In the present research, we experimentally verified the partial-fill effect in a multicycle pulse detonation rocket engine. The intermittent thrust of a pulse detonation rocket engine was measured by using a spring-damper mechanism that smoothed this intermittent thrust in the time direction. The intermittent mass flow rates were assessed by gas cylinder pressure or mass difference measurement. The maximum specific impulse was 305 9 s at an ethylene and oxygen propellant fill fraction of 0:130 0:004. When the fill fraction was greater than 0.130, the specific impulse was increased as the partial-fill fraction was decreased. When the fill fraction was less than 0.130, the specific impulse was sharply decreased as the partial-fill fraction was decreased. This decrease was due to diffusion between propellant and purge gases and the short length of the transition from deflagration to detonation. The multicycle pulse detonation rocket engine had a partial-fill effect that may have been mainly due to the suctioned air and was consistent with the single-cycle partial-fill model of Endo et al. NomenclatureA e = control-volume surface area through which an exhaust jet flows c = attenuation coefficient of a damper F f = force acting on the pulse detonation engine tube by the rail in the x direction F kc = force acting on the pulse detonation engine tube by the spring-damper system in the x direction F lc = force acting on the spring-damper system by the load cell in the x direction F p = force acting on the pulse detonation engine tube by the fluid in the x direction F t = force acting on the pulse detonation engine tube by the supplying tubes in the x direction F 0 = plateau thrust ff air;est = estimated suctioned air fill fraction ff propellant = propellant fill fraction ff purge = purge gas fill fraction g = gravitational acceleration I = impulse acting on the pulse detonation engine tube by the fluid in the x direction I sp = specific impulse I total = absolute value of the total impulse acting on the pulse detonation engine tube by the fluid in the x direction during all cycles I total;x = total impulse acting on the pulse detonation engine tube by the fluid in the x direction during all cycles k = spring constant M c = molecular weight in the cylinder m d = mass of weight m propellant = propellant mass during all of the cycles m purge = purge gas mass during all of the cycles m t = pulse detonation engine tube mass p a = ambient pressure around the control volume p e = exhausted-jet pressure on the control surface R c = gas constant of the gas in the cylinder T c = gas temperature in the cylinder t = time t cyc = period of one cycle t pl = time during which the plateau thrust is maintained t total = time during all of the cycles u e = fluid velocity component in the x direction, on the control surface u x = fluid velocity component in the x direction V = volume V c = volume of the cylinder v s = horizontal velocity of a solid element v w = velocity of the weight x = horizontal axis fixed in the control volume x p = p...
Chromosome 12q15 microdeletion syndrome is characterized by intellectual disability and dysmorphic facial features, but the associations between each of the deleted genes and the phenotypes of 12q15 microdeletion syndrome remain unclear. Recently, the smallest region of overlap in 16 previously reported patients was used to define three candidate genes for the 12q15 microdeletion syndrome: CNOT2, KCNMB4, and PTPRB. Among these three candidate genes, CNOT2 maintains the structural integrity of the carbon catabolite repressor 4 (CCR4)‐negative on TATA (NOT) complex, which plays a key role in regulating global gene expression, and is essential for the enzymatic activity of the CCR4‐NOT complex. Disruption of the CCR4‐NOT complex results in dysregulation of global gene expression, and is associated with various human disease processes, including neuronal diseases. Therefore, CNOT2 haploinsufficiency might account for the neurological features of the 12q15 microdeletion syndrome. Herein, we document a 12‐year‐old female patient with mild intellectual disability and multiple structural abnormalities including cleft lip and palate and 2–3 toe syndactyly. She exhibited dysmorphic facial features such as upslanting and short palpebral fissures, micrognathia, low‐set ears, and hypoplastic antihelix. A microarray analysis showed a de novo 1.32‐Mb deletion within 12q15 that included CNOT2 and 14 other genes. Remapping of the 12q15 deletion region in the 16 previously reported patients together with that in the newly identified patient indicated that CNOT2 is the only gene that is commonly deleted. These findings suggest that CNOT2 is the prime candidate for the neurological phenotypes of the 12q15 microdeletion syndrome.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.