Thermoelectric materials by using two-dimensional materials with negative correlation between electrical and thermal conductivity

In general, in thermoelectric materials the electrical conductivity sigma and thermal conductivity kappa are related and thus cannot be controlled independently. Previously, to maximize the thermoelectric figure of merit in state-of-the-art materials, differences in relative scaling between sigma and kappa as dimensions are reduced to approach the nanoscale were utilized. Here we present an approach to thermoelectric materials using tin disulfide, SnS2, nanosheets that demonstrated a negative correlation between sigma and kappa. In other words, as the thickness of SnS2 decreased, sigma increased whereas kappa decreased. This approach leads to a thermoelectric figure of merit increase to 0.13 at 300 K, a factor similar to 1,000 times greater than previously reported bulk single-crystal SnS2. The Seebeck coefficient obtained for our two-dimensional SnS2 nanosheets was 34.7mVK(-1) for 16-nm-thick samples at 300 K.114330Ysciescopu

Depth resolved lattice-charge coupling in epitaxial BiFeO3 thin film

For epitaxial films, a critical thickness (t(c)) can create a phenomenological interface between a strained bottom layer and a relaxed top layer. Here, we present an experimental report of how the t(c) in BiFeO3 thin films acts as a boundary to determine the crystalline phase, ferroelectricity, and piezoelectricity in 60 nm thick BiFeO3/SrRuO3/SrTiO3 substrate. We found larger Fe cation displacement of the relaxed layer than that of strained layer. In the time-resolved X-ray microdiffraction analyses, the piezoelectric response of the BiFeO3 film was resolved into a strained layer with an extremely low piezoelectric coefficient of 2.4 pm/V and a relaxed layer with a piezoelectric coefficient of 32 pm/V. The difference in the Fe displacements between the strained and relaxed layers is in good agreement with the differences in the piezoelectric coefficient due to the electromechanical couplingope

The K2K SciBar Detector

A new near detector, SciBar, for the K2K long-baseline neutrino oscillation expe riment was installed to improve the measurement of neutrino energy spectrum and to study neutrino interactions in the energy region around 1 GeV. SciBar is a 'fully active' tracking detector with fine segmentation consisting of plastic scintillator bars. The detector was constructed in summer 2003 and is taking data since October 2003. The basic design and initial performance is presented.Comment: 7 pages, 4figures, Contributed to Proceedings of the 10th Vienna Conference on Instrumentation, Vienna, February 16-21, 200

SILAC-based proteomic quantification of chemoattractant-induced cytoskeleton dynamics on a second to minute timescale

Cytoskeletal dynamics during cell behaviours ranging from endocytosis and exocytosis to cell division and movement is controlled by a complex network of signalling pathways, the full details of which are as yet unresolved. Here we show that SILAC-based proteomic methods can be used to characterize the rapid chemoattractant-induced dynamic changes in the actin–myosin cytoskeleton and regulatory elements on a proteome-wide scale with a second to minute timescale resolution. This approach provides novel insights in the ensemble kinetics of key cytoskeletal constituents and association of known and novel identified binding proteins. We validate the proteomic data by detailed microscopy-based analysis of in vivo translocation dynamics for key signalling factors. This rapid large-scale proteomic approach may be applied to other situations where highly dynamic changes in complex cellular compartments are expected to play a key role

Enhanced anti-tumor effects of combined MDR1 RNA interference and human sodium/iodide symporter (NIS) radioiodine gene therapy using an adenoviral system in a colon cancer model

Using an adenoviral system as a delivery mediator of therapeutic gene, we investigated the therapeutic effects of the use of combined MDR1 shRNA and human NIS (hNIS) radioiodine gene therapy in a mouse colon xenograft model. In vitro uptake of Tc-99m sestamibi was increased approximately two-fold in cells infected with an adenovirus vector that expressed MDR1 shRNA (Ad-shMDR1) and I-125 uptake was 25-fold higher in cells infected with an adenovirus vector that expressed human NIS (Ad-hNIS) as compared with control cells. As compared with doxorubicin or I-131 treatment alone, the combination of doxorubicin and I-131 resulted in enhanced cytotoxicity for both Ad-shMDR1- and Ad-hNIS-infected cells, but not for control cells. In vivo uptake of Tc-99m sestamibi and Tc-99m pertechnetate was twofold and 10-fold higher for Ad-shMDR1 and Ad-hNIS-infected tumors as compared with tumors infected with a control adenovirus construct that expressed β-galactrosidase (Ad-LacZ), respectively. In mice treated with either doxorubicin or I-131 alone, there was a slight delay in tumor growth as compared to mice treated with Ad-LacZ. However, combination therapy with doxorubicin and I-131 induced further significant inhibition of tumor growth as compared with mice treated with Ad-LacZ. We have shown successful therapeutic efficacy of combined MDR shRNA and hNIS radioiodine gene therapy using an adenoviral vector system in a mouse colon cancer model. Adenovirus-mediated cancer gene therapy using MDR1 shRNA and hNIS would be a useful tool for the treatment of cancer cells expressing multi-drug resistant genes

Soundscape assessment: Towards a validated translation of perceptual attributes in different languages

The recently published ISO/TS 12913-2:2018 standard aims to provide researchers and practitioners around the world with a reliable questionnaire for soundscape characterization. The ISO Technical Specifications report protocols and attributes grounded in the soundscape literature, but only includes an English version. The applicability and reliability of these attributes in non-English speaking regions remains an open question, as research investigating translations of soundscape attributes is limited. To address this gap, an international collaboration was initiated with soundscape researchers from all over the world. Translation into 15 different languages, obtained through focus groups and panels of experts in soundscape studies, are proposed. The main challenges and outcomes of this preliminary exercise are discussed. The long-term objective is to validate the proposed translations using standardized listening experiments in different languages and geographical regions as a way to promote a widespread use of the soundscape attributes, both in academia and practice, across locations, populations and languages

Breathing silicon anodes for durable high-power operations

Silicon anode materials have been developed to achieve high capacity lithium ion batteries for operating smart phones and driving electric vehicles for longer time. Serious volume expansion induced by lithiation, which is the main drawback of silicon, has been challenged by multi-faceted approaches. Mechanically rigid and stiff polymers (e.g. alginate and carboxymethyl cellulose) were considered as the good choices of binders for silicon because they grab silicon particles in a tight and rigid way so that pulverization and then break-away of the active mass from electric pathways are suppressed. Contrary to the public wisdom, in this work, we demonstrate that electrochemical performances are secured better by letting silicon electrodes breathe in and out lithium ions with volume change rather than by fixing their dimensions. The breathing electrodes were achieved by using a polysaccharide (pullulan), the conformation of which is modulated from chair to boat during elongation. The conformational transition of pullulan was originated from its a glycosidic linkages while the conventional rigid polysaccharide binders have beta linkages.119201sciescopu

High-performance flexible perovskite solar cells exploiting Zn2SnO4 prepared in solution below 100 degrees C

Fabricating inorganic-organic hybrid perovskite solar cells (PSCs) on plastic substrates broadens their scope for implementation in real systems by imparting portability, conformability and allowing high-throughput production, which is necessary for lowering costs. Here we report a new route to prepare highly dispersed Zn2SnO4 (ZSO) nanoparticles at low-temperature (<100 degrees C) for the development of high-performance flexible PSCs. The introduction of the ZSO film significantly improves transmittance of flexible polyethylene naphthalate/indium-doped tin oxide (PEN/ITO)-coated substrate from similar to 75 to similar to 90% over the entire range of wavelengths. The best performing flexible PSC, based on the ZSO and CH3NH3PbI3 layer, exhibits steady-state power conversion efficiency (PCE) of 14.85% under AM 1.5G 100 mW . cm(-2) illumination. This renders ZSO a promising candidate as electron-conducting electrode for the highly efficient flexible PSC applications.ope

Spectral splitting photovoltaics using perovskite and wideband dye-sensitized solar cells

The extension of the light absorption of photovoltaics into the near-infrared region is important to increase the energy conversion efficiency. Although the progress of the lead halide perovskite solar cells is remarkable, and high conversion efficiency of &gt;20% has been reached, their absorption limit on the long-wavelength side is similar to 800 nm. To further enhance the conversion efficiency of perovskite-based photovoltaics, a hybridized system with near-infrared photovoltaics is a useful approach. Here we report a panchromatic sensitizer, coded DX3, that exhibits a broad response into the near-infrared, up to similar to 1100 nm, and a photocurrent density exceeding 30 mA cm(-2) in simulated air mass 1.5 standard solar radiation. Using the DX3-based dye-sensitized solar cell in conjunction with a perovskite cell that harvests visible light, the hybridized mesoscopic photovoltaics achieved a conversion efficiency of 21.5% using a system of spectral splitting.open0