Background & Aims of the Study: Heavy metals contaminate drinking water, air and soils. It is very harmful for humans and other live organisms. Phytoremediation is one of the direct bio-remediation methods for heavy metal removal from polluted water and soils. This method is accepted environmentally, economically and aesthetically. The purpose of this study was to assess Tamari...

relief wells are used extensively to relieve excess hydrostatic pressure in pervious foundation strata overlain by impervious top strata, conditions which often exist landward of levees and downstream of dams and hydraulic structures. placing well outlets in below-surface trenches or collector pipes helps dry up seepage areas downstream of levees and dams. relief wells are often used in combina...

We explore the technological evolution of three microprocessor firms between 1976 and 2004. We trace how two initially small entrants (Intel and AMD) competed against a larger and more established incumbent (IBM). We show that changes in inter-firm relationships (as reflected by competitive and cooperative events) affect patenting strategies. Periods of increased competition correspond to great...

This paper considers vertical relations between an upstream manufacturer and a downstream retailer that can independently obtain a low-quality, discount substitute. The analysis reveals that under full information the retailer offers both varieties only if it is optimal to do so under vertical integration. However, when the retailer is privately informed about demand, then the retailer will off...

It is well known that vertical integration can change the pricing incentive of an upstream producer. However, it has not been noticed that vertical integration may also change the pricing incentive of a downstream producer and the incentive of a competitor in choosing input suppliers. I develop an equilibrium theory of vertical merger that incorporates these additional strategic considerations....

Inventory management in markets with substituting customers is extremely challenging, not only for a downstream wholesaler, but also for upstream manufacturers. Motivated by the structures in the agrochemical market, we analyze the optimal production and stocking quantities of a manufacturer and a wholesaler, respectively, in a two-stage supply chain with upstream competition and vertical infor...

International subcontracting relationships are often characterized by considerable power asymmetries. The actors in global value chain obtained different profits. Different governance dominant modes reflect different roles of countries and enterprises played in the global value chains and result in different industrial international competitiveness in the end Through a relation model of upstrea...

T bullwhip effect is a major source of supply chain inefficiency. Whereas prior literature has identified a number of potential contributing factors and recommended such remedies as information sharing enabled by information technology (IT) or electronic linkage (EL), few studies have provided empirical support. We use industry-level data to examine whether EL use with buyer and supplier indust...

Buffers decouple fluctuations in the material flow. It is common wisdom in industry that a full buffer indicates a downstream bottleneck and an empty buffer indicates an upstream bottleneck. Numerous different bottleneck detection methods use this approach to detect the bottlenecks. However, so far this common wisdom on the shop floor has not yet been verified academically. The authors tested t...

Using a Hotelling-type product differentiation model (linear city model), we investigate the location strategies of upstream and downstream firms. We show that when transport costs of upstream firms are large, higher transport costs decrease the level of product differentiation of downstream firms. We also show that more inefficient transport technologies of upstream firms may enhance welfare. ...