Liquid Nitrogen

Several critical variables associated with successful cryopreservation of oyster embryos (Crassostrea gigas) were examined. These were 1) embryo developmental stage, 2) kind and concentration of cryoprotectant, 3) equilibration time, and 4) freezing rate. The percentage of survival was scored as the number of recovered embryos that swam actively 12 h after thawing and had developed into veliger stage. The oyster

The results of investigation of the spectral characteristics of radiation in the presence of the photonic flame effect recently discovered experimentally are presented. Radiation from a ruby laser operating in the Q-factor modulation regime with a generation wavelength of 694.3 nm is focused near the oriented surface of a globular photon crystal (artificial opal with a globule size of 230 nm) placed on a copper cold guide whose temperature is close to the liquid-nitrogen boiling point (77 K). The spectrum of long-term afterglow (with a duration of about several seconds when the duration of a pump pulse is equal to 20 ns) appearing in the photonic flame effect is detected using a fiber optic minispectrometer and consists of several comparatively narrow lines whose intensity strongly varies with the pumping power. A similar glow is observed in opal samples filled with acetone or ethanol.

By internal oxidation of AgMg- and PdMg-alloys small precipitates ofMgO are formed within the Ag- or Pd-matrix. Thetotal area of the metal/oxide interface produced this way becomes severalsquare meters in one cubic centimeter of metal. Segregation of oxygen at theinterface is determined by desorption of gaseous oxygen for theAg/MgO-interface and by trapping of hydrogen for the Pd/MgO-interface. At673 to 873

To remove the environmental and safety hazards associated with power transformers, the authors have investigated the use of liquid nitrogen as a replacement for transformer oil. This paper details tests performed to determine new design rules and efficiency expectations of liquid nitrogen filled power transformers (Enviro-Transformers). The tests include dielectric strength testing of liquid nitrogen and mechanical strength testing of

Pollination effectiveness was evaluated for pollen (pollinia) from two Dendrobium hybrids, ‘Sena Red’ and ‘Mini WRL’, submitted to cryopreservation using a vitrification protocol. Parameters evaluated included pollinia exposure to a previtrification solution (PVS2) under ice (0 °C) or room (27 ± 2 °C) temperatures from 1 to 4 hours before cryopreservation (LN). On removal from cryopreservation, pollinia were used to pollinate flowers of the same hybrids to verify viability and germination. All pollinia showed high percentages of germination (greater than 80%) after crosses were performed, except for pollinia from Dendrobium ‘Sena Red’ submitted to 3 hours of precooling (0 °C) in PVS2 followed by LN (60%) and for pollinia submitted to PVS2 for 3 hours at room temperature with no precooling (70%). Capsules were formed for both hybrids and seeds were successfully produced. The seed viability test revealed high viability (90% to 95%) for all treatments for both hybrids. Seeds observed u...

We have studied two samples of synthetic sapphire. Sample 1 was used as a window in a cryostat and was subjected to liquid nitrogen temperature for a long time (two years). Sample 2 was stored at room temperature. Under identical conditions, three types of Raman spectra were measured on Sample 1 in the wave number range 100–800cm−1. In the spectra

We have optimized a simple and rapid method for isolating milligram quantities of high quality DNA from polysaccharide- and polyphenolic-rich tissue such as sugarcane, lettuce and strawberry. The protocol utilizes fresh tissue without making use of liquid nitrogen or freeze-drying for initial grinding of the tissue and it significantly minimize the use of lab materials. At least one hundred samples can be processed daily by one person. The isolated DNA is essentially free of polysaccharides, polyphenols, RNA and other major contaminants, as judged by: its clear color, its viscosity, A260/A280 ratio, digestibility with restriction enzymes, and suitability for Restriction Fragment Length Polymorphism (RFLP)- and Polymerase Chain Reaction (PCR)-based techniques.

The present work was aimed to study the effect of various grinding agents and detergents on the amount and purity of
the extracted DNA from diverse plant samples. Agents supporting grinding process were liquid nitrogen, acid washed
sand and glass beads, along with a number of concentrations of two detergents i.e. SDS (Sodium Dodecyl Sulphate)
and CTAB (Cetyltrimethylammonium bromide). Six plants species Croton (Codiaeum variegatum), Tomato
(Lycopersicon esculentum), Orchid (Orchis militaris), Date palm (Phoenix dactylifera L.), Pineapple (Ananas
cosmosus) and Aloe (Aloe vera); were selected for DNA isolation and these plant species differ in their leaf texture as
well as polysaccharides and phenolics content. The results obtained showed the presence of linear relationship between
detergent and yield of the DNA with a little influence on the purity. The type of grinding agent did not significantly
affect the purity of the extracted DNA but the amount of extracted DNA is greatly influenced. The purest DNA samples
of all six plants species were selected and subjected to PCR amplification.

While microspheres have been recognized as a legitimate insulation material for decades, actual use in full-scale cryogenic storage tanks has not been demonstrated until now. The performance and life-cycle-cost advantages previously predicted have now been proven. Most bulk cryogenic storage tanks are insulated with either multilayer insulation (MLI) or perlite. Microsphere insulation, consisting of hollow glass bubbles, combines in a single material the desirable properties that other insulations only have individually. The material has high crush strength, low density, is noncombustible, and performs well in soft vacuum. These properties were proven during recent field testing of two 22,700-L (6,000-gallon) liquid nitrogen tanks, one insulated with microsphere insulation and the other with perlite. Normal evaporation rates (NER) for both tanks were monitored with precision test equipment and insulation levels within the tanks were observed through view ports as an indication of in...

The USDA-ARS National Clonal Germplasm Repository (NCGR) stores the global diversity of Humulus for the US Plant Germplasm System as trellised plants in a field genebank. In vitro storage and cryopreservation are now considered excellent ways to provide medium and long-term storage for plant collections. Developing a new cryopreservation or cold storage protocol for every accession or genus of large multi-crop collections can be a very time consuming and long-term activity. We propose that standard cold storage and cryopreservation techniques used for other temperate crop genera would be successful for additional crops with few modifications. This study was initiated to determine if a large collection of hops germplasm could be successfully stored with techniques developed for unrelated genera. In this study we characterized the response of diverse Humulus genotypes to in vitro storage under low light at 4 degree C following techniques used for strawberry and mint plants, and cryopr...