This Letter describes new work on the determination of the Newtonian constant of gravitation, G, carried out at the BIPM since publication of the first results in 2001. The apparatus has been completely rebuilt and extensive tests carried out on the key parameters needed to produce a new value for G. The basic principles of the experiment remain the same, namely a torsion balance suspended from...

CuO nanosheets, Cr-doped CuO nanosheets, and Cr-doped CuO nanorods were prepared by heating a slurry containing Cu-hydroxide/Cr-hydroxide. Their responses to 100 ppm NO(2), C(2)H(5)OH, NH(3), trimethylamine, C(3)H(8), and CO were measured. For 2.2 at% Cr-doped CuO nanorods, the response (R(a)/R(g), R(a): resistance in air, R(g): resistance in gas) to 100 ppm NO(2) was 134.2 at 250 °C, which was...

The effect of CuO doping on the electrical resistance and the sensitivity of thick film gas sensors based on CuOdoped (1%, 2% and 5% by wt.) SnO2has been investigated by us. A suitable gas sensor structure wasfabricated on 1 ̋x1 ̋ alumina substrate using thick film technology. The fabricated sensor‟s reaction with H2S gas (250 ppm-1000 ppm)was tested in the temperature range of 150350 ̊C. At 250 ̊C...

A heavy metal ion sensor was constructed by cross-linking melanin onto the gold electrode of quartz crystal microbalance (QCM). A mercury ion sensitivity of 518+/-37 Hz/ppm was observed, a substantial increase in sensitivity compared to previous reports of 10-50 Hz/ppm with the limit of detection at 5 ppb. Detection of other metal ions including Sn(2+), Ge(4+), Li(+), Zn(2+), Cu(2+), Bi(3+), Co...

The use of Catechin as an antibacterial agent is becoming ever-more common, whereas unstable and easy oxidation, have limited its application. A simple and low-energy-consuming approach to synthesize highly stable and dispersive Catechin-Cu nanoparticles(NPs) has been developed, in which the stability and dispersivity of the NPs are varied greatly with the pH value and temperature of the reacti...

We examined the concentrations of chromium (Cr), nickel (Ni), cadmium (Cd) and lead (Pb) in Rook Corvus frugilegus eggshells from 43 rookeries situated in rural and urban areas of western (=intensive agriculture) and eastern (=extensive agriculture) Poland. We found small ranges in the overall level of Cr (the difference between the extreme values was 1.8-fold; range of concentrations=5.21-9.40...

Two simple and fast methods for the extraction of the nitrite ion (NO(2)(-)) from food samples have been developed. The methods were characterized by UV-visible spectroscopic and electrochemical measurements, and their performance for NO(2)(-) extraction was compared with a standard method. The extraction methods yielded relative recoveries between 100 and 120% with good reproducibility of 3.9%...

The Lagos lagoon is a depository of last resort for over 70% of the surface runoffs, drainage channels and important rivers flowing from interior Nigeria to the Atlantic Ocean. The surrounding densely populated and industrialized areas often result in the introduction of potential harmful materials into the Lagoon. This work is aimed at providing reference data for the quality assessment of the...

The availability of Te is constrained by the production rate of its main parent compound (copper) and a debate is going on related to the potential supply of Te for very large scale CdTe PV deployment. However, recent investigations point to the existence of Te-rich ores in several places of the world that are likely to allow economic recovery of Te, independently of the production of copper. C...