Peri-implantitis is a pathological condition occurring in tissues around dental implants, characterized by inflammation in the peri-implant connective tissue and progressive loss of supporting bone. In the treatment of peri-implantitis, a laser surgical technique is used. Lasers are a safe and gentle alternative to traditional dental tools. They allow oral surgeons and dentists to accomplish more complex tasks, reduce blood loss, decrease post-operative discomfort, reduce the chance of wound infection, achieve better wound healing and perform some procedures in close methods without access flap. The aim of the work was to determine the impact of laser surface treatment of titanium dental implants on its electrochemical behavior in artificial saliva at 37°C. The study used an Er,Cr:YSGG laser and diode lasers 810 nm and 980 nm for debridement of titanium implant surface. In the research, the thread on the surface of implant was scanned with the diode laser beam of energy 1, 1.25, 1.5 and 2 W, cw and Er, Cr YSGG: 1,5 and 2W, pulse 30Hz.
The influence of ion implantation on the structure and properties of polymers is a very complex issue. Many physical and chemical processes taking place during ion bombardment must be taken into consideration. The complexity of the process may exert both positive and negative influence on the structure of the material. The goal of this paper is to investigate the influence of H+, He+ and Ar+ ion implantation on the properties of polypropylene membranes used in filtration processes and in consequence on fouling phenomena. It has appeared that the ion bombardment caused the chemical modification of membranes which has led to decrease of hydrophobicity. The increase of protein adsorption on membrane surface has also been observed.
Effect of annealing on the structural properties of arsenic-implanted mercury cadmium telluride film grown by molecular beam epitaxy was studied with the use of transmission electron microscopy and optical reflection. Strong influence of the graded-gap surface layer grown on top of the film on the behaviour of implantation-induced defects under arsenic activation annealing was revealed and interpreted.
The aim of this article is to present the results of research aimed at confirmation whether it is possible to form an intermediate band in GaAs implantation with H+ ions. The obtained results were discussed with particular emphasis on possible applications in the photovoltaic industry. As it is commonly known, the idea of intermediate band solar cells reveals considerable potential as the most fundamental principle of the next generation of semiconductors solar cells. In progress of the research, a series of GaAs samples were subjected to poly-energy implantation of H+ ions, followed by high-temperature annealing. Tests were conducted using thermal admittance spectroscopy, under conditions of variable ambient temperature, measuring signal frequency in order to localize deep energy levels, introduced by ion implantation. Activation energy ΔE was determined for additional energy levels resulting from the implantation of H+ ions. The method of determining the activation energy value is shown in Fig. 2 and the values read from it are σ0 = 10−9 (Ω·cm)−1 for 1000/T0 = 3.75 K−1 and σ1 = 1.34 × 10−4 (Ω·cm)−1 for 1000/T1 = 2.0 K−1. As a result, we obtain ΔE ≈ 0:58 eV. It was possible to identify a single deep level in the sample of GaAs implanted with H+ ions. Subsequently, its location in the band gap was determined by estimating the value of ΔE. However, in order to confirm whether the intermediate band was actually formed, it is necessary to perform further analyses. In particular, it is necessary to implement a new analytical model, which takes into consideration the phenomena associated with the thermally activated mechanisms of carrier transport as it was described in [13]. Moreover, the influence of certain parameters of ion implantation, post-implantation treatment and testing conditions should also be considered.
Mg-1.6Gd binary alloy was subjected to uniaxial warm rolling at a unidirectional and cross-sectional with a reduction ratio of 95% in order to observe the relationship between its microstructural changes to the degradation behavior. The warm rolling was performed at a temperature range of its recrystallization temperature, which were 400°C and 560°C, and a feed rate of 10 mm/min. Degradation behaviors of Mg-1.6Gd binary alloy was evaluated by means of potentiodynamic polarization and hydrogen evolution test in modified Kokubo’s SBF solution at temperature of 37 ± 1ºC. The lowest corrosion rate of 0.126 mm/year derived from potentiodynamic polarization test was showed by unidirectional-rolled specimen at temperature of 560 °C. Hydrogen evolution test results showed the lowest hydrogen gas formed during 24 hours of immersion was found on unidirectional-rolled specimen at temperature of 560°C with a rate of 0.268 cc/cm2/hours. While cross rolled specimens showed a high corrosion and hydrogen evolution rate of 20 mm/year and 0.28 cc/cm2/hours.
Aortic stenosis is the most common acquired valvular heart disease. Aortic stenosis has growing prevalence in people older than 75 years and natural course of disease is characterized by high mortality rate. According to epidemiological data all patients with aortic stenosis will die after 2–5 years from the first signs of disease if not undergo aortic valve replacement. However, even 40% of patients do not have surgery because of comorbidities related to advanced age. This was the main reason why in 80- and 90-ties of XX century there were intensive attempt to developed an alternative, less invasive treatment methodology for people with aortic stenosis and comorbidities and at high surgical risk. Transcatheter aortic valve implantation (TAVI) was introduced by Dr Alain Cribier in February 2nd, 2002 in Rouen, France. Since that day different aortic transcatheter bioprostheses were used in many randomized clinical trials comparing their safety and effectiveness versus surgical aortic valve replacement. Gradually, it became clear that in all older patients in all risk groups TAVI was equally or even more safe and effective than surgery. Complications after TAVI are relatively rare, but some of them are life-threatening. Heart Team plays a key role in patients selection to TAVI.
Thiswork presents results of comparative studies of the optical absorption coefficient spectra of ion implanted layers in silicon. Three nondestructive and noncontact techniques were used for this purpose: spectroscopic ellipsometry (SE), modulated free carriers absorption (MFCA) and the photo thermal radiometry (PTR). Results obtained with the ellipsometric method are the proof of correctness of the results obtained with the MFCAandPTRtechniques. These techniques are usually used for investigations of recombination parameters of semiconductors. They are not used for investigations of the optical parameters of semiconductors. Optical absorption coefficient spectra of Fe+ and Ge+ high energy and dose implanted layers in silicon, obtained with the three techniques, are presented and compared.