The application of liquid nitrogen injection is an important technique in the field of coal mine fire prevention. However, the mechanism of heat and mass transfer of cryogenic nitrogen in the goaf porous medium has not been well accessed. Hence, the implementation of fire prevention engineering of liquid nitrogen roughly relied on an empirical view. According to the research gap in this respect...

The drift velocity of electrons has been measured in liquid argon and in liquid argon containing nitrogen, oxygen and hydrogen as impurities. It has been found that with nitrogen and hydrogen in solution the drift velocity increases, but that, because of strong electron attachment, inSui3cient oxygen could be added to produce an observable effect. The results support the view that the behaviour...

Cutaneous warts are caused by infection of the epidermis with human papillomavirus (HPV). Cryotherapy using liquid nitrogen is one of the most common local treatments. In this study, we used a novel ex vivo approach to compare the efficacy of a new product with conventional liquid-nitrogen cryotherapy by studying epidermal histology and assessing the presence of HPV types 1 and 2 DNA in plantar...

A study was undertaken to investigate the effect of liquid nitrogen aeration on mortalities of adult Cryptolestes furrugineus, rusty grain beetles, in a prototype cardboard grain bin equipped with an aeration system. The grain bin was filled with Hard Red Spring wheat and liquid nitrogen was introduced from the bottom of the bin. The survival of both cold acclimated and unacclimated C. furrugin...

Preservation of spermatozoa is an important aspect of assisted reproductive medicine. The aim of this study was to investigate the efficacy and use of a recently developed liquid nitrogen and cryogen-free controlled rate freezer and this compared with the classical liquid nitrogen vapour freezing method for the cryopreservation of human spermatozoa. Ten patients entering the IVF programme donat...

Layered methane clouds in Titan’s troposphere with an upper methane ice cloud, a lower liquid methane–nitrogen cloud, and a gap in between were suggested from in situ measurements and ground-based observations. Here we report laboratory investigations under conditions that mimic Titan’s troposphere providing a detailed picture of the cloud layers. A solid methane cloud with a nitrogen content o...

Ti Grade 2 was prepared by cryogenic attritor milling in liquid nitrogen and liquid argon. Two types of milling balls were used—stainless steel balls and heavy tungsten carbide balls. The effect of processing parameters on particle size and morphology, contamination of powder and its microhardness was investigated. Milling in liquid nitrogen was not feasible due to excessive contamination by ni...

To prepare tissues for analysis of NAD(+), NADH, NADP(+), and NADPH, common practice is to freeze samples in liquid nitrogen, often followed by freeze-drying, before extraction in HCl or NaOH. With cucumber (Cucumis sativus L.) cotyledons, prefreezing in liquid nitrogen or slower freezing to -20 degrees C yielded substantially lower values for NADH and NADPH than obtained from samples homogeniz...