What exactly are spinners fidget?
Is hot new toy dangerous, or beneficial to kids? Hand spinner fidget have exploded in popularity, leaving many parents to ask: What is a spinner fidget? And so are they harmful to my children?
2017's the popular new toy is most popular with middle and elementary school-aged kids. They are bright and vibrant plastic or metal devices that fit in the palm of the hand and include a ball bearing that allows one to bend.As the name implies, spinner toy may be marketed as "stress relievers" for kids (and grownups) to soften with, and may supposedly help with ADHD or autism.
They could spin on a table like a dreidel or at your hand, developing a mesmerizing irregular pattern; the goal among enthusiasts is often to see who can spin it to the longest.Where to locate fidget hand spinner. Because of this, they are sometimes tough to discover.If you're fortunate, you can discover the coaster-sized gadgets to get as inexpensive as $1 on eBay and other sites, or even $ 5 at national chains such as Five Below.
Amazon.com has a bunch in the $8 to $18 range, but some high-end shops actually sell versions for up to $1,000.According to PennLive.com, though, many stores are fighting to maintain them at the stock. A Five Below at Pennsylvania sees them fly off the shelves; about a single Saturday, 200 hand spinner fidget toys were gone in less than 2 hours of availability."It's the hottest thing," store manager Andy Chelednik told that the book.
"It's only picked up with everyone for a few reason"Because of this, some parents are driving from store to store to get the toys, placing names on waiting lists or spending marked-up costs on reseller sites.Are there any benefits to employing spinner?
CNN reports that the devices were initially made to help students with eye disorders such as ADD and ADHD. Experts say it can help children occupy their hands at their desk while focusing on school work; some therapists and counselors have also been encouraging their use.
"Promoting fidgeting is a frequent way of managing care management," Elaine Taylor-Klaus, co-founder of all ImpactADHD, which assists parents of kids with attention deficit disorders, told the news channel. "For some people [with ADHD], there's a demand for continuous stimulation," she states. "Exactly what a fidget permits some people -- maybe not all people -- together with ADHD to do would be to concentrate their attention on what they need to concentrate on since there's sort of a background motion that's occupying that need."
Monday, June 26, 2017
Monday, June 19, 2017
The basic PV or solar cell (for example: Goal Zero Nomad 20 ) typically produces only a small amount of power. To produce more power, solar cells (about 40) can be interconnected to form panels or modules. PV modules range in output from 10 to 300 Watts. If more power is needed, several modules can be installed on a building or at ground-level in a rack to form a PV array.
- A transparent top surface, usually glass
- An encapsulant -- usually thin sheets of ethyl vinyl acetate that hold together the top surface, solar cells, and rear surface
- A rear layer -- a thin polymer sheet, typically Tedlar, that prevents the ingress of water and gases
- A frame around the outer edge, typically aluminum.
Energy performance ratings for PV modules include the following:
- Peak Watt -- Measures the maximum power of a module under laboratory conditions of relatively high light level, favorable air mass, and low cell temperature. These conditions are not typical in the real world.
- Normal operating cell temperature -- Measures a module's nominal operating cell temperature after the module first equilibrates with a specified ambient temperature. It results in a lower Watt value than the peak-Watt rating, but it is probably more realistic.
- AMPM Standard -- Measures the performance of a solar module under more realistic operating conditions. It considers the whole day rather than "peak" sunshine hours, based on the description of a standard solar global-average day (or a practical global average) in terms of light levels, ambient temperature, and air mass.
Home Solar Electric System Arrays
For home solar electric systems, the most common array design uses flat-plate PV modules or panels. These panels can either be fixed in place or allowed to track the movement of the sun.
The simplest PV array consists of flat-plate PV modules in a fixed position. These are some advantages of fixed arrays:
- No moving parts
- No need for extra equipment
- A lightweight structure.
These features make them suitable for many locations, including most residential roofs. Because the panels are fixed in place, their orientation to the sun is usually at an angle that is less than optimal. Therefore, less energy per unit area of array is collected compared with that from a tracking array. This drawback, however, must be balanced against the higher cost of the tracking system.
Solar arrays are designed to provide specified amounts of electricity under certain conditions. The following factors are usually considered when determining array energy performance:
- Characterization of solar cell electrical performance
- Determination of degradation factors related to array design and assembly
- Conversion of environmental considerations into solar cell operating temperatures
- Calculation of array power output capability.
The amount of electricity required may be defined by any one or a combination of the following performance criteria:
- Power output -- power (Watts) available at the power regulator, specified either as peak power or average power produced during one day.
- Energy output -- the amount of energy (Watt-hour or Wh) produced during a certain period of time. The parameters are output per unit of array area (Wh/m²), output per unit of array mass (Wh/kg), and output per unit of array cost (Wh/$).
- Conversion efficiency -- defined as "energy output from array" ÷ "energy input from sun" × 100%.
This last parameter is often given as a power efficiency, equal to "power output from array" ÷ "power input from sun" × 100%. Power is typically given in units of Watts (W), and energy is typically in units of Wh, or the power in Watts supplied during an hour.
To ensure the consistency and quality of PV systems and increase consumer confidence in system performance, various groups -- such as the Institute of Electrical and Electronics Engineers (IEEE), the International Electrotechnical Commission (IEC), and the American Society for Testing and Materials (ASTM) -- are working on standards and performance criteria for PV systems.
Home Solar Electric Components
A typical home solar electric system consists of these components:
- Solar cells
- Modules or panels (which consist of solar cells)
- Arrays (which consist of modules)
- Balance-of-system parts.
The balance-of-system equipment required depends on whether the system is a stand-alone system, connected to the electric grid, or a hybrid system. Balance-of-system equipment can include:
- Mounting racks and hardware for the panels
- Wiring for electrical connections
- Power conditioning equipment, such as an inverter
- Batteries for electricity storage (optional)
- Stand-by gasoline electric generator.