Measurements of N2O and NO emissions during tomato cultivation using a flow-through chamber system in a glasshouse

Nitrous oxide (N₂O) and nitric oxide (NO) fluxes resulting from long-term tomato cultivation in a glasshouse were continuously determined using the flow-through chamber method over the course of three cultivation periods. Gas concentrations were measured using an nondispersive infrared (gas filter correlation/infra-red) analyzer and a chemiluminescence-based analyzer, respectively. Following a basal application of fertilizer, daily N₂O and NO emission rates increased, with peaks lasting from 40 to 140 days. Short-term fluctuations in daily N₂O and NO emissions were affected by differences in nitrogen application, soil water, and soil temperature. Diurnal changes in N₂O and NO fluxes during the period of peak emissions depended primarily on soil temperature. Following the application of a top dressing (N as urea or calcium nitrate) in the irrigation water, the N₂O and NO fluxes increased immediately, with a very short period of peak emissions (1–5 h) after urea application. The duration of the peak period in daily accumulated N₂O and NO emissions following application of the top dressing ranged from 3 to 10 days.     

Decomposition of water by a CaTiO3 photocatalyst under UV light irradiation

Platinized CaTiO₃ powder (band gap 3.5 eV) had a high photocatalytic activity of decomposing water into H₂ and O₂ under the irradiation of UV light, especially with photon energies above 3.8 eV. The existence of this photocatalytic activity is further supported on electrochemical grounds in that the photoinduced current spectrum measured between a CaTiO₃ single crystal and a Pt electrode without applied voltage in water showed a maximum near 4.1 eV. This result indicates that the direct measurement of the spectrum corresponding to the efficiency of water decomposition is an effective method to survey photocatalytic activities of materials.     

Distribution of a Life Ratio and Its Application

This paper consists of two parts, both of which are concerned with a ratio of two lives from life test data. Part 1 derives an exact distribution of the quotient of two random variables, each of which follows the truncated extreme-value distribution. Then graph of the cumulative distribution function is given for several values of a parameter. Part 2 develops a control chart for sample ratios to be used in controlling the deterioration of quality characteristics having an extreme-value distribution.     

Degradation of phenolic compounds in water by non-thermal plasma treatment

A stainless-steel hollow needle type anode was used in the reactor to treat industrial wastewater by gas-liquid phase of non-thermal plasma by corona discharge. The results showed that the short electrode gap, 1 cm, has a higher plasma energy density which improves the removal of the phenolic derivatives, reaching 100% after about 60 min. The H₂O₂ concentration was higher in the discharge system when the content of oxygen was increased. The efficiency of the phenol removal by chemical oxygen demand was only 10?C31% after 60 minutes. The identified intermediates were catechol, hydroquinone, 1,4-benzoquinone, 2-nitrophenol, 1,2-benzenedicarboxylic acid, diphenylmethanone, 2-methyl-hydroquinone, 2-methyl-1,4-bezoquinone, and trace amounts of organic.     

Functioning of traditional ceramics 12CaO·7Al2O3 utilizing built-in nano-porous structure

This paper briefly reviews our approach to render active functions to micro porous crystal 12CaO·7Al₂O₃ (C12A7), which is known as a constituent of alumina cement, utilizing nano-space and topology of sub-nanometer-sized cages inherent to the crystal structure. Each cage with a positive charge is coordinated by 12 cages to form a three-dimensional structure. This structure is a similar to a close packing of sphere except that each opening wall of a cage is shared with a neighboring cage. Free oxygen ion O^2– accommodates in 1/6 of the cages to reserve electro neutrality in the stoichiometric state. We replaced this free oxygen ion by other active anions such as O^–,H^–, and electron, aiming at emergence of novel function. C12A7:O^– exhibited strong oxidation power enough to oxide Pt, and field-assisted thermionic O^– emission to several μA levels, while conversion of insulator to persistent electronic conductor by illumination with ultraviolet radiation was discovered in C12A7:H^– sample. Further, almost all of the free O^2– ions in the cages were successfully replaced by electrons by a chemical treatment using metallic Ca. The resulting material, which has a composition [Ca₂₄Al₂₈O₆₄]⁴⁺(4e^–) and a high conductivity, ～ 100 S cm^–1 at 300 K, is a first room-temperature stable electride, in which electrons work as anions. The present approach to novel function emergence by solely employing abundant oxide materials and fully utilizing nanostructure provides a way for material research for future to be done under severe circumstance of environment and resource.     

Synthesis and Applications of SnO Nanosheets: Parallel Control of Oxidation State and Nanostructure Through an Aqueous Solution Route

Tin monoxide (SnO) nanosheets 5 nm in thickness are generated on substrates through an aqueous solution process under mild conditions. Parallel control of the oxidation state and morphology is achieved by a urea‐mediated approach in aqueous solution. The SnO nanosheets form a porous thin film on substrates such as indium tin oxide and carbon nanofiber (CNF). The porous thin film of SnO nanosheets shows cathodic photocurrent generation upon irradiation by UV and visible light. In contrast, the photocurrent is not observed in the bulk SnO microcrystals. Composites of the SnO nanosheets and CNF perform as the anode material of lithium‐ion batteries with improved charge–discharge reversible stability.     

Amorphous In-Ga-Zn-O thin-film transistor with coplanar homojunction structure

Amorphous In-Ga-Zn-O (a-IGZO) thin-film transistors (TFTs) with a coplanar homojunction structure are demonstrated. The coplanar source and drain regions made of a-IGZO were formed by depositing a hydrogenated silicon nitride (SiN_X:H) layer onto the a-IGZO layer. The a-IGZO regions on which the SiN_X:H layer was directly deposited showed the low resistivity of 4.7 × 10⁻³  Ω cm and degenerated conduction. The fabricated TFT showed excellent transfer and output characteristics with a field-effect mobility of 11 cm² V^− 1 s^− 1, a subthreshold swing of 0.17 V decade^− 1, and an on-to-off current ratio larger than 1 × 10⁹. The width-normalized source-to-drain resistance (R_sdW) calculated using a channel resistance method was 51 Ω cm. This TFT also showed good stability over environment change and under electrical stress.     

A 130-mm2, 256-Mbit NAND flash with shallow trenchisolation technology

A 256-Mbit flash memory has been developed using a NAND cell structure with a shallow trench isolation (STI) process. A tight bit-line pitch of 0.55 μm is achieved with 0.25-μm STI. The memory cell is shrunk to 0.29 μm², which realizes a 130-mm² , 256-Mbit flash memory. Peripheral transistors are scaled with memory cells in order to reduce fabrication process steps. A voltage down converter, which generates 2.5-V constant internal power source, is applied to protect the scaled transistors. An improved bit-line clamp sensing scheme achieves 3.8-μs first access time in spite of long and tight pitch bit-line. A 1-kbyte page mode with 35-ns serial data out realizes 25-Mbyte/s read throughput. An incremental step pulse with a bit by bit verify scheme programs 1-k cells in 1-V Vt distribution within 200 μs. That realizes 4.4-Mbyte/s programming throughput