scholarly journals Performance of Roasted Cocoa Bean Winnower For Small Holder Chocolate Producers

2016 ◽  
Vol 32 (2) ◽  
pp. 120-129
Author(s):  
Hendy Firmanto ◽  
Lya Aklimawati ◽  
Bayu Setyo Abdurrizal
Keyword(s):  
Energy Consumption ◽  
Variance Analysis ◽  
Transfer Efficiency ◽  
Cocoa Bean ◽  
Power Transfer ◽  
Machine Performance ◽  
Power Transfer Efficiency ◽  
Working Performance ◽  
Operation Results ◽  
Suction Rate

Cocoa bean winnowing has a function to separate cocoa nibs from shell after roasting process of dry bean. Nibs are further processed into fine cocoa liquor by refining process. The aim of this experiment was to evaluate working performance of a home-scale winnower to separate shell from nibs with minimum shell parchment content in cocoa nibs. This experiment was conducted in Postharvest Laboratory at the Indonesian Coffee and Cocoa Research Institute using roasted cocoa bean grade A according to standard of SNI 2323:2008/ Amd1:2010 with shell content of 15% originated from Forastero cocoa. Working performance of the home-scale winnower was evaluated based on shell parchment content in the output, its capacity, energy consumption and power transfer efficiency value by several air suction rates as variable. Data were analyzed using regression and variance analysis to evaluate the influence of the rate and to determine the optimum machine operation. Results of regression and variance analysis from winnowing experiment with air suction rate of 0.54 m/s; 0.63 m/s; 0.72 m/s and 0.90 m/s indicated that shell parchment content in cocoa nibs and power transfer efficiency value were affected by the rate. The optimum machine performance was obtained on 0.72 m/s of air suction rate with total winnowing capacity was 2.615 kg/hour, energy consumption of 132 Watt, power transfer efficiency value of 61.01% and shell parchment content was 1.06%. Shell parchment content in cocoa nibs was appropriate regarding to the SNI standard with maximum content of 1.75%.

scholarly journals Maximizing Transfer Efficiency with an Adaptive Wireless Power Transfer System for Variable Load Applications

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1417
Author(s):  
Jung-Hoon Cho ◽  
Byoung-Hee Lee ◽  
Young-Joon Kim
Keyword(s):  
Loading Condition ◽  
Wireless Power Transfer ◽  
Input Voltage ◽  
Transfer Efficiency ◽  
Maximum Efficiency ◽  
Variable Load ◽  
Power Transfer ◽  
Wireless Power ◽  
Variable Loading ◽  
Power Transfer Efficiency

Electronic devices usually operate in a variable loading condition and the power transfer efficiency of the accompanying wireless power transfer (WPT) method should be optimizable to a variable load. In this paper, a reconfigurable WPT technique is introduced to maximize power transfer efficiency in a weakly coupled, variable load wireless power transfer application. A series-series two-coil wireless power network with resonators at a frequency of 150 kHz is presented and, under a variable loading condition, a shunt capacitor element is added to compensate for a maximum efficiency state. The series capacitance element of the secondary resonator is tuned to form a resonance at 150 kHz for maximum power transfer. All the capacitive elements for the secondary resonators are equipped with reconfigurability. Regardless of the load resistance, this proposed approach is able to achieve maximum efficiency with constant power delivery and the power present at the load is only dependent on the input voltage at a fixed operating frequency. A comprehensive circuit model, calculation and experiment is presented to show that optimized power transfer efficiency can be met. A 50 W WPT demonstration is established to verify the effectiveness of this proposed approach.

scholarly journals Magnetic nozzle radiofrequency plasma thruster approaching twenty percent thruster efficiency

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kazunori Takahashi
Keyword(s):  
Magnetic Field ◽  
Electric Propulsion ◽  
Transfer Efficiency ◽  
Rf Plasma ◽  
Power Transfer ◽  
Rf Power ◽  
Plasma Production ◽  
Magnetic Nozzle ◽  
Plasma Thruster ◽  
Power Transfer Efficiency

AbstractDevelopment of a magnetic nozzle radiofrequency (rf) plasma thruster has been one of challenging topics in space electric propulsion technologies. The thruster typically consists of an rf plasma source and a magnetic nozzle, where the plasma produced inside the source is transported along the magnetic field and expands in the magnetic nozzle. An imparted thrust is significantly affected by the rf power coupling for the plasma production, the plasma transport, the plasma loss to the wall, and the plasma acceleration process in the magnetic nozzle. The rf power transfer efficiency and the imparted thrust are assessed for two types of rf antennas exciting azimuthal mode number of $$m=+1$$ m = + 1 and $$m=0$$ m = 0 , where propellant argon gas is introduced from the upstream of the thruster source tube. The rf power transfer efficiency and the density measured at the radial center for the $$m=+1$$ m = + 1 mode antenna are higher than those for the $$m=0$$ m = 0 mode antenna, while a larger thrust is obtained for the $$m=0$$ m = 0 mode antenna. Two-dimensional plume characterization suggests that the lowered performance for the $$m=+1$$ m = + 1 mode case is due to the plasma production at the radial center, where contribution on a thrust exerted to the magnetic nozzle is weak due to the absence of the radial magnetic field. Subsequently, the configuration is modified so as to introduce the propellant gas near the thruster exit for the $$m=0$$ m = 0 mode configuration and the thruster efficiency approaching twenty percent is successfully obtained, being highest to date in the kW-class magnetic nozzle rf plasma thrusters.

Wireless Power Transfer Systems via Strong Coupled Magnetic Resonances — Design, PCB Implementation and Tests

2011 ◽  
Vol 383-390 ◽  
pp. 5984-5989
Author(s):  
Yan Ping Yao ◽  
Hong Yan Zhang ◽  
Zheng Geng
Keyword(s):  
Printed Circuit Board ◽  
Experimental System ◽  
Wireless Power Transfer ◽  
Circuit Board ◽  
Transfer Efficiency ◽  
Power Transfer ◽  
Wireless Power ◽  
Power Transfer Efficiency ◽  
Coil Winding ◽  
Magnetic Resonances

In this paper, we present theoretical analysis and detailed design of a class of wireless power transfer (WPT) systems based on strong coupled magnetic resonances. We established the strong coupled resonance conditions for practically implementable WPT systems. We investigated the effects of non-ideal conditions presented in most practical systems on power transfer efficiency and proposed solutions to deal with these problems. We carried out a design of WPT system by using PCB (Printed Circuit Board) antenna pair, which showed strong coupled magnetic resonances. The innovations of our design include: (1) a new coil winding pattern for resonant coils that achieves a compact space volume, (2) fabrication of resonant coils on PCBs, and (3) integration of the entire system on a pair of PCBs. Extensive experiments were performed and experimental results showed that our WPT system setup achieved a guaranteed power transfer efficiency 14% over a distance of two times characteristic length(44cm). The wireless power transfer efficiency in this PCB based experimental system was sufficiently high to lighten up a LED with a signal generator.

Simulating Ultrasound Piezoelectric Power Transfer in the Near Field and Experimental Validations

2021 ◽  
Vol 05 ◽  
Author(s):  
Ammar Mohammed ◽  
Changki Mo ◽  
John Miller ◽  
David Lowry ◽  
Jassim Alhamid
Keyword(s):  
Energy Transfer ◽  
Lead Zirconate Titanate ◽  
Near Field ◽  
Acoustic Power ◽  
Acoustic Energy ◽  
Transfer Efficiency ◽  
Ultrasonic Power ◽  
Power Transfer ◽  
Piezoelectric Energy ◽  
Power Transfer Efficiency

Background: Acoustic power transfer is a method for wireless energy transfer to implanted medical devices that permits a greater range of separation between transmitter and receiver than is possible with inductive power transfer. In some cases, short-distance ultrasonic power transfer may be employed; consequently, their operation may be complicated by the near-field aspects of piezoelectric acoustic energy transfer. Methods: A piezoelectric energy transfer system consisting of two lead zirconate titanate (PZT) transducers was analyzed in this work using a combination of experimental measurements and computer simulations. Results: Simulations using the COMSOL Software package showed good agreement with a measured output voltage as a function of the distance between and alignment of the transmitter and receiver with water as a medium. We also simulated how operating frequency affects power transfer efficiency at various distances between the transmitter and receiver and found reasonable agreement with experiments. We report model predictions for power transfer efficiency as a function of the thickness and diameter of the transmitter and receiver. Conclusion: The results show that with proper choice of parameters, piezoelectric systems can provide high power transfer efficiency in the near-field region.

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