- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
The qualification and training of laser/intense pulse light hair removal operators within South Africa
摘要： Background: Lasers and intense pulse light (IPL) sources are powerful devices that can cause skin burns, pigmentary changes, and scarring if used incorrectly. Adequate training is essential, and regulations are required to limit complications. Aims: The purpose was to investigate the qualifications and training obtained by laser hair removal operators in South Africa. Methods: Questionnaires were distributed and information gathered from owners/managers of laser clinics, suppliers of laser devices in South Africa, individuals in the workplace performing laser hair removal procedures, and accredited tertiary institutions. Results: A majority of clinic owners/managers (94.45%) felt that more emphasis should be placed on laser hair removal training at a tertiary level, and 66.67% outsource additional training provided by the manufacturer of laser devices. Based on the survey to manufacturers, 50% did not require any formal qualification as a minimum requirement, while 33.33% indicated laser hair removal training is incorporated at a NQF level 4 (National/Senior Certificate). The majority of individuals (68.89%) received training from tertiary institutions; however, they did not receive any practical training, and 60.87% felt the amount of training was insufficient. According to the survey sent to tertiary institutions in South Africa, only 27.78% offer laser hair removal training, and of these, 20% offer no practical training and 50% indicated that no practical examination is provided. Conclusions: There is a clear lack of training in laser hair removal in South Africa. The industry should have standard requirements in terms of minimum practical and theoretical hours with regards to the therapy.
关键词： training,intense pulse light,laser hair removal,laser complications
更新于2025-09-16 10:30:52
-
Machinability of titanium alloy through laser machining: material removal and surface roughness analysis
摘要： Laser milling is a competent precision process especially when the work material is hard-to-machine such as titanium alloys. While performing the laser milling, a slight change in one of the laser parameters results in an abrupt change in the machining outcomes. A close match between the designed and the machined geometries is the essence of precision machining. A precise control over the material removal rate per laser scan is highly desirable but difficult to achieve. The difficulty level becomes higher if high surface finish is desired alongside the precision machining. In this research, the objective was set to perform the laser milling on titanium alloy (Ti-6Al-4V) with 100% control over material removal rate (MRR) per laser scan and minimum surface roughness (SR). Influence of the five laser parameters (laser intensity, pulse frequency, scan speed, layer thickness, and track displacement) on MRR and SR has been deeply investigated. Significance of each laser parameter is evaluated through ANOVA. Mathematical models for both the responses are developed to estimate the resulting responses at any parametric setting. Models have also been validated through confirmatory tests. Optimization of laser parameters is of great importance to remove the material exactly equal to the desired depth with minimum surface roughness. Therefore, the optimized combinations of laser parameters have been proposed which ensure the conformance of 100% MRR and minimum surface roughness with composite desirability > 0.9. Confirmatory experiments revealed that the optimized parameters are capable to produce the laser milling results as per the models’ predicted results. Additionally, the microstructure of the subsequent layers below the milled area has also been examined and compared with the microstructure of the bulk Ti-6Al-4V. By the use of optimized parameters, microstructure of the sub-layers remains unchanged as compared with the microstructure of the base metal. No evidence has been found altering the microstructure of the sub-layers.
关键词： Laser milling,Titanium alloy,Mathematical model,Surface roughness (SR),Optimization,Material removal rate (MRR)
更新于2025-09-16 10:30:52
-
Recycling Oxacillin Residues from Environmental Waste into Graphene Quantum Dots
摘要： Of great concern are the residual antibiotics from dirt that can be found in farm soil and wastewater. This kind of emerging pollutant into engineered nanomaterials is riveting. This work proposes the elimination and transformation of a beta-lactam antibiotic, oxacillin, from environmental waste to graphene quantum dots (GQDs). Two protocols were followed in which the use of ethylenediamine (EDA) in the transformation leads to GQDs with excellent optical properties. Therefore, two types of GQDs were synthesized in a Te?on-lined stainless autoclave by a thermal procedure using oxacillin in the absence and presence of EDA. The ensuing e-GQDs from oxacillin and EDA display a stronger ?uorescence emission in comparison to those synthesized without EDA (o-GQDs). The combination of Kaiser test analyses, infrared (IR) and Raman measurements revealed the presence of oxygen-containing groups and primary amines at the edges of the graphitic nanolayer for e-GQDs. This straightforward strategy brings hope and opens a new interest in waste recycling by means of extracting residual contaminants from the environment for their further transformation into adequate non-toxic graphitic nanomaterials with potential applications.
关键词： residues transformation,photoluminescence,antibiotic,removal
更新于2025-09-16 10:30:52
-
The Elite Facial Surgery Practice (Development and Management) || 24 Laser Surgery
摘要： All lasers are not the same. They are tools or instruments that come in a variety of different forms and are designed to perform different tasks. Some lasers vaporize the outer layers of sun-damaged or aging skin. Some can also pass through the outer layers of the skin and destroy deeper birthmarks (port-wine stains) or tiny blood vessels (spider veins.) As is the case with most technology, the use of lasers is an art form that improves with training and experience. Lasers, like any technology, must be used for the right reasons. The right reason is that, in the facial surgeon's opinion, it is superior to other forms of treatment, in terms of safety and outcomes. For some conditions, lasers exceed other forms of treatment. For others, I have found laser therapies to be inferior. So, if training in dermabrasion and chemical peeling was not offered during residency or fellowship, it is recommended that the surgeon arrange to spend enough time with a colleague who performs these procedures to feel comfortable offering and performing them.
关键词： Leg Veins,Rosacea,Laser Surgery,Pigmented Spots,Acne,Laser Hair Removal,Skin Resurfacing,Dilated Blood Vessels
更新于2025-09-16 10:30:52
-
Self-Mixing Interferometric Signal Enhancement Using Generative Adversarial Network for Laser Metric Sensing Applications
摘要： Measurement performance of self-mixing interferometric (SMI) laser sensor can be significantly affected due to the presence of noise. In this case, conventional signal enhancement techniques yield compromised performance due to several limitations which include processing signals in frequency domains only, relying mainly on first order statistics, loss of important information present in higher frequency band and handling limited number of noise types. To address these issues, we propose a solution based on using generative adversarial network, a popular deep learning scheme, to enhance SMI signal corrupted with different noise types. Thus, taking advantage of the deep networks that can learn arbitrary noise distribution from large example set, our proposed method trains the deep network model end-to-end, able to process raw waveforms directly, learn 51 different noise conditions including white noise and amplitude modulation noise for 1,140 different types of SMI waveforms made up of 285 different optical feedback coupling factor (C) values and 4 different line-width enhancement factor α values. The results show that the proposed method is able to significantly improve the SNR of noisy SM signals on average of 19.49, 16.29, 10.34 dB for weak-, moderate-, and strong-optical feedback regime signals, respectively. For amplitude modulated SMI signals, the proposed method has corrected the amplitude modulation with maximum error (using area-under-the-curve based quantitative analysis) of 0.73% for SMI signals belonging to all optical feedback regimes. Thus, our proposed method can effectively reduce the noise without distorting the original signal. We believe that such a unified and precise method leads to enhancement of performance of SMI laser sensors operating under real-world, noisy conditions.
关键词： signal noise removal,neural network for signal enhancement,Interferometry laser sensors,vibration measuring laser sensors,waveform enhancement,self-mixing signal enhancement,generative adversarial network (GAN)
更新于2025-09-16 10:30:52
-
Influence of Pulse Duration on Effective Energy on Material Removal in Micro-processing of Mild Steel by Several Hundred Nanoseconds Pulsed Laser
摘要： A little longer pulse duration more than several hundred nanoseconds is the middle region between ablation and melting removal of material, and effective removal of material can be expected. However, influence of these phenomena on material removal characteristics has not been clarified sufficiently. Therefore, influence of pulse duration and laser intensity on plasma was investigated by measurements of transmittance of laser energy through the plasma. Finally, effective energy to material removal characteristics was discussed with calculated laser energy relating to removal volume of mild steel as a commonly used steel by using several hundred nanoseconds pulsed laser. Transmittance ratio of laser energy was high at long pulse duration in several hundred nanoseconds range under the same pulse energy condition, because there was low reduction rate of laser energy by laser induced plasma. A little long pulse duration could perform efficient processing of mild steel under the same pulse energy condition by using several hundred nanoseconds pulsed laser.
关键词： plasma,removal volume,effective energy,pulse duration,nanosecond pulsed laser
更新于2025-09-16 10:30:52
-
Laser synthesis of magnetite-partially reduced graphene oxide nanocomposites for arsenate removal from water
摘要： Herein, we report the development of a facile process for the synthesis of magnetite-partially reduced graphene oxide (Mag-PRGO) without the use of chemical reducing agents or solvents for the efficient removal of arsenate As(V) ions from contaminated water. The Mag-PRGO is synthesized using the laser vaporization-controlled condensation method where a compressed target consisting of metallic iron (Fe) powder and solid graphene oxide (GO) is laser vaporized in an O2–He atmosphere resulting in the simultaneous oxidation of the Fe nanoparticles and the partial reduction of the GO to form the Mag-PRGO nanocomposite where the magnetic Fe3O4 nanoparticles are anchored to the surface of the PRGO nanosheets. FTIR, Raman, XPS, XRD, TEM, and SEM confirm the successful attachment of the magnetic Fe3O4 nanoparticles to the PRGO nanosheets. The Mag-PRGO (50 wt% Fe) adsorbent shows exceptional selectivity for the extraction of As(V) ions with a capacity of 132 mg/g with no leaching of Fe ions into the solution, placing it among the best carbon-based materials for the efficient removal of As(V) from aqueous solutions. The Mag-PRGO displays a 100% removal of As(V) at concentrations up to 100 ppm with 98% and 100% removal within 15 min and 30 min, respectively, at 50 ppm concentration. The excellent agreement of the experimental sorption isotherms with the Langmuir model suggests a monolayer adsorption behavior. The mechanism of As(V) removal is based on surface complexation between the protonated hydroxyl groups on the surface of Mag-PRGO and the monobasic and dibasic arsenate anions forming (Fe–O–As) bonds as confirmed by FTIR and XPS. The Mag-PRGO is easily regenerated with the desorption of the As(V) ions reaching 99% from their maximum sorption capacities using NaOH. The efficient magnetic separation and high chemical stability of Mag-PRGO are demonstrated over six adsorption–desorption cycles of As(V). The Mag-PRGO is proposed as an excellent remediation adsorbent for the extraction of As(V) from contaminated water.
关键词： Magnetite-partially reduced graphene oxide,Arsenate removal,Water remediation,Adsorption,Laser vaporization-controlled condensation
更新于2025-09-16 10:30:52
-
Using erbium-doped yttrium aluminum garnet laser irradiation in different energy output levels versus ultrasonic in removal of root canal filling materials in endodontic retreatment
摘要： Objectives: The objective of this study was to evaluate the efficacy of erbium?doped yttrium aluminum garnet (Er:YAG) laser irradiation in different energy outputs versus ultrasonic in gutta-percha removal during the endodontic retreatment. Materials and Methods: A total of 21 extracted human lower premolars were divided into three groups (n = 7). Following the standardized preparation of the root canals with Wave One Rotary system and obturation with gutta-percha: Group I was treated with ultrasonic, Group II by Er:YAG laser with 40 mJ/Pulse, and Group III by Er:YAG laser with 50 mJ/Pulse for the removal of gutta?percha from the canals. Two extra teeth were treated by Er:YAG laser with 135 mJ/Pulse as control group. For all groups, time for gutta-percha removal was recorded. Samples were then splited into two halves and tested by scanning electron microscope and stereomicroscopic evaluation under different magnification power to observe the efficacy of each method used in the removal of gutta-percha. Results: Statistical analysis of Kruskal–Wallis suggested that there are significant difference between the groups in relation to removal time (P < 0.05) and 2 × 2 Mann–Whitney U-test among the groups revealed that there is no significant difference between 40 and 50 mJ laser outputs (P > 0.05), but ultrasonic versus 40 and/or 50 mJ laser outputs were significantly different (P < 0.05). Conclusions: Er:YAG laser beam was not so efficient when compared to ultrasonic to reach the deeper parts of the canals as it was asserted, thermal side effects and burning damages were observed on the root canal dentinal walls. Moreover, the delivery system was not flexible enough to compensate the curvature of the canal system even though we used more straight canals as the sample ones as well as more time-consuming than the ultrasonic and more clinical time, rendering it to be less efficient in the removal of the obturation material during endodontic retreatment procedures.
关键词： gutta-percha removal,erbium-doped yttrium aluminum garnet lasers,Endodontics,retreatment,lasers
更新于2025-09-16 10:30:52
-
Data processing for atomic resolution holography
摘要： In photoelectron holography, the intensity of the angular distribution of photoelectrons is measured to obtain a hologram. Thus, a hologram can be defined as a function on a sphere. X-ray fluorescence holography is similar to photoelectron holography. In this study, we describe methods for representing spherical functions that are suitable for atomic resolution holography, and the theory of conversion from the coordinate system of measurement to the various projections. We describe methods for rotational transformations and symmetry operations for atomic resolution hologram and the image composition from measured hologram fragments. In addition, several ways to remove the background from the raw hologram data are discussed.
关键词： atomic resolution holography,photoelectron holography,X-ray fluorescence holography,background removal,spherical functions,symmetry operations,rotational transformations,image composition
更新于2025-09-16 10:30:52
-
Harper's Textbook of Pediatric Dermatology || Laser Therapy
摘要： The pulsed dye laser has revolutionized the treatment of vascular anomalies. More recently, the multiplex laser, a combination of pulsed dye and Nd:YAG, has been shown to be beneficial for recalcitrant port wine stains and other conditions. In addition to their use in treating port wine stains, lasers have also an important role in treating a number of childhood pigmentary disorders. These are primarily congenital naevi such as café‐au‐lait macules, naevus of Ito and some blue lesions. Laser treatment is based on selective thermal destruction or damage to a targeted chromophore located in the skin, either that of blood, melanin or tissue water. Lasers have been shown to successfully treat vascular and pigmented lesions and also remove unwanted hair. They can also be used to remove verrucous lesions such as angiofibromas and epidermal naevi through vaporization.
关键词： pulsed dye laser,vascular anomalies,verrucous lesions,port wine stains,hair removal,selective photothermolysis,pigmentary disorders
更新于2025-09-16 10:30:52