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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 1,045 records · Page 58
All sourcesNASA NTRSDOE OSTI
DOE OSTI2013

Exposure to pyrethroids insecticides and serum levels of thyroid-related measures in pregnant women

Possible association between environmental exposure to pyrethroid insecticides and serum thyroid-related measures was explored in 231 pregnant women of 10–12 gestational weeks recruited at a university hospital in Tokyo during 2009–2011. Serum levels of free thyroxine (fT4), thyroid stimulating hormone (TSH) and thyroid biding globulin (TBG) and urinary pyrethroid insecticide metabolite (3-phenoxybenzoic acid, 3-PBA) were measured. Obstetrical information was obtained from medical records and dietary and lifestyle information was collected by self-administered questionnaire. Geometric mean concentration of creatinine-adjusted urinary 3-PBA was 0.363 (geometric standard deviation: 3.06) μg/g cre, which was consistent with the previously reported levels for non-exposed Japanese adult females. The range of serum fT4, TSH and TBG level was 0.83–3.41 ng/dL, 0.01–27.4 μIU/mL and 16.4–54.4 μg/mL, respectively. Multiple regression analysis was carried out by using either one of serum levels of thyroid-related measures as a dependent variable and urinary 3-PBA as well as other potential covariates (age, pre-pregnancy BMI, parity, urinary iodine, smoking and drinking status) as independent variables: 3-PBA was not found as a significant predictor of serum level of thyroid-related measures. Lack of association may be due to lower pyrethroid insecticide exposure level of the present subjects. Taking the ability of pyrethroid insecticides and their metabolite to bind to nuclear thyroid hormone (TH) receptor, as well as their ability of placental transfer, into consideration, it is warranted to investigate if pyrethroid pesticides do not have any effect on TH actions in fetus brain even though maternal circulating TH level is not affected. -- Highlights: • Pyrethroid exposure and thyroid hormone status was examined in pregnant women. • Urinary 3-phenoxybenzoic acid was used as a biomarker of exposure. • Iodine nutrition, age and other covariates were included in statistical models. • No association was found between levels of thyroid hormone and pyrethroid exposure. • The result may be ascribed to lower exposure level.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2014

Exposure to mercury among Spanish preschool children: Trend from birth to age four

The purpose of this study is to describe the total hair mercury concentrations and their determinants in preschool Spanish children, as well as to explore the trend in mercury exposure from birth to the age four. This evolution has been scarcely studied in other birth cohort studies. The study population was 580 four year old children participating in the INMA (i.e. Childhood and Environment) birth cohort study in Valencia (2008–2009). Total mercury concentration at age four was measured in hair samples by atomic absorption spectrometry. Fish consumption and other covariates were obtained by questionnaire. Multivariate linear regression models were conducted in order to explore the association between mercury exposure and fish consumption, socio-demographic characteristics and prenatal exposure to mercury. The geometric mean was 1.10 µg/g (95%CI: 1.02, 1.19). Nineteen percent of children had mercury concentrations above the equivalent to the Provisional Tolerable Weekly Intake proposed by WHO. Mercury concentration was associated with increasing maternal age, fish consumption and cord blood mercury levels, as well as decreasing parity. Children whose mothers worked had higher mercury levels than those with non working mothers. Swordfish, lean fish and canned fish were the fish categories most associated with hair mercury concentrations. We observed a decreasing trend in mercury concentrations between birth and age four. In conclusion, the children participating in this study had high hair mercury concentrations compared to reported studies on children from other European countries and similar to other countries with high fish consumption. The INMA study design allows the evaluation of the exposure to mercury longitudinally and enables this information to be used for biomonitoring purposes and dietary recommendations. - Highlights: • The geometric mean of hair Hg concentrations was 1.10 µg/g. • 19% of children had Hg concentrations above the RfD proposed by the WHO. • Hair Hg concentrations in children increased as a function of total fish intake. • Swordfish, lean fish and canned fish were the most related to Hg concentrations. • There was a decrease in Hg concentrations from birth to age four.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2015

Anthroposophic lifestyle influences the concentration of metals in placenta and cord blood

Allergic diseases develop in genetically susceptible individuals in a complex interplay with the environment, usually early in life. We have previously shown that the anthroposophic lifestyle is associated with reduced risk of allergic disease in children, but details on the influencing environmental factors are largely unknown. This study aims to elucidate if anthroposophic lifestyle influences fetal exposure to selected toxic and essential elements. Randomly selected non-smoking mothers with (n=40) and without (n=40) anthroposophic lifestyle from the prospective birth cohort ALADDIN were included. Concentrations of 12 toxic and essential elements were analyzed in full term placentas and in the erythrocyte fractions of maternal peripheral blood and of umbilical cord blood, using inductively coupled plasma mass spectrometry. Cadmium concentrations in maternal blood and placenta were significantly higher in mothers with an anthroposophic lifestyle (p<0.001), while concentrations in cord blood were generally low, irrespective of lifestyle. Cobalt concentrations were higher in both maternal blood, placenta and cord blood in the anthroposophic group. Lead concentrations were higher in maternal blood and cord blood, but not placenta, of mothers with anthroposophic lifestyle. Analysis of covariance, including lifestyle, parity, maternal age, gestational age, vegetarian diet, use of herbal medicine and occupation in the model, showed that mainly the anthroposophic lifestyle was significantly associated with cadmium concentrations. In conclusion, women with an anthroposophic lifestyle had higher concentrations of cadmium, cobalt and lead concentrations. Cadmium concentrations might have been influenced by a diet rich in vegetables and/or low iron status of the mothers. - Highlights: • Toxic elements in mother–newborn pairs in relation to anthroposophic lifestyle. • Anthroposophic lifestyle was associated with higher levels of cadmium, cobalt and lead. • A diet rich in vegetables and/or low iron status may explain observed findings. • Nine other elements showed no differences by lifestyle.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Organochlorine pesticides and polychlorinated biphenyls in human adipose tissue from northern Tunisia: Current extent of contamination and contributions of socio-demographic characteristics and dietary habits

The aims of the present study were to investigate the current exposure levels of persistent organochlorine compounds (OCs) in adipose tissues intraoperatively collected from 40 patients over 20 years undergoing non-cancer-related surgery residing in Northern region of Tunisia (Bizerte), which constitutes an exemplary case, and examined association between levels of contamination and both socio-demographic characteristics and dietary habits. Concentration of hexachlorobenzene (HCB), hexachlorocyclohexane isomers (α-HCH, β-HCH, γ-HCH and δ-HCH), dichlorodiphenyltrichloroethane isomers (p,p′-DDT and o,p′-DDT) and metabolites (p,p′-DDE, o,p′-DDE, p,p′-DDD and o,p′-DDD) and 12 polychlorinated biphenyls (PCBs) congeners were measured using capillary gas chromatography with electron capture detector. Overall, residue levels of OCs followed the decreasing order of DDTs > PCBs > HCB > HCHs. DDTs levels ranged from 74.49 to 1834.76 ng g{sup −1} lipid and contributing to more than 90% to the sum of organochlorine pesticides (OCPs). p,p′-DDE was the most abundant in all samples and the p,p′-DDT/p,p′-DDE ratio (range between 1.85% and 58.45%) suggesting recent and ongoing exposure to banned commercial DDT products. PCB concentrations varied from 29.27 to 322.58 ng g{sup −1} lipid and PCB-180, PCB-153 and PCB-138 were the dominant congeners accounting for 70% of total PCBs. We did not find significant correlations between OC exposure levels and sex, parity, habitat areas and smoking habits. In females, the adipose tissue concentrations of DDTs, HCB and PCB-118 were positively correlated with age. There was statistically significant relationship between body mass index (BMI) changes and the adipose tissue levels of HCB and HCHs. No association was found between OCPs levels and dietary factors. However, our study suggests that fish consumption may be an important contributor of PCBs adipose tissue content of PCBs in Tunisian people. The presented work is highly significant, being the first study pointing out the chronic exposure to OCs in Bizerte. - Highlights: • First study to report HCB, HCHs, DDTs and PCBs in adipose tissues from Tunisia. • The measurement levels showed a general pattern as DDTs>PCBs> HCB>HCHs. • p,p′-DDE and PCB-180, PCB-153 and PCB-138 were the marker substances of OCPs and PCBs, respectively. • Strong associations between concentrations of OCPs and PCBs suggest Tunisian are exposed via similar routes. • Fish consumption is a major source of dietary exposure to PCBs.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Association between prenatal bisphenol A and phthalate exposures and fetal metabolic related biomarkers: The Hokkaido study on Environment and Children's Health

Highlights: • Early pregnancy exposure to bisphenol A, DBP and DEHP was observed. • Maternal bisphenol A level was negatively associated with cord leptin level. • Early pregnancy exposure to DEHP and DBP may decrease cord leptin levels. Bisphenol A and phthalates are widely detected in human urine, blood, breast milk, and amniotic fluid. Both bisphenol A and phthalates have been suggested as playing a role in obesity epidemics. Exposure to these chemicals during fetal development, and its consequences should be concerning because they can cross the placenta. Thus, this study aimed to assess the association between prenatal exposure to bisphenol A and phthalates, and cord blood metabolic-related biomarkers. Maternal serum was used during the first trimester, to determine prenatal exposure to bisphenol A and phthalates. Levels of metabolic-related biomarkers in the cord blood were also determined. Linear regression models were applied to the 365 participants with both, exposure and biomarker assessments, adjusted for maternal age, pre-pregnancy body mass index, parity, education, and sex of the child. The level of bisphenol A was negatively associated with the leptin level (β = −0.06, 95% confidence interval [CI]: −0.11, −0.01), but was positively associated with the high-molecular-weight adiponectin level, with marginal significance (β = 0.03, 95%CI: 0.00, 0.06). The mono-isobutyl phthalate (MiBP), mono-n-butyl phthalate (MnBP), mono-(2-ethylhexyl) phthalate (MEHP), and summation of MEHP and MECPP to represent DEHP exposure (∑DEHPm) levels were inversely associated with the leptin levels (β=−0.14, 95%CI: −0.27, −0.01; β = −0.12, 95%CI: −0.24, 0.00 with marginal significance; β=0.08, 95%CI: −0.14, −0.03; and β = −0.09, 95%CI: −0.16, −0.03, respectively). The present study provided some evidence that prenatal exposure to bisphenol A and certain phthalates may modify fetal adiponectin and leptin levels.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Persistent organic pollutants as predictors of increased FSH:LH ratio in naturally cycling, reproductive age women

Highlights: • Endocrine disrupting chemicals pose a threat to female fecundity and reproduction. • Examined organochlorines and a marker of ovarian responsivity, FSH:LH ratio. • Increasing concentrations of estrogenic PCBs predict FSH:LH ratio > 2. • PCB congeners related to airborne exposure are associated with FSH:LH ratio > 2. Although several recent studies suggest endocrine disrupting compounds, such as polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (p,p′, DDE), and hexachlorobenzene (HCB), target different organs and systems in the body, their impact on female reproductive function in humans is not well characterized. We seek to determine the relationship between several known endocrine disrupting compounds and a marker of ovarian responsivity, the FSH:LH ratio (higher ratio indicates less ovarian responsivity). For this analysis, 169 naturally cycling women between 21 and 38 years of age completed interviews and had their blood drawn on day 3 of their menstrual cycle for analyses of toxicants, gonadal sex hormones (E{sub 2} and P{sub 4}), and gonadotropins (FSH and LH). PCB congeners were classified into five groups based on their environmental persistence, distribution in human tissue, and toxicological action, reflecting the structure, mechanism, and known biological activity of individual PCB congeners. For every unit (ppb) increase in the level of the estrogenic PCB group, there was a 5-fold greater risk of a FSH:LH ratio ≥ 2, controlling for individual differences in age, percent body fat, cycle day 3 estradiol levels, parity, alcohol use and cigarette smoking in the past year (exp[ß] = 5; p = ≤0.01). PCB congeners identified as estrogenic were analyzed individually, and, of the 19 potentially estrogenic congeners, five were significantly, and positively related to an increased FSH:LH ratio. Four of these congeners are non-persistent, easily volatilize in the environment, and are easily metabolized, and hence, are indicative of very recent or current exposure. p,p′-DDE and HCB were not associated with FSH:LH ratio. We find a clinical indicator of ovarian responsivity, FSH:LH ratio, is associated with a specific group of estrogenic PCBs. These congeners may become airborne when they volatilize from dredged PCB-contaminated soil or from indoor PCB-containing window caulk and sealants in older buildings leading to inhalation exposure. PCB exposure, particularly to non-persistent, estrogenic congeners, may pose an unrecognized threat to female fecundity within the general population.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

Assessing the levelized cost of energy in South Korea

This study evaluates the levelized cost of energy (LCOE) for various energy technologies in the Republic of Korea (Korea) from 2023 to 2050, highlighting cost trajectories and potential crossovers among competing technologies. The analysis projects that, based on our set of assumptions, utility-scale photovoltaic systems achieve lower LCOEs than nuclear by 2030, while fixed offshore wind is expected to become cost-competitive with coal-fired generation around the same time. Floating offshore wind is projected to reach cost parity with coal in the late 2030s. Co-firing with natural gas and green hydrogen is identified as the highest-cost generation option due to high natural gas and green fuel costs and declining capacity utilization. This study further examines the potential for hybrid systems that integrate renewable energy with energy storage to serve as flexible, cost-effective, zero-emission alternatives to green hydrogen-based generation. Spatial LCOE assessments indicate that near-shore offshore wind sites may achieve lower costs despite modest capacity factors, contingent on site-specific factors such as grid integration and social acceptance. The findings indicate that renewable energy technologies are expected to experience continued cost declines, with solar photovoltaic becoming the most competitive energy source in Korea by 2030–2035. Incorporating social costs accelerates this shift from conventional alternatives.

Green hydrogen↗
DOE OSTI2024

Analyzing the upscaling potential and geospatial siting of calcination-free calcium hydroxide production in the United States

This study evaluates the techno-economic feasibility and the embodied carbon dioxide intensity (eCI) of a novel process for producing nominally pure (>95 mass %) calcium hydroxide without the need for the thermal calcination of limestone. The process relies on the aqueous extraction of calcium from alkaline industrial wastes following which portlandite (Ca(OH) 2 : CH, a.k.a. slaked lime or hydrated lime) is precipitated by application of a waste-heat based thermal swing. This approach takes advantage of the temperature dependent solubility of CH at ambient pressure. We evaluated the feasibility of implementing this process in the U.S. based on the geospatial availability of waste heat and slags as a Ca-source. For the base case, the cost of production of “Low-Temperature Portlandite (LTP)” is 2-to-3 times that of traditional portlandite (~$180/tonne). The main driver of cost is the electricity demand for reverse osmosis (RO) which is used to concentrate Ca-ions in solution, and the costs of membrane replacement. Our sensitivity analysis showed that parity with the cost of production of traditional portlandite is readily achievable by selecting membranes with better durability (i.e., better pH resistance) and flux (i.e., higher permeability) without sacrificing selectivity. Significantly, LTP features an eCI that is between 40%- and - 80 % lower than its traditional counterpart when electricity is sourced from natural gas combustion or wind power, respectively. Finally, our geospatial analysis reveals that there are three areas in the U.S. with the potential for implementation of industrial-scale facilities that could produce at least 50 tonnes of pure Ca(OH) 2 per day, while achieving a production cost of ~$270 per tonne of Ca(OH) 2 , owing to the proximity between slag feedstocks and waste heat sources.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2025

Fuel cells for single-aisle regional aircraft: System configuration, performance and cost

A hydrogen fuel cell propelled electric aircraft can compete with incumbent turbofan technologies for single-aisle regional aircraft by coupling design of stack, air handling, thermal management, propulsion, and airframe to optimize performance. The stack operates at 95°C to facilitate heat rejection during take-off and below 75°C during cruise to extend lifetime and is oversized to satisfy power requirements at end of life. A multi-stage turbocompressor with a compression ratio >10 is selected to reach high stack power density at 11,300-m cruise altitude. The propulsion system is configured to accommodate air handling within the core duct, an inclined heat exchanger in the outer duct to limit the nacelle size, and variable area nozzles to independently control mass flows through the core and bypass ducts. The airframe is modified for maximum lift coefficient and longer balanced field length for dramatically reduced thrust during take-off, and the fuselage is stretched by 20% to store liquid hydrogen (LH 2 ). Modularization of power systems promotes safety in one engine inoperative scenarios and allows reaching specific power metrics for stack, balance-of-plant and fuel cell system (FCS), necessary for acceptable take-off weight. In conclusion, cost parity requires increase in FCS lifetime, LH 2 cost reduction, and improved FCS specific power.

Catalyst durability↗
DOE OSTI2024

Techno-economic and life cycle analysis of synthetic natural gas production from low-carbon H 2 and point-source or atmospheric CO 2 in the United States

Synthetic natural gas (SNG) is of great interest in reducing fossil energy consumption while maintaining compatibility with existing NG infrastructure and end-use applications equipment. SNG can be produced using clean H 2 generated from renewable or nuclear energy and CO 2 captured from stationary sources or the atmosphere. In this study, we develop an engineering process model of SNG production using Aspen Plus® and production scales reported by the industry. We examine the levelized cost and life cycle greenhouse gas (GHG) emissions of SNG production under various CO 2 supply scenarios. Considering the higher cost of H 2 transportation compared with CO 2 transportation, we assume that CO 2 feedstock is transported via pipeline to the H 2 production location, which is collocated with the SNG plant. We also evaluate the cost of CO 2 captured from the atmosphere, assuming the direct air capture process can occur near the SNG facility. Depending on the CO 2 supply chain, the levelized cost of SNG is estimated to be in the range of $\$45–76$ per million British thermal units (MMBtu) on a higher heating value (HHV) basis. The SNG production cost may be reduced to $\$27–57$/MMBtu-HHV by applying a tax credit available in the United States for low-carbon H 2 production (45V). With a lower electricity price of 3¢/kWh for water electrolysis and accounting for a 45V tax credit, the SNG cost reaches parity with the cost of fossil NG. Depending on the CO 2 supply chain, SNG can reduce life cycle GHG emissions by 52–88% compared with fossil NG.

03 NATURAL GAS↗
DOE OSTI2016

Divalent europium doped CaF 2 and BaF 2 nanocrystals from ionic liquids

A new, facile and quick synthesis method for Eu 2+ doped the alkaline earth fluorides was developed using ionic liquids as solvent, precursor and capping agent. Reductive atmosphere and very high temperatures were avoided, while still attaining the desired structure, small particle sizes and divalent oxidation state of the lanthanide. Here, this opens the door for the development of new Ln 2+ doped nanomaterials. Here, the successful Eu 2+ incorporation was proven by optical spectroscopic measurements which showed the spin and parity allowed f-d transitions of Eu 2+ in CaF 2 :Eu 2+ /BaF 2 :Eu 2+ . 4f 7 -4f 7 transitions could be observed at low temperatures (7 K).

36 MATERIALS SCIENCE↗
DOE OSTI2025

What causes the variation in superconducting properties of UTe 2 ?

Reaching a consensus on the superconducting order parameter of unconventional superconductors remains a central challenge in the field of magnetically-mediated superconductivity. Though UTe 2 is largely accepted as a rare example of an odd-parity superconductor, its precise order parameter remains highly debated, even at ambient conditions. A key underlying issue is the large sample-to-sample variation in superconducting properties at zero applied pressure and magnetic field. Here, we investigate the origin of the observed variation by means of single crystal x-ray diffraction (SC-XRD) and scanning transmission electron microscopy (STEM) measurements. Our results reveal highly ordered crystalline lattices, in agreement with the expected Immm structure, and no signs of uranium vacancies. Tiny amounts of interstitial defects, however, are observed on the Te2 layers that host Te chains along the b axis. We argue that these defects give rise to slightly enhanced atomic displacement parameters observed in SC-XRD data and are enough to disrupt the unconventional superconducting state in UTe 2 . Our findings highlight the need to focus future order parameter determination efforts on single crystals of UTe 2 with minimal amounts of structural disorder.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2015

On the Stark effect in open shell complexes exhibiting partially quenched electronic angular momentum: Infrared laser Stark spectroscopy of OH–C 2 H 2 , OH–C 2 H 4 , and OH–H 2 O

The Stark effect is considered for polyatomic open shell complexes that exhibit partially quenched electronic angular momentum. Matrix elements of the Stark Hamiltonian represented in a parity conserving Hund's case (a) basis are derived for the most general case, in which the permanent dipole moment has projections on all three inertial axes of the system. Transition intensities are derived, again for the most general case, in which the laser polarization has projections onto axes parallel and perpendicular to the Stark electric field, and the transition dipole moment vector is projected onto all three inertial axes in the molecular frame. As a result, simulations derived from this model are compared to experimental rovibrational Stark spectra of OH-C 2 H 2 , OH-C 2 H 4 , and OH-H 2 O complexes formed in helium nanodroplets.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

Direct hydrogen fuel cell electric vehicle cost analysis: System and high-volume manufacturing description, validation, and outlook

Here, direct hydrogen fuel cell electric vehicles (FCEVs) produce only water as a byproduct, thereby eliminating tailpipe carbon and criteria air pollutant emissions associated with internal combustion engine vehicles (ICEVs). However, in order to achieve economic parity with ICEVs, technological challenges must be overcome to lower system cost. The U.S. Department of Energy (DOE) monitors estimated fuel cell (FC) system cost and tracks progress towards milestones by techno-economic analysis based on demonstrated laboratory technologies for a next-generation 80 kWnet automotive FC stack for light-duty vehicles. The findings of the 2017 automotive FC system cost analysis are summarized, including the baseline system characteristics and specifications and the results of Design for Manufacture and Assembly (DFMA ® ) analysis of system manufacturing across a range of annual production rates. The highest volume predictions, for 100,000 and 500,000 units per year, result in a total system cost of 50/kWnet and 45/kWnet, respectively. The assumptions and methodology of the DFMA® analysis of the 2017 baseline FC system were validated by comparison with the FC system in the commercially available Toyota Mirai. One prospective pathway for decreasing system cost to 30/kW net needed for cost competitiveness with ICEVs is outlined.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2015

Vacuum-free laminated top electrode with conductive tapes for scalable manufacturing of efficient perovskite solar cells

The efficiency of organometal trihalide perovskites (OTP) solar cells have reached that parity of single crystal silicon, and its nature abundant raw material and solution-process capability promise a bright future for commercialization. However, the vacuum based techniques for metal electrode deposition and additional encapsulation layer increase the cost of the perovskite solar cells dramatically and impede their commercialization process. Here, we report a vacuum-free low temperature lamination technique to fabricate the top electrode by commercial conductive tapes (C-tape). The simple fabrication method yields good quality contact and high efficiency device of 12.7%. The C-tapes also encapsulated the devices effectively, resulting in greatly improved device stability. As a result, the combination of lamination of electrodes and encapsulation layers into a single step significantly reduce the cost of device fabrication.

14 SOLAR ENERGY↗
DOE OSTI2014

Nuclear Data Sheets for A = 248

Detailed level schemes, decay schemes, and the experimental data on which they are based are presented for all nuclei with mass number A=248. The experimental reaction and decay data are evaluated; inconsistencies and discrepancies are noted; and adopted values are given for various level properties (including spin and parity, halflife, and configuration), γ properties (including energy, intensity, and multipole character) and α properties (including energy, intensity, and hindrance factor). This evaluation replaces the A=248 evaluation published by A. Akovali in Nuclear Data Sheets 87, 249 (1999)

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2015

Nuclear Data Sheets for A = 182

Nuclear spectroscopic information for known nuclides of mass number 182 (Yb,Lu,Hf,Ta,W,Re,Os,Ir,Pt,Au, Hg,Tl,Pb) with Z=70 to 82 and N=112 to 100 have been evaluated and presented together with adopted energies and Jπ of levels in these nuclei. No excited state data are yet available for {sup 182}Y and {sup 182}Lu, while only limited structure information is available for {sup 182}Pb and {sup 182}Tl. Rotational band structures are known for {sup 182}Hg and {sup 182}Au but spin–parity assignments remain largely tentative. The decays of {sup 182}Lu, {sup 182}Hg, {sup 182}Au and {sup 182}Tl are not well established. The {sup 182}Hf isotope is of geophysical and astrophysical interest. This evaluation supersedes previous full evaluations of A = 182 published by 2010Si13, 1988Fi05 and 1975Sc13, and a selected (mainly high–spin) update of A = 182 published by 1995Si04. Only the Adopted properties of levels and gamma rays are presented in NDS, consult the ENSDF database at (www.nndc.bnl.gov/ensdf/) for details of individual reaction and decay datasets.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2020

Nuclear Data Sheets for A=98

Experimental spectroscopic data on nuclear structure and decay are evaluated for known nuclides of mass 98 (Br, Kr, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In). Detailed evaluation results of individual reactions and decays are presented together with the Adopted values that are recommended for level properties, γ and β radiations, and other spectroscopic information. 98 Mo remains as the most extensively studied nuclide via various reactions and decays. Level schemes of Sr, Y, Zr, Tc, and Pd nuclides in this mass chain are also well established to date; while Kr, Rb, Nb, Ag and Cd are amongst the least-studied ones for excited states, with only limited data available for each. On the neutron-rich side, 98 Br has been identified in the 9 Be(238U,F) reaction, but no spectroscopic data are yet available, while for 98 In on the proton-rich side, only the ground state and an isomer are known with half-lives measured but their spin-parities and the absolute level energy of the isomer yet to be determined. While 98 Ru and 98 Rh have also been extensively studied, large discrepancies exist between the high-spin sections of the proposed level schemes in different measurements, and these need to be clarified and resolved with further experimental investigations to improve the currently-adopted ones, which have been selected from the measurements with higher statistics, considering no other criteria of preference. Furthermore, this work supersedes all the earlier evaluations of A=98 (2003Si07, 1998Si18, 1992Si21, 1983Mu21, 1974Me34).

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗