Color temperature
Color temperature is a characteristic of visible light that has important applications in photography, videography, publishing and other fields. The color temperature of a light source is determined by comparing its chromaticity with a theoretical, heated black-body radiator. The temperature (in kelvin) at which the heated black-body radiator matches the color of the light source is that source’s color temperature; for a black body source, it is directly related to Planck’s law.
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Thermal conductivity
“K value” redirects here. For the force constant of a spring, see Hooke’s law.
In physics, thermal conductivity, k, is the property of a material that indicates its ability to conduct heat. It is used primarily in Fourier’s Law for heat conduction.
It is defined as the quantity of heat, ?Q, transmitted during time ?t through a thickness L, in a direction normal to a surface of area A, due to a temperature difference ?T, under steady state conditions and when the heat transfer is dependent only on the temperature gradient.
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- thermal conductivity = heat flow rate × distance / (area × temperature difference)
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- Alternately, it can be thought of as a flux of heat (energy per unit area per unit time) divided by a temperature gradient (temperature difference per unit length)
Outdoor Cannabis cultivation
This article is about the method of cultivating Cannabis outdoors traditionally. Cannabis grown outdoors can be just as potent as its indoor counterpart if tended to properly.
Process
When cultivated outdoors, the chosen areas are those which receive twelve hours or more of sunlight in a given day. In North America, northern locations are preferred (Humboldt County, California, Québec and British Columbia being particularly notable), but southern locations (such as Maui, Hawaii) are also known to be good producers.
In instances where the local laws do not permit growing cannabis, cultivators may choose to grow in forests or rugged and rural areas where the local population are not likely to find the crop. Another technique is to grow cannabis in a crop that is larger and obscures the plants, such as maize. This is reported by the United States government to be common in the midwestern states. Bamboo and elderberry are also used as camouflage companion plants.
Some government organizations have claimed that in state and national parks, people have been injured by these “rebel farmers” protecting their crops, including a well documented developing problem with Mexican cartels growing cannabis in US national parks and forests.
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Cultivating Cannabis indoors
This article is about the normally illegal method of cultivating Cannabis indoors traditionally, growing the plants in a soil-like medium and adding fertilizer when the plants are given water. Cultivating marijuana indoors is more complicated and expensive than growing outdoors, but it allows the cultivator complete control over the growing environment. Cannabis grown outdoors can be just as potent as its indoor counterpart if tended to properly.
Lighting
Cannabis being cultivated under metal halide lamps. Depicted is vegetative growth and an extensive hydroponics setup.
The single most important factor for the indoor cultivator to consider is lighting. Since cultivation of cannabis is harshly punished in some areas, many cultivators must set up a hidden indoor grow room and provide artificial light. Additionally, outdoor cultivators usually start their clones or seedlings indoors, under artificial light. Lighting types include fluorescent, high-intensity discharge (HID) including metal halide (MH), high pressure sodium (HPS), and LED. Fluorescent lights have the advantage of coolness, and are gentle enough to use on seedlings and rooting clones. HID lamps are the most efficient, and are usually used between 250-1000 watts.
Training Methods For Cannabis
LIGHT BENDING
Light bending occurs when a plant grows at an angle toward the light. You may have noticed plants on the perimeter of your grow area bending toward the light to try and get their share. If your plants bend too much they will eventually grow toward or even into another plant and block other plants from the light. Also, during flowering the buds will become heavy and may cause plants to fall over.
A simple way to avoid light bending in an indoor grow environment, is to simply switch your plants around. If a plant leans too much in one direction, then move it toward the middle of the grow space or turn the plant around. It only takes a day or two for the plant to straighten. If your plants can’t be easily moved, as is the case with hydroponic setups and outdoor gardens, then you may have to tie your plants so they don’t bend.
If you are growing outdoors and have a major problem with light bending you may have to cut away surrounding foliage to allow more light to reach your plants. If this is not possible, try using thread and small stakes, such as bamboo, to keep your plants upright. Remember: if your plants are bending they are trying to tell you that they need more direct light.
PRUNING FOR YIELD
Pruning is the action of manipulating the number of node regions (potential bud sites) that your plant creates and has nothing to do with the thinning process. Cutting a plant at the stem will automatically result in Hopping’. For this reason, plants that are thinned via cutting will end up growing more than one top cola. Topping is discussed in the next section. This section covers pruning to increase yield.
By using stakes you can also control and separate branch growth after pruning.
Man charged after pot grow house raid
Melbourne police have dismantled a grow house and put a man in jail on charges of cultivating marijuana.
The city’s Special Operations Unit received an anonymous complaint that there was drug activity at 1219 Carissa Place, off Pineapple Avenue. Members of the unit got a search warrant and raided the house around 8 p.m. Wednesday.
Inside, they found three rooms set up for growing pot, with grow lamps and climate control systems. One room had 48 medium-sized marijuana plants, police said.
Bust nets 171 marijuana plants; a ‘growing’ trend
MARION OAKS - Marion County sheriff’s deputies dismantled a marijuana grow house Thursday night containing 171 marijuana plants with an estimated street value of approximately $200,000, and arrested two of three men seen fleeing the area.
The third man, who reportedly was seen discarding a .38-caliber revolver, managed to escape, according to a Sheriff’s Office report.
Two of the men - Jose Perez, 59, of Green Acres, and Eliezer Lopez, 25, of West Palm Beach - were arrested on charges of cultivating marijuana, possession of drug paraphernalia and resisting arrest without violence, according to the Sheriff’s Office.
Officials with the High Intensity Drug Trafficking Agency, who are familiar with the case, said Perez and Lopez are from Cuba. Since the beginning of the year, they said, local drug agents have seen not only a significant increase in marijuana grow houses, but also those arrested increasingly have moved from South Florida to Central Florida.
Spectrum
A spectrum (plural spectra or spectrums) is a condition that is not limited to a specific set of values but can vary infinitely within a continuum. The word saw its first scientific use within the field of optics to describe the rainbow of colors in visible light when separated using a prism; it has since been applied by analogy to many fields. Thus one might talk about the spectrum of political opinion, or the spectrum of activity of a drug, or the autism spectrum. In these uses, values within a spectrum are not necessarily precisely defined numbers as in optics; exact values within the spectrum are not precisely quantifiable. Such use implies a broad range of conditions or behaviors grouped together and studied under a single title for ease of discussion.
In most modern usages of spectrum there is a unifying theme between extremes at either end. Some older usages of the word did not have a unifying theme, but they led to modern ones through a sequence of events set out below. Modern usages in mathematics did evolve from a unifying theme, but this may be difficult to recognize.
Color-rendering index
The color-rendering index (CRI) (sometimes called color rendition index), is a measure of the ability of a light source to reproduce the colors of various objects being lit by the source. It is a method devised by the International Commission on Illumination (CIE). The best possible rendition of colors is specified by a CRI of one hundred, while the very poorest rendition is specified by a CRI of zero. For a source like a low-pressure sodium vapor lamp, which is monochromatic, the CRI is nearly zero, but for a source like an incandescent light bulb, which emits essentially black body radiation, it is nearly one hundred. The CRI is measured by comparing the color rendering of the test source to that of a “perfect” source which is generally a black body radiator, except for sources with color temperatures above 5000K, in which case a simulated daylight (e.g. D65) is used. For example, a standard “cool white” fluorescent lamp will have a CRI near 63. Newer “triphosphor” fluorescent lamps often claim a CRI of 80 to 90.
Voltage spikes
In electrical engineering, spikes are fast, short duration electrical transients in voltage (voltage spikes), current (current spike), or transferred energy (energy spikes) in an electrical circuit.
Fast, short duration electrical transients (overvoltages) in the electric potential of a circuit are typically caused by
- lightning strikes
- power outages
- tripped circuit breakers
- short circuits
- power transitions in other large equipment on the same power line
- malfunctions caused by the power company
- electromagnetic pulses (EMP) with electromagnetic energy distributed typically up to the 100 kHz and 1 MHz frequency range.
- Inductive spikes
