4,123 research outputs found
Bimodal Counting Statistics in Single Electron Tunneling through a Quantum Dot
We explore the full counting statistics of single electron tunneling through
a quantum dot using a quantum point contact as non-invasive high bandwidth
charge detector. The distribution of counted tunneling events is measured as a
function of gate and source-drain-voltage for several consecutive electron
numbers on the quantum dot. For certain configurations we observe
super-Poissonian statistics for bias voltages at which excited states become
accessible. The associated counting distributions interestingly show a bimodal
characteristic. Analyzing the time dependence of the number of electron counts
we relate this to a slow switching between different electron configurations on
the quantum dot
Switching our core values from taking to giving
In his address, Fricke urged members of the Class of 2009 to find value in what they give to society, not what they take
GM1 Softens POPC Membranes and Induces the Formation of Micron-Sized Domains
The influence of the glycolipid GM1 on the physical properties of POPC membranes was studied systematically by using different methods applied to giant and large unilamellar vesicles. The charge per GM1 molecule in the membrane was estimated from electrophoretic mobility measurements. Optical microscopy and differential scanning calorimetry were employed to construct a partial phase diagram of the GM1/POPC system. At room temperature, phase separation in the membrane was detected for GM1 fractions at and above ∼5 mol %, whereby GM1-rich gel-like domains were observed by fluorescent microscopy. Fluctuation analysis, vesicle electrodeformation, and micropipette aspiration were used to assess the bending rigidity of the membrane as a function of GM1 content. In the fluid phase, GM1 was shown to strongly soften the bilayer. In the region of coexistence of fluid and gel-like domains, the micropipette aspiration technique allowed measurements of the bending rigidity of the fluid phase only, whereas electrodeformation and fluctuation analysis were affected by the presence of the gel-phase domains. The observation that GM1 decreased the bilayer bending rigidity is important for understanding the role of this ganglioside in the flexibility of neuronal membranes
Checklist of the fishes of New Caledonia, and their distribution in the Southwest Pacific Ocean (Pisces)
A checklist of the fishes of New Caledonia is presented. A total of 2328 species in 246 families have been recorded from the region. Eight of these species are not native, but have been introduced. Five fish families are represented only by introduced species. The native fish fauna of New Caledonia therefore consists of 2320 species in 241 families. The largest families are the Gobiidae, Labridae, Pomacentridae, Serranidae, Apogonidae, Blenniidae, Macrouridae, Myctophidae and Muraenidae. The freshwater fish fauna is dominated by the families Gobiidae, Eleotridae, Anguillidae and Mugilidae. A total of 61 species represent new records from New Caledonia. The fish fauna from New Caledonia includes a total of 125 species occurring in freshwater (plus eight introduced species), 266 (plus two introduced) species in transitional (brackish) waters, and 2320 marine species. The detailed geographical distribution of the New Caledonian fish species including the southern submarine ridges (Lord Howe Island, Norfolk Island, New Zealand) is provided. Among the New Caledonian marine species, 905 are recorded from the East Coral Sea including Chesterfield Islands, 193 from the New Caledonian basin, 1860 from the Grande Terre group, 85 from the Norfolk Ridge, and 1029 from the Loyalty Ridge including Loyalty Islands. New Caledonia has a considerable endemic element of 107 species (4.6 % of the total native species)
Energy Consumption and Product Throughput of Glass-Doored and Open Refrigerated Display Cases in Supermarkets [abstract]
Only abstract of poster available.Track III: Energy InfrastructureRefrigerated display cases are utilized by supermarkets to store and display food products in a manner that extends food shelf life and ensures food safety. Supermarkets operate their refrigeration systems continuously to maintain proper food storage conditions. Continual operation of this refrigeration equipment on a nationwide scale accounts for approximately 0.33 quads/yr of electrical energy. Infiltration accounts for over 70% of the refrigeration load in open refrigerated display cases. Clearly, an increase in the energy efficiency of refrigerated display cases will result in significantly reduced energy consumption and cost.
Thus, the objective of this project is to compare a typical open refrigerated display case to a typical glass-doored refrigerated display case with the aim of quantifying the following:
• The difference in overall energy consumption between the cases.
• The normalized difference in food product sales between the cases.
Two supermarkets are being used as test sites, which are similarly situated to ensure that climate, weather, time-of-year and economic conditions of the shoppers are comparable. One supermarket will receive an open refrigerated display case and the other will receive a doored refrigerated display case. Each refrigerated display case will be a medium temperature, self-service prepackaged deli or beverage case between 8 and 25 nominal linear feet.
The thermal performance and product sales of each refrigerated display case will be monitored. Automated data logging systems will be used to measure quantities such as refrigeration load, voltage, current, temperature, humidity and pressure. Product sales for each refrigerated display case and total store product sales will be tracked using Stock Keeping Units (SKUs) and the supermarkets' computerized Point of Sale (POS) system. The resulting data will be analyzed to determine the difference in energy consumption and product sales between the two refrigerated cases
Synchiropus sechellensis Regan, 1908 (Teleostei: Callionymidae), a new Lessepsian migrant in the Mediterranean Sea
A new Lessepsian migrant, Synchiropus sechellensis Regan, 1908 (Teleostei: Callionymidae), was recorded for the first time by a single male specimen, during bottom trawl operation in the Mediterranean Sea
First record of the reticulated dragonet, Callionymus reticulatus Valenciennes, 1837 (Actinopterygii: Callionymiformes: Callionymidae), from the Balearic Islands, western Mediterranean
The reticulated dragonet, Callionymus reticulatus, was originally described based on a single specimen, the holotype from Malaga, Spain, south-western Mediterranean, probably collected before 1831. The holotype is now disintegrated; the specific characteristics are no longer discernible. The species was subsequently recorded from several north-eastern Atlantic localities (Western Sahara to central Norway), but missing in the Mediterranean.
Specimens of C. reticulatus were observed and collected during two cruises in 2014 and 2016 in the Balearic Islands off Mallorca and Menorca. The collected specimens (8 females) have been deposited in the collection of the Hebrew University of Jerusalem (HUJ). All individuals of C. reticulatus were collected from beam trawl samples carried out during the DRAGONSAL0914 in September 2014, and during the MEDITS_ES05_16 bottom trawl survey in June 2016, on shelf and slope bottoms around the Balearic Islands. Both surveys used a ‘Jennings’ beam trawl to sample the epi-benthic communities, which was the main objective of the DRAGONSAL0914 and a complementary objective in the MEDITS_ES05_16. The ‘Jennings’ beam trawl has a 2 m horizontal opening, 0.5 m vertical opening and a 5 mm diamond mesh in the codend. Trawls had duration of 1 to 3 min of effective sampling (bottom time) at a speed of 2 knots. Catches were sorted out to species and standardized abundances of callionymid species (individuals per 500 m2) were obtained by calculating the sampled surface (distance covered × beam trawl horizontal opening). Callionymus reticulatus is recorded from the Balearic Islands for the first time; the specimens are described and illustrated. The new record confirms that the species is still extant in the Mediterranean. A key to Mediterranean callionymid fishes is provided to distinguish C. reticulatus from other species of the family in the area. The callionymid fish fauna of the Mediterranean now comprises 11 species, including three Lessepsian migrants originating from the Red SeaVersión del edito
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