Recent Trends

Recent trends in the paper industry have had an impact on starch supplies. The implementation of statistical process control has led to more awareness that the production of high-quality paper grades depends on the use of high-quality materials. As a consequence, there is increased emphasis on acceptance specifications for starch supplies according to ISO guidelines and more rigorous testing in order to ensure consistently uniform quality. 

A previous trend in the paper industry of limiting starch purchases to unmodified grades and effecting modification on-site in the paper mill has changed. The variance in products thus obtained was frequently wider than in products supplied by the starch manufacturer. As a result, there is now more preference to utilize modified starches with specific application properties. Growth in paper recycling should lead to an increased use of starch as a coating binder in place of synthetic materials. 

New starch products might be derived from emulsion copolymerization with synthetic monomers and the replacement of all-synthetic polymers. Potential applications could be in flocculation, sizing, modified rheological characteristics, bonding to a wide range of substrates, film formation and in effluent treatment. A critical requirement will be the removal of hazardous residuals and Food and Drug Administration (FDA) approval for use in specific paper grades. 

Introduction of new starch products will require extensive technical services, especially for adaptation to closed paper machine wet-end systems, for use with deinked pulp and for the high shear conditions of high-speed paper coating.46 

In Europe, the main area for development of inhibitors for DB and CMDB propellants is polyurethane-based inhibitors because these inhibitors do not produce smoke or gases which are likely to interfere with vision for remote guidance of guided tactical rockets. 

Thermodynamics has long been regarded as a difficult subject but it is so fundamental to chemistry that it is now taught at all levels. For example. 

It might also have been thought that the scope of application of classical thermodynamics is well understood, but a recent controversy shows that areas of serious argument still exist. The controversy continues but the present position in this discussion of energetics of biological systems can be summarized briefly. Phosphorylation is one of the most fundamental processes occurring in living tissue, and Lipmann divided bio- 

A controversy in relativistic thermodynamics appears to have recently been largely resolved by Hamity. This subject is perhaps of only marginal interest to chemists but concerns such interesting topics as whether the effective temperature of a rapidly moving body is lower than the temperature noted by a co-mover observer or not. 

It is regrettable that, in the past, different symbols have been adopted in compilations, but it is expected that, in the future, symbols advocated by I UP AC will be employed universally and that SI will be used for the units. To secure a further unification in thermodynamic tables, the International Council of Scientific Unions (ICSU) and the Committee on Data for Science and Technology (CODATA) set up in 1968 a Task Group on Key Values for Thermodynamics. The first objective of the Task Group is to prepare a set of values of the basic thermodynamic properties of a number of chemical species, to be agreed internationally. The set is to include the elements in both standard and monatomic gaseous states, aqueous ions, and simple compounds.  

When these values or slight modifications to them have been internationally agreed, it is hoped that they will be applied generally, so that 

---

Mashima K, Nakayama Y and Nakamura A 1997 Recent trends in polymerization of a-olefins catalyzed by organometallic complexes of early transition metals Adv. Polym. Sc/. 133 1-54... 

In 1988 diaphragm cells accounted for 76% of all U.S. chlorine production, mercury cells for 17%, membrane cells for 5%, and all other production methods for 2%. Corresponding statistics for Canadian production are diaphragm cells, 81% mercury cells, 15% and membrane cells, 4% (5). for a number of reasons, including concerns over mercury pollution, recent trends are away from mercury cell production toward the more environmentally acceptable membrane cells, which also produce higher quality product and have favorable economics. 

Detergents may be produced by the chemical reaction of fats and fatty acids with polar materials such as sulfuric or phosphoric acid or ethylene oxide. Detergents emulsify oil and grease because of their abiUty to reduce the surface tension and contact angle of water as well as the interfacial tension between water and oil. Recent trends in detergents have been to lower phosphate content to prevent eutrification of lakes when detergents are disposed of in municipal waste. 

Most coal-tar chemicals are recovered from coproduct coke ovens. Since the primary product of the ovens is metallurgical coke, production of coal chemicals from this source is highly dependent on the level of activity in the steel industry. In past years most large coke producers operated thein own coproduct recovery processes. Because of the decline in the domestic steel industry, the recent trend is for independent refiners to coUect cmde coal tars and light oils from several producers and then separate the marketable products. 

A. Keerkenaar, in R. A. Fromtiing, ed.. Recent Trends in the Discovey, Development and Evaluation of Antifungal Agents, J. R. Prouse, Science PubHshers, Barcelona, Spain, 1987, p. 523. 

A recent trend in particle analysis has been the introduction of personal computer-based automation (3). Sophisticated software packages can be used to automate and speed up the analysis. In some cases these computers can even carry out continuous process control (qv) (see Computer technology). The latest machines also allow the measurements of smaller particles and can detect a wider range of sizes. Machines based on light-scattering principles are being more widely accepted by the industry because of speed. An average analysis takes from 1—2 min, whereas those based on sedimentation principles require from 10—120 min. 

Quinonoid compounds have been thoroughly reviewed (4,6). More recent trends in quinone addition and substitution chemistry were reviewed in 1993 (7). The quinone system in natural products has also been covered (8) there has been a fascinating discussion of the quinone problem (9). 

M. S. Murphy, in Recent Trends in Biotechnology, C. Ayyanna, ed., Tata McGtaw-Hih, New Delhi, India, 1993, pp. 475—80. 

A recent trend in the baking industry is to produce bakery foods with either no or reduced fat, to achieve perceived nutritional benefits (25). The functions of fat are achieved, to a degree, with materials such as maltodextrins and modified starches in combination with gums and emulsifiers (see Fat replacers). 

Peptide Synthesis. The literature on the enzymatic synthesis of peptides is enormous (120—124). Here the basic principles that govern peptide synthesis are illustrated and recent trends in this area reviewed. 

Chhabildas, L.C. (1992), Hypervelocity Launch Capabilities to over 10 km/s, in Recent Trends in High Pressure Research (edited by A.K. Singh), Oxford Publications, New Delhi, pp. 739-746. 

Recent Trends in U.S. Electric Utility DSM Spending (Billion )... 

A recent trend is the development of park and ride areas for transit passengers to drive to transit. These facilities help make transit accessible to a wide geographic area. Because emissions control devices are ineffective when cold, the auto trip to the transit station may produce nearly as many pollutants as a direct trip to the final destination. Further, park and ride lots occupy a lot of space, making transit stations... 

Recent trends in protective coatings used on buried pipelines have been away from reinforced hot applied coal tar and asphalt enamels and butyl rubber laminate tapes, particularly where applied over-the-ditch . The more recently developed coatings based on fusion bonded epoxies, extruded poly-ethylenes, liquid-applied epoxies and polyurethanes, require factory application where superior levels of pipe preparation and quality control of the application process can be achieved. 

Recent trends are away from rinses containing Cr(vi) and more towards those containing Cr(iii) for health and safety reasons. 

One of the major drawbacks to many promising copolymers is their unsatisfactory electrochemical stability. Carbonyl groups which feature in many of the back-bone/chain linking groups are likely to cause stability concerns. Likewise, urethane, alcohol, and siloxane functions are sensitive to lithium metal. With this in mind, a recent trend has been to find synthetic routes to amorphous structures with... 

Recent trends in rocket propint development and most of the recent developments in SP are for rocket and not gun proplnts, were directed toward the attainment of higher energy systems (actually higher specific impulse). Unfortunately, the use of exotic components presents grave stability problems which are yet to be overcome. Some energetic plasticizers have been developed and in some applications specific impulse has been increased substantially by substituting Be for Al. Much of this subject remains classified... 

The synthesis and properties of PQ and PPQ have been previously reviewed,17,160 and this section will discuss mainly the recent trends in synthesis. 

Due to their favorable solubility, alkanesulfonates are preferred as surfactants in liquid products and concentrates. The recent trend to renewable resources has led to a somewhat reduced use in formulations of household detergents in past years. While some manufacturers have withdrawn these surfactants from, for example, manual dishwashing detergents, others did not. Besides many other industrial applications, alkanesulfonates are one of the most important emulsifiers in vinyl polymerization. 

An important recent trend is the tendency for the two processes, CVD andPVD, to merge. For instance, CVD now makes extensive use of plasma (a physical phenomenon) and reactive PVD (evaporation or sputtering) occurs in a chemical environment. Much ofthenew equipment reflects this process integration in the concept of cluster tools which may incorporate CVD, etching, sputtering, and ion implantation in one piece of equipment. 

---