess the significance of anatomical features of C4 plants quantitatively for effective CCM. One- and two-dimensional gas transport models, when applied to analyze the gas diffusion in leaves, understate the three-dimensional nature. Here, we present the first 3D reaction-diffusion model for photosynthesis of a C4 leaf. Equations of CO2 transport and bicarbonate diffusion combined with a biochemical model of C4 photosynthesis were discretized over the 3D geometry of a maize leaf tissue. The model could describe the trends in responses of photosynthesis to light and CO2. The CO2 profile in the leaf microstructure was highly heterogeneous. The model suggests that rapid diffusion of CO2 to mesophyll cytosol is essential to achieve a high rate of photosynthesis.
Phase field simulations of ice crystal growth in sugar solutions
Sman, R.G.M. Van Der - \ 2016
International Journal of Heat and Mass Transfer 95 (2016). - ISSN 0017-9310 - p. 153 - 161.
Computer simulation - Ice crystal growth - Phase field method - Sugar solution
We present the first model ever, that describes explicitly ice crystal growth in a sugar solution during freezing. This 2-D model uses the phase field method, supplemented with realistic, and predictive theories on the thermodynamics and (diffusion) kinetics of this food system. We have to make use of a novel type of phase field to obtain realistic, micron-sized ice crystals, and exclusion of sugar from the crystalline phase. Via simulation of a single ice crystal, we identify important time scales governing the growth. These times scales are also important for the coarsening of the ice morphology in freezing systems with multiple ice crystals. These simulations show that the average ice crystal size is governed by the freezing rate via a power law, similar to an empirical relation from literatures, which is deduced from experiment. The presented model is viewed as a good basis for even more realistic simulations of crystal growth in food.