scholarly journals Revolutionizing Spaceflight: A Study on Electric Propulsion and Air-Breathing MPDs

2021 ◽  
Vol 10 (2) ◽  
Author(s):  
Ian McKinney ◽  
John Murnan
Keyword(s):  
Experimental Study ◽  
Electric Propulsion ◽  
Liquid Fuel ◽  
Specific Impulse ◽  
Atmospheric Conditions ◽  
Air Breathing ◽  
Rocket Propulsion ◽  
Hall Effect Thrusters ◽  
Quasi Experimental ◽  
Mirror Reflectance

Modern liquid-fuel rocket propulsion harbors a number of great limitations. Among those is the weight of fuel, which makes up more than 90% of the mass of the SpaceX Falcon 9 (NASA, 2018). Electric propulsion has been used for decades as an alternative to liquid-fuel rockets due to low propellant requirements and high specific impulse. Although electric thrusters have strictly been used in non-atmospheric conditions, recent innovations attempt to expand its use to airspace. This quasi-experimental study focuses on the creation of an air-breathing magnetoplasmadynamic (MPD) thruster, with attempts being made to maximize the efficiency of the engine. Immense safety concerns prevented testing from occurring after the engine was built. However, the estimated performance of the built MPD is compared to a multitude of existing forms of electric propulsion, from Hall-effect thrusters to electrodynamic tethers. The concluding evidence suggests that air-breathing MPDs are not currently viable, high-power photon thrusters being of greater use in atmospheric conditions. Further research focusing on decreasing atmospheric breakdown voltage and increasing mirror reflectance of photon thrusters is suggested.

DESAIN PEMBELAJARAN BAHASA INDONESIA BERBASIS PEMAHAMAN NILAI SIKAP GOTONG ROYONG

2020 ◽  
Vol 13 (2) ◽  
pp. 01-10
Author(s):  
Alpansyah Alpansyah ◽  
Abdul Talib Hasim
Keyword(s):  
Experimental Study ◽  
Language Learning ◽  
Reader Response ◽  
Female Students ◽  
Male Students ◽  
Mutual Cooperation ◽  
Male And Female ◽  
Quasi Experimental ◽  
Bahasa Indonesia ◽  
Better Than

The aims of this study were: (1) to identify an increase in students' understanding of the value of mutual cooperation through the use of reader response rules in Indonesian Language Learning (KRPDPBI); (2) identifying the use of the reader response principle in Indonesian Language learning (KRPDPBI) there are differences between male and female students. The design of this study used a quasi-experimental study with two different methods. The results showed that (1) the achievement of the score of understanding the value of mutual cooperation for students taught by KRPDPBI was better than for students taught by regular learning according to the curriculum; (2) the achievement of the understanding of the value of male students' mutual cooperation is no better than that of female students.

A Quasi-Experimental Study on the Target Hardening CPTED for Preventing Burglary

2019 ◽  
Vol 10 (1) ◽  
pp. 7-32
Author(s):  
Kang-Il Kim ◽  
Joon-Tag Cho ◽  
Hyeon-Ho Park
Keyword(s):  
Experimental Study ◽  
Target Hardening ◽  
Quasi Experimental

Peningkatan Pengetahuan Calon Pengantin Melalui Konseling ASI Eksklusif di Kecamatan Darul Imarah Aceh Besar

2017 ◽  
Vol 19 (1) ◽  
pp. 36-42
Author(s):  
Agus Hendra Al-Rahmad
Keyword(s):  
Experimental Study ◽  
Exclusive Breastfeeding ◽  
Action Plan ◽  
Scaling Up ◽  
Random Assignment ◽  
Nutrition And Health ◽  
Face To Face ◽  
Child Stunting ◽  
Quasi Experimental ◽  
Breastfeeding Counseling

Background : Scaling Up Nutrition movement is a global effort to strengthen our commitment and accelerating action plan to improve nutrition, particularly the handling of nutrition in the first 1,000 days of life is exclusive breastfeeding and it until 24 months. One of the way is with exclusive breastfeeding counselling that can reduce stunting. The counseling is addressed to brides who need special attention in improving the nutrition and health. Objective : The aim of research to improve knowledge about exclusive breastfeeding counseling the bride through the use of leaflets. Method : This quasi-experimental study was a sample of 30 person a brides with non-random assignment, the variable a knowledge obtained through interviews using questionnaires while the method of counseling does face to face with an exclusive breastfeeding leaflet. The data was analyzed by dependent t-test. Result : The results showed exclusive breastfeeding counseling can improve knowledge bride (p= 0,000) with a mean difference is 6,13 and a deviation is 3,71. Conclusion : Increase of knowledge among ‘bride-to be’ about exclusive breastfeeding could be improved through the use of exclusive breastfeeding leaflet. Each health center must be in collaboration with Office of Religious Affairs to have exclusive breastfeeding counseling, and set one of the priority programs in the prevention of child stunting.   Keywords: Bride, counseling, knowledge of exclusive breastfeeding

A review of high-power magnetoplasmodynamic electric propulsion designs and studies of RSC Energia

2020 ◽  
pp. 112-133
Author(s):  
Victor V. SINYAVSKIY
Keyword(s):  
Service Life ◽  
Electric Power ◽  
High Power ◽  
Electric Propulsion ◽  
Nuclear Power ◽  
Materials Science ◽  
Low Voltage ◽  
Power Input ◽  
Design Bureau ◽  
Rocket Propulsion

At the initiative of S.P.Korolev, in 1959, Special Design Bureau No.1 (now RSC Energia) established the High-temperature Power Engineering and Electric Propulsion Center which was tasked with development of nuclear electric propulsion for heavy interplanetary vehicles. Selected as the source of electric power was a nuclear power unit based on a thermionic converter reactor, and selected as the engine was a stationary low-voltage magnetoplasmodynamic (MPD) high-power (0.5–1.0 MW) thruster which had thousands of hours of service life. The paper presents the results of extensive efforts in research, development, design, materials science experiments, and tests on the MPD-thruster, including the results of development and 500-hours life tests of an MPD-thruster with a 500-600 kW electric power input that used lithium propellant. The world’s first lithium 17 kW MPD-thruster was built and successfully tested in space. The paper points out that to this day nobody has surpassed the then achievements of RSC Energia neither in thruster output during long steady-state operation, nor in performance and service life. Key words: Martian expeditionary vehicle, nuclear electric rocket propulsion system, electric rocket thruster, magnetoplasmodynamic thruster, lithium, cathode, anode, barium, electric propulsion tests in space.

PENGELUARAN KOLOSTRUM DENGAN PEMBERIAN PERAWATAN PAYUDARA DAN ENDORPHIN MASSAGE PADA IBU POST SEKSIO SESAREA

2019 ◽  
Vol 2 (1) ◽  
pp. 34-40
Author(s):  
Diah Evawanna Anuhgera ◽  
Eka Fitria Panjaitan ◽  
Desika Wali Pardede ◽  
Desika Wali Pardede ◽  
Nikmah Jalilah Ritonga ◽  
...  
Keyword(s):  
Experimental Study ◽  
Cesarean Section ◽  
Alternative Therapy ◽  
Control Group ◽  
Control Group Design ◽  
Group Design ◽  
A Value ◽  
Quasi Experimental ◽  
Breast Care ◽  
June July

Spending colostrum in post-cesarean section mothers is difficult in the first week postpartum. Efforts to overcome colostrum disruption can use non-pharmacological methods, namely breast care and endorphin massage. This study aims to determine the expenditure of colostrum by giving breast care and endorphin massage to post-cesarean mothers. This research is a quasi-experimental study with a nonequivalent design posttest control group design. This research was carried out in the midwifery room of the second floor of Grand Medistra Lubuk Pakam Hospital during the June-July 2019 period. There were 48 participants selected using purposive sampling, with 18 assigned in breast care, endorphin massage and combination of breast care and endorphin massage. The time of spending colostrum expenditure is assessed every day while the amount of colostrum expenditure is assessed after intervening. Analysis of the data used is one-way Annova. The results showed that the combination of breast care and endorphin massage was the most effective action in the time of spending colostrum and the amount of colostrum with a value of p = 0,000. The combination of breast care and endorphin massage could be applied as an alternative therapy post-cesarean mothers    

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