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This dataset contains all source data used to generate figures and all other findings of the publication: "Prediction of laser-induced breakdown in sub-micron-thick dielectric targets for laser-ion acceleration".

The in vivo evolution of radiotherapy necessitates innovative platforms for preclinical investigation, bridging the gap between bench research and clinical applications. Understanding the nuances of radiation response, specifically tailored to proton and photon therapies, is critical for optimizing treatment outcomes. Within this context, preclinical in vivo experimental setups incorporating image guidance for both photon and proton therapies are pivotal, enabling the translation of findings from small animal models to clinical settings. The SAPPHIRE project represents a milestone in this pursuit, presenting the installation of the small animal radiation therapy integrated beamline (SmART+ IB, Precision X-Ray Inc., Madison, Connecticut, USA) designed for preclinical image-guided proton and photon therapy experiments at University Proton Therapy Dresden. Through Monte Carlo simulations, low-dose on-site cone beam computed tomography imaging and quality assurance alignment protocols, the project ensures the safe and precise application of radiation, crucial for replicating clinical scenarios in small animal models. The creation of Hounsfield lookup tables and comprehensive proton and photon beam characterizations within this system enable accurate dose calculations, allowing for targeted and controlled comparison experiments. By integrating these capabilities, SAPPHIRE bridges preclinical investigations and potential clinical applications, offering a platform for translational radiobiology research and cancer therapy advancements.

Laser-plasma accelerators (LPAs) can deliver pico- to nanosecond long proton bunches, with ≥∼100 nC of charge dispersed over a broad energy spectrum. Increasing the repetition rates of today’s LPAs is a necessity for their practical application. This, however, creates a need for real-time proton bunch diagnostics. Scintillating screens are one detector solution, commonly applied in the field of electron LPAs for spatially resolved particle and radiation detection, yet their establishment for LPA proton detection is only slowly taking off. This is also due to the lack of available calibrations. In this paper, we present an absolute proton number calibration for the scintillating screen type DRZ High (Mitsubishi Chemical Corporation, Düsseldorf, Germany), one of the most sensitive screens according to calibrations for relativistic electrons and x-rays. For proton irradiation of the DRZ High screen, we find an increase in light yield of >60% compared to reference calibration data for relativistic electrons. The presented absolute light yield calibration shows an uncertainty of the proton number of 10% and can seamlessly be applied at other LPA facilities. Moreover, we investigate the scintillating screen light yield dependence on proton energy, since many types of scintillators (e.g., plastic, liquid, inorganic) show a reduced light yield for increased local energy deposition densities, an effect termed ionization quenching. The ionization quenching can reduce the light yield for low-energy protons by up to ∼20%. This work provides all necessary data for absolute spectral measurements of LPA protons with DRZ High scintillating screens, e.g., when these are used as detectors in the commonly available Thomson parabola spectrometers.

All necessary Data to recreate the published plots and images in the publication: "Absolute energy-dependent scintillating screen calibration for real-time detection of laser-accelerated proton bunches". Included are the raw scintillating screen images, the plotting data and Python Scripts used for calculations and plotting.

This repository contains the data shown in the results part of the paper entitled: SAPPHIRE - Establishment of small animal proton and photon image-guided radiation experiments.

The data set comprises raw data, processed data and detector data for the miniSCIDOM detector applied for characterization of proton bunches at a proton cyclotron and a laser-driven proton accelerator.

In dieser Arbeit wurden Antikörper mit Spezifität für Pro/Ala-reiche Sequenzen (PAS) funktionell und strukturell analysiert. Kristallstrukturen der rekombinanten Antikörperfragmente im Komplex mit den Epitoppeptiden lieferten Einblicke in die biomolekulare Erkennung der strukturell ungeordneten PAS-Polypeptidketten. Diese Antikörper bieten nicht nur wertvolle Reagenzien für die Analytik PASylierter Proteine; unter Nutzung eines Antikörperfragments mit moderater Affinität wurde zudem eine neuartige Strategie zu deren effizienter und schonender Affinitätsreinigung entwickelt., In this work, antibodies with specificity for Pro/Ala-rich sequences (PAS) were functionally and structurally analyzed. Crystal structures of the recombinant antibody fragments in complex with their epitope peptides provided insights into the biomolecular recognition of the structurally disordered PAS polypeptide chains. These antibodies not only provide valuable reagents for the analytics of PASylated proteins; using an antibody fragment with moderate affinity, a novel strategy for their efficient and gentle affinity purification was also developed.

Motivation: The precise targeting of antibodies and other protein therapeutics is required for their proper function and the elimination of deleterious off-target effects. Often the molecular structure of a therapeutic target is unknown and randomized methods are used to design antibodies without a model that relates antibody sequence to desired properties. Results: Here, we present Ens-Grad, a machine learning method that can design complementarity determining regions of human Immunoglobulin G antibodies with target affinities that are superior to candidates derived from phage display panning experiments. We also demonstrate that machine learning can improve target specificity by the modular composition of models from different experimental campaigns, enabling a new integrative approach to improving target specificity. Our results suggest a new path for the discovery of therapeutic molecules by demonstrating that predictive and differentiable models of antibody binding can be learned from high-throughput experimental data without the need for target structural data., National Institutes of Health (Grant R01CA218094)

BackgroundRare genetic variants cause pulmonary arterial hypertension, but the contribution of common genetic variation to disease risk and natural history is poorly characterised. We tested for genome-wide association for pulmonary arterial hypertension in large international cohorts and assessed the contribution of associated regions to outcomes.MethodsWe did two separate genome-wide association studies (GWAS) and a meta-analysis of pulmonary arterial hypertension. These GWAS used data from four international case-control studies across 11 744 individuals with European ancestry (including 2085 patients). One GWAS used genotypes from 5895 whole-genome sequences and the other GWAS used genotyping array data from an additional 5849 individuals. Cross-validation of loci reaching genome-wide significance was sought by meta-analysis. Conditional analysis corrected for the most significant variants at each locus was used to resolve signals for multiple associations. We functionally annotated associated variants and tested associations with duration of survival. All-cause mortality was the primary endpoint in survival analyses.FindingsA locus near SOX17 (rs10103692, odds ratio 1·80 [95% CI 1·55-2·08], p=5·13 × 10-15) and a second locus in HLA-DPA1 and HLA-DPB1 (collectively referred to as HLA-DPA1/DPB1 here; rs2856830, 1·56 [1·42-1·71], p=7·65 × 10-20) within the class II MHC region were associated with pulmonary arterial hypertension. The SOX17 locus had two independent signals associated with pulmonary arterial hypertension (rs13266183, 1·36 [1·25-1·48], p=1·69 × 10-12; and rs10103692). Functional and epigenomic data indicate that the risk variants near SOX17 alter gene regulation via an enhancer active in endothelial cells. Pulmonary arterial hypertension risk variants determined haplotype-specific enhancer activity, and CRISPR-mediated inhibition of the enhancer reduced SOX17 expression. The HLA-DPA1/DPB1 rs2856830 genotype was strongly associated with survival. Media

BackgroundRare genetic variants cause pulmonary arterial hypertension, but the contribution of common genetic variation to disease risk and natural history is poorly characterised. We tested for genome-wide association for pulmonary arterial hypertension in large international cohorts and assessed the contribution of associated regions to outcomes.MethodsWe did two separate genome-wide association studies (GWAS) and a meta-analysis of pulmonary arterial hypertension. These GWAS used data from four international case-control studies across 11 744 individuals with European ancestry (including 2085 patients). One GWAS used genotypes from 5895 whole-genome sequences and the other GWAS used genotyping array data from an additional 5849 individuals. Cross-validation of loci reaching genome-wide significance was sought by meta-analysis. Conditional analysis corrected for the most significant variants at each locus was used to resolve signals for multiple associations. We functionally annotated associated variants and tested associations with duration of survival. All-cause mortality was the primary endpoint in survival analyses.FindingsA locus near SOX17 (rs10103692, odds ratio 1·80 [95% CI 1·55-2·08], p=5·13 × 10-15) and a second locus in HLA-DPA1 and HLA-DPB1 (collectively referred to as HLA-DPA1/DPB1 here; rs2856830, 1·56 [1·42-1·71], p=7·65 × 10-20) within the class II MHC region were associated with pulmonary arterial hypertension. The SOX17 locus had two independent signals associated with pulmonary arterial hypertension (rs13266183, 1·36 [1·25-1·48], p=1·69 × 10-12; and rs10103692). Functional and epigenomic data indicate that the risk variants near SOX17 alter gene regulation via an enhancer active in endothelial cells. Pulmonary arterial hypertension risk variants determined haplotype-specific enhancer activity, and CRISPR-mediated inhibition of the enhancer reduced SOX17 expression. The HLA-DPA1/DPB1 rs2856830 genotype was strongly associated with survival. Media

Violent Inscriptions:Border Crossings in Early Nineteenth-Century American Literary HistoryLisa SchilzMy dissertation, Violent Inscriptions: Trauma, Translation, and Trans-nation in the Borderlands, stages convergences among a multilingual, multicultural web of texts and textual traces—Comanche, Ojibwe, Mexican, U.S., German—that thematize and register violence in the early national period. While 1848 has rightly been proclaimed as a (or even the) significant periodizing marker for American Studies, I return to the seminal complicated prior history of relations in the borderland spaces, a time when U.S. and Anglophone hegemony was not yet assured. The multimodal texts and cultural productions I recover (poetry, written and oral stories, government records) remain underexamined in U.S. literary studies and historiography, as they do not lend themselves easily to dominant grids of intelligibility, such as the nation-state, traditional periodizations, or monocultural and monolingual traditions. My comparative work retains field-specific research methods (such as from Indigenous and Latin American Studies) and brings them together in order to question the dominant lingering grids that do not capture the potential of these texts to envision alternative possibilities. The convergence of these materials troubles dominant Anglo-American definitions of land and property, temporality, and belonging as well as reframes the spatial and temporal markers of the borderlands. I extend the reach of the Latino-American borderlands model to feature Native American intellectual traditions more prominently. My project calls attention to the long-standing and diverse tribal sovereignties, pre-existing and surpassing what are now the boundaries of the U.S. nation state. It also unearths an unexpected connection to German immigrants, who abounded in and wrote prolifically about borderland spaces. Considering German immigrants allows for negotiations of racial boundaries within whit

Violent Inscriptions:Border Crossings in Early Nineteenth-Century American Literary HistoryLisa SchilzMy dissertation, Violent Inscriptions: Trauma, Translation, and Trans-nation in the Borderlands, stages convergences among a multilingual, multicultural web of texts and textual traces—Comanche, Ojibwe, Mexican, U.S., German—that thematize and register violence in the early national period. While 1848 has rightly been proclaimed as a (or even the) significant periodizing marker for American Studies, I return to the seminal complicated prior history of relations in the borderland spaces, a time when U.S. and Anglophone hegemony was not yet assured. The multimodal texts and cultural productions I recover (poetry, written and oral stories, government records) remain underexamined in U.S. literary studies and historiography, as they do not lend themselves easily to dominant grids of intelligibility, such as the nation-state, traditional periodizations, or monocultural and monolingual traditions. My comparative work retains field-specific research methods (such as from Indigenous and Latin American Studies) and brings them together in order to question the dominant lingering grids that do not capture the potential of these texts to envision alternative possibilities. The convergence of these materials troubles dominant Anglo-American definitions of land and property, temporality, and belonging as well as reframes the spatial and temporal markers of the borderlands. I extend the reach of the Latino-American borderlands model to feature Native American intellectual traditions more prominently. My project calls attention to the long-standing and diverse tribal sovereignties, pre-existing and surpassing what are now the boundaries of the U.S. nation state. It also unearths an unexpected connection to German immigrants, who abounded in and wrote prolifically about borderland spaces. Considering German immigrants allows for negotiations of racial boundaries within whit

Die vorliegende Dissertation behandelt die Bestimmung von Struktur-Aktivitäts-Beziehungen in Sonogashira-Kreuzkupplungsreaktionen. Mit dem parallelen „Multisubstrat-Screening“ wurde eine Hochdurchsatzmethode eingesetzt, mit dessen Hilfe annähernd 290 Sonogashira-Reaktionen mit stereoelektronisch systematisch variierten Substituenten in Bromaromaten, Alkinen und Phosphin-Liganden untersucht wurden. Bei diesem Verfahren wird eine ganze Serie verschiedener Reaktionen in einem einzigen Reaktionsgefäß unter den exakt identischen Reaktionsbedingungen durchgeführt und der zeitabhängige Konzentrationsverlauf aller Reaktanden mittels quantitativer Gaschromatographie analysiert. Erstmalig wird ein umfassendes Regelwerk aufgestellt, in dem der sterische und elektronische Einfluss der Reaktanden und der Steuerliganden für Sonogashira-Reaktionen beschrieben wird. Der von Substituenten ausgeübte elektronische Effekt an Bromaromaten erweist sich als weitaus bedeutsamer für den Ausgang von Sonogashira-Reaktionen als eine moderate sterische Belastung. In Alkinen führen Substituenten mit Elektronenakzeptorcharakter zu einer Zunahme der Produktbildungsgeschwindigkeit. Ein zunehmender sterischer Anspruch am Arylacetylen kann durch eine geringere Raumerfüllung des Steuerliganden ausgeglichen werden. Hohe Reaktivitäten werden in Sonogashira-Reaktionen hauptsächlich durch eine ideale sterische Kombination aus Phosphin und Alkin erreicht. Mit Hilfe der gewonnenen Erkenntnisse wurden optimierte Reaktionsprotokolle entwickelt, die die Synthesen zahlreicher substituierter 1,3-Diarylacetylene in guten bis hervorragenden Ausbeuten ermöglichen.

Die vorliegende Dissertation behandelt die Bestimmung von Struktur-Aktivitäts-Beziehungen in Sonogashira-Kreuzkupplungsreaktionen. Mit dem parallelen „Multisubstrat-Screening“ wurde eine Hochdurchsatzmethode eingesetzt, mit dessen Hilfe annähernd 290 Sonogashira-Reaktionen mit stereoelektronisch systematisch variierten Substituenten in Bromaromaten, Alkinen und Phosphin-Liganden untersucht wurden. Bei diesem Verfahren wird eine ganze Serie verschiedener Reaktionen in einem einzigen Reaktionsgefäß unter den exakt identischen Reaktionsbedingungen durchgeführt und der zeitabhängige Konzentrationsverlauf aller Reaktanden mittels quantitativer Gaschromatographie analysiert. Erstmalig wird ein umfassendes Regelwerk aufgestellt, in dem der sterische und elektronische Einfluss der Reaktanden und der Steuerliganden für Sonogashira-Reaktionen beschrieben wird. Der von Substituenten ausgeübte elektronische Effekt an Bromaromaten erweist sich als weitaus bedeutsamer für den Ausgang von Sonogashira-Reaktionen als eine moderate sterische Belastung. In Alkinen führen Substituenten mit Elektronenakzeptorcharakter zu einer Zunahme der Produktbildungsgeschwindigkeit. Ein zunehmender sterischer Anspruch am Arylacetylen kann durch eine geringere Raumerfüllung des Steuerliganden ausgeglichen werden. Hohe Reaktivitäten werden in Sonogashira-Reaktionen hauptsächlich durch eine ideale sterische Kombination aus Phosphin und Alkin erreicht. Mit Hilfe der gewonnenen Erkenntnisse wurden optimierte Reaktionsprotokolle entwickelt, die die Synthesen zahlreicher substituierter 1,3-Diarylacetylene in guten bis hervorragenden Ausbeuten ermöglichen.

Die vorliegende Dissertation behandelt die Bestimmung von Struktur-Aktivitäts-Beziehungen in Sonogashira-Kreuzkupplungsreaktionen. Mit dem parallelen „Multisubstrat-Screening“ wurde eine Hochdurchsatzmethode eingesetzt, mit dessen Hilfe annähernd 290 Sonogashira-Reaktionen mit stereoelektronisch systematisch variierten Substituenten in Bromaromaten, Alkinen und Phosphin-Liganden untersucht wurden. Bei diesem Verfahren wird eine ganze Serie verschiedener Reaktionen in einem einzigen Reaktionsgefäß unter den exakt identischen Reaktionsbedingungen durchgeführt und der zeitabhängige Konzentrationsverlauf aller Reaktanden mittels quantitativer Gaschromatographie analysiert. Erstmalig wird ein umfassendes Regelwerk aufgestellt, in dem der sterische und elektronische Einfluss der Reaktanden und der Steuerliganden für Sonogashira-Reaktionen beschrieben wird. Der von Substituenten ausgeübte elektronische Effekt an Bromaromaten erweist sich als weitaus bedeutsamer für den Ausgang von Sonogashira-Reaktionen als eine moderate sterische Belastung. In Alkinen führen Substituenten mit Elektronenakzeptorcharakter zu einer Zunahme der Produktbildungsgeschwindigkeit. Ein zunehmender sterischer Anspruch am Arylacetylen kann durch eine geringere Raumerfüllung des Steuerliganden ausgeglichen werden. Hohe Reaktivitäten werden in Sonogashira-Reaktionen hauptsächlich durch eine ideale sterische Kombination aus Phosphin und Alkin erreicht. Mit Hilfe der gewonnenen Erkenntnisse wurden optimierte Reaktionsprotokolle entwickelt, die die Synthesen zahlreicher substituierter 1,3-Diarylacetylene in guten bis hervorragenden Ausbeuten ermöglichen.

Die vorliegende Dissertation behandelt die Bestimmung von Struktur-Aktivitäts-Beziehungen in Sonogashira-Kreuzkupplungsreaktionen. Mit dem parallelen „Multisubstrat-Screening“ wurde eine Hochdurchsatzmethode eingesetzt, mit dessen Hilfe annähernd 290 Sonogashira-Reaktionen mit stereoelektronisch systematisch variierten Substituenten in Bromaromaten, Alkinen und Phosphin-Liganden untersucht wurden. Bei diesem Verfahren wird eine ganze Serie verschiedener Reaktionen in einem einzigen Reaktionsgefäß unter den exakt identischen Reaktionsbedingungen durchgeführt und der zeitabhängige Konzentrationsverlauf aller Reaktanden mittels quantitativer Gaschromatographie analysiert. Erstmalig wird ein umfassendes Regelwerk aufgestellt, in dem der sterische und elektronische Einfluss der Reaktanden und der Steuerliganden für Sonogashira-Reaktionen beschrieben wird. Der von Substituenten ausgeübte elektronische Effekt an Bromaromaten erweist sich als weitaus bedeutsamer für den Ausgang von Sonogashira-Reaktionen als eine moderate sterische Belastung. In Alkinen führen Substituenten mit Elektronenakzeptorcharakter zu einer Zunahme der Produktbildungsgeschwindigkeit. Ein zunehmender sterischer Anspruch am Arylacetylen kann durch eine geringere Raumerfüllung des Steuerliganden ausgeglichen werden. Hohe Reaktivitäten werden in Sonogashira-Reaktionen hauptsächlich durch eine ideale sterische Kombination aus Phosphin und Alkin erreicht. Mit Hilfe der gewonnenen Erkenntnisse wurden optimierte Reaktionsprotokolle entwickelt, die die Synthesen zahlreicher substituierter 1,3-Diarylacetylene in guten bis hervorragenden Ausbeuten ermöglichen.

Die vorliegende Dissertation behandelt die Bestimmung von Struktur-Aktivitäts-Beziehungen in Sonogashira-Kreuzkupplungsreaktionen. Mit dem parallelen „Multisubstrat-Screening“ wurde eine Hochdurchsatzmethode eingesetzt, mit dessen Hilfe annähernd 290 Sonogashira-Reaktionen mit stereoelektronisch systematisch variierten Substituenten in Bromaromaten, Alkinen und Phosphin-Liganden untersucht wurden. Bei diesem Verfahren wird eine ganze Serie verschiedener Reaktionen in einem einzigen Reaktionsgefäß unter den exakt identischen Reaktionsbedingungen durchgeführt und der zeitabhängige Konzentrationsverlauf aller Reaktanden mittels quantitativer Gaschromatographie analysiert. Erstmalig wird ein umfassendes Regelwerk aufgestellt, in dem der sterische und elektronische Einfluss der Reaktanden und der Steuerliganden für Sonogashira-Reaktionen beschrieben wird. Der von Substituenten ausgeübte elektronische Effekt an Bromaromaten erweist sich als weitaus bedeutsamer für den Ausgang von Sonogashira-Reaktionen als eine moderate sterische Belastung. In Alkinen führen Substituenten mit Elektronenakzeptorcharakter zu einer Zunahme der Produktbildungsgeschwindigkeit. Ein zunehmender sterischer Anspruch am Arylacetylen kann durch eine geringere Raumerfüllung des Steuerliganden ausgeglichen werden. Hohe Reaktivitäten werden in Sonogashira-Reaktionen hauptsächlich durch eine ideale sterische Kombination aus Phosphin und Alkin erreicht. Mit Hilfe der gewonnenen Erkenntnisse wurden optimierte Reaktionsprotokolle entwickelt, die die Synthesen zahlreicher substituierter 1,3-Diarylacetylene in guten bis hervorragenden Ausbeuten ermöglichen.

Following the inclusion of ecosystem services in the new global and national post 2010 biodiversity policies, this report addresses the need to upgrade the knowledge basis of ecosystem services and their social and economic values in order to inform ongoing policy design and decision making processes. In particular, this study addressed the present research capacity to map, assess and report ecosystem services as well as their implications for different community and regional policies.

Following the inclusion of ecosystem services in the new global and national post 2010 biodiversity policies, this report addresses the need to upgrade the knowledge basis of ecosystem services and their social and economic values in order to inform ongoing policy design and decision making processes. In particular, this study addressed the present research capacity to map, assess and report ecosystem services as well as their implications for different community and regional policies.

The two new high rise buildings for the European court in Luxembourg have been tested by a harmonic shaker and by Operational Modal Analysis. The background for the tests is to estimate the influence on the damping of one of the towers from a series of Tuned Liquid Dampers (TLDs) placed on top of the building. The TLDs have been designed to minimise the response of the buildings to wind loading, resulting in an increase in occupancy comfort. The harmonic excitation is performed to estimate the damping at a displacement level corresponding to significant wind loading whereas the OMA has been performed under minimum wind loading. The paper presents the testing programme and the main results of which one is a clear non-linear behaviour of the introduced viscous damping system.

The reciting of oral traditions, or storytelling, is the oldest form of human literary achievement. But because time changes everything, including oral traditions, human societies finally are forced to put their stories into written form to preserve them for posterity.

This study was conducted to determine the eligibility of several Nike sites within the boundaries of the Angeles National Forest in relation to the National Register of Historic Places. The sites investigated were Mt.Gleason (LA-04-L), Barley Flats (LA-09-L), Los Pinetos (LA-94-C&L), and Magic Mountain/Lang (LA-98-C&L). Information gathered as part of this study has made it possible to make a positive recommendation of National Register of Historic Places eligibility for the Mt. Gleason and Los Pinetos installations. These sites (which are less then 50 years old) were constructed during the period 1954-1956, and exhibits features of exceptional importance which are unique among recorded sites in the Los Angeles area. Finally, it was determined that the Nike installations located at Barley Flats and at Magic Mountain/Lang were not eligible to the National Register of Historic Places.

Laboratory testing of vane axial main mine fans has been completed in order to establish forward and reverse performance characteristics under controlled conditions; preliminary tests under field conditions have also been conducted. The data obtained suggest that reverse performance characteristics are dependant upon the blade angle and the hub to tip ratio. There is also evidence that reverse performance can be predicted for a family of blade angles in a given hub to tip ratio. In general, the air quantity delivered by the fan is 30% to 60% less in reverse than when operating in the normal forward mode., Laboratory testing of vane axial main mine fans has been completed in order to establish forward and reverse performance characteristics under controlled conditions; preliminary tests under field conditions have also been conducted. The data obtained suggest that reverse performance characteristics are dependant upon the blade angle and the hub to tip ratio. There is also evidence that reverse performance can be predicted for a family of blade angles in a given hub to tip ratio. In general, the air quantity delivered by the fan is 30% to 60% less in reverse than when operating in the normal forward mode.

Peter Iverson's The Plains Indians of the Twentieth Century is an attempt to document some of contemporary Plains Indian life. Iverson's collaborators include a number of well-known writers on Indian history and social issues, but their contributions are drawn from previously published works rather than being written for this anthology.

The article describes a water basin with dimensions 7 m x 4 m x 4 m, which was constructed for measurements with water-borne sound. The walls of this basin are coated with absorbers effective in the frequency range from 5 to 70 kc. These broadband absorbers consist of a system of parallel, wedge-shaped rubber plates made up of three layers of rubber glued together. The center sheet is perforated with circular holes (diameter 4 mm, hole density 4%). There are three types of wedges differing in length (7, 15, and 20 cm) covering the frequency range from 5 to 70 kc. The reflection factor related to amplitude remains below 10% in this frequency range. The excellent acoustical properties of the anechoic measuring basin are confirmed by the very small standing wave ratio for all frequencies., Trans. of Acustica (Switzerland) v10 p281-287 1960.

IT IS SHOWN THAT THE ATTENUATION OF SOUND IN ABSORBING DUCTS WITH SUPERIMPOSED FLOW IS DEPENDENT IN A HIGH DEGREE ON THE DIRECTION OF THE FLOW AND ITS VELOCITY. The change of attenuation is caused by a convective variation of the acoustic wavelength, by a nonlinear variation of the characteristic constants of the absorber, and by a deformation of the wave fronts in the profile of the mean flow. These changes can be calculated and are in good agreement with the experimental results. In a duct coated with undamped Helmholtz resonators the mechanism of sound amplification is based on the interaction between the sound wave and the turbulence. The conversion of kinetic flow energy into acoustic energy is performed by synchronization of turbulence. For appropriate values for flow velocity and signal frequency a long-range stable wave of pseudo-sound takes place. Sound and pseudo-sound interact with one another at the necks of the resonators., See also Volume 1, AD0296946 and Volume 3, AD0296984.

Theoretical and experimental results on the interaction between sound and air flow in a duct for the following studies are presented: (1) signal amplification as related to size, shape, and position of periodically spaced Helmholtz resonators mounted in the walls of a duct; (2) extension of flow velocity and signal frequency parameters for a duct coated with a porous absorber; and (3) investigation of plate absorbers for their usefulness in wind tunnel applications. Results of these studies show, respectively: (1) the ratio of the Helmholtz resonator neck width to the spacing, for sound propagation in the flow direction, is an important factor; (2) the solution of a wave equation agrees with experimental measurements for frequencies having a wavelength greater than and comparable to the duct diameter; and 993) the attenuation is dependent of the type of plate absorber (pliable, rigid, or resilient) and the flow velocity. The construction of a test duct for determining the sound field influence on the air flow boundary layer over a plate vibrating perpendicular to its surface is also reported., See also Volume 1, AD0296946 and Volume 2, AD0296985.

Several studies of the interaction between air flow and airborne sound in a duct were made. Three projects were investigated: (1) The excitation of boundary layer distortions in a laminar boundary layer by simulated oscillatory flexural waves was investigated. Results show boundary layer waves are excited whenever the phase velocity of the flexure wave is in the instability range of the phase velocity of boundary layer waves. (2) The propagation of a pressure pulse wave front and the acoustic impedance of porous absorbers are examined in ducts with air flow. Measurements prove the sound energy of the wave front is directed towards the walls and the absorber impedance becomes nonlinear when the absorber is penetrated by the flow. (3) the effect on the acoustic radiation impedance of an orifice with flow discharge restricted by fences and diaphragms was investigated. The acoustic resistance was shown to increase at low frequencies due to the restrictions.

The report briefly summarizes experiments during 1963-64 on the interaction between subsonic airflow and airborne sound in a duct. Also summarized are the results of the following four experiments conducted in 1965. The first experiment investigates the effect of the wall impedance on the stability and phase velocity of boundary layer waves. Measurements revealed a step in the dispersion curve of the flow velocity; this agrees with the dispersion curve of the sound velocity for a transition from capactive to inductive wall impedance. The second experiment investigates a flow boundary layer modified by sinusoidal suction (as opposed to stationary suction) through a porous plate imbedded in the wall of a duct. The alternating motions present in the suction elements excite boundary layer disturbances which may lead to a quicker transition into turbulence as compared to stationary suction. The third experiment was performed to improve the stability of a flow boundary layer by the application of an appropriate wall impedance. It was concluded that the real part of the impedance must be below 0.2 rho c. The final and most detailed experiment investigates the reflection coefficient of cross-sectional area changes and apertures in a tube with sound superimposed on an air flow. Smooth cross-sectional transitions show no acoustical or flow losses, whereas abrupt area changes cause flow separation, turbulence, and flow losses, all of which are associated with acoustic losses. These losses are described as an ohmic resistance which is added to the impedance of the transition. (Author), See also AD-669 358.

The report presents the results of three experimental studies on the interaction between air flow and airborne sound in a duct. The first experiment concerns the excitation and suppression of boundary-layer distortions (created by flexural wave-like wall oscillations). Mathematical approximations show and experimental results confirm that the stability of the boundary layer is shifted to higher Reynolds numbers by the flexural wave. The second experiment relates the boundary-layer (produced by static suction) stabilization to the sound field influencing it. Results show that the particle velocity of sound penetrating a porous section of the wall leads to an increase of boundary-layer distortions and that this effect could be suppressed when the flow velocity of the static suction exceeded a threshold value. The final experiment shows the influence of a superimposed air flow on the acoustic impedance of orifices terminating a tube and of constriction, enlargements, and nozzles within a tube. Results show that if the frequency is scaled according to the Mach number, then the ratio between the reflection coefficient gamma pm at Mach number M and the reflection coefficient at zero flow velocity gamma po is independent from the frequency. (Author), See also AD-669 085.

This report, Volume IV, presents the results (1961-1962) of several studies of the interaction between air flow and airborne sound in a duct. Three projects are discussed: (1) Part A: The effects of various sound fields on the excitation of the boundary layer of a flat plate are discussed relative to the stagnation point and the boundary layer itself. Boundary layer distortions are shown to be a function of the sound signal and flow velocity. (2) Part B: The change in the cross-sectional distribution of the sound pressure in an absorbent duct with air flow is examined with respect to the shape of the velocity profile of the flow. Even for wavelengths greater than the boundary layer thickness the sound pressure increased at the absorbing walls. (3) Part C: The dependence of the acoustic radiation impedance of a tube orifice during flow conditions is investigated as a function of the flow velocity and turbulence level. Results show that as the flow increases the radiation impedance decreases., Report on Biomechanics of Aerospace Operations.

1939 snow vacation near Cain ranch, LeeVining., June Lake 1939, Zelda, Gertrude; Virginia Donahue; Augie Hess; Crestview, California Revealed

Papers, Addresses, Reports: The Mucous Membrane of the Nose (Address of the Retiring President); The Endocrine Glands; Extract From the Report of the Secretary (Agriculture); Preliminary Studies in milk; Extract From the Report of the Section Chairman (Anthropology); Evidences of Woodland Culture at Mossville; Archeology of Western Kentucky; Preliminary Factors in the Use of Tree Rings to Date Mounds of the Mississippi Valley; Indian Camp Sites Along the Mackinaw River Near State Route 51; Evolution of Banner-stones; The Teeth and Bones of the Mound Builders as Related to Their Diet; Archeological Survey of Peoria County; An Interesting Anthropological Find From the Lake Michigan Region; The Evolution of the Mouth; Extract From the Report of the Section Chairman (Botany); Influence of Certain Organic Substances Upon the Growth Behavior of Excised Root Tips; Sample-plot Statistics in University Woods; Floral Zones in the Mountains of Southern Mexico; Was There an Outbreak of Bacterial Wilt of Corn in Central Illinois in 1891 and 1892?; An Interesting Preservation of Color in the Algae and Certain Fungi; Reduction in the Number of Trees in Maturing Pine Forest; Barrens Vegetation in Illinois; A Comparative Study of Bogs on Cary and Tazewell Drift; Extract From the Report of the Section Chairman (Chemistry); Some Interesting Methods of Balancing Oxidation-reduction Equations; Chemistry in Highway Construction; Some Anomalous Properties of Organic Fluorine Compounds; Corrosion Characteristics of SiO2-Al2-O3-CaO-MgO Glasses; The Natural Chemical Resources of Southern Illinois; Titanium-Hydrogen Peroxide Compounds; Present and Future Energy Sources; Some Remarks on the Coal Testing Laboratory as Related to Modern Coal Industry; Acid Catalysis in Liquid Ammonia; Demonstration of Cold Light; Effects on Corn and Wheat Starch Gels Produced by Pretreating the Starches with Freezing or With Chemical Reagents; Putting Thrills into Laboratory Experiments; The Position o