A major portion of persistent organic pollutants (POPs) is organochlorine pesticides (OCPs), in which carbon and chlorine are combined. During the last decade, a number of researches have been devoted to create emission inventories of OCPs at regional and global scales. The studies on residue inventories of OCPs, however, are sparse. In the absence of complete data and information on worldwide inventories of pesticides emissions and residues, a Simplified Gridded Pesticide Emission and Residue Model (SGPERM) has been developed to estimate the emissions and residues, and build pesticide emission and residue inventories. The SGPERM is an integration of a mathematical module, a relational database system, and a geographic information system. In this paper, a complete description of the model is given. A brief review of the model's application in developing emission inventories for α-HCH is introduced. The model is used to create global gridded residue inventories of α-HCH on cropland with a 1 • latitude by 1 • longitude resolution for 1980, 1990, and 2000, the first such residue inventories for any pesticide. The total global residues of α-HCH on cropland were 198 kt in 1980, 35 kt in 1990, and 1.2 kt in 2000, and the emissions from these residues were 11.8 kt in 1980, 2.3 kt in 1990, and 0.15 kt in 2000. Historical trends of α-HCH concentration in agricultural soil are also estimated at some locations in China and Japan, and match the monitoring data quite well.

During the summer of 2013, a 4-month spectroscopic campaign took place to observe the variabilities in three Wolf-Rayet stars. The spectroscopic data have been analyzed for WR 134 (WN6b), to better understand its behaviour and long-term periodicity, which we interpret as arising from corotating interaction regions (CIRs) in the wind. By analyzing the variability of the He II λ5411 emission line, the previously identified period was refined to P = 2.255 ± 0.008 (s.d.) days. The coherency time of the variability, which we associate with the lifetime of the CIRs in the wind, was deduced to be 40 ± 6 days, or ∼ 18 cycles, by cross-correlating the variability patterns as a function of time. When comparing the phased observational grayscale difference images with theoretical grayscales previously calculated from models including CIRs in an optically thin stellar wind, we find that two CIRs were likely present. A separation in longitude of ∆φ 90 • was determined between the two CIRs and we suggest that the different maximum velocities that they reach indicate that they emerge from different latitudes. We have also been able to detect observational signatures of the CIRs in other spectral lines (C IV λλ5802,5812 and He I λ5876). Furthermore, a DAC was found to be present simultaneously with the CIR signatures detected in the He I λ5876 emission line which is consistent with the proposed geometry of the large-scale structures in the wind. Small-scale structures also show a presence in the wind, simultaneously with the larger scale structures, showing that they do in fact co-exist.