Assessment of radiation dose hazards caused by radon and its progenies in tap water by the human dosimetric model

Radon is readily soluble in water, and radon exposure caused by household water consumption may pose a threat to public health. In this study, the radon concentration in the tap water of residential buildings was measured, and the average value was 543.33 mBq L−1, which was in line with the radon concentration limit recommended by USEPA (11.11 Bq L−1) and EURATOM (100 Bq L−1), and also within the range of the results of radon concentration measurements in tap water in other countries or regions. Through water bath heating at different temperatures, the radon retention curves of multiple groups of samples at different temperatures were fitted and analyzed. The results showed that the radon retention continued to decrease between 25 and 70 °C, remained stable between 70 and 85 °C, and then continued to decline slowly. Combined with the measurement results, the effective doses of α- and β-particles emitted by 222Rn and its progenies to residents respiratory and alimentary tissues and organs were calculated using the computational model provided by ICRP under two typical water scenarios of shower and drinking water, and the results show that radon exposure caused by normal water consumption will not pose a serious threat to public health.

The effect of heating factors on the properties of heat-induced surimi gel under ohmic heating

Ohmic heating (OH) is a method that heat is generated within the food due to its electrical resistance, resulting in a relatively linear heating rate and uniform temperature distribution. Because surimi-based paste contains water and salts, the conductivity is sufficiently good for the ohmic effect. Gelation induced by OH greatly depends on heating conditions such as heating speed, heating time, or electrical conductivity. However, the detailed information obtained is quite limited. Therefore, in order to clarify how ohmic heating affects the physical properties of surimi gel under OH, gels from croaker surimi (SA grade) were obtained using different heating conditions (heating speed, heating time, or salt concentration - electrical conductivity). Furthermore, the gels heated by ohmic heating were compared with the gel obtained by conventional water-bath heating. The results showed that, at the same heating rates, higher salt concentration generated better surimi gels for croaker surimi. Gels cooked ohmically at a slow heating rate performed significantly better than those cooked at a fast heating rate or heated conventionally in a water bath. There was little discernible difference in protein pattern between gels heated by OH and conventional water bath heating at fast heating rates with two different salt concentrations. The results also indicated that holding time at target temperature showed no effect on the gel. These results suggested that the properties of heat-induced surimi gels by OH are affected by not only heating speed but also holding time at maximum temperature and salt content.

Determination of available and carbonate antimony (Sb) in soil by Atomic Fluorescence Spectrometry

Antimony (Sb) is a toxic and potentially carcinogenic metalloid element. The toxicity of Sb in the environment strongly relies on its speciation. It is necessary to investigate the speciation and content of antimony in soil in order to understand better the real risk associated with Sb in the environment. This study developed water bath heating and soaking-AFS methods to determine the available and carbonate antimony in soil. Through analysis and mutual verification experiments in three different laboratories, the repeatability and reproducibility in the precision experiment were less than 3.44, the average recovery rate was more than 98.1%. These methods were accurate, reproducible and effective for detecting the content of available and carbonate antimony in soil.

Evaluation of Thermal Effects on the Bioactivity of Curcumin Microencapsulated with Porous Starch-Based Wall Material Using Spray Drying

Curcumin was microencapsulated by porous starch using a spray dryer with a particle size between 1.5 and 2.0 µm and subjected to water bath (40–100 °C) and oven heating (150–200 °C) in comparison to non-encapsulated samples. The minimum possible encapsulation rate ranged from 26.75 to 52.23%. A reasonable thermal stability was observed after water bath heating with regard to 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH) scavenging activity. On the other hand, the increase in oven heating temperature caused significant alterations compared with the control samples (p < 0.05). The encapsulated particles subjected to oven heating at 170 °C demonstrated serious collapse. The DPPH scavenging activity of non-encapsulated curcumin was significantly reduced (p < 0.05) from 48.94% ± 3.72% (control, 0 °C) to 40.42% ± 2.23% (oven heating, 160 °C); however, remained stable for the encapsulated samples (51.18% ± 4.86%–50.02% ± 1.79%) without significant difference (p < 0.05). The ABTS scavenging activity was promoted as a function of the oven heating temperature. Both DPPH and ABTS free radical scavenging activities remained stable after water bath. Nevertheless, the color of microencapsulated curcumin was better preserved in comparison to the controls.

Electrochemical Performances Investigation of New Carbon-Coated Nickel Sulfides as Electrode Material for Supercapacitors

A new carbon-coated nickel sulfides electrode material (NST/CNTs@C) has been synthesized through an easy-to-operate process: NiS2/CNTs which was prepared by a hydrothermal method reacted with BTC (1,3,5-benzenetricarboxylic acid) under the condition of water bath heating to obtain the precursor, and then the precursor was calcined in 450 °C under a nitrogen atmosphere to obtain NST/CNTs@C. The electrochemical performance of NST/CNTs@C has been greatly improved because the formation of a carbon-coated layer effectively increased the specific surface area, reduced the charge transport resistance and inhibited the morphological change of nickel sulfides in the charge–discharge process. Compared with pure NiS2 and NiS2/CNTs, NST/CNTs@C presented great specific capacitance (620 F·g−1 at a current density of 1 A·g−1), better cycle stability (49.19% capacitance retention after 1000 cycles) and more superior rate capability (when the current density was raised to 10 A·g−1 the specific capacitance remained 275 F·g−1).