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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records

Volatile organic compound detection device

A volatile organic compound collector can include a collector material configured to collect volatile organic compounds given off from a patient's skin; a wrapping configured to isolate the collector material from an external environment; a heater comprising a heating element, the heating element configured to emit a thermal pulse to desorb the volatile organic compounds from the collector material; and a mesh layer configured to prevent the collector material from contacting the patient's skin, wherein the collector material is received between the wrapping and the mesh layer.

Arnold, Gary Stephen↗

Volatile organic compound detection device

A volatile organic compound detection device includes a collector comprising: a collector material configured to collect volatile organic compounds given off from a patient's skin; a heater comprising a heating element, the heating element configured to emit a thermal pulse to desorb the volatile organic compounds from the collector material; and a flow channel configured to receive the volatile organic compounds desorbed by the heater; and a fastener configured to secure the collector to the patient's skin.

Arnold, Gary Stephen↗

Health monitoring device

Example aspects of a volatile organic compound detection device, a wearable health monitoring device, and a method of monitoring a user's health are disclosed. The volatile organic compound detection device can comprise a collector comprising a collector material configured to collect volatile organic compounds given off from a user's skin; a separator comprising a gas chromatography column configured to separate mixtures of the volatile organic compounds into their constituent chemicals; and an identifier comprising a detector and a processor, the detector configured to transduce the constituent chemicals into a signal, the processor configured to process the signal to identify specific volatile organic compounds indicative of a health condition.

42 ENGINEERING↗

Active sampling of volatile chemicals for non-invasive classification of chicken eggs by sex early in incubation

According to industry estimates, approximately 7 billion day-old male chicks are disposed of annually worldwide because they are not of use to the layer industry. A practical process to identify the sex of the egg early in incubation without penetrating the egg would improve animal welfare, reduce food waste and mitigate environmental impact. We implemented a moderate vacuum pressure system through commercial egg-handling suction cups to collect volatile organic compounds (VOCs). Three separate experiments were set up to determine optimal conditions to collect eggs VOCs to discriminate male from female embryos. Optimal extraction time (2 min), storage conditions (short period of incubation during egg storage (SPIDES) at days 8–10 of incubation), and sampling temperature (37.5°C) were determined. Our VOC-based method could correctly differentiate male from female embryos with more than 80% accuracy. These specifications are compatible with the design of specialized automation equipment capable of high-throughput, in-ovo sexing based on chemical sensor microchips.

Borras, Eva↗

Elucidating algal-bacterial community interactions by tracking volatile biomarkers (Final Report)

This feasibility study project aimed to lay further groundwork for studying and understanding how microorganisms interact with each other at the molecular level using model algal-bacterial co-cultures. A better understanding of such interactions is critical to optimizing and operating biotic platforms for a number of applications, including bioenergy, algal bioproducts and agriculture, and carbon capture. Here we explored the feasibility of characterizing and following these interactions by identifying and tracking volatile metabolites and biomarkers in the complex gaseous headspace of such cultures. We set up an experimental platform using a co-culture of Phaeodactylum tricornutum and Marinobacter subspecies 3-2 as a model system, used solid-phase microextraction fibers for volatile collection at various time points throughout culture growth, and employed gas chromatography mass spectrometry-based instrumentation available at LLNL for compound identification and quantification. We found that it is feasible to determine volatile profiles from the growth of Phaeodactylum tricornutum and Marinobacter subspecies 3-2 using our methodology and monitor profile changes over time. We also observed that volatiles distinguishing between cultures of the individual species and the co-cultures could be detected. We expect that results of this project will feed into the ongoing LLNL’s DOE BER funded Biofuels Scientific Focus Area (SFA) on algal-bacterial interactions and pave the way for future expanded volatile studies supported by DOE. The approach and technologies developed here would also be applicable and transferable to other microbial communities under study, such as cyanobacteria, rhizosphere communities and biofilms.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

High temporal resolution generation expansion planning for the clean energy transition

As power systems integrate increasing quantities of wind, solar and energy storage resources, it is important to revisit power system capacity expansion modeling methods and assumptions that have been utilized in thermal- dominated systems. We conduct a series of case study analyses using a simplified representation of the Electric Reliability Council of Texas (ERCOT) system to demonstrate how least-cost capacity expansion outcomes are impacted by changes in model resolution across two temporal dimensions: 1) the number of considered representative periods, and 2) the system dispatch interval. First, we find that the least-cost generation portfolio can differ significantly for small changes in the number of representative days, but largely converges to the 365-day result once 104 representative days are considered. Furthermore, systems with wind, solar and storage resources were more sensitive to changes in the number of representative days than a thermal-dominated system. Second, we find that considering five-minute dispatch resolution consistently results in least-cost generation portfolios with less solar capacity and more energy storage capacity than corresponding scenarios with hourly dispatch intervals. This suggests that hourly dispatch representation fails to capture the intra-hour volatility of solar generation, and therefore also overlooks opportunities for storage resources to provide system value by balancing this volatility. Collectively these results indicate that capacity expansion modelers should revisit conventional approaches to temporal representation when conducting analyses of deeply decarbonized power systems to ensure that such analyses are robust and actionable. To our knowledge, this is the first study to analyze capacity expansion outcomes with five-minute dispatch resolution in this manner.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Seizure detection device

Example aspects of a collector for a seizure detection device, a seizure detection device, and a method of detecting a seizure are disclosed. The collector for a seizure detection device can comprise a collector material configured to collect volatile organic compounds given off from a patient's skin; a wrapping configured to isolate the collector material from an external environment; a heater comprising a heating element, the heating element configured to emit a thermal pulse to desorb the volatile organic compounds from the collector material; and a mesh layer configured to prevent the collector material from contacting the patient's skin, wherein the collector material is received between the wrapping and the mesh layer.

Arnold, Gary Stephen↗

Seizure detection device

A method of detecting a seizure includes collecting volatile organic compounds with a collector material of a collector; separating a mixture of the volatile organic compounds into its constituent chemicals with a gas chromatography column; ionizing the constituent chemicals to create ionized chemicals and detecting the ionized chemicals; and analyzing the ionized chemicals to identify seizure-indicative volatile organic compounds.

Arnold, Gary Stephen↗

Parts per Billion Concentrations of Volatile Organic Gases collected with a PTRMS at the EPCAPE Mount Soledad site from 05-20-2023 to 06-15-2023

This dataset contains the parts per billion concentrations of various volatile organic gases. Data was collected using a Proton Transfer Reaction Mass Spectrometer (PTRMS). Concentrations for all compounds were calculated using a reaction constant (k-value) of 2.0E-9 cm^3/s. On June 14, a calibration was preformed for the gases methanol, acetone, isoprene, butanone, benzene and toluene. Calibrations curves were used to correct the concentrations of these gases. Negative concentration values were replaced with zeros. Other gases were not calibrated for. Data has undergone one minute averaging. Time data is in coordinated universal time (UTC). Time has been recorded in seconds since 1/1/1904.

54 ENVIRONMENTAL SCIENCES↗

DIFFERENTIAL CANID PREDATION OF TRANSLOCATED JUVENILE DESERT TORTOISES AND CHEMICAL SIGNATURE DIFFERENCES BETWEEN FEMALE AND MALE ADULT AND JUVENILE DESERT TORTOISES

Differential predation was observed in a population of 59 translocated juvenile Desert Tortoises (Gopherus agassizii) of known sex during a juvenile translocation survival study between September 2012 and November 2017. The main source of mortality (77%; 24 of 31 deaths) was attributed to Coyote (Canis latrans) and Kit Fox (Vulpes macrotis) predation. Predation was skewed with 71% (n = 17) female mortality versus 29% (n = 7) male mortality. We tested the hypothesis that juvenile females smell different than males which leads to increased canid predation. We also explored differences in chemical signatures of resident adult female and male Desert Tortoises. We collected oral, cloacal and chin/forelimb swabs from translocated juvenile and resident adult female and male tortoises during fall 2015 and fall 2017 and analyzed them using headspace gas chromatography/mass spectrometry to determine potential differences in the chemical signatures among the four groups. Standardized chromatographic peak responses were subjected to repeated analyses of variance (ANOVA). For development of artificial scents, mean responses were calculated for each juvenile tortoise from standardized responses representing all collections (i.e., oral, cloacal, and chin/forelimb swabs) and grand means were determined for males and females. Repeated measures ANOVAs clearly demonstrated that the collections of volatiles differed according to age and/or sex depending on the body location of collection. Among the plausibly endogenous volatiles that differed by age, many of them are alcohols. Two field trials using captive Coyotes and one field trial partially within the translocation area were conducted to test if Coyotes showed a preference for female or bias against male synthesized scent. No consistent preference or bias was shown, suggesting that no innate preference for female odor was evident.

60 APPLIED LIFE SCIENCES↗

The Evolution of Volatile Memory Forensics

The collection and analysis of volatile memory is a vibrant area of research in the cybersecurity community. The ever-evolving and growing threat landscape is trending towards fileless malware, which avoids traditional detection but can be found by examining a system’s random access memory (RAM). Additionally, volatile memory analysis offers great insight into other malicious vectors. It contains fragments of encrypted files’ contents, as well as lists of running processes, imported modules, and network connections, all of which are difficult or impossible to extract from the file system. For these compelling reasons, recent research efforts have focused on the collection of memory snapshots and methods to analyze them for the presence of malware. However, to the best of our knowledge, no current reviews or surveys exist that systematize the research on both memory acquisition and analysis. We fill that gap with this novel survey by exploring the state-of-the-art tools and techniques for volatile memory acquisition and analysis for malware identification. For memory acquisition methods, we explore the trade-offs many techniques make between snapshot quality, performance overhead, and security. For memory analysis, we examined the traditional forensic methods used, including signature-based methods, dynamic methods performed in a sandbox environment, as well as machine learning-based approaches. We summarize the currently available tools, and suggest areas for more research.

Nyholm, Hannah↗

Raw leaf gas exchange data in the Amazon basin, 2014-2016

This data package contains raw leaf gas exchange data used to support the publication "Leaf isoprene and monoterpene emission distribution across hyperdominant tree genera in the Amazon basin," Phytochemistry, in-press. Data was collected from 162 individuals, distributed among 25 botanical families and 113 species, from four sites in the Amazon. The data was collected using a modified portable photosynthesis system for environmental control coupled to a thermal desorption tube for volatile isoprenoid collections. Collected TD tube samples were analysed in Manaus, Brazil, using thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). The dataset includes both photosynthesis and isoprene/monoterpene emission rates from leaves under standard environmental conditions as well as controlled light response curves. For detailed methods and raw data, refer to the publication and related material cited in Dataset References.

54 ENVIRONMENTAL SCIENCES↗

Outgassing of casted and 3D printed silicones

Outgassing of 3D printed and casted silica-filled silicones was studied using a standard ASTM E-595 procedure and a modified Soreq’s method that allows very sensitive measurements of the outgassing kinetics even at low temperatures, 20 – 50 °C. We studied three different silica-filled silicones, non-porous cased M9787, and 3D printed LL50 and 40P materials. The present report shows that vacuum outgassing products of polysiloxane-based materials include multiple species. In addition to chemisorbed and physisorbed water outgassing, previously studied by TPD, polymer fragments of varying sizes evaporate as well. The chemical composition of the condensable volatile species collected on a Germanium substrate, was analyzed by FTIR. It was shown that all studied materials produce mostly PDMS-based outgassing products that form stable droplet-like structure on the Ge substrate. The highest amount of the condensable volatile species was measured for LL50. Isothermal TGA in nitrogen atmosphere of the LL50 material was compared to the standard vacuum outgassing. The results of TGA showed lower mass loss and higher water regain. The kinetics of the outgassing at relatively low temperatures of 20, 30 and 50 °C was studied using Thermoelectric Quartz Crystal Microbalance (TQCM). The TQCM surface was held at -10 °C to enhance condensation of the outgassed moisture. The analysis presented here, when combined with the extensive previous work on moisture outgassing, provides a better understanding of the aging mechanism of polysiloxane-based materials. In this work we show that outgassing techniques, usually applied for qualification of polymers for space-related applications, may be used as a complementary method to study thermal degradation and aging of silica-based silicones. Our results indicate that the long-term degradation mechanics and thermal degradation products depend primarily on the chemical composition of silicone-based material and only slightly affected by the manufacturing process. Surprisingly, the surface-to-volume ratio of the 3D printed vs. casted/molded materials showed only minor effect on the outgassing kinetic parameters.

36 MATERIALS SCIENCE↗

Multivariate regression modelling for gender prediction using volatile organic compounds from hand odor profiles via HS-SPME-GC-MS

The efficacy of using human volatile organic compounds (VOCs) as a form of forensic evidence has been well demonstrated with canines for crime scene response, suspect identification, and location checking. Although the use of human scent evidence in the field is well established, the laboratory evaluation of human VOC profiles has been limited. This study used Headspace-Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry (HS-SPME-GC-MS) to analyze human hand odor samples collected from 60 individuals (30 Females and 30 Males). The human volatiles collected from the palm surfaces of each subject were interpreted for classification and prediction of gender. The volatile organic compound (VOC) signatures from subjects’ hand odor profiles were evaluated with supervised dimensional reduction techniques: Partial Least Squares-Discriminant Analysis (PLS-DA), Orthogonal-Projections to Latent Structures Discriminant Analysis (OPLS-DA), and Linear Discriminant Analysis (LDA). The PLS-DA 2D model demonstrated clustering amongst male and female subjects. The addition of a third component to the PLS-DA model revealed clustering and minimal separation of male and female subjects in the 3D PLS-DA model. The OPLS-DA model displayed discrimination and clustering amongst gender groups with leave one out cross validation (LOOCV) and 95% confidence regions surrounding clustered groups without overlap. The LDA had a 96.67% accuracy rate for female and male subjects. The culminating knowledge establishes a working model for the prediction of donor class characteristics using human scent hand odor profiles.

59 BASIC BIOLOGICAL SCIENCES↗

Low Molecular Weight Volatile Organic Compounds Indicate Grazing by the Marine Rotifer Brachionus plicatilis on the Microalgae Microchloropsis salina

Microalgae produce specific chemicals indicative of stress and/or death. The aim of this study was to perform non-destructive monitoring of algal culture systems, in the presence and absence of grazers, to identify potential biomarkers of incipient pond crashes. Here, we report ten volatile organic compounds (VOCs) that are robustly generated by the marine alga, Microchloropsis salina, in the presence and/or absence of the marine grazer, Brachionus plicatilis. We cultured M. salina with and without B. plicatilis and collected in situ volatile headspace samples using thermal desorption tubes over the course of several days. Data from four experiments were aggregated, deconvoluted, and chromatographically aligned to determine VOCs with tentative identifications made via mass spectral library matching. VOCs generated by algae in the presence of actively grazing rotifers were confirmed via pure analytical standards to be pentane, 3-pentanone, 3-methylhexane, and 2-methylfuran. Six other VOCs were less specifically associated with grazing but were still commonly observed between the four replicate experiments. Through this work, we identified four biomarkers of rotifer grazing that indicate algal stress/death. This will aid machine learning algorithms to chemically define and diagnose algal mass production cultures and save algae cultures from imminent crash to make biofuel an alternative energy possibility.

headspace sampling↗

In Vitro Antimicrobial Activity of Volatile Compounds from the Lichen Pseudevernia furfuracea (L.) Zopf. Against Multidrug-Resistant Bacteria and Fish Pathogens

Lichens are symbiotic organisms with unique secondary metabolism. Various metabolites from lichens have shown antimicrobial activity. Nevertheless, very few studies have investigated the antimicrobial potential of the volatile compounds they produce. This study investigates the chemical composition and antimicrobial properties of volatile compounds from Pseudevernia furfuracea collected in two regions of Morocco. Hydrodistillation was used to obtain volatile compounds from samples collected in the High Atlas and Middle Atlas. Gas chromatography–mass spectrometry (GC-MS) analysis identified phenolic cyclic compounds as the primary constituents, with atraric acid and chloroatranol being the most abundant. Additionally, eight compounds were detected in lichens for the first time. The antimicrobial activity of these compounds was assessed using disc diffusion and broth microdilution methods. Both samples demonstrated significant antimicrobial effects against multidrug-resistant human bacteria, reference microorganisms, fish pathogens, and Candida albicans, with minimum inhibitory concentrations (MICs) ranging from 1000 µg/mL to 31.25 µg/mL. This study provides the first report on the volatile compounds from Pseudevernia furfuracea and their antimicrobial effects, particularly against fish pathogens, suggesting their potential as novel antimicrobial agents for human and veterinary use. Further research is warranted to explore these findings in more detail.

Essadki, Yasser (ORCID:0009000648460075)↗

Size resolved particle volatility for 30, 60, and 90 nm particles collected at the EPCAPE Mount Soledad site from 04/23/2023 to 06/15/2023

VTDMA GF-PDF: Growth factor probability density functions from the Gysel inversion are located here, where probability is out of 200. The instrument measured three different diameters 30 nm, 60nm and 90nm each diameter was selected for an hour. During that hour three different temperatures where scanned (40°C, 80°C, 160°C) in between each temperature a bypass scan was taken at room temperature. Each scan took 10-minutes and scanned growth factors from 0.2-1.2. Calibrations of the instrument with NaCl were performed on 4/26/2023 from 11:20 to 14:20, on 5/16/2023 from 11:40 to 16:00, and on 5/30/2023 from 10:20 to 14:20. Calibrations with (NH4)2SO4 were performed on 5/8/2023 from 11:45 to 14:40, on 5/23/2023 from 11:20 to 3:00, and on 6/14/2023 from 13:00 to 16:00. Time is recorded in seconds since 1/1/1904. GF_Vol_avg: Growth factor volume average calculated by the Gysel inversion. The instrument measured three different diameters 30 nm, 60nm and 90nm each diameter was selected for an hour. During that hour three different temperatures where scanned (40°C, 80°C, 160°C) in between each temperature a bypass scan was taken at room temperature. Each scan took 10-minutes and scanned growth factors from 0.2-1.2. Calibrations of the instrument with NaCl were performed on 4/26/2023 from 11:20 to 14:20, on 5/16/2023 from 11:40 to 16:00, and on 5/30/2023 from 10:20 to 14:20. Calibrations with (NH4)2SO4 were performed on 5/8/2023 from 11:45 to 14:40, on 5/23/2023 from 11:20 to 3:00, and on 6/14/2023 from 13:00 to 16:00. Time is recorded in seconds since 1/1/1904.

30nm growth factor volume average at 160C (GF_vol_↗

TRACER-MAP_2022_volatile_organic_compounds_PTRMS

VOCs collected by quadrupole proton transfer reaction mass spectrometry for July-August 2022. A description of this instrument is included in the related publication. The location of the measurement is indicated by latitude and longitude coordinates; TRACER-MAP included time at the AMF site in La Porte and additional sites around Houston. Data below the minimum detection limit are not included here.

54 ENVIRONMENTAL SCIENCES↗