Zhejiang Gongshang University

About: Zhejiang Gongshang University is a education organization based out in Hangzhou, China. It is known for research contribution in the topics: Adsorption & Supply chain. The organization has 8258 authors who have published 7670 publications receiving 90296 citations. The organization is also known as: Zhèjiāng Gōngshāng Dàxué.

Characterization and application of bioflocculant prepared by Rhodococcus erythropolis using sludge and livestock wastewater as cheap culture media

Abstract: A new bioflocculant was produced by culturing Rhodococcus erythropolis in a cheap medium. When culture pH was 7.0, inoculum size was 2 % (v/v), Na2HPO4 concentration was 0.5 g L−1, and the ratio of sludge/livestock wastewater was 7:1 (v/v), a maximum flocculating rate of 87.6 % could be achieved. Among 13 different kinds of pretreatments for sludge, the optimal one was the thermal-alkaline pretreatment. Different from a bioflocculant produced in a standard medium, this bioflocculant was effective over a wide pH range from 2 to 12 with flocculating rates higher than 98 %. Approximately, 1.6 g L−1 of crude bioflocculant could be harvested using cold ethanol for extraction. This bioflocculant showed color removal rates up to 80 % when applied to direct and disperse dye solutions, but only 23.0 % for reactive dye solutions. Infrared spectrum showed that the bioflocculant contained functional groups such as –OH, –NH2, and –CONH2. Components in the bioflocculant consisted of 91.2 % of polysaccharides, 7.6 % of proteins, and 1.2 % of DNA. When the bioflocculant and copper sulfate (CuSO4) were used together for decolorization in actual dye wastewater, the optimum decolorization conditions were specified by the response surface methodology as pH 11, bioflocculant dosage of 40 mg/L, and CuSO4 80 mg/L, under which a decolorization rate of 93.9 % could be reached.

Supplier encroachment strategy in the presence of retail strategic inventory: Centralization or decentralization?

Abstract: There has been extensive research on supplier encroachment. That is, a supplier sells to consumers through a direct retail subsidiary in addition to an independent retailer. However, most research assumes centralized encroachment, where the supplier makes decisions for the subsidiary. In this research, we make a major contribution by explicitly analyzing the option of decentralized encroachment, where the subsidiary makes its own pricing and/or quantity decisions. Furthermore, we make another major contribution by studying the retailer's possible use of strategic inventory as a countermeasure to achieve wholesale price concessions from the supplier. In a dual channel consisting of a retailer and a supplier and its subsidiary in a two-period model, we find that when the retailer can employ strategic inventory, decentralized encroachment outperforms centralized encroachment for the supplier and the retailer. Moreover, if the supplier adopts the strategy of decentralized encroachment, the retailer's use of strategic inventory always benefits the supplier, but it benefits the retailer only when the unit inventory holding cost is below a threshold. We also conduct numerical examples to further illustrate our analytical findings and gain more managerial insights.

Electrochemical detection of nitrite ions using Ag/Cu/MWNT nanoclusters electrodeposited on a glassy carbon electrode

Abstract: A glassy carbon electrode modified with Ag/Cu nanoclusters and multiwalled carbon nanotubes was fabricated using the electrodeposition method to detect nitrite in solution. This modified electrode showed electrocatalytic activity for the oxidation of nitrite. A cyclic voltammetry investigation of the electrochemical behavior of the modified electrode in nitrite solution revealed an intense oxidation peak for nitrite at 0.85 V. Upon increase of the nitrite concentration from 1.0 μmol L−1 to 1.0 mmol L−1, the current response increased linearly, with a detection limit of 2 × 10−7 mol L−1. The electrode exhibited good stability, as well as satisfactory performance in the detection of nitrite in lake water, drinking water and seawater.