Further Development

To further improve tolerability, convenience of dosing and therefore compliance, recent development efforts have been focused on alternative delivery systems for contraceptives. These include transdermal, as well as vaginal, and implantable, or injectable systems. [79] 

Finally, control of male fertihty represents also an important option. The ideal reversible contraceptive would induce azoospermia (absence of sperm cells in semen), without influencing a man s libido or sexual potency. The current best prospect for success is the combination of testosterone and a progestin with or without a GnRH-antagonist. This regimen has shown efficient suppression of spermatogenesis and no serious adverse effects. 

From June 2006 to September 2007 further papers appeared dealing with the structural characterization of pyrroles and their benzo derivatives. Only a brief selection is reported here, highlighting those structural studies that focus on simple derivatives of pyrrole and indole. 

The rapidly expanding area of elimination reactions in the field of carbohydrates has led, even in a short time, to many interesting, basic observations. From these results, however, as a further addition to this Chapter, only a few can be discussed. 

Horton and coworkers have described an enol thioacetal-forming, elimination procedure starting from 2,3 4,5-di-0-isopropylidene-n-xylose diphenyl dithioacetal (246) leading to 2-deoxy-4,5-0-isopropylidene-D-tfireo-pent-l-enose diphenyl dithioacetal (247), which is, formally, a carbohydrate ketene derivative. Compound 247, obtained in a yield of 62%, is of potential interest for the preparation of various rare sugars. Treatment with acid converts it into derivatives of heteroaromatic compounds (furans and pyrans). 

Furan derivatives were obtained by Zemlicka and coworkers by using a double )8-elimination procedure starting from nucleoside-5 -uronates. For example, ethyl 2, 3 -di-0-(methylsulfonyl)uridine-uronate 

Saturation of the double bond by hydrogenation, and reduction of the alkoxycarbonyl group by means of complex, metal hydrides, led to various new deoxynucleotide analogs. 

The 6-aldehyde derivatives of 4,5-unsaturated 4-deoxyhexopyranosides, which can be obtained by a photochemical route according to the method of Horton and coworkers, have proved to be useful starting-materials for the preparation of higher-carbon sugars. Horton and Liav have 

The firework mentality also decreed that even if the range was achievable, in order for an unguided rocket to follow a rainbow trajectory across the English Channel and fall, under gravity, onto London, the launch angle would have to be impossibly precise - about half a degree from the vertical, in fact. 

Both arguments were flawed, of course, and Allied Intelligence later showed that the 14 ton V2 rocket bomb was in fact powered with liquid propellant, was guided using gyroscopes, and did indeed carry one ton of explosive. And on the 3rd September 1944 the first V2 fell on London. Some firework  

Perhaps the most extreme gunpowder rockets are the Japanese Ascending Dragon or RYUSEI Skyrockets which are launched in Japan on 10th October in celebration of Health Sports Day. 

The largest RYUSEI rocket is said to be 18 m in length and weighs around 40 kg (sic). Built in three sections the head or payload section holds sequential fireworks and smoke dragons attached externally, while the combustion chamber is made from split pine logs, gouged out and then re-assembled to make a cylinder. 

Up to 5 kg of gunpowder mixture comprising saltpetre (10) charcoal (2) and sulfur (1) is packed into the pine cylinder where a blasting hole (nozzle) is bored at the bottom of the cylinder. 

In the schematic the detector coil (hatched boxes) and its associated field lines are shown (dotted) and are seen to be always orthogonal to the permanent magnet field lines (solid). The magnitude of the static field is constant in the horizontal plane (thick black line). A stepper motor and gear-drives for raising the whole assembly relative to the external surface are visible in the photograph. 

GARField has found a niche application area in the characterization of drying and film forming from aqueous dispersions and in skin-care. As a bench-top perma- 

thank The UK Engineering and Physical Sciences Research Council, The European Commission, The Royal Society, ICI Paints, Unilever Research, Uniqema and Disperse Technologies for financial support. They acknowledge the considerable input and help of their colleagues, especially Dr. Paul Glover (University of Nottingham), Dr. Joe Keddie (University of Surrey) and Dr. Peter Aptaker (Laplacian Ltd.) in carrying out much of the work reviewed here. 

McDonald 1997, Prog. Nucl. Magn. Reson. Spectroso. 30, 69-99. 

Callaghan 1991, Principles of Nuclear Magnetic Resonance Microscopy, Clarendon Press, Oxford. 

Another example in the C-glycosylated, unsaturated hydrocarbon series is methyl 2-deoxy-3,4-0-isopropylidene-2-C-methylene-/3-D-erythro-pentopyranoside (213), obtained90 in 55% yield by the reaction of methyl 3,4-0-isopropylidene-/3-D-eryfhro-pentopyranosid-2-ulose (212) with methylenetriphenylphosphorane n-butyllithium was used as a proton acceptor. Subsequent reduction of 213 with 10% palladium-on-charcoal led to a 7 1 mixture of the 2-epimeric methyl 2-deoxy-2-C-methylpentopyranosides (214 and 215, respectively). In the n.m.r. spectrum of 214, the H-l resonance appeared as a doublet at r 5.62 p.p.m., exhibiting aJia coupling constant of 8 Hz, thus indicating H-2 to be axial and, therefore, the D con- 

The synthesis of 6,7-dideoxy-l,2 3,4-di-0-isopropylidene-a-D-gafricfo-hept-6-enopyranose (216), starting from l,2 3,4-di-0-iso-propylidene-a-D-gaZacfo-hexodialdo-l,5-pyranose (25) with subsequent addition of diethoxymethylsilane to form 6,7-dideoxy-l,2 3,4-di-0-isopropylidene-7-(diethoxymethyIsilyI)-a-D-ga/acto-heptopyranose (217), has also been reported.91 

The interaction of the aldehydo derivatives 14a, 14b, and 55 with methylenetriphenylphosphorane has been re-investigated92 with the use of a 1 1 potassium terf-butoxide-fert-butanol complex in the reaction mixture. This modification affords significantly increased yields of the final alkenes (15a, 15b, and their 3-O-benzyl analogs). 

In further research on the carbon-chain extension of monosaccharides by reaction of free sugars with (alkoxycarbonylmethylene)-triphenylphosphoranes, Kochetkov and coworkers have reported93 

By utilizing the tendency of 1,3-dibromoacetone to undergo monosubstitution upon reaction with triphenylphosphine, Zhdanov and Uslova have synthesized96 (bromoacetylmethylene)triphenylphos- 

Recent findings have shown that the certified value of TBT in the CRM 462 has decreased by ca. 20% over a long-term period (36 months storage at +4°C). This has justified that the material be withdrawn from the market and that a new homogeneity and stability study be undertaken. A re-certification of DBT and TBT in CRM 462 has been conducted in 1997 by the IRMM. The results show that materials certified for their butyltin contents should imperatively be stored at -20°C in the dark. The new certified values are (54 15) pg kg as TBT and (68 12) pg kg as DBT [14]. 

A complementary project has started in 1997 by an interlaboratory study on butyl-and phenyl-tin compounds in a freshwater sediment reference material. A certification campaign has been conducted in 1998 and the certification of the six compounds (mono-, di- and tri-butyl and phenyltins) is promising [15]. All precautions have been taken to ensure the material stability (storage at -20°C). 

The optimal stabilisation procedure (by gamma-irradiation) investigated on the test material in the interlaboratory study [17] was used on the candidate CRM. The optimal gamma-ray irradiation dose was found to be 8 kGy upon which the sterilisation of the sediment was achieved without affecting the methylmercury content [17,19). 

The stability of the material was tested at -80°C, +20 C and +40°C, respectively, over a period of 15 months and total mercury and methylmercury were determined at regular intervals during the storage period. No instability of the material could be demonstrated. 

A brief description of the methods used is given in Table 9.5 additional details on these methods may be found in the certification report [19]. 

Because of their salt-like structure, the quaternary ammonium salts enable a selective continuous separation of phosphine oxides and degradation products during the hydroformylation reaction and thus a prolongation of catalyst life-time [38]. The amine backbone can be re-used. The finally recovery of valuable metal, anions, or cations is possible by simple neutralization reactions. 

Additionally, other types of ligands could be used which have the right molecular mass to make possible sufficient retention in the subsequent membrane separation step. 

Having learned that much about the kinetics and mechanisms of homogeneous hydrogenations in the past 60 or so years, is there anything special in hydrogenations in aqueous systems The answer is yes, and it lies in the distinct properties of water as contrasted with those of non-aqueous (mostly, but not exclusively, organic) solvents (cf. Sections 2.2 and 2.3). 

A specific value of water as solvent lies in the fact that there are catalysts (such as K3[Co(CN)5]) and substrates (e.g., carbohydrates) which do not dissolve in common nonpolar organic solvents. In the special cases of hydrogenations in living systems, although the constituent lipids are soluble in organic solvents, use of an aqueous medium is essential to preserve the integrity of the cell membranes (cf. Section 6.15). 

Aqueous-Phase Organometallic Catalysis, Second Edition 

Here it is my purpose simply to point out the directions that UNF chemistry took following the period covered by this review. Two major discoveries had great influence. The first was the demonstration, by genetic techniques, that alternative nitrogenases existed in which molybdenum is replaced by vanadium or iron. This led to renewed interest in producing ammonia from iron 

Chatt and R. L. Richards, in The Chemistry and Biochemistry of Nitrogen Fixation, ed. J. R. Postgate, Plenum Press, London, 1971, p. 19. 

Tominari, Y. Ushida and A. Misono, J. Chem. Soc., Chem. Commun., 1969,1392. 

Richards, in New Trends in the Chemistry of Nitrogen Fixation, eds. J. Chatt, L. M. da Camara Pina and R. L. Richards, Academic Press, London, 1980, p. 199. 

Richards in Biological Nitrogen Fixation for the 21st Century, eds. C. Elmerich, A. Kondorosi and W. E. Newton, Kluwer, 1998, p. 17. 

Elemental fractionation (e.g., boiling) alters both the He/ °Ar and the Her Ar values and, since the °Ar/ Ar value remains unchanged, results in horizontal movement from the plane. 

Pb-Zn deposit, Colorado mineral belt (Thrower 1999). Early stage samples formed from a magmatic fluid with He/ He of 4.1 Ra and ASW ( Ar/ °Ar = 0.0034). Continued addition of a crustal component during deposition further lowered the He/ He to 

CJB thanks Keith O Nions, Alex Halliday, Max Coleman, Barbara Sherwood Collar and Martin Schoell for their inspiration, support and collaboration in this field. RB thanks Clint Thrower, Mark Kendrick, Pete Bumard, Grenville Turner and Richard Pattrick for assistance and discussions. BM thanks Daniele Pinti, Max Coleman, Jean-Michel Matray, Christian Fouillac, Richard Worden and Frederique Walgenwitz for support and collaboration over five years and more. We thank Zhou Zheng for many useful comments, Don Porcelli for his detailed review and editorial handling, and Richard Hartley for drafting many of the figures. 

Andrews JN (1983) Dissolved radioelements and inert gases in geothermal investigations. Geothermics 12 67-82 

Andrews JN, Lee DJ (1979) Inert gases in groundwater from the Butter sandstone of England as indicators of age and trends. J Hydrol 41 233-252 

Koemer, Younathan, and Wander have provided additional evidence for the j8 configuration of 2,3 4,5-di-0-benzylidene-)8-D-fi ictopyranose (93). The p.m.r. spectrum of 9.3 in carbon tetrachloride solution was measured at 100 MHz and 35 before and after serial additions of a saturated solution of tris [2,2,6,6-tetramethyl-3,5-heptanedionato] europium (III) in carbon tetrachloride. Apparently, this reagent coordinates selectively with 0-1, because a two-proton 

Department of Chemistry, University of Montreal, Montreal, Quebec, Canada 

The following five Tables are complementary to the Chapter entitled Deoxy Sugars by Stephen Hanessian, Advan. Carbohyd. Chem., 21, 143 (1966). 

Where a deoxy sugar or its derivative has been characterized in more than one publication, the reference number printed in bold type indicates the publication from which the physical constants were taken. The specific optical rotations recorded in the Tables are equilibrium values for those compounds for which mutarotation values have been reported. The abbreviations used to indicate the rotation solvent are as follows A, acetone C, chloroform D, p-dioxane E, ethanol M, methanol P, pyridine W, water. 

Heptoses and octoses M.p x [ ]d degrees Rotation Solvent References 

The development of new chiral phases for preparative use is still an important topic even though more than a hundred phases are commercially available (recent review in Lammerhofer, 2010). The main features to be still improved are selectivity, capacity, and mechanical as well as chemical stability, especially against a wide variety of different solvents. Optimization of the selectivity for chromatographic phases is necessary only up to a certain value. Process SMB applications are usually operated with selectivities between 1.3 and 2.0. Using too high a selectivity results in high eluent consumption needed to desorb the extract compound from the stationary phase. Conversely, phases with much higher selectivities would make it possible to use easy adsorption/desorption procedures. 

The increase in capacity should always be combined with a high chemical stability against a wide variety of different solvents. The high capacities of chiral stationary phases can be used to their full extent only if a good solubility of the racemate can be found. 

A third field of improvement would be the development of chiral stationary phases that combine a low pressure drop with a good efficiency and stability, for example, the pressure stability requirements for the SMB systems could be 

CSP Application range Solvent use Loadability (mg g- CSP) Stability, restrictions for use Availability ( 101 ) 

Cellulose-fibres CTA, CTB Broad Alkanes, alcohols, water 10-100 Good, large column packing difficult Yes 

An extended description of tlie luacroinoleciile solution in term.s of tli magnetic analogy is given by Nikoniarov and Obukhov (1981). 

It should be noted that the same limiting dependences of characteristic values (see Table 4.1) in the form of scaling relationships are led to by sezding transforms of the 

I or t.h( scattered light intensity, this analysis uses a dependence of the Equation 89 type. Turning to the Hdwards-type continuous Gaussian chains will play a part in a further development of polymer theory. 

Dayantis (1982) has iiicude an interesting correlation of the above considered theories and approaches (mean field of Flory-Huggins, corresponding states, and scaling) in the phase separation region. 

State cf/agramr polymer+low molecuhr weight liquid 

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The results of measurements and comparisons of the different magnetic field are presented and discussed. Further development will be shown, that this theory can be applied to solve inverse eddy-current problems as well. 

The equation system of eq.(6) can be used to find the input signal (for example a crack) corresponding to a measured output and a known impulse response of a system as well. This way gives a possibility to solve different inverse problems of the non-destructive eddy-current testing. Further developments will be shown the solving of eq.(6) by special numerical operations, like Gauss-Seidel-Method [4]. 

In conclusion it should be noted that Ukraine has considerable scientific and engineering potential for further development of the NDT TD methods, their more extensive introduction into production. 

Before applying this method to routine testing of critical parts like turbine disks, it has to be further developed and its limitations have to be checked carefully. 

A. Further Development of the Thermodynamic Treatment of the Surface Region... 

JChemPaint is a chemical structure drawing applet. The noteworthy characteristic of this 2D molecule editor is that it is an open source program [208]. This means that the software and the source code of the program are freely available. Every programmer or interested person can participate and enter individual special requests for further development of the application. 

Another successor to OCCS was SECS [35], which was further developed into the GASP system by a consortium of German and Swiss chemical companies. The development of both the CASP and the SECS systems was discontinued in the early 1990. 

This is the basis of their use as ion exchange resins. The resin can be regenerated by treatment with dilute acids. Further developments have... 

This salt turned out to be remarkably stable and a powerful, convenient nitrating agent for a wide variety of aromatics (and later also aliphatics). Over the years, this chemistry was further developed, and nitronium tetrafluoroborate is still a widely used commercially available nitrating agent. 

As I mentioned, USC provided some start-up funds for the Institute. Further development and operation, however, was only possible... 

Once I had decided on a career in chemistry, I was determined rather single-mindedly to make a success of it. I sometimes think about what would have happened had I chosen a different occupation or field. Having a rather competitive nature, I could probably have done reasonably well in a number of other areas. Certainly for some fields you must be born with a special talent. Musical talent, artistic ability, business acumen, leadership ability, and vision can be further developed. 

Further development How would you make TM 413 using the alkyl bromide you have just made This molecule is obviously on the way to a steroid and you can read more about it in Helv. Chim. Acta.. 1947, 3 1422 and J. Amer. Chem. Soc.. 1942, 974. 

Before attempting further development of Eq. (10.33), it is useful to examine the dimensions of the various terms in that expression in SI units ... 

Most aquaculture faciUties release water constandy or periodically into the environment without passing it through a municipal sewage treatment plant. The effects of those efduents on natural systems have become a subject of intense scmtiny in recent years and have, in some instances, resulted in opposition to further development of aquaculture faciUties in some locales. There have even been demands that some existing operations should be shut down. 

Acetylation of acetaldehyde to ethyUdene diacetate [542-10-9], a precursor of vinyl acetate, has long been known (7), but the condensation of formaldehyde [50-00-0] and acetic acid vapors to furnish acryflc acid [97-10-7] is more recent (30). These reactions consume relatively more energy than other routes for manufacturing vinyl acetate or acryflc acid, and thus are not likely to be further developed. Vapor-phase methanol—methyl acetate oxidation using simultaneous condensation to yield methyl acrylate is still being developed (28). A vanadium—titania phosphate catalyst is employed in that process. 

Acetaldehyde oxidation to anhydride does not consume great amounts of energy. The strongly exothermic reaction actually furnishes energy and the process is widely used in Europe. Acetaldehyde must be prepared from either acetylene or ethylene. Unfortunately, use of these raw materials cancels the other advantages of this route. Further development of more efficient acetaldehyde oxidation as weU as less expensive materials of constmction would make that process more favorable. 

Precipitators are currently used for high collection efficiency on fine particles. The use of electric discharge to suppress smoke was suggested in 1828. The principle was rediscovered in 1850, and independently in 1886 and attempts were made to apply it commercially at the Dee Bank Lead Works in Great Britain. The installation was not considered a success, probably because of the cmde electrostatic generators of the day. No further developments occurred until 1906 when Frederick Gardiner Cottrell at the University of California revived interest (U.S. Pat. 895,729) in 1908. The first practical demonstration of a Cottrell precipitator occurred in a contact sulfuric acid plant at the Du Pont Hercules Works, Pinole, California, about 1907. A second installation was made at Vallejo Junction, California, for the Selby Smelting and Lead Company. 

The trend in the use of deep bed filters in water treatment is to eliminate conventional flocculators and sedimentation tanks, and to employ the filter as a flocculation reactor for direct filtration of low turbidity waters. The constraints of batch operation can be removed by using one of the available continuous filters which provide continuous backwashing of a portion of the medium. Such systems include moving bed filters, radial flow filters, or traveling backwash filters. Further development of continuous deep bed filters is likely. Besides clarification of Hquids, which is the most frequent use, deep bed filters can also be used to concentrate soflds into a much smaller volume of backwash, or even to wash the soflds by using a different Hquid for the backwash. Deep bed filtration has a much more limited use in the chemical industry than cake filtration (see Water, Industrial water treatment Water, Municipal WATERTREATiffiNT Water Water, pollution and Water, reuse). 

Horizontal Rotating Pan Filters. These filters (Fig. 10) represent a further development of the tipping pan filter for continuous operation. They consist of a circular pan rotating around the central filter valve. The pan is divided into wedge-shaped sections covered with the filter medium. Vacuum is appHed from below. Each section is provided with a drainage pipe which connects to a rotary filter valve of the same type as in dmm filters. 

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