All issues
Volume 31 (2000 - 200･･･
- Issue 4 Pages 197-
- Issue 3 Pages 145-
- Issue 2 Pages 79-
- Issue 1 Pages 1-
Volume 31, Issue 4
Displaying 1-4 of 4 articles from this issue
- |<
- <
- 1
- >
- >|
-
Jong-Soo PARK, Kohta ISHII, Hideo TERAO2001 Volume 31 Issue 4 Pages 197-204
Published: March 25, 2001
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSThe purpose of the study is to investigate fundamental characteristics of the system operation and an energy efficiency on a dual-fueled cogeneration system (CGS) of biogas and gas oil. Experiments of the CGS were conducted by varying biogas flow rates, engine loads, and engine speeds.
As a result of the experiment, data for the system simulation that aims to analyze the heat balance and the system efficiency were obtained. In the CGS, supplying biogas to the engine caused to reduce smoke and NOx emissions in an exhaust gas. A heat recovery ratio of the developed CGS indicated from 35 to 50%, and the total energy efficiency reached from 50 to 80%. To improve further more the efficiency of the dual-fueled CGS, it was suggested that scheduling biogas flow rates, engine loads, and engine speeds were required.View full abstractDownload PDF (2257K) -
Shuyun ZHAO, Zhenya ZHANG, Chris P. NORMAN, Takaaki MAEKAWA2001 Volume 31 Issue 4 Pages 205-213
Published: March 25, 2001
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSTwo experiments were designed to test the effects of 6 trace metal compounds on the hydrogen production and growth of Enterobacter aerogenes. The first experiment examined the effects of the addition of a single trace metal and in the second experiment the effects of the omission of one trace metal from media containing combinations of the other five trace metals were examined. Hydrogen production was improved and reduced compared to the control by the addition of CoCl2 and CuSO4, respectively, while in the second experiment the omission of these two metals led to no apparent changes. Further, hydrogen production rates were improved by adding MnCl2, FeCl2. For the other two trace metal compounds, the addition of H3BO3 and NaWO4 inhibited the hydrogen production completely in the first experiment, while dual roles were observed in the second experiment. Compared to the control run, the maximum hydrogen production rates was increased by about 20% or decreased by about 40% in experiment 1 by the stimulatory or inhibitory effects of the trace metals, while it was increased by 40% or decreased by 12% in experiment 2. Further, the effects on pH and cell density during the hydrogen evolution by the trace metals were observed. Both the pH and cell density were basically consistent with that of the hydrogen evolution rate in the culture medium.View full abstractDownload PDF (2250K) -
Ikko IHARA, Takaaki MAEKAWA2001 Volume 31 Issue 4 Pages 215-224
Published: March 25, 2001
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSThe stability of the methane fermentation process is highly dependent on the activity of methanogens. On-line monitoring of appropriate parameters is required in order to avoid process failure. NAD(P)H fluorescence is to detect the microbial metabolic state changes and a commercially probe designed to detect NAD(P)H has been developed. The use of NAD(P)H fluorescence probe to monitor the anaerobic digestion was evaluated. A laboratory scale anaerobic reactor was operated on synthetic medium with a substrate containing of either acetic acid or glucose at mesophilic temperature for the hydraulic retention time of 10-5 days. During start up, NAD(P)H fluorescence were highly unbalanced. After 32 days steady state was reached with a stable methane production. The response of NAD(P)H fluorescence were low and stable. Once the reactor was overloaded, an increase in acetate concentration and a decrease in methane production rate were observed. Acetic acid constituted the main part of the VFA concentration inhibited the growth of methanogens. After that the time lag NAD(P)H increased slowly. The result showed that these changes were related to the metabolic state in the reactor. It was suggested that NAD(P)H could be utilized for on-line monitoring of anaerobic digestion.View full abstractDownload PDF (1120K) -
Tomoyuki YOSHINO, Seiichiro ISOBE, Takaaki MAEKAWA2001 Volume 31 Issue 4 Pages 225-231
Published: March 25, 2001
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSα-zein is a hydrophobic protein of corn. The zein films were cast from an organic solution (70% aqueous acetone or 80% aqueous ethylalcohol) containing zein. Biodegradable zein films without plasticizer were made using various controlled drying conditions during preparation. The zein films were transparent. Oxygen (O2) and carbon dioxide (CO2) permeability of the zein films were measured. The lowest and highest O2 permeability of the zein film was 6.5pmol·m/(s·m2kPa) of the zein ethanol film and 303.3pmol·m/(s·m2kPa) of zein acetone film, respectively. On the other hand, the lowest and highest CO2 permeability of the zein film was 1.0pmol·m/(s·m2kPa) of the zein ethanol film and 1541.0pmol·m/(s·m2kPa) of zein acetone film, respectively. Some zein films have a higher O2 permeability than CO2 permeability. For example, O2 and CO2 permeability of the zein acetone films was 303.3 and 30.6pmol·m/(s·m2kPa), respectively. The ratio of O2 permeability to COT permeability of the 10% zein acetone films increased with increasing relative humidity during drying. The selective gas permeability of the zein films was kept between 5°C and 35°C. By finding relationships between the mechanism of gas permeability and the drying conditions, the film may be formed with advantageous gas permeability properties. We expect that it will be possible to make zein film with various useful gas permeability properties by using controlled drying conditions. The zein films with the selective gas permeability appear to be useful for the agricultural film such as a green house and a mulching.View full abstractDownload PDF (890K)
- |<
- <
- 1
- >
- >|