摘要:

An examination was made of various kinds of diatomite brick, in order to ascertain how the thermal conductivity of diatomite found at Quesnel in British Columbia compared with the conductivities of some other diatomites. A brief description is given of the difficulties which attend any endeavor to measure thermal conductivity with accuracy above 1500° F. and which necessitate the limiting of the investigation to temperatures between atmospheric temperature and 1500° F. Of the samples investigated the Quesnel brick was found to be the best thermal insulator with the exception of a brick consisting of natural Californian diatomite.

ISSN:1923-4287    

DOI:10.1139/cjr34-090

出版商:NRC Research Press    

年代:1934

数据来源: NRC

摘要:

A consideration of recently published results on the transmission of longitudinal waves in cylinders of liquid, in hollow tubes and in solid rods shows that the first two cases give velocity-frequency curves which are quite similar to each other but different from that obtained with the third case. The reason for these results is discussed and is shown to be most probably the relative importance of shear forces in each case. The effect of viscosity on the phase velocity of longitudinal waves is considered, and it is shown that the classical method of introducing viscosity leads to erroneous results.

ISSN:1923-4287    

DOI:10.1139/cjr34-091

出版商:NRC Research Press    

年代:1934

数据来源: NRC

摘要:

Some 300 samples of hard red spring wheat, 50 of amber durum wheat and 75 each of oats and barley, covering the entire moisture range of commercial importance, were employed in the comparisons. Provision was made for statistical estimation of sampling errors, errors of method and errors of observation. A two-stage drying procedure was employed for the vacuum oven determinations which were taken as the reference standard. Sampling errors, average difference between identical ovens and errors due to daily fluctuations were all larger than the standard deviation of duplicates ("experimental error"), the sampling error being the largest.A comparison of the Hobart and Wiley grinders shows the latter to be superior for preparing wheat for the 130 °C. air oven determination. The air oven consistently underestimates the moisture content of all the grains tested, as compared with the vacuum oven, the deficit increasing with the actual moisture content. This systematic bias may be eliminated by means of a linear correction equation. After allowing for the observed sampling errors and errors of the vacuum oven determination, the net standard error of prediction with the air oven using a Wiley mill is, with hard red spring wheat 0.24%, with amber durum wheat 0.12%, with barley 0.20% and with oats 0.20% moisture.The Brown-Duvel method also underestimates the moisture content, this deficit also increasing with the actual moisture content in the case of spring and amber durum wheat. After applying a correction equation to eliminate the systematic bias, the net standard error of prediction of moisture by this method was found to be: with hard red spring wheat 0.16%, with durum wheat 0.09%, with barley 0.12% and with oats 0.13%. The Brown-Duvel method, therefore, when carefully operated makes possible a more consistent estimate of the actual moisture content, as determined by the vacuum oven, than does the 130 °C. air oven method. As with the vacuum oven, both the 130 °C. air oven and the Brown-Duvel appear to be subject to slight variations affecting all the determinations made on any particular day.

ISSN:1923-4287    

DOI:10.1139/cjr34-092

出版商:NRC Research Press    

年代:1934

数据来源: NRC

摘要:

Forty-three species of the Tortricid genusPeroneaare dealt with, comprising all the species known to occur in Canada at the present time and including practically all of the North American ones. Characters found in both the male and female genital organs have been used as a means of specific differentiation and there are eight sets of figures illustrating these organs. The range of variation in color and pattern of the individual species is briefly discussed and records of distribution and larval food-plants are given as far as present knowledge permits. Seven species new to science are described.

ISSN:1923-4287    

DOI:10.1139/cjr34-093

出版商:NRC Research Press    

年代:1934

数据来源: NRC

摘要:

A comparative study was made of three interspecific wheat crosses with regard to the relationship between seed plumpness and plant character in theF2generation. In general, the degree ofvulgare-ness of the plants was associated with the degree of shrunkenness of the seeds, the most shrunken seeds producing the mostvulgare-like plants. However, many shrunken seeds did not producevulgare-like plants and many plump seeds did not produce plants resembling the 14-chromosome parental variety. Desirablevulgare-like plants were obtainable from each plumpness class, the largest proportion being from the shrunken seeds. Plants from shrunken seeds that were germinated under ideal conditions proved to be no morevulgare-like than those which survived sowing under rigorous conditions in the field. Thedurum×vulgarecross was high in percentage of shrunken seeds and relatively high in the proportion ofvulgare-like plants from plump seeds. Thedicoccum×vulgarecross was low in proportion of shrunken seeds and had relatively fewvulgare-like plants from plump seeds. In these crosses it would appear unnecessary for the breeder to pay attention to differences inF2seed plumpness. Thepersicum×vulgarecross showed a fair proportion of shrunken seeds but had relatively fewvulgare-like plants from plump seeds. In this cross it would appear advisable to have an abundance ofF2seeds and sow only the more shrunken half of them.

ISSN:1923-4287    

DOI:10.1139/cjr34-094

出版商:NRC Research Press    

年代:1934

数据来源: NRC

摘要:

(i) Chiasma frequency at metaphase has been studied in the following species and species hybrids:A.strigosaSchreb.;A.brevisRoth;A.WiestiiSteud.;A.barbataPott;A.abyssinicaHochst. (2 strains);A.sterilisL. (2 strains);A.sativaL. var. Radnorshire Sprig; a triploid hybrid,A.barbata×A.strigosa; a pentaploid hybrid,A.abyssinica"naine" ×A.sterilismaxima; and a hexaploid hybrid,A.sterilis(white) ×A.sativavar. Radnorshire Sprig.(ii) The various factors that may affect chiasma frequency are discussed and it is concluded that there may be some parallelism between closeness of relationship and similarity in chiasma formation, as genetical control is one factor affecting the process. The results are examined in the light of this conclusion.(iii) The homogeneity of species in respect to proportion of bivalents with zero, one, two, three, or four chiasmata is tested by means of χ2. The test indicates no significant difference between the closely related diploid species,A.brevisandA.strigosa, but both differ significantly from the less closely relatedA.Wiestii. The differences between the tetraploid species are of questionable significance, those between the hexaploids, insignificant. It is suggested that the lack of significant differences among these last-mentioned forms may be due to a multiplication, in the polyploid, of genes favoring high chiasma frequency. In this way a maximum effect might be brought about, and inter-specific differences with respect to this character would consequently be lacking.(iv) High chiasma frequency in the hybrid might be regarded as strong evidence of homology, and consequently of relationship between parental forms. The triploid hybrid,A.barbata×A.strigosashows a high chiasma frequency at metaphase, a condition consistent with the close relationship of the parental forms. The pentaploid hybrid, as might be expected, has a low chiasma frequency. The chiasma frequency of the hexaploid hybrid,A.sterilis×A.sativavar. Radnorshire Sprig does not differ significantly from that of its low-frequency parent,A.sterilis. Cytological observations in this hybrid, therefore, reveal only a slight degree of non-homology between parental chromosomes. It is noted that there are certain characters ofA.sativavar. Radnorshire Sprig that suggest affinity withA.byzantina, a species commonly associated withA.sterilisin relationship schemes.

ISSN:1923-4287    

DOI:10.1139/cjr34-095

出版商:NRC Research Press    

年代:1934

数据来源: NRC

摘要:

Five cultures of BCG have been shown to consist primarily or entirely of R type tubercle bacilli and to resemble R types from other sources. When received one culture contained a few S types which were isolated. The other four cultures appeared to consist entirely of R types. After a long series of cultures, particularly in slightly alkaline Proskauer and Beck's fluid, dissociation occurred and S types were isolated from two strains; no stable S types could be recovered from two additional strains.The R, or ordinary BCG produced only localized infections, the S forms produced fatal progressive tuberculosis in guinea pigs. The degree of tissue involvement in fatal cases was generally less than with typical virulent tubercle bacilli.By means of complement fixation reactions it was shown that the S form recovered from BCG cultures, like typical S virulent mammalian tubercle bacilli, contains a specific antigenic substance which is lacking in the ordinary BCG and other R forms of the species. Animals immunized with S organisms are shown to develop a specific S antibody which is not present in the serum of animals treated with R organisms or the ordinary form of BCG. It is suggested that this lack of antigenic substance in the BCG militates against its effectiveness as an immunizing agent.

ISSN:1923-4287    

DOI:10.1139/cjr34-096

出版商:NRC Research Press    

年代:1934

数据来源: NRC

摘要:

The iodimetric estimation of acetone is directly related to two factors: (1) the enolization of acetone by alkali, and (2) the relative velocities of (1) and the reaction between alkali and iodine. The experiments necessary to emphasize these factors indicate the great rapidity of these two reactions at 25 °C.

ISSN:1923-4287    

DOI:10.1139/cjr34-097

出版商:NRC Research Press    

年代:1934

数据来源: NRC

摘要:

A considerable number of highly substituted acrylic acids or their lactols have been synthesized, and the Grignard reagent used to differentiate between the two possible structures. Acetyl chloride was found to be a satisfactory confirmatory agent, giving chlorides with the lactols, but not reacting with the open-chain acids. From the available evidence it is concluded that the differences may be attributed tocis-transisomerism.Two other series of ketonic acids were investigated with both reagents; the Grignard reagent indicated mostly open-chain structures. The use of acetyl chloride led to a variety of products; by varying the procedure, dimers of undetermined structure, unsaturated lactones, enolic acetates, and methyl esters were obtained.Cyclohexanone gave cyclohexenyl acetate with acetyl chloride.The mechanism of the reactions is discussed, as well as the evidence for the possible structures of derivatives of levulinic acid. A mechanism is suggested to account for the formation of enolic esters and unsaturated lactones of enolized ketonic acids.

ISSN:1923-4287    

DOI:10.1139/cjr34-098

出版商:NRC Research Press    

年代:1934

数据来源: NRC

摘要:

When attempts were made to add substances of the type HA to α-methoxybenzalacetophenone in the presence of an alkaline catalyst, it was found that the components were largely recovered unchanged, except in the case of cyanoacetamide; the addition product from the latter is a hydropyridine. The hydropyridine gives two distinct series of reaction products; in the first, the substances are all pyridine derivatives and always contain a methoxyl group. In the second, partial degradation has taken place, giving rise to cyclic derivatives of a δ-ketonic acid.

ISSN:1923-4287    

DOI:10.1139/cjr34-099

出版商:NRC Research Press    

年代:1934

数据来源: NRC