Design of a Capacitorless Dynamic Random Access Memory Based on Ultra-Thin Polycrystalline Silicon Junctionless Field-Effect Transistor with Dual-Gate

In this paper, a 1T-DRAM based on the junctionless field-effect transistor (JLFET) with an ultrathin polycrystalline silicon layer was designed and investigated by using technology computer-aided design simulation (TCAD). The application of a negative voltage at the control gate results in the generation of holes in the storage region by the band-to-band tunneling (BTBT) effect. Memory characteristics such as sensing margin and retention time are affected by the doping concentration of the storage region, bias condition of the program, and length of the intrinsic region. In addition, the gate acts as a switch that controls the transfer characteristics while the control gate plays a role in retaining holes in the hold state. The device was optimized, considering various parameters such as the doping concentration of the storage region (Nstorage), intrinsic region length (Lint), and operation bias conditions to obtain a high sensing margin of 49.7 μA/μm and a long retention time of 2 s even at a high temperature of 358 K. The obtained retention time is almost 30 times longer than that predicted for modern DRAM cells by the International technology roadmap for semiconductors (ITRS).

Petrology of the April 2015 Eruption of Calbuco Volcano, Southern Chile

Understanding the origin of intermediate magmas that commonly erupt from subduction zone volcanoes is important to better constraining the mechanisms of continental crust formation. We performed a detailed mineralogical and petrological study of the eruptive products from the April 2015 eruption of Calbuco volcano, Chile, a three-phase sub-Plinian eruption that produced pyroclastic deposits of andesitic composition. The eruptive products comprise a glass phase and a high but variable proportion of minerals dominated by plagioclase, clinopyroxene, and orthopyroxene, with minor olivine, amphibole, and magnetite. Plagioclase is very strongly zoned with highly anorthitic cores surrounded by more albitic rims, and no intermediate compositions between them. Based on thermodynamic calculations and published experimental data, we estimate that the anorthitic cores crystallized from a basaltic andesite melt containing 3·5–4·5 wt% H2O. The bulk-rock major and trace element variability at Calbuco is best explained by the accumulation of a variable amount of minerals (in relative proportion 72 % plagioclase, 28 % pyroxene) in a dacitic melt. These minerals most probably formed in the crystal mush zone of the magma chamber, at 200–300 MPa (8–11 km depth) according to pyroxene and amphibole compositions. A few weeks to months before the eruption, the crystal mush was disaggregated, perhaps owing to magmatic underplating, and a crystal-bearing dacitic melt migrated into a subsurface storage region where the albitic plagioclase rims crystallized. The eruption was probably internally triggered by over-pressurization in the shallow magma chamber.

Petrology of the April 2015 eruption of Calbuco volcano, southern Chile

<p>Understanding the origin of intermediate magmas that commonly erupt from subduction zone volcanoes is important to better constrain the mechanisms of continental crust formation. We carried out a detailed mineralogical and petrological study of the eruptive products from the last eruption of Calbuco volcano, Chile. In April 2015, Calbuco produced a 3 phase sub-Plinian eruption with pyroclastic fallouts and flows of andesitic composition. Rocks from Calbuco are made up of a glass phase and a high but variable proportion of minerals dominated by plagioclase, clinopyroxene, orthopyroxene and minor olivine, amphibole and magnetite. Plagioclase is very strongly zoned with highly anorthitic cores surrounded by more albitic rims. Based on thermodynamic calculations and using published experimental data, we estimate that the anorthitic cores crystallized from a basaltic andesite containing 3.5-4.5 wt.% H<sub>2</sub>O. Using geochemical modelling, we also estimate that the bulk-rock major and trace element variability of Calbuco is best explained by accumulation of minerals in proportion plagioclase/pyroxene 72/28 in a dacitic melt. Such minerals most likely formed in the crystal mush zone of a magma chamber which, according to pyroxene and amphibole compositions, may have formed at a pressure of 2-3 kbar, corresponding to a depth of 8-11 km. A few weeks to months before the eruption, the crystal mush disaggregated, perhaps due to magmatic underplating, and a crystal-bearing dacitic melt moved upwards into a sub-surface storage region where the anorthite-poor rims formed. The 2015 eruption was probably internally triggered by over-pressurization in the shallow magma chamber.</p>

Reduced levels of stromal sex hormone-binding globulin and androgen receptor dysfunction in the sperm storage region of the rat epididymis

The cauda epididymidis is the major sperm storage region whose androgenic supply, essential for the sperm viability, is provided by the vasculature and is dependent upon testosterone diffusion through the stromal tissue to reach the epithelial cells. We have focused our efforts on examining the regulation of this important epididymal region by evaluating the impact of the androgen disrupter cimetidine on the epithelial–stromal androgenic microenvironment. Male rats received 100 mg/kg cimetidine (CMTG) or saline (CG) for 50 days, serum testosterone levels were measured and the epididymal cauda region was processed for light and transmission electron microscopy. In the proximal cauda region, the duct diameter was measured and birefringent collagen in the stroma was quantified. TUNEL-labeled epithelial cells were quantified, and androgen receptor (AR), karyopherin alpha (KPNA) and sex hormone-binding globulin (SHBG) levels were analyzed by immunofluorescence and Western blot. CMTG showed reduced duct diameter and high number of apoptotic epithelial cells. In the epithelium, the total AR concentration and the KPNA immunoreactivity were reduced, and a weak/absent AR nuclear immunofluorescence was observed in contrast to the enhanced AR immunolabeling observed in the cytoplasm of the epithelial cells. A significant reduction of collagen and SHBG levels in the stroma was also observed. Cimetidine treatment impairs AR nuclear import in the epithelium, causing androgenic dysfunction and subsequent epithelial cell apoptosis and duct atrophy. The connective tissue atrophy and reduction of SHBG stromal levels associated with epithelial androgenic dysfunction indicate a possible role of stromal SHBG in the androgenic supply of the sperm storage region of the epididymis.