23,658 research outputs found
Analysis and observation of grid connected single phase inverter integration
A single-phase grid connected with a photovoltaic (PV) power system that will provide
high voltage gain with state model analysis for the control of the system has been
presented. In addition to the solar panels, the system is equipped with a dc–dc
converter, which allows the panels’ maximum power point to be tracked, a singlephase
inverter and PI controller, all connected to a single-phase utility grid. The
maximum power point is maintained with a perturb and observe method. A PI
controller is used to control the power injected into the grid. The controller is used to
generate PWM and also controlling extra power. The maximum power delivered, and
it is synchronized with help of PWM to improve the power quality and system
efficiency. In this project the design separated in closed loop and open loop designs.
The result in both designs are different where is the voltage will be increase up to
3.214% more in closed loop design. Also, the power will increase up to 27.78% in
closed loop design
Selective RF wireless control of integrated bulk-micromachined shape-memory-alloy actuators and its microfluidic application
This paper reports wireless microfluidic control enabled by selective operation of multiple bulk-micromachined shape-memory-alloy actuators using radiofrequency external magnetic fields. Each shape-memory-alloy actuator is driven by a wireless resonant heater, which generates heat only when the field frequency is tuned to the resonant frequency of the heater. Multiple actuators coupled with the heater circuits that are designed to have different resonant frequencies in a range of 135-295 MHz are selectively controlled by modulating the field frequency to the resonant frequencies of the corresponding heaters with a constant output power. A wireless microsyringe device that has three actuator-heater components and a flexible parylene reservoir is developed. The 5-µl reservoir is squeezed by the 5-mm-long cantilever-type SMA actuators to eject controlled amounts of liquid from the reservoir. Wireless modification of pH in liquid is demonstrated using the device loaded with acidic solution through the selective control of the three actuators based on the frequency modulation technique
Inversion of the Dual Dunkl-Sonine Transform on R Using Dunkl Wavelets
We prove a Calder\'on reproducing formula for the Dunkl continuous wavelet
transform on . We apply this result to derive new inversion
formulas for the dual Dunkl-Sonine integral transform
Satu tinjauan keperluan kod etika gangguan seksual di kalangan penuntut-penuntut politeknik
Kajian ini bertujuan untuk meninjau bahawa adakah kod etika gangguan
seksual diperliikan oleh penuntut-peniintut politeknik Keperluan penghasilan kod
etika ini adalah untuk memberi pengetahuan, kesedaran dan kefahaman kepada
penuntut-penuntut politeknik terhadap gejala gangguan seksual ini. Sebanyak tiga
buah Politeknik yang terlibat iaitu Politeknik Port Dickson, Politeknik Sultan
Sallahuddin Abdul Aziz Shah dan Politeknik Seberang Perai. Seramai 100 orang
penuntut dari ketiga-tiga buah politeknik yang terlibat dalam kajian ini. Kajian ini
adalah berbentuk deskriptif iaitu melalui teknik peninjauan ke atas sainpel. Fungsi
mereka ini hanyalah sebagai pemberi maklumat. Bagi tujuan mengumpul data, soal
selidik berdasarkan skala Likert ditadbirkan kepada pelajar-pelajar. Data-data yang
diperolehi dianalisis menggunakan ujian statistik dengan perisian SPSS versi 10.0.
Hasil kajian menunjukkan bahawa penuntut-penuntut mempimyai pengetahuan,
kesedaran dan kefahaman yang sederhana mengenai gangguan seksual. Oleh itu,
mereka bersetuju jika diwujudkan satu kod etika sebagai satu garis panduan. Dengan
dapatan ini maka ia boleh memberi input kepada pihak yang terbabit untuk
menangani isu gejala gangguan seksual ini
Frequency-controlled wireless shape-memory-alloy microactuators integrated using an electroplating bonding process
This paper reports the wireless control of bulk-micromachined shape-memory-alloy actuators using external radiofrequency magnetic fields and its application to microgrippers. The frequency-sensitive wireless resonant heater to which the gripper actuator is bonded is activated only when the field frequency is tuned to the resonant frequency of the heater. A batch-compatible bonding technique based on photo-defined copper electroplating is developed to mechanically and thermally couple the gripper with the planar heater circuit fabricated using copper-clad polyimide film. The actuation range of 600 µm as the tip opening distance is obtained with normally closed 5-mm long grippers at a device temperature of 92 °C. The field frequency range to which the devices with 140-MHz resonant frequency respond is measured to be ~13 MHz about the resonant frequency. The manipulation of vertically aligned carbon-nanotube forests is experimentally demonstrated. Mechanical stress tests for the bond formed by the developed electroplating bonding method show a shear strength greater than 40 MPa
CAPITAL ACCOUNT LIBERALIZATION AND EXCHANGE RATE REGIME CHOICE, WHAT SCOPE FOR FLEXIBILITY IN TUNISIA?
Capital account liberalization and exchange rate regime choice, what scope for flexibility in Tunisia? This study evaluates within a game-theoretic framework the exchange rate regime from a welfare perspective. In a tradable-nontradable goods model framework, Tunisia’s exchange rate regime choice is cast in terms of strategic interactions between the monetary authority and domestic enterprises. The monetary authority is assumed to choose an optimal exchange rate regime according to a welfare-related criterion by minimising a loss function defined in terms of external competitiveness and domestic inflation. Simulations outcomes reveal that capital account liberalization in the Tunisian economic context is compatible with a flexible exchange rate regime.http://deepblue.lib.umich.edu/bitstream/2027.42/40201/3/wp815.pd
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