Improved Narrow Water Extraction Using a Morphological Linear Enhancement Technique

An improved water extraction method using a morphological linear enhancement technique is proposed to improve the delineation of narrow water features for the modified normalized difference water index (MNDWI) derived from remote sensing images. This method introduces a morphological white top-hat (WTH) transforming operation on the MNDWI to extract multi-scale and multidirectional differential morphological profiles and constructs a morphological narrow water index (MNWI). The MNWI can effectively enhance the local contrast of linear objects, allowing narrow water bodies to be easily separated from mountain shadows and other features. Furthermore, to accurately delineate surface water bodies, a dual-threshold segmentation method was also developed by combining an empirical threshold segmentation with the MNDWI for wide water bodies and an automatic threshold segmentation with the MNWI for narrow water bodies. This method was validated using three experimental datasets, which were taken from two different Landsat images. Our results demonstrate that narrow water bodies can be sufficiently identified, with an overall accuracy of over 90%. Most narrow streams or rivers keep a continuous shape in space, and the boundaries of the water bodies are accurately delineated as compared with the MNDWI method. Finally, the proposed method was used to extract the entire inland surface water of Fujian province, China

Extendable space-type switched-capacitor multilevel inverter with fault-tolerant capability

Low reliability is one of the main concerns in terms of multilevel inverters (MLI) due to the presence of a large number of switches and capacitors. Therefore, the fault-tolerant operation of MLIs has recently gained a great deal of attention. An extendable space-type switched-capacitor MLI topology with fault-tolerant characteristics is proposed in this paper. The proposed inverter employs a single direct-current voltage source and three capacitors to output staircase voltage levels with low distortion. The proposed topology is capable of tolerating open-circuit faults due to the separated charging paths of the inverter. Under pre-fault and post-fault operations, it preserves capacitor voltage balancing, voltage boost capability, as well as the ability to supply inductive loads. Furthermore, the voltage stresses of the switches and the voltage ripples of the capacitors are decreased or remain under post-fault operations. The proposed topology has been validated with a laboratory prototype in both dynamic and steady-state operations

GC-MS analysis of off-odor volatiles from irradiated pork

The main compounds of off-odor volatiles from irradiated refrigerated vacuum-packaged pork were analyzed by gas chromatograph/mass spectrometer (GC-MS). The analytical results showed that the main compounds of off-odor volatiles were dimethyl disulfide, dimethyl sulfide, dimethyl trisulfide, S-methyl thioacetate, and methanethiol. It was proved that the off-odor volatile came from irradiated S-containing amino acid and thiamin

Pollution Characteristics and Health Risks of Polycyclic Aromatic Compounds (PACs) in Soils of a Coking Plant

Coke production is an important source of environmental polycyclic aromatic compounds (PACs), including parent polycyclic aromatic hydrocarbons (PAHs) and their derivatives. The focus near coking plants has primarily been on parent-PAH contamination, with less attention given to highly toxic derivatives. In this study, soil samples were collected from both within and outside of a coking plant. The concentrations of parent-PAHs and their derivatives, including methylated-PAHs, oxygenated-PAHs, and nitrated-PAHs, were examined. Spatial interpolation was employed to determine their spatial distribution patterns. Methods for identifying potential sources and conducting incremental lifetime cancer risk analysis were used. This could achieve a comprehensive understanding of the status of PAC pollution and the associated health risks caused by coke production. The concentrations of total PACs inside the plant ranged from 7.4 to 115.8 mg/kg, higher than those outside (in the range of 0.2 to 65.7 mg/kg). The spatial distribution of parent-PAH concentration and their derivatives consistently decreased with increasing distance from the plant. A significant positive correlation (p < 0.05) among parent-PAHs and their derivatives was observed, indicating relatively consistent sources. Based on diagnostic ratios, the potential emission sources of soil PACs could be attributed to coal combustion and vehicle emissions, while principal component analysis–multiple linear regression further indicated that primary emissions and secondary formation jointly influenced the PAC content, accounting for 60.4% and 39.6%, respectively. The exposure risk of soil PACs was dominated by 16 priority control PAHs; the non-priority PAHs’ contribution to the exposure risk was only 6.4%

GC-MS analysis of off-odor volatiles from irradiated pork

The main compounds of off-odor volatiles from irradiated refrigerated vacuum-packaged pork were analyzed by gas chromatograph/mass spectrometer (GC-MS). The analytical results showed that the main compounds of off-odor volatiles were dimethyl disulfide, dimethyl sulfide, dimethyl trisulfide, S-methyl thioacetate, and methanethiol. It was proved that the off-odor volatile came from irradiated S-containing amino acid and thiamin