39 research outputs found
Evidence of sound production by spawning lake trout (Salvelinus namaycush) in lakes Huron and Champlain
Two sounds associated with spawning lake trout (Salvelinus namaycush) in lakes Huron and Champlain were characterized by comparing sound recordings with behavioral data collected using acoustic telemetry and video. These sounds were named “growls” and “snaps” and were heard on lake trout spawning reefs, but not on a nonspawning reef, and were more common at night than during the day. Growls also occurred more often during the spawning period than the prespawning period, while the trend for snaps was reversed. In a laboratory flume, sounds occurred when male lake trout were displaying spawning behaviors: growls when males were quivering and parallel swimming and snaps when males moved their jaw. Combining our results with the observation of possible sound production by spawning splake (Salvelinus fontinalis × Salvelinus namaycush hybrid) provides rare evidence for spawning-related sound production by a salmonid or any other fish in the superorder Protacanthopterygii. Further characterization of these sounds could be useful for lake trout assessment, restoration, and control
A New Route to Fluorescent SWNT/Silica Nanocomposites: Balancing Fluorescence Intensity and Environmental Sensitivity
We investigate the relationship between photoluminescence (PL) intensity and
environmental sensitivity of surfactant-wrapped single walled carbon nanotubes
(SWNTs). SWNTs were studied under a variety of conditions in suspension as well
as encapsulated in silica nanocomposites, which were prepared by an efficient
chemical vapor into liquids (CViL) sol-gel process. The dramatically improved
silica encapsulation process described here has several advantages, including
fast preparation and high SWNT loading concentration, over other encapsulation
methods used to prepare fluorescent SWNT/silica nanocomposites. Further,
addition of glycerol to SWNT suspensions prior to performing the CViL sol-gel
process allows for the preparation of freestanding fluorescent silica xerogels,
which to the best of our knowledge is the first report of such nanocomposites.
Our spectroscopic data on SWNTs suspended in aqueous surfactants or
encapsulated in silica show that achieving maximum PL intensity results in
decreased sensitivity of SWNT emission response to changes imparted by the
local environment. In addition, silica encapsulation can be used to "lock-in" a
surfactant micelle structure surrounding SWNTs to minimize interactions between
SWNTs and ions/small molecules. Ultimately, our work demonstrates that one
should consider a balance between maximum PL intensity and the ability to sense
environmental changes when designing new SWNT systems for future sensing
applications
Surface-initiated growth of copper using isonicotinic acid-functionalized aluminum oxide surfaces
Isonicotinate self-assembled monolayers (SAM) were prepared on alumina surfaces (A) using isonicotinic acid (iNA). These functionalized layers (iNA-A) were used for the seeded growth of copper films (Cu-iNA-A) by hydrazine hydrate-initiated electroless deposition. The films were characterized by scanning electron microscopy (SEM), electron-dispersive X-ray spectroscopy, atomic force microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and advancing contact angle measurements. The films are Cu0 but with surface oxidation, and show a faceted morphology, which is more textured (Rq = 460 ± 90 nm) compared to the SAM (Rq = 2.8 ± 0.5 nm). In contrast, growth of copper films by SnCl2/PdCl2 catalyzed electroless deposition, using formaldehyde (CH2O) as the reducing agent, shows a nodular morphology on top of a relatively smooth surface. No copper films are observed in the absence of the isonicotinate SAM. The binding of Cu2+ to the iNA is proposed to facilitate reduction to Cu0 and create the seed for subsequent growth. The films show good adhesion to the functionalized surface
Design of value chains in volume-intensive market segments - exploiting economies of scale, scope and integration
Large suppliers of wood products and large industrial customers and mega-retailers experience
situations, where there are fewer potential partners for large-scale business agreements. The
customer-supplier relationships are moving in the direction of bilateral relationships between
large and resourceful suppliers and customers, with fewer options to play “the competitive
game”. Traditionally, the wood value chain has been characterized by aiming for economies of
scale. Wood products manufacturers have focused on high raw material recovery thus moving
towards larger and more efficient production units. The retailing business has moved in the
same direction as a consequence of the competitiveness on the end-user market with its focus on
price. Consequently, there are actors adopting a scope strategy aiming at differentiation in some
dimensions. There has thus been a build-up of large suppliers and retailers.
In this new competitive landscape, both suppliers and customers have to rethink their traditional
strategies and to design more complex value chains (and business models), often with more than
two partners involved. We describe a business case of a co-operation between one large
sawmilling company and one smaller wooden component manufacturer on the supplier side, and
a large mega-retailer on the customer side. The sawmilling company and mega-retailer have
strong large scale orientations, with solid finances and a focus on large volumes. The
manufacturer of wooden components is small-scale and not able to operate on its own as a
partner to the large customer.
The result of the study indicates the possibilities for large scale professional actors to opt for
economies of integration by introducing a third party. Agreements are negotiated and secured by
the large actors’ professionalism and size, and control of input material and market knowledge.
The flexibility and efficiency of producing and delivering adapted products are created by the
innovativeness of the small-scale component manufacturer, investing in niche markets. The
study therefore indicates a possible business option for actors in the presently scale-dominated
value chain
Molecular insights on aging and aqueous-phase processing from ambient biomass burning emissions-influenced Po Valley fog and aerosol
To study the influence of regional biomass burning emissions and secondary
processes, ambient samples of fog and aerosol were collected in the Po Valley
(Italy) during the 2013 Supersito field campaign. After the extent of
fresh vs. aged biomass burning influence was estimated from proton
nuclear magnetic resonance (1H NMR) and high-resolution time-of-flight
aerosol mass spectrometry (HR-ToF-AMS), two samples of fog water and two
samples of PM1 aerosol were selected for ultrahigh-resolution Fourier
transform ion cyclotron resonance mass spectrometry (FT-ICR MS) analysis.
Molecular compositions indicated that the water-soluble organic matter was
largely non-polymeric without clearly repeating units. The selected samples
had an atypically large frequency of molecular formulas containing nitrogen
and sulfur (not evident in the NMR composition) attributed to multifunctional
organonitrates and organosulfates. Higher numbers of organonitrates were
observed in aerosol, and higher numbers of organosulfates were observed in
fog water. Consistent with the observation of an enhanced aromatic proton
signature in the 1H-NMR analysis, the average molecular formula
double-bond equivalents and carbon
numbers were higher in the fresh biomass-burning-influenced samples. The
average O : C and H : C values from FT-ICR MS were higher in the samples
with an aged influence (O : C  =  0.50–0.58, and
H : C  =  1.31–1.37) compared to those with fresh influence
(O : C  =  0.43–0.48, and H : C  =  1.13–1.30). The aged fog had a
large set of unique highly oxygenated CHO fragments in the HR-ToF-AMS, which
reflects an enrichment of carboxylic acids and other compounds carrying acyl
groups, highlighted by the NMR analysis. Fog compositions were more oxidized
and SOA (secondary organic aerosol)-like than aerosols as indicated by
their NMR measured acyl-to-alkoxyl ratios and the observed molecular formula
similarity between the aged aerosol and fresh fog, implying that fog nuclei
must be somewhat aged. Overall, functionalization with nitrate and sulfate
moieties, in addition to aqueous oxidation, triggers an increase in the
molecular complexity in this environment, which is apparent in the FT-ICR MS
results. This study demonstrates the significance of the aqueous phase in
transforming the molecular chemistry of atmospheric organic matter and
contributing to secondary organic aerosol.</p
Evidence of sound production by spawning lake trout (Salvelinus namaycush) in lakes Huron and Champlain
Two sounds associated with spawning lake trout (Salvelinus namaycush) in lakes Huron and Champlain were characterized by comparing sound recordings to behavioral data collected using acoustic telemetry and video. These sounds were named growls and snaps, and were heard on lake trout spawning reefs, but not on a non-spawning reef, and were more common at night than during the day. Growls also occurred more often during the spawning period than the pre-spawning period, while the trend for snaps was reversed. In a laboratory flume, sounds occurred when male lake trout were displaying spawning behaviors; growls when males were quivering and parallel swimming, and snaps when males moved their jaw. Combining our results with the observation of possible sound production by spawning splake (Salvelinus fontinalis Ä‚ Salvelinus namaycush hybrid), provides rare evidence for spawning-related sound production by a salmonid, or any other fish in the superorder Protacanthopterygii. Further characterization of these sounds could be useful for lake trout assessment, restoration, and control.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
Systematic effects from black hole-neutron star waveform model uncertainties on the neutron star equation of state
We identify various contributors of systematic effects in the measurement of the neutron star (NS) tidal deformability and quantify their magnitude for several types of neutron star - black hole (NSBH) binaries. Gravitational waves from NSBH mergers contain information about the components' masses and spins as well as the NS equation of state. Extracting this information requires comparison of the signal in noisy detector data with theoretical templates derived from some combination of post-Newtonian (PN) approximants, effective one-body (EOB) models and %analytic fits to numerical relativity (NR) simulations. The accuracy of these templates is limited by errors in the NR simulations, by the approximate nature of the PN/EOB waveforms, and by the hybridization procedure used to combine them. In this paper, we estimate the impact of these errors by constructing and comparing a set of PN-NR hybrid waveforms, for the first time with NR waveforms from two different codes, namely, SpEC and SACRA, for such systems. We then attempt to recover the parameters of the binary using two non-precessing template approximants. We find that systematic errors are too large for tidal effects to be accurately characterized for any realistic NS equation of state model. We conclude that NSBH waveform models must be significantly improved if they are to be useful for the extraction of NS equation of state information or even for distinguishing NSBH systems from binary black holes