Nd-YAG Research Articles

Complex application of high-intensity phototechnologies in the treatment of diffuse alopecia

The purpose of the study. The issues of treatment of patients with diffuse alopecia are being actively investigated at the present time. Promising in this regard are laser technologies, including in combination with drugs, which determined the relevance of this study. The aim of the study was to scientifically substantiate and develop a combined method including fractional laser therapy, intravenous blood irradiation and minoxidil for the treatment of patients with diffuse telogenetic alopecia. Materials and methods. To study the effectiveness of laser technologies, 4 treatment regimens were analyzed. A total of 177 patients with an established diagnosis of diffuse telogenetic alopecia were under observation. To study the effectiveness and safety of the developed combined method, as well as its components, a visual hair loss scale (VSHVV) was used in the study. Results. The best result in patients with mild severity was obtained in the combination therapy group, where the dynamics was 36.9 %. While in the group using erbium and neodymium lasers, the dynamics was 25 %, in the group where percutaneous laser irradiation of blood was used –21.1 %, in the control group — 19.3 %. The best result in patients with severe severity was obtained in the combination therapy group, where the dynamics was 70.8 %. While in the group using erbium and neodymium lasers, the dynamics was 60.8 %, in the group using percutaneous laser irradiation of blood –57.7 %, in the control group 55.7 %. Conclusion. Thus, the developed method of combined therapy of patients with mild and severe diffuse alopecia is highly effective and can be recommended for use in a wide clinical practice.

Using high-intensity phototechnology as a method of treating mild to severe diffuse alopecia

Purpose of the study. Publications on the use of laser technologies are isolated and additional studies on representative samples and with an assessment of the stability of the effects of laser therapy are needed to confirm their effectiveness. The aim of the study was the scientific substantiation and development of a combined method including fractional laser therapy, intravenous blood irradiation and minoxidil for the treatment of patients with diffuse telogen effluvium. Material and methods: To study the effectiveness of laser technologies, 4 treatment regimens were analyzed. A total of 177 patients with an established diagnosis of diffuse telogen effluvium were observed. The work used the DIQOL index (dermatological index of quality of life), which is a universal tool for assessing quality of life indicators in various skin diseases. Results: The data obtained show that the relief of clinical symptoms in diffuse alopecia improves the psycho-emotional state and increases the quality of life of patients, which is confirmed by the improvement in the dynamics of the DIQOL index in all study groups: in the group using erbium and neodymium lasers, the dynamics were 27.2 % / 41.2 %, in the group where transcutaneous laser irradiation of blood was used — 20 % / 29.4 %, in the control group 9.1 % / 23.5 %. The best result was obtained in the combination therapy group, where the dynamics were 45.4 % and 52.9 %, with a mild and severe degree, respectively.

Synthesis of Gold Nanoparticles by Pulsed Laser Ablation and its Study Physical and Mechanical Properties

In this work, the pulsed laser ablation technique was used, which is considered a good and distinctive method. Gold nanoparticles (AuNP) were prepared using an Nd-YAG laser with specific parameters, wavelength 1064 nm, constant ablation energy 1000 mJ, frequency 1 Hz, and different number of pulses (300, 600, and 900 pulse/sec). Deionized water was used as the medium liquid. The purpose of this study was to examine the change in these parameters on AuNP using a variety of Xrd, FESEM, Uv-Vis, force-hardness, and compression measurements. The pure cubic crystal structure of gold nanoparticles was analyzed using XRD. Subsequent FESEM images (average diameters 78.07nm, 49.15nm, 37.67nm) indicate that the particles had highly spherical and quasi-spherical shapes. Using ultraviolet analysis, the absorption band of gold nanoparticles was found and the wavelength was (518, 519, 524) nanometers, respectively. There were three different power gaps (1.895, 2.005, and 2.084) eV. In addition, mechanical property tests were conducted, where 2 ml of gold nanoparticles were mixed with (3 grams) of traditional dental filling. The hardness value increased by (3%). The results also showed an increase in the stress and strain value and an increase in Young’s modulus. Hence, an increase in the compressive strength. This indicates that AuNP affects the mechanical properties and enhances their effectiveness.

Melasma Revisited: National Survey Reveals How Dermatologists Diagnose and Treat This Complex Skin Condition.

Melasma is a chronic condition characterized by dark patches on the facial skin. It has a known female gender dominancy, and women usually think of melasma as being a serious cosmetic problem. Treatment of melasma can be seriously challenging, thus, dermatologists may employ different approaches for melasma. This study aimed to investigate how dermatologists diagnose and treat patients with melasma and to present the general characteristics of patients with melasma. A survey was conducted using Google Forms targeting dermatologists in Turkiye. A total of 199 dermatologists (142 females/57 males) participated in the study. Most of the participants (52.3%) were residents. Majority gender of the patients was female and most common age range of patients with melasma was 30-40 years. Mixed melasma was the most common type (57.4%). Malar region was the most frequent location (58.6%). Wood's lamp examination was used by 25.6% of the participants. Topical treatment was the first-line choice for melasma therapy (95%), with Kligman's formula being the most used topical agent (69.8%). Oral therapy was not used by 70.8% of the participants. Tranexamic acid was the first choice for oral treatment (23.4%). Only 24.9% of the dermatologists used laser/light therapy, and Q-switched Nd-YAG laser was the most preferred device (58%). The most common recurrence rate was 41%-60% (45.9%). The findings of the current study investigating the melasma management in Turkiye revealed a female predominance and peak prevalence in the 30-40 years age group. Kligman's formula is the preferred topical treatment, whereas oral tranexamic acid remains underutilized. Recurrence rates are high, highlighting the need for preventative strategies. This study emphasizes the importance of personalized approaches and ongoing research for effective melasma management.

Anion photoelectron spectroscopy and chemical bonding of ThS2- and ThSO.

Anion photoelectron spectra of ThSO- and ThS2- were recorded using the third (355nm) harmonic of an Nd-YAG laser; these provided the measured vertical detachment energies of each anion. The experiments are supported by extensive coupled cluster calculations on ThSO, ThSO-, ThS2, and ThS2-, as well as the oxygen congeners ThO2 and ThO2-. The abinitio calculations, which included complete basis set extrapolations, spin-orbit effects using four-component coupled cluster, and higher-order correlation contributions through CCSDT(Q), yielded an adiabatic electron affinity for ThO2 that was within 0.02eV of the previously determined experimental value. The singly occupied molecular orbital (SOMO) in all three anions corresponds primarily to the 7s orbital on Th. Successive substitution of S for each O in ThO2 leads to larger electron affinities and smaller bond angles in the neutral molecules, but larger angles in the anions. As demonstrated by Franck-Condon simulations of the spectra using the CCSD(T) spectroscopic constants, substitution of O by S significantly complicates the resulting detachment spectra due to the lower vibrational frequencies in the sulfur species. Overall the calculated vertical detachment energies are in very good agreement with the experiment. In addition to the adiabatic electron affinities of each species, atomization energies and heats of formation have also been determined via the FPD approach with expected uncertainties of 1-2 kcal/mol.

MHD simulations of astrophysical and laboratory jets under different magnetic field configurations

This paper presents the results of MHD simulations of astrophysical and laboratory supersonic jets under a superposition of poloidal (Br, Bz) and toroidal (Bϕ) magnetic fields. It is shown that the escaping matter is quickly collimated by the magnetic field. A shock wave of an elongated shape is formed, which moves from the target to the boundary of the chamber, leaving behind a stable flow. A periodic shock wave structure is observed inside the main conical expanding shock wave. It is shown that the toroidal component of the magnetic field remains in the region throughout the entire calculation and plays a role in the collimation of the flow. The poloidal magnetic field decreases in the region of the jet cone, but remains in the simulation region throughout the calculation and also participates in flow collimation. Thus, both components Bz and Bϕ take part in the collimation of the flow by the magnetic field. The width of the jet and the opening angle of the cone Ɵ depend on the magnitude of the magnetic field induction. As the field increases, the jet becomes narrower and the cone angle decreases. Initially, we do not specify the rotation of the jet Ω. However, due to the presence of the Bϕ field, the substance acquires angular velocity and twists along the z axis. The simulation results are in agreement with laboratory jets arising in the experiment at the Neodymium laser installation, and with the previously obtained results of MHD modeling of jet formation separately, in poloidal or toroidal magnetic field.

تأثير استعمال ليزر النيوديميوم ياك (Nd-YAG) على البنية الدقيقة وصلابة سطح الفولاذ AISI1012

The unique characteristics of the laser beam such as directionality, monochromaticity, and brightness make it a very important tool in the surface treatment engineering. The concentrated heat in the laser beam can be precisely directed toward the processed region on the surface. The laser beam power, beam size, and scanning velocity are easily controlled during the different processing methods. Laser surface modifications of metallic materials, such as laser surface melting, laser surface alloying, and laser cladding are some of the most important methods to improve the mechanical properties of the processed layer on the surface. A pulsed Nd-YAG laser surface melted specimens of low carbon steel with a maximum power of 90W at different processing parameters. The rapid melt and solidification of the treated layer produced a refinement in the microstructure. The original microstructure of this steel (Ferrite + Pearlite) has been transformed to new phases of martensitic and bainitic structures. The melted layer consists of the melted pool, the heat affected zone, and the substrate. The maximum hardness of the laser melted layer is more than 400 HV. The effect of different lasers such as high power CW CO2 laser on the mechanical properties and corrosion resistance of steel alloys will be carried out in future studies. Keywords: Nd-Yag Laser, Laser surface treatment, Microstructure and hardness of AISI1012 steel

Risk factors for early and late retinal detachment after boston type I keratoprosthesis surgery.

To determine the differential risk factors for retinal detachment (RD) after Boston Type 1 Keratoprosthesis (B1KPro) during the first year after surgery (early RD; ERD) and afterwards (late RD; LRD). Retrospective cohort study of 94 eyes (90 patients) undergoing B1KPro implantation at Centro de Oftalmología Barraquer from June 2006 to July 2022 with a minimum follow-up of one year. The incidence of RD in the whole sample after B1KPro implantation was 29% (27/94), occurring in 21% of eyes (ERD; 20/94) the first year, and in 7% afterwards (LRD; 7/94). Hypotony was revealed as a significant risk factor for ERD (16/19 = 84%; OR = 14.5, P < 0.0001), together with aphakia (16/20 = 80%; OR = 5.9, P = 0.004), intraocular lens (IOL) removal (4/8 = 50%; OR = 6.2, P = 0.03), previous choroidal detachment (CD; 7/20 = 35%; OR = 35.5, P = 0.001) and previous pars plana vitrectomy (PPV; 15/20 = 75%; OR = 6.6, P = 0.006). Multivariate analysis included hypotony and PPV at any time as variables significantly associated with ERD occurrence. The occurrence of LRD was significantly related to peripheral retinal changes, detected few days before (4/6 = 66%; OR = 65, P < 0.0001). Hypotony emerged as one of the main factors influencing ERD occurrence after B1KPro implantation. Additionally, previous CD, PPV, aphakia, and IOL removal should be considered to estimate the risk of postoperative retinal detachment. In contrast, peripheral retinal changes after B1KPro seem to be significantly related to LRD occurrence. This study reinforces the need for frequent intraocular pressure evaluation, and comprehensive periodic retinal assessment over time. What is known Retinal detachment (RD) is a severe complication after Boston Type 1 Keratoprosthesis (B1KPro) implantation, resulting in a permanent reduction of visual acuity in a clinically relevant percentage of eyes. The time of RD occurrence after B1KPro implantation differs in the literature but is reported to be more common within the first year. Previous aphakia, choroidal detachment, or RD repair, intraocular lens removal, vitritis, or history of Nd-YAG laser have been described as risk factors for RD after B1KPro surgery in samples with varying follow-ups. Multivariate analysis in the first year after B1KPro surgery showed hypotony and pars plana vitrectomy at any time as significant risk factors for early RD. Late RD cases, occurring after one year following the B1KPro surgery, seem to be significantly related to peripheral retinal changes suffered a few days before loss of visual acuity and RD diagnosis. It is plausible to think that risk factors for RD after B1KPro differ in short and long postoperative times.

Development of a Miniaturized 2-Joule Pulsed Plasma Source Based on Plasma Focus Technology: Applications in Extreme Condition Materials and Nanosatellite Orientation.

Plasma focus devices represent a class of hot and dense plasma sources that serve a dual role in fundamental plasma research and practical applications. These devices allow the observation of various phenomena, including the z-pinch effect, nuclear fusion reactions, plasma filaments, bursts, shocks, jets, X-rays, neutron pulses, ions, and electron beams. In recent years, considerable efforts have been directed toward miniaturizing plasma focus devices, driven by the pursuit of both basic studies and technological advancements. In this paper, we present the design and construction of a compact, portable pulsed plasma source based on plasma focus technology, operating at the ~2-4 Joule energy range for versatile applications (PF-2J: 120 nF capacitance, 6-9 kV charging voltage, 40 nH inductance, 2.16-4.86 J stored energy, and 10-15 kA maximum current at short circuit). The components of the device, including capacitors, spark gaps, discharge chambers, and power supplies, are transportable within hand luggage. The electrical characteristics of the discharge were thoroughly characterized using voltage and current derivative monitoring techniques. A peak current of 15 kiloamperes was achieved within 110 nanoseconds in a short-circuit configuration at a 9 kV charging voltage. Plasma dynamics were captured through optical refractive diagnostics employing a pulsed Nd-YAG laser with a 170-picosecond pulse duration. Clear evidence of the z-pinch effect was observed during discharges in a deuterium atmosphere at 4 millibars and 6 kilovolts. The measured pinch length and radius were approximately 0.8 mm and less than 100 μm, respectively. Additionally, we explore the potential applications of this compact pulsed plasma source. These include its use as a plasma shock irradiation device for analyzing materials intended for the first wall of nuclear fusion reactors, its capability in material film deposition, and its utility as an educational tool in experimental plasma physics. We also show its potential as a pulsed plasma thruster for nanosatellites, showcasing the advantages of miniaturized plasma focus technology.

Determination of third order nonlinearity (n2 & β) of glycine zinc sulphate pentahydrate semi-organic single crystal using two laser radiations at different intensities

AbstarctThe third order nonlinear optical properties i.e. nonlinear refraction (n2), absorption coefficient (β) and third order susceptibility χ(3) of glycine zinc sulphate pentahydrate (GZS) semi-organic single crystal was investigated under the excitation of Q-switched Nd-YAG laser pulsed radiations (λ = 532 nm & 1064 nm) by familiar Z-scan method. The values of nonlinear refraction (n2), at 532 nm were 1.19 × 10−5 (cm2/GW), 2.09 × 10−5 (cm2/GW), 2.27 × 10−5 (cm2/GW), 2.48 × 10−5 (cm2/GW), and 2.55 × 10−5 (cm2/GW) at incident optical beam intensities of 0.76 (GW/cm2), 1.13 (GW/cm2), 1.17 (GW/cm2), 1.63 (GW/cm2) and 1.88 (GW/cm2) respectively while that of values at 1064 nm were 4.31 × 10−5 (cm2/GW), 4.69 × 10−5 (cm2/GW), 5.41 × 10−5 (cm2/GW) and 6.39 × 10−5 (cm2/GW) at incident optical beam intensities of 1.20 (GW/cm2), 1.25 (GW/cm2), 1.32 (GW/cm2) and 1.38 (GW/cm2) respectively. The values of nonlinear absorption coefficient (β) at 532 nm were −1.45 (cm/GW), −0.79 (cm/GW), −0.5 (cm/GW), 0.12 (cm/GW) and 0.64 (cm/GW) at incident optical beam intensities of 0.76 (GW/cm2), 1.13 (GW/cm2), 1.17 (GW/cm2), 1.63 (GW/cm2) and 1.88 (GW/cm2) respectively while that of values at 1064 nm were 0.62 (cm/GW), 0.74 (cm/GW), 0.77 (cm/GW) and 0.81 (cm/GW) at incident optical beam intensities of 1.20 (GW/cm2), 1.25 (GW/cm2), 1.32 (GW/cm2) and 1.38 (GW/cm2) respectively. The values of third order susceptibilities χ(3) at 532 nm were 0.83 × 10−12 (esu), 1.32 × 10−12 (esu), 1.42 × 10−12 (esu), 1.55 × 10−12 (esu) and 1.56 × 10−12 (esu) at intensities of 0.76 (GW/cm2), 1.13 (GW/cm2), 1.17 (GW/cm2), 1.63 (GW/cm2) and 1.88 (GW/cm2) respectively while that of values at 1064 nm were 2.71 × 10−12 (esu), 2.96 × 10−12 (esu), 3.4 × 10−12 (esu) and 4.02 × 10−12 (esu) at incident optical beam intensities of 1.20 (GW/cm2), 1.25 (GW/cm2), 1.32 (GW/cm2) and 1.38 (GW/cm2) respectively. It was seen that the sample showing saturable absorber to reverse saturable absorber at 532 nm wavelength at incident optical beam peak intensity (I0) of 1.53 GW/cm2. Thus the crystal could be a potential candidate of optical switching application. It was also seen that the material possess positive nonlinearity. It was also found that the values of nonlinear absorption coefficient (β) and nonlinear refraction (n2) increase with increase of excitation intensity irrespective of excitation wavelengths.

Removal of black tattoos by Picosecond Q-switched Nd-YAG laser in the middle eastern skin type IV: prospective study

Tattoo removal is considered a challenging field in cosmetic dermatology. Picosecond Q-switched Nd-YAG lasers targeting unique chromophores effectively manage this condition without serious complications. To evaluate the efficacy and safety of Picosecond Q-switched Nd-YAG laser in the treatment of black tattoos in the skin of middle eastern mostly skin type IV. The study was carried out on 20 patients with skin type IV the most common in middle eastern area with professional black tattoos. They were treated by Picosecond Nd-YAG laser (2 sessions 8 weeks apart). The percentage of improvement ranged from 20.0 to 95.0 (with a mean of 61 ± 24.6). 8 patients (40%) showed excellent improvement, 4 patients (20%) showed marked improvement, 4 patients (20%) showed moderate improvement, and 4 patients (20%) showed mild improvement. No severe side effects were detected. Picosecond Nd-YAG laser was an effective and safe technique in the treatment of professional black tattoos; with only 2 sessions most patients reached excellent to moderate response with minimal side effects.

The effectiveness of a combination of neodymium laser (ND:yag 1064 nm) and plasma therapy in the treatment of immature striae

Objective. Сorrection of stretch marks is a pressing problem in dermatology and cosmetology due to their widespread prevalence and negative impact on the quality of life of patients. Early treatment for stretch marks is more effective and allows you to achieve an acceptable aesthetic result in a shorter period. Purpose. To compare the effectiveness of treatment of red (young) stretch marks using a neodymium Nd:YAG 1064 nm laser, plasma therapy and their combination. Material and methods: The study included 66 people with immature striae, who were divided into three compared groups: in group I, patients were treated using a neodymium laser (Nd:YAG 1064 nm), in group II — using injections of plasma therapy (PT), in group III, a combined effect was used to correct stretch marks — the use of Nd:YAG 1064 nm and plasma therapy. The study used both integral indicators, such as the DISHS and SKINDEX-29 scales, and specialized diagnostic methods, including measuring the thickness of the dermis using ultrasound diagnostics of the skin, examining the skin using the Aramo ASW-300 apparatus, and assessing microcirculation indicators in the lesions. Results: All therapeutic approaches used in this study demonstrated significant clinical efficacy in the treatment of immature striae. If comparable improvement was observed in the Nd:YAG 1064 nm and plasma therapy groups, then their combination was more effective in all compared characteristics. At the same time, in comparison with Nd:YAG 1064 nm, the use of plasma therapy in the treatment of stretch marks showed greater effectiveness in influencing the quality characteristics of the skin — hydration and elasticity. At the same time, in the Nd:YAG 1064 nm group there was a more pronounced decrease in the size of red striae. Conclusion: A combined technique using Nd:YAG 1064 nm laser exposure and plasma therapy allows one to simultaneously influence various parts of the pathogenesis of striae, which helps to achieve a more pronounced clinical result.

Laser technologies in the treatment of patients with a combination of rosacea subtypes: comparative data

Phototechnologies occupy a leading position in the treatment of patients with rosacea. The most effective technologies are laser: pulsed dye laser (585nm, 595nm) and neodymium laser (1064nm), however, issues of comparative analysis, including in patients with a combination of rosacea subtypes, require further study.Material and methods. We observed 64 patients with diagnosed rosacea with a combination of subtypes: erythematotelangiectatic and papulopustular. Among them, 48 (75%) were female and 16 (25%) were male. The age of the patients varied widely: from 31 to 57 years, the average age was 39.2±4.6 years. The average duration of the disease was 5.1±2.3 years. Depending on the therapy, patients were divided into 2 groups: group 1 received treatment with a neodymium laser, group 2 – treatment with a pulsed dye laser.Research results. A cumulative assessment taking into account clinical research methods with a sufficient degree of reliability revealed the advantages of a neodymium laser over a pulsed dye laser, regardless of the clinical picture of rosacea, which was confirmed by the dynamics of the IGA/PGA indices: reduction in group 1 was 79.5%/66.7%, in group 2–63.2%/51.3%, respectively. These data were confirmed by the dynamics of the DIQI index – 81.7% and 61.6%, respectively.

Droplet Velocity Measurement Of Acetone-Water Spray Using Fluorescence-Based Particle Image Velocimetry

A method for measuring the velocity of liquid droplets emanating from an effervescent injector into ambient air was experimented using a mixture of acetone and water. Conventional methods such as Laser Doppler Velocimetry and Particle Image Velocimetry, which utilise Mie-scattering, have limitations due to multiple scattering and strong surface reflections, respectively. In the current study, we demonstrate fluorescence-based particle image velocimetry, which can overcome the abovementioned difficulty. Unlike previous similar studies that used fluorescent dyes, the inherent fluorescence of acetone is utilised in our strategy. The acetone and water were mixed in different volume ratios, and the effervescent jet was produced with air. The Gas-to-Liquid ratio of 8% was considered in this study. The spray droplets were excited using the fourth harmonic of the Nd-YAG laser. Two acetone Planar Laser laser-induced fluorescence images are acquired with a CCD camera and with a 20 µs time difference. The velocity vectors are obtained based on the cross-correlation between the two images. The results showed that absorption greatly influences the estimated velocity distribution. At a low acetone concentration, the velocity distribution became uniform around the jet centre line. A high-intensity laser could improve the velocity estimate in the core of the aerated jet. The proposed method can be applied directly to ambient and pressurised conditions where wall scattering is dominant. The directional independence of the fluorescence is also an advantage in scenarios where the imaging angle is a constraint.

Combined low-dose isotretinoin and long-pulsed nd: YAG laser in the treatment of post-acne erythema

Post-acne erythema (PAE) is a bothering skin condition that emerges from inflammatory acne and persists after its resolution. It is characterized by telangiectasia and erythematous macules. the role of 1064-nm Nd: YAG when combined with low-dose isotretinoin in the acne erythema treatment. forty-eight PAE patients were involved in the study. They were divided into two groups; group (A) patients administering a low dose of oral isotretinoin (10 mg/day) and underwent a total of six two-week interval sessions of 1064 ND-YAG laser treatment, group (B) patients administering a low dose of oral isotretinoin (10 mg/day) only. All adverse effects experienced during the course of therapy were documented, and photos were taken before the start of the treatment and following the end of the treatment duration. Following the completion of the therapeutic intervention, a significant improvement in clinical condition was observed in both groups, with more improvement in group (A) compared to group (B) as evidenced by a notable improvement in the score on the Clinician Erythema Assessment Scale (CEAS) and also a significant decrease in the mean value of optical density of the erythema. combined 1064-nm Nd: YAG with low-dose isotretinoin may be an efficient and secure line in the PAE treatment. Also, the combined therapy had superior results when compared to low-dose isotretinoin alone.

Qualitative Geochemical Analysis of the 2004 Indian Ocean Giant Tsunami Deposits Excavated at Seungko Mulat Located in Aceh Besar of Indonesia Using Laser-Induced Breakdown Spectroscopy

Laser-induced breakdown spectroscopy (LIBS) was employed to characterize the geochemical signatures layer by layer of 2004 Indian Ocean tsunami deposits in Seungko Mulat Village, Aceh Province, Indonesia. In the LIBS experimental setup, a Nd-YAG laser beam is directed towards the deposit samples, and the resulting atomic emission lines from the laser-induced plasma are captured using a spectrometer. Our analysis reveals terrestrial indicators (Fe), heavy metals (Cu, Cr, Co, Cd), and increased emission intensity of Mg, Ca, Al, K, Si, Ba, N, and O in the 2004 Indian Ocean tsunami layers. The emission intensity ratios of several elements in the 2004 Indian Ocean tsunami deposit layers, namely Ca/Ti, Si/Ti, and K/Ti, unveil notable disparities among the elements evaluated. This indicates the possibility of utilizing these ratios as reliable geochemical markers to differentiate the layer by layer of tsunami deposits. LIBS surpasses XRF in detecting nearly all elements simultaneously and identifying both light elements and specific heavy metals (Ba, Cu, Cr, Co, Cd, Pb, Ni, V, W), exceeding XRF's detection capabilities. This study emphasizes the effectiveness of LIBS as an advanced optical technique, offering speed and promise in analyzing layer-by-layer geochemical markers of the 2004 Indian Ocean tsunami deposits in Seungko Mulat Village.

Long Pulsed Nd-YAG Lasers versus Q Switched Nd-YAG Lasers in the treatment of recalcitrant Plantar Warts - Comparative Randomized Study

Long Pulsed Nd-YAG Lasers versus Q Switched Nd-YAG Lasers in the treatment of recalcitrant Plantar Warts - Comparative Randomized Study

Study of optical properties birefringent of hema - DR13

The following paper is a detailed study of the optical properties of HEMA-DRI3 from optical birefringence can be induced azopolymeric material. Based on the method of two-photon absorption, anisotropy is generated due to the reorientation of the chromophores in the sample of HEMA-DR13. Using allow-power laser He-Ne, and a laser Nd-YAG medium power, it was possible to implement an optical system which allows observing the subsequent quantification of photoinduced bireftingence in said material. Subsequently comparing the results obtained with different theoretical models, thereby determining the characteristic times (time of excitation and relaxation time) of HEMA-DR13. Additionally, a study of the response signal based on the excitation power and the temperature of the material being able to obtain the relationship between this variables and the intensity of bircfringence.

Kinetics of Laser-Induced Thermal Emission of Porous Carbon Materials: Dependence on Laser Wavelength

For the porous carbon material excited by the first and second harmonics of a neodymium laser, the shape of pulsed signals of laser-induced thermal emission is investigated. It is found that the duration of thermal emission pulses significantly depends on the wavelength of the laser excitation, which is caused by the differences in the depth of penetration of laser radiation into the surface layer. The mentioned effect is actual, if the penetration depth of laser radiation exceeds the length of thermal diffusion in the studied material for a time of the order of the laser pulse duration. The computer modeling is carried out for the processes of pulsed laser heating and formation of thermal emission signal. The simulation results showed satisfactory agreement with the measurement results.

Pyrolysis of Brown Coal Microparticles under the Action of Nanosecond First-Harmonic Pulses from a Neodymium Laser

Pyrolysis of Brown Coal Microparticles under the Action of Nanosecond First-Harmonic Pulses from a Neodymium Laser