Needs for Improvement

Nylon. Nylons comprise a large family of polyamides with a variety of chemical compositions (234,286,287). They have excellent mechanical properties, as well as abrasion and chemical resistance. However, because of the need for improved performance, many commercial nylon resins are modified by additives so as to improve toughness, heat fabrication, stabiUty, flame retardancy, and other properties. 

Many antioxidants ia these classes are volatile to some extent at elevated temperatures and almost all antioxidants are readily extracted from their vulcanizates by the proper solvent. These disadvantages have become more pronounced as performance requirements for mbber products have been iacreased. Higher operating temperatures and the need for improved oxidation resistance under conditions of repeated extraction have accelerated the search for new techniques for polymer stabilization. Carpet backiag, seals, gaskets, and hose are some examples where high temperatures and/or solvent extraction can combine to deplete a mbber product of its antioxidant and thus lead to its oxidative deterioration faster (38,40). 

The development of polythiophenes since the early 1980s has been extensive. Processible conducting polymers are available and monomer derivathation has extended the range of electronic and electrochemical properties associated with such materials. Problem areas include the need for improved conductivity by monomer manipulation, involving more extensive research using stmcture—activity relationships, and improved synthetic methods for monomers and polymers alike, which are needed to bring the attractive properties of polythiophenes to fmition on the commercial scale. 

To improve magnesium reduction, which also improves siHca reduction in cold process softening, sodium aluminate may be used. The sodium aluminate provides hydroxyl ion (OH ) needed for improved magnesium reduction, without increasing calcium hardness in the treated water. In addition, the hydrolysis of sodium aluminate results in the formation of aluminum hydroxide, which aids in floe formation, sludge blanket conditioning, and siHca reduction. 

Although carbon electrode production has been regarded as a mature business, the steady growth in demand and the need for improved electrodes has prompted ongoing development efforts in these areas (/) cost containment through raw material substitutions and process improvements (2) higher purity electrodes for those processes such as siUcon production (J) improvements in thermal shock resistance to enhance electrode performance and (4) better joining systems for prebakes. 

Maxillofacial polymers include the chlorinated polyethylenes, polyethemrethanes, polysiloxanes (see Elastomers), and conventional acrylic polymers. These are all deficient in a number of critical performance and processing characteristics. It is generally agreed that there is a need for improved maxillofacial polymers that can be conveniently fabricated into a variety of prostheses (218,227,228). 

Decoupled Driving Force and Depolarization Needs for improved fractionation motivate designers to reduce autofiltration. Using fluid velocity for depolarization means that hydrodynamic pressure drop will be additive to the transmembrane pressure driving force. Schemes to hmit this effeci confront a harsh economic reahty. Two novel schemes decouple the driving from the depolarizing force. 

The need for improving and testing temperature effects with exothermic, fast reactions was obvious. 

Determine the policies needed for improvement, i.e. the broad guidelines to enable management to cause or stimulate the improvement. 

Various authors have described on-line LC-SFC coupling [947,948]. Coupling of LC to SFC with conventional-size LC columns, where only a small fraction of the peak of interest is transferred to the SFC, allows only for qualitative results, and does not address the need for improved sensitivity in cSFC. Cortes et al. [948] have described relatively large-volume sample introductions (>10 xL) into cSFC, using microcolumn LC in the first dimension. LVI-LC-cSFC provides enhanced sensitivity compared with conventional cSFC injection techniques. LC-cSFC is expected to be of utility in the characterisation of complex samples, and in the determination of components which are thermally labile do not contain significant chromophores or do not have sufficient volatility to be analysed by GC. 

Enzyme Catalyzed. The enzyme aldolases are the most important catalysts for catalyzing carbon-carbon bond formations in nature.248 A multienzyme system has also been developed for forming C-C bonds.249 Recently, an antibody was developed by Schultz and co-workers that can catalyze the retro-aldol reaction and Henry-type reactions.250 These results demonstrate that antibodies can stabilize the aldol transition state but point to the need for improved strategies for enolate formation under aqueous conditions. 

As time goes on, more and more people are being involved in these types of plant design. Most chemical companies estimate that 50% of their profits 10 years hence will come from products not currently known to their research laboratories. Since these will compete with other products now on the market, there will be a great need for improving present processes and estimating a rival s financial status. 

Synthetic carbonaceous materials are widely used in these applications. Several types of synthetic materials (e.g. graphitized mesophase carbon microbeads (MCMB), graphitized milled carbon fiber, and even, initially, hard carbons) became the materials of choice at the time of commercialization of first successful lithium-ion batteries in late 1980s. New trends, mainly driven by cost reduction and need for improved performance, currently shift focus towards application of natural graphite. 

There is a need for improved modeling tools to accommodate heuristic and qualitative reasoning. 

The need for improved background correction performance has generated considerable interest in applying the Zeeman effect, where the atomic spectral line is split into several polarised components by the application of a magnetic field. With a Zeeman effect instrument background correction is performed at, or very close to, the analyte wavelength without the need for auxiliary light sources. An additional benefit is that double-beam operation is achieved with a very simple optical system. 

This review is timely because of the likely increase in the use of beryllium compounds in the coming years. There is therefore a need for improved knowledge of beryllium chemistry, especially in relation to aqueous solutions. There is little doubt that fear has played a part in the relative underdevelopment of beryllium chemistry now that the hazards are better understood it should be possible to make good progress. 

The need for improved sensor performance has led to the emergence of micro and nanofluidics. These fields seek to develop miniaturized analysis systems that combine the desired attributes in a compact and cost-effective setting. These platforms are commonly labeled as labs-on-chip or micro total analysis systems (pTAS)2, often using optical methods to realize a desired functionality. The preeminent role that optics play has recently led to the notion of optofluidics as an independent field that deals with devices and methods in which optics and fluidics enable each other3. Most of the initial lab-on-chip advances, however, occurred in the area of fluidics, while the optical components continued to consist largely of bulk components such as polarizers, filters, lenses, and objectives. 

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