巻号一覧
1 巻, 4 号
選択された号の論文の6件中1～6を表示しています
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Yoshitsugu MONUKI1932 年 1 巻 4 号 p. 165-167
発行日: 1932/11/20
公開日: 2008/02/29
ジャーナル フリーPDF形式でダウンロード (129K) -
田村 健治1932 年 1 巻 4 号 p. 168-170
発行日: 1932/11/20
公開日: 2008/02/29
ジャーナル フリーFour individuals of carp, Cyprinus carpio, were killed by destroying the brain and stored at 10°, 15°, 20°, and 25°C. respectively. Their electric resistance was measured from time to time by putting one platinum electrode, 1cm. in length and 0.7mm. in diameter, through either 5th or 20th scale on the lateral line and the other platinum electrode of the same dimensions through the skin at a distance of 2cm. from the former either dorsally, ventrally, anteriorly, or posteriorly. The circuit was closed as shown in Fig. 1. The electric resistance remained constant for varying intervals according to the temperature of storage, and then fell in such manners as illustrated in Fig. 2. The temperature coefficient for the duration of the initial constant electric resistance was found to be 3.9 according to Arrhenius's formula. It should be noted in this connexion that the expressed juice of fish-meat, kept at various temperatu es, did not show any change of electric resistance, but a fish, having been frozen at -21°C. for four days, was found decidedly less resistant electrically when thawed at 25°C. The change of e ?? ectric resistance of fish-body during the storage seems, therefore, not due to augmentation or diminution of the disintegration products in the fish-body but to some physical or physico-chemical changes of the tissues caused by either autolysis or both autolysis or both autolysis and bacteri ?? l decomposition.抄録全体を表示PDF形式でダウンロード (168K) -
岡田 光世1932 年 1 巻 4 号 p. 171-177
発行日: 1932/11/20
公開日: 2008/02/29
ジャーナル フリーBy the aid of the principle of dynamical similitude applied on the equations of natural convection in the steady state with an assumption that the coefficient of eddy diffusivity is proportional to the velocity V and the linear dimension L of the general flow, the present author(1) has previously come to the following conclusions:
1. Whenever the distribution of temperature on the similar boundtiries is similar, the distribution of temperature at any other points as well as the velocity of the general flow becomes similar in the steady state.
2. The relation between velocity of the general flow and the difference of temperatures at any assigned similarly located points θ is given by V ?? (θL)1/2
In the summer of 1930 the circulation of air.in a cold-storage warehouse was studied. The temperature and the three components of the general flow of air in several parts of the warehouse were observed and they were afterwards reproduced by models of about one seventh (1/7, 1/6.8) of the actual scale in linear dimension (Fig. 3). A kind of optically registering pendulum current meter as shown in Fig. 1 was deviced for the measurement of very weak current in the dark rooms such as the cold storage warehouse. In the models the velocity component along a lengthwise vertical plane was observed by following the motion of patches of smoke supplied from a reservoir, the direction having been sketched.
The results of model experiments are compared with those of the actual observations with regard to the following points:
(i) the relative values of temperature θ-t=(θ-_??_1)/(_??_2-_??_1), where _??_1 and _??_2 are the means of temperature of the cooler and the warmer halves of the general circulation respectively-calculated in the case of models t' with those in the actual cases t (Fig. 5), (ii) the direction of the general flow, sketched in the case of models (→ or- →) with that of the corresponding component of velocity in the actual cases (⇒), obtained by the combination of the observed components (Fig. 4) and finall ?? (iii) the speed of flow in the just mentioned direction in the case of models V' multiplied by the factor (ΔθL/Δθ'L')1/2, where Δθ=_??_2-_??_1, Δθ' is the same thing for models and L/L'=7 or 6.8, with the magnitude of the corresponding component of velocity in the actual cases V (Fig. 7).
From the above comparisons, we can ascertain that the conclusions 1. and 2. drawn from the previous study are valid in the case of studying the steady circulation of air produced by natural convection in a cold-storage warehouse.抄録全体を表示PDF形式でダウンロード (1077K) -
木俣 正夫1932 年 1 巻 4 号 p. 178-185
発行日: 1932/11/20
公開日: 2008/02/29
ジャーナル フリーIt is well known that the reactions of the media play an important part on the bacterial growth. However, our knowledge of relationship between the thermal death rates and the reactions of the media is rather poor, only a few papers having been published on it.
BIGELOW and ESTY(1) (1920) found that the thermal death time of the typical thermophilic bacteria comes earlier under acidic condition than under neutral condition. WEISS(2) (1921), ESTY and MEYER(3) (1922) reported that the addition of acids or salts shorten the thermal viability of spores of Clostridiurn botudinum. MYERS(4) (1928) pointed out that the thermal death point and the thermal death t ?? me of Bact. coli are lower and shorter in alkalin condition than that in neutral condition. WOLF and FOSTER(5) (1921) also studied the effect of different hydrogen-ion concentrations on the thermal death rates of plant pathogens, and ORR(5) (1918) studied the effect of varying hydrogen-ion concentrations upon the rate of death of the spores of Bacillus pseudotetanicus suspended in solution containing HCl at different temperatures. COHEN(6) (1922) studied the effect of varying hydrogen-ion concentrations and different temperatures (0°C-30°C) on Bact. coli and Bact. typhosum, and found that the death times become shorter with the hydrogen-ion concentration.
I studied the relation of the thermal death point to the time and pH-value in Escherichia coli and 5 putrefactive bacteria-Kruthia zopfi, Pseudomonas ovulis, Achromobacter multistriatum Seratia sp., Micrococcus sp.
The bacteria cultivated for 48 hours at 28°C (for Escherichia coli, 24 hours at 37°C) were taken in broth of 0.1c c., and put into 10c.c. of the sterilized buffer solutions (pH value= 10.14-2.27), and were shaken carefully. Then they were put into ampullae (capacity, ca. 0.1c.c., dia. ca. 3mm ), sealed, heated at a definite temperature, after a definite time were cooled in water. The ampullae were disinfected with alcohol, the ends of them were cut off, then their contents were pipetted into the agar media with sterilized capillary, and were poured into the petri dishes.
Besides, I have used the ampullae, unheated and stood 4 hours, as a control.
The results obtained are shown in the tables 1-6.
From the tables it is clear that the effect of hydrogen-ion concentration on the thermal death points depends on the kind of bacteria, that the thermal death points and the thermal death times depend on the hydrogen-ion concentration, that the thermal death times at high temperature are shorter than that at low temperature in the same hydrogen-ion concentration, that the thermal death times of the same temperature are the longest in about the neutral condition, that the thermal death points of the same heating times are the highest in about the neutral condition, and that the effect of hydrogen-ion concentration at high temperature are greater than that at low temperatnre.抄録全体を表示PDF形式でダウンロード (382K) -
川口 武男, 關根 宗三1932 年 1 巻 4 号 p. 186-190
発行日: 1932/11/20
公開日: 2008/02/29
ジャーナル フリーThe freshness or degree of decomposition of fish-meat can be given in terms either of its pH-values, amount of NH3-N or of Amino-N(1), since these items change by degrees during the storage owing to autolytic as well as bacterial actions. KAWASAKI(2) has pointed out that the meats of fish and others, to which some quantity of acid or alkali was already added to change their original pH-value, which remained intact or approach the neutral point of pH-value when subjected to heating. The present authors have heated the fish-muscle, which was at first acidic by autolysis and bacterial decomposition, with the results summarized in Tables 1-7. The shift of pH-value by heating toward the neutral point was within the limit of ±0.4 in our experimental conditions.抄録全体を表示PDF形式でダウンロード (231K) -
相川 廣秋1932 年 1 巻 4 号 p. 191-198
発行日: 1932/11/20
公開日: 2008/02/29
ジャーナル フリーPDF形式でダウンロード (631K)
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