Construction Standards and Techniques

The Act also required EPA to work with organizations involved in establishing national building construction standards and techniques and to soKcit public comments to develop model construction standards and techniques for controlling radon levels in new buildings. The Act further required EPA to work to ensure that the model standards and techniques so developed were adopted by the appropriate private and governmental entities. 

The EPA issued Model Standards and Techniques for the Control of Radon in New Residential Buildings in 1994. The publication was intended to serve as a model for jurisdictions developing building codes or standards apphcable to their radon control requirements, primarily for one- and two-family homes and other residential buildings of three stories or less. There is no requirement in the Act that new homes meet any specific radon level or that private home owners must test their homes. Consistent with its limited authority under the Act, the EPA was careful to point out in several sections that the Model Standards were not intended to supersede radon resistant 

Air and Radiation, Model Standards and Techniques for the Control of Radon in New Residential Buildings, EPA 402-R-94-009 (Mar. 1994) [hereinafter Model Standards], avail-ahk at www.epa.gov/radon/pubs/newconst.html. 

Office of Air and Radiation, Building Radon Out A Step-by-Step Guide on How to Build Radon-Resistant Homes, 402-K-01-004 (Apr. 2001) [Building Radon Out], availabk at http //www.epagov/radon/pubs/index.html. 

---

Model construction standards and techniques. Technical assistance to States for radon programs. 

As indicated above, silicon sensors have become the standard in diode thermometry and an extensive amount of data exists for them. Typical long-term stability is on the order of 50 mK, while short-term stability can be as low as a few millikelvin. This stability makes the diode competitive with industrial grade platinum thermometers with the added benefit of being usable to as low as 1 K. The upper temperature limit for commercially available diode sensors is around 400 K. This limit is determined by the properties of silicon, the metallurgy of the contact areas, and also by the construction materials and techniques used in device packaging. 

However, it is often criticized that multi-ton quantities cannot be reduced representatively to 1 g samples burnt in conventional bombs and that milling MSW to 2 mm particles alters the composition. To check this criticism a - compared with the usual instruments - huge combustion calorimeter was constructed at the National Institute of Standards and Techniques in Gaithersburg, MD/USA [144]. With a combuster of about 0.2 m volume in a calorimeter of 1.33 m outer diame-... 

In the past, PTRC screening was mainly based on gas chromatography-mass spectrometry (GC-MS) [116]. The choice of GC-MS was based on a number of good reasons (separation power of GC, selectivity of detection offered by MS, inherent simplicity of information contained in a mass spectrum, availability of a well established and standardized ionization technique, electron ionization, which allowed the construction of large databases of reference mass spectra, fast and reliable computer aided identification based on library search) that largely counterbalanced the pitfalls of GC separation, i.e., the need to isolate analytes from the aqueous substrate and to derivatize polar compounds [117]. 

Generally any deviation from a perfect surface is considered a defect and can originate from several sources, those that occur naturally on the clean surface or from contaminants. It is useful to understand the most common types of defect on the surface in order to interpret STM images of deposited adsorbates. It is also important to minimize these surface defects, especially from the perspective of nanoscale device construction on Si [17,18] where defects could alter device performance. A surface, prepared using standard annealing techniques in UHV, will typically contain a defect density of a few percent. 

In 2002 several manufacturers can provide advanced water electrolysis systems that are standardized, compact in size, need minimal operator intervention and require little maintenance. The basic electrolysis reaction has not changed. However new cell designs, materials of construction, standardized designs and manufacturing techniques have enabled manufacturers to decrease dramatically the fixed costs per unit of capacity for electrolysis technology. In addition, these new systems operate automatically and require very little maintenance, which reduces personnel costs48. 

Emission spectroscopy is widely used for both qualitative and quantitative analysis. The high sensitivity and the possible simultaneous excitation of as many as 72 elements, notably metals and metalloids, makes emission spectroscopy especially suited for rapid survey analysis of the elemental content in small samples at the level of 10 /ug/g or less. With control over excitation conditions to maintain constant and reliable atomization and excitation, the spectral line intensities can be used for quantitatively determining concentrations. An analytical curve must be constructed with known standards, and often the ratio of analyte intensity to the intensity of a second element contained in, or added to, the sample (the internal-standard method) is used to improve the precision of quantitative analyses. Preparation of standards for arc and spark techniques requires considerable care to match chemical and physical forms to the sample this is not commonly required for ICP discharge. 

The virtual orbitals obtained by means of the perturbation theory approximation are then employed to construct a full set of all the singly- and doubly-excited configurations which provide the final VB-like wavefianction Eq. (11). Finally, the multi structure VB (non-orthogonal Cl) problem is set up and solved vaiiationally according to standard VB techniques, see Raimondi et al (1977) and Cooper et al, (1987). 

The two most important techniques are the construction of a calibration plot using standards and the method of standard addition. 

WO3 is an example of another class of electroactive material, metal oxides, which has been used to construct microelectrochemical devices. WO3 is a wide-band-gap semiconductor, with high resistance in its neutral state.Upon reduction, WO3 intercalates cations such as H" ", Li" ", and Na and becomes conducting. W03 based transistors, showing sensitivity to pH and to Li" concentration have been demonstrated in solution electrolytes. A schematic of a MEEP/WO3 device is shown in Figure 3. WO3 is confined to the required electrodes, using standard photolithographic techniques. 

SECM instruments suitable for imaging require a PC equipped with an interface board to synchronize acquisition of the electrochemical data with the movement of the tip. Building an SECM for kinetic experiments at fixed tip position or approach curve measurements is relatively easy, but fairly sophisticated software and some electronic work is necessary to construct a computer-controlled apparatus for imaging applications. Details on the construction of SECM instruments can be found elsewhere [6, 13-18, 53, 55]. An SECM is now available commercially from CH Instruments, Inc. (Austin, TX, USA). The instrument employs piezoelectric actuators, a three-axis stage, and a bipotentiostat controlled by an external PC under a 32-bit Windows environment. Various standard electrochemical techniques are incorporated along with SECM imaging, approach curves, and the modes described in Sect. 3.3.I.I. 

The covered test chamber was constructed from a 3-in. Pyrex pipe joint, provided with a clamp-locking O-ring seal. By use of standard glassblowing techniques, the pipe was cut and sealed to give a capacity of 0.5 liter (Fig. 3). An outlet tube was annealed to the cover, with an inlet positioned near the bottom of the chamber. A stainless-steel inlet screen was positioned 3 cm above the bottom of the dish, dividing the chamber into an upper egg compartment and a lower... 

Sorathia and co-workers [51] investigated the use of smaller scale fire test methods. From these investigations, two methods, differing in concept and technique, were developed. The methods developed by the UL in the late 1950s are still in use today and are described in the Approval Standard for Class 1 Roof Covers, FM 4470 [52] and Fire Test of Roof Deck Constructions, UL 1256 [53]. 

---