45 research outputs found

    Effect of drying on the reproducibility of DIAGNOdent to detect caries-like lesions

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    The aim of this study was to verify the drying effect on the reproducibility of DIAGNOdent (Dd) devices to detect caries-like lesions. Three areas were created in each of the 34 bovine incisors: sound (S), demineralized (DE) and remineralized (RE). One examiner measured each area with two Dd devices (denominated X and Y), twice under humid, and twice under dry condition. Intra-rater agreement according each device and inter-device agreement were estimated by kappa statistics (k). Intra-rater agreement for device Y was substantial under humid (k DE=0.68 and k RE+S=0.68) and dry condition (k DE=0.64 and k RE+S=0.67). For device X, it was substantial under humid condition (k DE=0.57 and k RE+S=0.49), and it was almost perfect after air drying (k DE=1.0 and kRE+S=1.0). Inter-device agreement was slight (k =0.17) under humid condition, and it was substantial under dry condition (k =0.62). As reproducibility increased under dry condition, drying is advised to detect caries-like lesions on free smooth surfaces when different devices are used.Este estudo verificou o efeito da secagem sobre o resultado de reprodutibilidade de aparelhos laser DIAGNOdent (Dd) no diagnóstico de cárie artificial. Três áreas foram produzidas em cada um dos 34 incisivos bovinos: hígida (S), desmineralizada (DE) e remineralizada (RE). Um examinador mediu cada área com dois aparelhos Dd (denominados X e Y), sendo duas vezes sob a condição úmida e duas vezes sob a condição seca. A concordância intra-examinador segundo cada aparelho, e a concordância entre aparelhos foram estimadas por meio da estatística kappa (k). A reprodutibilidade intra para o aparelho Y foi substancial sob a condição úmida (kDE=0,68 e k RE+S=0,68) e seca (k DE=0,64 e k RE+S=0,67). Para o aparelho X, a concordância foi substancial sob a condição úmida (kDE=0,57 e k RE+S=0,49) e foi quase perfeita após a secagem (kDE=1,0 e k RE+S+1,0). A concordância entre aparelhos foi fraca (k=0,17) na condição úmida, porém foi substancial na condição seca (k=0,62). Como a reprodutibilidade foi melhor sob a condição seca, a secagem da superfície dentária é aconselhada para se detectar lesões de cárie incipientes em superfícies lisas livres, quando mais de um aparelho é utilizado no diagnóstico

    Status report on emerging photovoltaics

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    \ua9 2023 Society of Photo-Optical Instrumentation Engineers (SPIE).This report provides a snapshot of emerging photovoltaic (PV) technologies. It consists of concise contributions from experts in a wide range of fields including silicon, thin film, III-V, perovskite, organic, and dye-sensitized PVs. Strategies for exceeding the detailed balance limit and for light managing are presented, followed by a section detailing key applications and commercialization pathways. A section on sustainability then discusses the need for minimization of the environmental footprint in PV manufacturing and recycling. The report concludes with a perspective based on broad survey questions presented to the contributing authors regarding the needs and future evolution of PV

    Heuristische Suche in der KI, von Branch-and-Bound zum A*-Algorithmus

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    SIGLETIB Hannover: RN 4049(57) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

    Inverted Metamorphic III–V Triple-Junction Solar Cell with a 1 eV CuInSe 2

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    A new triple-junction solar cell (3J) design exploiting the highly absorptive I–III–VI chalcopyrite CuInSe2 material is proposed as an alternative to III–V semiconductor 3J solar cells. The proposed structure consists of GaInP (1.9 eV)/Ga(In)As (1.4 eV)/CuInSe2 (1 eV) which can be grown on a GaAs substrate in an inverted manner using epitaxial lift-off techniques. To lattice-match epitaxial CuInSe2 to Ga(In)As, a compositionally graded buffer region composed of GaxIn1−xP is used. The modeling and simulation of the device include the effects of threading dislocations on minority carrier lifetimes in the metamorphic buffer and bottom subcell active region. Studies focus on device performance under standard testing conditions and concentrated illumination. The results are compared to a reference lattice mismatched 3J composed of GaInP (1.9 eV)/Ga(In)As (1.4 eV)/GaInAs (1 eV) and to a lattice matched 3J composed of GaInP (1.9 eV)/Ga(In)As (1.4 eV)/Ge (0.67 eV). The advantage of CuInSe2 is its higher absorption coefficient, which requires only 1 μm of active material compared to 4 μm of GaInAs in the bottom subcell of the reference lattice mismatched cell. The proposed design reaches an efficiency of 32.6% under 1 sun illumination at 300 K with 105 cm−2 threading dislocations and 39.6% at 750 suns

    Microelectronic Engineering

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    NRC publication: Ye

    Red-Emitting Semiconductor Quantum Dot Lasers

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    Visible-stimulated emission in a semiconductor quantum dot (QD) laser structure has been demonstrated. Red-emitting, self-assembled QDs of highly strained InAlAs have been grown by molecular beam epitaxy on a GaAs substrate. Carriers injected electrically from the doped regions of a separate confinement heterostructure thermalized efficiently into the zero-dimensional QD states, and stimulated emission at sim 707 nanometers was observed at 77 kelvin with a threshold current of 175 milliamperes for a 60-micrometer by 400-micrometer broad area laser. An external efficiency of sim 8.5 percent at low temperature and a peak power greater than 200 milliwatts demonstrate the good size distribution and high gain in these high-quality QDs.NRC publication: Ye
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