Evaluating the Effect of Low Power Diode Laser 806 nm on the Healing of Unilateral Cleft Lip Scar: An Open-Label Comparative Study

Objective To investigate the effect of laser bio-modulation irradiation therapy on the scar after surgical correction of unilateral cleft lip. Design a comparative, open-label study. Setting we conducted the study in a university based tertiary hospital that recruited early wound healers of unilateral cleft lip correction. Patients Eighty patients were divided into two groups: In study's group, patients undergo laser bio-modulation irradiation (n = 60); in the control group, patients were followed-up without intervention (n = 20). Intervention In the study's group, patients underwent low-power diode Laser with wavelength of 806 nm and power of 100 mw. Main outcome The change in the scar of cleft lip patients, which was assessed by clinical examination and ultrasound. Results The median pigmentation score was significantly lower in the laser group (median = 1; IQR = 1–2) than the control group (median 2; IQR 1–3), with p-value of <0.001. Likewise, the median height score was significantly lower in the laser group (median = 1; IQR = 1–1) than the control group (median 1.5; IQR 1.5–2), with p-value of 0.001. The median pliability score was significantly lower in the laser group (median = 1; IQR = 1–1) than the control group (median 2.5; IQR 1–3), with p-value of <0.001. Finally, the median vascularity score was significantly lower in the laser group (median = 1; IQR = 1–1) than the control group (median 1.5; IQR 1–2), with p-value of <0.001. Conclusion laser bio-modulation irradiation therapy demonstrates a potential efficacy in managing the hypertrophic scars after surgical repair of unilateral cleft lip.

Effect of Shell Temperature on Thermal Resistance and Junction Temperature for Power Diode

Accurate measurement of junction temperature can avoid thermal failure of diode. During aging test, junction temperature should be indirectly calculated by testing its thermal resistance. In this paper, junction-to-case thermal resistance (Rthjc) of XX diode is tested by T3ster based on transient dual interface method. Its Rthjc is about 1.23K/W at 25°C and contains PN junction thermal resistance, metal shell thermal resistance and Sn-based solder thermal resistance, respectively. These three types of thermal resistance decrease in order. Effect of shell temperature on junction temperature and Rthjc is then discussed. As shell temperature increases, temperature variation of PN junction before and after heating and corresponding thermal resistance Rthjc both increase.

Dirac-Source Diode with Sub-unity Ideality Factor

An increase in power consumption necessitates a low-power circuit technology to extend Moore’s law. Low-power transistors, such as tunnel field-effect transistors (TFETs)1-5, negative-capacitance field-effect transistors (NC-FETs)6, and Dirac-source field-effect transistors (DS-FETs)7-10, have been realised to break the thermionic limit of the subthreshold swing (SS). However, a low-power diode rectifier, which breaks the thermionic limit of an ideality factor (η) of 1 at room temperature, has not been proposed yet. In this study, we have realised a DS diode, which exhibits a steep-slope characteristic curve, by utilising the linear density of states (DOSs) of graphene7. For the developed DS diode, η < 1 for more than two decades of drain current with a minimum value of 0.8, and the rectifying ratio is large (> 105). The realisation of a DS diode paves the way for the development of low-power electronic circuits.

Optimization of Process Conditions for Additive Manufacturing Technology Combining High-Power Diode Laser and Hot Wire

A high-efficiency additive manufacturing technology that combines a high-power diode laser with a large-rectangle spot (beam width of 11 mm) and a hot-wire system was developed. The hot-wire system can generate Jo ule heat by wire current and heat a filler to its melting point independently from the main heat source of a high-power diode laser. A simple calculation method to derive the appropriate hot-wire current of Z3321-YS308L was proposed with verification by hot-wire feeding experiments without laser irradiation at various wire currents. The effect of process parameters, such as laser power, process speed, and the wire feeding rate (wire feeding speed/process speed) on bead characteristics was investigated by cross-sectional evaluations on three-layer depositions. High-speed imaging observations of wire melting and molten pool formation showed that the energy density input and the wire feeding rate were dominant parameters in terms of bead formation and hot-wire feeding stability. A 50-mm-high, 8-mm-wide, and 250-mm-long sample was fabricated by using appropriate process conditions, and tensile tests were performed by using a sub-sample from the large sample.