scholarly journals Modeling Pluto’s minimum pressure: Implications for haze production

Icarus ◽  
2021 ◽  
Vol 356 ◽  
pp. 114070
Author(s):  
Perianne E. Johnson ◽  
Leslie A. Young ◽  
Silvia Protopapa ◽  
Bernard Schmitt ◽  
Leila R. Gabasova ◽  
...  
Keyword(s):  
2020 ◽  
Vol 87 (10) ◽  
pp. 630-636
Author(s):  
Oliver Slanina ◽  
Susanne Quabis ◽  
Robert Wynands

AbstractTo ensure the safety of users like hunters and sports shooters, the dynamic pressure inside an ammunition cartridge must not exceed a maximum value. We have investigated the reproducibility of the dynamic measurement of the gas pressure inside civilian ammunition cartridges during firing, when following the rules formulated by the Permanent International Commission for the Proof of Small Arms (C. I. P.). We find an in-house spread of 0.8 % between maximum and minimum pressure for runs with the same barrel and of 1.8 % among a set of three barrels. This sets a baseline for the expected agreement in measurement comparisons between different laboratories. Furthermore, a difference of more than 3 % is found in a preliminary study of the influence of ammunition storage conditions.


AIChE Journal ◽  
1974 ◽  
Vol 20 (5) ◽  
pp. 1034-1036 ◽  
Author(s):  
Chie Y. Lee ◽  
John A. Tallmadge
Keyword(s):  

Author(s):  
Teguh Taruna Utama

Drinking water sources in Manggarai Regency are mostly supplied from springs. Golo Wua and Golo Watu are two villages in Manggarai Regency that utilize springs. About 12.06 liters/second of drinking water are needed by residants in those villages. This study addresses to forecast the demand of drinking water. This study found that pressure values in manual calculations range from 1.85 meters to 84.22 meters. The minimum pressure requirements from BPP-SPAM is 7 meters (0.7 bar). While the simulation results using the EPANET program, the pressure value is at 1.90 meters up to 84.22 meters. Therefore, the pipe diameter selection is appropriate and the pressure meets the requirements of the BPP-SPAM. Difference between pressure values less than 5% indicates that the selection is the right pipe diameter. Choosing the right pipe diameter will optimize the distribution network in the villages of Golo Wua and Golo Watu. The selected pipe is HDPE type. Selected pipe diameter 1½"; 2"; 2½”; 3"; 4 and 5". The pipe has a pressure resistance of up to 125 meters.


2017 ◽  
Vol 5 (2) ◽  
Author(s):  
Yudi Prihadnyana ◽  
Gede Widayana ◽  
Kadek Rihendra Dantes

Dengan perkembangan teknologi yang semakin maju bentuk dari bodi sebuah kendaraan sangatlah diperhitungkan untuk mencapai tujuan-tujuan tertentu. Untuk itu, dilakukan analisis Aerodinamika pada pemukaan bodi mobil listrik gaski dengan menggunakan perangkat lunak Ansys 14.5, yang bertujuan untuk mengetahui aliran fluida dan nilai koefisient drag pada mobil listrik Gaski bodi standar dan modifikasi. Setelah proses analisis dilakukan, didapatkan hasil velocity udara maksimum body standar sebesar 17,4324 m/s dan body modifikasi sebesar 17,7321 m/s dan pressure maksimum yang terjadi pada mobil listrik Gaski body standar sebesar 83,2143 Pa, dan minimum sebesar -189,879 Pa. sedangkan pressure maksimum yang terjadi pada mobil listrik Gaski body modifikasi sebesar 83,2143 Pa. dan minimum pressure diperoleh -182,128 Pa. nilai Koefisient drag dari mobil listrik Gaski body standar sebesar 0,00474 sedangkan pada body modifikasi sebesar 0,00407. Dari hasil peneletian tersebut didapatkan bahwa setalah dilakukan modifikasi pada bodi mobil listrik gaski terdapat beberapa perubahan diantaranya terjadi peningkatan kecepatan laju aliran udara atau velocity udara meningkat 1,72 % sedangkan tekanan yang diterima oleh bodi setelah dimodifikasi menurun 1,39 % dan Nilai koefisien drag pada mobil listrik gaski dapat diturunkan 14,14 % setelah dimodifikasi.Kata Kunci : kata kunci : Aerodinamika, aliran fluida, bodi kendaraan, With the technological development of the more advanced form of the body of a vehicle is very calculated to achieve certain goals. For that purpose, Aerodynamic analysis was performed on the electric car body surface by using Ansys 14.5 software, which aims to find out the fluid flow and coefficient value of drag on electric car Gaski standard body and modification. After the analysis process is done, the result of the maximum air velocity of the standard body is 17,4324 m / s and body modification of 17,7321 m / s and the maximum pressure happened to electric car Gaski body standard equal to 83,2143 Pa, 189,879 Pa. While the maximum pressure that occurs on electric cars Gaski body modification of 83.2143 Pa. And the minimum pressure obtained -182.128 Pa. Coefficient value of drag from electric car Gaski body standard of 0,00474 while at body modification equal to 0,00407. From the results of the research was found that after modification on the body of electric car gaski there are some changes such as increase the speed of air flow rate or air velocity increased by 1.72%, while the pressure received by the body after modification decreased 1.39% and the value of drag coefficient on Electric car gaski can be derived 14.14% after modified.keyword : Keywords : Aerodynamic, fluid flow rate, Vehicle body.


1960 ◽  
Vol 82 (4) ◽  
pp. 941-945 ◽  
Author(s):  
J. W. Holl

The simultaneous occurrence of vaporous and gaseous cavitation on hydrofoils is considered. The experimental results show that gaseous cavitation occurs at much higher ambient pressures than that for the vaporous cavitation resulting in desinent-cavitation numbers twice the minimum-pressure coefficient of the hydrofoil. The analysis indicates that the difference between the desinent-cavitation number for the gaseous cavitation and that for the vaporous cavitation is proportional to the dissolved air content and inversely proportional to the square of the velocity.


1969 ◽  
Vol 116 (9) ◽  
pp. 1264 ◽  
Author(s):  
A. S. Jordan ◽  
R. R. Zupp
Keyword(s):  

1976 ◽  
Vol 40 (6) ◽  
pp. 915-922 ◽  
Author(s):  
D. G. Frazer ◽  
K. C. Weber

Degassed excised rat lungs were ventilated in a water-filled plethysmograph with the carina as the zero pressure reference. Pressure-volume curves were recorded from a minimum transpulmonary pressure (Pmin) of -5 cmH2O to a maximum pressure (Pmin) of 30 cmH2O. An index of the minimun volume for the lung (Vm) divided by the maximum lung volume for the same cycle (Vmax) was used as an index of the amount of air trapped within the lung. As the flow rate was decreased from 38.2 to 1.9 ml/min, there were significant increases in the amount of air trapped in the lung. As the maximum pressure was decreased to 25 and 20 cmH2O, or the minimum pressure was increased to 6 and 11 cmH2O, the amount of trapped air in the lung significantly decreased. The rate of lung inflation had a much greater influence on the amount of trapped air than either the deflation rate or stress relaxation. The results are consistent with the theory that bubbles are formed during inflation and are the main cause of air trapped in the excised lung.


Author(s):  
Chunqiang Zhang ◽  
Xiaomin Ji ◽  
Yanmin Xue ◽  
Gang Hu

Ankles can benefit from the elastic tube bandage (ETB) by providing the ankle joint with compression, but partial high- or low-pressure leads to body discomfort. The aim of this paper is to propose a method for analyzing the ankle shape with the fabric compression which is basis on the comfortable pressure on human body. First, a standard model of ankle is established from the scanned data of 306 samples, and the mapping of the fabric shape curves on ankle were constructed by the U-direction convex curves of the model. The positions or areas of maximum and minimum pressure are then marked by extracting the curvatures of the fabric shape curves. According to the Laplace’s Law, the sizes of ETBs can be calculated given that the value of comfortable pressure on human body is the maximum one. The data of calculation is approximate to the relevant previous studies which has the same parameters of ETBs. Nine groups of the ankle shapes from the database are discussed, each group has a proportional coefficient to the standard model, and the result shows that six sizes of ETBs with comfort pressure match for the nine groups. These can be applied to the comfort design, and the method proposed can boost size customization of ETBs, as well as will inspire the research on other elastic compression garments.


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