THE MICRO-CLIMATE OF FRUIT TREES: I. LIGHT MEASUREMENTS WITH URANYL OXALATE ACTINOMETERS

1963 ◽  
Vol 43 (4) ◽  
pp. 561-568 ◽  
Author(s):  
Don R. Heinicke
Keyword(s):  
Light Intensity ◽  
Oxalic Acid ◽  
Linear Relationship ◽  
Potassium Permanganate ◽  
Fruit Trees ◽  
Similar Relationship ◽  
Measuring Device ◽  
Uranyl Oxalate ◽  
Climate Studies

A light meter using uranyl oxalate actinometry has been developed for use in studies of tree micro-climate. The method is based on the photo-destruction of oxalic acid in the presence of uranyl sulphate. The total amount of oxalic acid destroyed is determined by titration with deci-normal potassium permanganate. A linear relationship between the actinometer readings and gm. cal. day−1 cm.−2, as recorded by an Eppley pyrheliometer, was shown on bright days. A similar relationship was shown with time of exposure at a fixed light intensity. In micro-climate studies many readings of integrated light values can be taken with this inexpensive light measuring device.

Influence of Light on Fruit Set of French Hybrid Grapes

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 510f-511 ◽  
Author(s):  
D.C. Ferree ◽  
S.J. McArtney ◽  
D.M. Scurlock
Keyword(s):  
Light Intensity ◽  
Linear Relationship ◽  
Fruit Set ◽  
Light Level ◽  
Fruit Color ◽  
Soluble Solids ◽  
Hue Angle ◽  
Reduced Light ◽  
Negative Linear Relationship ◽  
Grape Cultivars

Four French–American hybrid grape cultivars grown in a greenhouse were subjected to 5 days of 80% shade at four different times around bloom. Fruit set of `Seyval' was reduced by shade imposed before, during, or immediately after bloom. `Vidal' and `Chambourcin' were less sensitive, with fruit set reduced only by shade at bloom. Shade had little effect on fruit set of `DeChaunac'. In a second study, `Chambourcin' vines were exposed to ambient, ambient plus supplemental lights, and 30%, 50%, or 80% shade for 5 weeks beginning just prior to bloom. Fruit set was positively related to light intensity. At harvest, soluble solids, pH, and hue angle had a negative linear relationship to light level. Fruit color developed earliest and most rapidly with the reduced light treatments applied at bloom. Cluster weight was positively related to light intensity.

scholarly journals The Effects of Day Length and Light Intensity on Tile Growth of Barley

1969 ◽  
Vol 22 (1) ◽  
pp. 53 ◽  
Author(s):  
D Aspinall
Keyword(s):  
Light Intensity ◽  
Linear Relationship ◽  
Light Source ◽  
Blue Light ◽  
Floral Development ◽  
Red Light ◽  
Day Length

The acceleration of flowering in barley due to the inclusion of incandescent illumination in the light source has been shown to be due to the far�red content of the light. A linear relationship between floral development and intensity of far�red light in a 16�hr photoperiod has been established with the cultivar CI5611. Barley appears to be relatively unresponsive to blue light, however.

scholarly journals Isotopic Fractionation of NBS Oxalic 14C Standard and Its Effect On Calculated Age of Materials

Radiocarbon ◽  
1980 ◽  
Vol 22 (2) ◽  
pp. 501-504 ◽  
Author(s):  
Victor A Nehmi
Keyword(s):  
Oxalic Acid ◽  
Isotopic Composition ◽  
Potassium Permanganate ◽  
Radiocarbon Dating ◽  
Isotopic Fractionation ◽  
Carbon 14

There is much controversy about the significance to radiocarbon dating of isotopic fractionation during the oxidation to CO2 of NBS oxalic acid, the carbon-14 dating standard. To check the effect of fractionation, 30 routine potassium permanganate oxidations of oxalic acid were performed. The isotopic composition of resulting CO2 was determined mass-spectrometrically. δ13C results ranged between —17.7 and —21.2, with an average of —18.9‰ wrt PDB. The effect of not applying an isotopic fractionation correction to NBS oxalic acid when performing age calculations is evaluated.

Anisotropic Temporal Integration in the Perception of Stereoscopic Corrugations

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 170-170 ◽  
Author(s):  
M R Hegarty ◽  
P B Hibbard ◽  
M F Bradshaw ◽  
B De Bruyn ◽  
A D Parton
Keyword(s):  
Linear Relationship ◽  
Stimulus Duration ◽  
Exposure Duration ◽  
Temporal Integration ◽  
Surface Orientation ◽  
Similar Relationship ◽  
Spatial Frequencies ◽  
Do So

Disparity sensitivity for horizontal depth corrugations increases with exposure duration for presentations of up to 1 s (Tyler, 1990 Vision Research30 1877 – 1895). To extend the work of Parton et al (1996 Perception25 67) we investigated whether differences existed in the effects of exposure for corrugations at different orientations. Disparity thresholds were measured for horizontal, vertical, and diagonal gratings with spatial frequencies ranging between 0.1 cycle deg−1 and 0.8 cycle deg−1, as a function of stimulus duration. Stimuli were presented for exposures of between 50 ms and 32 s, and were followed by a random disparity mask, which served the important function of disrupting further processing of stimulus disparity. Thresholds were greatest for vertical gratings. This effect was particularly pronounced for the lowest frequencies. In all conditions, disparity sensitivity improved as exposure duration increased, and continued to do so for all durations tested. For vertical and diagonal gratings, log - log plots of threshold against time showed a linear relationship with a slope of −1 up to 1.0 s, after which time improvements in sensitivity reduced. Horizontal gratings showed a similar relationship, but with thresholds ceasing to decrease significantly after 0.5 s. Temporal integration limits differ with surface orientation, and represent another important difference in our ability to detect and encode depth in stereoscopic surfaces.

scholarly journals Photosynthesis in Relation to Leaf Orientation and Light Interoeption

1964 ◽  
Vol 17 (3) ◽  
pp. 591 ◽  
Author(s):  
PE Kriedeman ◽  
TF Neales ◽  
DH Ashton
Keyword(s):  
Light Intensity ◽  
Photosynthetic Activity ◽  
Geometrical Optics ◽  
Angle Of Incidence ◽  
Similar Relationship ◽  
Photosynthetic Response ◽  
Leaf Orientation ◽  
Incoming Radiation

This paper examines the photosynthetic response of single attached leaves (of four different species) to an increasing angle of incidence (8) of incoming radiation. The intensity of light falling upon a leaf can be deduced from geometrical optics to be proportional to cos 8. The results reported here suggest that the photosynthetic. activity of leaves exposed to a limiting light intensity follows a similar relationship. Explanations of this empirically determined relationship are discussed.

scholarly journals The determination of organic matter in air

1887 ◽  
Vol 41 (246-250) ◽  
pp. 238-247 ◽  
Keyword(s):  
Organic Matter ◽  
Oxalic Acid ◽  
Potassium Permanganate ◽  
Water Analysis ◽  
Distilled Water ◽  
Dilute Solution ◽  
Single Determination ◽  
Time Required

The Only methods hitherto proposed for determining the amount of organic matter in air are the two devised by the late Dr. Angus Smith (“Air and Rain”). According to the first of these methods, a defi­nite quantity of the air to be examined is slowly bubbled through a dilute solution of potassium permanganate of known strength until it is fully or considerably bleached,' and in the latter ease the amount of undecomposed permanganate determined by oxalic acid. In the second method a known volume of air is bubbled through distilled water, and the latter examined for free and albuminoid ammonia by Wanklyn and Chapman’s process for water analysis. These methods are open to one or more of the following objec­tions :— 1. The time required for a single determination is very considerable , and recessarily varies with the amount of organic matter present.

scholarly journals PERANCANGAN ALAT UKUR INTENSITAS CAHAYA BERBASIS ARDUINO LEONARDO MENGGUNAKAN SENSOR LDR (Light Dependent Resistor)

2020 ◽  
Vol 16 (1) ◽  
pp. 1-13
Author(s):  
Simson Manik ◽  
Abdul Muis Muslimin ◽  
Aries A. Subgan
Keyword(s):  
Light Intensity ◽  
Comparative Data ◽  
Primary Data ◽  
Average Error ◽  
Measuring Device ◽  
Measuring Devices ◽  
Vertical Distance ◽  
Light Sensor ◽  
The Difference ◽  
Error Percentage

Lux meter is a device used to measure the intensity of light in an area. The purpose of this thesis is to design a light intensity measuring device using LDR components as a light sensor, comparing light intensity measuring devices made using LDR sensors and Arduino Leonardo based microcontrollers with standard tools. The data used in this study are primary data. The data obtained is then processed using MS. Excel. The type of light bulbs used are Philips CFL (Philips Essential) lamps, each lamp having a power of 5, 8, 11, 14, 18, 23, 27, 32, 35, and 50 watts with a luxmeter vertical distance of 1, 2 and 3 meters from the lamp. From the results of testing the tools and processing of comparative data between the Lux Meter Standard and the designed Lux ​​Meter obtained as follows: the vertical distance of the tool by 1 meter from the lamp produces an average error difference of 12,571 lx and the percentage of average errors the average is 8.77%, while for the vertical distance of the tool is 2 meters from the lamp the average error difference value is 2,358 lx and the average error percentage is 7.98%, and for the vertical tool distance is 3 meters from the lamp the difference in error value is an average of 0.92 lx and an average error percentage of 5.85%.

Sign in / Sign up

Export Citation Format

Share Document