Centimeter, Millimeter, and Submillimeter Observations of Comet l03P/Hartley 2

The close approach (0.12 AU) of Comet 103P/Hartley 2 to the Earth only 8 days prior to perihelion provided a unique opportunity to probe the chemical composition of this object. Additionally, supporting data was acquired during the EPOXI (Extrasolar Planet Observation and Deep Impact Extended Investigation) flyby mission [1], which provided high resolution infrared spectra and images. Observations were conducted from four facilities, contributing to the large ground-based consortium organized in support of the EPOXI mission [2]. The Arizona Radio Observatory's 12m telescope, Kitt Peak, AZ, and Submillimeter telescope, Mt. Graham, AZ, as well as the James Clerk Maxwell Telescope, Mauna Kea, HI and the Greenbank 100m telescope, Greenbank, WV, were employed for this study covering 20 cm, 3 cm, and 0.8-3 mm. Data were obtained, collectively, from 12 October 2010 to 5 November 2010 [3]. HCN, CH3OH, H2CO, HNC, OH, and CS were detected, and upper limits on the abundance of H2S, SO2, c-C3H2, and deuterated isotopologues of HCN, H2CO, and H2O were measured. Upper limits on the D/H ratio derived from DCN gave D/H less than 0.01[3]. Detailed analysis of these data will help constrain the temperature, abundances, variance or periodicity of a given species, and can be compared to results from other comets, as well as support the data obtained from the EPOXI mission. The full analysis and comparison will be presented

Detection of Cyclopropenylidene on Titan with ALMA

We report the first detection on Titan of the small cyclic molecule cyclopropenylidene (c-C3H2) from high-sensitivity spectroscopic observations made with the Atacama Large Millimeter/submillimeter Array. Multiple lines of cyclopropenylidene were detected in two separate data sets: ~251 GHz in 2016 (Band 6) and ~352 GHz in 2017 (Band 7). Modeling of these emissions indicates abundances of 0.50 ± 0.14 ppb (2016) and 0.28 ± 0.08 (2017) for a 350 km step model, which may either signify a decrease in abundance, or a mean value of 0.33 ± 0.07 ppb. Inferred column abundances are (3–5) × 1012 cm−2 in 2016 and (1–2) × 1012 cm−2 in 2017, similar to photochemical model predictions. Previously the C3H${}_{3}^{+}$ ion has been measured in Titan's ionosphere by Cassini's Ion and Neutral Mass Spectrometer (INMS), but the neutral (unprotonated) species has not been detected until now, and aromatic versus aliphatic structure could not be determined by the INMS. Our work therefore represents the first unambiguous detection of cyclopropenylidene, the second known cyclic molecule in Titan's atmosphere along with benzene (C6H6) and the first time this molecule has been detected in a planetary atmosphere. We also searched for the N-heterocycle molecules pyridine and pyrimidine finding nondetections in both cases, and determining 2σ upper limits of 1.15 ppb (c-C5H5N) and 0.85 ppb (c-C4H4N2) for uniform abundances above 300 km. These new results on cyclic molecules provide fresh constraints on photochemical pathways in Titan's atmosphere, and will require new modeling and experimental work to fully understand the implications for complex molecule formation

Evaporation kinetics in swollen porous polymeric networks

Ponencia presentada en el Congreso Euromar 2014.Fil: Velasco, Manuel Isaac. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Física Enrique Gaviola; Argentina.Fil: Silletta, Emilia Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Física Enrique Gaviola; Argentina.Fil: Monti, Gustavo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Física Enrique Gaviola; Argentina.Fil: Acosta, Rodolfo Héctor. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Física Enrique Gaviola; Argentina.Fil: Velasco, Manuel Isaac. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Silletta, Emilia Victoria. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Monti, Gustavo Alberto. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Acosta, Rodolfo Héctor. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Gomez, Cesar Gerardo. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina.Fil: Strumia, Miriam Cristina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina.Fil: Gomez, Cesar Gerardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina.Fil: Gomez, Cesar Gerardo. Universidad Nacional de Córdoba. Instituto Multidisciplinario de Biología Vegetal; Argentina.Fil: Strumia, Miriam Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina.Fil: Strumia, Miriam Cristina. Universidad Nacional de Córdoba. Instituto Multidisciplinario de Biología Vegetal; Argentina.Polymer matrices with well defined structure and pore sizes are widely used in several areas of chemistry such as catalysis, enzyme immobilization, HPLC, adsorbents or controlled drug release. These polymers have pores in its structure both in the dry and swollen state. Although it is well known that the structures and properties greatly differ between these two states, only few methods provide information about the swollen one, even though most of the applications involve the matrices in this situation. Nuclear Magnetic Resonance (NMR) is a suitable tool for the study of the molecular dynamics of different liquids spatially confined in macro, meso and nanopores, through changes in the relaxation times. In transverse relaxation experiments, either diffusion inside the pore, or relaxation induced by mobility restriction of the liquid near the wall, are additional sources of relaxation, which are extremely useful in the determination of structural and functional properties.Fil: Velasco, Manuel Isaac. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Física Enrique Gaviola; Argentina.Fil: Silletta, Emilia Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Física Enrique Gaviola; Argentina.Fil: Monti, Gustavo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Física Enrique Gaviola; Argentina.Fil: Acosta, Rodolfo Héctor. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Física Enrique Gaviola; Argentina.Fil: Velasco, Manuel Isaac. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Silletta, Emilia Victoria. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Monti, Gustavo Alberto. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Acosta, Rodolfo Héctor. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Gomez, Cesar Gerardo. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina.Fil: Strumia, Miriam Cristina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina.Fil: Gomez, Cesar Gerardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina.Fil: Gomez, Cesar Gerardo. Universidad Nacional de Córdoba. Instituto Multidisciplinario de Biología Vegetal; Argentina.Fil: Strumia, Miriam Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina.Fil: Strumia, Miriam Cristina. Universidad Nacional de Córdoba. Instituto Multidisciplinario de Biología Vegetal; Argentina.Física de los Materiales Condensado

ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP). I. Detection of New Hot Corinos with the ACA

We report the detection of four new hot corino sources, G211.47-19.27S, G208.68-19.20N1, G210.49-19.79W, and G192.12-11.10, from a survey study of Planck Galactic Cold Clumps in the Orion Molecular Cloud Complex with the Atacama Compact Array. Three sources had been identified as low-mass Class 0 protostars in the Herschel Orion Protostar Survey. One source in the lambda Orionis region is first reported as a protostellar core. We have observed abundant complex organic molecules (COMs), primarily methanol but also other oxygen-bearing COMs (in G211.47-19.27S and G208.68-19.20N1) and the molecule of prebiotic interest NH2CHO (in G211.47-19.27S), signifying the presence of hot corinos. While our spatial resolution is not sufficient to resolve most of the molecular emission structure, the large line width and high rotational temperature of COMs suggest that they likely reside in the hotter and innermost region immediately surrounding the protostar. In G211.47-19.27S, the D/H ratio of methanol ([CH2DOH]/[CH3OH]) and the(12)C/C-13 ratio of methanol ([CH3OH]/[(CH3OH)-C-13]) are comparable to those of other hot corinos. Hydrocarbons and long-carbon-chain molecules such as c-C(3)H(2)and HCCCN are also detected in the four sources, likely tracing the outer and cooler molecular envelopes.Peer reviewe

Comprehensive in vitro and in vivo studies of novel melt-derived Nb-substituted 45S5 bioglass reveal its enhanced bioactive properties for bone healing

The present work presents and discusses the results of a comprehensive study on the bioactive properties of Nb-substituted silicate glass derived from 45S5 bioglass. In vitro and in vivo experiments were performed. We undertook three different types of in vitro analyses: (i) investigation of the kinetics of chemical reactivity and the bioactivity of Nb-substituted glass in simulated body fluid (SBF) by 31P MASNMR spectroscopy, (ii) determination of ionic leaching profiles in buffered solution by inductively coupled plasma optical emission spectrometry (ICP-OES), and (iii) assessment of the compatibility and osteogenic differentiation of human embryonic stem cells (hESCs) treated with dissolution products of different compositions of Nb-substituted glass. The results revealed that Nb-substituted glass is not toxic to hESCs. Moreover, adding up to 1.3 mol% of Nb2O5 to 45S5 bioglass significantly enhanced its osteogenic capacity. For the in vivo experiments, trial glass rods were implanted into circular defects in rat tibia in order to evaluate their biocompatibility and bioactivity. Results showed all Nb-containing glass was biocompatible and that the addition of 1.3 mol% of Nb2O5, replacing phosphorous, increases the osteostimulation of bioglass. Therefore, these results support the assertion that Nb-substituted glass is suitable for biomedical applications

ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP): How Do Dense Core Properties Affect the Multiplicity of Protostars?

During the transition phase from a prestellar to a protostellar cloud core, one or several protostars can form within a single gas core. The detailed physical processes of this transition, however, remain unclear. We present 1.3 mm dust continuum and molecular line observations with the Atacama Large Millimeter/submillimeter Array toward 43 protostellar cores in the Orion molecular cloud complex (λ Orionis, Orion B, and Orion A) with an angular resolution of ∼0.″35 (∼140 au). In total, we detect 13 binary/multiple systems. We derive an overall multiplicity frequency (MF) of 28% ± 4% and a companion star fraction (CSF) of 51% ± 6%, over a separation range of 300-8900 au. The median separation of companions is about 2100 au. The occurrence of stellar multiplicity may depend on the physical characteristics of the dense cores. Notably, those containing binary/multiple systems tend to show a higher gas density and Mach number than cores forming single stars. The integral-shaped filament of the Orion A giant molecular cloud (GMC), which has the highest gas density and hosts high-mass star formation in its central region (the Orion Nebula cluster), shows the highest MF and CSF among the Orion GMCs. In contrast, the λ Orionis GMC has a lower MF and CSF than the Orion B and Orion A GMCs, indicating that feedback from H ii regions may suppress the formation of multiple systems. We also find that the protostars comprising a binary/multiple system are usually at different evolutionary stages.T.L. acknowledges support from the National Natural Science Foundation of China (NSFC) through grants No. 12073061 and No. 12122307, the International Partnership Program of the Chinese Academy of Sciences (CAS) through grant No. 114231KYSB20200009, the Shanghai Pujiang Program (20PJ1415500), and science research grants from the China Manned Space Project with no. CMS-CSST-2021-B06. K.T. was supported by Japan Society for the Promotion of Science (JSPS) KAKENHI (grant No. 20H05645). D.J. and J.d.F. are supported by NRC Canada and by NSERC Discovery Grants. C.-F.L. acknowledge grants from the Ministry of Science and Technology of Taiwan (MoST 107-2119-M-001-040-MY3 and 110-2112-M-001-021-MY3) and Academia Sinica (Investigator Award AS-IA-108-M01). This research was carried out in part at the Jet Propulsion Laboratory, which is operated by the California Institute of Technology under a contract with the National Aeronautics and Space Administration (80NM0018D0004). J.-E.L. was supported by a National Research Foundation of Korea grant funded by the Korean government (MSIT) (grant No. 2021R1A2C1011718). J.H. acknowledges the support of NSFC projects 11873086 and U1631237. This work is sponsored (in part) by the CAS, through a grant to the CAS South America Center for Astronomy in Santiago, Chile. S.-L.Q. is supported by the NSFC with grant No. 12033005. S.Z. acknowledges the support of the China Postdoctoral Science Foundation through grant No. 2021M700248. L.B. gratefully acknowledges support by the ANID BASAL projects ACE210002 and FB210003. P.S. was supported by a Grant-in-Aid for Scientific Research (KAKENHI No. 18H01259) of JSPS. V.-M.P. acknowledges support by the grant PID2020-115892GB-I00 funded by MCIN/AEI/10.13039/501100011033

The TOP-SCOPE Survey of Planck Galactic Cold Clumps : Survey Overview and Results of an Exemplar Source, PGCC G26.53+0.17

The low dust temperatures (<14 K) of Planck Galactic cold clumps (PGCCs) make them ideal targets to probe the initial conditions and very early phase of star formation. "TOP-SCOPE" is a joint survey program targeting similar to 2000 PGCCs in J = 1-0 transitions of CO isotopologues and similar to 1000 PGCCs in 850 mu m continuum emission. The objective of the "TOP-SCOPE" survey and the joint surveys (SMT 10 m, KVN 21 m, and NRO 45 m) is to statistically study the initial conditions occurring during star formation and the evolution of molecular clouds, across a wide range of environments. The observations, data analysis, and example science cases for these surveys are introduced with an exemplar source, PGCC G26.53+0.17 (G26), which is a filamentary infrared dark cloud (IRDC). The total mass, length, and mean line mass (M/L) of the G26 filament are similar to 6200 M-circle dot, similar to 12 pc, and similar to 500 M-circle dot pc(-1), respectively. Ten massive clumps, including eight starless ones, are found along the filament. The most massive clump as a whole may still be in global collapse, while its denser part seems to be undergoing expansion owing to outflow feedback. The fragmentation in the G26 filament from cloud scale to clump scale is in agreement with gravitational fragmentation of an isothermal, nonmagnetized, and turbulent supported cylinder. A bimodal behavior in dust emissivity spectral index (beta) distribution is found in G26, suggesting grain growth along the filament. The G26 filament may be formed owing to large-scale compression flows evidenced by the temperature and velocity gradients across its natal cloud.Peer reviewe

Conductivity/activation energy relationships for cement-based materials undergoing cyclic thermal excursions

The electrical conductivity of a range of concrete mixes, with and without supplementary cementitious materials (SCM), is studied through multiple cycles of heating and cooling over the extended temperature range -30/?70 C. When presented in an Arrhenius format, the experimental results display hysteresis effects at the lowtemperature end of the thermal cycle and, in those concretes containing supplementary cementitious materials at higher water/binder ratios, hysteresis effects were evident over the entire temperature range becoming more discernible with increasing number of thermal cycles. The depression in both the freezing and thawing point could be clearly identified and was used to estimate pore-neck and pore-cavity radii. A simplified approach is presented to evaluate the volumetric ratio of frozen pore water in terms of conductivity measurements. The results also show that the conductivity and activation energy of the concrete specimens were related to the water/binder ratio, type of SCM, physical state of the pore water and the thermal cycling regime