Cone studies

Graphite was tised as substrate for the deposition of carbon vapor. Prior to the tube and cone studies, this substrate was studied by us carefully by STM because it may exhibit anomalotis behavior w ith unusual periodic surface structures[9,10]. In particular, the cluster-substrate interaction w as investigated IJ. At low submonolayer coverages, small clusters and islands are observed. These tend to have linear struc-tures[12j. Much higher coverages are required for the synthesis of nanotubes and nanocones. In addition, the carbon vapor has to be very hot, typically >3000°C. We note that the production of nanotubes by arc discharge occurs also at an intense heat (of the plasma in the arc) of >3000°C. 

Chappelear, J.E., and Nolen, J.S., "Second Comparative Project A Three Phase Coning Study", Journal of Petroleum Technology, 345-353, March (1986). 

The systems of such type have been developed of all last 10 years. We shall bring some characteristics of one of the last development within the framework of European BRITE project, carried out in LETT This 3D cone-beam tomograph is referred to as EVA Bench or Equipment for Voludensimetry Analysis. It is oriented on NDT of industrial products from ceramics and other composites. One of the main task of this tomograph is achievement of high resolution at study of whole internal volume of researched object. For test sample of the size 10mm spatial resolution in 50mm was obtained [14]. 

For the maximum use of advantages of a cone beam at collecting of data, it is necessary to study and develop effective algorithms of reconstmction for cone-beam projection data. The theory of reconstruction in cone beams is referred to as cone-beam tomography. It had developments in papers of many researchers. ... 

Chang C-C and Winograd N 1989 Shadow-cone-enhanced secondary-ion mass-spectrometry studies of Ag(110) Rhys. Rev. B 39 3467... 

A number of chemiluminescent reactions have been studied by producing key reactants through pulsed electric discharge, by microwave dissociation, or by observing the reactions of atoms and free radicals produced in the inner cone of a laminar flame as they diffuse into the flame s cool outer cone (182,183). These are either combination reactions or atom-transfer reactions involving transfer of chlorine (184) or oxygen atoms (181,185—187), the latter giving excited oxides. 

Hollow Sprays. Most atomizers that impart swid to the Hquid tend to produce a cone-shaped hoUow spray. Although swid atomizers can produce varying degrees of hoUowness in the spray pattern, they aU seem to exhibit similar spray dynamic features. For example, detailed measurements made with simplex, duplex, dual-orifice, and pure airblast atomizers show similar dynamic stmctures in radial distributions of mean droplet diameter, velocity, and Hquid volume flux. Extensive studies have been made (30,31) on the spray dynamics associated with pressure swid atomizers. Based on these studies, some common features were observed. Test results obtained from a pressure swid atomizer spray could be used to iUustrate typical dynamic stmctures in hoUow sprays. The measurements were made using a phase Doppler spray analyzer. 

Rapp (1961) has confirmed this equation in a study of the oxidation in air of Ag-In alloys at 550°C. The reaction proceeds with tire internal formation of In203 particles over a range of indium concenuations, but at a critical mole fraction of indium in the alloy, external oxidation occurs with the growdr of a layer of In203 covering the alloy. The n airsitioir from internal to external oxidation was found by Rapp to occur at the mole fraction of indium cone-sponding to... 

The addition of solid Ba2Xe06 to cold cone H2SO4 produces the second known oxide of xenon, Xe04. This is an explosively unstable gas which may be condensed in a liquid nitrogen trap. The solid tends to detonate when melted but small sublimed crystals have been shown to melt sharply at —35.9°C. Xe04 has only been incompletely studied, but electron diffraction and infrared evidence show the molecule to be tetrahedral. 

Of interest in this connection is a study of the UV spectra of chal-cones of the general type A——CO—where A and B are 2-thienyl, 2-furyl, and phenyl in all combinations. The 2-thienyl group causes a bathochromic shift in both the A- and B-positions,... 

Cone RD (2006) Studies on the physiological functions of the melanocortin system. EndocrRev 27 736-749... 

It is prepd by the action of methylamine on 4-chloro-l-nitrobenzene (Ref 5) by the action of methyl iodide (Ref 6), or methyl sulfate on 4-nit roaniline (Ref 7) or by the hydrolysis of 4-nitro-N-methylformanilide with hot coned aq HC1 (Ref 8). In a study of the effect of nitric acid concn on the prods of the nitration of N,N-dimethylaniline to form Tetryl, it was isolated in low yield by the action of nitric acid, d 1.046g/cc, plus Na nitrite on N,N-dimethylaniline (Ref 10). A eutectic mixt with N-ethyl-4-nitroaniline has been patented as a stabilizer for NC (Ref 12). Studies at NPF indicate that 4-nitro-N-methyl-aniline is superior to Centralite, 2-nitrodiphenyl-amine, or Acardite in stabilizing. NC Refs 1) Beil 12, 586, (295) 1125 ... 

A three-step nitration process of toluene is described. The advantages of the modified process are reduced waste, less hazardous operation, reduced oleum requirement, partial replacement of coned HN03 with dil HN03, and higher rate of toluene flow into the reactor (Ref 86) The continuous process of H.C. Prime (Ref 73) for preparing TNT was studied by thin-layer chromatography on silica gel with a starch binder and a fluorescent indicator. The nitration... 

Hydrolysis of PETN in coned nitric acid solns was studied by Camera Mauro (Ref 63)... 

The general mechanism of nitrating alcohols to form nitrate esters is described under Nitration in this Vol. Several specific remarks about PETN are contained in that article. The industrial nitration of PE differs from most nitrate esters in that it employs coned nitric acid rather than mixed acid. Nevertheless nitration via the nitronium ion mechanism, which is the preferred mechanism in mixed acid nitrations, is also feasible in coned nitric acid. However, Eremenko and co-workers claim that the nitrating agent in PE nitrations, in mixed acid, is unionized nitric acid (Refs 39 76). The present writer does not find Eremenko s arguments to be very convincing. In any case, commercial production of PETN employs nitric acid and not the mixed acids of Eremenko s studies... 

Beyer (B8) has recently reported experimental data obtained in small test motors under atmospheric and altitude conditions. At atmospheric pressure, his results showed the observed ignition delay to be a function of the delivery rate, as shown in Fig. 10. Additional data obtained in small test motors by Fullman and Nielsen (F6) are shown for comparison. These latter investigators conducted studies on the effects of various injectors, with delivery from both the head end and the aft end. Their results indicate that the hollow-cone injector is the most efficient. This subject has been treated in more detail by Miller (M7). 

With a fixed amino acid concentration of 0.02 M, the rate constant proved independent of the concentration of BrO" over the range (0.38-3.09) x 10"3M for N-Br-aminoisobutyric acid and N-Br-Proline. The plot of the obtained initial absorbance values against the initial N-Br-amino acid cone tration shows that Beer s law is obeyed, and the values for the molar absorptivity of the studied N-bromoamino acids are listed in Table 2. 

Several studies have been made of the directionality of approach by the nucleophile. ° Menger ° has proposed for reactions in general, and specifically for those hat proceed by the tetrahedral mechanism, that there is no single definable preferred transition state, but rather a cone of trajectories. All approaches within this cone lead to reaction at comparable rates it is only when the approach comes outside of the cone that the rate falls. 

Further experimental work involving cone voltage studies may provide further confirmatory evidence but the most likely explanation is that the mass spectrum of the component with retention time 4.65 min is that shown in Figure 3.17, while the mass spectrum of the second component is that obtained by background subtraction, and is shown in Figure 3.22. 

---