Computer — Personal Source

Computer-based sources include on-line and CD-ROM databases containing abstracts from health and safety journals, information on hazardous chemicals and details of relevant legislation. Computer programmes are also available containing statistical data on topics such as personal protective equipment performance and noise data analysis. 

A micro fuel cell is a compact miniaturized fuel cell with sizes ranging from a few square millimeters to 1000 mm. They are used as a portable power source for cell phones, laptop computers, personal digital assistants, and other portable low-power electronic devices. The power densities of miniature FCs range from a few tens of microwatts per square centimeter up to several hundreds of milliwatts per square centimeter. Miniature fuel cells... 

The hardware situation continued to evolve. Personal computers became ever more powerful in terms of speed and the amount of random access memory (RAM) and hard drive capacity. The price of PCs continued to fall. Clusters of PCs were built. Use of the open-source Linux operating system spread in the 1990s. Distributed processing was developed so a long calculation could be farmed out to separate machines. Massively parallel processing was tried. All these changes meant that the days of the supercomputers were numbered. 

In this method an Ar+ laser-pumped rhodamine 101 laser was used as the heat and probe source. The signal from a silicon photocell with a 1 mm2 photosensitive surface, which was used as a laser radiation detector, was processed with an inexpensive personal computer. The detector limit is 5 pg of phosphorus/ml. 

The ellipsometer used in this study is described elsewhere(3). It consists of a Xenon light source, a monochromator, a polarizer, a sample holder, a rotating analyzer and a photomultiplier detector (Figure 1). An electrochemical cell with two windows is mounted at the center. The windows, being 120° apart, provide a 60° angle of incidence for the ellipsometer. A copper substrate and a platinum electrode function as anode and cathode respectively. Both are connected to a DC power supply. The system is automated with a personal computer to collect all experimental data during the deposition. Data analysis is carried out by a Fortran program run on a personal computer. 

In the last decade, for many toxicologists the on-line literature search has changed from an occasional, sporadic activity to a semicontinuous need. Usually, nontoxicology-related search capabilities are already in place in many companies. Therefore, all that is needed is to expand the information source to include some of the data bases that cover the types of toxicology information one desires. However, if no capabilities exist within an organization, one can approach a university, consultant, or a private contract laboratory and utilize their on-line system at a reasonable rate. It is even possible to access most of these sources from home using a personal computer. The major available on-line data bases are described in the following. 

The polynomial root-solving program POLRT was used in the examples below. It is from the IBM Scientific Subroutines. A listing of the source program is given in Table 10.1. POLRT is vyy fast, even on a personal computer. 

The battery industry has seen enormous growth over the past few years in portable, rechargeable battery packs. The majority of this surge can be attributed to the widespread use of cell phones, personal digital assistants (PDA s), laptop computers, and other wireless electronics. Batteries remained the mainstream source of power for systems ranging from mobile phones and PDA s to electric and hybrid electric vehicles. The world market for batteries was approximately 41 billion in 2000, which included 16.2 billion primary and 24.9 billion secondary cells. 

Technology advances in electronics such as process control instrumentation systems, computer capabilities, programmable logic controllers, and the use of independent PC s (personal computers) at field locations for special dedicated functions present new challenges to incident investigation. Some of the advances are so rapid that the team may not have the internal expertise to determine failure scenarios, sequences, and modes. The suppliers and manufacturers of these high-tech devices are sometimes the only source of credible information on failure modes of these devices. 

Action. Identify useful sources of information and their location. Obtain personal copies of essential/useful information. Initiate a filing and reference system for useful information (preferably on computer disk). Prepare a complete design specification. Identifi the essential information that is available. Identify the information that is required. Obtain all necessary information. 

Personal computers (PCs) are important sources of VOCs in office and homes (Bako-Biro et al., 2004).Thus, the TVOCs emission rate per PC observed in a glass chamber study was as high as 486.6 pg/h while individual emission rates for toluene and phenol were 47 and 63 pg/h respectively. Other prominent chemicals emitted by PCs include, 2-ethylhexanol, formaldehyde and styrene (Bako-Biro et al., 2004). (See Chapter 17 for a more detailed discussion of VOCs in electronic devices.)... 

Polymer additives, which are used in high quantities in a plastic material, can contain residues of contaminants from production. Kaiser, Lorenz and Bahadir (1992) found low contents of PAHs within plastic additives. Both classes of compounds can be found in dust that accumulates in personal computers. Ren, Cheng and Chen (2006) showed that heated plastic parts are not the only source for PAH because the concentrations of PAH in dust are higher in offices were cigarettes are smoked. Anyhow, the study alleged a significantly higher PAH exposure of workers if a PC is present in the room. 

The emission of a complete set of personal computers and monitors are described by Nakagawa et al. (2003). Several VOC like benzene, toluene, etc. were identified and quantified. The results are shown in Table 17.3. The emission rates of aliphatic hydrocarbons, terpenes, esters, ketones, alcohols and halogens were not found to be significantly different for PCs with CRT and TFT monitors. In the case of aromatic hydrocarbons the emission rates were higher if a PC with CRT monitor was used. The same was found for aldehyde emissions but the differences in emission rates were lower. The separate test CRT monitor and the associated computer in this study proved that the monitor was the main source of chemical emissions. 

---