Upgrading and dewatering of raw tropical peat by hydrothermal treatment

In this study, hydrothermal upgrading and dewatering of raw tropical peat derived from Pontianak, West Kalimantan-Indonesia was evaluated at temperatures ranging from 150 to 380 °C, a maximum final pressure of 25.1 MPa and a residence time of 30 min. The moisture content of the raw peat was approximately 90 wt.%. Raw peat was hydrothermally upgraded without the addition of water in the laboratory scale. The yield of the solid products was between 53.0 and 99.7 wt.% and the effective calorific value of hydrothermally dewatered peat was between 17,290 and 29,209 kJ/kg following hydrothermal upgrading. In addition, the oxygen content in the solid product was varied from 38.4 to 15.6 wt.% after upgrading, while the carbon content from 55.2 to 77.8 wt.%. The hydrothermally upgraded peat fuel product also had an equilibrium moisture content of 2.3 wt.% and a maximum equilibrium moisture content of 17.6 wt.%. Upgraded peat is characteristically resistant to moisture adsorption at high humidity, which makes it promising for fuel based combustion. The change in the carbon-functional groups and their properties, as determined by FTIR and ¹³C NMR, are discussed in terms of the hydrothermal upgrading and dewatering process.     

X-ray photoemission spectroscopy of nitrogen-doped UNCD/a-C:H films prepared by pulsed laser deposition

Nitrogen-doped ultrananocrystalline diamond (UNCD)/hydrogenated amorphous carbon (a-C:H) films were deposited by pulsed laser deposition (PLD). Nitrogen contents in the films were controlled by varying a ratio in the inflow amount between nitrogen and hydrogen gases. The film doped with a nitrogen content of 7.9 at.% possessed n-type conduction with an electrical conductivity of 18 Ω^? 1 cm^? 1 at 300 K. X-ray photoemission spectra, which were measured using synchrotron radiation, were decomposed into four component spectra due to sp², sp³ hybridized carbons, C=N and C–N. A full-width at half-maximum of the sp³ peak was 0.91 eV. This small value is specific to UNCD/a-C:H films. The sp²/(sp³ + sp²) value was enhanced from 32 to 40% with an increase in the nitrogen content from 0 to 7.9 at.%. This increment probably originates from the nitrogen incorporation into an a-C:H matrix and grain boundaries of UNCD crystallites. Since an electrical conductivity of a-C:H does not dramatically enhance for this doping amount according to previous reports, we believe that the electrical conductivity enhancement is predominantly due to the nitrogen incorporation into grain boundaries.     

Effect of aromatic nitroso-compounds on superoxide-generating activity in neutrophils

Aromatic nitroso-compounds such as nitrosobenzene inhibited the respiratory burst of intact neutrophils induced by various stimulants, including phorbol 12-myristate 13-acetate and a chemotactic peptide. The compounds also inhibited NADPH-dependent oxygen consumption by cell-free preparations of neutrophils. This indicates that nitroso-compounds act directly on the NADPH-oxidase system. The inhibitory effects induced by several nitroso-compounds, 2-nitrosotoluene, nitrosobenzene, 4-nitrosophenol, and 1-nitrosopyrrolidine, were examined and their inhibition constants, the concentrations causing 50% reduction of oxygen consumption, were found to be 0.043, 0.173, 0.672, and 32.1 mM, respectively. These values correlated well with the hydrophobicity of the compounds: a more hydrophobic compound was a more potent inhibitor against NADPH oxidase, suggesting that the oxidase has a hydrophobic site(s) for interaction with the inhibitors.     

A quasi-three-dimensional elastic wave propagation analysis for laminated composites

Localized impact problems for composite structures have recently become important. In this study, some elastic wave velocities in 7-ply GFRP laminate with [0₂/90₃/0₂] ply orientation after low speed impact was investigated by using both experimental methods and finite element methods. For the finite element simulation, the quasi-three-dimensional model was used. Comparing the results, the validity for the application of this model to the dynamic problem was estimated. Moreover the quasi-three-dimensional model is applied to the GFRP plates with interlaminar delamination. The relationship between the elastic wave velocities and delaminated states is discussed.     

A comparison of the hydrolysis of sweet potato starch with β-amylase and infrared radiation allows prediction of reducing sugar production

The apparent reaction rate constants (k) of the reaction that generates reducing sugar (presented as mg maltose equivalents) from raw sweet potato starch by using β‐amylase were determined by varying enzyme concentration, starch concentration and pH. The Arrhenius plot of the k‐value reached a peak at approximately 86 °C; the activation energy and frequency factor were also determined. Moreover, the amount of reducing sugar produced in sweet potato heated by infrared irradiation was estimated by using the values of k and the kinetic parameters. The calculated amounts of reducing sugar produced generally agreed with the experimental values. These results indicate that the amount of reducing sugar produced in heat‐treated sweet potato can be predicted by the methodology described in this study.     

Enzymatic hydrolysis of water-soluble random copolypeptides

Two component water-soluble random copolypeptides consisting of N-hydroxyethyl L-glutamine and hydrophobic L-amino acids such as L-alanine, L-leucine, L-phenylalanine, or L-valine, were prepared by carrying out aminolysis reactions with 2-amino-1-ethanol (E) on starting copolymers consisting of γ-benzyl L-glutamate (B) and the corresponding hydrophobic L-amino acid. The effects of copolymer composition and sequential distributions, as well as molecular conformations, on the rate of degradation by bromelain in a PECF at pH 7.4 and 37.0°C to simulate in vivo polymer degradation. All the samples were found to be extensively degraded by random chain fracture with bromelain. Further, the degradation data for these samples followed the Michaelis-Menten rate law, being of the first order in papain concentration. The nature of side chains and the molecular conformations are important to the rate of degradation by bromelain.     

Differences in the recognition of tumor-specific CD8+ T cells derived from solid tumor, metastatic lymph nodes and ascites in patients with gastric cancer

We established gastric cancer-specific CD8+ T-cell (T(CD8+)) lines derived from different lymphocyte sources in the same patients by repeated stimulation with mitomycin-C-treated autologous tumor cells with low-dose interleukin-2, and we compared recognition patterns among the T(CD8+) derived from solid tumor, lymph node metastasis and ascites in the same patient (n = 3) to determine their similarities and differences for therapeutic purposes. We confirmed that gastric cancer-specific T(CD8+) lines can be isolated, in a MHC class I-restricted manner, from solid tumors, metastatic lymph nodes and malignant ascites. T(CD8+) lines derived from tumor-infiltrating lymphocytes (TIL) in solid tumor recognized autologous tumor cells derived from solid tumor, but not autologous tumor cells derived from ascites or metastatic lymph node, while T(CD8+) lines derived from tumor-associated lymphocytes (TAL) in malignant ascites recognized autologous tumor cells derived from ascites, but not tumor cells from solid tumor or metastatic lymph node. Furthermore, T(CD8+) lines derived from regional lymph node lymphocytes (RLNL) recognized autologous tumor cells derived from metastatic lymph nodes, but not tumor cells derived from ascites. No significant differences were seen in MHC class I expression among the tumors derived from solid tumor, lymph node metastasis or ascites in the same patient. This suggests that there are differences of recognition patterns among the TILs, TALs and RLNLs in the same patient and that it is important to consider the source of lymphocytes, e.g., a combination of TILs, TALs and RLNLs, for adoptive immunotherapy in gastric cancer patients.