scholarly journals Performance analysis of two-stage pressure retarded osmosis

2021 ◽  
Vol 302 ◽  
pp. 01012
Author(s):  
Suksun Amornraksa ◽  
Kanokporn Youyen ◽  
Lida Simasatitkul
Keyword(s):  
Power Generation ◽  
Power Density ◽  
Strong Influence ◽  
Average Power ◽  
The Other ◽  
Hydraulic Pressure ◽  
Flow Ratio ◽  
Two Stage ◽  
Pressure Retarded Osmosis ◽  
Total Membrane

The performance of a two-stage pressure retarded osmosis (PRO) for power generation with a total membrane length of 1 meter was investigated and analyzed in this work. Two feed configurations of freshwater and seawater were studied: one with the freshwater entering at the first stage only and the other with freshwater entering at both stages. The effect of membrane length and flow ratio between freshwater and seawater on the PRO performance were also examined. The results revealed that the performances of both feed configurations were quite similar. The membrane with a shorter length offered a higher average power density than that of a longer length. It was also revealed that the flow ratio had a strong influence on the average power density produced. The maximum average power density of 10.15 W/m2 was obtained at the applied hydraulic pressure of 12 bar, the flow ratio of 5, and the membrane length of both stages of 0.5 meter. The best water utilization was achieved at 65%.

Impulsivity and Aggression: A Meta-analysis Using the UPPS Model of Impulsivity

2019 ◽  
Author(s):  
Konrad Bresin
Keyword(s):  
Structural Equation Modeling ◽  
Sensation Seeking ◽  
Structural Equation ◽  
Meta Analysis ◽  
The Other ◽  
Equation Modeling ◽  
Negative Urgency ◽  
Two Stage ◽  
Trait Impulsivity

Trait impulsivity has long been proposed to play a role in aggression, but the results across studies have been mixed. One possible explanation for the mixed results is that impulsivity is a multifaceted construct and some, but not all, facets are related to aggression. The goal of the current meta-analysis was to determine the relation between the different facets of impulsivity (i.e., negative urgency, positive urgency, lack of premeditation, lack of perseverance, and sensation seeking) and aggression. The results from 93 papers with 105 unique samples (N = 36, 215) showed significant and small-to-medium correlations between each facet of impulsivity and aggression across several different forms of aggression, with more impulsivity being associated with more aggression. Moreover, negative urgency (r = .24, 95% [.18, .29]), positive urgency (r = .34, 95% [.19, .44]), and lack of premeditation (r = .23, 95% [.20, .26]) had significantly stronger associations with aggression than the other scales (rs < .18). Two-stage meta-analytic structural equation modeling showed that these effects were not due to overlap among facets of impulsivity. These results help advance the field of aggression research by clarifying the role of impulsivity and may be of interest to researchers and practitioners in several disciplines.

Etude sur la teneur en pigment de frênes qui croissent dans des conditions différentes

1973 ◽  
Vol 37 ◽  
Author(s):  
N. Lust
Keyword(s):  
Chlorophyll A ◽  
Strong Influence ◽  
The Other ◽  
Pigment Content ◽  
Chlorophyll B ◽  
Light Quantity ◽  
Yellow Pigments ◽  
The One ◽  
Green Pigments

Pigment content of ashes grown up under different circumstances - The pigment content (chlorophyll a, chlorophyll b,  xanthophyll and carotene) has been researched with ashes grown up under  different light circumstances and varying in age and height.     The results prove that the general laws concerning the influence of light  on the pigment content, don’t always work.     The phenomen is very complex. The light quantity is very important in some  cases, but insignificant in others. It seems origin and height of plants have  a strong influence. The results prove also the influence of the environment  is much higher on small plants as on big ones.     The research indicates finally the correlation between the green pigments,  the yellow pigments, and between the green pigments on the one side and the  yellow ones on the other side.

scholarly journals Enhanced Power Extraction with Sediment Microbial Fuel Cells by Anode Alternation

Fuels ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 168-178
Author(s):  
Marzia Quaglio ◽  
Daniyal Ahmed ◽  
Giulia Massaglia ◽  
Adriano Sacco ◽  
Valentina Margaria ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Energy Harvesting ◽  
Power Density ◽  
Microbial Fuel Cells ◽  
Average Power ◽  
Power Extraction ◽  
Harvesting Technique ◽  
Harvesting Method ◽  
Energy Harvesting Devices ◽  
Efficient Power

Sediment microbial fuel cells (SMFCs) are energy harvesting devices where the anode is buried inside marine sediment, while the cathode stays in an aerobic environment on the surface of the water. To apply this SCMFC as a power source, it is crucial to have an efficient power management system, leading to development of an effective energy harvesting technique suitable for such biological devices. In this work, we demonstrate an effective method to improve power extraction with SMFCs based on anodes alternation. We have altered the setup of a traditional SMFC to include two anodes working with the same cathode. This setup is compared with a traditional setup (control) and a setup that undergoes intermittent energy harvesting, establishing the improvement of energy collection using the anodes alternation technique. Control SMFC produced an average power density of 6.3 mW/m2 and SMFC operating intermittently produced 8.1 mW/m2. On the other hand, SMFC operating using the anodes alternation technique produced an average power density of 23.5 mW/m2. These results indicate the utility of the proposed anodes alternation method over both the control and intermittent energy harvesting techniques. The Anode Alternation can also be viewed as an advancement of the intermittent energy harvesting method.

scholarly journals Double-Deck Metal Solenoids 3D Integrated in Silicon Wafer for Kinetic Energy Harvester

Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 74
Author(s):  
Nianying Wang ◽  
Ruofeng Han ◽  
Changnan Chen ◽  
Jiebin Gu ◽  
Xinxin Li
Keyword(s):  
Kinetic Energy ◽  
Power Density ◽  
Energy Harvester ◽  
High Efficiency ◽  
Vibrational Energy ◽  
Average Power ◽  
Wafer Level ◽  
Peak Voltage ◽  
Silicon Mold ◽  
Casting Technique

A silicon-chip based double-deck three-dimensional (3D) solenoidal electromagnetic (EM) kinetic energy harvester is developed to convert low-frequency (<100 Hz) vibrational energy into electricity with high efficiency. With wafer-level micro electro mechanical systems (MEMS) fabrication to form a metal casting mold and the following casting technique to rapidly (within minutes) fill molten ZnAl alloy into the pre-micromachined silicon mold, the 300-turn solenoid coils (150 turns for either inner solenoid or outer solenoid) are fabricated in silicon wafers for saw dicing into chips. A cylindrical permanent magnet is inserted into a pre-etched channel for sliding upon external vibration, which is surrounded by the solenoids. The size of the harvester chip is as small as 10.58 mm × 2.06 mm × 2.55 mm. The internal resistance of the solenoids is about 17.9 Ω. The maximum peak-to-peak voltage and average power output are measured as 120.4 mV and 43.7 μW. The EM energy harvester shows great improvement in power density, which is 786 μW/cm3 and the normalized power density is 98.3 μW/cm3/g. The EM energy harvester is verified by experiment to be able to generate electricity through various human body movements of walking, running and jumping. The wafer-level fabricated chip-style solenoidal EM harvesters are advantageous in uniform performance, small size and volume applications.

Evaluation of fouling potential and power density in pressure retarded osmosis (PRO) by fouling index

Desalination ◽  
2016 ◽  
Vol 389 ◽  
pp. 215-223 ◽  
Author(s):  
Youngkwon Choi ◽  
Saravanamuthu Vigneswaran ◽  
Sangho Lee
Keyword(s):  
Power Density ◽  
Pressure Retarded Osmosis

scholarly journals Thermodynamics Evaluation of a Solar-biomass Power Generation System Integrated a Two-stage Gasifier

2016 ◽  
Vol 88 ◽  
pp. 368-374 ◽  
Author(s):  
Zhang Bai ◽  
Qibin Liu ◽  
Hui Hong ◽  
Hongguang Jin
Keyword(s):  
Power Generation ◽  
Generation System ◽  
Two Stage ◽  
Power Generation System

KINETIC INDICATORS OF TRAINING METHODS AND SELECTION OF YOUNG ROWERS

sportlogia ◽  
2021 ◽  
Vol 17 (1) ◽  
pp. 13-24
Author(s):  
Željko M. Rajković ◽  
◽  
Darko N. Mitrović ◽  
Vladimir K. Miletić ◽  
Petar M. Spaić ◽  
...  
Keyword(s):  
Average Power ◽  
The Other ◽  
Training Methods ◽  
Average Force ◽  
Other Hand ◽  
The World ◽  
Strict Selection ◽  
Selection Of

Modern diagnostics in rowing enables more and more possibilities for recording, and comparing numerous stroke variables. At the same time, many coaches fall into the trap of strict respect for the prescribed norms, ratios, and temporarily results, which the athlete must achieve if he wants to stay in the world of competitive rowing. On the example of the comparison of rowing schools RC "Danubius" and RC "Partizan", descriptive indicators are on the side of RC "Danubius" at a time of 2000m, average force and average power. No significant differences were found in average force (sig = 0,167) between rowers of RC "Danubius" and RC "Partizan", while statistically significant differences were recorded in time at 2000m (sig = 0,036) and power (sig = 0,02) in favor of rowers of RC “Danubius”. On the other hand, a higher correlation of average force (-0,955) and power (-0,928) with time on 2000m was achieved by RC "Partizan" than RC "Danubius" (-0,931) and (-0,896). The correlation between the average force, and the average power within one team shows a higher correlation for RC “Partizan" (0,95) compared to RC "Danubius" (0,755). The obtained results are not enough for single rower or crew elimination from competition to recreational section in the process of too frequent and strict selection of rowers, considering different possible ways of building rowing techniques and numerous parasitic factors that may affect measured variables, specialy at the age under 14 and novice rowers in general.

Nonlinear Stochastic Feedback Controllers for Vibratory Energy Harvesters With Power Flow Constraints

2011 ◽  
Author(s):  
Ian L. Cassidy ◽  
Jeffrey T. Scruggs ◽  
Sam Behrens
Keyword(s):  
Power Generation ◽  
Power Flow ◽  
Flow Direction ◽  
Average Power ◽  
Control Input ◽  
Stochastic Disturbances ◽  
Feedback Controllers ◽  
Energy Harvesters ◽  
System States ◽  
Feedback Laws

This study addresses the formulation of feedback controllers for stochastically-excited vibratory energy harvesters. Maximizing power generation from stochastic disturbances can be accomplished using LQG control theory, with the transducer current treated as the control input. For the case where the power flow direction is unconstrained, an electronic drive capable of extracting as well as delivering power to the transducer is required to implement the optimal controller. It is demonstrated that for stochastic disturbances characterized by second-order, bandpass-filtered white noise, energy harvesters can be passively tuned such that optimal stationary power generation only requires half of the system states for feedback in the active circuit. However, there are many applications where the implementation of a bi-directional power electronic drive is infeasible, due to the higher parasitic losses they must sustain. If the electronics are designed to be capable of only single-directional power flow (i.e., where the electronics are incapable of power injection), then these parasitics can be reduced significantly, which makes single-directional converters more appropriate at smaller power scales. The constraint on the directionality of power flow imposes a constraint on the feedback laws that can be implemented with such converters. In this paper, we present a sub-optimal nonlinear control design technique for this class of problems, which exhibits an analytically computable upper bound on average power generation.

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