Performance of a large aperture GEM-like gating device for the International Linear Collider

One of the potential problems of a Micro-Pattern Gaseous Detector (MPGD)-based Time Projection Chamber (TPC) is the Ion back Flow (IBF): ions generated through the avalanche amplification process flow back to the drift volume of the TPC and disarrange an electric field inside it. Consequently non-negligible degradation of azimuthal spatial resolution is caused due to this IBF. Meanwhile, it is necessary to collect primary ionized electrons to maintain intrinsic performance of the MPGDs. The MPGD based TPC is currently planned to be used as a central tracking detector of the International Large Detector (ILD), which is one of the detector concepts for the future International Linear Collider (ILC) project, and which requires fine azimuthal spatial resolution of less than 100 ${\rm \mu m}$ over the drift length of the TPC to attain high momentum resolution. Because of a unique beam structure of the ILC, the IBF is a critical issue for the realization of the ILD-TPC. Not only to suppress the ion back-flow to the drift volume, but also to allow the primary electrons pass through, a large aperture GEM-like gating device has been developed. Several bench tests for confirming the performance of the gating device have been conducted, besides that, beam test with the full detector module equipped with the gating device was carried out to verify the resolution that the full module can provide. As a result, it turned out that the developed gating device fulfills requirements for maintaining the performance of the MPGD based TPC, and it has sufficient performance for the central tracker of the ILD at the ILC.Comment: 2017 IEEE Nuclear Science Symposium Conference Recor

A Theory of Optimum Tariff Under Revenue Constraint.

This paper analyzes the revenue-constrained optimum tariff problem. When a fixed level of tax revenue has to be collected only from tariffs, an efficient resource allocation can not be achieved by any tariff structure. Thus we need to find the optimum tariff structure as the second best resource allocation.TAXATION ; TRADE ; ECONOMIC THEORY

Simplified methods for calculating photodissociation rates

Simplified methods for calculating the transmission of solar UV radiation and the dissociation coefficients of various molecules are compared. A significant difference sometimes appears in calculations of the individual band, but the total transmission and the total dissociation coefficients integrated over the entire SR (solar radiation) band region agree well between the methods. The ambiguities in the solar flux data affect the calculated dissociation coefficients more strongly than does the method. A simpler method is developed for the purpose of reducing the computation time and computer memory size necessary for storing coefficients of the equations. The new method can reduce the computation time by a factor of more than 3 and the memory size by a factor of more than 50 compared with the Hudson-Mahle method, and yet the result agrees within 10 percent (in most cases much less) with the original Hudson-Mahle results, except for H2O and CO2. A revised method is necessary for these two molecules, whose absorption cross sections change very rapidly over the SR band spectral range

CeMnNi4: an impostor half-metal

Recent experiments show CeMnNi$_{4}$ to have a nearly integer magnetic moment and a relatively large transport spin polarization, as probed by Andreev reflection, suggesting that the material is a half metal or close to it. However, the calculations reported here show that it is not a half metal at all, but rather a semimetal of an unusual nature. Phonon properties should also be quite unusual, with rattling low-frequency Mn modes. Nontrivial transport properties, including a large thermolectric figure of merit, $ZT,$ are predicted in the ferromagnetic state of the well ordered stoichiometric CeMnNi$_{4}$Comment: 4 pages, 6 fig

Structural analysis of hollow blades: Torsional stress analysis of hollow fan blades for aircraft jet engines

A torsional stress analysis of hollow fans blades by the finite element method is presented. The fans are considered to be double circular arc blades, hollowed 30 percent, and twisted by a component of the centrifugal force by the rated revolution. The effects of blade hollowing on strength and rigidity are discussed. The effects of reinforcing webs, placed in the hollowed section in varying numbers and locations, on torsional rigidity and the convergence of stresses, are reported. A forecast of the 30 percent hollowing against torsional loadings is discussed

A transceiver module of the Mu radar

The transceiver (TR) module of a middle and upper atmospheric radar is described. The TR module used in the radar is mainly composed of two units: a mixer (MIX unit) and a power amplifier (PA unit). The former generates the RF wave for transmission and converts the received echo to the IF signal. A 41.5-MHz local signal fed to mixers passes through a digitally controlled 8-bit phase shifter which can change its value up to 1,000 times in a second, so that the MU radar has the ability to steer its antenna direction quickly and flexibly. The MIX unit also contains a buffer amplifier and a gate for the transmitting signal and preamplifier for the received one whose noise figure is less than 5 dB. The PA unit amplifies the RF signal supplied from the MIX unit up to 63.7 dBm (2350 W), and feeds it to the crossed Yagi antenna

Supporting New Teachers of Color and Cultural Diversity

Educators and policy makers are calling for increasing the racial and cultural diversity of the teacher workforce, given the widening cultural gap between students and teachers (see Figure 1), and the widening achievement gap between students of color and White students. Some research suggests teachers of color can address the needs of students of color through culturally relevant practices (Quiocho & Rios, 2000). However, recent studies reveal teachers of color suffer greater job dissatisfaction and higher turnover than White teachers (Ingersoll & Connor, 2008; Marvel et al., 2007).Furthermore, cultural practices of teachers of color, if valued in our schools, need to be developed rather than assumed (Sheets, 2000). Given these circumstances, educators are faced with the following questions:- What factors impact retention and attrition of new teachers of color?- What factors support new teachers of color to develop and implement practices that address the needs of students from culturally and linguistically diverse backgrounds?These questions are addressed by a team of researchers at the New Teacher Center, UCSC in a study that followed 21 teachers of color over five years, from preparation through four years of teaching in high-need California schools serving low-income and high-minority student populations

Description of two new actinosporean types from a brook of Fuji Mountain, Honshu, and from Chitose River, Hokkaido, Japan

Actinospore infection of oligochaetes living in the mud of 3 freshwater biotopes in Japan was studied. Using the cell-well plate method, a new aurantiactinomyxon type was found in 0.77 % of the examined Tubifex tubifex oligochaete specimens from a brook near Yamanashi Prefectural Fisheries Experimental Station on Fuji Mountain. In 0.14 % of Lumbriculus variagetus collected from Chitose River, near Chitose Salmon Hatchery, a new siedleckiella type was found, while at the same time 8.1 % of the Lumbriculus spp. oligochaetes released triactinomyxons of Myxobolus arcticus. Of the examined Rhyacodrilus komarovi oligochaetes collected from the Mena River system, Hokkaido, 0.2, 0.6, 0.5 and 0.8% were infected with echinactinomyxon, neoactinomyxum and 2 types of triactinomyxon spores, respectively, and described in our previous paper. The oligochaetes released actinospores for several weeks. Actinospore infection showed high intensity in positive oligochaetes in the case of all the actinosporean types. Two of the actinospore types (aurantiactinomyxon and siedleckiella) presented here have not been previously described