Comparison of X-Ray Diffraction Intensities with Structure Factor Computations in Liquid Long Chain Compounds

Radiology ◽  
1931 ◽  
Vol 16 (3) ◽  
pp. 359-364 ◽  
Author(s):  
Ross D. Spangler
Keyword(s):  
Structure Factor ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chain Compounds ◽  
Long Chain

scholarly journals A further X-ray investigation of long chain compounds (n-hydrocarbon)

1928 ◽  
Vol 120 (785) ◽  
pp. 437-459 ◽  
Keyword(s):  
Crystal Structure ◽  
Stearic Acid ◽  
Single Crystals ◽  
Cross Section ◽  
Structure Factor ◽  
Chain Structure ◽  
Practical Reasons ◽  
X Ray ◽  
Chain Compounds ◽  
Long Chain

In a previous paper the writer has outlined the crystal structure of a number of long-chain compounds. One of the main results of this work was to show that the crystal molecules (chains) in all these substances can be represented as rods of definite cross section, the crystals being built up of bundles of these rods packed close together. A closer examination of the X-ray photographs of stearic acid gave the clue to the chain structure, and led to a general formula for the structure factor. It was then announced that a more detailed investigation of stearic acid was to follow. The choice of stearic acid was dictated entirely by practical reasons, no other well developed crystals of other similar substances being available at that time. But as it was obviously more desirable to study first the prototype of the long chain compounds, namely, the normal hydrocarbon, efforts were first made to find single crystals of these substances. The search was unexpectedly successful, and the present paper describes an attempt to interpret the results of the X-ray examination of a single crystal of the hydrocarbon C 29 H 60 .

x-Ray Diffraction Studies of Built-up Films of Long-Chain Compounds

1935 ◽  
Vol 57 (2) ◽  
pp. 330-331 ◽  
Author(s):  
G. L. Clark ◽  
R. R. Sterrett ◽  
P. W. Leppla
Keyword(s):  
X Ray Diffraction ◽  
X Ray ◽  
Chain Compounds ◽  
Long Chain

The Epicuticle of an Arachnid, Palamneus swammerdami

1954 ◽  
Vol s3-95 (31) ◽  
pp. 371-381
Author(s):  
G. KRISHNAN
Keyword(s):  
Outer Membrane ◽  
Diffraction Pattern ◽  
Basal Layer ◽  
Thin Membrane ◽  
Basic Pattern ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chemical Constitution ◽  
Long Chain

The epicuticle of Palamneus swammerdami in the unhardened condition is homogeneous. It stains uniformly red with Mallory. When hardened, it comprises an internal unstained region, giving evidence of --S--S-- bonding, and is bounded externally by a very thin membrane which stains blue with Mallory. The protein of the inner basal layer differs from its counterpart in the insect epicuticle in the absence of tyrosine, in the occurrence of cystine and cysteine, and in being resistant to the action of hot alkalis. Though apparently related to the keratin of vertebrates, it is not identical with it. The outer thin membrane is lipide in nature. X-ray diffraction studies show that the epicuticular protein is unique: it is unlike both arthropodin and the keratin of vertebrates. However, the outer membrane of the epicuticle yields a diffraction pattern indicating the presence of long-chain paraffins and is similar to the outer epicuticle of the blowfly larva. The chitin of the cuticle appears to be identical in pattern with that of insects. In spite of differences in structural and chemical constitution, the epicuticle of the scorpion shows a resemblance to the basic pattern of the insect epicuticle. The differences may be attributed to the absence of phenolic tanning and the occurrence of --S--S-- bonding. The possible role of the purines present in the cuticle of the scorpion is discussed in relation to --S--S-- bonding.

X-Ray Investigations on Molten Cu-Sb Alloys

1994 ◽  
Vol 49 (4-5) ◽  
pp. 530-534 ◽  
Author(s):  
Th. Halm ◽  
H. Neumann ◽  
W. Hoyer
Keyword(s):  
Electronic Properties ◽  
Structure Factor ◽  
Correlation Functions ◽  
Pair Correlation ◽  
Model Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Factors ◽  
Diffraction Structure ◽  
Eutectic Concentration

Abstract Using X-ray diffraction, structure factors and pair correlation functions of several molten Cu-Sb alloys and pure antimony were determined and compared with published structural, thermodynamic and electronic properties. The eutectic concentration Cu37Sb63 was investigated in dependence on temperature, and a model structure factor was calculated applying a segregation model.

Exfoliated single molecular layers of Mn0.8PS3 and Cd0.8PS3

2005 ◽  
Vol 20 (5) ◽  
pp. 1107-1112 ◽  
Author(s):  
R.F. Frindt ◽  
D. Yang ◽  
P. Westreich
Keyword(s):  
Ion Exchange ◽  
Structure Factor ◽  
Single Layer ◽  
Layered Compounds ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vacancy Ordering ◽  
Diffraction Patterns ◽  
Molecular Layers

The layered compounds MnPS3 and CdPS3 were exfoliated to form single molecular layers of Mn0.8PS3 and Cd0.8PS3 in suspension in water by ion exchange. The x-ray diffraction patterns of the two single-layer suspensions showed profound differences in some of the Bragg peaks, and we demonstrated that the differences are not due to the quality or size of the single layers, but are caused by structure factor modulations of the Warren tail for two-dimensional systems. We also demonstrated that the Cd or Mn vacancies generated in the exfoliation process are not ordered at long range, in contrast to an earlier report of vacancy ordering on intercalated MnPS3.

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