Miscellaneous Applications

Other applications of polymers are chemical, solvent, chemical and oil resistant parts, sterilisation, medical components, washing machine and dishwasher components, marine protection, aerospace, missiles, aircraft jet engines, helicopter, helicopter blades, gamma radiation resistant parts, sporting gear, glazing, battery cases and solar panels. 

The mechanical properties of importance in critical engineering applications include stiffness, rigidity, impact and impact strength, flexural modulus, elongation and include applications in areas such as gears, piping, automotive under the bonnet applications, aircraft and aerospace engineering power transmissions equipment, structural components and so on. 

Electrical properties include volume resistivity, dielectric strength, arc and tracking resistance. Applications include wire covering, ignition and switching systems, relays. 

Thermal properties include parameters such as expansion coefficient, maximum operating temperature and also involve the thermal stability of polymers when they are exposed to heat either during processing operations such as mouldings and also, during the service life of components. Polymers such as PEI, PSU, PI, PPS and PES all have exceptional thermal properties. 

Some of the types of polymers that have been used for engineering parts and/in engineering applications are shown in Table 1.2. 

The following applications highlight the vastly different ways achiral-chiral LC-LC can be used. Many of these applications involve analytes that are structurally related. These structurally related compounds may be impurities from the synthesis of the analyte of interest using either traditional laboratory or biological methods. Achiral-chiral separations can be useful in separating these related analytes. 

Various chiral lumazines produced from the parent pterins by an enzymatic reaction were separated using achiral-chiral multidimensional LC-LC by Klein et al. (1994). A Ci 8 column and a flavoprotein column were used in the reverse-phase mode to achieve the separation of the threo forms of the lumazines. The flavoprotein column was unable to resolve the erythro forms. 

Mancini et al. (2004) reported the use of achiral-chiral LC-LC to separate the various forms of allethrin. A silica gel column was used to separate the allethrin into cis, trans isomers. Then, the cis or trans peak was switched onto a Chiralcel OJ column to separate the stereoisomers. The other set of isomers was analyzed in a subsequent run on the achiral-chiral system. 

FIGURE 14.5 Separations involving voriconazole (1), its mirror image (2), related diaster-eomers (3), chlorinated impurities (4), and an achiral impurity 5. (a) Achiral separation of compounds 1-5 on an amino column with hexane/ethanol mobile phase (b) Chiral separation of compounds 1-5 on Chiralpak As column with hexane/ethanol mobile phase (c) Achiral-chiral multidimensional separation with the amino and chiral column coupled in series. Reprinted from Ferretti et al. (1998) with permission from Vieweg Verlag. 

Achiral-chiral chromatography has also been accomplished using subcritical fluid chromatography (Phinney et al., 1998). In this work, the structurally related [3-blockers, 1,4-benzodiazepines, and two cold medicines were separated using methanol or ethanol modified carbon dioxide mobile phases. The (3-blockers were separated using cyanopropyl and Chiracel OD columns connected in series. Likewise, an amino bonded phase and Chiracel OD column were used for the separation of the 1,4-benzodiazepines. Guaifenesin and phenylpropanolamine from cough syrup were separated on cyanopropyl and Chiralpak AD columns in series. 

Miscellaneous applications - those that don t exactly fit into the electrieal or mechanical categories - are numerous and sometimes unique to one industry. The following applications are usually encountered in the power generation industry, but also have counterparts in other industries. 

This section will report briefly on a few applications selected to illustrate the scope and diversity of the utility of activated carbon in vapor-phase systems. 

Some valuable applications of gas- and vapor-adsorbing carbons are  

To protect scientific instruments, manuscripts, photographic film in storage. 

Control of volatile toxic vapors in laboratory storage spaces Odor tents in hospitals 

In vents from laboratory hoods to prevent contamination of surroundings Filters for cigarettes Removal of sulfur from synthesis gases Removal of arsenic from hydrogen chloride Gas chromatography Aid in operation of vacuum pumps 

111 forensic laboratories a considerable number of the above methods are in routine use but there are also some applications which are only called upon occasionally. For example, the analyses of sugars, optical bright-eners or explosives may be required and methods have been developed for these analytes. 

The generally accepted method for separating sugars is to use an amino-bonded silica. However, an alternative method, whereby separations are achieved on a silica column dynamically modified with a long chain amine or a polyethylene amine is preferred since this system is far less susceptible to column poisoning . 

Optical brighteners are used to make paper, fibres and other materials whiter and brighter in appearance. These compounds are neutral or ionic and their retention on an HPLC column can be obtained by either reversed phase or ion-pair chromatography. Optical brighteners are naturally highly fluorescent and therefore trace levels can be detected by monitoring the eluate fluorescence. Extreme caution must be taken with 

Finally, HPLC is used for the analyses of explosives and in some forensic laboratories it is being introduced as a routine procedure. Chromatographic separation of explosives can be achieved by reversed-phase chromatography on alkyl-bonded silicas but a major problem has been in finding a technique capable of detecting nanogram quantities of materials. To date, the most sensitive method has been reductive electrochemical detection and provided fairly extensive operational precautions are taken (in particular the exclusion of oxygen), the required detection levels can be achieved. 

HPLC is an important analytical technique in a forensic science laboratory since it can be employed for the analysis of an extensive range of analytes in many varied and complex matrices. The potential of this technique is due to its versatility and through the exploitation of separation and detection methods the desired selectivity and/or sensitivity can be achieved only through the development of new techniques or the modification of existing chromatographic techniques. Future applications will still rely on research work performed in forensic laboratories. This is because of the complex and often diverse nature of casework problems which are rarely encountered in other types of analytical laboratories. 

Preform mouldings are particularly useful in carrying containers and protective covers. Examples of their use include television receiver backs, moulded suitcases and typewriter cases. Although the finish obtained during moulding is frequently adequate in industrial applications some improvement is necessary where a good appearance is desired. Methods used include painting or 

Phenolic resins are useful surface coating materials. Resols are useful for stoving lacquers for coating chemical plant, textile equipment, razor blades, brassware and food cans. Phenolic resins are used with poly(vinyl formal) as a flexible, tough and solvent-resistant wire enamel. Oil-soluble resins based on synthetic phenols form the basis of some gloss paints. 

The resins act as a plasticiser during processing but they cross-link while the rubber is vulcanising to give a harder product with improved oxidation resistance, oil resistance and tensile strength. The addition of sufficient resin will lead to an ebonite-like product. 

Similar products from natural rubber may be made by fluxing a cresol novolak containing hexamine with the rubber at 150°C. 

Other uses include impregnation of wood to improve dimensional stability and reduce water absorption, sealing of porous metal castings by impregnation, and coil impregnation, to give a rigid structure both heat and water resistant. 

The examples above show the wide applicability of non-aqueous SEC to the analysis of low-molecular-mass compounds or materials. The list is by no means exhaustive, and many more examples can be found. Each relies on the simplicity of SEC separation, which sometimes makes the application look almost trivial. However, these simple, development-free applications are quite important in practice. 

Warren [4] showed a determination of warfarin in rodent bait. The bait is of higher molecular mass and is clearly separated from warfarin in a 12-minute analysis on a single Ultrastyragel 100 A column with tetrahydrofuran as solvent. 

The simplicity and speed of SEC separations will ensure that SEC has widespread value in the low-molecular-mass area. The separating power of HPLC and GLC will always be greater, but the combination of techniques with different modes of separation will become more important as flowswitching systems with fully programmable computer-controlled operation become more freely available. Examples have already been highlighted for 

SEC has become a well-established method of separation for components of moderately high molecular mass (MM 500-2000), where GLC and HPLC are less effective or not applicable. The fast-improving method of supercritical fluid chromatography (SFC) will possibly become the most widely used technique in this area (see Chapter 9). A recent paper [56] describes the use of SFC for the analysis of waxes, using mass spectrometry to identify the components. 

The medium-molecular povidones and above all the high-molecular grade, povidone K 90 are used as thickeners in oral and topical solutions and suspensions (viscosity curves, see Section 2.2.3). The use of povidone in suspensions is described in Section 2.4.6. The thickening effect can also be used to adjust the viscosity of solutions - oral drops, eye drops, solutions and syrups - to give a particular drip or flow rate. The thickening effect reduces diffusion processes in the solution, improving the stability of some active substances. 

The good solubility of povidone in different solvents enables them to be used also as thickeners in aqueous/alcoholic preparations. 

Because of their excellent adhesion and physiological safety, povidone K 30 and povidone K 90 are used as adhesives on the skin or mucous membranes. Examples include transdermal systems, oral adhesive gels, buccal adhesive patches or tablets [511,546,547,559,573,574], contact gels for electrocardiograph or electroencephalograph electrodes and adhesives for colostomy bags. Table 107 shows a formulation for a contact gel developed on a laboratory scale for ultrasonic scanning. 

A relatively concentrated, e.g. 20-30%, clear solution of povidone K 90 is adequate as the basis for adhesive gel formulations for application in the mouth or for colostomy bags [375]. 

In transdermal or mucosal systems, povidone, particularly the medium and high-molecular types, can be used as an bioadhesive, to improve or to control transdermal absorption [535, 571, 658], or to stabilize active ingredients or to 

Various liquid chromatographic methods have found application in the control of the synthesis of new dye molecules. Thus, an alkali-clearable azo disperse dye with a fluorosulphonyl group was synthesized and it stability was checked by RP-F1PLC. The synthesis route is depicted in Fig. 3.133. The purity control and the hydrolysis rate of the new dye was followed by RP-F1PLC using an ODS column and an ACN-water (80 20, v/v) 

Some new benzanthrone dyes were synthesized and applied for the one-step colouration and stabilization of polystyrene. The chemical structures of monomeric benzanthrone dye (formula 1), the stabilizer TTMP 2,2-(2,2,6,6-tetramethylpiperidine-l-yl)-4,6-dichloro-l,3,5-triazine (formula 2) and the new synthetic product showing both colouration and stabillizer capacity (formula 3) are shown in Fig. 3.135. The synthesis process was controlled by TLC using a silica stationary phase and an n-heptane-acetone (1 1, v/v) 

4 were diluted to 0.25 mg/ml. Column Nucleosil C18, 5 pm, 4.6X250 mm 20 pi. injection. Solvent programme for Reactive red 2 and Reactive brown 23 5 min isocratic 50 mM ammonium acetate 0-70 per cent methanol linear gradient for 35 min 70-100 per cent methanol for 1 min 5 min isocratic methanol. Solvent programme one for Reactive orange 4 5 min isocratic 50 mM ammonium acetate 0-50 per cent methanol linear gradient for 25 min 70-100 per cent methanol for 1 min  

5 min isocratic methanol. Reprinted with permission from K. E. Van Cott et al. [79]. 

Large quantities of zeolite-containing rock is worked in different countries (including the Federal Republic of Germany in the Eifel region) and is utilized in the manufacture of cements, mortars and lightweight building blocks. In Japan, natural zeolites are used as a filler in paper. 

More recent applications of synthetic zeolites are e.g. in the sector of microbiocidal agents (silver zeolites), as 

The characterization of immobilized invertase was carried out, and the technique was successfully coupled to the catalytic activity determination of immobilized cells [59]. Similarly, the results of this technique were useful in the selection of Trigonopsis variabilis strains for high cephalosporin-transforming activity 

Enzyme thermistors have also found applications in more research-related topics, such as the direct estimation of the intrinsic kinetics of immobilized bio-catalysts [64]. Here, the enzyme thermistor offered a rapid and direct method for the determination of kinetic constants (K , Km and Vm) for immobilized enzymes. For the system being investigated, saccharose and immobilized invertase, the results obtained with the enzyme thermistor and with an independent differential reactor system were in very good correlation, within a flow-rate range of 1 to 1.5 ml/min. 

Determination of ADP and ATP by multiple enzymes in recycling systems pyruvate kinase and hexokinase co-immobilized on aminopropyl CPG, was demonstrated by Kirstein et al. [25]. In addition, a second reactor,with L-lactate dehydrogenase, lactate oxidase, and catalase, was used to increase the sensitivity from 6x 10 5 M with no recycling, to 2 x 10 6 M in the kinase bienzyme reactor, 

The use of an enzyme thermistor as a specific detector for monitoring different enzymes [17,63,45] in the eluents from chromatographic procedures had the advantage of being applicable in optically dense solutions, where spectro-photometric methods fail, and of being able to operate on-line for discrete samples. 

Flygare et al. [40] also used the enzyme thermistor for the control of an affinity purification. Here, lactate dehydrogenase (LDH) was recovered from a solution by binding to a special Sepharose gel (AMT-sepharose). The addition of the gel to the solution was controlled by a PID controller or a desktop computer, according to the amount of unbound LDH detected with the enzyme thermistor. Both systems enabled rapid and accurate assessment of the correct addition of the adsorbent. 

Taking note of the high luminescence quantum yield and long luminescence lifetime of the Tb complex of 264b, along with the demonstration that 

For a general review, see Gutlich, P. Hauser, A. Spiering, A. Angew. Chem., Int. Ed. Engl. 1994, 33, 2024. 

Sakaki, T. Kawahara, Y. Shinkai, S. Tetrahedron Lett. 1992, 33, 2163 Deng, G. Sakaki,T. Nakashima, K. Shinkai, S. Chem. Lett. 1992,1287 Deng, G. Sakaki, T. Shinkai, S. J. Polymer Sci. Part A Polymer Chem. 1993,31,1915 Deng, G. Sakaki, T. Kawahara, Y. Shinkai, S. Supramol. Chem. 1993, 2, 71. 

Pulpoka, B. Asfari, Z. Vicens, J. J. Inclusion Phenom. Mol. Recognit. Chem. 1997, 27, 21. Komori, T. Shinkai, S. Chem. Lett. 1993,1455. 

Kawabata, H. Aoki, M. Murata, K. Shinkai, S. Supramol. Chem. 1993, 2, 33. 

Chitosan and its amino acid derivatives (poly D, L-lactic acid) have been explored as an extracellular matrix-like surface to promote cell adhesion and growth [229]. Four kinds of chitosan-amino acid derivatives were prepared to minimize the carbohydrate moieties of cell matrix glycoproteins. 

From detailed cell cultural studies these chitosan derivatives were shown to promote chondrogenesis. Chitosan nanoparticles are shown to enhance oral bioavailability and intestinal absorption of peptide and protein formulations. By ionotropic gelation of chitosan with tripolyphophate anions insulin-loaded nanoparticles have been prepared [230]. 

The capacity to preconcentrate anions has enabled the use of chitosan and its derivatives in modified electrodes, for application in sensor and biosensor electrochemistry [233]. To facilitate improving water solubility of biologically useful chitosan derivatives, N-methylene phosphonic chitosan has been prepared using a one-step reaction that allowed homogeneous modifications [234]. 

Pelletised and calcined mixtures of orthophosphoric acid and kieselghur (which contain polyphos-phoric acids) are used to catalyse the production of cumene and promote the oligmerisation of propylene (see below). 

High-purity phosphoric acid finds application in medicines, jellies, soft drinks and other food compositions (Section 12.4). 

A by-product (so far of limited use) from the manufacture of H3PO4 by the wet process is phosphogypsum. Extraction of fluorine and uranium is also feasible (Chapter 5.2). 

Phosphate esters, although produced in smaller (but nevertheless considerable) quantities than the inorganics , have very diverse but important applications. Substituted phosphates, particularly phosphonates and thioated derivatives, also have a considerable number of current uses. Prominent among these are in pesticides, heavy metal extraction, oil additives and polymers of various kinds. 

As well as featuring in soil chemistry and biosystems, sodium cations together with various phosphate anions have many industrial involvements, the most important of which are detergent powders, textile bleaching formulations, metal cleaning compositions, metal surface treatments, water softening compositions, phosphate glasses, dietary supplements and medicinal formulations. 

Apart from pure analytical apphcations, HSGC has found wide usage among thermodynamicists for the study of mixed phases where it is used to determine physicochemical data on vapour-solid or vapour-liquid systems (Hachenberg and Schmidt, 1977). Van Boekel and Lindsay (1992) studied the partition of some volatiles of cheese in equilibrium with its 

At first glance HSGC and fats and oils may look incompatible. Despite the fact that the majority of substances related to lipids are involatile, some niches exist where HSGC fits in perfectly. In general, a major weakness of static HSGC - a lack of sensitivity when compared with the dynamic variant - can be overcome by cryofocusing. Such systems are now commercially available. This allows one to present to the gas chromatographic detectors the same vapour mixture as one smells on a sample, except at concentrations which are detectable not only by the human nose but also by the detectors commonly used in GC. 

Anaerobe Laboratory (1977) Anaerobe Laboratory Manual, 4th edn. Anaerobe Laboratory, Virginia Polytechnic Institute and State University, Blacksburg, VA. 

and Young, L. L. (1989) Rapid headspace gas chromatographic method for assessment of oxidative stability of cooked chicken meat. Journal of the Association of Official Analytical Chemists, 72, 277-81. 

Bassette, R. and Ward, G. (1975) Measuring parts per billion of volatile materials in milk. Journal of Dairy Science, 58, 428-9. 

The fire properties of flexible foams continue to receive considerable attention details of suitable fire tests have been collated by the International Isocyanates Institute.One growing trend in the flexible foam area is to use MDI-based products, which have advantages over the more conventional toluene diisocyanate systems of shorter demould times and excellent foam structure. Another area which has attracted some attention is that of light-stable integral skin flexible foams. These can be made by utilizing aliphatic isocyanates, u.v. stabilizers, or barrier coatings.  

The possibility of making automotive tyres by casting or reaction injection moulding has frequently been discussed in the past, and now appears to be approaching reality.  

A growing use for polymeric MDI is as a binder the principal areas of application are in the manufacture of foundry moulds, where the isocyanate binds together the sand or agglomerate, and in the manufacture of chipboard. Recent developments in the latter area include the production of modified MDI that has an acceptable working life as an emulsion in water.  

Finally, although conventional urethane elastomers continue to generate much academic interest, - the number of industrial patents and papers has declined. The field has been covered by a very authoritative review.  

Hu et al. [244] investigate the hydrolytic degradation of PLA/poly(e-aminocaproic acid) (Nylon 6) blends and found that hydrolytic degradation-formed lactic acid catalyzed and accelerated the hydrolytic degradation of Nylon 6. This can be applied to enhance the hydrolytic degradation of polycondensation-formed polymers catalyzed by hydro-nium ions. 

Polylactides, in Y. Doiand A. Steinbiichel (Eds.), Polyesters 3, Biopolymers, Vol. 4, Wiley-VCH, Weinheim, 2002, pp. V/129ff. 

Degradation of poly(lactide)-based biodegradable materials, in L. B. Albertov (Ed.), Polymer Degradation and Stability Research Developments, Nova Science Publishers, New York, 2007, pp. 11-59. 

Degradation of Poly(lactide)-Based Biodegradable Materials, Nova Science Publishers, New York, 2007. 

Christel, P. Chabot, J. Leray, Bioresorbable plastic materials for bone surgery, in G. W. Hasting, P. Ducheyne (Eds.), Macromolecular Materials, CRC Press, Boca Raton, FL, 1984, pp. VI/119ff. 

DTA has also been used in catalytic oxidation studies [32], influence of particle size [33], compatibility studies [34], interfacial polymerisation [35], polymer stabilisation studies [36, 37] and the effect of thermal history [38]. 

2 Complimentary Differential Thermal Analysis-Mass Spectrometry 

For qualitative analysis of polymers, it is not necessary to know the product of the reaction, since identification can be based on temperatures and relative heights at the maximum of several of the more prominent fragments once these have been established for known materials. Additional information about the degradation chemistry can be secured if one chooses peaks characteristic of specific products. 

Polymer samples were placed in a tungsten crucible in a Knudsen cell inlet system of a time-of-flight mass spectrometer. The system was evacuated. Samples were then heated at a linear rate. Spectra were determined at one minute intervals. The thermocouple was welded to a support rod 3 mm below the crucible and was calibrated against 

Thayumanaswamy and V. Rajendran, Journal of Applied Polymer Science, 2004, 93, 3,1305. 

A scheme depicting the binding of the monoclonal anti-phosphoserine antibody to the phosphorylated peptide functionalized CNT membrane is shown in Fig. 9.24. In the presence of alkahne phosphatise, the peptide is dephosphorylated and antibody fails to bind. 

Transport studies were conducted to test the hypothesis that enzyme-catalyzed conversion can modulate ionic diSusional flux through a CNT synthetic membrane. 

9 Applications of Carbon-based Membranes for Separation Purposes 

Phospholization of peptide may also affect the flrrx due to its additiorral negative charge. However, the transport rates of ANS were 1.6, 1.4 and 1.5 mmol/cm per h for the peptide, phosphorylated peptide and dephosphorylated peptide, respectively, indicating that phosphorylation and dephosphorylation has practically no effect on the transport rate. 

In the next section, it is described that such CNT/PS functiorral modtrles have favorable electrochemical properties which lead to serrsitive detection system based on thick-film screen-prirrted electrode. 

Organic Extraction from water CLC column conditions Detector Comments LD Ref 

Aliphatic and aromatic hydrocarbons Solid phase microextraction or methylene chloride extraction Flame ionisation — 1—30ppt [185] 

5 xylenol Diethyl ether — Ether methylated with diazomethane, then GC-MS — [187] 

4-nonyl phenol Phenol derivativised to derivative, cleaned up on silica gel then GC-MS lOOppt [188] 

Semi- or non-volatile chlorinated organic Compounds, hexachloro-butadiene, hexachloro-cyclopentadiene, octa. chlorocyclopentadiene, hexachlorobenzene Extractions performed on homogeniser using hexane, hexane -benzene or hexane -toluene Purge and trap method, recoveries 88-125% 0.1 ppb [189] 

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Miscellaneous Applications. Ben2otrifluoride derivatives have been incorporated into polymers for different appHcations. 2,4-Dichloroben2otrifluoride or 2,3,5,6-tetrafluoroben2otrifluoride [651-80-9] have been condensed with bisphenol A [80-05-7] to give ben2otrifluoride aryl ether semipermeable gas membranes (336,337). 3,5-Diaminoben2otrifluoride [368-53-6] and aromatic dianhydrides form polyimide resins for high temperature composites (qv) and adhesives (qv), as well as in the electronics industry (338,339). 

Miscellaneous Applications. CeUular plastics have been used for display and novelty pieces from their eady development. Polystyrene foam combines ease of fabrication with lightweight, attractive appearance, and low cost to make it a favorite in these uses. PhenoHc foam has its principal use in doral displays. Its abiHty to hold large amounts of water for extended periods is used to preserve cut dowers. CeUular poly(vinyl chloride) is used in toys and athletic goods, where its toughness and ease of fabrication into intricate shapes have been valuable. 

Miscellaneous Applications. PEIs and their derivatives ate used as cementation auxihaties in cmde oil exploration (459), and for breaking cmde oil emulsions (460) in cmde oil extraction. Seed coatings of water-soluble copolymers containing polyethyleneimine have been developed (461). Polyethyleneimine derivatives have positive photoresist properties (462) amidated polyethyleneimines improve the flow properties of cement (463) and with few exceptions, A/-acyla2iddines act as chemical sterilisers for insects (464). 

Other miscellaneous applications of malononitdle are the synthesis of 7,7,8,8-tetracyanoquinodimethane (46) which is a powerful electron acceptor in the formation of charge-transfer complexes which are of interest because of their conductivity of electricity (96), as well as of 2-chloroben2yhdene malononitnle [2698-41-1] (45) also known as CS-gas, which is a safe lachrymatory chemical used for self-defense devices (97). 

Miscellaneous Applications. Polyamides, prepared from polyamines and neodecanoic acid, are used as wash-cycle antistatic agents (qv)... 

It also finds miscellaneous applications in textile and metal coatings and in adhesive formulations. Where it is to be used as a safety glass interleaver, a very pure product is required and this is most conveniently prepared from... 

Compared with nylon 66 fibres, the polyurethane fibres (known as Perlon U) have a tensile strength at the higher end of the range quoted for nylon 66, they are less prone to discolouration in air, are more resistant to acid conditions and they have a lower moisture absorption. On the debit side they are less easy to dye, are hard, wiry and harsh to handle and have too low a softening point for many applications. They are currently of little importance but have found some use in bristles, filler cloths, sieves and a few other miscellaneous applications. 

In the chemical process industry molybdenum has found use as washers and bolts to patch glass-lined vessels used in sulphuric acid and acid environments where nascent hydrogen is produced. Molybdenum thermocouples and valves have also been used in sulphuric acid applications, and molybdenum alloys have been used as reactor linings in plant used for the production of n-butyl chloride by reactions involving hydrochloric and sulphuric acids at temperatures in excess of 170°C. Miscellaneous applications where molybdenum has been used include the liquid phase Zircex hydrochlorination process, the Van Arkel Iodide process for zirconium production and the Metal Hydrides process for the production of super-pure thorium from thorium iodide. 

Lead is produced from both primary (i.e., mined ore) and secondary (i.e., scrap metal and wastes) sources, and is imported by the United States. In 1997, production from primary and secondary sources was 343,000 metric tons and 1.1 million metric tons, respectively (Smith 1998), and imports reached 265,000 metric tons (Larrabee 1998 Smith 1998). Approximately 1.6 million metric tons of lead were consumed in the United States in 1997 (Smith 1998). Of lead used in 1997, 86.9% was used for storage batteries, 7.8% was used in metal products, and 5.3% was used in miscellaneous applications (Smith 1998). Because of the adverse health effects associated with exposure to lead, its use in paints, ceramic products, gasoline additives (now banned), and solder has declined dramatically in recent years. In 1997,... 

There are many miscellaneous applications of explosives which may be mentioned but which do not merit individual description. Such uses are those in agriculture, in the preparation of ditches, the diversion of streams, removal of tree stumps, and the breaking up of subsoil. Demolition of old buildings and chimneys is readily carried out. Underwater wrecks may also be broken up for disposal by special application of explosive charges. 

In this chapter brief information on the origin and cost of titanium will be discussed. A definition of the term unique properties will be given and how these properties are exploited in the membrane, diaphragm and in the mercury cell processes will be considered and miscellaneous applications touched upon. The chapter will conclude with a summary of the financial benefits which, after all, propel the use of this challenging material. 

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