The possibility of attenuation of microseismic waves due to the presence of an upward folding of the ocean bottom into the liquid is discussed in this paper. The upward folding of the ocean bottom has been idealized by means of an irregularity in the form of a rectangle intruding into the liquid and the evaluation of the displacement component at any point of the solid medium has been carried out in two stages. First, the change in the incident mode of the surface wave due to the presence of the rectangular irregularity has been determined, and second, the subsequent change of the resulting displacement components due to the termination of the liquid layer and the step change in elevation of the solid medium at the continental margin has been discovered. Finally, numerical calculation has been made to determine the attenuation of the microseismic waves of different periods due to the presence of the rectangular irregularity at the ocean bottom.

抄録全体を表示

A boron treated copper bearing HSLA steel containing austenite formers like manganese and nickel, somewhat lower in amount than that in HSLA 100 variety of steel is chosen for the study. The role of thermomechanical processing on the microstructure and mechanical properties of the above steel has been investigated. Differential scanning calorimetric study is carried out for understanding the precipitation behaviour of copper in HSLA steel under the influence of boron. The microstructure of the experimental steel is found to consist of laths of martensites and bainite. MA constituents of ribbon like morphology are observed at the lath boundaries. Higher strength properties of the steel are attributed to the presence of finely distributed precipitates of copper and microalloy carbides.

抄録全体を表示

The effect of composition and controlled thermomechanical process parameters on the mechanical properties of HSLA steels is modelled using the Widrow-Hoff's concept of training a neural net with feed-forward topology by applying Rumelhart's back propagation type algorithm for supervised learning, using a Petri like net structure. The data used are from laboratory experiments as well as from the published literature. The results from the neural network are found to be consistent and in good agreement with the experimented results.

抄録全体を表示

An unsupervised learning technique and an associative memory have been used for encoding weights by a special type of Petri network named Petri neural net for modelling the influence of alloying elements on the final property of the high strength low alloy steel. The combined effects of alloying elements for different strengthening mechanisms is predicted when weights and threshold values are chosen on the basis of metallurgical understanding. The technique is found to be effective to create an associative memory of input-output relations in unknown data sets so that the same can be subsequently be used as a predictive tool.

抄録全体を表示

Primarily from the point of view of improvement of yield strength due to additions of niobium, titanium and boron in HSLA steels, the experimental steels are divided into five classes. The data are then supplied for learning a Self Organising Map (Kohonen network). It is found that the network with six neurons possesses better capacity of prediction with unknown data. Another effort of clustering the steels according to its major strength contributing mechanisms is also made. But the capacity of the network to cluster unknown data is found to be rather poor and has failed to follow from the metallurgical principles. To avoid this limitation, Learning Vector Quantisation method is adopted to impart a certain amount of supervision in the learning process and it is found that the training pattern of the network attains a good convergence thereby leading to a good predictive ability.

抄録全体を表示

Two new partially saturated tricyclic ring systems, , a, , , , 10, 10a, 11-octahydro-11-oxodibenz [, ] oxepins (a and ), and -thiepins (a and ) were synthesized. Compounds a and were desulfurized to give a pair of isomeric 2-methylbenzoylcyclohexanes (10a and 10). Deuterated a and (11a and 11) were prepared starting from butadiene- (12). The stereochemical features of a (trans), (cis), a (trans) and (cis) are compared with those of 10a, 10, 11a and 11 on the basis of proton nuclear magnetic resonance data.

抄録全体を表示

The ability of Climacodon septentrionalis to immobilize and kill a mycophagous nematode (Aphelenchoides sp.) in vitro is described for the first time. Two isolates produced droplets (20–45 μm in diameter) that formed at the apices of tall, stalked, and branching secretory cells (700–

,500 μm tall). On 2% modified malt extract agar, nematodes became enveloped in the droplets, which restricted their ability to move and resulted in complete immobilization and death within several hours of contact. The rate of decomposition of the nematodes varied considerably, with most individuals persisting for weeks whereas others were degraded within several days and appeared to be colonized by dense hyphal growth. This study provides the first documentation of a non-agaricoid fungus producing secretory cells that are able to immobilize nematodes.

抄録全体を表示

Horizontal plate anchors are widely used in civil engineering constructions to resist vertical pulling loads. The available theoretical model suggested by Vesic to estimate the breakout resistance of plate anchors is in significant error, particularly for dense sandy soils. A theoretical model assuming a curved surface of failure through the surrounding soil, to evaluate the ultimate breakout resistance of horizontal plate anchors, has been proposed. It successfully brings out the concept of characteristics relative depth beyond which the breakout factor reaches a constant final value. It is capable of predicting breakout factors for wide range of values of angle of shearing resistance of sand.

抄録全体を表示

The aim of the present study was to evaluate the predation efficacy of Bdellovibrio bacteriovorus on multidrug-resistant (MDR) or extensive drug resistant (XDR) gram-negative pathogens and their corresponding biofilms. In this study, we examined the ability of

. bacteriovorus to prey on MDR and XDR gram-negative clinical bacteria, including Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii. Results showed that

B

. bacteriovorus was able to prey on all planktonic cultures, among which the most efficient predation was observed for drug-resistant

E

. coli, with a .11 log10 reduction in viability. Furthermore,

B

. bacteriovorus demonstrated promising efficacy in preventing biofilm formation and dispersing the established biofilm. Reductions in biofilm formation of

E

. coli, K. pneumoniae, P. aeruginosa, and A. baumannii co-cultured with

B

. bacteriovorus were 65.2%, 37.%, 44.%, and 36.%, respectively. Meanwhile, the established biofilms of

E

. coli, K. pneumoniae, P. aeruginosa, and A. baumannii were significantly reduced by .%, 81.%, .%, and 79.%, respectively. A visual analysis supported by scanning electron microscopy demonstrated the role of

B

. bacteriovorus in removing the established biofilms. This study highlights the potential use of

B

. bacteriovorus as a biological control agent with the capability to prey on MDR/XDR gram-negative pathogens and eradicate biofilms.

抄録全体を表示

Nアルキル,:,10-ペリレンテトラカルボン酸モノアンヒドリド=モノイミド[a～]と芳香族アミン(アニリン,p-トルイジン,p-アニシジン,,-キシリジン,-アミノナゾベンゼン,およびo-フェニレンジアミン)を縮合して非対称型,:,10-ペリレンビス(ジカルボキシミド)誘導体-N-アルキル-N'-アリール-,:,10-ペリレンビス(ジカルボキシミド)(〔a～〕,〔a～〕,〔a～〕,〔a～〕,〔a～〕,および〔10a～〕)を合成した. これらの各誘導体はすべて赤色系の色相を示し, 顔料試験の結果N-ブチル-N'-アリール-,:,10-ペリレンビス(ジカルボキシミド)(たとえば〔〕や〔〕)がとくにすぐれた耐光性を示した.

抄録全体を表示

A sample of [

3H

] tobrarnycin (

5

, 000 Ci/Mole) has been synthetized and incubated with
the bacterial ribosome and its subunits. The results obtained show that this antibiotic has
two types of binding sites. The primary one is probably responsible for the inhibition of
protein synthesis whereas the secondary one is probably related to the misreading and reading
tiirough of the messenger RNA.

抄録全体を表示

Simultaneous measurements of the total geomagnetic field intensity by the same type of the proton precession magnetometers at two stations in NW Turkey have been taken cooperatively by a research group since December 1970. Up to the end of July 1971 mainly three probable local magnetic changes were observed. It was seen that after a decrease in the local field at a magnetic station (Erdek) a few earthquakes occured at either nearly N or S of that station, and after an increase in the local field an earthquake took place nearly W of the same station. In this paper the data and some results of the first part of observations are given.

抄録全体を表示

Nine isoquinoline alkaloids belonging to the protoberberine, proaporphine and bisbenzyl-isoquinoline series were isolated from Caryomene olivascens (Menispermaceae). Four compounds are new : (-)-2-norlimacine (), (-)-caryolivine (), (+)-, 2-dehydro-2-norlimacusine () and N-formylstepharine (). The last one is the first N-formyl derivative to be reported in the proaporphine group. Its biogenetic origin is discussed. Structures were established on the basis of 360 MHz (FT) nuclear magnetic resonance measurements and also by chemical correlation in the case of .

抄録全体を表示

Effects of noise exposure on aural reflex (AR) were investigated. The threshold of AR (ART) was measured in two groups exposed to occupational noise (Group A and ) by the electro-acoustic impedance bridge (Madsen, ZO-72). White noise (WN), and pure tones of and kHz were selected as activating stimuli for AR, and ARTs for these stimuli (ART_WN, , ) were determined respectively. The results were compared with the ARTs in the normal group (Group C) reported by the authors previously. Group A consisted of 31 male workers exposed mainly to steady noise, and Group included 65 male workers exposed maily to impulsive noise. Group C consisted of 50 males and 50 females, who had normal hearing acuity without any history of occupational noise exposure (Fig. 12). Mean age was 37.2 years in Group A, 49. in Group . Mean period of noise exposure was 13. years in Group A, 26. in Group . In both groups, the hearing loss was observed in the higher frequency region at and/or kHz, while normal hearing acuity was reserved at kHz (Fig. and ). Because of no significant difference between Group A and in each of the mean ARTs (Table ), Groups A and were summarized as the exposed group to noise. ARTs for three different stimuli (ART_WN, , ) in the exposed group showed significant differences compared to those in the non-exposed group (Group C); i.. mean ART_WN was 92.0 dB SPL in the exposed group and . in Group C, mean was 93. dB SPL in the exposed group and 96.2 in the non-exposed, mean was 102. dB SPL in the former and 97. in the latter group (Table ). There was a significant negative correlation between the hearing level at kHz () and the value of [-] (Fig. 14). The difference between and ART_WN, [-ART_WN], was significantly reduced in the exposed group; i.. . dB in the exposed group and 12. in Group C (Table ). For the purpose of our study, the exposed group was re-classified into another two groups according to their HLs at and kHz; i.. Group (HL(

4

k+

8

k)/2<25 dB) and Group (HL(

4

k+

8

k)/2>__=25 dB). The mean values of ARTs and HLs in Groups , and C, which are summarized in Table , show two interesting points. First, the significant elevation of ART_WN is observed not only in Group but also in Group with normal hearing acuity. Second. the lowering of is observed in Group only. These results indicate that the elevation o ART_WN probably depends upon the exposure history to occupational noise but not upon the hearing loss, and that lowering of may be caused by the hearing loss of the subjects in the higher frequency region. These estimations may be supported by the fact that [-ART_WN] was . dB in group and 0. dB in Group (Table ). Since damages of outher hair cells (OHC) in the Corti's organ do not always lead to hearing loss, it is conceivable that the reduction of [-ART_WN] is the results of the widening of the critical band width for AR due largely to the damage of OHC caused by the occupational noise exposure. Under this conception, the value of [-ART_WN] may be used as a sensitive and objectibe indicator for detecting and evaluating the early stages of noise-induced hearing impairment and individual susceptibility to noise.

抄録全体を表示

Two new polyacetylene compounds (, , 12)--acetoxy--isovaleryloxytetradeca-, , 12-trien-, 10-diyn-14-ol (), and (, , 12)--acetoxy--(2-methylbutyryloxy)tetradeca-, , 12-trien-, 10-diyn-14-ol (C) have been isolated along with (, , 12)--acetoxy--senecioyloxytetradeca-, , 12-trien-, 10-diyn-14-ol (A) from Atractylodes Rhizome (Karabyakujutu). The structures of these compounds were determined on the basis of their spectral data.

抄録全体を表示

The phase diagrams of the Ni-Mo- and Ni-W- ternary systems in the region of less than 50mol% were constructed by thermodynamic calculation, based on the data obtained by thermodynamic measurement of the related materials. We found three ternary eutectic points and three or two ternary peritecto-eutectic points as follows:
:L (1365K, 71.mol%Ni-.0mol%Mo-.mol%)=(Ni)++
:L (1355K, 62.mol%Ni-2.mol%Mo-30.mol%)=++
:L (1445K, 42.0mol%Ni-30.mol%Mo-10.mol%)=(Ni)+NiMo+
:L (1812K, 34.mol%Ni-42.mol%Mo-.mol%)+MoB=+
P₂:L (1633K, 42.mol%Ni-40.mol%Mo-17.mol%)+Mo=+
:L (1812K, 53.mol%Ni-33.mol%Mo-12.mol%)+Mo=NiMo+
:L (1622K, 51.0mol%Ni-31.mol%W-17.mol%)=(Ni)+W+
:L (1260K, 71.0mol%Ni-.0mol%W-.0mol%)=(Ni)++
:L (1291K, 65.mol%Ni-.mol%W-29.mol%)=++
:L (2115K, 23.mol%Ni-43.mol%W-33.mol%)+WB=+
P₂:L (1657K, 48.mol%Ni-33.mol%W-18.0mol%)+=W+
The calculated phase diagrams are expected to be useful for the development of new Ni-based heat-, corrosion- or wear-resistance alloys.

抄録全体を表示