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We report the recent development of our new method to effectively eliminate the DI-effect by directly measuring the declination (D) and inclination (I) at the vicinity of a scalar magnetometer sensor. The practical utility of the method has been corroborated by using total intensity data (2007-2022) obtained from the twin sensors of Miharayama-Kita (MIK) magnetic station on Izu-Oshima Island. We also discuss the essential importance of acquiring both the D and I at every observation point of scalar magnetometer sensor, and present a prospect of producing a new declino/inclinometer that would make the measurement easy enough for any observers to perform.

Observations of the total magnetic force (F) can be used to infer subsurface thermal activities at volcanoes. In order to extract magnetic variations due to volcanic activity, it is common to take a difference between F near active areas and a reference point at some distance. However, an apparent variation called “orientation effect” emerges in the F difference, if there is a difference in the directions of magnetic field at those two points. The orientation effect associated with the geomagnetic secular variation can yield an apparent trend in the F difference, which may lead to a misinterpretation of the subsurface thermal activity. We report on our new method to effectively eliminate the orientation effect by directly measuring the declination (D) and inclination (I) at the vicinity of a F-sensor. Relatively easy-to-use measuring instruments of D and I are developed by transforming a transit compass (with telescope) commercially available. They satisfy the accuracy requirement (0.1 degree) needed for correcting the orientation effect. We show practical utility of the method by introducing a case in which we successfully remove a false trend in F data acquired on a basaltic volcano, Izu-Oshima, Japan. Besides the direct measurement of D and I, a satellite magnetic model CHAOS-7 is used that gives the three components of local secular variation.We also present a prospect of producing a new declino/inclinometer using a three-axis magnetic sensor and a gyro acceleration sensor. They would make the measurement of D and I easy enough for any observers to perform., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

26th European Photovoltaic Solar Energy Conference and Exhibition; 2350-2353, For thin film Silicon solar cells, conversion efficiency improvement and cost reduction are essential in order to compete to the other types of solar cells. ULVAC has been developed amoruphus silicon (a-Si)/microcrystalline silicon (μc-Si )tandem solar cells for the solution. We presented 1.1m x 1.4 m size a-Si/μc-Si tandem junction module with stabilized output power 145W (conversion efficiency 10% aperture area)[1][2]. In this work, development progress for higher conversion efficiency is reported. For further improvement, not only the quality-up of the absorber layers but also the effective light management are necessary. One of light management method is using inter layer between top cell and bottom cell. Light of shorter wavwlength is reflected to top cell by inter layer, and quantum efficency of top cell increases without thickening top layer thckness. Another method is light scattering by front electrode TCO. We have tested various materials and TCO deposition process to increase light trapping effect. Incorporating these technologies, we have achieved 10.8% conversion efficency by a-Si/μc-Si tandem solar cell with our developed TCO.

We present a new method to estimate a core surface flow model with a relaxed tangential geostrophy (TG) constraint. Ageostrophic flows, owing their presence to the magnetostrophic balance at the core surface, are allowed in our modeling as far as they are consisitent with the radial component of vorticity equation in the assumption of insulating mantle. We derive a radial vorticity (RV) constraint for the flow in the spherical harmonic domain and implement it in the least-square inversion of the latest core field model GRIMM-2 for temporally continuous core flow models (2000.0-2010.0). Comparing the flows inferred under the TG and RV constraints, we show that the number of degree of freedom of poloidal flow is notably increased by admitting the ageostrophic flow compatible with the RV constraint. The GRIMM-2 secular variation (SV) is accordingly easier to explain, so using the RV constraint allows a simpler spatial morphology of subsequent flow model. We find that the fit to the SV is significantly improved by the presence of zonal poloidal flow, the ageostrophic flow effectively producing the SV through the advection of axial dipole field. The correlation between the predicted and observed length-of-day variations are comparably reasonable under the TG and RV constraints. We also estimate flow models imposing the RV constraint together with another dynamical constraint: purely toroidal (PT) flow or helical flow constraint. For the PT case we cannot find any flow solution explaining the SV, while a barely acceptable model exists for the other case. The poor compatibility between the RV and PT constraints seems to arise from the absence of zonal poloidal flows. The PT flow assumption is very likely to be ruled out when the radial magnetostrophic vorticity balance is taken into account, even if otherwise consistent with magnetic observations.

25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 2713-2715, Thin-film silicon solar cells are known to be able to improve the conversion efficiency of multijunction solar cells with different band gap. Amorphous silicon (a-Si) and microcrystalline silicon (mc-Si) double junction thin-film solar cells can be obtained conversion efficiency of more than 9% and be significantly improved conversion efficiency compared to a-Si single junction thin-film solar cells. Last year, ULVAC released the new PECVD system named CIM-1400 for mc-Si deposition with the concept of high-throughput and low-cost production, and developed a-Si/mc-Si tandem turnkey line. ULVAC realized tandem junction solar module with initial power output of 150W and stabilized power output of 135W produced with CIM-1400. ULVAC introduces its further approach to efficiency improvement of thin-film solar cell. Topics to be introduced are ULVAC’s approach to stabilized output 145W on commercial production basis, film configuration of a-Si/mc-Si tandem junction solar module and optimization results with a-Si deposition system (CCV-1400) and CIM-1400 as well as development progress of tandem junction solar module.

24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany; 2317-2319, Over the years, ULVAC kept developing and studying plasma enhanced chemical vapor deposition (PECVD) technology time by time. And our system changed from small load-lock type equipment to horizontal inline type equipment and then to vertical type in-line PECVD for mass production scale in the ’90. Recent solar market growing changed the equipment business dramatically, and it created a new business model called “turnkey”. Today the market demands more high output power modules and lower manufacturing costs for thin-film silicon solar cells. Therefore we developed microcrystalline silicon depositing technology for amorphous silicon (a-Si) and microcrystalline silicon (uc-Si) double junction thin film solar cells in production level. We introduced more than 100W output power by 1.54m2 a-Si single junction thin film solar cells. And this new technology will increase 30% or more of output power with a reasonable cost.