Determination of the Solid Volume Percentage below Detectable Size in Coulter-counter Analysis

Nature ◽  
1966 ◽  
Vol 210 (5037) ◽  
pp. 765-766 ◽  
Author(s):  
R. K. ECKHOFF
REAKTOR ◽  
2012 ◽  
Vol 14 (2) ◽  
pp. 109 ◽  
Author(s):  
Yuswan Muharam ◽  
Chandra Hadiwijaya ◽  
Jacquin Suryadi

One of the characteristics of gasoline fuel is anti-knock property represented by its octanenumber. The determination of octane numbers in Indonesia is by using cooperative fuel researchengines. The usage of cooperative fuel research engines in Indonesia has constraints, i.e. the limitednumber of the units and the old age. This study aims to obtain the octane numbers of commercialfuels by using kinetic models. The kinetics models of the oxidation and combustion of primaryreference fuel and multi component hydrocarbons are used to calculate the ignition delay times ofprimary reference fuel and commercial fuels, respectively. The ignition delay times of primaryreference fuel and commercial fuels are calculated at the same initial pressure and temperature, aswell as the same equivalence ratio. The octane number of a commercial fuel is known if its ignitiondelay time agrees with that of PFR possessing a certain volume percentage of isooctane. The modelgenerates the octane numbers of commercial fuels BB-A being 92.5, BB-B being 94.5, BB-C being89, BB-D being 90.5 and BB-E being 91.5 with the good agreement with those claimed by the fuelproducers. Salah satu karakteristik bahan bakar bensin adalah sifat anti ketukan yang dinyatakan dengan angkaoktana. Penentuan angka oktana di Indonesia menggunakan mesin CFR (cooperative fuel research).Pemakaian mesin CFR di Indonesia memiliki kendala, yaitu jumlah unit terbatas dan usia tua.Penelitian ini bertujuan mendapatkan angka oktana bahan bakar komersial dengan menggunakanmodel kinetika. Model kinetika oksidasi dan pembakaran bahan bakar rujukan utama dan modelhidrokarbon multikomponen yang telah divalidasi masing-masing digunakan untuk menghitungwaktu tunda ignisi bahan bakar rujukan utama dan bahan bakar komersial. Waktu tunda ignisibahan bakar rujukan utama dan bahan bakar komersial dihitung pada tekanan dan temperatur awal,serta rasio ekuivalensi yang sama. Angka oktana suatu bahan bakar komersial diketahui apabilawaktu tunda ignisinya cocok dengan waktu tunda ignisi bahan bakar rujukan utama yang memilikipersen volume isooktana tertentu. Model menghasilkan angka oktana bahan bakar komersial BB-Asebesar 92,5, BB-B 94,5, BB-C 89, BB-D 90,5 dan BB-E 91,5 yang memiliki ketepatan yang tinggiterhadap klaim produser bahan bakar komersial.


1992 ◽  
Vol 70 (S1) ◽  
pp. S323-S333 ◽  
Author(s):  
H. K. Kimelberg ◽  
E. R. O'Connor ◽  
P. Sankar ◽  
C. Keese

In this paper we present an overview of methods for determining cell volume in both suspension and monolayer cultures. Data from the use of selected methods such as the Coulter counter system for suspension cultures and radiolabelled intracellular markers for substratum-attached, monolayer cultures are presented. The advantages, limitations, and conditions under which the different methods can be used are discussed. It is pointed out that there is a need for more direct physical methods for measuring dynamic changes in the cell volume of monolayer cultures without removing the cells from the substratum. Data from a method applicable to such cultures that measures extracellular impedance are presented.Key words: cell volume, monolayer cultures, extracellular impedance, radiolabelled intracellular markers, primary astrocyte cultures.


1986 ◽  
Vol 168 (3) ◽  
pp. 1466-1467 ◽  
Author(s):  
H E Kubitschek ◽  
J A Friske

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