SPECIFIC CHALLENGES

In Chapter 2, a number of grand challenges for chemists and chemical engineers were delineated to promote national security and homeland defense, based on the views of workshop participants. This chapter goes one step further to identify scientific barriers that prevent those challenges from being met. 

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The archiving of electronic data poses more specific challenges. GLP requires records retention and retrieval of archival records. Since software used for the creation of electronic records is upgraded at a rapid pace, the requirement of retrievable archived records can be difficult to comply with. Even when stored on electronic media, the records have to comply with the records retention period and be retrievable. The collection, storage, and retrieval of electronic records should address all GLP aspects, including environmental conditions to ensure the integrity of the media. 

Why do polymers with different viscosities present specific challenges when manufacturing blends ... 

The goal of this chapter is twofold. First we wish to critically compare—from both a conceptional and a practical point of view—various classical and mixed quantum-classical strategies to describe non-Born-Oppenheimer dynamics. To this end. Section II introduces five multidimensional model problems, each representing a specific challenge for a classical description. Allowing for exact quantum-mechanical reference calculations, aU models have been used as benchmark problems to study approximate descriptions. In what follows, Section III describes in some detail the mean-field trajectory method and also discusses its connection to time-dependent self-consistent-field schemes. The surface-hopping method is considered in Section IV, which discusses various motivations of the ansatz as well as several variants of the implementation. Section V gives a brief account on the quantum-classical Liouville description and considers the possibility of an exact stochastic realization of its equation of motion. 

Unlike nickel, chromium metal does not produce allergic contact dermatitis. Some patients exhibit positive patch tests to divalent chromium compounds, but these compounds are considerably less potent as sensitizers than hexavalent chromium compounds. A case of chromium (chromic) sulfate-induced asthma in a plating worker, confirmed by specific challenge testing and the presence of IgE antibodies, has been reported. ... 

Rapid production scale-up procedures. If these procedures are established before they are needed, they can be implemented immediately in an attack. Although investigation into scale-up of all stages of production should occur, the scale-up of separation and purification is a specific challenge. 

After the second rinse has been filtered, a final 100-ml portion containing less than 100 cfu of the specific challenge microorganism is passed through the filter. This filter is then transferred to the appropriate recovery agar medium and incubated for recovery. 

Intimately related to these factors is the design of the device, formulation, and the interface with the patient. Much of the discussion below will focus on the implications of excipients on formulation challenges for inhaled aerosol products. This chapter summarizes excipients for pulmonary formulations from several perspectives (i) excipient selection based on principles of delivery, (ii) physicochemical requirements for excipients, and (iii) specific challenges for formulations faced with aerosol drug delivery systems, including (a) biological aspects, (b) microbiological aspects, (c) analytical issues, and (d) future prospects. 

These general challenges are addressed by examples of specific challenges that exemplify them. 

Despite this general decline, some companies are still doing excellently in 2004, the top three players boasted an average return on net assets (RONA) of more than 25 percent, while the bottom three players had to settle for less than six percent on average (Fig. 8.5). This spread, a factor of around four, is much bigger than in other industries. The top companies in specialty chemicals seem to know the formula for success, and we will share below our perspective on the specific challenges that need to be addressed in order to remain or become a top player in this increasingly problematic competitive arena. 

In this paper we consider two specific challenges. First, how might transition metals be linked to phosphazene high polymers Such systems are of interest as immobilized catalysts or materials with unusual electrical properties. Second, how can bioactive agents be attached to polyphosphazenes to prepare, for example, targeted, slow release chemotherapeutic agents ... 

Biomass-Derived Substrates Specific Challenges and Opportunities. 49... 

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