Empirical Design Approach

Determination of safety factors for the required UV dose due to lamp aging and fouling. Determination of UV intensity as a function of the transmittance or absorbance of filtered water samples by the point-source summation method or equivalent. The presence of suspended solids and colors can reduce the intensity of UV light in the waters. 

UV Dose-Response of Different Microorganisms in Drinking Water 

Determination of volume of water to be disinfected based on the exposure time and flow rate. 

The empirical design approach can be illustrated by a following example. 

A wastewater is treated by a conventional biological treatment and subsequently disinfected by a UV nnit snch that the pathogenic content is rednced to 170 MPN/100 ml. 

---

Clark, L. M., Pakalnis, R. C. (1997). An empirical design approach for estimating unplanned dilution from open stope hanging-walls and footwalls. In Proceedings of the 99" CIM Annual General Meeting, Vancouver, Canada. 

The design approach is particularly feasible for those reactions in which chemical and pore diffusion rates are most important. For flow related phenomena semi-empirical, dimensionless correlations must be relied on. Therefore in this book scale-up will be used in the more general sense with the airri of using methods that are fundamentally based wherever feasible. 

Mathews and Rawlings (1998) successfully applied model-based control using solids hold-up and liquid density measurements to control the filtrability of a photochemical product. Togkalidou etal. (2001) report results of a factorial design approach to investigate relative effects of operating conditions on the filtration resistance of slurry produced in a semi-continuous batch crystallizer using various empirical chemometric methods. This method is proposed as an alternative approach to the development of first principle mathematical models of crystallization for application to non-ideal crystals shapes such as needles found in many pharmaceutical crystals. 

In order for us to effectively develop and use these new tools, we must make the transition from an empirical, retrospective use of modeling to a planned design approach. The question to be addressed should not be Why didn t this experiment work Rather, we need a prospective outlook Can this work These new theoretical tools should be bringing new information to the chemist to be used in conjunction with experimental data already available. The success of computer aided design of chemicals will arrive when a chemist can sit at the terminal as the first step in the development process. 

Valve, Explosive Calculations. In the past, explosively actuated valves have been designed on an empirical basis because the interactions and forces involved in a valve operation were not fully understood. However, this design approach was satisfactory in that the size and design of the valves permitted a more than adequate amount of expl to be used to ensure proper operation of the valves. That is, the driving force available from the extra expl pro-... 

Similar to the design approaches employed in most water and wastewater treatment processes such as biological wastewater treatment, there are empirical (also called irrational) and model-based (rational) methodologies used for design of UV unit for aqueous-phase disinfection. The first one is based on empirical experience and has traditionally been used in the water industry, while the second one is based on a series of detailed mathematical analyses and experimental measurements and is still in the research phase. In the design, one will determine the requirement of UV lamps applied to the water based on the characteristics of water such as flow rate and the size of the disinfection unit. 

Both empirical and rational methods have been successful in developing novel fluorescent sensors. However, on the one hand, empirical design and synthesis may require considerable trial and error. On the other hand, the rational design approach described above is limited to analytes that can sufficiently change the oxidation or reduction potential. Further, even in the case of theoretically designed molecules, the fluorescence properties may be unexpectedly influenced by environmental factors. The construction of libraries of fluorescent molecules is one way to overcome some of these problems in the development of novel fluorescent sensors. 

Once the rules of siRNA design and target selection became more accepted, in silico siRNA prediction came to the fore. Bioinformaticists now use empirical and theoretical design rules to generate siRNA molecules as described earlier. However, because these design approaches use different algorithms, their siRNA design... 

T , See melt temperature, theorem See mathematical theorem, theoretical versus actual properties See plastics, theoretical versus actual values of. theory A unifying principle that explains a body of facts and tbe laws that are based on those facts. See atomic theory design design-failure theory design theory and strength of material empirical engineering approach versus practical approach mathematical theorem mixing theory. 

The design traffic is expressed as cumulative equivalent standard loads (ESAL) over the design period. To convert daily traffic to ESAT, two different approaches related to the equivalency factors are considered. The first approach is applied to the empirical design method, for flexible pavements with only a thin asphalt layer (25 to 40 mm), and the second approach is applied to the mechanistic design method, for flexible pavements with asphalt, unbound or FfBM layers. 

The discussion presented in the previous sections assumes that a process model is available. However, optimization of process operation is also possible when process models are not available. In this case, one must rely on available experimental process data and/or empirical modeling approaches. For instance, the process performance can be mapped within the experimental region of interest with the help of experimental design techniques. Experiments are performed in accordance with the proposed experimental design and empirical cubic models (or other types of empirical models) are fitted to the obtained experimental data. Then, the empirical models can be used to provide the searched optima. This type of experimental design-based optimization procedure was performed to optimize the operation of fermentors used for production of bacterial polyesters (177], as it is very difficult to develop a fundamental model for bacterial polymerizations. In this particular case, the medium composition was manipulated to allow for maximization of polymer production and rninirnization of the batch time. 

Mitzi et al. have reported an optical-design approach which resulted in improvement of the short-circuit current and power conversion efficiency of CZTSSe solar cells. They have optimized the thickness of the upper-device layers in a way that allows maximum transmission into the CZTSSe absorber. This design approach was based on optical modeling of idealized planar devices with a semi-empirical approach for treating the impact of surface roughness. Effectiveness of the new device architecture based on thinner CdS and TCO layers was experimentally demonstrated by fabricating solar device with overall power conversion efficiency of 12.0% a new record in CZTSSe based devices. 

Three approaches can be used, viz. comparative design, theoretical design, and empirical design. 

---