cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.7274/25607793
title: Advancing the Technology Readiness of the Nonlinear Curvature Wavefront Sensor through Modeling and Laboratory Investigation

description: Adaptive optics (AO) systems provide a means for astronomers to overcome the distorting effects of the Earth's tubulent atmosphere on incoming light from celestial objects. A vital component of any AO system is the wavefront sensor (WFS). The most commonly used WFS, the Shack-Hartmann wavefront sensor (SHWFS), is more than an order of magnitude less sensitive than a theoretically ideal sensor. Further exacerbating this problem, the effects of scintillation locally reduce the signal in the SHWFS through interference effects, causing a reduction in performance. These impediments limit the science that can be pursued using ground-based telescopes, particularly at visible wavelengths and high airmass. 
 
In this PhD dissertation, a systematic exploration of an alternative to the SHWFS, the nonlinear curvature wavefront sensor (nlCWFS), is performed. This work focuses on both theoretical and laboratory research that aims to mature the nlCWFS architecture as a candidate replacement for the SHWFS. First, a comprehensive, simulation-based sensitivity analysis is presented on the optimal values of both the number and location of nlCWFS measurement planes. Next, the effects of scintillation on the nlCWFS compared to the SHWFS are studied in a laboratory testbed with increasing values of turbulence strength. Finally, the laboratory testbed is used to assess and validate the performance of the nlCWFS in the presence of detector readout noise.

The results of both numerical simulations and laboratory experiments demonstrate that the nlCWFS consistently delivers improved sensitivity and robustness to scintillation compared to an equivalent SHWFS. Therefore, AO systems that employ a nlCWFS will be capable of accessing fainter natural guide star and lower-power laser guide star targets, while simultaneously enabling correction across a broad range of turbulence strengths and airmass. The results of this work help to inform the practicality of using a nlCWFS as a platform technology across multiple scientific and engineering disciplines.
DOI: 10.7274/25607793.v1
title: Advancing the Technology Readiness of the Nonlinear Curvature Wavefront Sensor through Modeling and Laboratory Investigation

description: Adaptive optics (AO) systems provide a means for astronomers to overcome the distorting effects of the Earth's tubulent atmosphere on incoming light from celestial objects. A vital component of any AO system is the wavefront sensor (WFS). The most commonly used WFS, the Shack-Hartmann wavefront sensor (SHWFS), is more than an order of magnitude less sensitive than a theoretically ideal sensor. Further exacerbating this problem, the effects of scintillation locally reduce the signal in the SHWFS through interference effects, causing a reduction in performance. These impediments limit the science that can be pursued using ground-based telescopes, particularly at visible wavelengths and high airmass. 
 
In this PhD dissertation, a systematic exploration of an alternative to the SHWFS, the nonlinear curvature wavefront sensor (nlCWFS), is performed. This work focuses on both theoretical and laboratory research that aims to mature the nlCWFS architecture as a candidate replacement for the SHWFS. First, a comprehensive, simulation-based sensitivity analysis is presented on the optimal values of both the number and location of nlCWFS measurement planes. Next, the effects of scintillation on the nlCWFS compared to the SHWFS are studied in a laboratory testbed with increasing values of turbulence strength. Finally, the laboratory testbed is used to assess and validate the performance of the nlCWFS in the presence of detector readout noise.

The results of both numerical simulations and laboratory experiments demonstrate that the nlCWFS consistently delivers improved sensitivity and robustness to scintillation compared to an equivalent SHWFS. Therefore, AO systems that employ a nlCWFS will be capable of accessing fainter natural guide star and lower-power laser guide star targets, while simultaneously enabling correction across a broad range of turbulence strengths and airmass. The results of this work help to inform the practicality of using a nlCWFS as a platform technology across multiple scientific and engineering disciplines.
DOI: 10.7274/25608543
title: Stellar Neutron Sources for the Slow Neutron Capture Nucleosynthesis

description: The interplay between the 22Ne(a,g)26Mg and the competing 22Ne(a,n)25Mg reactions determines the efficiency of the latter as a neutron source at the temperatures of stellar helium burning. In both cases, the rates are dominated by the alpha-cluster resonance at 830 keV. This resonance plays a particularly important role in determining the strength of the neutron flux for both the weak and main s-process as well as the n-process. Recent experimental studies based on transfer reactions suggest that the neutron and gamma-ray strengths for this resonance are approximately equal.
In this work, the 22Ne(a,n)25Mg resonance strength has been remeasured and found to be similar to the previous direct studies. This reinforces an 830 keV resonance strength that is approximately a factor of three larger for the 22Ne(a,n)25Mg reaction than for the 22Ne(a,g)26Mg reaction. 
The reaction rate of the 22Ne(a,g)26Mg is dominated by the low energy resonances at E_{alpha,lab} = 650 and 830 keV respectively. The E_{alpha,lab} = 830 keV resonance has been measured previously, but there are some uncertainties in the previous measurements. We confirmed the measurement of the E_{alpha,lab} = 830 keV resonance using implanted 22Ne targets. We obtained a resonance strength of 35 +/- 4 micro eV, and provide a weighted average of the present and previous measurements of 35 +/- 2 micro eV with reduced uncertainties compared to previous studies. We also attempted to measure the strength of the predicted resonance at E_{alpha,lab} = 650 keV directly for the first time and found an upper limit of 0.15 micro eV for the strength of this resonance.
The 25Mg nuclei produced from the 22Ne(a,n)25Mg reaction affect the overall neutron flux by the 25Mg(a,n)28Si reaction which serves as an additional neutron source for the weak s-process during the neon burning phase in massive stars. Past attempts to measure the 25Mg(a,n)28Si reaction using neutron counters have been greatly hindered by low Z background reactions. In the present work, neutron spectroscopy has been accomplished using deuterated liquid scintillator detectors combined with spectrum unfolding to make an improved measurement of the 25Mg(a,n)28Si reaction at low energies. Measurements of the cross section have been preformed down to E_alpha ~ 1.5 MeV with an unprecedented level of background rejection. In addition, the separation of the different background contributions gives further insight into the results of previous counter measurements.
DOI: 10.7274/25608543.v1
title: Stellar Neutron Sources for the Slow Neutron Capture Nucleosynthesis

description: The interplay between the 22Ne(a,g)26Mg and the competing 22Ne(a,n)25Mg reactions determines the efficiency of the latter as a neutron source at the temperatures of stellar helium burning. In both cases, the rates are dominated by the alpha-cluster resonance at 830 keV. This resonance plays a particularly important role in determining the strength of the neutron flux for both the weak and main s-process as well as the n-process. Recent experimental studies based on transfer reactions suggest that the neutron and gamma-ray strengths for this resonance are approximately equal.
In this work, the 22Ne(a,n)25Mg resonance strength has been remeasured and found to be similar to the previous direct studies. This reinforces an 830 keV resonance strength that is approximately a factor of three larger for the 22Ne(a,n)25Mg reaction than for the 22Ne(a,g)26Mg reaction. 
The reaction rate of the 22Ne(a,g)26Mg is dominated by the low energy resonances at E_{alpha,lab} = 650 and 830 keV respectively. The E_{alpha,lab} = 830 keV resonance has been measured previously, but there are some uncertainties in the previous measurements. We confirmed the measurement of the E_{alpha,lab} = 830 keV resonance using implanted 22Ne targets. We obtained a resonance strength of 35 +/- 4 micro eV, and provide a weighted average of the present and previous measurements of 35 +/- 2 micro eV with reduced uncertainties compared to previous studies. We also attempted to measure the strength of the predicted resonance at E_{alpha,lab} = 650 keV directly for the first time and found an upper limit of 0.15 micro eV for the strength of this resonance.
The 25Mg nuclei produced from the 22Ne(a,n)25Mg reaction affect the overall neutron flux by the 25Mg(a,n)28Si reaction which serves as an additional neutron source for the weak s-process during the neon burning phase in massive stars. Past attempts to measure the 25Mg(a,n)28Si reaction using neutron counters have been greatly hindered by low Z background reactions. In the present work, neutron spectroscopy has been accomplished using deuterated liquid scintillator detectors combined with spectrum unfolding to make an improved measurement of the 25Mg(a,n)28Si reaction at low energies. Measurements of the cross section have been preformed down to E_alpha ~ 1.5 MeV with an unprecedented level of background rejection. In addition, the separation of the different background contributions gives further insight into the results of previous counter measurements.
DOI: 10.15468/dl.9zerbg
title: Occurrence Download

description: A dataset containing 77 species occurrences available in GBIF matching the query:
{
 "TaxonKey" : [
 "is Chamaecrista caribaea (Northr.) Britton"
 ]
}

 The dataset includes 77 records from 15 constituent datasets; see https://api.gbif.org/v1/occurrence/download/0008204-241107131044228/datasets/export for details.
 
Data from some individual datasets included in this download may be licensed under less restrictive terms.
DOI: 10.15468/dl.wbmp3w
title: Occurrence Download

description: A dataset containing 80211 species occurrences available in GBIF matching the query:
{
 "and" : [
 "DatasetKey is iNaturalist Research-grade Observations",
 "Geometry POLYGON((-100.46087 25.54247,-100.15948 25.54247,-100.15948 25.75755,-100.46087 25.75755,-100.46087 25.54247))"
 ]
}

 The dataset includes 80211 records from 1 constituent datasets; see https://api.gbif.org/v1/occurrence/download/0008199-241107131044228/datasets/export for details.
 
Data from some individual datasets included in this download may be licensed under less restrictive terms.
DOI: 10.15468/dl.y629pd
title: Occurrence Download

description: A dataset containing 48469 species occurrences available in GBIF matching the query:
{
 "DatasetKey" : [
 "is Bell Museum birds"
 ]
}

 The dataset includes 48469 records from 1 constituent datasets; see https://api.gbif.org/v1/occurrence/download/0008203-241107131044228/datasets/export for details.
 
Data from some individual datasets included in this download may be licensed under less restrictive terms.
DOI: 10.15468/dl.ktzjzs
title: Occurrence Download

description: A dataset containing 0 species occurrences available in GBIF matching the query:
{
 "and" : [
 "TaxonKey is Apus apus (Linnaeus, 1758)",
 "Year is 54",
 "Country is Netherlands"
 ]
}

 The dataset includes 0 records from 0 constituent datasets; see https://api.gbif.org/v1/occurrence/download/0008205-241107131044228/datasets/export for details.
DOI: 10.15468/dl.8vrutx
title: Occurrence Download

description: A dataset containing 0 species occurrences available in GBIF matching the query:
{
 "and" : [
 "TaxonKey is Haematopus ostralegus Linnaeus, 1758",
 "Year is 54",
 "Country is Netherlands"
 ]
}

 The dataset includes 0 records from 0 constituent datasets; see https://api.gbif.org/v1/occurrence/download/0008206-241107131044228/datasets/export for details.
DOI: 10.15468/dl.r29hju
title: Occurrence Download

description: A dataset containing 54 species occurrences available in GBIF matching the query:
{
 "and" : [
 "TaxonKey is Cephalobyrrhus japonicus Champion, 1925",
 "HasCoordinate is true",
 "Country is Japan",
 "HasGeospatialIssue is false"
 ]
}

 The dataset includes 54 records from 3 constituent datasets; see https://api.gbif.org/v1/occurrence/download/0223076-220831081235567/datasets/export for details.
 
Data from some individual datasets included in this download may be licensed under less restrictive terms.
DOI: 10.15468/dl.82f7kv
title: Occurrence Download

description: A dataset containing 0 species occurrences available in GBIF matching the query:
{
 "and" : [
 "TaxonKey is Protaetia formosana (Moser, 1910)",
 "HasCoordinate is true",
 "Country is Japan",
 "HasGeospatialIssue is false"
 ]
}

 The dataset includes 0 records from 0 constituent datasets; see https://api.gbif.org/v1/occurrence/download/0223085-220831081235567/datasets/export for details.
DOI: 10.15468/dl.vs9neb
title: Occurrence Download

description: A dataset containing 175 species occurrences available in GBIF matching the query:
{
 "TaxonKey" : [
 "is Juncus prominens (Buchenau) Miyabe & Kudô"
 ]
}

 The dataset includes 175 records from 21 constituent datasets; see https://api.gbif.org/v1/occurrence/download/0259122-230224095556074/datasets/export for details.
 
Data from some individual datasets included in this download may be licensed under less restrictive terms.
DOI: 10.15468/dl.8pmg4m
title: Occurrence Download

description: A dataset containing 356 species occurrences available in GBIF matching the query:
{
 "and" : [
 "TaxonKey is Harpalus jureceki (Jedlicka, 1928)",
 "HasCoordinate is true",
 "Country is Japan",
 "HasGeospatialIssue is false"
 ]
}

 The dataset includes 356 records from 9 constituent datasets; see https://api.gbif.org/v1/occurrence/download/0211312-220831081235567/datasets/export for details.
 
Data from some individual datasets included in this download may be licensed under less restrictive terms.
DOI: 10.15468/dl.ynr7wr
title: Occurrence Download

description: A dataset containing 475 species occurrences available in GBIF matching the query:
{
 "and" : [
 "TaxonKey is Santiria tomentosa Blume",
 "OccurrenceStatus is Present"
 ]
}

 The dataset includes 475 records from 25 constituent datasets; see https://api.gbif.org/v1/occurrence/download/0259100-230224095556074/datasets/export for details.
 
Data from some individual datasets included in this download may be licensed under less restrictive terms.
DOI: 10.15468/dl.rr7w4n
title: Occurrence Download

description: A dataset containing 7089597 species occurrences available in GBIF matching the query:
{
 "and" : [
 "OccurrenceStatus is Present",
 "TaxonKey is one of (Galerida cristata (Linnaeus, 1758), Alauda arvensis Linnaeus, 1758, Melanocorypha calandra (Linnaeus, 1766), Phylloscopus collybita (Vieillot, 1817))"
 ]
}

 The dataset includes 7089597 records from 3798 constituent datasets; see https://api.gbif.org/v1/occurrence/download/0211325-220831081235567/datasets/export for details.
 
Data from some individual datasets included in this download may be licensed under less restrictive terms.
DOI: 10.15156/bio/sh0180458.10fu
title: SH0180458.10FU

description: UNITE provides a unified way for delimiting, identifying, communicating, and working with DNA-based Species Hypotheses (SH). All fungal ITS sequences in the international nucleotide sequence databases are clustered to approximately the species level by applying a set of dynamic distance values (<0.5 - 3.0%). All species hypotheses are given a unique, stable name in the form of a DOI, and their taxonomic and ecological annotations are verified through distributed, web-based third-party annotation efforts. SHs are connected to a taxon name and its classification as far as possible (phylum, class, order, etc.) by taking into account identifications for all sequences in the SH. An automatically or manually designated sequence is chosen to represent each such SH. These sequences are released (https://unite.ut.ee/repository.php) for use by the scientific community in, for example, local sequence similarity searches and next-generation sequencing analysis pipelines. The system and the data are updated automatically as the number of public fungal ITS sequences grows.
DOI: 10.15156/bio/sh0180459.10fu
title: SH0180459.10FU

description: UNITE provides a unified way for delimiting, identifying, communicating, and working with DNA-based Species Hypotheses (SH). All fungal ITS sequences in the international nucleotide sequence databases are clustered to approximately the species level by applying a set of dynamic distance values (<0.5 - 3.0%). All species hypotheses are given a unique, stable name in the form of a DOI, and their taxonomic and ecological annotations are verified through distributed, web-based third-party annotation efforts. SHs are connected to a taxon name and its classification as far as possible (phylum, class, order, etc.) by taking into account identifications for all sequences in the SH. An automatically or manually designated sequence is chosen to represent each such SH. These sequences are released (https://unite.ut.ee/repository.php) for use by the scientific community in, for example, local sequence similarity searches and next-generation sequencing analysis pipelines. The system and the data are updated automatically as the number of public fungal ITS sequences grows.
DOI: 10.15156/bio/sh0180460.10fu
title: SH0180460.10FU

description: UNITE provides a unified way for delimiting, identifying, communicating, and working with DNA-based Species Hypotheses (SH). All fungal ITS sequences in the international nucleotide sequence databases are clustered to approximately the species level by applying a set of dynamic distance values (<0.5 - 3.0%). All species hypotheses are given a unique, stable name in the form of a DOI, and their taxonomic and ecological annotations are verified through distributed, web-based third-party annotation efforts. SHs are connected to a taxon name and its classification as far as possible (phylum, class, order, etc.) by taking into account identifications for all sequences in the SH. An automatically or manually designated sequence is chosen to represent each such SH. These sequences are released (https://unite.ut.ee/repository.php) for use by the scientific community in, for example, local sequence similarity searches and next-generation sequencing analysis pipelines. The system and the data are updated automatically as the number of public fungal ITS sequences grows.
DOI: 10.15156/bio/sh0180461.10fu
title: SH0180461.10FU

description: UNITE provides a unified way for delimiting, identifying, communicating, and working with DNA-based Species Hypotheses (SH). All fungal ITS sequences in the international nucleotide sequence databases are clustered to approximately the species level by applying a set of dynamic distance values (<0.5 - 3.0%). All species hypotheses are given a unique, stable name in the form of a DOI, and their taxonomic and ecological annotations are verified through distributed, web-based third-party annotation efforts. SHs are connected to a taxon name and its classification as far as possible (phylum, class, order, etc.) by taking into account identifications for all sequences in the SH. An automatically or manually designated sequence is chosen to represent each such SH. These sequences are released (https://unite.ut.ee/repository.php) for use by the scientific community in, for example, local sequence similarity searches and next-generation sequencing analysis pipelines. The system and the data are updated automatically as the number of public fungal ITS sequences grows.
DOI: 10.15156/bio/sh0180462.10fu
title: SH0180462.10FU

description: UNITE provides a unified way for delimiting, identifying, communicating, and working with DNA-based Species Hypotheses (SH). All fungal ITS sequences in the international nucleotide sequence databases are clustered to approximately the species level by applying a set of dynamic distance values (<0.5 - 3.0%). All species hypotheses are given a unique, stable name in the form of a DOI, and their taxonomic and ecological annotations are verified through distributed, web-based third-party annotation efforts. SHs are connected to a taxon name and its classification as far as possible (phylum, class, order, etc.) by taking into account identifications for all sequences in the SH. An automatically or manually designated sequence is chosen to represent each such SH. These sequences are released (https://unite.ut.ee/repository.php) for use by the scientific community in, for example, local sequence similarity searches and next-generation sequencing analysis pipelines. The system and the data are updated automatically as the number of public fungal ITS sequences grows.
DOI: 10.15156/bio/sh0180463.10fu
title: SH0180463.10FU

description: UNITE provides a unified way for delimiting, identifying, communicating, and working with DNA-based Species Hypotheses (SH). All fungal ITS sequences in the international nucleotide sequence databases are clustered to approximately the species level by applying a set of dynamic distance values (<0.5 - 3.0%). All species hypotheses are given a unique, stable name in the form of a DOI, and their taxonomic and ecological annotations are verified through distributed, web-based third-party annotation efforts. SHs are connected to a taxon name and its classification as far as possible (phylum, class, order, etc.) by taking into account identifications for all sequences in the SH. An automatically or manually designated sequence is chosen to represent each such SH. These sequences are released (https://unite.ut.ee/repository.php) for use by the scientific community in, for example, local sequence similarity searches and next-generation sequencing analysis pipelines. The system and the data are updated automatically as the number of public fungal ITS sequences grows.
DOI: 10.15156/bio/sh0180464.10fu
title: SH0180464.10FU

description: UNITE provides a unified way for delimiting, identifying, communicating, and working with DNA-based Species Hypotheses (SH). All fungal ITS sequences in the international nucleotide sequence databases are clustered to approximately the species level by applying a set of dynamic distance values (<0.5 - 3.0%). All species hypotheses are given a unique, stable name in the form of a DOI, and their taxonomic and ecological annotations are verified through distributed, web-based third-party annotation efforts. SHs are connected to a taxon name and its classification as far as possible (phylum, class, order, etc.) by taking into account identifications for all sequences in the SH. An automatically or manually designated sequence is chosen to represent each such SH. These sequences are released (https://unite.ut.ee/repository.php) for use by the scientific community in, for example, local sequence similarity searches and next-generation sequencing analysis pipelines. The system and the data are updated automatically as the number of public fungal ITS sequences grows.