Low level light therapy (LLLT) using light from red and near infrared LEDs or Lasers have been reported effective as noninvasive methods for reducing spot fat. A total of 55 subjects were randomly divided into test groups and control groups for abdominal fat reduction clinical trial using red and near infrared LED phototherapy devices. Red and near infrared light with irradiance of 10 mW/cm<sup>2</sup> were irradiated over the abdominal area to the test group for 30 minutes followed by 30 minutes of aerobic exercise, 3 times a week for 4 weeks. Control group used sham devices for 30 minutes and followed by 30 minutes of aerobic exercise. It is expected that red and near infrared LED phototherapy combined with aerobic exercise would be effective and safe for abdominal fat reduction without any side effects.
The effect of LED phototherapy on blood lactate level in the muscle was studied. A 450cm<sup>2</sup> large red and near infrared
LED pad with its irradiance of 10mW/cm<sup>2</sup> was applied for 10 minutes to brachial muscle and quadriceps muscle of thigh
to the participants before and after the Taekwondo contest. Blood samples from the participants were taken at 5 minutes
after the competition and 10 minutes after the recovery. The test results showed that the LED therapy (LEDT) before and
after the competition had a significant effect on the decrease of blood lactate level of the participants.
Photoluminescenc eand electroluminescence of CaSiN<SUB>2</SUB>:Eu materials were investigted to develop a new phosphor for thin film electroluminescence (TFEL) device applications. Ca<SUB>3</SUB>N<SUB>2</SUB> and Si<SUB>3</SUB>N<SUB>4</SUB> powders were mixed to form CaSiN<SUB>2</SUB> hostmaterials and Eu was added as the luminescent center. The mixed powermatrials were cold pressed under the pressure of 1 Kg/cm<SUP>2</SUP> to make pellets, and fired at 1400 degrees Celsius for 2 hours under N<SUB>2</SUB>H<SUB>2</SUB> envrionemtn. Th ex-ry diffraction(CRD) patterns of synthesizd materals wer well matched with CaSiN<SUB>2</SUB> of joint committee for powder diffraction standards (JCPDS) csrad. When illuminated by ultravilet rays, th enew phosphors emitted very bright red ligh of peak wav lenegth centered at 620 nm. Th TFEL devices with CaSiN<SUB>2</SUB>:Eu phosphor layser swre grown by sputter depositonof CaSiN<SUB>2</SUB>:Eu target. Red light emission was observed when the peak amplitude of the applied voltge exceeded 116 V.l The luminance was shown to increase sharply withth increase of the applied voltage. The maximum luminance was 1.62 Cd/m<SUP>2</SUP> at the applied peak voltage of 276 V. The red emission from CaSiN<SUB>2</SUB>:Eu TFEL device seems to result from electronic transition of Eu<SUP>3+</SUP> ions.The emission spectra of TFEl devices matchwell withth ephotoluminescence spectra of CaSiN<SUB>2</SUB>:Ey powders. The new devices structure and fabrication processes for the iimprovement of emission intenityof CaSiN<SUB>2</SUB>:Eu TFEl devices ar under investigation.