Most of the expressions describing fire plumes reported in the literature are known to be based on experiments. Due to different experimental methods, the geometry of the fire sources, fuel types and surrounding condi...Most of the expressions describing fire plumes reported in the literature are known to be based on experiments. Due to different experimental methods, the geometry of the fire sources, fuel types and surrounding conditions, it is difficult to derive a comprehensive picture of a plume with its temperature and velocity fields on the basis of existing theoretical work. Computational Fluid Dynamics （CFD）, which is regarded as a practical engineering tool in fire engineering by the experts, is sure to be able to give more details of the plume behavior under various situations. Aerodynamics for thermally-induced plumes will be studied numerically with CFD. Four typical axisymmetric plume equations will be assessed in this paper, and investigations will be useful for fire engineers in designing smoke management systems in an affordable fashion. This is a critical point in implementing engineering performance-based fire code.展开更多
OBJECTIVE: To evaluate the effects that inhalation of the combustion products of the traditional Chinese herb Aiye(Folium Artemisiae Argyi) has on the central nervous system.METHODS: Forty Kunming mice(half male) were...OBJECTIVE: To evaluate the effects that inhalation of the combustion products of the traditional Chinese herb Aiye(Folium Artemisiae Argyi) has on the central nervous system.METHODS: Forty Kunming mice(half male) were randomly assigned(n = 10/group) to a control group(C) or one of three moxa smoke concentration groups(% opacity): low(L1; 0.4%), medium(M1; 2%), and high(H1; 15%). Mice in the latter three groups were exposed to moxa smoke in a dynamic gas exposure cabinet for 20 min per day for7 days. Mice in control group were placed in the same cabinet without any intervention. For the sleep experiments, another 50 mice were divided into five groups of 10 mice each: a saline-injected control group, L1 + pentobarbital sodium(PS)-injected group, M1+PS group, H1(15%)+PS group,and a positive control group(10 mg/kg, chlorpromazine, p.o.). The weight, general activities, locomotor activities, rotarod performance, sleep duration,and sleeping rate induced by a subthreshold dose of pentobarbital sodium were recorded in the mice,and the composition of moxa smoke was analyzed using headspace gas chromatography(GC-HS).RESULTS: A low concentration of smoke significantly decreased the frequency of locomotor activities and the time for which the mice remaining on the rotarod; however, a high smoke concentration significantly prolonged the pentobarbital-induced sleeping time and sleeping rate.CONCLUSION: The concentration-dependent relaxing effects of moxa smoke on the Central Nervous System(CNS) were confirmed. Moreover, GC-HS analysis showed that the component present in the highest concentration in moxa smoke was eucalyp-tol, an essential oil well recognized for its soothing effects on the CNS. This may therefore be accountable for the sedative effects of moxa smoke.展开更多
文摘Most of the expressions describing fire plumes reported in the literature are known to be based on experiments. Due to different experimental methods, the geometry of the fire sources, fuel types and surrounding conditions, it is difficult to derive a comprehensive picture of a plume with its temperature and velocity fields on the basis of existing theoretical work. Computational Fluid Dynamics （CFD）, which is regarded as a practical engineering tool in fire engineering by the experts, is sure to be able to give more details of the plume behavior under various situations. Aerodynamics for thermally-induced plumes will be studied numerically with CFD. Four typical axisymmetric plume equations will be assessed in this paper, and investigations will be useful for fire engineers in designing smoke management systems in an affordable fashion. This is a critical point in implementing engineering performance-based fire code.
基金Supported by the National Natural Science Foundation of China:Effect of Moxibustion on"Longevity Gene"SIRT1 Regulation in Aged Mice(No.81403449)NSFC Project:Effect of Moxibustion and its Therapeutic Factors on Mitochondrial Energy Metabolism and Apotosis Pathyway in APP/PS1Transgenic Alzheimer's Disease Mouse Model(No.81574068)National Program on Key Basic Research Project(973 Program):the Study of Components and Mechanisms of Artemisia and the Product and Moxibustion and Safety Evaluation(No.2009CB522906)
文摘OBJECTIVE: To evaluate the effects that inhalation of the combustion products of the traditional Chinese herb Aiye(Folium Artemisiae Argyi) has on the central nervous system.METHODS: Forty Kunming mice(half male) were randomly assigned(n = 10/group) to a control group(C) or one of three moxa smoke concentration groups(% opacity): low(L1; 0.4%), medium(M1; 2%), and high(H1; 15%). Mice in the latter three groups were exposed to moxa smoke in a dynamic gas exposure cabinet for 20 min per day for7 days. Mice in control group were placed in the same cabinet without any intervention. For the sleep experiments, another 50 mice were divided into five groups of 10 mice each: a saline-injected control group, L1 + pentobarbital sodium(PS)-injected group, M1+PS group, H1(15%)+PS group,and a positive control group(10 mg/kg, chlorpromazine, p.o.). The weight, general activities, locomotor activities, rotarod performance, sleep duration,and sleeping rate induced by a subthreshold dose of pentobarbital sodium were recorded in the mice,and the composition of moxa smoke was analyzed using headspace gas chromatography(GC-HS).RESULTS: A low concentration of smoke significantly decreased the frequency of locomotor activities and the time for which the mice remaining on the rotarod; however, a high smoke concentration significantly prolonged the pentobarbital-induced sleeping time and sleeping rate.CONCLUSION: The concentration-dependent relaxing effects of moxa smoke on the Central Nervous System(CNS) were confirmed. Moreover, GC-HS analysis showed that the component present in the highest concentration in moxa smoke was eucalyp-tol, an essential oil well recognized for its soothing effects on the CNS. This may therefore be accountable for the sedative effects of moxa smoke.
