• Archives of design research
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• no.16
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• pp.1-14
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• 1996

As the marketing strategy of corporations has been changing in various ways, the type of new product development has also bC'en changing in dim~rent ways. The types of changes include, among oiller things, product development. wit.h a new concept., revolut.ionary product development., new brand product. development., improvement. of existing product. and development. in model changes. The design development has similarly advanced with the growth in scient.ific approach in t11e design process of new product. development. in relat.ion t.o each t.ype of product development.. Ilowever, in view of the design approach or st.rat.egy for each t.ype, different. kinds of method of development is necessary. In order to increase t.he life cycle of an existing product. which has reached its mature stage and to respond t.o the changes 111 time t.hrough product improvement., it is becoming more imtxJrl.ant for Ule corporation to confonn wiU1 the changes in time by being able to sat.isfy the consumer! s needs, way of thinking and luxury inclination by utilizing the changes in design. However, it is very difficult to decide on a design using different development. methods which would clearly meet such neL'

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.4
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• pp.311-325
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• 2007

The concept of metal bioavailability, rather than total metal in soils, is increasingly becoming important for a thorough understanding of risk assessment and remediation. This is because bioavailable metals generally represented by the labile or soluble metal components existing as either free ions or soluble complexed ions are likely to be accessible to receptor organismsrather than heavy metals tightly bound on soil surface. Consequently, many researchers have investigated the bioavailability of metals in both soil and solution phases together with the key soil properties influencing bioavailability. In order to study bioavailability changes various techniques have been developed including chemical based extraction (weak salt solution extraction, chelate extraction, etc.) and speciation of metals using devices such as ion selective electrode (ISE) and diffusive gradient in the thin film (DGT). Changes in soil metal bioavailability typically occur through adsorption/desorption reactions of metal ions exchanged between soil solution and soil binding sites in response to changes in environment factors such as soil pH, organic matter (OM), dissolved organic carbon (DOC), low-molecular weight organic acids (LMWOAs), and index cations. Increasesin soil pH result in decreases in metal bioavailability through adsorption of metal ions on deprotonated binding sites. Organic matter may also decrease metal bioavailability by providing more negatively charged binding sites, and metal bioavailability can also be decreases as concentrations of DOC and LMWOAs increase as these both form strong chelate complexeswith metal ions in soil solution. The interaction of metal ions with these soil properties also varies depending on the soil and metal type.