South African solar radiation survey 1937-38

The results of the physical measurement of the total amount of sun and sky radiation and the cooling temperature at 6 stations in the Union may be summarized as follows: A. Radiation. 1. How does the amount of radiation at the inland stations compare with that at the coastal stations? The amount of radiation obtained at the inland stations exceeded the amount at the coastal stations all the year round. 2. Which station received the greatest, and which the smallest amount of radiation during the course of the year? During nine out of twelve months the greatest amount of radiation was obtained in the climatic zone of the high veld. During the remaining three months (December, January and February) the greatest amount was received at Cape Town. The smallest amount of radiation was obtained during all twelve months at the coastal stations. In five of the twelve months Cape Town recorded the least, during five other months Durban received the smallest amount. 3. During which month was the greatest and during which the smallest amount of radiation obtained at each station? At each station the greatest amount of radiation occurred during the months November or December, 1937. The smallest amounts were recorded during the winter months of July, 1937, and June, 1938. 4. What was the ratio between the greatest and the smallest amount of radiation at each station? Johannesburg registered during the month of maximum radiation twice as much solar energy as it did during the month of minimum radiation. Comparable ratios were: 3.4:1 for Cape Town; nearly 3:1 for Port Elizabeth and 2:1 for Durban. 5. How did the amount of radiation at each station vary during the course of the year? The amount of radiation at Johannesburg during the course of the year was rather irregular. At Bloemfontein and Nelspoort the increase of the monthly amount with the increase of the altitude of the sun was progressive. At Durban great variations in the amount of radiation was registered from month to month. Port Elizabeth showed a fairly regular distribution over the year. In Cape Town the amount also increased and decreased steadily in accordance with the sun's altitude and showed particularly high readings in December and January. 6. How do the total amounts of radiation recorded at the stations during a period of six months compare with each other? During the first half year under investigation the total amount of sun and sky radiation was largest at Bloemfontein, next in amount was that at Johannesburg and at Nelspoort Sanatorium. At the coast, Cape Town and Port Elizabeth had an approximately equal amount of radiation. Durban's amount was distinctly smaller. Durban, being the station with the smallest amount of radiation during the first half year, recorded 22 per cent. less than Bloemfontein which had the greatest amount. The second half year showed a greater amount of radiation at Johannesburg than at the coastal stations. These recorded fairly similar amounts during the period. The total for the year was distinctly larger at Johannesburg than at the three coastal stations. 7. How does the amount of radiation obtained in South Africa compare with the amount in Nairobi (Kenya), Davos (Switzerland) and Bad Nauheim (Germany)? In winter the amount of sun and sky radiation at Johannesburg was distinctly larger than at Davos situated at a similar altitude above sea-level and it was 5 to 10 times larger than at Bad Nauheim at a low altitude. During two months in midsummer the amount at Davos was slightly larger than at Johannesburg during the comparable period. Nairobi experienced a greater amount of radiation during the six months under investigation than any of the other places concerned in this comparison. The ratio between the highest summer and lowest winter reading per month was 2.0:1 at Johannesburg, 4.5:1 at Davos and 10.4:1 at Bad Nauheim. The yearly total amount at Johannesburg was 122 per cent. of what was received in Davos; Bad Nauheim obtained only 69 per cent. of that amount. B. Cooling temperature. 1. During winter the mean values of the cooling temperature showed the greatest extremes at the inland stations, particularly at Johannesburg. Bloemfontein recorded higher readings at night, and Nelspoort distinctly lower recordings during day-time than Johannesburg. The average conditions at the three coastal stations showed no very distinct differences. Throughout the year Durban's mean cooling temperature values were the highest. Next in order was Port Elizabeth, followed by Cape Town. 2. The rapid decrease of cooling temperature in the afternoon continued after sunset at the inland stations but not at the coastal stations. In the latter the rapid decrease only lasted until sunset, immediately after which the drop became much more gradual. 3. The average increase of the mean cooling temperature from winter to summer was great at the inland stations, but small at the coastal stations. 4. In winter the monthly average cooling temperature was distinctly lower at the inland than at the coastal stations, in summer this difference was not pronounced. 5. The mean maximal cooling temperatures showed no regular difference between the interior and the coast, whereas the mean minimal readings were distinctly lower at the inland stations. 6. The absolute highest cooling temperature of 52.0° was registered at Port Elizabeth in August and in January, the absolute lowest reading of 4.0° was recorded at Johannesburg in September, 1937.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. 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Some aspects of solar radiation in its relation to cattle in South Africa and Europe

Two aspects of solar radiation in its relation to cattle in South Africa and Europe are considered. The first is the solar radiation itself and the factors influencing its intensity and total amount incident on a horizontal surface at various places. The second is the question of how much radiation is absorbed by the body surface of cattle in South Africa and Europe. A comparison of solar radiation in South Africa and Europe shows the following facts: 1. The angle of incidence of the solar rays is distinctly larger in South Africa than in Europe. 2. The midday intensities in Davos (Switzerland) are on an average nearly equal to those at Johannesburg (South Africa); at Kew (England) they are on an average lower than at Durban (S.A.). 3. The days are shorter in South Africa during summer, but longer during winter. 4. The number of hours with bright sunshine is much greater in South Africa during the whole year, particularly during winter. 5. The monthly total, amount of sun and sky radiation is equal or slightly greater in summer; it is, however, markedly greater during winter in South Africa than in Europe. 6. The yearly total amount of incident radiation is 187 Kilogram Calories per square centimetre at the South African Inland Stations as compared with 103 Cals. / sq. cm. on the lowlands of central Europe. In Part II the total absorption of radiation from the sun, the sky, and that reflected from the ground on to the body surface of cattle under South African and European conditions is calculated. The discussion is limited to a few clearly defined examples. Figures of the amount of solar and sky radiation impinging on to the animal during a clear mid-summer and a clear mid-winter day are given, the animal either standing at right angles to the solar beam or facing the sun. The absorption of the incoming radiation is determined by reflection measurements on two brown bovine hides of different breeds (Sussex x Afrikaner and high grade Afrikaner) and figures of the absorption of direct solar and sky radiation and the absorption of radiation reflected from the ground are presented. From these data the total amount of radiation absorbed by the body surface of cattle is calculated. This amount is found to be strikingly high, e.g., more than 20,000 Kilogram Calories during a clear mid-summer day, regardless whether the animal is exposed on the high veld of South Africa, in the alpine region of Switzerland or on the lowlands of central Europe. A comparison of the total amount of radiation absorbed by the hairy coat and the heat produced by metabolism shows that cattle absorb nearly three times as much heat from radiation as they produce by metabolism during an equal period. The means of losing heat in order to keep their body temperature within safe limits are discussed from a physical point of view. With regard to a possible reduction of the amount of heat which has to be eliminated from the body, the effect of shade on the amount of incident radiation is. discussed. Figures of the reduction of the incoming solar radiation by natural and artificial shade are given which show that the amount of heat absorbed by the hairy coat of cattle can, by providing shade, be reduced to 30-40 per cent. of the amount which impinges on to the animal in the open veld.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Further observations on the scrotal skin temperature of the bull, with some remarks on the intra-testicular temperature

1. The temperature of the scrotal surface has been recorded at various air-temperatures within the range 10°C. to 40°C. (50°F. to 104°F.). 2. At low air-temperatures (10°C. to 25°C.) the temperature on areas I, II, and III gave a mean value of 32.0°C., 31.0°C., and 33.0°C.; at high air-temperatures (25°C. to 40°C.) the same areas were 33.9°C., 33.8°C., and 36.7°C. 3. Readings (28) of the skin-temperature underneath the hairy coat, taken simultaneously, gave mean values of 33.6°C. at low air-temperatures and 36.5°C. at high air-temperatures. 4. The mean body-temperature at which the high temperature group readings (15) were taken was 38.6°C. 5. Scrotal temperatures at areas I and II increased almost similarly with increasing air-temperature, i .e. slow increase at low air-temperatures (0.06°C. and 0.09°C. per 1° air-temperature increase) and more rapid increase at high air-temperatures (0.29°C. and 0.26°C. per 1° air-temperature increase). Scrotal temperatures of area III and skin-temperatures increased similarly with increasing air-temperature over the whole range of 10°C. to 40°C. air-temperature. The rate of increase for scrotal area III was 0.43°C. at 10°C. air-temperature, and 0.11°C. at 40°C. air-temperature. The rate of increase in the skin was 0.56°C. at 10°C. air-temperature, and 0.14°C. at 40°C. air-temperature. 6. The degree of contraction and relaxation of the scrotum, as indicated by its length from the dorsal to the ventral extremity, gave a mean value of 24.2 cm. at low air-temperatures and 29.0 cm. at high air-temperatures, a difference of 4.8 cm. 7. From limited observations on the body-temperature, at high air-temperatures only, there appears to be a highly significant relationship between the body-temperature and that o£ the air and scrotal areas I, II, and III. There was no significant relationship between body and skin-temperature. 8. An observation was carried out at artificially created low air-temperatures. The bull was exposed to a temperature of 4°C. to 6°C. for six hours. 9. Under these conditions scrotal area I increased immediately from 30°C. to 33°C. It then decreased and fluctuated between 31°C. and 32°C. During the following 4 hours, scrotal area II always showed lower temperatures than area I (up to 3°C.) . Scrotal area III increased markedly at the beginning and then showed a slight tendency to decrease, but after one-and-a-half hours remained 2°C. to 4°C. lower than skin-temperature. 10. There was marked shivering, which began one-and-a-half hours after exposure, and continued until one-and-a-half hours after the bull was removed from the cooling chamber. 11. The pulse rate per minute varied from 66 to 62 in the cooling chamber and dropped from 64 to 58 within an hour after removal. 12. The respiration count was 16 per minute after six hours exposure and 13 per minute one hour after removal. · 13. The skin-temperature showed steady increase, up to 35°C. (air-temperature 4°C.). It then decreased continually to 32.6°C. at the end of the experiment, but a constant level had apparently not been reached. After removal from the cooling chamber, there was an increase of 3°C. within an hour. 14. The length of the scrotum decreased with a fall of scrotal and skin-temperature during exposure. There was marked relaxation upon removal to higher air-temperature. 15. The body-temperature increased by 1°C. at the commencement of exposure, and remained remarkably constant at about 39°C. throughout the exposure and after removal from the cooling chamber. 16. The intra-testicular temperature, measured with a thermo-needle, at an air temperature range of 15·2° C. to 37·8° C. remained within a narrow range, between 34.8°C. to 37°C. for the left testicle and 34.7°C. to 36.6°C. for the right testicle. 17. Artificial displacement of the testicle to close contact with the body resulted in an increased intra-testicular temperature of 2.5°C. and a decrease in the temperature of the scrotal area not overlying the testicle, of 6.0°C. and 3.2°C. The scrotal surface over the displaced testicle also increased considerably to 37.0°C. 18. The heat regulating mechanism of the scrotum is extraordinarily efficient in maintaining the testicular and scrotal surface-temperatures within a very narrow range at air-temperatures between 10°C. and 40°C. It is suggested that this efficiency is not purely physical, due to the action of air temperature on the contracted or relaxed scrotum. This suggestion is strengthened by the fact that scrotal areas I and II, in close contact with the testicle, behaved similarly but differently -to scrotal area III and the skin. It appears probable that vascular reaction accompanies scrotal contraction and relaxation. 19. The scrotal temperature reaction over that portion of the scrotum removed from close testicular contact, is extraordinary in that there was a very marked decrease in temperature to 28.2°C., i.e. 3.8°C. lower than air-temperature, and 8.8°C. lower than intra-testicular temperature (average for points 1 and 2). It is suggested that this reaction was an attempt by the temperature regulating mechanism of the scrotum to maintain the testicular temperature, which was raised by contact with the body , at the normal temperature for prevailing air-temperature.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.ab201

The absorptivity for solar radiation of different coloured hairy coats of cattle

1. The mean effective absorptivity for solar radiation of the hairy coats of cattle was determined. It was found that the colour of the hair is the most important characteristic in effecting the total percentage of radiation absorbed. 2. The mean effective absorptivity was found to be 49 per cent. for the hairy coat of a white Zulu, 78 per cent. for that of a red Afrikaner and 89 per cent. for that of a black Aberdeen Angus. 3. The difference in absorption due to the direction of the hair in relation to the direction of the incoming solar beam was found to be not more than 4 per cent. (usually 1 to 2 per cent.). 4. No appreciable difference was found between the absorptivity of an autumn and a winter coat of two Afrikaner beasts. The mean absorptivity of a Sussex winter coat was not more than 2 per cent. higher than that of a Sussex summer coat. 5. A comparison of the absorptivity of an Afrikaner autumn coat with the hair smoothed down and with the hair standing up showed no appreciable difference. 6. After clipping a long-haired Sussex winter coat to about ½ inch in length, the mean effective absorptivity was found to be 2 per cent. lower than on the unclipped curly hair. This smaller absorption was probably due to the slightly lighter colour of the clipped hair. 7. The comparison of six hairy coats of different shades of red and of different grades of smoothness showed that the mean effective absorptivity varied between 78 per cent. and 83 per cent. The above findings show that the colour is the most important factor effecting the absorptivity of hairy coats for solar radiation, and that direction of the hair, its smoothness or curliness and seasonal changes in the character of the coat are of secondary importance.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

The influence of solar radiation on the course of bluetongue

1. Experiments which clearly indicate the detrimental influence of solar radiation on the course of bluetongue are described. 2. Preliminary experiments were carried out during different seasons of the year in a limited number of sheep. Some of them were photosensitized against light with methyleneblue. During the course of the disease the sheep were exposed to solar radiation daily for several hours. 3. The result was, that the exposed sheep showed distinctly severer reactions than those kept in the stable. The strongest and most fatal reactions (6 out of 10 sheep died) were observed during a test conducted in February, when the solar radiation was very intense. Exposure during winter (June) had practically no influence on the course of the disease. 4. In order to verify these observations, two experiments on a large scale (60 sheep each) were undertaken on sheep subjected to the immunization process. Half the sheep were kept in the stable and the other half freely exposed to solar radiation. In each locality half of the sheep were shorn, the others remained unshorn. 5. The body temperatures and the nature of the clinical symptoms showed that the reactions were much more pronounced in the camp than in the stable. The symptoms of bluetongue were most pronounced in the shorn animals in the sun. 6. Since a distinct influence on the severity of bluetongue reactions was noticed in sheep photosensitized with methyleneblue, it is believed that sheep in the field may react very severely to this disease if they become photosensitized naturally. 7. Bronchopneumonia in sheep photosensitized with methyleneblue occurred on several occasions and developed sometimes very rapidly. This observation suggests that natural photosensitization in the field may partly be responsible for the bronchopneumonia which is frequently observed in sheep m the field reacting to bluetongue. 8. During the course of the above investigations, multiple haemorrhages and muscular degeneration, a lesion which had not been previously associated with bluetongue, were observed in the stabled as well as in the exposed sheep. This observation gives an explanation to the general weakness, torticollis and stiffness of the sheep reacting to bluetongue. 9. The unthriftiness frequently observed in sheep after immunization or natural infection can also be attributed to the muscular degeneration. 10. Since the influence of solar radiation on the course of bluetongue has definitely been established, particular attention should be paid to the time of the year when the immunization is carried out. On account of the fact that the severest reactions were observed in shorn sheep, immunization should preferably be undertaken on unshorn sheep. 11. The provision of shade for sheep which have been vaccinated or which contracted the disease naturally should be promoted wherever possible in order to exclude the harmful influence of solar radiation on the course of bluetongue.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

A preliminary note on the temperature of the scrotal skin of the bull and its relation to air, skin, and body temperature

(1) The scrotal, skin, and body temperatures of a Sussex bull have been measured in the open during the period 7.1.41 to 27.3.41, at a range of air temperature of 26.4°F., i.e., from 64.8°F. to 91.2°F. (2) There was a significant difference between the temperatures of the three areas of the scrotum. (3) There was no significant difference between scrotal temperature measurements taken on that side of the body exposed to direct sun's rays and those taken of the opposite side. (4) There was a significant relation between scrotal temperature and air temperature. (5) The mean skin temperature readings, taken on an area on the flank from which the hair had been removed, were 98.6°F. in the sun and 96.7°F. in the shade. (6) There was a relation between the skin temperature and the air temperature; an increase of 1°F. of air temperature resulted in an increase of skin temperature of 0.28°F. in the sun and 0.31°F. in the shade. (7) There was a significant difference between the skin temperatures taken in the sun and in the shade. (8) The range of body temperature was too small, i.e., 101°F. to 103.5°F., to find a definite correlation between body and air temperature. The observations must be repeated at higher and lower atmospheric temperatures to establish such correlation. (9) There was a direct correlation between body and scrotal temperatures. (10) The correlation between body and skin temperature showed that for 1°F. increase in body temperature the skin temperature increased 2.01°F. in the sun and 2.6° F. in the shade.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Studies on the photosensitisation of animals in South Africa. XI. The reaction of the sensitised Merino skin to radiation in different regions of the spectrum

1. The effect of sunlight on sheep artificially photosensitised with eosin and phylloerythrin was investigated. Glass filters were used to ascertain whether any of those rays readily absorbed by these dye-stuffs produced skin reactions. Small square test areas on the back of photosensitised sheep were exposed under these filters to solar radiation for various lengths of time, up to six hours. 2. A spectral distribution curve was calculated for the solar radiation at Onderstepoort for an altitude of the sun of 65° and 35° respectively. When this spectral distribution curve was combined with the absorption spectrum of eosin and phylloerythrin the resulting curve delimitated those regions of the spectrum which might be expected to yield skin reactions in the photosensitised sheep. The results may be summarised as follows: (a) The skin of closely shorn, non-photosensitised, adult merino sheep, exposed to solar radiation for several hours showed only a light erythema which rapidly subsided without oedema formation. (b) Sheep photosensitised with phylloerythrin (dried leaves of the Lantana camara plant) and subsequently exposed to sunlight, showed reactions which increased in severity depending on the duration of exposure. (c) The reactions of the skin of sheep photosensitised with eosin, were strictly confined to those parts of the spectrum where eosin strongly absorbs radiation, namely from wavelength 540-460 mµ, i.e. in the green and blue part of the spectrum. (d) The phylloerythrin absorption is spread over a much wider area than that of eosin. The phylloerythrin shows three regions of absorption namely a single band from 654 to 626 mµ (orange), a triple band between 610 and 510 mµ (yellow and green) and high absorption below 460 mµ (blue, violet and ultraviolet). The filter experiments showed that reactions in the skin of sheep photosensitised with phylloerythrin were restricted to parts of the spectrum where radiation is absorbed by phylloerythrin, namely the region between 650 and 380 mµ, which includes practically all visible light.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Patterns of alcohol consumption among individuals with alcohol use disorder during the COVID-19 pandemic and lockdowns in Germany

Objective: To examine whether lockdown measures are associated with AC and consumption-related temporal and psychological within-person mechanisms. Design, setting, and participants: This quantitative, intensive, longitudinal cohort study recruited 1743 participants from 3 sites from February 20, 2020, to February 28, 2021. Data were provided before and within the second lockdown of the COVID-19 pandemic in Germany: before lockdown (October 2 to November 1, 2020); light lockdown (November 2 to December 15, 2020); and hard lockdown (December 16, 2020, to February 28, 2021). Main outcomes and measures: Daily ratings of AC (main outcome) captured during 3 lockdown phases (main variable) and temporal (weekends and holidays) and psychological (social isolation and drinking intention) correlates. Results: Of the 1743 screened participants, 189 (119 [63.0%] male; median [IQR] age, 37 [27.5-52.0] years) with at least 2 alcohol use disorder (AUD) criteria according to the Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) yet without the need for medically supervised alcohol withdrawal were included. These individuals provided 14 694 smartphone ratings from October 2020 through February 2021. Multilevel modeling revealed significantly higher AC (grams of alcohol per day) on weekend days vs weekdays (β = 11.39; 95% CI, 10.00-12.77; P < .001). Alcohol consumption was above the overall average on Christmas (β = 26.82; 95% CI, 21.87-31.77; P < .001) and New Year's Eve (β = 66.88; 95% CI, 59.22-74.54; P < .001). During the hard lockdown, perceived social isolation was significantly higher (β = 0.12; 95% CI, 0.06-0.15; P < .001), but AC was significantly lower (β = -5.45; 95% CI, -8.00 to -2.90; P = .001). Independent of lockdown, intention to drink less alcohol was associated with lower AC (β = -11.10; 95% CI, -13.63 to -8.58; P < .001). Notably, differences in AC between weekend and weekdays decreased both during the hard lockdown (β = -6.14; 95% CI, -9.96 to -2.31; P = .002) and in participants with severe AUD (β = -6.26; 95% CI, -10.18 to -2.34; P = .002). Conclusions and relevance: This 5-month cohort study found no immediate negative associations of lockdown measures with overall AC. Rather, weekend-weekday and holiday AC patterns exceeded lockdown effects. Differences in AC between weekend days and weekdays evinced that weekend drinking cycles decreased as a function of AUD severity and lockdown measures, indicating a potential mechanism of losing and regaining control. This finding suggests that temporal patterns and drinking intention constitute promising targets for prevention and intervention, even in high-risk individuals