scholarly journals Chemical and Physical Properties of Soot as a Function of Fuel Molecular Structure in a Swirl-Stabilized Combustor

1984 ◽  
Vol 106 (1) ◽  
pp. 103-108 ◽  
Author(s):  
R. M. Himes ◽  
R. L. Hack ◽  
G. S. Samuelsen

Soot samples were extracted from a swirl-stabilized, liquid-fuel fired laboratory combustor to (i) assess the validity of the ASTM smoke point test in predicting the sooting characteristics of fuels in complex combustion systems and (ii) assess the effect of fuel molecular structure and smoke suppressant additives on the physical and chemical properties of soot. Fuels utilized were shale JP-8, iso-octane, and blends of iso-octane with either decalin, toluene, tetralin, or 1-methylnaphthalene such that smoke points similar to JP-8 were achieved. Each fuel was separately blended with 0.05 percent (by weight) ferrocene smoke suppressant. The results indicate that the ASTM test can be misleading, increased fuel molecular complexity increases soot content of higher molecular weight polycyclic aromatics, and ferrocene additive reduces small particle number density but not necessarily the soot mass loading.

Author(s):  
R. M. Himes ◽  
R. L. Hack ◽  
G. S. Samuelsen

Soot samples were extracted from a swirl-stabilized, liquid-fuel fired laboratory combustor to (i) assess the validity of the ASTM smoke point test in predicting the sooting characteristics of fuels in complex combustion systems and (ii) assess the effect of fuel molecular structure and smoke suppressant additives on the physical and chemical properties of soot. Fuels utilized were shale JP-8, isooctane, and blends of isooctane with either decalin, toluene, tetralin, or 1-methylnapthalene such that smoke points similar to JP-8 were achieved. Each fuel was separately blended with 0.05 percent (by weight) ferrocene smoke suppressant. The results indicate that the ASTM test can be misleading, increased fuel molecular complexity increases soot content of higher molecular weight polycyclic aromatics, and ferrocene additive reduces small particle number density but not necessarily the soot mass loading.


2011 ◽  
Vol 382 ◽  
pp. 372-374
Author(s):  
Yong Jiang ◽  
Zhi Bin Jiang ◽  
Guo Jie Shao ◽  
Dong Cheng Guo ◽  
Yu Tian ◽  
...  

Purpose: The purpose of this study was to study the compositions of the polygonaceae medicinal plants called rumex root. Methods: Solvent method and chromatography was used to purificate the chemical compositions of Rumex, and the molecular structure of the compound was identified by physical and chemical properties and spectral data. Results: Two compounds were obtained from the ethanol extract of rumex root, which were identified as Chrysophanol and Physcione. Conclusions: Experimental basis was provided for the further study of the active ingredients of rumex root and the development and utilization of medical resources.


2018 ◽  
Vol 74 (1-2) ◽  
pp. 25-33 ◽  
Author(s):  
Zahid Iqbal ◽  
Muhammad Ishaq ◽  
Adnan Aslam ◽  
Wei Gao

AbstractPrevious studies show that certain physical and chemical properties of chemical compounds are closely related with their molecular structure. As a theoretical basis, it provides a new way of thinking by analyzing the molecular structure of the compounds to understand their physical and chemical properties. The molecular topological indices are numerical invariants of a molecular graph and are useful to predict their bioactivity. Among these topological indices, the eccentric-connectivity index has a prominent place, because of its high degree of predictability of pharmaceutical properties. In this article, we compute the closed formulae of eccentric-connectivity–based indices and its corresponding polynomial for water-soluble perylenediimides-cored polyglycerol dendrimers. Furthermore, the edge version of eccentric-connectivity index for a new class of dendrimers is determined. The conclusions we obtained in this article illustrate the promising application prospects in the field of bioinformatics and nanomaterial engineering.


1979 ◽  
Vol 34 (9) ◽  
pp. 1279-1285 ◽  
Author(s):  
R. Tacke ◽  
M. Strecker ◽  
W. S. Sheldrick ◽  
E. Heeg ◽  
B. Berndt ◽  
...  

Abstract Sila-difenidol (6b), a sila-analogue of the drug difenidol (6a), was synthesized according to Scheme 1. 6b and its new precursors 3 and 5 were characterized by their physical and chemical properties, and their structures confirmed by elementary analyses, 1H NMR and mass spectroscopy. 6 b crystallizes orthorhombic P212121 with a = 11.523(1), b = 14.366(4), c = 11.450(1) Å, Z = 4, Dber = 1.14 gcm-3. The structure was refined to R = 0.050 for 1897 reflexions. A strong nearly linear intramolecular O-H···N hydrogen bond of 2.685 Å is observed. The anticholinergic, histaminolytic and musculotropic spasmolytic activities of 6 a and 6 b are reported.


2021 ◽  
Vol 6 (1) ◽  
pp. 771-778
Author(s):  
Yetunde Mary Iranloye ◽  
Fapojuwo Oladele Omololu ◽  
Abiola Folakemi Olaniran ◽  
Victoria Funmilayo Abioye

Abstract This study investigated the effects of mixing Moringa oleifera seed oil with soybean (Glycine max) seed oil in enhancing the physical and chemical properties of soybean oil during repetitive frying. Different blends (100:0, 50:50, and 70:30) of soybean and M. oleifera seed oils were formulated, while soybean oil served as control. All these oil samples were used for frying potato (Ipomoea batatas) slices. The quality of the fried oil samples was evaluated by determining the smoke point, refractive index (RI), viscosity, colour, peroxide value, iodine value, and free fatty acid (FFA). The range of values obtained were smoke point (158.7–172.3°C), RI (1.46–1.49°C), colour (6.0–9.42), viscosity (0.41–2.13 mm2/s), peroxide value (0.93–5.16 meq/kg), iodine value (87.16–64.71 mg/100 g), and FFA (0.3–1.95%), for different blends of soybean and M. oleifera seed oils and control. In terms of changes in the chemical and physical properties, during frying, soybean/M. oleifera seed oil mix of 70:30 had the lowest reduction in iodine value (87.56–68.73 mg/100 g), lowest increase in peroxide value (0.93–1.86 meq/kg) and FFA value (0.3–0.65%), while no changes in RI (1.47°C) was observed. The study revealed that mixing of soybean seed oil with M. oleifera seed oil at a ratio of 70:30 enhanced the physical and chemical properties of the soybean oil after two repetitive frying.


2018 ◽  
Vol 27 (1) ◽  
pp. 30-34 ◽  
Author(s):  
K. A. Bezruchko ◽  
L. I. Pymonenko ◽  
A. V. Burchak ◽  
D. A. Suvorov

This article discusses processes of rock-mass geothermal and geomechanical energy transfer on the nanolevel and describes different mechanisms of potential energy absorption, distribution and usage by the molecular structure of the coal substance. We show that mechanical and thermal energies in the molecular structure of the coal substance are transformed into quantum-mechanical energy which feeds the structural transformations and generation processes in the substance. At the nanolevel, the energy inflow transforms the atomic-molecular structure, changes the physical and chemical properties of the coal and may cause fluid (including methane) emission. The availability of a general solution for energetic problems of different hierarchical levels is evidence of the possibility of using a fractal approach for researching the energy re-distribution in the system.


Author(s):  
Afuape Zainab Oluwakemi ◽  
Oke Emmanuel Kehinde ◽  
Idowu Michael Ayodele ◽  
Olorode Omobolanle Omowunmi ◽  
Omoniyi Saheed Adewale

This study was carried out to investigate the physical and chemical properties of tigernut oil as influenced by variety and methods of extraction. Oil was extracted from yellow and brown varieties of tigernut using mechanical screw press and N-hexane, and it was characterized for physical and chemical composition. The moisture content, acid value, free fatty acid, iodine value, saponification value and peroxide value for tigernut oil from extraction methods ranged from 2.97 to 3.30%, 0.28 to 0.56mgKOH/g, 0.55 to 1.12g/100g, 66.11 to 69.75gI/100g, 174.93 to 210.06mgKOHg and 0.27 to 0.56MgH2O2, respectively. The range of values for specific gravity, percentage impurity, cloud point, smoke point and melting point are: 0.64 to 0.99g/ml, 0.15 to 0.24%, 9.00 to 25.5°C, 170.5 to 204.5°C and 18.0 to 28.5°C, respectively. However, the study showed that both the physical and chemical composition of tigernut oil were affected by the extraction methods used in this study.


Author(s):  
James E. Mark ◽  
Harry R. Allcock ◽  
Robert West

Polyphosphazenes comprise by far the largest class of inorganic macromolecules. At least 700 different polymers of this type have been synthesized, with a range of physical and chemical properties that rivals that known hitherto only for synthetic organic macromolecules. Most polyphosphazenes have the general molecular structure. The polymer backbone consists of alternating phosphorus and nitrogen atoms, with two side groups, R, being attached to each phosphorus. The side groups may be organic, organometallic, or inorganic units. Each macromolecule typically contains from 100 to 15,000 or more repeating units linked end to end, which means that (depending on the organic side groups) the highest molecular weights are in the range of 2 million to 10 million. The bonding structure in the backbone is formally represented as a series of alternating single and double bonds. However, this formulation is misleading. Structural measurements suggest that all the bonds along the chain are equal or nearly equal in length, but without the extensive conjugation found in organic polyunsaturated materials. This anomaly will be discussed later. In addition to linear polyphosphazenes with one type of side group, other molecular architectures have also been assembled. These include polyphosphazenes in which two or more different side groups, R1 and R2, are arrayed along the chain in random, regular, or block distributions. Other species exist with short phosphazene branches linked to phosphorus atoms in the main chain. Also available are macromolecules in which carbon or sulfur replace some of the phosphorus atoms in the skeleton. Star-geometry structures, using the symbolism defined, are also accessible. A new and growing area is the field of phosphazene-organic and phosphazene-polysiloxane hybrid linear copolymers, and comb copolymers of the types. In addition, polymers are known in which six-membered phosphazene rings are side groups linked to organic polymers, and where phosphazene rings are linked by organic connector groups to form cyclolinear or cyclomatrix materials.


1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.


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