Notice of RetractionCountermeasures of Payment Risk in Construction Contract
The contractor lacks of identification ability of risks in construction contracts, which result in loopholes and risks that could be avoid in the signing and implementation process of the instruction contract. Due to lack of identification and prevention of these risks, lead to the losses of the contractors in the project construction courses. To the contractor, the significant risk is the owner's payment risks. It is a universal phenomenon there exist plenty of owners in arrears with project payment or repudiate payment, which result not only from insufficient management of contractors, but also closely related to the credit of owners. This paper firstly elaborate contract management of construction project, and then analyze the risk of construction contract and put emphasize on employer payment risk. Finally, point out that employer payment bond is an effective method of risk transferring in preventing employer arrear, to ensure the profitability and construction can be carried through smoothly.
Surety Bonds for Construction Contracts
This book presents the complex field of suretyship for construction contracts by describing and analyzing each element of the surety bonding process in basic terms. Russell unravels the suretyship puzzle through numerous examples and extended case studies drawn from real-world experience. Sample bond forms and surety documents, as well as an extensive glossary of key terms, serve to further illustrate each step of the bonding process.
Electrochemical detection of copper(II) at a gold electrode modified with a self-assembled monolayer of penicillamine
A penicillamine (PCA) self-assembled monolayer (SAM) was prepared on a gold electrode. It has been found that the modified electrode exhibited a selective response to copper ions. As demonstrated by cyclic voltammetric experiments, the SAM-based electrode showed an attractive ability to preconcentrate efficiently traces of copper(II) from solutions. Under optimum conditions, the anodic peak current was proportional to the concentration of Cu(II) in the range from 8.0 × 10−7 to 1.0 × 10−4 M with a detection limit of 4.0 × 10−7 M. Moreover, this modified gold electrode is also characterized by excellent repeatability, showing a relative standard deviation of 3.2% for nine successive measurements of 1.0 × 10−5 M Cu(II). The PCA/Au SAM gold electrode was used for the determination of Cu(II) in a tap water sample and the results showed a good agreement with the data obtained by atomic emission spectrometry.