History and current development

For the investigation of clean crystalline surfaces ultrahigh vacuum has to be used. To keep a surface clean for time periods of hours, gas pressures lower than 10-7 Pa are required (see Exercise 2.1). To provide such conditions is quite demanding. A textbook on vacuum technology is Ref. [312] and a review on history and current developments of vacuum technology is Ref. [313],... 

This paper is intended to present the history and current development status of a relatively new application for commercially produced polymeric MDI and to demonstrate its potential. The monomer upon which polymeric MDI is based is diphenylmethane diisocyanate ... 

Cahill, V., 2001. A Short History and Current Development of UV-Curing for Ink Jet Printing. RadTech International, Bethesda, MD, USA. 

Table 10.1 History and current development of catalyst for ammonia synthesis...

This overview is an attempt to briefly cover the history and recent developments In environmentally degradable commodity and specialty polymers and plastics. Degradation pathways are mentioned, polymer types, including blends, are reported and the limitations of current testing protocols raised. The chapter concludes with generalizations on structural requirements for degradable polymers. 

When designing protocols to measure deposition, a number of clinical factors need to be considered and incorporated into the study design subjects age, sex, smoking history, and current drug regimens, presence of a viral infection, severity of disease, stability of pulmonary function, and other outcome measures that could affect the inhalation of the radioaerosol, the measurement of deposition, and the results. Some of these also apply when using healthy volunteers as subjects for deposition studies. For example, we allow a 4- to 6-week recovery period between repeat studies for subjects who have suffered an exacerbation of their asthma or developed a chest cold or infection after enrollment. 

Biamperometric titration involves the application of a fixed, usually small, voltage across a pair of identical electrodes. First performed as early as 1897 the technique was rediscovered and applied in 1926. Although the titration curves are not linear, the end point is usually marked by a sharp change in the current. A text ( 44) and a succession of reviews (45) describe the history and subsequent development of these and related titration techniques. 

A survey is given of various industrial applications of solids mixing and the role it plays in our daily lives. This is followed by a review of the history and current status of the technology of solids mixing. Finally, a proposal is presented for further development of this technology and concomitant fundamental research. 

The present-day food industry is almost totally dependent on refrigeration in one form or another, to manufacture, preserve, store and bring the product to the point of sale. The few examples chosen in Chapters 14-18 indicate the general principles. The history, development and current practice of refrigeration of foodstuffs is largely the history, development and current practice of the refrigeration industry itself. 

The current-voltage and luminance-voltage characteristics of a state of the art polymer LED [3] are shown in Figure 11-2. The luminance of this device is roughly 650 cd/m2 at 4 V and the luminous efficiency can reach 2 lm/W. This luminance is more than adequate for display purposes. For comparison, the luminance of the white display on a color cathode ray tube is about 500 cd/m2l5J. The luminous efficiency, 2 lm/W, is comparable to other emissive electronic display technologies [5], The device structure of this state of the art LED is similar to the first device although a modified polymer and different metallic contacts are used to improve the efficiency and stability of the diode. Reference [2] provides a review of the history of the development of polymer LEDs. 

How will we identify the extra astrophysics required to reconcile the properties of CDM dark haloes with those of luminous galaxies We can start by developing knowledge of the evolutionary history of at least one place in at least one galaxy. We would be unlucky if that place were far from the norm alternatively, any theory that predicts such a history to be very unusual might be suspect -the galaxian Copernican principle. Kinematics and current spatial location are of course critical parameters, so that traditional stellar populations analyses are... 

The pharmacopeias have worked with the ICH process to facilitate the international environment of pharmaceutical research and product registration. On the other hand, the additional situation for compendia is that the standards which they have published now apply to all of the already marketed products. In that case a company has testing history and product history in their quality control departments. These are the most conservative elements within the pharmaceutical industry as is necessary to their task. Quality control departments are reluctant to change methods when they feel that their products are properly represented by the current of tests. Therefore, a tension is ereated between trying to develop harmonized standards, which facilitate one area of activity in the world of pharmaeeutieals, and not disturbing a satisfactory marketplace. A vast amount of progress has been made in the harmonization of phar-maeopeial methods. 

A very useful review of the history and development of the Declaration of Helsinki in the last four decades from its evolution from the principles enunciated in the Nuremberg Code of 1947 to the current version has been published in the British Journal of Clinical Pharmacology and is recommended reading, it includes the texts of the various versions of the Declaration. 

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