Effects of different LED light colors on growth performance and harmful gas emission of broilers breeding in a digital rearing chamber

Refined management is an inevitable trend in the development of livestock husbandry.Accurate acquisition of breeding environment parameters is beneficial to improve breeding efficiency while reducing environmental pollution.Light is an important breeding environmental factor during broiler breeding.In this study,a short-term broiler breeding experiment was conducted with different light color illumination environments in a digital breeding chamber under lab conditions.According to experimental results,the Red Light(RL)group was conducive to the growth of broilers at 30 d of age with low NH3 emission concentration;the Green Light(GL)group inhibited the broiler growth;the Yellow Light(YL)group showed the highest average emission concentration of NH3 and lowest daily average emission concentration of CO_(2).According to the analysis of moisture content,pH value,and C/N in the broiler manure,it can be concluded that the physical and chemical properties of broiler defecation quantities were different under various light color illuminations,resulting in the difference in broiler growth conditions and harmful gas emissions.The study results could provide a research basis and ideas of reference to establish a relationship between LED illumination information,broiler growth performance,and harmful gas emission.

Applications of metal–organic frameworks for green energy and environment: New advances in adsorptive gas separation, storage and removal

The separation of gas molecules with similar physicochemical properties is of high importance but practically entails a substantial energy penalty in chemical industry. Meanwhile, clean energy gases such as H_2 and CH_4 are considered as promising candidates for the replacement of traditional fossil fuels. However, the technologies for the storage of these gases are still immature. In addition, the release of anthropogenic toxic gases into the atmosphere is a worldwide threat of growing concern. Both in academia and industry, considerable research efforts have been devoted to developing advanced porous materials for the effective and energy-efficient separation, storage, or capture of the related gases. In contrast to conventional inorganic porous materials such as zeolites and activated carbons, metal–organic frameworks(MOFs) are considered as a type of promising materials for gas separation and storage. In this contribution, we review the recent research advance of MOFs in some relevant applications, including CO_2 capture, O_2 purification, separation of light hydrocarbons, separation of noble gases, storage of gases(CH_4,H_2, and C_2 H_2) for energy, and removal of some gaseous air pollutants(NH_3, NO_2, and SO_2). Finally, an outlook regarding the challenges of the future research of MOFs in these directions is given.

Numerical and experimental analyses of methane leakage in shield tunnel

Tunnels constructed in gas-bearing strata are affected by the potential leakage of harmful gases,such as methane gas.Based on the basic principles of computational fluid dynamics,a numerical analysis was performed to simulate the ventilation and diffusion of harmful gases in a shield tunnel,and the effect of ventilation airflow speed on the diffusion of harmful gases was evaluated.As the airflow speed increased from 1.8 to 5.4 m/s,the methane emission was diluted,and the methane accumulation was only observed in the area near the methane leakage channels.The influence of increased ventilation airflow velocity was dominant for the ventilation modes with two and four fans.In addition,laboratory tests on methane leakage through segment joints were performed.The results show that the leakage process can be divided into“rapid leakage”and“slight leakage”,depending on the leakage pressure and the state of joint deformation.Based on the numerical and experimental analysis results,a relationship between the safety level and the joint deformation is established,which can be used as guidelines for maintaining utility tunnels.