Alpay Teoman Yıldız 030050014 - 9th week

Bright Dipping:

Bright-Dipping solutions are used for ferrous and nonferrous alloys and usually involve mixtures of two or more of the acids, sulfuric, phosphoric, chromic, nitric, and hydrochloric. The acid ratios and concentration vary widely. Dipping times range from 5 sec to 5 min or more. Some bath compositions and dipping conditions give a simple bright, clean appearance; others give a smoothing action with a brilliant appearance. Thus, the processes range in action from bright dipping to chemical polishing. Whenever nitric acid is used, special precautions are necessary. The nitrogen oxide fumes are poisonous and must be removed by proper ventilation.

Durney J.L., Electroplating Engineering Handbook, p.166

Weibull Distribution:

The Weibull distribution is useful in a great variety of applications, particularly as a model for product life. It has also been used as the distribution of strength of certain materials. One reason for its popularity is that it has a great variety of shapes. This make extremely flexible in fitting data, and it empirically fits many kinds of data. It may be suitable for a "weakest link" type of product. In other words, if a unit consists of many parts, each with a failure time from the same distribution, and if the unit fails with the first part failure, then the Weibull distribution may be suitable for such units. For example, the life of a capacitor is though to be determined by the weakest portion of dielectric in it.

Nelson W., Applied Life Data Analysis, p.36

Buffering Mechanisms:

Buffering mechanisms considered include aluminum buffering, silicate mineral buffering, cation exchange, organic buffering, and the effect of anion immobilization precesses such as nitrade uptake and sulfate adsorption. The effects of acidic inputs on capacity factors such as exchange acidity, exchangable base content, and sulfate adsorption capacity are considered, as are related natural processes such as acidification due to accumulation of bases in biomass. Particular attention is paiid to intensity effects, such as the effect of increased concentration on anions associated with strong acids on the chemical composition of the soil solution, as they are likely to be highly nonlinear with the respect to the capacity factors. These include pH, aluminum mobilization, and loss of alkalinity in the soil solution, which in turn may result in acidification of drainage waters.

Lindberg S.E., Norton S.A., Soils, Aquatic Processes, and Lake Acidification, p.1

Safety Lead Time:

Lead time is the time to procure or manufacture an item. In material requirements planning, lead time for all items covered by MRP is part of the MRP database. Due to unforseen events, it may take more time than planned lead time to purchase or make an item. When safety lead time is employed, shop orders or purchase orders are released and scheduled to arrive one or more periods earlier to allow for potential delays. Consequently, purchase orders and production orders are released and are the MRP logic would require. Safety lead time can be used in practice with safety stocks use safety lead time when there is an uncertainty in the timing of delivery from a vendor who misses delivery dates.

Swamidass M.P., Encyclopedia of Production and Manufacturing Management, p. 655