Dynamic Modeling of Tree Growth in a Nursery Greenhouse Using MATLAB and Simulink

2010 ◽  
Vol 121-122 ◽  
pp. 507-511
Author(s):  
Zi Dong Yang ◽  
Yu Bai
Keyword(s):  
Growth Rate ◽  
Seedling Growth ◽  
Process Model ◽  
Energy Use ◽  
Transfer Model ◽  
Test Case ◽  
Climate Control ◽  
Unit Energy ◽  
Set Up ◽  
The Impact

The GUESS (Greenhouse Use of Energy Seedling Simulator) model is a lumped-parameter coupled dynamic simulation combining a carbon-based process model of seedling growth with a heat/mass transfer model of the greenhouse envelope. GUESS was created to provide nursery managers and engineers a tool to assess the impact of climate control decisions upon energy use and seedling growth rate. The source code for GUESS was written using Simulink and MATLAB. A test case was set up to validate the model. And experimented with different lighting targets to see which one offered the most growth per unit energy cost. The model was parameterized for Douglas fir production in Corvallis, OR Seedlings were started at 0.57g d.w and were harvested at 1.7g d.w Temperature regulated to 68.5±6.3°F Growth rate could be highly sensitive to carbon content conversion as well.Models can be very useful as simulation tools, but their utility depends highly upon the data used to parameterize them.

The Impact of COVID-19 on Energy Consumption in the United States: An Overview

2021 ◽  
Author(s):  
Lindsey Kahn ◽  
Hamidreza Najafi
Keyword(s):  
Growth Rate ◽  
Energy Consumption ◽  
Energy Use ◽  
The United States ◽  
Average Annual Growth Rate ◽  
Annual Growth ◽  
Annual Growth Rate ◽  
End User ◽  
End Use ◽  
The Impact

Abstract Lockdown measures and mobility restrictions implemented to combat the spread of the novel COVID-19 virus have impacted energy consumption patterns, particularly in the United States. A review of available data and literature on the impact of the pandemic on energy consumption is performed to understand the current knowledge on this topic. The overall decline of energy use during lockdown restrictions can best be identified through the analysis of energy consumption by source and end-user breakdown. Using monthly energy consumption data, the total 9-months use between January and September for the years 2015–2020 are calculated for each end-use. The cumulative consumption within these 9 months of the petroleum, natural gas, biomass, and electricity energy by the various end-use sectors are compared to identify a shift in use throughout time with the calculation of the percent change from 2019 to 2020. The analysis shows that the transportation sector experienced the most dramatic decline, having a subsequent impact on the primary energy it uses. A steep decline in the use of petroleum and natural gas by the transportation sector has had an inevitable impact on the emission of carbon dioxide and other air pollutants during the pandemic. Additionally, the most current data for the consumption of electricity by each state and each end-user in the times before and during the pandemic highlights the impact of specific lockdown procedures on energy use. The average total consumption for each state was found for the years 2015–2019. This result is used calculation of yearly growth rate and average annual growth rate in 2020 for each state and end-user. The total average annual growth rate for 2020 was used to find a correlation coefficient between COVID-19 case and death rates as well as population density and lockdown duration. To further examine the relationship a correlation coefficient was calculated between the 2020 average annual growth rate for all sectors and average annual growth rate for each individual end-user.

Physiological trade-offs associated with methyl jasmonate - induced resistance in Pinus radiata

2008 ◽  
Vol 38 (4) ◽  
pp. 677-684 ◽  
Author(s):  
Nick Gould ◽  
Tony Reglinski ◽  
Mike Spiers ◽  
Joe T. Taylor
Keyword(s):  
Growth Rate ◽  
Disease Resistance ◽  
Methyl Jasmonate ◽  
Water Potential ◽  
Seedling Growth ◽  
Pinus Radiata ◽  
Transpiration Rate ◽  
Meja Treatment ◽  
Seedling Growth Rate ◽  
The Impact

Methyl jasmonate (MeJA) can induce defence responses in plants to pathogen attack, but it can also have consequences for plant growth. The transient effects of exogenous MeJA treatment on the resistance of Monterey pine ( Pinus radiata D. Don) seedlings to Diplodia pinea (Desm.) Kickx. and some physiological parameters affecting the impact of treatment on seedling growth were investigated. Following foliar application of 4.5 mmol·L–1 MeJA, disease resistance was greatest 1–2 weeks after treatment and declined with time thereafter. Elevated disease resistance was accompanied by a reduction in seedling growth rate the second week following MeJA treatment. Thereafter, seedling growth rate recovered and exceeded that of the control seedlings 4–5 weeks after MeJA treatment. Within hours of MeJA treatment, reductions in both the capacity of photosystem II and transpiration rate were observed, resulting in a concomitant reduction in net CO2 uptake rate. The slight reduction in transpiration rate was also associated with an increase in needle water potential. Longer term measurements showed no effect of MeJA on photosynthetic rate, transpiration rate, chlorophyll content, or shoot water potential and thus could not account for the elevated growth rate observed 4–5 weeks after treatment.

scholarly journals THE IMPACT OF HUMAN FACTORS ON THE CHANGE IN VEGETATION COVER OF THE BE RIVER BASIN IN THE PERIOD FROM 2000 TO 2015

2020 ◽  
Vol 15 (9) ◽  
pp. 53
Author(s):  
Phan Văn Trung ◽  
Nguyễn Thám
Keyword(s):  
Growth Rate ◽  
Human Factors ◽  
Population Growth ◽  
River Basin ◽  
Vegetation Cover ◽  
Population Growth Rate ◽  
Mapping Method ◽  
Rapid Urbanization ◽  
Set Up ◽  
The Impact

 The Be river basin is located in the area with a rapid urbanization rate and a large immigrants proportion annually. Therefore, the population growth rate for the period from 2000 to 2015 in the river basin is up 3,53% which is 3,27 times as high as the population growth rate of Vietnam. These are the major causes leading to the fluctuation in vegetation cover of the Be river basin during over time. This research used methodologies including data collection, statistical analysis, mapping method and geographic information system to evaluate the impact of human factors to the vegetation cover fluctuation of the Be river basin in the period from 2000 to 2015. Based on the results of change map in the vegetation cover, a research group set up fluctuating matrix, analyze to clarify the vegetation coverfluctuation situation due to human’s impacts in the Be river basin in the period from 2000 to 2015. 

A Control-Oriented Modeling Approach to Spatial Neutronics Simulation of a Lead-Cooled Fast Reactor

2015 ◽  
Vol 1 (3) ◽  
Author(s):  
S. Lorenzi ◽  
A. Cammi ◽  
L. Luzzi ◽  
R. Ponciroli
Keyword(s):  
Differential Equations ◽  
Fast Reactor ◽  
Control Strategies ◽  
Object Oriented ◽  
Time Dependent ◽  
Transfer Model ◽  
Test Case ◽  
Modeling Approach ◽  
Fuel Pin ◽  
Set Up

The most diffused neutronics modeling approach in control-oriented simulators is pointwise kinetics. In the framework of developing control strategies for innovative reactor concepts, such a simplified description is less effective as it prevents the possibility of exploiting the capabilities of advanced control schemes. In the present work, in order to overcome these limitations, a spatial neutronics description based on the modal method has been considered. This method allows separating the spatial and time dependence of the neutron flux, which can be represented as the sum of the eigenfunctions of the neutron diffusion equation weighted by time-dependent coefficients. In this way, the system dynamic behavior is reduced to the study of these coefficients and can be represented by a set of ordinary differential equations (ODEs), reducing the simulation computational burden. In this paper, a test case involving three fuel pins of an innovative lead-cooled fast reactor has been set up and investigated. Once the eigenfunctions are obtained, the set of ODEs for studying the time-dependent coefficients has been derived and then implemented in the DYMOLA environment, developing an object-oriented component based on the reliable, tested, and well-documented Modelica language. In addition, a heat transfer model for the fuel pin has been developed, still drawing on the principles of the object-oriented modeling. Finally, in order to assess the performance of the developed spatial neutronics component, the outcomes have been compared with the reference results obtained from the multigroup diffusion partial differential equations, achieving a satisfactory agreement.

The impact of sea-glint upon limb radiance

2007 ◽  
Vol 85 (11) ◽  
pp. 1159-1176
Author(s):  
D A Degenstein ◽  
A E Bourassa ◽  
E J Llewellyn ◽  
N D Lloyd
Keyword(s):  
Radiative Transfer ◽  
Zenith Angle ◽  
Arabian Sea ◽  
Solar Zenith Angle ◽  
Imaging System ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Test Case ◽  
Infra Red ◽  
The Impact

A simple radiative transfer model is developed to calculate the contribution of sea-glint to limb radiance. It is shown that the absolute sea-glint signal peaks between 70° and 80° solar zenith angle. Sea-glint can contribute 10–15% of the total limb radiance at wavelengths greater than 600 nm, which is several times brighter than an equivalent 5% reflecting Lambertian ocean surface. A test case was identified over the Arabian Sea in October 2002 and the model results compared to limb observations from the Optical Spectrograph and Infra-Red Imaging System (OSIRIS) on-board the Odin satellite. PACS Nos.: 94.10.Gb, 93.85.+q, 42.68.Ay, 42.68.Mj

scholarly journals Identifying reliable fitness proxies for growing animals responding to anthropogenic changes

2020 ◽  
Author(s):  
Andrew D. Higginson
Keyword(s):  
Growth Rate ◽  
Mortality Rate ◽  
Predation Risk ◽  
Energy Use ◽  
Metabolic Costs ◽  
Theoretical Predictions ◽  
Increasing Temperature ◽  
The Impact ◽  
The Relationship ◽  
Increase Mortality Rate

ABSTRACTAnthropogenic influences on habitats often affect predation on species by introducing novel predators, supporting additional predators, or reducing animals’ ability to detect or avoid predators. Other changes may reduce the ability of animals to feed, or alter their energy use. An increase in predation risk is assumed to reduce prey populations by increasing mortality, reducing foraging and growth. Often animals don’t appear to have been adversely affected, or may even increase growth rate. However, theoretical predictions that may have been overlooked suggest that optimal foraging rate, mortality rate and growth rate may change in counter-intuitive ways, depending on exactly how predation risk or costs have been increased. Increasing predator density may increase mortality rate when foraging, reduce the safety of refuges, or alter the relationship between vigilance and attack likelihood. Increasing temperature may increase metabolic costs in ectotherms and reduce thermogenesis costs in endotherms, which affects the costs of active foraging and inactivity differently. Here, I review the theory on how predation risk and metabolic costs should affect foraging behaviour, mortality and growth in order to explain the great variation in behavioural responses. I show that in some situations animals may not respond behaviourally even though a change severely affects survival, and the mortality may be a poor metric of the impact of a change on population viability. In other situations a fitness proxy may change dramatically whilst fitness is unaffected due to compensatory changes in behaviour or life history. Other measures may change in a positive way whilst fitness declines. I describe how to identify the situations in the field and thereby make reliable measure of fitness in particular study systems. Overall, this work shows how behavioural theory can help understand the impacts of environmental change and highlights promising directions to better understand and mitigate their effects on ecosystems.

scholarly journals The Impact and Successes of a Paediatric Endocrinology Fellowship Program in Africa

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Gordon Otieno Odundo ◽  
Thomas Ngwiri ◽  
Olivia Otuoma ◽  
Paul Laigong ◽  
Renson Mukhwana ◽  
...  
Keyword(s):  
Phase I ◽  
Phase Ii ◽  
Access To Health Care ◽  
Transfer Model ◽  
Endocrine Disorders ◽  
African Countries ◽  
Centers Of Excellence ◽  
Paediatric Endocrinology ◽  
Set Up ◽  
The Impact

Background.The prevalence and distribution of endocrine disorders in children in Africa are not well known because most cases are often undiagnosed or diagnosed too late. The awareness of this led to the launch of the Paediatric Endocrinology Training Center for Africa (PETCA) designed to improve quality and access to health care by training paediatricians from Africa in paediatric endocrinology.Methods.The fellowship is undertaken over an 18-month period: six months of clinical and theoretical training in Kenya, nine months of project research at the fellow’s home country, and three months of consolidation in Kenya. Upon completion, certified paediatricians are expected to set up centers of excellence.Results.There have been two phases, phase I from January 2008 to October 2012 and phase II from January 2012 to April 2015. Fifty-four fellows from 12 African countries have been certified, 34 (phase I) and 20 (phase II). Over 1,000 patients with wide ranging diabetes and endocrine disorders have been diagnosed and treated and are being followed up at the centers of excellence.Conclusion.The successes of the PETCA initiative demonstrate the impact a capacity building and knowledge transfer model can have on people in resource-poor settings using limited resources.

International trade: Research of the reasons for the fall

2019 ◽  
pp. 79-91 ◽  
Author(s):  
V. S. Nazarov ◽  
S. S. Lazaryan ◽  
I. V. Nikonov ◽  
A. I. Votinov
Keyword(s):  
Growth Rate ◽  
International Trade ◽  
Exchange Rate ◽  
Global Economy ◽  
Structural Changes ◽  
Global Value Chains ◽  
Value Chains ◽  
Negative Contribution ◽  
Basic Commodity ◽  
The Impact

The article assesses the impact of various factors on the growth rate of international trade. Many experts interpreted the cross-border flows of goods decline against the backdrop of a growing global economy as an alarming sign that indicates a slowdown in the processes of globalization. To determine the reasons for the dynamics of international trade, the decompositions of its growth rate were carried out and allowed to single out the effect of the dollar exchange rate, the commodities prices and global value chains on the change in the volume of trade. As a result, it was discovered that the most part of the dynamics of international trade is due to fluctuations in the exchange rate of the dollar and prices for basic commodity groups. The negative contribution of trade within global value chains in 2014 was also revealed. During the investigated period (2000—2014), such a picture was observed only in the crisis periods, which may indicate the beginning of structural changes in the world trade.

The Emergence of Rabbinic Culture from the Perspective of Qumran

2015 ◽  
Vol 6 (2) ◽  
pp. 253-274
Author(s):  
Vered Noam
Keyword(s):  
Early Stage ◽  
Second Temple ◽  
Test Case ◽  
Literary Works ◽  
Jewish Culture ◽  
The Bible ◽  
Set Up

The rabbinic halakhic system, with its many facets and the literary works that comprise it, reflects a new Jewish culture, almost completely distinct in its halakhic content and scope from the biblical and postbiblical culture that preceded it. By examining Jewish legislation in the area of corpse impurity as a test case, the article studies the implications of Qumranic halakhah, as a way-station between the Bible and the Mishnah, for understanding how Tannaitic halakhah developed. The impression obtained from the material reviewed in the article is that the direction of the “Tannaitic revolution” was charted, its methods set up, and its principles established, at a surprisingly early stage, before the destruction of the Second Temple, and thus at the same time that the Qumran literature was created.

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