scholarly journals Harpacticoid copepod response to epiphyte load variations inPosidonia oceanica(L.) Delile meadows

2013 ◽  
Vol 34 (3) ◽  
pp. 345-362 ◽  
Author(s):  
Nina Larissa Arroyo ◽  
Inés Castejón ◽  
Marta Dominguez ◽  
Jorge Terrados
Keyword(s):  
Harpacticoid Copepod ◽  
Load Variations ◽  
Epiphyte Load

scholarly journals Robust Tracker of Hybrid Microgrids by the Invariant-Ellipsoid Set

Electronics ◽  
2021 ◽  
Vol 10 (15) ◽  
pp. 1794
Author(s):  
Hilmy Awad ◽  
Ehab H. E. Bayoumi ◽  
Hisham M. Soliman ◽  
Michele De Santis
Keyword(s):  
Sliding Mode ◽  
Tracking Error ◽  
Nonlinear Dynamical System ◽  
Sufficient Conditions ◽  
Linear Matrix ◽  
Nonlinear Dynamical ◽  
Load Variations ◽  
Invariant Ellipsoid ◽  
Steady State Responses ◽  
Linearized Model

This paper introduces a new ellipsoidal-based tracker design to control a grid-connected hybrid direct current/alternating current (DC/AC) microgrid (MG). The proposed controller is robust against both parameters and load variations. The studied hybrid MG is modelled as a nonlinear dynamical system. A linearized model around an operating point is developed. The parameter changes are modelled as norm-bounded uncertainties. We apply the new extended version of the attractive (or invariant) ellipsoid for this tracking problem. Convex optimization is used to obtain the region’s minimal size where the tracking error between the state trajectories and the reference states converges. The sufficient conditions for stability are derived and solved based on linear matrix inequalities (LMIs). The proposed controller’s validity is shown via simulating the hybrid MG with various operational scenarios. In each scenario, the performance of the controller is compared with a recently proposed sliding mode controller. The comparison clearly illustrates the superiority of the developed controller in terms of transient and steady-state responses.

Characterizing population structure of coral-associated fauna from mesophotic and shallow habitats in the Caribbean

2018 ◽  
Vol 99 (3) ◽  
pp. 619-629 ◽  
Author(s):  
Alex J. Veglia ◽  
Nicholas M. Hammerman ◽  
Carlos R. Rivera Rosaly ◽  
Matthew Q. Lucas ◽  
Alexandra Galindo Estronza ◽  
...  
Keyword(s):  
Population Structure ◽  
Puerto Rico ◽  
Marine Invertebrates ◽  
Geographic Distance ◽  
Harpacticoid Copepod ◽  
Coi Gene ◽  
Mitochondrial Coi ◽  
Symbiotic Relationships ◽  
Harpacticoid Copepods ◽  
Obligate Symbiont

Symbiotic relationships are a common phenomenon among marine invertebrates, forming both obligatory and facultative dependencies with their host. Here, we investigate and compare the population structure of two crustacean species associated with both shallow and mesophotic ecosystems: an obligate symbiont barnacle (Ceratoconcha domingensis), of the coral Agaricia lamarcki and a meiobenthic, free-living harpacticoid copepod (Laophontella armata). Molecular analyses of the Cytochrome Oxidase Subunit I (COI) gene revealed no population structure between mesophotic and shallow barnacle populations within south-west Puerto Rico (ΦST = 0.0079, P = 0.33). The absence of population structure was expected due to the pelagic naupliar larvae of the barnacles and the connectivity patterns exhibited by the coral itself within the same region. Laophontella armata exhibited significant structure based on the mitochondrial COI gene between the mesophotic reef ecosystem of El Seco, Puerto Rico and mangrove sediments of Curaçao (ΦST = 0.2804, P = 0.0). The El Seco and Curaçao copepods shared three COI haplotypes despite the obligatory benthic development of harpacticoid copepods and the geographic distance between the two locations. Three other COI haplotypes from El Seco exhibited higher than expected (up to 7%) intra-species variability, potentially representing three new cryptic species of harpacticoid copepods or rare, deeply divergent lineages of L. armata. This result is evidence for the urgent need of a deeper investigation into the meiofauna diversity associated with mesophotic coral ecosystems (MCEs), arguably the most diverse metazoan component of MCEs.

Influence of the Insecticide Diflubenzuron (Dimilin) on the Growth of Marine Diatoms and a Harpacticoid Copepod in Culture

1985 ◽  
Vol 42 (7) ◽  
pp. 1272-1277 ◽  
Author(s):  
N. J. Antia ◽  
P. J. Harrison ◽  
D. S. Sullivan ◽  
T. Bisalputra
Keyword(s):  
Skeletonema Costatum ◽  
Harpacticoid Copepod ◽  
Adult Survival ◽  
Thalassiosira Weissflogii ◽  
Marine Diatoms ◽  
Tigriopus Californicus ◽  
Per Se ◽  
Juvenile Development ◽  
Cyclotella Cryptica ◽  
Injurious Effects

Diflubenzuron (Dimilin) was tested, in the concentration range 0.1–5000 μg∙L−1, for possible injurious effects on the growth and photosynthesis of three chitin-producing (Thalassiosira weissflogii, T. norden-skioldii, Cyclotella cryptica) and one nonchitinaceous (Skeletonema costatum) diatoms. For comparison, the effects of the pesticide were also examined on adult survival and juvenile development of the harpacticoid copepod Tigriopus californicus. While the development of the copepod was hindered at concentrations of the order of 1–10 μg∙L−1, the diatoms were barely affected by Dimilin even at the highest concentration tested (5 mg∙L−1). We conclude that Dimilin acts specifically on insects and crustaceans as a larvicide by interfering with chitin deposition into cuticles during juvenile development through ecdysis. The lack of effect from Dimilin on the chitin-producing diatoms has suggested that the insecticide may not inhibit chitin biosynthesis per se as was previously believed, but that it presumably deregulates one or more of the larval postsynthetic processes responsible for chitin integration into cuticles.

Optimization of a Wireless Power Transfer System With a Repeater Against Load Variations

2017 ◽  
Vol 64 (10) ◽  
pp. 7800-7809 ◽  
Author(s):  
Prasad Kumara Sampath Jayathurathnage ◽  
Arokiaswami Alphones ◽  
D. Mahinda Vilathgamuwa
Keyword(s):  
Wireless Power Transfer ◽  
Transfer System ◽  
Power Transfer ◽  
Wireless Power ◽  
Load Variations ◽  
Wireless Power Transfer System

scholarly journals Nonlinear Control of a Satellite Electrical Power System Based on the Sliding Mode Control

2013 ◽  
Vol 2013 ◽  
pp. 1-8
Author(s):  
Mohammad Rasool Mojallizadeh ◽  
Bahram Karimi
Keyword(s):  
Power System ◽  
Sliding Mode ◽  
Electrical Power ◽  
Voltage Regulation ◽  
Sliding Mode Controller ◽  
Electrical Power System ◽  
Load Variations ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Power Point

The power electronic interface between a satellite electrical power system (EPS) with a photovoltaic main source and battery storage as the secondary power source is modelled based on the state space averaging method. Subsequently, sliding mode controller is designed for maximum power point tracking of the PV array and load voltage regulation. Asymptotic stability is ensured as well. Simulation of the EPS is accomplished using MATLAB. The results show that the outputs of the EPS have good tracking response, low overshoot, short settling time, and zero steady-state error. The proposed controller is robust to environment changes and load variations. Afterwards, passivity based controller is provided to compare the results with those of sliding mode controller responses. This comparison demonstrates that the proposed system has better transient response, and unlike passivity based controller, the proposed controller does not require reference PV current for control law synthesis.

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