Laser ablation is becoming a dominant technology for direct solid sampling in analytical chemistry. Laser ablation refers to the process in which an intense burst of energy delivered by a short laser pulse is used to sample (remove a portion of) a material. The advantages of laser ablation chemical analysis include direct characterization of solids, no chemical procedures for dissolution, reduc...

Neutral particles ejected from biological material under ultra short laser ablation have been investigated by laser post-ionization time-of-flight mass spectrometry. It could be shown, that beside ionized species, a substantial amount of neutral particles is ejected. A temporal study of the ablation plume is carried out by recording neutral particle time-of-flight mass spectra as a function of ...

Successful Pu disposition by immobilization in glass or ceramic form requires accurate and precise knowledge of impurity amounts. Analysis of Pu material by conventional liquid nebulization requires dissolution, which is difficult due to a refractory nature of the samples. Laser ablation is a suitable sampling technique for direct analysis of solids. This paper demonstrates the procedures that ...

Ultra-high temperature ceramics are desirable for applications in the hypersonic vehicle, rockets, re-entry spacecraft and defence sectors, but few materials can currently satisfy the associated high temperature ablation requirements. Here we design and fabricate a carbide (Zr0.8Ti0.2C0.74B0.26) coating by reactive melt infiltration and pack cementation onto a C/C composite. It displays superio...

Catheters able to measure the force and vector of contact between the catheter tip and myocardium are now available. Pre-clinical work has established that the degree of contact between the radiofrequency ablation catheter and myocardium correlates with the size of the delivered lesion. Excess contact is associated with steam pops and perforation. Catheter contact varies within the left atrium ...

OBJECTIVES To investigate apicectomies performed using burs, a CO2 laser or an Er:YAG laser and to evaluate the following aspects: morphology of apicectomized surfaces, presence of failures at the dentin/obturation material interface (marginal fit) of the apical portions of the root canals, and the proportions of chemical elements in the apicectomized surfaces. STUDY DESIGN Twenty-four teeth ...

Comparative studies of the pulsed laser ablation of graphite in 20 mTorr of N2 using both 15 ns and 450 fs pulses at a wavelength of 248 nm are reported. Emissions from the resulting ablation plumes, and from collisions with ablated material and the background N2 gas molecules, have been investigated by wavelength-, space-, and time-resolved optical emission spectroscopy OES , and the observati...

The model of laser ablation driven by a bulk photothermal reaction is considered. Stationary wave solutions are obtained and analyzed. In the case of a simple photothermal bond-breaking reaction, it is possible to reduce this bulk ablation model to the surface evaporation model with some apparent activation energy. A more complicated model of laser ablation, taking into consideration a photothe...

introduction: the ablation technique is one of the important therapeutic interventions for treatment of av nodal tachyarrhythmia. different animal models have been developed to study the effects of ablation on the functional interanodal structure. the aim of the present study was to develop a new model of computer analysis to produce lesions by using direct voltage in isolated perfused rabbit a...

conclusions radiofrequency ablation may be used successfully in the treatment of parathyroid adenoma when a patient cannot tolerate surgery. case presentation a 47-year-old patient was referred to our hospital (namazi hospital, shiraz, iran) in april, 2015 with intracranial hemorrhage, as well as high serum calcium and pth (parathyroid hormone) levels (12.1 mg/dl and 1062 pg/ml, respectively), ...