Electromagnetic beam wave scattering by arbitrary cross-sectional conducting cylinder using N circular cylindrical models

Rigorous expression of the electromagnetic beam wave scattering by N circular cylindrical models is described. To check this method, comparison between exact solution and this model composed of N=24 circular cylinders is presented for a single circular conducting cylinder. Numerical results of conducting square cylinder has been also checked with well-known result (B.E.M).     

Ferromagnetism and anomalous transport in GaAs doped by implantation of Mn and Mg ions

GaAs layers doped by implantation of Mn and Mg ions to increase the hole concentration were synthesized and studied. Measurements using a SQUID magnetometer showed that there is ferromagnetism at temperatures as high as 400 K, which is related to the formation of the MnAs and Mn _y Ga_{1 ? y} clusters as a result of high-temperature annealing, in addition to the formation of the Ga_{1 ? x} Mn _x As alloy. The anomalous Hall effect was observed at temperatures in the range from 4.2 to 200 K. As temperature was increased starting with 4.2 K, the negative magnetoresistance with extremely large magnitude transformed into a giant positive magnetoresistance at T ≈ 35 K.     

Influence of humidity and of the electric and magnetic microwave radiation fields on the remediation of TCE-contaminated natural sandy soils

The influence of moisture content (15% w/w) on the remediation (vaporization) of trichloroethylene (TCE) present in natural sands, chosen as a TCE-polluted model system for soils, was investigated with regard to applied microwave power levels, the depth of the sand sample, and the dielectric factors. The heating process occurring in the sand samples arises through the microwave conduction loss heating and dielectric loss heating mechanisms. The characteristic relevance of the electric and magnetic microwave radiation fields to the heating mechanisms was also examined. Heating by the magnetic microwave radiation field was considerable when magnetite was added to the dry and wet sand samples as the microwave absorber. Optimal microwave conditions are reported for a single-mode microwave applicator. Near-quantitative elimination of the TCE contaminant was achieved for sandy soils within a very short time.     

Objective determination of fatigue development following sun exposure using Advanced Trail Making Test

Sun exposure during leisure activity evokes fatigue. We employed the Advanced Trail Making Test (ATMT), a recently developed objective method of evaluating brain function performance used to measure mental fatigue, for objective determination of fatigue development caused by solar exposure to the human body. First, a survey of consumer awareness was performed, and fatigue development from solar exposure was generally recognized in both summer and spring. In the field test, 15 males (26-41 years old) received sun exposure equivalent to 100 kJ m(-2) of ultraviolet radiation three to four times each day for 3 days, during which the subjects wore a short sleeve shirt and a short pant, and covered their head with a towel. A significant increase in scores for subjective sense of fatigue was observed in the evening of all 3 days following sun exposure and on the fourth day, which had no exposure, as well as in the morning of the third and fourth days, as compared with those periods during the control week, which did not have experimental solar exposure. ATMT showed a significant increase in average value in the evening of the first and second days following sun exposure, as well as in the morning of the third and fourth days. In addition, increases in body temperature and heart rate were observed during the exposure periods. The results of multiple regression analysis of subjective feelings showed that fatigue caused by solar exposure was qualitatively different from that in the control week. These results suggest that brain function performance declined following solar exposure as did fatigue development. ATMT results may be useful for quantitative and objective evaluation of mental fatigue caused by sun exposure, along with development of sun care products for the prevention of solar-caused fatigue.     

Multiplex PCR for simultaneous detection of Salmonella spp., Listeria monocytogenes, and Escherichia coli O157:H7 in meat samples

A multiplex PCR method was developed for simultaneous detection of Salmonella spp., Listeria monocytogenes, and Escherichia coli O157:H7 in meat samples. DNA detection sensitivity for this method was 10(3) CFU/ml for each pathogen. When this protocol was used for the detection of each of the above pathogenic bacteria in spiked pork samples, 1 cell per 25 g of inoculated sample could be detected within 30 h. In the samples of naturally contaminated meat, Salmonella spp., L. monocytogenes, and E. coli O157:H7 were detected over the same time period. Excellent agreement was obtained for the results of multiplex PCR and the conventional culture method, which suggests that the multiplex PCR is a reliable and useful method for rapid screening of meat products for Salmonella spp., L. monocytogenes, and E. coli O157:H7 contamination.     

Protoplast Transformation of Alkalophilic Bacillus sp. by Plasmid DNA

A method for transformation of alkalophilic Bacillus sp. A-59 (ATCC21591, alkaline amylase producing bacterium) with plasmid DNA was developed. Plasmid pHWl containing a chloramphenicol acetyltransferase gene was used as a vector, because chloramphenicol was the only antibiotic found to be stable at alkaline pH condition. Transformation was carried out by a protoplast method and addition of polyethylene glycol (PEG; final concentration 22.5%) was essential for transformation. Optimum pH values of the media and buffers were slightly higher than those used in transformation of Bacillus subtilis protoplasts. Through optimization of transformation conditions for alkalophilic Bacillus sp., the transformation efficiency was increased to approximately 10⁶ transformants per μg plasmid DNA.     

Kinetic Characterization of Chimeric Cyclomaltodextrin Glucanotransferase from Genes of Two Alkalophilic Bacillus

The chimeric CGTase, which was constructed genetically with two β-CD forming type enzyme genes of different species of alkalophilic Bacillus, was characterized by comparing with the actions of parent enzymes. The final composition of CDs in the reaction digest from starch by the chimeric enzyme, especially in the yield of α-CD, was different from those by parent enzymes, and total yields of CDs by these enzymes were almost the same. The chimeric enzyme catalyzed the formation of β-CD as a major action from starch, the rapid synthesis of α-CD from other CDs and maltooligosaccharides and the slow degradation and interconversion of α-CD to others. From these results, the role of second and third segments in the enzyme molecules was discussed.     

Isolation and Partial Properties of Cyclomaltodextrin Glucanotransferase-producing Alkaliphilic Bacillus spp. from a Deep-sea Mud Sample

Cyclomaltodextrin glucanotranferase (CGTase) producing alkaliphilic bacteria were isolated from deep-sea bottom mud samples. Isolates no. 3–22 and no. 1–7 were identified as an alkaliphilic Bacillus sp. and an alkaliphilic Bacillus subtilis strain from their taxonomic characteristics, respectively. Isolate no. 3–22 grew at 4°C whereas isolate no. 1–7 did not. The crude enzymes of both strains showed activity in both broad temperature and broad pH (5–9) ranges, Isolate no. 3–22 produced the main product. β-cyclodextrin (β-CD), and minor products, α- and γ-CDs from starch. On the other hand, isolate no. 1–7 produced the main product, β-CD, and the minor product, γ-CD from starch; no α-CD was detected.     

Production of Trehalose from Starch by Maltose Phosphorylase and Trehalose Phosphorylase from a Strain of Plesiomonas

The cooperative concomitant action of maltose phosphorylase (MP), trehalose phosphorylase (TP), β-amylase and a starch debranching enzyme (pullulanase, isoamylase) was investigated to develop a more efficient method for preparing trehalose from starch. About 40 and 51—56% as solid basis of 25% (w/v) liquefied potato starch were converted to trehalose by the combination of soybean β-amylase and the crude enzyme preparation (MTA) containing MP, TP and a saccharogenic amylase from a strain (SH-35) of Plesiomonas in the absence and presence of a starch debranching enzyme, respectively. A stable maltose syrup (70%, w/w) containing about 30% trehalose in the dry solid was prepared from starch directly, and about 36% as dry basis of the mother liquor (70%, w/w) containing about 56% trehalose was obtained as crystals of this non-reducing disaccharide by conventional crystallization. Trehalose in the by-product obtained after removing crystals increased up to almost that of the mother liquor by reacting with MTA again. By the method reported here, trehalose was produced from starch on an industrial scale without any remaining by-products.