Storage Of Volatiles Research Articles

Thermoluminescence and Apollo 17 ANGSA Lunar Samples: NASA's Fifty‐Year Experiment and Prospecting for Cold Traps

AbstractBy placing Apollo 17 regolith samples in a freezer, and storing an equivalent set at room temperature, NASA effectively performed a 50‐year experiment in the kinetics of natural thermoluminescence (TL) of the lunar regolith. We have performed a detailed analysis of the TL characteristics of four regolith samples: a sunlit sample near the landing site (70180), a sample 3 m deep near the landing site (70001), a sample partially shaded by a boulder (72320), and a sample completely shaded by a boulder (76240). We find evidence for a total of eight discrete TL peaks, five apparent in curves for samples in the natural state and seven in samples irradiated in the laboratory at room temperature. For each peak, we suggest values for peak temperatures and the kinetic parameters E (activation energy, i.e. “trap depth,” eV) and s (Arrhenius factor, s−1). The lowest natural TL peak in the continuously shaded sample 76240 dropped in intensity by 60 ± 10% (1976 vs. present room temperature samples) and 43 ± 8% (freezer vs. room temperature samples) over the 50‐year storage period, while sunlit and partially shaded samples (70001, 70180, 72321, 72320) showed no change. These results are consistent with the E and s parameters we determined. The large number of peaks, and the appearance of additional peaks after irradiation at room temperature, and literature data, suggest that glow curve peaks are present in lunar regolith at ∼100 K and their intensity can be used to determine temperature and storage time. Thus, a TL instrument on the Moon could be used to prospect for micro‐cold traps capable of the storage of water and other volatiles.

Aphid alarm pheromone mimicry in transgenic Chrysanthemum morifolium: insights into the potential of (E)-β-farnesene for aphid resistance.

(E)-β-Farnesene (EBF) serves as the primary component of the alarm pheromone used by most aphid pest species. Pyrethrum (Tanacetum cinerariifolium) exhibits tissue-specific regulation of EBF accumulation and release, effectively mimicking the aphid alarm signal, deterring aphid attacks while attracting aphid predators. However, cultivated chrysanthemum (Chrysanthemum morifolium), a popular and economically significant flower, is highly vulnerable to aphid infestations. In this study, we investigated the high expression of the pyrethrum EBF synthase (TcEbFS) gene promoter in the flower head and stem, particularly in the parenchyma cells. Subsequently, we introduced the TcEbFS gene, under the control of its native promoter, into cultivated chrysanthemum. This genetic modification led to increased EBF accumulation in the flower stem and young flower bud, which are the most susceptible tissues to aphid attacks. Analysis revealed that aphids feeding on transgenic chrysanthemum exhibited prolonged probing times and extended salivation durations during the phloem phase, indicating that EBF in the cortex cells hindered their host-location behavior. Interestingly, the heightened emission of EBF was only observed in transgenic chrysanthemum flowers after mechanical damage. Furthermore, we explored the potential of this transgenic chrysanthemum for aphid resistance by comparing the spatial distribution and storage of terpene volatiles in different organs and tissues of pyrethrum and chrysanthemum. This study provides valuable insights into future trials aiming for a more accurate replication of alarm pheromone release in plants. It highlights the complexities of utilizing EBF for aphid resistance in cultivated chrysanthemum and calls for further investigations to enhance our understanding of this defense mechanism.

Biochemistry and Genetics of Floral Scent - A Historical Perspective.

Floral scent plays a crucial role in the reproduction process of many plants. Humans have been fascinated by floral scents throughout history, and have transported and traded floral scent products, for which they have found multiple uses as food additives, hygiene and perfume products, and medicines. Yet the scientific study of how plants synthesize floral scent compounds began later than studies on most other major plant metabolites, and the first report of the characterization of an enzyme responsible for the synthesis of a floral scent compound - linalool in Clarkia breweri, a California annual - appeared in 1994. In the almost 30 years since, enzymes and genes involved in the synthesis of hundreds of scent compounds from multiple plant species have been described. This review recapitulates this history and describes the major findings relating to the various aspects of floral scent biosynthesis and emission, including genes and enzymes and their evolution, storage and emission of scent volatiles, and the regulation of the biochemical processes.

Nanorocks, volatiles and plate tectonics

The global geological volatile cycle (H, C, N) plays an important role in the long term self-regulation of the Earth system. However, the complex interaction between its deep, solid Earth components (i.e. crust and mantle), Earth’s fluid envelopes (i.e. atmosphere and hydrosphere) and plate tectonic processes is a subject of ongoing debate. In this study we want to draw attention to how the presence of primary melt (MI) and fluid (FI) inclusions in high-grade metamorphic minerals could help constrain the crustal component of the volatile cycle. To that end, we review the distribution of MI and FI throughout Earth’s history, from ca. 3.0 Ga ago up to the present day. We argue that the lower crust might constitute an important, long-term, volatile storage unit, capable to influence the composition of the surface envelopes through the mean of weathering, crustal thickening, partial melting and crustal assimilation during volcanic activity. Combined with thermodynamic modelling, our compilation indicates that periods of well-established plate tectonic regimes at <0.85 Ga and 1.7–2.1 Ga, might be more prone to the reworking of supracrustal lithologies and the storage of volatiles in the lower crust. Such hypothesis has implication beyond the scope of metamorphic petrology as it potentially links geodynamic mechanisms to habitable surface conditions. MI and FI in metamorphic crustal rocks then represent an invaluable archive to assess and quantify the co-joint evolution of plate tectonics and Earth’s external processes.

Long-term storage of subduction-related volatiles in Northern Victoria Land lithospheric mantle: Insight from olivine-hosted melt inclusions from McMurdo basic lavas (Antarctica)

H2O, CO2, F, Cl and S concentrations in olivine-hosted melt inclusions (MI) from Cenozoic alkaline volcanics of Northern Victoria Land (NVL, Antarctica) were determined by Secondary Ion Mass Spectrometry (SIMS). The most undegassed H2O and CO2 values varies from 1.14 to 2.64 wt% H2O and from 2320 to 3900 ppm CO2 for the least differentiated alkaline basalts and basanites, respectively. The same MI have F and Cl contents varying from 471 to 888 and from 474 to 1135 respectively, although some other MI can get up to 1377 of F and 1336 of Cl. A H2O/(H2O + CO2) molar ratios from 0.88 to 0.92 were determined, and taking into account the MI with the highest water content, a CO2 content in the melts up to 4400 and 8800 ppm for basaltic and basanitic compositions were inferred. Assuming that these magmas were produced by about 3 to 7% of partial melting, the volatile content in the mantle sources were estimated and compared with the estimates obtained from amphibole-bearing mantle xenoliths abundantly entrained in the McMurdo basic lavas. The two approaches converge in obtaining the following values: H2O = 1160 ± 436 ppm; CO2 = 304 ± 64 ppm. Some discrepancies are observed for F and Cl, mainly due to the uncertainties in the F and Cl contents of amphibole and its modal content, both parameters spanning a rather large range.The resulting CO2/Nb and CO2/Ba ratios are lower and H2O/Ce higher than those estimated for Depleted MORB Mantle (DMM), suggesting that the NVL Cenozoic alkaline magmatism could be originated by an enriched mantle source composed by 60 to 70% Enriched Mantle (EM) and from 40 to 30% DMM.A global comparison of fluid-related, highly incompatible and immobile/low incompatible elements such as Li, K, Cl, Ba, Nb, Dy and Yb allow to put forward that the prolonged (~500 to 100 Ma) Ross subduction event played a fundamental role in providing the volatile budget to the lithospheric mantle before the onset of the Cenozoic continental rifting.

Mixed incorporation of carbon and hydrogen in silicate melts under varying pressure and redox conditions

Volatiles including carbon and hydrogen are generally considered to be more soluble in silicate melts than in mantle rocks. How these melts contribute to the storage and distribution of key volatiles in Earth's interior today and during its early evolution, however, remains largely unknown. It is essential to improve our knowledge about volatiles-bearing silicate magmas over the entire mantle pressure regime. Here we investigate molten Mg1−xFexSiO3 (x=0, 0.25) containing both carbon and hydrogen using first-principles molecular dynamics simulations. Our results show that the dissolution mechanism of the binary volatiles in melts varies considerably under different conditions of pressure and redox. When incorporated as CO2 and H2O components (corresponding to oxidizing conditions) almost all carbon and hydrogen form bonds with oxygen. Their speciation at low pressure consists of predominantly isolated molecular CO2, carbonates, and hydroxyls. More oxygenated species, including tetrahedrally coordinated carbons, hydrogen (O-H-O) bridges, various oxygen-joined complexes appear as melt is further compressed. When two volatiles are incorporated as hydrocarbons CH4 and C2H6 (corresponding to reducing conditions), hydroxyls are prevalent with notable presence of molecular hydrogen. Carbon-oxygen bonding is almost completely suppressed. Instead carbon is directly correlated with itself, hydrogen, and silicon. Both volatiles also show strong affinity to iron. Reduced volatile speciation thus involves polymerized complexes comprising of carbon, hydrogen, silicon, and iron, which can be mostly represented by two forms: C1−4H1−5Si0−5O0−2 (iron-free) and C5−8H1−8Si0−6Fe5−8O0−2. The calculated partial molar volumes of binary volatiles in their oxidized and reduced incorporation decrease rapidly initially with pressure and then gradually at higher pressures, thereby systematically lowering silicate melt density. Our assessment of the calculated opposite effects of the volatile components and iron on melt density indicates that melt-crystal density crossovers are possible in the present-day mantle and also could have occurred in early magma ocean environments. Melts at upper mantle and transition zone conditions likely dissolve carbon and hydrogen in a wide variety of oxidized and non-oxygenated forms. Deep-seated partial melts and magma ocean remnants at lower mantle conditions may exsolve carbon as complex reduced species possibly to the core during core-mantle differentiation while retaining a majority of hydrogen as hydroxyls-associated species.

Structures related to pheromone storage in alar androconia and the female abdominal scent gland of Heliconius erato phyllis, Heliconius ethilla narcaea, and Heliconius besckei (Lepidoptera: Nymphalidae: Heliconiinae).

We describe the morphology of alar androconia and the female abdominal scent gland of Heliconius erato phyllis, Heliconius ethilla narcaea, and Heliconius besckei. Androconial scales of Heliconius, which are arranged in overlapping wing bands, release pheromones during courtship, probably through vibratory movements of male wings over the female to induce her to mate. An antiaphrodisiac is produced by glands located in the valves of the male and is transferred during copulation to the yellow dorsal abdominal sac present in the virgin female, causing this sac to emit a scent that reduces the attractiveness of the female for courtship with other males. Stereomicroscopy, SEM, and TEM analyses were conducted to describe the morphology of the internal and external scales and the external abdominal scent sac. The findings revealed different sizes of external androconial scales and an internal group of porous structural vesicles that are probably related to the preservation of internal space, reception and storage of secretions, and elimination of volatiles when the male is actively involved in courtship. Translucent projections on the female abdominal scent sac create open reservoirs for the reception, storage, and emission of antiaphrodisiac volatiles along with stink clubs. Male valve denticles vary in form and probably attach securely to the female sac during mating, thus ensuring secretion transfer. These features are discussed in the context of a comparative analysis.

Biomass-based negative emission technology options with combinedheat and power generation

Biomass-based combined heat and power (CHP) generation with differentcarbon capture approaches is investigated in this study. Only direct carbon dioxide(CO2) emissions are considered. The selected processesare (i) a circulating fluidized bed boiler for wood chips connected to anextraction/condensation steam cycle CHP plant without carbon capture; (ii) plant(i), but with post-combustion CO2 capture; (iii) chemicallooping combustion (CLC) of solid biomass connected to the steam cycle CHP plant;(iv) rotary kiln slow pyrolysis of biomass for biochar soil storage and directcombustion of volatiles supplying the steam cycle CHP plant with theCO2 from volatiles combustion escaping to the atmosphere;(v) case (iv) with additional post-combustion CO2 capture;and (vi) case (iv) with CLC of volatiles. Reasonable assumptions based on literaturedata are taken for the performance effects of the CO2 capturesystems and the six process options are compared. CO2compression to pipeline pressure is considered. The results show that both bioenergywith carbon capture and storage (BECCS) and biochar qualify as negative emissiontechnologies (NETs) and that there is an energy-based performance advantage of BECCSover biochar because of the unreleased fuel energy in the biochar case. Additionalaspects of biomass fuels (ash content and ash melting behavior) and sustainable soilmanagement (nutrient cycles) for biomass production should be quantitativelyconsidered in more detailed future assessments, as there may be certain biomassfuels, and environmental and economic settings where biochar application to soils isindicated rather than the full conversion of the biomass to energy andCO2.

A comparison of postharvest physiology, quality and volatile compounds of ‘Fuji’ and ‘Delicious’ apples inoculated with Penicillium expansum

Blue mold caused by Penicillium expansum is a major postharvest disease of apple fruit, which leads to fruit loss and patulin accumulation. In this study, ‘Delicious’ and ‘Fuji’ apples were inoculated with P. expansum to investigate effects of infection on physiology, quality and release of volatile compounds. The results showed that P. expansum significantly promoted ethylene production, increased respiration rate, and induced higher peaks of ethylene and respiration in fruit. The fungus also caused a lower of membrane integrity, firmness, and the content of total soluble solid and titratable acid. Moreover, P. expansum increased the content of volatile compounds in two cultivars of apple. C6 alcohol and aldehyde contents were significantly improved by inoculation in the earlier storage stage, and ester contents were improved in the middle and later storage stage. According to PLS-DA analysis, hexanoic acid and hexanal were the most important factors to distinguish the inoculated ‘Delicious’ and ‘Fuji’ from their controls. Interestingly, among specific volatile compounds detected in the two inoculated cultivars, 3 volatile compounds, including phenethyl acetate, methyl 2-methylbutanoate and ethyl benzeneacetate, were common in both of inoculated fruit. Although wounding increased ethylene production and respiration rate, decreased quality of the two cultivars and affected volatiles release, the effects were less than P. expansum. Compared with ‘Fuji’, the inoculated ‘Delicious’ had a higher of lesion diameter, ethylene production and respiration rate and content of total soluble solid, and a lower of membrane integrity, firmness and content of titratable acid. The inoculated ‘Delicious’ also released more volatile compounds, especially C6 volatiles. In general, P. expansum inoculation promoted ripening and quality loss, leading to change of volatile compounds during storage and release of specific volatiles. Moreover, ‘Delicious’ was more susceptible to P. expansum than ‘Fuji’.

Melt inclusion evidence for CO2-rich melts beneath the western branch of the East African Rift: implications for long-term storage of volatiles in the deep lithospheric mantle

We present new major element, trace element, and volatile (H2O, CO2, S, F, and Cl) concentrations of olivine-hosted melt inclusions from five high-K, low-silica basanites from the western branch of the East African Rift System and use these data to investigate the generation of H2O- and CO2-rich melts at up to ~150 km depth. Measured H2O and CO2 concentrations reach ~2.5 and ~1 wt%, respectively, representing some of the highest CO2 concentrations measured in a melt inclusion to date. These measurements represent direct evidence of the high CO2 and H2O concentrations required to generate high-K alkaline lavas, and the CO2 that has been previously inferred to be necessary for the low mantle potential temperatures in the area. Ratios of CO2/Nb, CO2/Ba, and CO2/Cl are used to estimate an initial melt CO2 concentration of 5–12 wt%. The measured CO2 concentrations are consistent with CO2 solubilities determined by molecular dynamics calculations and high-pressure experiments for melt generation at 3–6 GPa; the depth of melting suggested by previous studies in the area. These melt inclusions measurements represent direct evidence for the presence of H2O- and CO2-rich melts in the deep upper mantle that have been proposed based on experimental and seismic evidence. Primitive-mantle normalized trace element patterns more closely resemble those found in subduction settings rather than ocean island basalt, and ratios of slab fluid tracers such as Li/Dy and B/Be indicate that the measured volatile abundances may be related to Neoproterozoic subduction during the assembly of Gondwana, implying the storage of volatiles in the mantle by subduction-related metasomatism.

Bio-inspired surfactants capable of generating plant volatiles.

Plants are able to synthesize, store and release lipophilic organic molecules known as plant volatiles (PVs) utilizing specific biological pathways and different enzymes which play vital roles in the plant's defence and in dealing with biotic and abiotic stress situations. The process of generation, storage and release of PVs by plants acquired during the course of evolution is a very complex phenomenon. Bio-inspired molecular design of farnesol-based surfactants facilitates similar production, storage and release of PVs. The designed molecules adsorb at air-water interface and self-aggregate into micelles in aqueous system. The structural design of the molecules allows them to self-activate in water via intramolecular cation-π interactions. The activated molecules undergo molecular rearrangements generating volatile organic molecules both at interface and inside the micelle core. The molecules adsorbed at the interface initially release the formed volatile molecules creating vacant space at interface, thus thermodynamically directing the micelle to release the manufactured volatile products.

Bidirectional exchange of biogenic volatiles with vegetation: emission sources, reactions, breakdown and deposition

Biogenic volatile organic compound (BVOC) emissions are widely modelled as inputs to atmospheric chemistry simulations. However, BVOC may interact with cellular structures and neighbouring leaves in a complex manner during volatile diffusion from the sites of release to leaf boundary layer and during turbulent transport to the atmospheric boundary layer. Furthermore, recent observations demonstrate that the BVOC emissions are bidirectional, and uptake and deposition of BVOC and their oxidation products are the rule rather than the exception. This review summarizes current knowledge of within-leaf reactions of synthesized volatiles with reactive oxygen species (ROS), uptake, deposition and storage of volatiles, and their oxidation products as driven by adsorption on leaf surface and solubilization and enzymatic detoxification inside leaves. The available evidence indicates that because of the reactions with ROS and enzymatic metabolism, the BVOC gross production rates are much larger than previously thought. The degree to which volatiles react within leaves and can be potentially taken up by vegetation depends upon compound reactivity, physicochemical characteristics, as well as upon their participation in leaf metabolism. We argue that future models should be based upon the concept of bidirectional BVOC exchange and consider modification of BVOC sink/source strengths by within-leaf metabolism and storage.

Cryogenics for lunar exploration

As part of the refocusing of NASA from Space Station research to exploration research, we are pursuing a number of proposed and funded projects for lunar exploration using cryogenic techniques. This paper gives a summary of these projects which include: (1) Using passive radiative cooling for separation and storage of volatiles from lunar regolith; (2) Studies of boiling and two-phase flow under lunar gravity; (3) SQUID-based MRI for monitoring astronaut health; (4) Studies of volatiles and water ice in permanently shadowed craters at the lunar poles; and (5) Seismic search for strange quark matter using the Moon as a large and seismically quiet detector.

A method for collection, long-term storage, and bioassay of labile volatile chemosignals

A procedure for headspace sampling and long-term storage of organic volatiles coupled with gas chromatographic-mass spectrometric (GC-MS) analysis was used to study the volatile chemosignals in a biological secretion prior to bioassay. The approach involved collecting the volatiles in evacuated canisters from an apparatus in which 1 ml of secretion was dispersed for headspace sampling. These canisters, stainless steel, 850 ml, and 100% internally electropolished, have been demonstrated to store volatile compounds, in chemically stable form, for several weeks. The GC-MS analyses provided the quantitation and identification of compounds from C3 through C14 at concentrations as low as 0.10 parts per billion volume. The approach was used to study chemosignals of musth temporal gland secretions (TGS) from a male Asian elephant (Elephas maximus). Fresh TGS material loses its biological activity within 1 hr. TGS material stored at -20°C usually looses its activity within 30 days. The usefulness of this method for long-term storage of the volatile chemosignals was demonstrated by the retention of biologically active TGS headspace compounds, as determined through bioassays, stored in these canisters for one year.

A first look at atmospheric dynamics and temperature variations on Titan

Pollack (1973) has used a radiative equilibrium model to match radiometric data for Titan and infers the atmospheric mass, composition, opacity, and gross vertical thermal structure. These results are used to estimate the atmospheric temperature variations by means of scaling analysis, taking into account dynamics both for a baroclinic wave regime and for an axially symmetric circulation regime. Horizontal temperature variations of the atmosphere and surface are found to be very small, and the circulation is found to be weak and probably axially symmetric. The small temperature variations appear to preclude the storage of volatiles in polar caps, so that the present atmospheric methane content may be due to a balance between outgassing and photodissociation.