• Title/Summary/Keyword: low intensity laser

Search Result 115, Processing Time 0.027 seconds

A Study on the Relationship between the Brain and the Pelvis

  • Jung, Jae Hun;Pi, Chien Mei;Ahn, Hun Mo
    • Journal of Korean Medical Ki-Gong Academy
    • /
    • v.18 no.1
    • /
    • pp.27-51
    • /
    • 2018
  • Objective : The purpose of this study is to examine the relationship between the brain and the pelvis. Methods : The relationship between the pelvis and the brain was searched in PubMed, and these searching studies were reviewed. Conclusions : 1. Urinary disorder is influenced by brain. 2. Brain is influenced by luteinizing hormone. 3. Pelvic floor muscles are influenced by brain. 4. Urological Chronic Pelvic Pain Syndrome(UCPPS) is influenced by brain. 5. Brain is influenced by the low intensity laser acupuncture stimulating thirteen ghost acupoints(includes CV1).

Design of 808nm GRIN-SCH Quantum Dot Laser Diode (808nm GRIN-SCH 양자점 레이저 다이오드 설계)

  • Chan, Trevor;Son, Sung-Hun;Kim, Kyoung-Chan;Kim, Tae-Geun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2010.06a
    • /
    • pp.131-131
    • /
    • 2010
  • The power of semiconductor laser diodes has been limited primarily by the heating effects which occur at high optical intensities. The actual limiting event can take one of a number of forms such as. catastrophic optical damage or filamentation. A general approach to this problem is to design a heterostructure which creates a high powered output while maintaining low internal optical intensities. A graded index separate confinement heterostructure (GRIN-SCH) is one such structure that accomplishes the above task. Here, the active region is sandwiched between graded index layers where the index of refraction increases nearer to the active layer. This structure has been shown to yield a high efficiency due to the confinement of both the optical power and carriers, thereby reducing the optical intensity required to achieve higher powers. The optical confinement also reinforces the optical beam quality against high power effects. Quantum dots have long been a desirable option for laser diodes due to the enhanced optical properties associated with the zeroth dimensionality. In our work, we use PICS3D software created by Crosslight Software Inc. to simulate the performance of In0.67A10.33As/A10.2Ga0.8AsquantumdotsusedwithaGRIN-SCH. The simulation tools are used to optimize the GRIN-SCH structure for high efficiency and optical beam quality.

  • PDF

The Effect of Tail State on the Electrical and the Optical Properties in Amorphous IGZO (비정질 InGaZnO4 박막의 전기적, 광학적 특성간의 상관관계 연구)

  • Bae, Sung-Hwan;Yoo, Il-Hwan;Kang, Suk-Ill;Park, Chan
    • Journal of the Korean Ceramic Society
    • /
    • v.47 no.4
    • /
    • pp.329-332
    • /
    • 2010
  • In order to investigate the effect of tail state on the electrical and the optical properties in amorphous IGZO(a-IGZO), a-IGZO films were deposited at room temperature on fused silica substrats using pulsed laser deposition method. The laser pulse energy was used as the processing parameter. In-situ post annealing was carried out at $150^{\circ}C$ right after the film deposition. The $O_2$ partial pressure during the deposition and the post annealing was fixed to 10mTorr. The carrier mobility of the a-IGZO films had a range from 2 to $18\;cm^2/Vs$ at carrier concentrations greater than $10^{18}\;cm^{-3}$. As the laser energy density increased, the Hall mobility increased. And post annealing improved the Hall mobility, as well. The optical property was examined using the ultraviolet-visible spectroscopy. The a-IGZO films that have low Hall mobility exhibited stronger and broader absorption tails in >3.0 eV region. Post annealing reduced the intensity of the tail-like absorption. The absorption tail in a-IGZO films is an important factor which affects the electrical and the optical properties.

Temperature Dependent Terahertz Generation at Periodically Poled Stoichiometric Lithium Tantalate Crystal Using Femtosecond Laser Pulses

  • Yu, N.E.;Kang, C.;Yoo, H.K.;Jung, C.;Lee, Y.L.;Kee, C.S.;Ko, D.K.;Lee, J.
    • Journal of the Optical Society of Korea
    • /
    • v.12 no.3
    • /
    • pp.200-204
    • /
    • 2008
  • Coherent tunable terahertz generation was demonstrated in periodically poled stoichiometric lithium tantalate crystal via difference frequency generation of femtosecond laser pulses. Simultaneous forward and backward terahertz radiations were obtained around 1.35 and 0.63 THz, respectively at low temperature. By cooling the crystal to reduce losses caused by phonon absorptions, the generated THz bandwidth was as narrow as 23GHz at the center frequency of 0.63 THz. The measurement result of temperature-dependent showed gradual intensity increase of the generated terahertz pulse and red shift of the center frequency as the temperature decrease from 291 to 143 K, but insignificant reduction of the spectral bandwidth. Furthermore, the stoichiometric crystal was very suitable for the suppression of THz loss at low temperature compared to the congruent $LiNbO_3$ crystal.

Effects of Ultrasound, Laser and Exercises on Temporomandibular Joint Pain and Trismus Following Head and Neck Cancer

  • Elgohary, Hany Mohamed;Eladl, Hadaya Mosaad;Soliman, Ashraf Hassan;Soliman, Elsadat Saad
    • Annals of Rehabilitation Medicine
    • /
    • v.42 no.6
    • /
    • pp.846-853
    • /
    • 2018
  • Objective To compare the effects of low intensity ultrasound (LIUS), traditional exercise therapy (TET), low level laser therapy (LLLT) and TET on temporomandibular joint (TMJ) pain and trismus following recovery from head and neck cancer (HNC). Methods Sixty participants following, who had experienced HNC, were randomly allocated to three groups of 20 people each. Each group received different therapy. Group A received LIUS and TET; group B received LLLT and TET; while group C received TET. All 60 participants were evaluated under the visual analog scale (VAS), the University of Washington Quality of Life questionnaire (UW-QOL) and the Vernier caliper scale (VCS) at the beginning of the therapies and after 4 weeks. Results ANOVA test revealed significant improvements across all three groups with outcomes of p<0.05. The results of the UW-QOL questionnaire showed a significant difference between groups A, B and C in favor of group A (p<0.05). The VAS results showed a more improvement in group A as compared to group B (p<0.05), while there was no statistical difference between groups B and C (p>0.05). The VCS results showed more improvement for the individuals in group B as compared to those in group C (p<0.05), while there was minimal difference between groups A and B (p>0.05). Conclusion The LIUS and TET are more effective than LLLT and/or TET in reducing TMJ pain and trismus following HNC.

Biophysical therapy and biostimulation in unfavorable bony circumstances: adjunctive therapies for osseointegration

  • Kim, Yong-Deok
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • v.38 no.4
    • /
    • pp.195-203
    • /
    • 2012
  • Dental implants using titanium have greatly advanced through the improvement of designs and surface treatments. Nonetheless, the anatomical limits and physiological changes of the patient are still regarded as obstacles in increasing the success rate of implants further, even with the enhancement of implant products. So there have been many efforts to overcome these limits. The intrinsic potential for bone regeneration can be stimulated through adjuvant treatments with the continuous improvement of implant properties, and this can play an important role in achieving optimum osseointegration toward peripheral bone tissue and securing ultimate long-term implant stability in standard surgical procedures. For this purpose, various chemical, biological, or biophysical measures were developed such as bone grafts, materials, pharmacological agents, growth factors, and bone formation proteins. The biophysical stimulation of bone union includes non-invasive and safe methods. In the beginning, it was developed as a method to enhance the healing of fractures, but later evolved into Pulsed Electromagnetic Field, Low-Intensity Pulsed Ultrasound, and Low-Level Laser Therapy. Their beneficial effects were confirmed in many studies. This study sought to examine bone-implant union and its latest trend as well as the biophysical stimulation method to enhance the union. In particular, this study suggested the enhancement of the function of cells and tissues under a disadvantageous bone metabolism environment through such adjunctive stimulation. This study is expected to serve as a treatment guideline for implant-bone union under unfavorable circumstances caused by systemic diseases hampering bone metabolism or the host environment.

Post annealing effect on the photoluminescence properties of ZnO thin films prepared by atomic layer epitaxy (Atomic Layer Epitaxy에 의해 제작된 ZnO 박막의 후열처리에 따른 발광특성 연구)

  • 신경철;임종민;강승모;이종무
    • Journal of the Korean Vacuum Society
    • /
    • v.13 no.3
    • /
    • pp.103-108
    • /
    • 2004
  • High-quality ZnO films were grown on sapphire (001) substrates by the atomic layer epitaxy (ALE) technique using DEZn as a Zinc precusor and $H_2O $ as an oxidant at both $170^{\circ}C$ and $400^{\circ}C$ which are in the ALE and the CVD process temperature ranges, respectively. The films were annealed in an oxygen atmosphere in the temperature range from 600 to 100$0^{\circ}C$ for an hour and then investigate photoluminescence (PL) properties using He-Cd laser. PL intensity tends to increases as the annealing temperature increase for both the annealed ZnO films grown at $170^{\circ}C$ and $400^{\circ}C$ , while PL did not nearly occur at the as-deposited ones. The PL intensity of the ZnO film grown at $400^{\circ}C$ is low after it is annealed at high temperature owing to a large number of Zn-Zn bonds although it has increased in the visible light wavelength region after annealing. In contrast the PL intensity has increased significant in the visible light region after annealing

A Study on Thermal Stability of Ga-doped ZnO Thin Films with a $TiO_2$ Barrier Layer

  • Park, On-Jeon;Song, Sang-Woo;Lee, Kyung-Ju;Roh, Ji-Hyung;Kim, Hwan-Sun;Moon, Byung-Moo
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2013.02a
    • /
    • pp.434-436
    • /
    • 2013
  • Ga-doped ZnO (GZO) was substitutes of the SnO2:F films on soda lime glass substrate in the photovoltaic devices such as CIGS, CdTe and DSSC due to good properties and low cost. However, it was reported that the electrical resistivity of GZO is unstable above $300^{\circ}C$ in air atmosphere. To improve thermal stability of GZO thin films at high temperature above $300^{\circ}C$ an $TiO_2$ thin film was deposited on the top of GZO thin films as a barrier layer by Pulsed Laser Deposition (PLD) method. $TiO_2$ thin films were deposited at various thicknesses from 25 nm to 100 nm. Subsequently, these films were annealed at temperature of $300^{\circ}C$, $400^{\circ}C$, $500^{\circ}C$ in air atmosphere for 20 min. The XRD measurement results showed all the films had a preferentially oriented ( 0 0 2 ) peak, and the intensity of ( 0 0 2 ) peak nearly did not change both GZO (300 nm) single layer and $TiO_2$ (50 nm)/GZO (300 nm) double layer. The resistivity of GZO (300 nm) single layer increased from $7.6{\times}10^{-4}{\Omega}m$ (RT) to $7.7{\times}10^{-2}{\Omega}m$ ($500^{\circ}C$). However, in the case of the $TiO_2$ (50 nm)/GZO (300 nm) double layer, resistivity showed small change from $7.9{\times}10^{-4}{\Omega}m$ (RT) to $5.2{\times}10^{-3}{\Omega}m$ ($500^{\circ}C$). Meanwhile, the average transmittance of all the films exceeded 80% in the visible spectrum, which suggests that these films will be suitable for photovoltaic devices.

  • PDF

Effects of Fiber Wall Thickness on Paper Properties Using CLSM (CLSM을 이용한 고해과정 중 섬유벽 두께 변화의 종이 특성 영향 분석)

  • 김서환;박종문;김철환
    • Journal of Korea Technical Association of The Pulp and Paper Industry
    • /
    • v.31 no.1
    • /
    • pp.39-45
    • /
    • 1999
  • Refining in papermaking plays an important role in changing fiber properties as well as paper properties. The major effects of refining on pulp fibers are internal and external fibrillation, fiber shortening, and fines formation. Many workers showed that internal fibrillation of the primary refining effects was most influential in improving paper properties. In particular, refining produces separation of fiber walls into several lamellae, thus causing fiber wall swelling with water penetration. This leads to the increase of fiber flexibility and of fiber-to-fiber contact during drying. If the fibers are very flexible, they will be drawn into close contact with each other by the force of surface tension as the water is removed during the drainage process and drying stages. In order to study the effect of fiber wall delamination on paper properties, cross-sectional image of fibers in a natural condition had to be generated without distortion. Finally, it was well recognized that confocal laser scanning microscope (CLSM) could be one of the most efficient tool for creating and quantifying fiber wall delamination in combination with image analysis technique. In this study, the CLSM could be used not only to observe morphological features of transverse views of swollen fibers refined under low and high intensity, but also to investigate the sequence of fiber wall delamination and fiber wall breakage. From the CLSM images, increasing the specific energy or refining decreased the degree of fiber collapse, fiber cross-sectional area, fiber wall thickness and lumen area. High intensity refining produced more external fibrillation.

  • PDF

Design of Black Plastics Classifier Using Data Information (데이터 정보를 이용한 흑색 플라스틱 분류기 설계)

  • Park, Sang-Beom;Oh, Sung-Kwun
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.67 no.4
    • /
    • pp.569-577
    • /
    • 2018
  • In this paper, with the aid of information which is included within data, preprocessing algorithm-based black plastic classifier is designed. The slope and area of spectrum obtained by using laser induced breakdown spectroscopy(LIBS) are analyzed for each material and its ensuing information is applied as the input data of the proposed classifier. The slope is represented by the rate of change of wavelength and intensity. Also, the area is calculated by the wavelength of the spectrum peak where the material property of chemical elements such as carbon and hydrogen appears. Using informations such as slope and area, input data of the proposed classifier is constructed. In the preprocessing part of the classifier, Principal Component Analysis(PCA) and fuzzy transform are used for dimensional reduction from high dimensional input variables to low dimensional input variables. Characteristic analysis of the materials as well as the processing speed of the classifier is improved. In the condition part, FCM clustering is applied and linear function is used as connection weight in the conclusion part. By means of Particle Swarm Optimization(PSO), parameters such as the number of clusters, fuzzification coefficient and the number of input variables are optimized. To demonstrate the superiority of classification performance, classification rate is compared by using WEKA 3.8 data mining software which contains various classifiers such as Naivebayes, SVM and Multilayer perceptron.