scholarly journals Simulating the effects of temperature on individual and population growth of Rhinoptera bonasus: a coupled bioenergetics and matrix modeling approach

2007 ◽  
Vol 329 ◽  
pp. 211-223 ◽  
Author(s):  
JA Neer ◽  
KA Rose ◽  
E Cortés
Keyword(s):  
Population Growth ◽  
Modeling Approach ◽  
Rhinoptera Bonasus ◽  
Matrix Modeling ◽  
Effects Of Temperature

scholarly journals Complementary Configuration and Optimal Energy Flow of CCHP-ORC Systems Using a Matrix Modeling Approach

Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Wencong Huang ◽  
Yufang Chang ◽  
Youxin Yuan
Keyword(s):  
Energy Conversion ◽  
Thermal Energy ◽  
Energy Flow ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Optimal Operation ◽  
Modeling Approach ◽  
Matrix Modeling ◽  
Study Results ◽  
System Components

A mass of thermal energy from the combined cooling, heating, and power (CCHP) system will be wasted by the buildings with low ratio of heat to power demand. To further improve the using efficiency of the excess thermal energy, an active method, which adds the organic Rankine cycle (ORC) equipment in the CCHP system, is configured. A complementary configuration of this CCHP-ORC is also investigated. This paper presents a matrix modeling approach to establish a mathematical model of the CCHP-ORC system. The CCHP-ORC system can be viewed as a multiple input and multiple output (MIMO) model. Energy conversion of the system components is described as the efficiency matrices. Energy flow between the system components is described as dispatch matrices. Energy conversion and flow from the system input to output are modeled by a conversion matrix. The objective function and the constraints of the system are determined. The optimal operation strategies are obtained by solving the optimization problem of minimizing the evaluation criteria function. Comprehensive case studies are conducted based on a hypothetical CCHP-ORC system. The study results reveal that the effectiveness and economic efficiency of the proposed approaches outperform those obtained from conventional CCHP systems.

scholarly journals Quantifying the influence of salinity and temperature on the population dynamics of a marine ectoparasite

2016 ◽  
Vol 73 (8) ◽  
pp. 1281-1291 ◽  
Author(s):  
Maya L. Groner ◽  
Gregor F. McEwan ◽  
Erin E. Rees ◽  
George Gettinby ◽  
Crawford W. Revie
Keyword(s):  
Population Dynamics ◽  
Low Temperature ◽  
Population Growth ◽  
Low Temperatures ◽  
Sea Lice ◽  
Life Stages ◽  
Low Salinity ◽  
Linear Effects ◽  
Effects Of Temperature ◽  
Substantial Morbidity

Sea lice are common ectoparasites of farmed and wild salmonids and can cause substantial morbidity and mortality in their hosts. While sea lice infections are common in estuarine areas with variable salinity, the effects of salinity on population dynamics are poorly understood. We used existing literature to parameterize salinity-dependent logistic mortality curves for different life stages of sea lice. We then used population matrix models to characterize the effects of temperature and salinity on sea louse population growth. Our models showed that low salinity decreases survival, while low temperature retards sea louse development. In contrast with the linear effects of temperature on sea louse development, salinity has a nonlinear effect on sea louse survival; values below 20 psu cause mortality, while values above 20 psu have little effect on survival. Simulations showed that sea louse population growth can be greatest in zones that are intermediate between estuarine and oceanic. In these cases population growth is not limited by the low salinities found in more estuarine sites or the low temperatures found in more oceanic sites.

scholarly journals Six-Year Demographic Study of the Terrestrial Orchid, Crepidium acuminatum: Implications for Conservation

2021 ◽  
Vol 9 ◽  
Author(s):  
Binu Timsina ◽  
Pavel Kindlmann ◽  
Zuzana Münzbergová ◽  
Maan B. Rokaya
Keyword(s):  
Population Dynamics ◽  
Population Growth ◽  
Management Strategies ◽  
Natural Populations ◽  
Important Species ◽  
Growth And Survival ◽  
Population Growth Rates ◽  
Matrix Modeling ◽  
Species Population ◽  
Medicinal Orchid

Studies on population dynamics are helpful for understanding the factors determining population development and predicting the effects of disturbances, such as harvesting of plant species. In an investigation of the demography of a terrestrial medicinal orchid known as Crepidium acuminatum, the effects of harvesting on its population dynamics were recorded. Data on recruitment, growth and survival were collected in three populations of C. acuminatum over a 6-year period (2012–2017) in central Nepal. A matrix modeling method was used to determine the effect of different harvesting regimes on the population growth and survival of this species. Population growth rates (λ) of unharvested populations were relatively similar and stable in different years of the study. Harvesting significantly reduced λ. The results of this study indicate that the sustainable survival of a population that is subject to harvesting can only occur when it is either selective (only flowering individuals or only small amounts of vegetative individuals) or rotational (once every 3–5 or more years). This study demonstrates the necessity of using a sustainable method when harvesting natural populations. Our results are useful for developing efficient management strategies for this species. As each species has a different biology, similar studies are needed for other rare and/or economically important species in the Himalayan region and in other understudied parts of the world.

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