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There is concern over the environmental impact of charcoal use for cooking in urban areas; however, studies have mainly been limited to Africa and South Asia. This investigation aimed to evaluate woodfuel consumption rates and patterns in an urban area in Yedashe Township, Myanmar and compared them with results from a rural area in the same township. From interviews with 66 urban households, it was evident that firewood and charcoal consumption rates in the urban area were about one-third and one-fourth, respectively, of those in the rural area. These low consumption rates were because of multiple-fuel use (mainly woodfuel and electricity) in the urban area in contrast to single-fuel use in the rural area. We estimated the forest area required to meet woodfuel demand of the whole township to be 3738 ha; that could decrease by almost 40% (1592 ha) if the single-fuel use in the rural area switched to the multiple-fuel methods used in the urban area. This study confirms that urbanization with an “energy stack” in multiple-fuel use, rather than an “energy ladder” from firewood to charcoal, could largely reduce the environmental impact on forests.

Summary In this study, foaming of heavy oil generated by depressurization from saturated carbon dioxide (CO2) solution was studied because generating foamy oil has a possibility of developing an enhanced oil recovery (EOR). The experiments were carried out by with a heavy crude oil at CO2 pressure less than 10 MPa and a temperature from 20 to 50 °C. The swellings of the generated foamy oils increased from 36.8 to 47.5% with reducing viscosity ratio from 79 to 42%, comparing with original viscosity. Furthermore, the investigation shows that CO2 microbubbles in the foamy oil started nucleating at pressure less than 8.0 MPa during depressurization from the saturation pressure of 9.97 MPa at 50 °C, and the foamy oil started decreasing the apparent viscosity. By exposing generated foamy oil under the shear rate of 76.8 seconds−1 for 5 minutes, the bubble-volume density profile changes from broadband toward to Gaussian distribution caused by disappearing larger size of gas bubbles, where bubble diameter of the maximum probability density of the bubble-volume distribution reduced from 80 μm to less than 10 μm. However, reduction of viscosity ratio was almost kept even though the distribution was changed; this shows that apparent viscosity strongly depends on the microbubbles sized less than 10 μm in diameter. It was expected that CO2 foamy oil has a potential to improve the recovery ratio of heavy oil by making the residual oil flow out from the immobile zones because of its large apparent swelling and improving mobility in porous oil-flow.

The world’s two largest economies, the United States and China, have fundamentally different cultural beliefs about learning. Thus, when examining Chinese learners, Western researchers were confused by the contrasting phenomenon between seemingly poor learning approaches and high academic achievement, i.e., the Paradox of Chinese Learners. In addressing this paradox, Jin Li offered a theoretical framework of the Chinese virtue model versus the European–American mind model to comprehensively understand the differences in students’ learning beliefs and academic achievement between the two cultures. However, Li does not pay attention to global cultural exchange or directly link learning beliefs to academic achievement. Therefore, this paper presents two empirical studies addressing these research gaps. Study 1 adopted both qualitative and quantitative methods to investigate the learning beliefs of Chinese and European–American university students, and revealed that deepening cultural exchange narrowed the gap between the two models (Study 1a), but the impact of the virtue model on European–American students was weaker than that of the mind model on Chinese students (Study 1b). Study 2 further revealed that both models were beneficial for Chinese students’ academic achievement, whereas only the virtue model benefited European–American students. These findings have important implications for addressing the Paradox of Chinese Learners.

Abstract The yields and energy spectra of primary neutrons emitted from spent molten-salt fuel have been analyzed as a function of cooling time. It was found that (α, n) reactions made a major contribution to neutron production in the Th-based molten-salt fuel, in contrast to the case of U-fuels for LWRs where spontaneous fission was a main contributor. One of the consequences of this was that the neutron yield continued to increase to reach a maximum 8–9 yr after irradiation, reflecting variation of the concentrations of strong α-emitters in the Th series. This peculiar characteristic requires that attention should be paid to neutron- as well as γ-shielding of storage facilities of spent molten-salt fuel.

Abstract Understanding evolution of the functionalities of biochar versus temperature is a prerequisite for exploring application of biochar as functional carbon materials. In this study, pyrolysis of lignin with different heating rates was conducted. The results indicated that the higher heating rate promoted formation of more gases via the accelerated cracking of both the organic components of biochar and the volatile products. In addition, the deoxygenation reactions were suppressed at higher heating rate with short residence time, leading to the biochar with lower heating value and energy yield. The in situ Diffuse Reflection Infrared Fourier Transform Spectra (DRIFTS) characterization of the lignin pyrolysis indicated monotonous increase of the abundance of =C−H, C=C and C−O−C functionalities versus increasing pyrolysis temperature. However, the −OH, −CH3 and C−H2 in alkanes and the C=O were not thermally stable. Abundance of −OH maintained a plateau in 200−450 °C, while that for −CH3 and C−H2 in alkanes also reached maximum at ca. 450 °C and the further increasing heating temperature led to significant decomposition. The decomposition of C=O started at the lower temperatures of 200–325 °C, and the lactones, unconjugated alkyl aldehydes, alkyl esters, conjugated aldehydes/ketones experienced distinct temperature-abundance histories.

This paper proposed and validated a new coal devolatilization model that can predict yields of respective gas and tar components, and be directly coupled with an elementary step-like reaction model. The new model was an extension of the chemical percolation devolatilization (CPD) model. The CPD model is one of the existing primary pyrolysis models that consider the coal chemical structure. The mole fraction of labile bridges, cross links, peripheral groups, and average molecular weight of monomer in coals examined in this study were determined by a 13C NMR analysis. The aromatic ring clusters size distribution was determined by a coal pyrolysis test using a Curie point pyrolyzer. The thermal decomposition process of the coal chemical structure was expressed by nine elementary reactions. From the above, the extended CPD model can predict gas and tar components as respective chemical species (H2O, CO2, CO, CH4, benzene, naphthalene and phenanthrene) and consequently capture the secondary decomposition and polymerization in gas phase by coupling the detailed gas-phase chemistry. The proposed model was validated by comparing with experiments using a pressurized drop tube furnace (PDTF). The results showed that the trend of light gases and soot yield in the experiments could be successfully reproduced by the extended CPD model.

金網の最大毛細管圧力は, 金網ウイックを持つヒートパイプの最大熱輸送量を評価するための, 最も重要な因子の一つである.本研究では, 平織り金網について, メニスカス断面形状が円であると仮定して, 金網の幾何学的形状および隣接格子に形成されるメニスカスがメニスカス破壊に及ぼす影響を考慮して, 最大毛細管圧力に関する解析を行った. また, 最大毛細管圧力を実験的に求め, 接触角の違いがメニスカス形状に及ぼす影響を明かにし, 実験値と解析解との対応を整理することによって, 平織り金網の最大毛細管圧力を表す半経験式を導出した.その結果, 最大毛細管圧力は接触角の増大とともに減少するが, 接触角が (π/2) radの場合でも大きい毛細管圧力を発生し得ることを示した.