Virtual memory is a common part of most operating systems on desktop computers. It has become so common because it provides a big benefit for users at a very low cost.In this article, you will learn exactly what virtual memory is, what your computer uses it for and how to configure it on your own machine to achieve optimal performance.
Most computers today have something like 32 or 64 megabytes of RAM available for the CPU to use (see How RAM Works for details on RAM). Unfortunately, that amount of RAM is not enough to run all of the programs that most users expect to run at once.
For example, if you load the operating system, an e-mail program, a Web browser and word processor into RAM simultaneously, 32 megabytes is not enough to hold it all.
If there were no such thing as virtual memory, then once you filled up the available RAM your computer would have to say, "Sorry, you can not load any more applications.Please close another application to load a new one." With virtual memory, what the computer can do is look at RAM for areas that have not been used recently and copy them onto the hard disk. This frees up space in RAM to load the new application.
The area of the hard disk that stores the RAM image is called a page file. It holds pages of RAM on the hard disk, and the operating system moves data back and forth between the page file and RAM. On a Windows machine, page files have a .SWP extension.
Because this copying happens automatically, you don't even know it is happening, and it makes your computer feel like is has unlimited RAM space even though it only has 32 megabytes installed. Because hard disk space is so much cheaper than RAM chips, it also has a nice economic benefit.
The read/write speed of a hard drive is much slower than RAM, and the technology of a hard drive is not geared toward accessing small pieces of data at a time. If your system has to rely too heavily on virtual memory, you will notice a significant performance drop.
The key is to have enough RAM to handle everything you tend to work on simultaneously -- then, the only time you "feel" the slowness of virtual memory is is when there's a slight pause when you're changing tasks. When that's the case, virtual memory is perfect.
When it is not the case, the operating system has to constantly swap information back and forth between RAM and the hard disk. This is called thrashing, and it can make your computer feel incredibly slow.
The area of the hard disk that stores the RAM image is called a page file. It holds pages of RAM on the hard disk, and the operating system moves data back and forth between the page file and RAM. On a Windows machine, page files have a .SWP extension.
Sunday, January 18, 2009
How Gas Prices Work
In May 2008, average gas prices in the United States approached, and in some places passed, $4.00 a gallon, shattering records. But this was nothing new to American consumers. May was a month of records that broke one after another, and that came on the heels of months of rising prices.Gasoline is the bloodline that keeps America moving, and tracking gas prices can feel like a roller coaster ride. They're down a little one month, up the next, and then they shoot up more than 50 percent in a year. Plus, they're different depending on where you look. Other countries -- and even other states and cities -- can have very different gas prices from your local Gas-N-Go. To the average person, it probably seems as though there's little rhyme or reason to how gas prices are determined. In this article, we will look at the forces that impact the price of gas at the pump, and we'll find out where your gas money actually goes.Americans have an insatiable thirst for gasoline. Just look at the amount of traffic on roads and highways, and you'll see that a severe gas shortage would practically cripple the United States. Americans drive nearly 3 trillion miles per year, according to the Motor and Equipment Manufacturer's Association [source: MEMA]. That's about 820 trips from the sun to Pluto and back.The United States consumes about 20 million barrels of oil products per day (bbl/d), according to the Department of Energy [source: DOE]. Of that, almost half is used for motor gasoline. The rest is used for distillate fuel oil, jet fuel, residual fuel and other oils. Each barrel of oil contains 42 gallons (159 L), which yields 19 to 20 gallons (75 L) of gasoline. So, in the United States, something like 178 million gallons of gasoline is consumed every day.Typically, the demand for gas spikes during the summer, when lots of people go on vacation. Holidays like Memorial Day and the Fourth of July create logjams of tourist traffic during the summer. This high demand usually translates into higher gasoline prices. Cleaner-burning summer-grade fuels, which are more expensive to produce, can increase the price as well, but prices don't always go up in summer. For instance, while gas prices soared 31 cents in April and early May of 2001, reaching $1.71 per gallon (which seems inexpensive compared to today's prices), prices actually declined during the 2001 summer.In 2004, prices continued to rise past the end of the summer travel season for a variety of reasons, including several hurricanes and an increase in the price of crude oil. And in 2005, Hurricane Katrina (along with a sizable increase in crude oil prices) pushed prices to $3.07 per gallon on September 5. Prices settled down somewhat in November and December of 2005. But now the numbers are among the highest they've ever been, only recently dipping back below the $4.00 mark after a month of average prices at $4.06 for a gallon of regular gas in July 2008 [source: EPA]. It seems the record high prices encouraged people to drive less, which in turn drove down demand and subsequently, prices. Whether the price drop is the beginning of a trend remains to be seen.Price increases generally occur when the world crude-oil market tightens and lowers inventories. We will discuss who controls the crude-oil market later. Also, growing demand can sometimes outpace refinery capacity. In the spring, refineries perform maintenance, which can place a pinch on the gasoline market. By the end of May, refineries are usually back to full capacity.
What is Ecstasy
What is Ecstasy? - Ecstasy is one of the most dangerous drugs threatening young people today. Called MDMA (3-4-Methylenedioxymethamphetamine) by scientists, it is a synthetic chemical that can be derived from an essential oil of the sassafras tree. MDMA is also one of the easiest illegal drugs to obtain. Its effects are similar to those of amphetamines and hallucinogens. Distributed almost anywhere, it has become very popular at social events like raves, hip hop parties, concerts, etc. frequented by both adults and youth. While not all “event” attendees use Ecstasy, the drug often makes the circuit of these parties and can set up dangerous circumstances that can affect everyone there.
Street Names: E, Adam, Roll, Bean, X and XTC
· Clarity, Essence, Stacy, Lover’s Speed, Eve
· Form: Pills - usually white, yellow or brown
· Size, shape and design vary
· Pills are often branded with designer .
Legal or Not? - First developed as an appetite suppressant in 1914, MDMA was used as a psychotherapeutic tool and also started to become available on the street In the late ‘70s and early ‘80s. It wasn’t until 1985 that Ecstasy was made illegal. It is classified as a “Schedule 1” controlled substance along with other narcotics like heroin, cocaine, and LSD. Penalties for possession, delivery, and manufacturing of the drug can include fines as high as $100,000 and up to 99 years or life in prison, depending on the amount seized.
Dangerous Impurities - One reason Ecstasy can be especially dangerous is the lack of content control. Ingredients are hard to get and manufacturers of the drug often use substitutes, mixing other harmful additives with the already dangerous mix. This practice is so common that “drug test kits” are often sold with the drug so users can test for purity. Because of the uncertainties about the drug sources, pharmacological agents, chemicals used to manufacture them, and possible contaminants, it is difficult to measure the toxicity, consequences and symptoms that might be expected.
How is it Used? - Ecstasy is usually taken in pill form and swallowed and it can also be injected Some users have been known to crush and snort the resulting powder. Others insert the pill into the anus where it is absorbed. This process is known as “shafting.”
How Does It Affect You? - Ecstasy is similar (in nature) to other amphetamines and hallucinogens. It speeds up the nervous system and acts as a mood enhancer. Also referred to as “the love drug”, Ecstasy often makes the user feel good, happy and relaxed - at least at first. Contrary to rumors, Ecstasy is not an aphrodisiac and can actually inhibit sexual performance.The taking of any drug affects people differently. Depending on size, weight, health, dosage and other drugs being used, the reaction can be mild or very severe. Anyone suffering from hypertension, heart disease, diabetes, epilepsy, mental illness or panic should avoid taking Ecstasy.
Common Side Effects -The following effects start within 20 minutes of taking E and can last for 4 - 6 hours or longer:
· Increased heart rate
· Increased body temperature
· Increased blood pressure
· Increased confidence
· Nausea
· Anxiety
· Feelings of well-being (happiness, love)
· Sweating
· Loss of appetite
Other Reported Effects - Taking higher doses of MDMA will not increase the good feelings. In fact higher dosages can cause convulsions, irrational behavior, and hallucinations. Users have reported having problems with insomnia, anxiety, paranoia, concentration and depression after taking the drug.
Overdose -Taking too much Ecstasy can result in:
· Extremely high body temperatures
· High blood pressure
· Hallucinations
· Fast Heartbeat
· Breathings problems
· Death
Death often results from harmful overheating (hyperthermia), or from drinking too much at one time (hyponatremia). Hyponatremia is a condition where excess fluid intake swells the brain resulting in coma. A third cause of death is stimulation. Over stimulation of the nervous system can result in heart attack or brain hemorrhage.
Warning Signs of Overdose
· Feeling hot or unwell
· Becoming confused, not able to talk properly
· Headache
· Vomiting
· Not Sweating
· Racing heart or pulse when resting
· Fainting or collapsing
· Loss of control over body movements
· Tremors
· Problems Urinating
Duration of Effects - An Ecstasy high can last from six to 24 hours but usually averages three to four hours. Some reactions have been reported to persist from one to 14 days after use.
Short Term Effects - Short-term effects include psychological difficulties (confusion, depression, sleep problems, craving, severe anxiety, and paranoia). These effects occur during use and can continue even weeks after use. Physical problems that can occur are muscle tension, involuntary teeth clenching, nausea, blurred vision, rapid eye movement, fever, chills or sweating.
Long Term Effects -Recent findings connect use of Ecstasy to memory loss. Use of Ecstasy depletes serotonin, a very important chemical in the brain which regulates mood, sleeping and eating habits, as well as, the thinking and behavior process, sexual function, and sensitivity to pain.
Herbal Ecstasy -Herbal Ecstasy is another form of MDMA that is composed of ephedrine (ma huang) or pseudoephedrine and caffeine from the kola nut. Also sold in tablet form, Herbal Ecstasy can cause permanent brain damage and death. Though not currently classified as a controlled substance, Herbal Ecstasy shares many of the same qualities and effects as MDMA. Also known as Cloud 9, Herbal Bliss, Ritual Spirit, Herbal X, GWM, Rave Energy, Ultimate Xphoria and X.
Drug Testing - Ecstasy can be detected up to four days in the urine.
Ecstasy and Anti-Depressants -People currently taking an MAOI should not use Ecstasy. MAOIs are most commonly found in prescription anti-depressants Nardil (phenelzine), Parnete (tranylcypromine), Marplan (isocarboxazid), Eldepryl (I-deprenyl), and Aurorex or Manerix (moclobermide). The same is true of the protease inhibitor Ritonavir.
Street Names: E, Adam, Roll, Bean, X and XTC
· Clarity, Essence, Stacy, Lover’s Speed, Eve
· Form: Pills - usually white, yellow or brown
· Size, shape and design vary
· Pills are often branded with designer .
Legal or Not? - First developed as an appetite suppressant in 1914, MDMA was used as a psychotherapeutic tool and also started to become available on the street In the late ‘70s and early ‘80s. It wasn’t until 1985 that Ecstasy was made illegal. It is classified as a “Schedule 1” controlled substance along with other narcotics like heroin, cocaine, and LSD. Penalties for possession, delivery, and manufacturing of the drug can include fines as high as $100,000 and up to 99 years or life in prison, depending on the amount seized.
Dangerous Impurities - One reason Ecstasy can be especially dangerous is the lack of content control. Ingredients are hard to get and manufacturers of the drug often use substitutes, mixing other harmful additives with the already dangerous mix. This practice is so common that “drug test kits” are often sold with the drug so users can test for purity. Because of the uncertainties about the drug sources, pharmacological agents, chemicals used to manufacture them, and possible contaminants, it is difficult to measure the toxicity, consequences and symptoms that might be expected.
How is it Used? - Ecstasy is usually taken in pill form and swallowed and it can also be injected Some users have been known to crush and snort the resulting powder. Others insert the pill into the anus where it is absorbed. This process is known as “shafting.”
How Does It Affect You? - Ecstasy is similar (in nature) to other amphetamines and hallucinogens. It speeds up the nervous system and acts as a mood enhancer. Also referred to as “the love drug”, Ecstasy often makes the user feel good, happy and relaxed - at least at first. Contrary to rumors, Ecstasy is not an aphrodisiac and can actually inhibit sexual performance.The taking of any drug affects people differently. Depending on size, weight, health, dosage and other drugs being used, the reaction can be mild or very severe. Anyone suffering from hypertension, heart disease, diabetes, epilepsy, mental illness or panic should avoid taking Ecstasy.
Common Side Effects -The following effects start within 20 minutes of taking E and can last for 4 - 6 hours or longer:
· Increased heart rate
· Increased body temperature
· Increased blood pressure
· Increased confidence
· Nausea
· Anxiety
· Feelings of well-being (happiness, love)
· Sweating
· Loss of appetite
Other Reported Effects - Taking higher doses of MDMA will not increase the good feelings. In fact higher dosages can cause convulsions, irrational behavior, and hallucinations. Users have reported having problems with insomnia, anxiety, paranoia, concentration and depression after taking the drug.
Overdose -Taking too much Ecstasy can result in:
· Extremely high body temperatures
· High blood pressure
· Hallucinations
· Fast Heartbeat
· Breathings problems
· Death
Death often results from harmful overheating (hyperthermia), or from drinking too much at one time (hyponatremia). Hyponatremia is a condition where excess fluid intake swells the brain resulting in coma. A third cause of death is stimulation. Over stimulation of the nervous system can result in heart attack or brain hemorrhage.
Warning Signs of Overdose
· Feeling hot or unwell
· Becoming confused, not able to talk properly
· Headache
· Vomiting
· Not Sweating
· Racing heart or pulse when resting
· Fainting or collapsing
· Loss of control over body movements
· Tremors
· Problems Urinating
Duration of Effects - An Ecstasy high can last from six to 24 hours but usually averages three to four hours. Some reactions have been reported to persist from one to 14 days after use.
Short Term Effects - Short-term effects include psychological difficulties (confusion, depression, sleep problems, craving, severe anxiety, and paranoia). These effects occur during use and can continue even weeks after use. Physical problems that can occur are muscle tension, involuntary teeth clenching, nausea, blurred vision, rapid eye movement, fever, chills or sweating.
Long Term Effects -Recent findings connect use of Ecstasy to memory loss. Use of Ecstasy depletes serotonin, a very important chemical in the brain which regulates mood, sleeping and eating habits, as well as, the thinking and behavior process, sexual function, and sensitivity to pain.
Herbal Ecstasy -Herbal Ecstasy is another form of MDMA that is composed of ephedrine (ma huang) or pseudoephedrine and caffeine from the kola nut. Also sold in tablet form, Herbal Ecstasy can cause permanent brain damage and death. Though not currently classified as a controlled substance, Herbal Ecstasy shares many of the same qualities and effects as MDMA. Also known as Cloud 9, Herbal Bliss, Ritual Spirit, Herbal X, GWM, Rave Energy, Ultimate Xphoria and X.
Drug Testing - Ecstasy can be detected up to four days in the urine.
Ecstasy and Anti-Depressants -People currently taking an MAOI should not use Ecstasy. MAOIs are most commonly found in prescription anti-depressants Nardil (phenelzine), Parnete (tranylcypromine), Marplan (isocarboxazid), Eldepryl (I-deprenyl), and Aurorex or Manerix (moclobermide). The same is true of the protease inhibitor Ritonavir.
StreetWorks
Fat Naked Girls, Botero Goes Parking Lot By Jacob Katel in StreetWorks
Jacob Katel
Donna Sdraiata, Fernando Botero
StreetWorks is usually a graffiti blog. Starting today, as long as I'm shooting, it'll document all forms of publicly displayed art, from the gutter to the gallery.With that in mind, this week's feature is the Gary Nader Sculpture Park featuring bronze work by Fernando Botero. The sculptures are lined up in the parking lot of the Gary Nader Fine Art gallery in Miami's Wynwood Art District.
Jacob Katel
Male Torso, Fernando Botero
According to Conrado de la Torre, Gary Nader representative, each Botero sculpture, all of which are bronze and made in a foundry in Pietrasanta, Italy, costs from 1 to 2 million dollars. They are all for sale and Art Basel is coming up, so get your view on before some rich collector hauls 'em out the parking lot and throws 'em in their living room.
Botero's works are world famous and can be found in Paris, China and Monte Carlo so take the opportunity to see them free while you got it. Also look out for Gary Nader Fine Art at this Saturday's Wynwood art walk when they unleash their Picasso's, Wifredo Lam's, and Frida Kahlo's for a free Latin American Modern and Contemporary Masters exhibition.
The sculpture park also features the unique carved-marble work of Pablo Atchugarry and a giant french fry looking sculpture by John Henry.
Want to know where to go? Here's a map:
The sculpture park is free and open to the public Monday - Saturday from 10 a.m. to 6 p.m.
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