Archive for June 2013

Blu-ray Disc

A single-Layer BD has storage capacity of 25GB, while a dual-la

Disc (also known as Blu-ray or BD) is an optical disc storage media
format. It is mainly used in high-definition video and data storage.
Blu-ray Disc has the same physical dimensions as a standard DVD or

single-Layer Blu-ray has storage capacity of 25GB, while a dual-layer
BD can store up to 50GB of data. As the name suggests, a blue-violet
laser is used to write data on a Blu-ray disk, unlike the traditional
method wherein red laser employed to store data on DVDs.

Blu-ray disk can hold 9-hour high definition video and
standard-definition (SD) video that can run 23 hours, on a 50GB disk.
The BD-ROM movies will require a rate of MBPS for data transfer, so
the expected speed is 2x (72 Mbps). There is also a scope for having
much higher speed because of the larger numerical aperture (NA)
adopted by the BD. It implies that a Blu-ray disk will need less
recording power and lower disk rotation speed vis-à-vis
conventional DVDs and HD DVDs. The sole limiting factor for blu-ray
is the capacity of the hardware.

storage capacity of Blu-ray disk (BDs) is five times that of
conventional DVDs. BDs supports NPEG-2, MPEG-4 AVC and SMPTE VC-1
formats (codecs).

Disc uses a “blue” (technically violet) laser operating at
a wavelength of 405 nm to read and write data. Conventional DVDs and
CDs use red and near infrared lasers at 650 nm and 780 nm

blue-violet laser’s shorter wavelength makes it possible to store
more information on a 12 cm CD/DVD sized disc. The minimum “spot
size” on which a laser can be focused is limited by diffraction,
and depends on the wavelength of the light and the numerical aperture
of the lens used to focus it. By decreasing the wavelength,
increasing the numerical aperture from 0.60 to 0.85 and making the
cover layer thinner to avoid unwanted optical effects, the laser beam
can be focused to a smaller spot. This allows more information to be
stored in the same area. For Blu-ray Disc, the spot size is 580 nm In
addition to the optical improvements; Blu-ray Discs feature
improvements in data encoding that further increase the capacity.

Engineering Services

DC Power Connectors

[WATCH]: Back Pain Relief Exercises | Workout for Lower Back Pain : Pelvic Lift Video

Rating: 5
More back pain relief exercises information at To get rid of your back pain, you need to do some workout for your…

[WATCH]: My Life is a Living Hell… Herniated Disc & Back Surgery

Rating: 4
I don’t talk about this much, let alone with my YouTube audience, but I’ve been in unspeakable pain for a long time now. Close friends and family are aware, …

[WATCH]: sciatica stretch

Rating: 4 – Sciatica stretches can often eliminate your sciatic pain fast, this simple scia…

Back surgery for pack pain? Think again

studied a group of Ohio residents who were out of work due to back pain. All
patients were part of the Ohio Worker’s Compensation program and their medical
files were available to researchers. They examined 725 patients with lumbar
fusion compared to workers in the program who had chronic lower back pain
diagnoses but who had not received a lumbar fushion surgery.

examined the state of the workers two years after either the injury itself (if
the patient did not have surgery) or two years after the lumbar fushion
surgery. Their findings should make you think twice about a surgical solution
to back pain.

researchers found that those without surgery were more likely to return to
work. After two years, 26% of those who had surgery had returned to work,
compared to 67% of those who did not have surgery. Of those with surgery, 27%
received a second surgery. The surgical patients were also
more likely to be using pain medication at the end of the two-year period. Some
patients continued using pain medications daily (41% of the surgery patients);
76% of the surgery patients continued on pain medication.

studied the records of 1450 patients in Ohio who were diagnosed with  disc degeneration, disc herniation or
radiculopathy. After two years, 26% of patients who had surgery returned to
work, compared to 67 percent of those who did not have surgery. Among those who
had back surgery, there was an increase of 41% in the use of painkillers,
particularly opiates.

Patients who
sought pain relief with surgery ended up on pain relieving drugs and were less
likely to return to work than non-surgery patients. Read the abstract from the study.

For non-surgical
back pain relief, people turn toward chiropractics, acupuncture, physical
therapy, exercise, and anti-inflammatory diets. Back pain is complex and we
recommend a patient use every avenue at his or her disposal to reduce pain.
However, one treatment that has been extremely effective is spinal decompression therapy, offered by chiropractors. It is likely to give
you a great deal of relief, particularly when combined with a life style that
supports the health of your back.

Mike Gramsby is back pain-free and living in central California with his favorite Visalia chiropractor?and Porterville chiropractor.