Theory of Feshbach molecule formation in a dilute gas during a magnetic field ramp

Starting with coupled atom-molecule Boltzmann equations, we develop a simplified model to understand molecule formation observed in recent experiments. Our theory predicts several key features: (1) the effective adiabatic rate constant is proportional to density; (2) in an adiabatic ramp, the dependence of molecular fraction on magnetic field resembles an error function whose width and centroid are related to the temperature; (3) the molecular production efficiency is a universal function of the initial phase space density, the specific form of which we derive for a classical gas. Our predictions show qualitative agreement with the data from [Hodby et al, Phys. Rev. Lett. {\bf{94}}, 120402 (2005)] without the use of adjustable parameters

Tone of voice helps learning the meaning of novel adjectives [Abstract]

To understand spoken words listeners have to cope with seemingly meaningless variability in the speech signal. Speakers vary, for example, their tone of voice (ToV) by changing speaking rate, pitch, vocal effort, and loudness. This variation is independent of "linguistic prosody" such as sentence intonation or speech rhythm. The variation due to ToV, however, is not random. Speakers use, for example, higher pitch when referring to small objects than when referring to large objects and importantly, adult listeners are able to use these non-lexical ToV cues to distinguish between the meanings of antonym pairs (e.g., big-small; Nygaard, Herold, & Namy, 2009). In the present study, we asked whether listeners infer the meaning of novel adjectives from ToV and subsequently interpret these adjectives according to the learned meaning even in the absence of ToV. Moreover, if listeners actually acquire these adjectival meanings, then they should generalize these word meanings to novel referents. ToV would thus be a semantic cue to lexical acquisition. This hypothesis was tested in an exposure-test paradigm with adult listeners. In the experiment listeners' eye movements to picture pairs were monitored. The picture pairs represented the endpoints of the adjectival dimensions big-small, hot-cold, and strong-weak (e.g., an elephant and an ant represented big-small). Four picture pairs per category were used. While viewing the pictures participants listened to lexically unconstraining sentences containing novel adjectives, for example, "Can you find the foppick one?" During exposure, the sentences were spoken in infant-directed speech with the intended adjectival meaning expressed by ToV. Word-meaning pairings were counterbalanced across participants. Each word was repeated eight times. Listeners had no explicit task. To guide listeners' attention to the relation between the words and pictures, three sets of filler trials were included that contained real English adjectives (e.g., full-empty). In the subsequent test phase participants heard the novel adjectives in neutral adult-directed ToV. Test sentences were recorded before the speaker was informed about intended word meanings. Participants had to choose which of two pictures on the screen the speaker referred to. Picture pairs that were presented during the exposure phase and four new picture pairs per category that varied along the critical dimensions were tested. During exposure listeners did not spontaneously direct their gaze to the intended referent at the first presentation. But as indicated by listener's fixation behavior, they quickly learned the relationship between ToV and word meaning over only two exposures. Importantly, during test participants consistently identified the intended referent object even in the absence of informative ToV. Learning was found for all three tested categories and did not depend on whether the picture pairs had been presented during exposure. Listeners thus use ToV not only to distinguish between antonym pairs but they are able to extract word meaning from ToV and assign this meaning to novel words. The newly learned word meanings can then be generalized to novel referents even in the absence of ToV cues. These findings suggest that ToV can be used as a semantic cue to lexical acquisition. References Nygaard, L. C., Herold, D. S., & Namy, L. L. (2009) The semantics of prosody: Acoustic and perceptual evidence of prosodic correlates to word meaning. Cognitive Science, 33. 127-146

Undersøkelse av resipientforholdene ved Narestø, Arendal kommune

Rapporten beskriver resipientforholdene i Narestøfjorden, og vurderer mulige konsekvenser av økning i det kommunale utslippet fra 70 pe til 3340 pe. Det er gjort undersøkelser av hydrografi (temperatur og saltholdighet), næringssalter, strøm, gruntvannsorganismer og bløtbunnsfauna. Videre er det foretatt beregninger av innlagringsdyp og fortynningsgrad ved ulike utslippsmengder og -dyp. Resultatene viste god vannutskiftning i overflatelaget ned til ca. 10 meter (oppholdstid 3-4 timer). Bunnvannet var ikke stagnerende, men hadde en noe lengre oppholdstid enn overflatevannet, ca. 1-2 døgn. Det var ingen tegn til effekter av dagens utslipp på strandsonen eller bløtbunnsfaunaen. Selv om det var mindre vannutskiftning i dypvannet, anbefales en utslippsløsning med utslippsdyp på 36 m, rørdiameter 150 mm og Y-formet ende-rør for det nye utslippet. Utslippet vil da innlagres i ca. 22 meters dyp, og det vil være liten sannsynlighet for gjennomslag til overflaten. Overflatevannet har i utgangspunktet noe høyt næringsinnhold

Learning of adjectival word meaning through tone of voice [Abstract]

Speakers express word meaning through systematic but non-canonical acoustic variation of tone of voice (ToV), i.e., variation of speaking rate, pitch, vocal effort, or loudness. Words are, for example, pronounced at a higher pitch when referring to small than to big referents. In the present study, we examined whether listeners can use ToV to learn the meaning of novel adjectives (e.g., “blicket”). During training, participants heard sentences such as “Can you find the blicket one?” spoken with ToV representing hot-cold, strong-weak, and big-small. Participants’ eye movements to two simultaneously shown objects with properties representing the relevant two endpoints (e.g., an elephant and an ant for big-small) were monitored. Assignment of novel adjectives to endpoints was counterbalanced across participants. During test, participants heard the sentences spoken with a neutral ToV, while seeing old or novel picture pairs varying along the same dimensions (e.g., a truck and a car for big-small). Participants had to click on the adjective’s referent. As evident from eye movements, participants did not infer the intended meaning during first exposure, but learned the meaning with the help of ToV during training. At test listeners applied this knowledge to old and novel items even in the absence of informative ToV

Tone of voice guides word learning in informative referential contexts

Listeners infer which object in a visual scene a speaker refers to from the systematic variation of the speaker's tone of voice (ToV). We examined whether ToV also guides word learning. During exposure, participants heard novel adjectives (e.g., “daxen”) spoken with a ToV representing hot, cold, strong, weak, big, or small while viewing picture pairs representing the meaning of the adjective and its antonym (e.g., elephant-ant for big-small). Eye fixations were recorded to monitor referent detection and learning. During test, participants heard the adjectives spoken with a neutral ToV, while selecting referents from familiar and unfamiliar picture pairs. Participants were able to learn the adjectives' meanings, and, even in the absence of informative ToV, generalise them to new referents. A second experiment addressed whether ToV provides sufficient information to infer the adjectival meaning or needs to operate within a referential context providing information about the relevant semantic dimension. Participants who saw printed versions of the novel words during exposure performed at chance during test. ToV, in conjunction with the referential context, thus serves as a cue to word meaning. ToV establishes relations between labels and referents for listeners to exploit in word learning

Vannstandsendringer i Vågsbøpollen og Ådlandsstraumen som følge av kanalbygging. Målinger og befaringer, juli-oktober 1998

Høsten 1996 ble det åpnet en ny båtkanal mellom Vestrepollen og Vågsbøpollen i Fana. Kanalen har medført økte tidevannsforskjeller og bedre vannutskifting i Vågsbøpollen. Tidligere var Ådlandsstraumen eneste forbindelse mellom Vågsbøpollen og sjøen. På grunn av kanalen er vanngjennomstrømmingen i Ådlandsstraumen blitt mindre, og lavvann-nivået er senket. For å dokumentere eventuelle effekter som følge av kanalen gjennomførte NIVA i samarbeid med UiB et prosjekt sommeren 1998 for å registrere biologiske endringer i strandsonen. I tillegg ble det gjort målinger av vannstand og utført modellsimuleringer. Den biologiske kartleggingen ga ingen entydige verdier for endringer i høyvann- og lavvannsnivå, men indikerer lavvannssenking på 20-30 cm i Vågsbøpollen. Vannstandsmålingene viser en økning av vannstandsamplituden på inntil 50 cm (i det vesentligste lavvanns-senking) og en middel amplitudeendring på 25 cm. I Ådlandsstraumen oppstrøms den nederste innsnevringen er det tale om senking av vann-nivået ved fjære sjø på inntil 29 cm i forhold til tidligere. Dette forekommer kun kortvarig ved spring lavvann. Lavvanns-senking med 25 cm eller mer i dette området skjer i følge beregningene i 1,2% av tiden, tilsvarende mange korte perioder med lavvann med samlet varighet på 8,6 timer i løpet av en måned

Large-angle Electron-photon Coincidence Experiment In Atomic Hydrogen

1s-2p excitation in hydrogen has been studied by observing the angular correlation of Lyman photons detected in coincidence with inelastically scattered electrons at 54.4 eV incident energy. The electron scattering angles ranged from 10°to 133°; the results at scattering angles larger than 20°cannot be explained by currently available theories. © 1980 The American Physical Society

Anleggsarbeid ved Trengereid kraftverk. Rapport fra overvåking av temperatur og oksygen i samband med ombyggingen i 1995-1996

Fra sommeren 1995 og til juni 1996 var kraftstasjonen på Trengereid i Vaksdal kommune, Hordaland, gjenstand for omfattende ombygging, som inkluderte omlegging og ombygging av trase/rørgate fra Skulstadvatn og ned til kraftstasjonen ved Sørfjorden. Om lag 6.000 m³ steinmasse ble sprengt eller boret ut. NIVA gjennomførte et overvåkingsprogram i anleggsområdet og i fjorden ved Trengereid Fisk A/S sitt matfiskanlegg, for å sikre målinger/opplysninger i tilfelle negative episoder, og for å framskaffe grunnlagsdata for evt. seinere bedømming av temperaturendringer i inntaksvannet til settefiskanlegget. Arbeidet medførte en del partikkelforurensing i Skulstadelva, som er hovedvannkilde for Trengereid Smolt A/S sitt smoltanlegg. Rapporten gir en oversikt over utførte aktiviteter, og presenterer og oppsummerer måleresultatene.BKK v/Gudmund Trætteber